U.S. patent application number 16/836084 was filed with the patent office on 2020-07-16 for deformed web materials.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to John Joseph Curro, John Lee Hammons, Jill Marlene Orr, Keith Joseph Stone, John Brian Strube.
Application Number | 20200224429 16/836084 |
Document ID | / |
Family ID | 46046339 |
Filed Date | 2020-07-16 |
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United States Patent
Application |
20200224429 |
Kind Code |
A1 |
Hammons; John Lee ; et
al. |
July 16, 2020 |
Deformed Web Materials
Abstract
Deformed web materials are disclosed. The web materials have
discrete deformations formed therein. The deformations may be
features in the form of portions of a web with apertures therein,
protrusions, depressed areas, and combinations thereof. These
features may extend out from the surface on one side of the web, or
from both of the surfaces of the web. Different features may be
intermixed with one another.
Inventors: |
Hammons; John Lee;
(Hamilton, OH) ; Orr; Jill Marlene; (Liberty
Township, OH) ; Curro; John Joseph; (Cincinnati,
OH) ; Strube; John Brian; (Okeana, OH) ;
Stone; Keith Joseph; (Fairfield, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
46046339 |
Appl. No.: |
16/836084 |
Filed: |
March 31, 2020 |
Related U.S. Patent Documents
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Application
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Filing Date |
Patent Number |
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14957637 |
Dec 3, 2015 |
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16836084 |
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13094185 |
Apr 26, 2011 |
9220638 |
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14957637 |
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12879567 |
Sep 10, 2010 |
8557169 |
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13094185 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 66/81433 20130101;
B32B 2555/00 20130101; B26F 1/26 20130101; B26F 1/24 20130101; B29C
66/72328 20130101; E04B 2002/7483 20130101; B29C 59/06 20130101;
E04F 13/0812 20130101; A47B 96/20 20130101; A47B 2096/207 20130101;
A61F 13/5121 20130101; B29C 66/919 20130101; A61F 2013/5386
20130101; B29C 66/81457 20130101; B29C 66/81435 20130101; B31F 1/07
20130101; D04H 11/08 20130101; B29C 66/83413 20130101; B31F
2201/0738 20130101; B32B 3/28 20130101; D04H 1/76 20130101; B29C
66/83411 20130101; B29C 66/91421 20130101; B31F 2201/0733 20130101;
B32B 2307/726 20130101; B31F 2201/0754 20190101; B29C 66/71
20130101; B29C 66/83415 20130101; B29C 66/83513 20130101; B32B
27/20 20130101; B29C 66/82661 20130101; B29L 2009/00 20130101; Y10T
428/24281 20150115; B29C 55/18 20130101; B29C 65/56 20130101; B29C
66/72343 20130101; E04B 2/7422 20130101; B32B 5/022 20130101; B29C
66/83511 20130101; A61F 13/51104 20130101; B29C 59/04 20130101;
B29C 66/45 20130101; E04F 13/0805 20130101; B29C 66/8266 20130101;
B29L 2031/4878 20130101; B32B 3/266 20130101; B29C 66/21 20130101;
Y10T 428/24636 20150115; B29C 65/18 20130101; E04B 2002/7462
20130101; B29C 59/022 20130101; B32B 2307/728 20130101; D04H 3/07
20130101; Y10T 428/24273 20150115; B32B 3/30 20130101; B32B 2432/00
20130101; B32B 2439/00 20130101; A61F 13/15707 20130101; B29C
66/7294 20130101; B32B 7/02 20130101; B29C 66/71 20130101; B29K
2023/06 20130101; B29C 66/71 20130101; B29K 2023/12 20130101 |
International
Class: |
E04F 13/08 20060101
E04F013/08; A47B 96/20 20060101 A47B096/20; E04B 2/74 20060101
E04B002/74 |
Claims
1. A web material comprising a nonwoven, said web material having
discrete features formed therein, said web material having a first
surface and a second surface, said web material comprising: a)
substantially undeformed regions, said substantially undeformed
regions having surfaces that correspond to the first and second
surfaces of said web material; b) a plurality of spaced apart
discrete first macroscopic features comprising at least one of the
following: portions of said web material with apertures therein;
protrusions; and depressions; and c) a plurality of spaced apart
discrete second macroscopic features comprising at least one of the
following: portions of said web material with apertures therein;
protrusions; and depressions; wherein said first features comprise
at least one of a different type and a different property than the
second features, and at least some of said second features are
intermixed with said first features, and said first features and
said second features extend outward in the same direction from one
of the surfaces of the web material.
2. A web material comprising a nonwoven, said web material having
discrete features formed therein, said web material having a first
surface and a second surface, said web material comprising: a)
substantially undeformed regions, said substantially undeformed
regions having surfaces that correspond to the first and second
surfaces of said web material; b) a plurality of spaced apart
discrete first macroscopic features comprising at least one of the
following: portions of said web material with apertures therein;
protrusions; and depressions; and c) a plurality of spaced apart
discrete second macroscopic features comprising at least one of the
following: portions of said web material with apertures therein;
protrusions; and depressions; wherein said first features comprise
at least one of a different type and a different property than the
second features, and at least some of said second features are
intermixed with said first features, wherein said first features
are arranged in rows having a spacing between said rows, and a
majority of said second features are located between the rows of
first features.
3. The web material of claim 2 wherein a majority of said second
features are located a distance of about half way between the rows
of first features.
4. A web material comprising a nonwoven, said web material having
discrete features formed therein, said web material having a first
surface and a second surface, said web material comprising: a)
substantially undeformed regions, said substantially undeformed
regions having surfaces that correspond to the first and second
surfaces of said web material; b) a plurality of spaced apart
discrete first macroscopic features, at least some of which
comprise protrusions; and c) a plurality of spaced apart discrete
second macroscopic features, at least some of which comprise
portions of said web material with apertures therein; wherein at
least some of said second features are intermixed with said first
features.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to deformed web materials
and apparatuses and methods for deforming a web to create such
materials.
BACKGROUND OF THE INVENTION
[0002] Various methods and apparatuses for deforming webs are
disclosed in the patent literature. Patents disclosing such methods
include: U.S. Pat. No. 4,189,344, Busker; U.S. Pat. No. 4,276,336,
Sabee; U.S. Pat. No. 4,609,518, Curro; U.S. Pat. No. 5,143,679,
Weber; U.S. Pat. No. 5,562,645, Tanzer; U.S. Pat. No. 5,743,999,
Kamps; U.S. Pat. No. 5,779,965, Beuether, et al.; U.S. Pat. No.
5,998,696, Schone; U.S. Pat. No. 6,332,955, Meschenmoser; U.S. Pat.
No. 6,739,024 B1, Wagner; U.S. Patent Application Publication
2004/0110442 A1, Rhim; EP 1 440 197 B1, Thordahl; U.S. Pat. No.
6,916,969, Helmfridsson; U.S. Patent Application Publication No.
2006/0151914 A1, Gerndt; U.S. Pat. No. 7,147,453 B2, Boegli; U.S.
Pat. No. 7,423,003, Volpenhein; U.S. Pat. No. 7,323,072 B2,
Engelhart, et al.; U.S. Patent Application Publication No.
2006/0063454, Chung; U.S. Patent Application Publication No.
2007/0029694 A1, Cree, et al.; U.S. Patent Application Publication
No. 2008/0224351 A1, Curro, et al.; U.S. Patent Application
Publication No. 2009/0026651 A1, Lee, et al.; U.S. Pat. No.
7,521,588 B2, Stone, et al.; and U.S. Patent Application
Publication No. 2010/0201024 A1, Gibson, et al.
[0003] However, the search continues for methods and apparatuses
that are capable of forming new structures in webs that provide the
webs with additional properties. In the case of webs used in
absorbent articles, such new structures may include those that
provide a single portion of the web with dual, or more, properties
(such as improved softness, fluid handling, or other properties) in
a predetermined portion of the web. A need also exists for
apparatuses that will allow a web to be deformed multiple times
while maintaining control over the registration of the deformations
in the web. A further need exists for apparatuses that are capable
of deforming a web multiple times with an apparatus that has a
small footprint on a manufacturing floor.
SUMMARY OF THE INVENTION
[0004] The present invention is directed to deformed web materials
and apparatuses and methods for deforming a web to create such
materials. Such materials can be provided as components of products
such as absorbent articles (such as topsheets, backsheets,
acquisition layers, liquid handling layers, absorbent cores),
packaging (such as flow wrap, shrink wrap, and polybags), trash
bags, food wrap, wipes, facial tissue, toilet tissue, paper towels,
and the like. There are numerous non-limiting embodiments of the
present invention.
[0005] In one non-limiting embodiment, the deformed web material
comprises a web having discrete deformations formed therein. The
deformations may be features in the form of portions of the web
with apertures therein, protrusions, depressed areas, and
combinations thereof. These features may extend out from the
surface on one side of the web, or from both of the surfaces of the
web. Different features may be intermixed with one another.
[0006] The apparatuses and methods can, in certain non-limiting
embodiments, be configured for deforming a web in a single nip. In
one embodiment, the method involves feeding a web into a nip that
is formed between two intermeshing rolls. The two rolls are
configured for deforming a web with at least two sets of
deformations that are oriented in different directions relative to
the surfaces of the web.
[0007] In other embodiments, the apparatuses and methods can be
configured for deforming a web at least two times (that is, in at
least two or more nips). In such embodiments, the apparatus may
comprise nested, or other arrangements of, multiple rolls in which
the web may be maintained substantially in contact with at least
one of the rolls throughout the process, and at least two of the
rolls define two or more nips thereon with other rolls. In some
embodiments, rolls can be used to expose a different side of the
web for a subsequent deformation step. In these or other
embodiments, the rolls can be used to transfer the web between
rolls in such a manner that it may offset the rolls and/or web so
that subsequent deformations are formed at a different
cross-machine direction alignment than prior deformations. In some
cases, this may be used to achieve a tighter spacing between
deformations than might otherwise be possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The following detailed description will be more fully
understood in view of the drawings in which:
[0009] FIG. 1 is a schematic side view of a prior art method and
apparatus for deforming a web.
[0010] FIG. 2 is a schematic side view of another prior art
apparatus for deforming a web.
[0011] FIG. 3 is a schematic side view of another prior art method
and apparatus for deforming a web.
[0012] FIG. 4 is a schematic side view of one embodiment of a
method and apparatus for deforming a web.
[0013] FIG. 4A is a schematic side view of an alternative
embodiment of a method and apparatus for deforming a web wherein a
second web is introduced at a nip downstream of the first nip.
[0014] FIG. 5 is an enlarged perspective view of a pair of ring
rolls suitable for use in the methods and apparatuses described
herein.
[0015] FIG. 6 is an enlarged perspective view of a pair of rolls
suitable for use in the methods and apparatuses described herein
comprising a ring roll and a SELF roll.
[0016] FIG. 6A is an enlarged perspective view of a CD SELF roll
with a staggered pattern of teeth thereon.
[0017] FIG. 6B is a cross-section of a portion of the intermeshing
rolls shown in FIG. 6.
[0018] FIG. 6C is an enlarged perspective view of a MD SELF roll
with a staggered pattern of teeth thereon.
[0019] FIG. 7 is an enlarged perspective view of a pair of rolls
suitable for use in the methods and apparatuses described herein
comprising a ring roll and an RKA roll.
[0020] FIG. 8 is a fragmented cross-sectional view through a
portion of the nip between a pair of rolls suitable for use in the
methods and apparatuses described herein which comprise male/female
embossing rolls.
[0021] FIG. 9 is an enlarged perspective view of a portion of the
surfaces of a pair of rolls suitable for use in the methods and
apparatuses described herein.
[0022] FIG. 9A is a perspective view of a portion of a forming
structure having various forming elements.
[0023] FIG. 10 is a schematic side view of another embodiment of a
method and apparatus for deforming a web in which the web wraps at
least 180 degrees around one of the rolls.
[0024] FIG. 11 is a schematic side view of another embodiment of a
method and apparatus for deforming a web in which the apparatus
comprises a hybrid roll arrangement.
[0025] FIG. 12 is a schematic side view of another embodiment of a
method and apparatus for deforming a web in which the apparatus
comprises a closed loop roll arrangement.
[0026] FIG. 13 is a schematic side view of another embodiment of a
method and apparatus for deforming a web in which the apparatus
comprises a shared bank roll arrangement.
[0027] FIG. 14 is an enlarged perspective view of a pair of rolls
for use in an apparatus in which one roll is a staggered "raised
ridge" rotary knife aperturing (or "RKA") roll and the other roll
is a staggered CD SELF roll.
[0028] FIG. 14A is an enlarged perspective view of a portion of the
surface of the raised ridge RKA roll shown in FIG. 14.
[0029] FIG. 14B is an enlarged perspective view of a portion of the
surface of a raised ridge SELF roll, which could be used in a
process such as that shown in FIG. 14.
[0030] FIG. 14C is an enlarged perspective view of the nip formed
between the pair of rolls shown in FIG. 14.
[0031] FIG. 14D is an enlarged side view of a portion of the
surface of an alternative raised ridge RKA roll shown in FIG.
14.
[0032] FIG. 15 is a top perspective view of one example of a web
that can be formed by using a variation of the rolls in FIG.
14.
[0033] FIG. 16 is a schematic side view of another embodiment of a
method and apparatus for deforming a web.
[0034] FIG. 16A is an enlarged partially fragmented cross-sectional
view of the teeth of the first and second rolls of the apparatus
shown in FIG. 16 taken along lines 16A-16A.
[0035] FIG. 16B is an enlarged partially fragmented cross-sectional
view of the teeth of the second and third rolls of the apparatus
shown in FIG. 16 taken along lines 16B-16B.
[0036] FIG. 16C is an enlarged partially fragmented cross-sectional
view of the teeth of the third and fourth rolls of the apparatus
shown in FIG. 16 taken along lines 16C-16C.
[0037] FIG. 17 is a top perspective view of one example of a web
that can be formed by using the rolls in FIG. 16 in which the first
and last rolls have a staggered pattern of forming elements
thereon.
[0038] FIG. 18 is a top perspective view of one example of a web
that can be formed by using the rolls in FIG. 16 in which the first
and last rolls have a standard (or linear) pattern of forming
elements thereon.
[0039] FIG. 19 is a schematic side view of another embodiment of a
method and apparatus for deforming a web.
[0040] FIG. 19A is an enlarged partially fragmented cross-sectional
view of the teeth of the first and second rolls of the apparatus
shown in FIG. 19 taken along lines 19A-19A.
[0041] FIG. 19B is an enlarged partially fragmented cross-sectional
view of the teeth of the second and third rolls of the apparatus
shown in FIG. 19 taken along lines 19B-19B.
[0042] FIG. 19C is an enlarged partially fragmented cross-sectional
view of the teeth of the third and fourth rolls of the apparatus
shown in FIG. 19 taken along lines 19C-19C.
[0043] FIG. 20 is a top perspective view of one example of a web
that can be formed by using the rolls in FIG. 19.
[0044] FIG. 21 is a schematic side view of another embodiment of a
method and apparatus for deforming a web.
[0045] FIG. 21A is an enlarged partially fragmented cross-sectional
view of the teeth of the first and second rolls of the apparatus
shown in FIG. 21 taken along lines 21A-21A.
[0046] FIG. 21B is an enlarged partially fragmented cross-sectional
view of the teeth of the second and third rolls of the apparatus
shown in FIG. 21 taken along lines 21B-21B.
[0047] FIG. 21C is an enlarged partially fragmented cross-sectional
view of the teeth of the third and fourth rolls of the apparatus
shown in FIG. 21 taken along lines 21C-21C.
[0048] FIG. 21D is an enlarged partially fragmented cross-sectional
view of the teeth of the fourth and fifth rolls of the apparatus
shown in FIG. 21 taken along lines 21D-21D.
[0049] FIG. 22 is a top perspective view of one example of a web
that can be formed by using the rolls in FIG. 21.
[0050] FIG. 23 is top perspective view of one example of a web that
can be formed by MD phasing rolls with a staggered pattern using
the apparatus shown in FIG. 2 or 4.
[0051] FIG. 24 is a schematic side view of a web that comprises a
laminate of a nonwoven and film in which the film is located within
one of the tufts and is not formed within another tuft.
[0052] The embodiments shown in the drawings are illustrative in
nature and are not intended to be limiting of the invention defined
by the claims. Moreover, the features of the invention will be more
fully apparent and understood in view of the detailed
description.
DETAILED DESCRIPTION
Definitions
[0053] The term "absorbent article" includes disposable articles
such as sanitary napkins, panty liners, tampons, interlabial
devices, wound dressings, diapers, adult incontinence articles,
wipes, and the like. Still further, the absorbent members produced
by the methods and apparatuses disclosed herein can find utility in
other webs such as scouring pads, dry-mop pads (such as
SWIFFER.RTM. pads), and the like. At least some of such absorbent
articles are intended for the absorption of body liquids, such as
menses or blood, vaginal discharges, urine, and feces. Wipes may be
used to absorb body liquids, or may be used for other purposes,
such as for cleaning surfaces. Various absorbent articles described
above will typically comprise a liquid pervious topsheet, a liquid
impervious backsheet joined to the topsheet, and an absorbent core
between the topsheet and backsheet.
[0054] The term "absorbent core", as used herein, refers to the
component of the absorbent article that is primarily responsible
for storing liquids. As such, the absorbent core typically does not
include the topsheet or backsheet of the absorbent article.
[0055] The term "absorbent member", as used herein, refers to the
components of the absorbent article that typically provide one or
more liquid handling functionality, e.g., liquid acquisition,
liquid distribution, liquid transportation, liquid storage, etc. If
the absorbent member comprises an absorbent core component, the
absorbent member can comprise the entire absorbent core or only a
portion of the absorbent core.
[0056] The term "absorbent structure", as used herein, refers to an
arrangement of more than one absorbent component of an absorbent
article.
[0057] The term "adjacent", as used herein, with reference to
features or regions, means near or close to, and which need not be
in contact with each other.
[0058] The term "aperture", as used herein, refers to a hole. The
apertures can either be punched cleanly through the web so that the
material surrounding the aperture lies in the same plane as the web
prior to the formation of the aperture (a "two dimensional"
aperture), or holes formed in which at least some of the material
surrounding the opening is pushed out of the plane of the web. In
the latter case, the apertures may resemble a protrusion or
depression with an aperture therein, and may be referred to herein
as a "three dimensional" aperture, a subset of apertures.
[0059] The term "component" of an absorbent article, as used
herein, refers to an individual constituent of an absorbent
article, such as a topsheet, acquisition layer, liquid handling
layer, absorbent core or layers of absorbent cores, backsheets, and
barriers such as barrier layers and barrier cuffs.
[0060] The term "cross-machine direction" or "CD" means the path
that is perpendicular to the machine direction in the plane of the
web.
[0061] The term "deformable material", as used herein, is a
material which is capable of changing its shape or density in
response to applied stresses or strains.
[0062] The term "discrete", as used herein, means distinct or
unconnected. When the term "discrete" is used relative to forming
elements on a forming member, it is meant that the distal (or
radially outwardmost) ends of the forming elements are distinct or
unconnected in all directions, including in the machine and
cross-machine directions (even though bases of the forming elements
may be formed into the same surface of a roll, for example).
[0063] The term "disposable" is used herein to describe absorbent
articles and other products which are not intended to be laundered
or otherwise restored or reused as an absorbent article or product
(i.e., they are intended to be discarded after use and, preferably,
to be recycled, composted or otherwise disposed of in an
environmentally compatible manner).
[0064] The term "forming elements", as used herein, refers to any
elements on the surface of a forming member that are capable of
deforming a web. The term "forming elements" includes both
continuous or non-discrete forming elements such as the ridges and
grooves on ring rolls, and discrete forming elements.
[0065] The term "intermixed", as used herein, refers to features
that are distributed between other features over at least some
portion of the surface of a component, in which the features differ
from each other as described herein. The term "intermixed"
comprises arrangements of features in which at least two of the
closest features in any direction (including, but not limited to
longitudinal, transverse, or diagonal) differ from each other as
described herein, even though there may be a similar feature that
is as close as, or closer to, a given feature in another
direction.
[0066] The term "Interpenetrating SELF" and the acronym "IPS", as
used herein, refers to a process that uses The Procter & Gamble
Company's SELF technology (described below) to combine at least two
layers or materials together. Tufts may be formed in both
materials; or, the tuft of one material may burst through the other
material. Interpenetrating SELF is described in greater detail in
U.S. Pat. No. 7,648,752.
[0067] The term "joined to" encompasses configurations in which an
element is directly secured to another element by affixing the
element directly to the other element; configurations in which the
element is indirectly secured to the other element by affixing the
element to intermediate member(s) which in turn are affixed to the
other element; and configurations in which one element is integral
with another element, i.e., one element is essentially part of the
other element. The term "joined to" encompasses configurations in
which an element is secured to another element at selected
locations, as well as configurations in which an element is
completely secured to another element across the entire surface of
one of the elements. The term "joined to" includes any known manner
in which elements can be secured including, but not limited to
mechanical entanglement.
[0068] The term "layer" is used herein to refer to an absorbent
member whose primary dimension is X-Y, i.e., along its length (or
longitudinal direction) and width (or transverse direction). It
should be understood that the term "layer" is not necessarily
limited to single layers or sheets of material. Thus the layer can
comprise laminates or combinations of several sheets or webs of the
requisite type of materials. Accordingly, the term "layer" includes
the terms "layers" and "layered".
[0069] The term "machine direction" or "MD" means the path that
material, such as a web, follows through a manufacturing
process.
[0070] The term "male/female embossing" as used herein, refers to
an embossing apparatus and process that involves the use of at
least a pair of patterned rolls, wherein the first patterned roll
comprises one or more projections or protrusions, and the second
patterned roll comprises one or more recesses into which one or
more of the projections of the first patterned roll mesh. The
projections and recesses may be discrete embossing elements, and
they may have matched or unmatched patterns. The term "male/female
embossing", thus, excludes embossing processes that utilize the
combination of a patterned roll against a flat anvil roll or
deformable roll.
[0071] The term "macroscopic", as used herein, refers to structural
features or elements that are readily visible and distinctly
discernable to a human having 20/20 vision when the perpendicular
distance between the viewer's eye and the web is about 12 inches
(30 cm). Conversely, the term "microscopic" refers to such features
that are not readily visible and distinctly discernable under such
conditions.
[0072] The terms "mechanically impacting" or "mechanically
deforming", may be used interchangeably herein, to refer to
processes in which a mechanical force is exerted upon a
material.
[0073] The term "Micro-SELF" is a process that is similar in
apparatus and method to that of the SELF process defined herein.
Micro-SELF teeth have different dimensions such that they are more
conducive to forming tufts with openings on the leading and
trailing ends. A process using micro-SELF to form tufts in a web
substrate is disclosed in U.S. Patent application Publication No.
US 2006/0286343A1.
[0074] The term "permanently deformed", as used herein, refers to
the state of a deformable material whose shape or density has been
permanently altered in response to applied stresses or strains.
[0075] The term "post-consumer recycled material" as used herein
generally refers to material that can originate from post-consumer
sources such as domestic, distribution, retail, industrial, and
demolition. "Post-consumer fibers" means fibers obtained from
consumer products that have been discarded for disposal or recovery
after having completed their intended uses and is intended to be a
subset of post consumer recycled materials. Post-consumer materials
may be obtained from the sorting of materials from a consumer or
manufacturer waste stream prior to disposal. This definition is
intended to include materials which are used to transport product
to a consumer, including, for example, corrugated cardboard
containers.
[0076] The terms "ring roll" or "ring rolling" refer to a process
using deformation members comprising counter rotating rolls,
intermeshing belts or intermeshing plates containing continuous
ridges and grooves where intermeshing ridges (or projections) and
grooves (or recesses) of deformation members engage and stretch a
web interposed therebetween. For ring rolling, the deformation
members can be arranged to stretch the web in the cross machine
direction or the machine direction depending on the orientation of
the ridges and grooves.
[0077] The term "rotary knife aperturing" (RKA) refers to a process
and apparatus using intermeshing deformation members similar to
those described herein with respect to SELF or micro-SELF
deformation members. The RKA process differs from SELF or
micro-SELF in that the relatively flat, elongated teeth of a SELF
or micro-SELF deformation member have been modified to be pyramid
shaped, elongated with at least six sides, the sides being
substantially triangular and tapered to a point at the distal end.
The teeth can be sharpened to cut through as well as deform a web
to produce an apertured web, or in some cases, a
three-dimensionally apertured web, as disclosed in U.S. Patent
Application Publication Nos. US 2005/0064136A1, US 2006/0087053A1,
and US 2005/021753. In other respects such as tooth height, tooth
spacing, pitch, depth of engagement, and other processing
parameters, RKA and the RKA apparatus can be the same as described
herein with respect to SELF or micro-SELF.
[0078] The terms "SELF" or "SELF'ing", refer to Procter &
Gamble technology in which SELF stands for Structural Elastic Like
Film. While the process was originally developed for deforming
polymer film to have beneficial structural characteristics, it has
been found that the SELF'ing process can be used to produce
beneficial structures in other materials. Processes, apparatuses,
and patterns produced via SELF are illustrated and described in
U.S. Pat. Nos. 5,518,801; 5,691,035; 5,723,087; 5,891,544;
5,916,663; 6,027,483; and 7,527,615 B2.
[0079] The term "tuft", as used herein, refers to a particular type
of protrusion that may be formed in a nonwoven web. Tufts typically
have a tunnel-like configuration, and in some cases may be open at
one or both of their ends.
[0080] The term "upper" refers to absorbent members, such as
layers, that are nearer to the wearer of the absorbent article
during use, i.e. towards the topsheet of an absorbent article;
conversely, the term "lower" refers to absorbent members that are
further away from the wearer of the absorbent article towards the
backsheet. The term "laterally" corresponds to direction of the
shorter dimension of the article, which generally during use
corresponds to a left-to-right orientation of the wearer.
"Longitudinally" then refers to the direction perpendicular to the
lateral one, but not corresponding to the thickness direction.
[0081] The term "Z-dimension" refers to the dimension orthogonal to
the length and width of the web or article. The Z-dimension usually
corresponds to the thickness of the web or article. As used herein,
the term "X-Y dimension" refers to the plane orthogonal to the
thickness of the web or article. The X-Y dimension usually
corresponds to the length and width, respectively, of the web or
article.
I. Deformed Web Materials.
[0082] The present inventions are directed to deformed web
materials and methods and apparatuses for deforming a web. Methods
and apparatuses are disclosed that are capable of forming new
structures in webs that provide the webs with additional
properties. It should be understood that while the term "deformed
web materials" is utilized herein, the object is to create
components, such as absorbent members (or non-absorbent
components), for absorbent articles from such deformed web
materials. In such cases, the deformed web materials will be cut
into individual components for absorbent articles. The deformed web
materials can also be used in products other than absorbent
articles including, but not limited to packaging materials and
trash bags.
[0083] Structures can be provided in webs and the components formed
therefrom which are not possible to produce with current methods
and tooling (forming components). Such structures include features
extending out of the plane of the web on both sides of the web,
and/or features that are intermixed between other features. The web
can, in some cases, also be provided with features that are more
closely spaced than is possible with conventional tooling. In the
case of webs used in absorbent articles, such new structures may
include those that provide a single portion of the web with dual,
or more, properties (such as improved softness, fluid handling, or
other properties) in a predetermined portion of the web. The
apparatuses and processes can allow a web to be deformed multiple
times while maintaining control over the registration of the
deformations in the web. That is, the location/registration of the
web may be controlled in the machine direction and in the
cross-machine direction from the time the web is fed into the first
forming nip to the time it exits the last forming nip so
deformations made in the downstream nips occur in a controlled
location relative to deformations made in previous nips.
[0084] The web (or "precursor web") that will be deformed can
comprise any suitable deformable material, such as a woven,
nonwoven, film, combination, or laminate of any of the foregoing
materials. As used herein, the term "nonwoven web" refers to a web
having a structure of individual fibers or threads which are
interlaid, but not in a repeating pattern as in a woven or knitted
fabric, which do not typically have randomly oriented fibers.
Nonwoven webs or fabrics have been formed from many processes, such
as, for example, meltblowing, spunbonding, hydroentangling,
airlaid, wetlaid, through-air-dried paper making processes, and
bonded carded web processes, including carded thermal bonding. The
woven, nonwoven, film, combination, or laminate can be made of any
suitable materials including, but not limited to natural materials,
synthetic materials, and combinations thereof. Suitable natural
materials include, but are not limited to cellulose, cotton
linters, bagasse, wool fibers, silk fibers, etc. In some
embodiments, the web materials may be substantially free of
cellulose, and/or exclude paper materials. In other embodiments,
the methods described herein may be performed on
cellulose-containing precursor materials. Suitable synthetic
materials include, but are not limited to rayon and polymeric
materials. Suitable polymeric materials include, but are not
limited to: polyethylene, polyester, polyethylene terephthalate
(PET), and polypropylene. Any of the materials described above may
comprise post-consumer recycled material.
[0085] In one non-limiting embodiment, the deformed web material
comprises a web having discrete deformations formed therein. The
web has a first surface and a second surface. The web comprises: a)
substantially undeformed first regions, the undeformed regions
having surfaces that correspond to the first and second surfaces of
the web prior to the formation of deformations therein; b) a
plurality of spaced apart first formed features (or "first
features") in first locations comprising features that can
comprise: portions of the web material with apertures therein;
protrusions; and depressed areas (or "depressions"); and c) a
plurality of spaced apart second formed features (or "second
features") in second locations comprising features that can
comprise:
[0086] portions of the web material with apertures therein;
protrusions; and depressed areas (or "depressions"). In some
embodiments, the first features and/or the second features may be
selected from the group consisting of one or more of the foregoing
types of features. The second features may be of a different type
and/or have different properties or characteristics than the first
features, and the second features may be intermixed with the first
features. In some embodiments, all of the adjacent features, or all
of closest features, may be of a different type and/or have
different properties. In some embodiments, at least four of the
closest eight features in any direction to a given feature may be
of a different type and/or have different properties. The web
material may further comprise third, fourth or more formed
features. The third, fourth, or more features may comprise any of
the types of features or have any of the properties described
herein, and may differ from the first and second features in any
such aspects.
[0087] In certain embodiments, it may be possible to densely pack
multiple features within a relatively small area. For example, the
center-to-center spacing in any direction between a first feature
and a second feature may be less than or equal to about 20 mm,
alternatively 10 mm, 5 mm, 3 mm, 2 mm, or 1 mm, or lie in any range
between two of these numbers. The total number of features in an
area that measures 1 square inch (645 mm.sup.2) may be greater than
or equal to 4, 25, 100, 250, 500, or 645, or lie in any range
between two of these numbers. The number of first features in one
square inch may be the same or different from the number of the
second features in that same area. The number of features in a one
inch square area can be determined by marking a square area on the
material that measures 1 inch (25.4 mm) by 1 inch with a fine tip
pen or marker and counting the number of first, second, third, etc.
features that lie fully or partially within and on the boundary of
the 1 inch square. A low power microscope or other magnifying aid
can be used to aid visibility of the features in the material if
needed. The ratio of the number of first features to the number of
second features may be between 0.0016 and 155. When the number of
first features is the same as the number of second features, the
ratio will be 1. For embodiments related to a web comprising a
film, the ratio of the number of first features to the number of
second features may be between 0.125 and 8. Note, in cases where
there are third, fourth or more different types of features, these
ratios would apply to all paired combinations of features.
[0088] The first features and second features may be of any
suitable size. Typically, either the first features or the second
features will be macroscopic. In some embodiments, the first
features and the second features will both be macroscopic. The plan
view area of the individual features may, in some embodiments of
the web, be greater than or equal to about 0.5 mm.sup.2, 1
mm.sup.2, 5 mm.sup.2, 10 mm.sup.2, or 15 mm.sup.2, or lie in any
range between two of these numbers The methods described herein
can, however, be used to create first features and/or second
features that are microscopic which have plan view areas less than
0.5 mm.sup.2.
[0089] The first features and second features may be of any
suitable configuration. The features may be continuous and/or
discrete. Suitable configurations for the features include, but are
not limited to: ridges (continuous protrusions) and grooves
(continuous depressions); tufts; columnar shapes; dome-shapes,
tent-shapes, volcano-shapes; features having plan view
configurations including circular, oval, hour-glass shaped, star
shaped, polygonal, polygonal with rounded corners, and the like,
and combinations thereof. Polygonal shapes include, but are not
limited to rectangular (inclusive of square), triangular,
hexagonal, or trapezoidal. In some embodiments, the first and/or
second features may exclude one or more of the configurations
listed above.
[0090] The first features and the second features may differ from
each other in terms of one or more of the following properties:
type, shape, size, aspect ratio, edge-to-edge spacing, height or
depth, density, color, surface treatment (e.g., lotion, etc.),
number of web layers within the features, and orientation
(protruding from different sides of the web). The term "type", as
used herein, refers to whether the feature is an aperture (a two
dimensional aperture, or a three dimensional aperture), a
protrusion (a tuft, or other kind of protrusion), or a depression.
Two features will be considered to be different in type if one
feature comprises one of these features listed (for example, a two
dimensional aperture), and the other feature comprises another one
of the listed features (for example, a three dimensional aperture).
When the features are described as differing from each other in one
of more of the properties listed above, it is meant to include
those differences other than minor differences that are the result
of variations within manufacturing tolerances. It should also be
understood that although the web material may have discrete thermal
or adhesive bond sites therein, in some embodiments the features of
interest imparted by this process herein do not include such bond
sites.
[0091] The various types of deformed webs will be shown in
conjunction with the descriptions of the apparatuses and methods
used to form the same. These webs can be cut to form various
components of products such as absorbent articles (such as
topsheets, backsheets, acquisition layers, absorbent cores),
packaging (such as flow wrap, shrink wrap, and polybags), trash
bags, food wrap, wipes, facial tissue, toilet tissue, paper towels,
and the like.
II. Apparatuses for Deforming Web Materials.
[0092] Prior art approaches are not suitable for creating
well-defined inter-mixed features with controlled placement of the
features. Therefore, it is desirable to design a process that
enables better independent control over the formation of two or
more sets of features. Two approaches for achieving better
independent control over the formation of each set of features are
provided here. One approach utilizes a single nip with two rolls
comprising discrete male forming elements wherein at least one roll
comprises two or more raised ridges. A second approach comprises a
multi-hit (multi-nip) configuration that enables controlled
placement and orientation of multiple sets of features. Each of
these approaches may enable independent control over the formation
of each set of features and better pattern conformation of the web
to the roll such that the desired size and/or shape of the feature
is achieved.
[0093] The mechanical deformation process can be carried out on any
suitable apparatus that may comprise any suitable type(s) of
forming structure. Suitable types of forming structures include,
but are not limited to: a pair of rolls that define a nip
therebetween; pairs of plates; belts, etc. Using an apparatus with
rolls can be beneficial in the case of continuous processes,
particularly those in which the speed of the process is of
interest. Although the apparatuses will be described herein for
convenience primarily in terms of rolls, it should be understood
that the description will be applicable to forming structures that
have any other suitable configurations.
[0094] To assist in understanding the present inventions, several
prior art apparatuses are shown. FIG. 1 shows one embodiment of a
prior art apparatus 20 for deforming a web material. The apparatus
shown in FIG. 1 will be referred to as a "paired roll arrangement".
In this apparatus, a web material 10 is fed through a first nip N
between a first pair 22 of stacked rolls comprising rolls 22A and
22B. Downstream from the first pair 22 of stacked rolls, the web is
fed through a second nip N between a second pair 24 of stacked
rolls comprising rolls 24A and 24B. The web material 10 has a first
surface or side 10A and a second surface or side 10B. Typically,
such an apparatus is used to form continuous deformations into a
web. Applicants have considered utilizing such an apparatus to form
discrete deformations into the web 10 at each nip. However, such an
apparatus is subject to difficulties in registering or aligning
deformations that may be made at the second nip with deformations
that are made at the first nip. These difficulties are caused at
least in part by the fact that there is a free span of web
material, S, between the first and second nips that is not
maintained in contact with any rolls. This results in loss of
precision in control over the portion of the web that will be
deformed at the second nip. This is particularly the case with more
flexible or lower modulus materials, as are often found in
disposable products that can change dimensions in the free span
between successive nips.
[0095] FIG. 2 shows another prior art apparatus for deforming a web
material. The apparatus 30 shown in FIG. 2 will be referred to as a
"planetary" or "satellite" roll arrangement. In this apparatus,
there is a "sun" or central roll 32, and one or more satellite
rolls 34, 36, and 38, that form nips N with the central roll 32. It
should be understood, however, that although the apparatuses shown
in FIGS. 1 and 2 are known, there are variations of the same
disclosed herein that are not believed to be known, and it is
expressly not admitted that FIG. 1 or 2 disclose such variations.
The disadvantage of a conventional planetary roll arrangement is
that the downstream satellite rolls 36 and 38 can only deform the
web 10 on the same side as the first satellite roll 34. Thus, it
would not ordinarily be possible to form discrete deformations in
the web, some of which extend out from one surface of the web, and
some of which extend out from another surface of the web with
independent control of the deformation and placement of multiple
sets of features. Another disadvantage of a conventional planetary
roll arrangement is that satellite rolls 34, 36 and 38 are only
capable of deforming the web 10 in the recesses of the central
roll. Therefore, the spacing of the formed features is limited by
the spacing of the recesses on the central roll. Thus, it would not
be possible to form discrete deformations in the web that have a
smaller center-to-center spacing than the center-to-center spacing
of the recesses on the forming roll(s).
[0096] FIG. 3 shows another prior art apparatus for deforming a web
material, which is a variation of the apparatus shown in FIG. 2.
The apparatus has a central roll 42 and satellite rolls 44 and 48.
The apparatus 40 shown in FIG. 3 differs from the apparatus shown
in FIG. 2 in that at one place around the central roll 42, the web
material 10 is transferred from the surface of the central roll 42
to a roll 46 that is spaced away from the central roll 42 such that
this latter roll 46 does not form a nip with the central roll 42.
The apparatus shown in FIG. 3 will be referred to as a planetary or
satellite roll arrangement with a removable roll. The disadvantage
of a planetary or satellite roll arrangement with a removable roll
arrangement is that if deformations are being made in the web 10
after the web leaves the central roll 42 to wrap around the
removable roll 46, it is difficult to maintain control over the
registration of the deformations in the web due to the large free
spans of material, S, between the deformation nips.
[0097] Applicants have also considered using a single nip
comprising two rolls with discrete male forming elements to form
multiple set of discrete deformations into the web. The
disadvantage of this approach is that typically, one set of
features will be preferentially formed over the other, and the
second set of features may never be formed or will not result in
the desired feature size and/or shape. Without wishing to be bound
by any particular theory, it is believed that this is a result of
the material following the path of least resistance, which is
dependent upon the two mating roll patterns. In situations in which
the mating rolls are identical, a conventional single nip apparatus
will not produce the same structure that is created if the elements
are formed independently in separate nips. Prior art approaches do
not provide an apparatus that can create independent control of the
deformation and placement of multiple sets of features. Because of
the drawbacks associated with the above apparatuses, applicants
have developed improved configurations for the arrangement of the
rolls.
[0098] FIG. 4 shows one non-limiting embodiment of an apparatus
that can be used in the processes described herein. The apparatus
50 shown in FIG. 4 will be referred to as a "nested roll"
arrangement. In this apparatus 50, the rolls 52, 54, 56, 58, and 60
are arranged in an offset configuration when viewed from the side
(that is, the ends of the rolls). In this apparatus, at least one
roll, such as rolls 54, 58, and 60, are positioned in a gap between
two adjacent rolls. At least two of the rolls define two or more
nips N thereon with other rolls. For example, roll 58 forms two
nips--with rolls 52 and 54; and roll 54 forms two nips--with rolls
58 and 60. Typically, in a nested roll arrangement, there will be
at least four generally cylindrical rolls, and at least two of the
rolls will have forming elements thereon. More specifically, in a
nested configuration, the rolls each have an axis, A, and the rolls
are arranged so that if the rolls are viewed from one of their
circular sides, and lines B and C are drawn through the axes A of
at least two different pairs of said rolls (which pairs may have at
least one roll in common), will be non-parallel. As shown in FIG.
4, at least some of the lines B and C drawn through the axes of
adjacent pairs of rolls form an angle therebetween.
[0099] The nested roll arrangement may provide several advantages.
A nested roll arrangement provides more nips per total number of
rolls than some of the roll arrangements shown in FIGS. 1-3. The
nested roll arrangement maintains control of the web 10 for
registering deformations in the web since all portions along the
length of the web on at least one surface of the web may remain
substantially in contact with at least one of the rolls from the
point where the web enters the first forming nip to the location
where the web exits the last forming nip. When the web is described
as remaining substantially in contact with the rolls, the web may
contact the roll(s) only on the tips of the forming elements on the
roll, bridging between adjacent forming elements. A web containing
small free spans between adjacent forming elements would still be
considered to be in substantial contact with the rolls, as would a
roll arrangement in which there is an unsupported section of the
web or free span that is less than or equal to 2 cm in length. The
nested roll arrangement provides the ability to create deformations
in different cross-machine direction locations (or lanes) and on
different sides of a web. The nested roll arrangement also has a
smaller footprint on a manufacturing floor. The entire nested roll
arrangement shown in FIG. 4 could also be rotated 90.degree. so
that the rolls are stacked vertically, and the apparatus would
occupy even less space on a manufacturing floor.
[0100] FIG. 4A shows an alternative embodiment of a method and
nested roll apparatus 62 for deforming a web. The apparatus 62 is
similar to the apparatus shown in FIG. 4. However, in the
embodiment shown in FIG. 4A, a second web 12 is introduced at a nip
N2 downstream of the first nip N1. The methods described herein
contemplate that any number of additional webs may be fed into the
apparatuses at any nip downstream of the first nip. The additional
layers may be used to add webs having different chemical
compositions, formulations, aesthetics, conductive properties,
aromatic properties, and mechanical properties. The processes
described herein enable independent control of the features formed
in a multi-layer structure, providing additional control over the
function and aesthetics of the features. For example, this process
could provide the ability to create multi-layer structures where
the some features have more layers through their thickness than
other features.
[0101] The rolls used in the apparatuses and methods described
herein are typically generally cylindrical. The term "generally
cylindrical", as used herein, encompasses rolls that are not only
perfectly cylindrical, but also cylindrical rolls that may have
elements on their surface. The term "generally cylindrical" also
includes rolls that may have a step-down in diameter, such as on
the surface of the roll near the ends of the roll. The rolls are
also typically rigid (that is, substantially non-deformable). The
term "substantially non-deformable", as used herein, refers to
rolls having surfaces (and any elements thereon) that typically do
not deform or compress under the conditions used in carrying out
the processes described herein. The rolls can be made from any
suitable materials including, but not limited to steel, aluminum or
rigid plastic. The steel may be made of corrosion resistant and
wear resistant steel, such as stainless steel. The rolls may or may
not be heated. If heated, consideration of thermal expansion
effects must be accommodated according to well known practices to
one skilled in the art of thermo-mechanical processes.
[0102] The rolls used in the apparatuses and methods described
herein are used to mechanically deform portions of the web material
or materials. The mechanical deformation process may be used to
permanently deform portions of the web and form the types of
features in the web described above. The terms "mechanically
deform" and "mechanical deformation", as used herein, do not
include hydroforming processes. The features formed by the
processes described herein may be registered since the processes
described herein maintain control of the web, which may be in
substantially continuous contact with at least one of the rolls
(which serves as a metering surface) between the first nip through
which the web material passes until the material exits the last
nip.
[0103] The rolls may have any suitable type of elements on their
surface (or surface configuration). The surface of the individual
rolls may, depending on the desired type of mechanical deformation,
be provided with forming elements comprising: "male" elements such
as discrete projections, or continuous projections such as ridges;
"female" elements or recesses such as discrete or continuous voids
in the surface of the rolls; or any suitable combination thereof.
The female elements may have a bottom surface (which may be
referred to as depressions, cavities, or grooves), or they may be
in the form of apertures (through holes in the surface of the
rolls). In some embodiments, the forming elements on the components
(such as the rolls) of the forming structure may comprise the same
general type (that is, the opposing components may both have male
forming elements thereon, or combinations of male and female
elements).
[0104] The forming elements may have any suitable shape or
configuration. A given forming element can have the same plan view
length and width dimensions (such as a forming element with a
circular or square shaped plan view). Alternatively, the forming
element may have a length that is greater than its width (such as a
forming element with a rectangular plan view), in which case, the
forming element may have any suitable aspect ratio of its length to
its width. Suitable configurations for the forming elements
include, but are not limited to: ridges and grooves, teeth having a
triangular-shaped side view; columnar shapes; elements having plan
view configurations including circular, oval, hour-glass shaped,
star shaped, polygonal, and the like, and combinations thereof.
Polygonal shapes include, but are not limited to rectangular,
triangular, hexagonal, or trapezoidal. The forming elements can
have tips that are flat, rounded or sharp. In certain embodiments,
the shapes of the female elements may differ from the shapes of any
mating male forming elements. In certain embodiments, the female
forming elements can be configured to mate with one or more male
forming elements.
[0105] The forming elements can be of any suitable size and have
any suitable spacing. For instance, at least one forming element
for forming micro-textured webs has a center-to-center spacing of
less than about 800 microns with at least three, at least four, or
at least five of its adjacent forming elements as described in U.S.
patent application Ser. No. 13/094,477 entitled "Process for Making
a Micro-Textured Web", filed on the same date as the present
application. In some embodiments, at least 25%, at least 50%, at
least 75%, at least 95%, or all of the forming elements on a
forming structure have center-to-center spacings of less than about
800 microns with at least three, at least four, or at least five of
their adjacent forming elements 10. Other acceptable
center-to-center spacings are from about 30 microns to about 700
microns, from about 50 microns to about 600 microns, from about 100
microns to about 500 microns, or from about 150 microns to about
400 microns. The center-to-center spacings among adjacent forming
elements may be the same or different. The center-to-center spacing
of the forming elements may range from the scale used for such
micro-textured webs up to, or greater than, the examples of the
size of the center-to-center spacing of the larger forming elements
described herein. Suitable configurations for the forming
components include, but are not limited to: ring rolls; SELFing
rolls; Micro-SELFing rolls; and RKA rolls; male/female embossing
rolls; and the forming structures for forming the micro-textured
web in the patent application described above. Several such roll
surface configurations are described below.
[0106] FIG. 5 shows an embodiment in which the rolls 64 and 66 are
referred to herein as "ring rolls". The rolls 64 and 66, as in the
case of the rolls in the other apparatuses shown and described
herein, are carried on respective rotatable shafts having their
axes A of rotation disposed in a parallel relationship. In all of
the embodiments described herein, the rolls are non-contacting, and
axially-driven. In this embodiment, the surfaces of the rolls have
a plurality of alternating ridges 68 and grooves 70 extending
around the circumference of the rolls. In other embodiments, the
ridges and grooves may extend parallel to the axes A of the rolls.
One or more of such rolls can be used in the various embodiments of
the apparatuses described herein.
[0107] In the embodiment shown in FIG. 5, and the various other
embodiments described herein, the rolls may be meshing,
non-meshing, or at least partially intermeshing. The terms
"meshing" or "inter-meshing", as used herein, refer to arrangements
when the forming elements on one of the components of the forming
structure (e.g., roll) extend toward the surface of the other
forming structure and the forming elements have portions that
extend between and below an imaginary plane drawn though the tips
of the forming elements on the surface of the other forming
structure. The term "non-meshing", as used herein, refers to
arrangements when the forming elements on one of the components of
the forming structure (e.g., roll) extend toward the surface of the
other forming structure, but do not have portions that extend below
an imaginary plane drawn though the tips of the forming elements on
the surface of the other forming structure. The term "partially
intermeshing", as used herein, refers to arrangements when the
forming elements on one of the components of the forming structure
(e.g., roll) extend toward the surface of the other forming
structure and some of the forming elements on the surface of the
first roll have portions that extend between and below an imaginary
plane drawn though the tips of the forming elements on the surface
of the other forming structure, and some of the elements on the
surface of the first roll do not extend below an imaginary plane
drawn though the tips of the forming elements on the surface of the
other forming structure.
[0108] As shown in FIG. 5, the rolls typically rotate in opposite
directions (that is, the rolls are counter-rotating). This is also
the case for the other embodiments described herein. The rolls may
rotate at substantially the same speed, or at different speeds. The
phrase "substantially the same speed", as used herein, means that
there is less than 0.3% difference in the speed. The speed of the
rolls is measured in terms of surface or peripheral speed.
Typically, when the web comprises polymeric materials, the rolls
will rotate at substantially the same speed. If the web comprises
cellulosic materials, the rolls may rotate at different speeds. The
rolls may rotate at different surface speeds by rotating the rolls
at different axial speeds, or by using rolls that have different
diameters that rotate at the same axial speeds. The rolls may
rotate at substantially the same speed as the speed at which the
web is fed through the nip between the rolls; or, they may rotate
at a greater speed than the speed at which the web is fed through
the nip between the rolls. In cases where the rolls rotate at
different speeds, there can be any suitable difference in surface
or peripheral speeds between the rolls such as from greater than or
equal to 0.3% up to 100%. One suitable range is between 1-10%. It
is generally desirable for the rolls to rotate at speeds which
maintain the integrity of the web (that is, not shred the web).
[0109] FIG. 6 shows an alternative roll embodiment in which the top
roll 72 is a ring roll having circumferential ridges 68 and grooves
70, and the bottom roll 74 is one of The Procter & Gamble
Company's "SELF" or "SELFing" rolls. The forming elements on the
SELF rolls can be oriented in either the machine direction (MD) or
the cross-machine direction (CD). In this embodiment, the SELF roll
comprises a plurality of alternating circumferential ridges 76 and
grooves 78. The ridges 76 have spaced apart channels 80 formed
therein that are oriented parallel to the axis A of the roll. The
channels 80 form breaks in the ridges 76 that create discrete
forming elements or teeth 82 on the SELF roll 74. In the embodiment
shown in FIG. 6, the teeth 82 have their longer dimension oriented
in the machine direction (MD). The roll configuration shown in FIG.
6 will be referred to herein as a standard "CD SELF" roll since the
teeth are aligned in rows in the MD and CD, and in the usual SELF
process, the material being fed into the nip N having such a roll
would be stretched in the cross-machine direction (or "CD").
[0110] In other embodiments, which are described in the SELF
patents that are incorporated by reference herein, the SELF roll
can comprise a machine direction, or "MD SELF" roll. Such a roll
will have alternating ridges and grooves that are oriented parallel
to the axis A of the roll. The ridges in such a roll have spaced
apart channels formed therein that are oriented around the
circumference of the roll. The channels form breaks in the ridges
to form discrete forming elements or teeth on the MD SELF roll. In
the case of MD SELF rolls, the teeth have their longer dimension
oriented in the cross-machine direction (CD).
[0111] FIG. 6A is another embodiment of a roll suitable for use in
the apparatuses described herein. In this embodiment, the roll 90
comprises a variation of one of The Procter & Gamble Company's
CD SELF technology rolls. As shown in FIG. 6A, the surface of the
roll has a plurality of spaced apart teeth 100. The teeth 100 are
arranged in a staggered pattern. More specifically, the teeth 100
are arranged in a plurality of circumferentially-extending,
axially-spaced rows, such as 102A and 102B, around the roll. But
for the spacing TD between the teeth in each row, the teeth in each
roll would form a plurality of circumferentially-extending,
axially-spaced alternating ridges and grooved regions. The tooth
length TL and machine direction (MD) spacing TD can be defined such
that the teeth in adjacent rows 102A and 102B either overlap or do
not appear to overlap when the rolls are viewed from one of their
ends. In the embodiment shown, the teeth 100 in adjacent rows are
circumferentially offset by a distance of 0.5x (where "x" is equal
to the tooth length TL plus the MD spacing TD between teeth in a
given row). In other words, the leading edges LE of adjacent teeth
in adjacent rows will be offset in the MD by 0.5x. The rolls shown
in FIG. 6A can be made in any suitable manner, such as by first
cutting the ridges and grooves into the roll, then helically
cutting the teeth 100 into the surface of the roll with each
helical cut being continuous. If desired, the tooth profile (in
particular, the leading and trailing edges) can be modified by
using a plunge cut.
[0112] The roll 90 can be aligned with an opposing roll which has
ridges and grooves therein so that the rows of teeth in one roll
align with the grooved regions between the teeth in the opposing
roll. The advantage of using CD SELF rolls in the methods described
herein is that registration of multiple rolls to provide multiple
hits (impacts within multiple nips) is much easier in that it is
only necessary to register the toothed regions (that is, to align
the toothed regions with the grooved regions on the opposing roll)
in the cross-machine direction, and it is not necessary to phase or
register the toothed regions in the MD. The staggered tooth pattern
allows the web 10 to be mechanically impacted to form features in a
staggered pattern.
[0113] FIG. 6B shows in cross section a portion of the intermeshing
rolls 72 and 74 shown in FIG. 6 including teeth 82 which appear as
ridges 76 and grooves 78 between the teeth 82. The teeth can have a
triangular or inverted V-shape when viewed in cross-section. The
vertices of teeth are outermost with respect to the surface of the
rolls. As shown, teeth 82 that have a tooth height TH, a tooth
length TL (FIG. 6), and a tooth-to-tooth spacing (or ridge-to-ridge
spacing) referred to as the pitch P. For staggered rolls, the pitch
is equal to the spacing between adjacent rows of forming elements.
The tooth length TL in such embodiments is a circumferential
measurement. The outermost tips of the teeth have sides that are
preferably rounded to avoid cuts or tears in the precursor
material. The size and shape of the tooth tip may be specified via
the tip radius TR. The leading and trailing ends of the teeth may
have a radius as well, or the teeth may form a right angle (and
have no radius). As shown, the ridges 68 of one roll extend
partially into the grooves 78 of the opposed roll to define a
"depth of engagement" (DOE) E, which is a measure of the level of
intermeshing of rolls 72 and 74. The depth of engagement can be
zero, positive for meshing rolls, or negative for non-meshing
rolls. The depth of engagement E, tooth height TH, tooth length TL,
tooth spacing TD, tip radius TR, and pitch P can be varied as
desired depending on the properties of precursor web 10 and the
desired characteristics of the formed web 20.
[0114] The teeth can have any suitable dimensions. In certain
embodiments of the SELF rolls, the teeth 100 can have a length TL
ranging from about 0.5 mm (0.020 inches) to about 13 mm (0.512
inches) and a spacing TD from about 0.5 mm to about 13 mm, a tooth
height TH ranging from about 0.5 mm to about 17 mm (0.669 inches),
a tooth tip radius TR ranging from about 0.05 mm (0.002 inches) to
about 0.5 mm (0.020 inches), and a pitch P between about 1 mm
(0.040 inches) and 10 mm (0.400 inches). The depth of engagement E
can be from about -1 mm to about 16 mm (up to a maximum approaching
the tooth height TH). Of course, E, P, TH, TD, TL, and TR can each
be varied independently of each other to achieve the desired
properties in the web. Another property describing the teeth is
their side wall angle. The side wall angle is the angle the longer
sides of the teeth make relative to an imaginary vertical line
extending outward from the central axis of the roll through the
center of the teeth. Any radius at the tips of the teeth is
ignored. Typically, the side wall angle of the teeth is defined
such that when the rolls are inter-meshing, there is sufficient
clearance for the web and the web is not sheared (where portions of
the web forced to slip relative to other portions) or pinched by
the tooling. However, for some materials, such as those comprising
cellulose fibers, it can be advantageous to have smaller clearances
and induce shear in the material. Typically, the side wall angle
will range from between about 3 to about 15 degrees. The leading
and trailing ends of the teeth are typically squared off and have a
vertical side wall from the base to the tip of the tooth.
[0115] FIG. 6C shows an alternative roll 92 embodiment which is
referred to herein as an "MD staggered SELF" roll in which the
teeth 100 are oriented with their longer dimension oriented in the
CD and are staggered. The roll 92 has circumferentially extending
channels 94 formed between the teeth.
[0116] FIG. 7 shows an alternative roll embodiment which the top
roll is a ring roll, and the bottom roll is referred to herein as a
Rotary Knife Aperturing (or "RKA") roll. As shown in FIG. 7, the
rolls comprise a pair of counter-rotating, intermeshing rolls,
wherein the top roll 72 comprises circumferentially-extending
ridges 68 and grooves 70, and the bottom roll 104 comprises pyramid
shaped teeth 110 with at least six sides, the sides being
substantially triangular and being tapered from a base to a tip.
The teeth 110 are arranged in spaced apart circumferential rows
with grooves 112 therebetween. The teeth 110 are joined to the
bottom roll 104 at the base, and the base of the tooth has a
cross-sectional length dimension greater than a cross-sectional
width dimension. Typically, apertures are formed in the web
material 10 as the teeth 110 on the RKA roll 104 intermesh with
grooves 70 on the other roll 72. With respect to tooth height,
tooth spacing, pitch, depth of engagement, and other processing
parameters, RKA and the RKA apparatus can be the same as described
herein with respect to SELF or micro-SELF. RKA rolls are described
in greater detail in U.S. Patent Application Publication No. US
2006/0087053 A1. A variation of such an RKA roll is shown in FIGS.
14 to 14C.
[0117] FIG. 8 shows a portion of the nip between a pair of rolls
suitable for use in the apparatuses described herein in which the
rolls are "male/female embossing" rolls. As shown in FIG. 8,
male/female embossing apparatus comprises at least a first and a
second patterned roll 114 and 116. The first patterned roll 114 has
a male embossing pattern, comprising one or more projections 118
which may be discrete elements (e.g., dot and/or line) embossing
elements. The second patterned roll 116 has a female embossing
pattern comprising one or more recesses 120, which may be discrete
(e.g., dot and/or line configured recesses), into which one or more
of the projections of the first patterned roll mesh. The rolls may
have matched or unmatched patterns. The elements on the rolls can
be of any suitable size and shape. In one non-limiting embodiment
detailed in U.S. Pat. No. 6,846,172 B2, Vaughn, the embossing rolls
may have unmatched embossing patterns, which were engraved
independently from each other. The rolls 114 and 116 in such an
embodiment have enlarged sidewall clearances between adjacent,
inter-engaged projections 118 and recesses 120 of the embossing
patterns. The sidewall clearances can range from about 0.002 inch
(about 0.050 mm) to about 0.050 inch (about 1.27 mm). The width of
the projections 118 can be greater than about 0.002 inch (about
0.050 mm).
[0118] FIG. 9 shows an alternative non-limiting embodiment in which
the surfaces of the rolls 124 and 126 comprise forming elements
suitable for forming the micro-textured web in the patent
application described above entitled "Process for Making a
Micro-Textured Web". The rolls shown in FIG. 9 comprise a roll 124
comprising male forming elements, protrusions or projections 128,
and a roll 126 comprising female forming elements, such as discrete
and/or continuous voids 130, in the surface of the roll 126. The
projections 128 have center-to-center spacings of less than about
800 microns with at least three, at least four, or at least five of
its adjacent forming elements. As shown in FIG. 9, the shapes of
the female elements 130 may differ from the shapes of the mating
male elements 128. FIG. 9 also shows that the female elements 130
can be configured to mate with more than one male element 128.
[0119] FIG. 9A shows a portion of a forming structure having a
combination of various forming elements. As illustrated in FIG. 9A
the forming elements of either or both of the first and second
forming structures can include projections such as protrusions 128
or recesses such as voids 130 selected from discrete protrusions
128 (which can take the form of pillars 132), discrete voids 130
(which can take the form of apertures 134 or depressions 136),
continuous voids 138, grooves, ridges, or a combination thereof.
The forming structures can further include lands 140 completely
surrounding the forming elements.
[0120] The various types of rolls described above (as well as other
types of rolls having forming elements thereon) may be combined in
any suitable combinations in the different apparatuses described
herein to deform a web of material in a particular manner. The
apparatuses may comprise several rolls comprising a single type of
roll described above, or any suitable combinations of two or more
different types of rolls. The web 10 can be fed through any
suitable number of mechanical deformation processes. The number of
mechanical deformation nips to which the precursor web is subjected
can range from one to between 2 and 100, or more, nips.
[0121] There can also be variations of the arrangements of rolls in
the different apparatuses of interest herein. In the embodiment
shown in FIG. 4, the rolls are arranged so that when a web is fed
into nips between the rolls, the web 10 will wrap less than
180.degree. around one or more of the rolls. In the variation of
this embodiment shown in FIG. 10, the web is fed into the apparatus
so that the web 10 will wrap greater than or equal to 180.degree.
around one or more of the rolls.
[0122] FIG. 11 shows another embodiment of an apparatus that can be
used in carrying out the methods described herein. The apparatus
shown in FIG. 11 is a hybrid of the nested roll arrangement and the
prior art paired roll arrangement. In this embodiment, the
apparatus includes rolls 144 arranged in a hybrid arrangement such
that there are multiple three to four nested roll clusters 146 that
can then be offset relative to each other in the cross-machine
direction.
[0123] FIG. 12 shows another embodiment of an apparatus that can be
used in carrying out the methods described herein. The apparatus
shown in FIG. 12 will be referred to as a "nested closed loop" roll
arrangement. In this apparatus, there are at least four rolls and
the rolls are arranged with their peripheries adjacent to each
other in the configuration of a closed loop. The web 10 wraps
around the peripheries of the rolls in an alternating configuration
with a portion of the web 10 on a portion of a roll that lies
inside the periphery of the closed loop, followed by wrapping the
web 10 around the next roll about a portion of the roll that lies
on the outside of the periphery of the closed loop. In this
embodiment, the total number of nips N formed by the rolls is equal
to the number of rolls.
[0124] FIG. 13 shows another embodiment of an apparatus 150 that
can be used in carrying out the methods described herein. The
apparatus 150 shown in FIG. 13 will be referred to as a "nested
with shared bank" roll arrangement. In this apparatus, there are at
least six rolls designated generally by reference number 152. The
rolls are arranged in at least three pairs of rolls comprising a
first pair 154 comprising rolls 154A and 154B, a second pair 156
comprising rolls 156A and 156B, and a third pair 158 comprising
rolls 158A and 158B. In FIG. 13, additional pairs of rolls are
shown. The rolls 156A and 156B in the second pair of rolls form
nips N with the rolls in both the first and third pairs of rolls
154 and 158. In this embodiment, some of the rolls form three or
more nips (up to four nips). In addition, as can be seen in FIG.
13, in the case of at least one roll such as roll 156B, the web 10
passes adjacent to the roll, leaves the roll, and then returns to
contact the roll again. In this embodiment, when there are six
rolls, the total number of nips N formed by the rolls is equal to
the number of rolls. In variations of this embodiment comprising
seven or more rolls, the total number of nips N formed by the rolls
can be greater than or equal to the number of rolls. For example,
in FIG. 13, there are fourteen nips N formed by only twelve
rolls.
III. Methods for Deforming Web Materials and Deformed Web Materials
Formed Thereby.
[0125] The following figures show non-limiting examples of specific
roll arrangements, and the deformed web materials that can be
formed thereby.
[0126] A. Methods Employing a Roll with Forming Elements Extending
from a Raised Ridge.
[0127] FIG. 14 shows an example of an apparatus 160 that comprises
a single pair of rolls that form a single nip N therebetween. The
rolls are configured for deforming a web with at least two sets of
deformations that are oriented in different directions relative to
the surfaces of the web. This can be accomplished by providing one
of the rolls 162 with a plurality of ridges 164 and grooves 166
extending around the circumference of the roll and a plurality of
first spaced apart forming elements 168 extending outwardly from
the top surface of the ridges 164, and providing a second roll 170
with a plurality of second forming elements 172 on its surface in
which the tips of the second forming elements extend inward toward
the axis of the first roll to a depth beyond the top of at least
some of the ridges 164 on the first roll 162.
[0128] The top roll 162 in the apparatus shown in FIG. 14 can
comprise any suitable type of roll that meets the criteria set out
above. In the embodiment shown in FIG. 14, the top roll 162 is a
variation of the RKA roll shown in FIG. 7. This particular
variation will be referred to herein as a "raised ridge RKA roll".
As shown in FIG. 14, the top roll 162 has a plurality of ridges 164
and grooves 166 extending around the circumference of the roll on
the surface of the roll. As shown in FIG. 14A, the ridges 164 have
a top surface 165 and the grooves 166 have a bottom surface 167.
The ridge height is defined as the distance between the top surface
of the ridge 165 and the bottom surface 167 of the grooves 166. The
tooth height is defined as the distance between the tip 174 of the
forming element 168 and the bottom surface 167 of the grooves 166.
In this embodiment, the distance between the top surfaces 165 of
the ridges 164 and the bottom surfaces 167 of the grooves 166 is
substantially the same around the circumference of the roll. The
ridge height depends on the amount of deformation that is required
to form the second set of features. The ridge height is typically
at least about 25% up to less than about 95% of the tooth height.
The roll 162 further comprises a plurality of spaced apart first
forming elements in the form of teeth 168 extending outwardly from
the top surface of the ridges 164, as shown in greater detail in
FIGS. 14A and 14C. The teeth 168 taper from the base where they are
joined to the top surface 165 of the ridges 164 to a pointed tip.
As shown in FIG. 14A, the configuration of the roll 162 is such
that the top surface 165 of the ridges 164 are disposed between the
tips 174 of the teeth 168 and the bottom surface 167 of the grooves
166, directionally relative to the axis A of the roll.
[0129] The bottom roll 170 in the apparatus shown in FIG. 14 can
comprise any suitable type of roll that meets the criteria set out
above. The bottom or second roll 170 in FIG. 14 should, thus,
comprise a roll with discrete second forming elements 172 thereon
in which the tips of these second forming elements 172 extend
inward toward the axis of the first roll 162 to a depth beyond the
top 165 of at least some of the ridges 164 on the first roll, top
roll 162. The bottom roll 170 can, for example, comprise a standard
CD SELF roll (as in FIG. 6), a staggered CD SELF roll (as in FIG.
6A), an RKA roll (as in FIG. 7), another raised ridge RKA roll, or
a raised ridge SELF roll (as in FIG. 14B). In the particular
embodiment shown in FIG. 14, the bottom roll 170 comprises a
staggered CD SELF roll such as the roll shown in FIG. 6A. Of
course, the positions of the rolls shown in FIG. 14 can be
reversed, or be arranged in any other suitable orientation (such as
side-by-side) so long as they form a nip therebetween.
[0130] The web 10, in its initial state, can be thought of as being
comprised entirely of undeformed regions. When the web 10 is fed
into the nip N between the rolls shown in FIG. 14, the web is
deformed: (i) by the first forming elements 168 of the top roll 162
to form a plurality of spaced apart first features in first
locations; and (ii) by the second forming elements 172 of the
bottom roll 170 in different locations than the first locations to
form a plurality of spaced apart second features in second
locations such that the second features are distributed between the
first features. As the first set of features is formed, the raised
ridge supports the web so that the second set of features can be
formed in the opposite direction. If the raised ridge is not
present, the set of features that is easiest to form (such as
apertures in this example) will be formed first, and the second set
of features will never be formed, or if the second features are
formed, they will not be formed in the desired feature size and/or
shape.
[0131] FIG. 15 shows an example of a web 10 that can be made by a
variation of the apparatus shown in FIG. 14. The variation of the
apparatus used to form the web shown in FIG. 15 comprises an RKA
roll for the upper roll 162 as shown in FIG. 14, but with a
standard (non-staggered tooth) pattern, and the lower roll 170 is
replaced with a standard (non-staggered) CD SELF roll such as shown
in roll 74 in FIG. 6. As used herein, the term "standard" means
that the forming elements on a single roll are aligned in rows in
the machine direction and the cross-machine direction. The rolls
162 and 170 are aligned or phased in the machine direction such
that the forming elements 172 on the SELF roll align with the
ridges 164 on the RKA roll. As the teeth 168 on the RKA roll 162
penetrate the web 10, the ridges 164 between the teeth 168 on the
RKA roll support the web 10 such that the SELF teeth 172 can
penetrate the web 10 and simultaneously form elements in the
opposite direction.
[0132] In the example of the web shown in FIG. 15, the web has a
first surface 10A and a second surface 10B and discrete
deformations formed therein. The web 10 comprises: substantially
undeformed regions 180, which correspond to the first and second
surfaces 10A and 10B of the web. In FIG. 15, web 10 further
comprises a plurality of spaced apart first features such as
apertures 182, and a plurality of spaced apart second features such
as tufts 184. The apertures 182 are pushed out of the plane of the
web 10 in one direction (downward as viewed in FIG. 15), and the
tufts 184 are pushed out of the plane of the web 10 in the opposite
direction. As shown in FIG. 15, the apertures 182 are aligned in
rows in the MD and the CD. The tufts 184 are also aligned in rows
in the MD and CD. The rows of tufts 184 are, however, aligned
between the rows of apertures 182 in the MD and the CD, with the
rows of tufts 184 being offset in the CD such that they are
separated from the adjacent rows of apertures 182 by a distance of
up to one half of the pitch between the apertures 182 in the
cross-machine direction (CD).
[0133] FIG. 15 shows one example of a combination of features that
can comprise the first and second formed features. Although
combinations of apertures and tufts are frequently shown in the
drawings, it should be understood, however, that in all of the
embodiments described herein the first features and second features
are not limited to apertures and tufts, and that the first features
and second features can, depending on the configuration of the
forming elements, comprise any other suitable combinations and
configurations of features. The present invention is, thus, not
limited to the combination of features shown in FIG. 15 and the
figures that follow, and is intended to cover all possible
combinations and configurations of the features described herein.
In addition, the present invention is not limited to forming two
features in a web in first and second locations. It is also
contemplated that additional features can be formed into the web in
third, fourth, fifth, or more, locations.
[0134] The configuration of the rolls shown in FIG. 14 may provide
a number of advantages. The rolls can, within a single nip, form a
web that has intermixed features oriented in multiple directions
(for example, apertures 182 may be pushed out of the plane of the
web in one direction, and tufts 184 may be pushed out of the plane
of the web in the opposite direction). The features may be
distributed within the web so that they are consistently less than
one pitch apart. Thus, if two different types of features are
formed, the spacing between dissimilar elements may be less than
spacing between like elements.
[0135] Various alternative embodiments of the raised ridge rolls
are possible. For example, FIG. 14D shows an alternative embodiment
of the raised ridge RKA roll 162A in which the height, H, of the
ridges 164 varies between at least some of the teeth 168. In such a
case, the top surface 165 of at least one ridge 164 between a pair
of forming elements 168 will have a height H1 that is at least 20%
greater than the height H2 of another ridge 164 between another
pair of forming elements 168. This roll 162A could be used in a
process such as that shown in FIG. 14 in place of the raised ridge
RKA roll 162. FIG. 14B shows yet another alternative type of roll
that could be used, which will be referred to herein as a "raised
ridge SELF roll" 162B. As shown in FIG. 14B, this roll 162B has
teeth 168 that are configured to form ridges rather than
points.
[0136] A variation of the apparatus shown in FIG. 14 can utilize an
additional roll and a two step process. The apparatus used for such
a variation can resemble the planetary roll arrangement shown in
FIG. 2. This apparatus need only comprise a central roll 32 and a
first satellite roll 34 and a second satellite roll 36. The
apparatus differs from known planetary roll arrangements in that it
utilizes the new roll configurations described herein. The
objective of such a modified planetary roll arrangement is to form
two sets of deformations in the web, and to further deform one of
the sets of deformations at one of the nips. In such an apparatus,
the central roll 32 can comprise a raised ridge roll, such as a
raised ridge SELF roll in FIG. 14B or a raised ridge RKA roll, such
as rolls 162 or 162A. One of the satellite rolls 34 or 36 comprises
a roll having a plurality of discontinuous ridges and grooves
thereon in the form of discrete forming elements. The other
satellite roll has continuous ridges and grooves thereon, such as a
ring roll. The nip between the raised ridge central roll 32 and the
satellite roll having discrete forming elements will be referred to
herein as the "primary nip" since this is the nip where two sets of
deformations are formed. The nip between the raised ridge central
roll 32 and the satellite roll that has continuous ridges and
grooves thereon will be referred to herein as the "secondary nip".
The secondary nip can occur either before or after the primary nip.
The depth of engagement can be the same in the primary and
secondary nips; or, the depth of engagement may vary between nips
(for example, so that the depth of engagement at the downstream nip
is greater).
[0137] In one non-limiting example of a case in which the secondary
nip occurs before the primary nip, the first satellite roll 34 can
comprise a ring roll and the second satellite roll 36 can comprise
a SELF roll. In such an embodiment, at the secondary nip between
the raised ridge central roll 32 and the ring roll 34, the raised
ridge central roll 32 will form a first set of deformations into
the web (for example, three dimensional apertures if the central
roll 32 is a raised ridge RKA roll, or protrusions if the central
roll 32 is a raised ridge SELF roll). In addition, the ring roll in
the secondary nip can pre-strain the web in the same CD location
that the SELF roll will impact the web downstream in the primary
nip, pre-weakening the web and making it easier to form the second
set of deformations. Then, downstream at the primary nip between
the raised ridge central roll 32 and the second satellite SELF roll
36, a second set of deformations can be formed into the web by the
SELF roll and the first set of deformations can be enlarged by the
raised ridge central roll 32.
[0138] In one non-limiting example of a case in which the secondary
nip occurs after the primary nip, the first satellite roll 34 can
comprise a SELF roll and the second satellite roll 36 can comprise
a ring roll. In such an embodiment, at the primary nip between the
raised ridge central roll 32 and the first satellite SELF roll 34,
these rolls will combine to form a first and a second set of
deformations into the web (for example, the central roll 32 will
form three dimensional apertures if the central roll 32 is a raised
ridge RKA roll, or protrusions if the central roll 32 is a raised
ridge SELF roll, and the SELF roll will form protrusions or tufts).
Then, downstream at the secondary nip between the raised ridge
central roll 32 and the second satellite ring roll 36, the first
set of deformations formed by the raised ridge central roll 32 can
be enlarged by the raised ridge central roll 32.
[0139] The variation of the apparatus of FIG. 14 described above
may be useful in providing greater flexibility in forming
deformations than the apparatus shown in FIG. 14. In the apparatus
shown in FIG. 14, which has a single nip, the amount of deformation
that can be imparted by the first and second forming components 162
and 170 is dependent upon the geometry of the tooling and the depth
of engagement of the forming components. These aspects are tied to
one another when there is a single nip. The variation of the
apparatus described above may provide the advantages of: (1)
allowing independent control over formation of the first and second
sets of deformations that are being formed; and, in some
configurations, (2) pre-straining the material in the locations
where the second set of deformations are to be formed.
[0140] B. Methods Utilizing Multiple Deformation Steps.
[0141] The methods of interest herein may also utilize multiple
deformation steps. Such multiple deformation steps can be carried
out by any suitable apparatuses described in the foregoing section
of this description. Although the methods that utilize multiple
deformation steps are shown as being carried out on nested
apparatuses having a relatively small number of rolls in a standard
nested arrangement, it should be understood that this is done for
simplicity of illustration, and any of the apparatuses described
herein (such as the hybrid, closed loop, and shared bank
apparatuses) could be used with any suitable number of rolls in
order to carry out the desired deformation.
[0142] Apparatuses that utilize multiple deformation steps for
forming inter-mixed features typically comprise a minimum of three
nips formed by a minimum of four rolls. Two of the nips are
deformation nips in which the web is permanently deformed to form a
first-time deformed precursor web with a first set of features and
a second-time deformed precursor web with a second set of features.
The third nip may be a transfer nip disposed between the
deformation nips in which the web is not permanently deformed. The
transfer nip may be used to dispose a different side of the web for
a subsequent deformation step such that different sets of features
can be formed on opposite sides of the web. The transfer nip can
also be used to off-set the rolls in subsequent deformation steps
such that the different sets of features can be formed in different
CD lanes, enabling tighter spacing of features. Depending on the
configuration and arrangement of the rolls, the forming elements in
the second deformation nip can contact the web in one of the
following locations: 1) the same location as in the first
deformation nip; 2) at least partially different locations wherein
at least some of the locations at least partially coincide with the
first location; and 3) in completely different locations.
[0143] The deformation nips comprise a first roll with discrete
male elements thereon and a second roll that is capable of mating
with the first roll to form discrete features. The first roll may
comprise a SELF roll, RKA roll, or male embossing roll. The second
roll preferably comprises a ring roll or a female emboss roll,
depending on the type of roll that is chosen for the first roll. In
some the cases, it may be desirable for the second roll to comprise
discrete male elements, for example when it is desired to use the
process to reduce the density of drylap or other wetlaid
structures. The rolls that comprise the transfer nips may be
capable of being arranged in either: i) a tip-tip configuration in
which the outwardmost portions on the surface of the rolls
substantially align to form a nip, or ii) an off-set configuration
in which the outwardmost portions on the surface of the rolls are
capable of meshing. Any of the rolls listed above (SELF roll, RKA
roll, ring roll, male embossing roll, female embossing roll) can be
used for the rolls in the transfer nip. Several specific
embodiments are detailed below in which the rolls with the discrete
male forming elements thereon that are used to form deformations
into the web are the first and the last rolls in the apparatus.
[0144] FIG. 16 shows an example of an apparatus 190 for deforming a
web 10 that comprises multiple rolls arranged in a nested
configuration. In this embodiment, the apparatus has four rolls
192, 194, 196, and 198. In apparatuses that utilize multiple
deformation steps, some of the nips can be used to deform the web,
and some of the nips, particularly the intermediate nips located
between the nips used to deform the web, can be used for other
purposes, such as transferring the web. For example, in some
non-limiting embodiments, such as shown in FIG. 16, some of the
rolls 194 and 196 can form an intermediate nip N2 which is used to
expose a different side of the web for a subsequent deformation
step. It should be understood, however, that in any of the
embodiments described herein, the rolls with the discrete male
forming elements thereon that are used to form deformations into
the web need not be the first and the last rolls in the apparatus.
In other embodiments, the rolls with the discrete male forming
elements thereon can comprise one or more of the intermediate
rolls. For example, the rolls with the discrete male forming
elements thereon can comprise the two intermediate rolls forming
the transfer nip, and the first and last rolls can comprise rolls
with mating female forming elements. Alternatively, the rolls may
alternate such that every other roll contains discrete male forming
elements thereon and every other roll in between comprises rolls
with mating female forming elements thereon. Regardless of the
configurations of the rolls, there may be at least one
non-permanently deforming transfer step in-between the deformation
steps.
[0145] The process carried out in the example on the apparatus
shown in FIG. 16 comprises initially feeding the web 10 into a
first nip N1 that is formed between a first pair of generally
cylindrical intermeshing rolls comprising a first roll 192 and a
second roll 194. In this example, the first roll 192 has a surface
with discrete male forming elements 200 thereon. The first roll 192
can comprise any suitable type of roll having such properties
including, but not limited to: a male embossing roll, an RKA roll,
or a SELF roll. In the embodiment shown in FIG. 16, the first roll
192 comprises an RKA roll. The second roll 194 should be capable of
forming a nip with the first roll 192 to form permanent
deformations in the web 10. The second roll 194 should also be
capable of cooperating with the third roll 196 to maintain control
of the web 10 and transfer the web, without permanently deforming
the same, to a downstream deforming nip. The second roll 194 has a
surface with projections 202 and/or recesses 204 thereon, wherein
any projections 202 or the portions of the roll between any
recesses form the radially outwardmost portions 206 on the surface
of the second roll 194. The second roll 194 can comprise any
suitable type of roll having such properties including, but not
limited to: a male or female embossing roll, a ring roll, or a SELF
roll. In the embodiment shown in FIG. 16, the second roll 194
comprises a ring roll. The nip N1 between the intermeshing first
and second rolls 192 and 194 is shown in cross-section in FIG.
16A.
[0146] The third roll 196 should also be capable of cooperating
with the second roll 194 to maintain control of the web 10 and
transfer the web, without permanently deforming the same, to a
downstream deforming nip. The third roll 196 has a surface with
projections 208 and/or recesses 210 thereon, wherein any
projections 208 or the portions of the roll between any recesses
210 form the radially outwardmost portions 212 on the surface of
the third roll 196. The third roll 196 can comprise any suitable
type of roll having such properties including, but not limited to:
a male or female embossing roll, a ring roll, or a SELF roll. In
the embodiment shown in FIG. 16, the third roll 196 comprises a
ring roll. The nip N2 between the second 194 and third 196 rolls is
shown in cross-section in FIG. 16B. As shown in cross-section in
FIG. 16B, the third roll 196 does not intermesh with the second
roll 194. Instead, the rolls are arranged so that the outwardmost
portions 202 on the second roll 194 align with the outwardmost
portions 212 of the third roll 196. The alignment of rolls with the
web shown in FIG. 16B may be referred to herein as a "tip-to-tip"
transfer. This transfers the web 10 and orients the web so that the
second surface 10B of the web 10 faces outward on the third roll
196. For rolls comprising ridges and grooves, the tip-tip transfer
also aligns the rolls in the subsequent deformation nip such that
the second set of formed features are substantially aligned in the
CD with the first set of formed features. The gap between the
transfer rolls is set such that the web is not permanently deformed
in the nip, but the rolls are in close enough proximity to ensure
there are no free spans of web greater than 2 cm and the web
remains in registration.
[0147] The web 10 is then fed into a third nip N3 between the third
roll 196 and a fourth roll 198. The nip N3 between the intermeshing
third and fourth rolls is shown in cross-section in FIG. 16C. The
fourth roll 198 has a surface with discrete forming elements 214
thereon. The fourth roll 198 can comprise any suitable type of roll
having such properties including, but not limited to: a male
embossing roll, an RKA roll, or a SELF roll. In the embodiment
shown in FIG. 16, the fourth roll 198 comprises a SELF roll. If it
is desired to create intermixed features as shown in FIGS. 17 and
18, the rolls in the deformation nips should be phased such that
the first and second sets of formed features are formed in at least
partially different locations relative to each other.
[0148] The elements on the various rolls shown in FIG. 16 include,
but are not limited to: cross-machine direction elements, machine
direction elements, elements that are aligned in rows or have a
staggered alignment of forming elements, elements that are not
aligned in rows with uneven/irregular spacing, and elements on
rolls having a raised ridge configuration. The meshing pairs of
rolls should be designed and configured in a way that allows for
sufficient clearance of the web at the desired depth of
engagement.
[0149] When the precursor web 10 is fed into the first nip N1 in
the apparatus shown in FIG. 16, the web 10 is deformed in a first
location to form a first set of formed features in the web 10. The
first set of formed features comprises portions in first locations
of the web that extend outward from the second surface 10B of the
web. Examples of such formed features are shown in FIGS. 17 and 18,
which are described in greater detail below. The type and alignment
of the formed features depends on the configuration and alignment
of the rolls. The precursor web 10 is then fed into a second nip N2
to contact the web 10 and transfer the web from the second roll 194
to the third roll 196. This transfers the web 10 and orients the
web so that the second surface 10B of the web 10 faces outward on
the third roll 196. When the web is fed into the third nip N3
between the third and fourth rolls 196 and 198, the web 10 is
deformed in second locations in which at least some of the forming
elements 214 in the third nip N3 deform the first-time deformed
precursor web at least partially in different locations and in a
different orientation than the precursor web was deformed in the
first nip N1. In the third nip, the web 10 is permanently deformed
in second locations to form a second set of formed features in the
web. The second set of formed features comprises portions that
extend outward from the first surface 10A of the web to form a
second time-deformed precursor web.
[0150] FIG. 17 shows an embodiment of a nonwoven web 10 made using
the apparatus shown in FIG. 16, in which the first roll 192 is a
staggered RKA roll and the fourth roll 198 is a staggered CD SELF
roll. In FIG. 17, the first features (in the first locations),
which are formed in the first nip N1, comprise a plurality of
spaced apart apertures 182. The second features (in the second
locations), which are subsequently formed in the third nip N3,
comprise a plurality of spaced apart tufts 184. The apertures 182
are pushed out of the plane of the web in one direction (downward
as viewed in FIG. 17), and the tufts 184 are pushed out of the
plane of the web in the opposite direction (upward). As shown in
FIG. 17, the apertures 182 are aligned in rows in the MD, the CD,
and diagonally. The tufts 184 are also aligned in rows in the MD,
the CD, and diagonally. However, there are spaces between each of
the apertures 182 and a tuft 184 is located in each of these
spaces. In other words, the tufts 184 are intermixed with the
apertures. The first and second features may lie in substantially
the same MD and CD rows so that the first and second features
alternate in the MD and CD. In this embodiment, the tufts 184 may
be separated from the adjacent rows of apertures 182 by a distance
in the cross-machine direction (CD) approximately equal to the
pitch between the rows of apertures 184.
[0151] When the features are described as being substantially
aligned, or lying in substantially the same rows, this refers to at
least a majority of the specified features. Thus, if the second
features are described as lying substantially in the same rows as
the first features, at least a majority of the second features lie
in the same rows as the first features. Of course, in any of the
embodiments described herein, the first and second features may be
offset relative to each other so that they do not lie in
substantially the same rows. The second features also need not be
spaced between the first features such that there in equal spacing
between the features on each side.
[0152] FIG. 18 shows an embodiment of a nonwoven web 10 made using
the apparatus shown in FIG. 16, in which the first roll 192 is a
standard RKA roll and the fourth roll 198 is a standard CD SELF
roll. In FIG. 18, the first features, which are formed in the first
nip N1, comprise a plurality of spaced apart apertures 182, and the
second features, which are subsequently formed in the third nip N3,
comprise a plurality of spaced apart tufts 184. The apertures 182
are pushed out of the plane of the web 10 in one direction
(downward as viewed in FIG. 18), and the tufts 184 are pushed out
of the plane of the web 10 in the opposite direction (upward). As
shown in FIG. 18, the apertures 182 are substantially aligned in
rows in the MD and the CD. The tufts 184 are also substantially
aligned in rows in the MD and CD. The rows of tufts 184 are,
however, aligned between the rows of apertures 182 in the MD so
that there is a row of tufts 184 between every row of apertures
182, and the tufts 184 and apertures 182 alternate in each MD row.
The distance between the features in adjacent MD rows is
approximately equal to the pitch in the cross-machine direction
(CD).
[0153] FIG. 19 shows a non-limiting example of an apparatus 220 and
process that is used to deform a web so that subsequent
deformations are formed in a different orientation and at a
different CD location than prior deformations. Such a process may
be used to achieve tighter spacing between deformations than might
otherwise be possible, particularly in those processes with rolls
containing ridges and grooves.
[0154] The apparatus 220 shown in FIG. 19 comprises four rolls,
222, 224, 226, and 228. The apparatus 220 shown in FIG. 19 is
similar to the apparatus shown in FIG. 16, except with respect to
the alignment of the rolls in the nip N2 between the second and
third rolls 224 and 226. The rolls forming the nip N2 are arranged
in an offset manner, rather than in a tip-to-tip manner. The second
and third rolls 224 and 226 are of configurations that are capable
of at least partially intermeshing. In the embodiment shown in FIG.
19, the second and third rolls, 224 and 226, can comprise surfaces
with discrete and/or continuous forming elements thereon. The nips
between the various rolls of the apparatus 220 shown in FIG. 19 are
shown in FIGS. 19A, 19B, and 19C. As shown in FIG. 19A, the first
nip N1 between the first and second rolls 222 and 224 may be
similar to the first nip of the apparatus shown in FIG. 16. The
forming elements 230 on the first roll 222 intermesh with the
(projections 232 and) recesses 234 on the second roll 224. FIG. 19B
shows the second nip N2 between the second and third rolls 224 and
226. As shown in FIG. 19B, the second and third rolls 224 and 226
are not aligned with the elements thereon in a tip-to-tip alignment
as in the case of apparatus shown in FIG. 16, but are instead
aligned so that the tips 236 and 242, respectively, of the elements
on one of the rolls align with the grooves 240 and 234,
respectively, on the opposing roll. The registration of the second
and third rolls 224 and 226, however, does not require that the
tips 236 and 242, respectively, of the elements on one of the rolls
align exactly with the center of the grooves on the opposing roll.
The tips of the elements can be offset from the center of the
grooves on the opposing roll, if desired. As shown in FIG. 19C, the
third nip N3 between the third and fourth rolls 226 and 228 is
similar to that in the apparatus shown in FIG. 16. The difference
in alignment of the second and third rolls 224 and 226 causes the
alignment of the forming elements 244 on the fourth roll 228 to be
shifted (such as a distance of up to one-half pitch) relative to
the alignment in apparatus shown in FIG. 16. The intermediate
second and third rolls 224 and 226 can be aligned to provide any
suitable shift in the alignment of the forming elements 244 on the
fourth roll 228 (and, thus, the web 10 deformed thereby) up to
one-half the pitch between the forming elements on the roll used to
form the first set of features.
[0155] When the precursor web 10 is fed into the apparatus shown in
FIG. 19, in the first nip N1 (shown in FIG. 19A), the precursor web
10 is deformed in a first location to form a first set of formed
features in the web, such as the three dimensional apertures 182
shown in FIG. 20. The apertures 182 extend outward from the second
surface 10B of the web (downward in FIG. 20). The web 10 is then
fed into the second nip N2 (shown in FIG. 19B) in order to contact
the web 10 and transfer the precursor web 10 from the second roll
224 to the third roll 226. The third roll 226 has a surface with a
plurality of outwardly-extending male elements 238 on its surface.
As shown in FIG. 19B, the rolls are arranged so that the
outwardly-extending male elements 232 on the second roll 224 are
aligned in a cross-machine direction between the
outwardly-extending male elements 238 on the third roll 226, and
the second surface 10B of the web faces outward on the third roll
226. The third roll 226 either: (i) does not intermesh with the
second roll; or (ii) intermeshes with the second roll but not to
the extent that the precursor web 10 will be permanently deformed
in the second nip N2. The web 10 is then fed into a third nip N3
(shown in FIG. 19C) between the third roll 226 and the fourth roll
228. The fourth roll 228 has forming elements 244 on its surface.
When the precursor web 10 is fed into the third nip N3, the
precursor web 10 is deformed in a second location. In this step, at
least some of the forming elements 244 in the third nip N3 deform
the first-time deformed precursor web 10 at least partially in
different (or second) locations than the precursor web 10 was
deformed in the first nip N1. This forms a second set of formed
features in the web, wherein the features comprise portions that
extend outward from the first surface 10A of the web to form a
second time-deformed precursor web 10.
[0156] Any suitable combinations of the apparatuses and processes
described herein are also possible. FIG. 21, for example shows an
embodiment of a process and apparatus that combines some of the
features in the processes shown in FIGS. 16 and 19. In this
embodiment, the apparatus 250 has five rolls 252, 254, 256, 258,
and 260. The process carried out on this apparatus comprises
initially feeding the precursor web 10 into a first nip N1 that is
formed between a first pair of generally cylindrical intermeshing
rolls. The first pair of intermeshing rolls comprises a first roll
252 and a second roll 254. The first roll 252 has a surface with
discrete male forming elements 262 thereon, and the second roll 254
has a surface with projections 264 and/or recesses 266 thereon,
wherein any projections 264 or the portions of the second roll
between any recesses form the radially outwardmost portions 268 on
the surface of the second roll 254. When the precursor web 10 is
fed into the first nip N1 (shown in FIG. 21A), the precursor web 10
is deformed in a first location to form a first set of formed
features in the web. The first set of formed features comprises
portions that extend outward from the second surface 10B of the
web. The precursor web 10 is then fed into the second nip N2 (shown
in FIG. 21B) to contact the web 10 and transfer the web 10 from the
second roll 254 to the third roll 256. The third roll 256 has a
surface with projections 270 and/or recesses 272 thereon, wherein
any projections 272 or the portions of the roll between any
recesses form the radially outwardmost portions 274 on its surface.
The third roll 256 does not intermesh with the second roll 254. The
rolls are arranged so that the outwardmost portions 268 on the
second roll 254 substantially align with the outwardmost portions
274 on the third roll 256 to perform a tip-to-tip transfer of the
web 10, and the second surface 10B of the web faces outward on the
third roll 256. The precursor web 10 is then fed into a third nip
N3 (shown in FIG. 21C) to contact the web 10 and transfer the web
from the third roll 256 to the fourth roll 258. The fourth roll 258
has a surface with projections 276 and/or recesses 278 thereon,
wherein any projections or the portions of the fourth roll 258
between any recesses form the radially outwardmost portions 280 on
its surface. The rolls are arranged so that the outwardmost
portions 274 on the third roll 256 are aligned in a cross-machine
direction between the outwardmost portions 280 on the fourth roll
258, and the first surface 10A of the web faces outward on the
fourth roll 258. The web 10 is then fed into a fourth nip N4 (shown
in FIG. 21D) between the fourth roll 258 and a fifth roll 260. The
fifth roll 260 has forming elements 282 on its surface. When the
web 10 is fed into the fourth nip N4, the web 10 is deformed in a
second location in which at least some of the forming elements 282
in the fourth nip N4 deform the first-time deformed precursor web
at least partially in different locations than the web was deformed
in the first nip N1 to form a second set of formed features in the
web, wherein the features comprise portions that also extend
outward from the second surface 10B of the web to form a second
time-deformed precursor web. Such an apparatus 250 can be used for
numerous purposes including, but not limited to, deforming the web
in different CD lanes for increased density of formed features, or
intermixing elements that cannot economically be machined into a
single roll.
[0157] FIG. 22 shows an embodiment of a nonwoven web 10 made using
the apparatus shown in FIG. 21, in which the first roll 252 is a
standard CD SELF roll and the fifth roll 260 is a standard RKA
roll, and the second, third and fourth rolls are ring rolls. In
FIG. 22, the second regions comprise a plurality of spaced apart
apertures 182, and the third regions comprise a plurality of spaced
apart tufts 184. The apertures 182 and tufts 184 are both pushed
out of the plane of the web in the same direction (shown as being
upward). As shown in FIG. 22, the apertures 182 are aligned in rows
in the MD and the CD. The rows of tufts 184 are, however, aligned
between the rows of apertures 182 in the MD and the CD, with the
rows of tufts 184 being offset in the CD such that they are
separated from the adjacent rows of apertures 182 by a distance of
up to one half of the pitch between the apertures 182 in the
cross-machine direction (CD).
[0158] FIG. 23 shows an embodiment of a nonwoven web 10 made using
a variation of the planetary roll apparatus shown in FIG. 14. In
the apparatus used to form the web shown in FIG. 23, the satellite
rolls can comprise discrete male forming elements, and the
central/sun roll can have continuous (as in grooves) or discrete
female elements with which the discrete forming elements can mesh.
For example, the central roll can be a ring roll, and the two
satellite rolls can comprise a staggered RKA roll and a staggered
SELF roll, which are phased in the MD to be offset so they impact
the web in different MD locations. In FIG. 23, the second regions
comprise a plurality of spaced apart apertures 182, and the third
regions comprise a plurality of spaced apart tufts 184. The
apertures 182 and tufts 184 are both pushed out of the plane of the
web in the same direction (shown as being upward). As shown in FIG.
23, the apertures 182 are aligned in rows in the MD, the CD, and
diagonally. The tufts 184 are also aligned in rows in the MD, the
CD, and diagonally. However, there are spaces between each of the
apertures 182 in the MD and CD rows of apertures 182, and a tuft is
located in each of these spaces. In other words, the tufts 184 are
intermixed with the apertures 182 and may lie in substantially the
same MD and CD rows as the apertures 182 such that the second and
third regions alternate in the MD and CD. The tufts 184 are
separated from the adjacent rows of apertures 182 by a distance in
the cross-machine direction (CD) approximately equal to the pitch
between the apertures 182.
[0159] C. Alternative Embodiments.
[0160] Numerous alternative embodiments of the deformed web
materials and methods of making the same are possible.
[0161] The methods described herein need not always be used to
produce intermixed sets of elements that are in different locations
on a web. In alternative embodiments, the method can, for example,
comprise feeding a web through a "nested roll" arrangement in which
at least two of the rolls define two or more nips thereon with
other rolls, and the apparatus can be configured to deform the web
in the same location at each nip. Such an apparatus and method can
be used to lower the strain rate on the areas of the web that are
impacted to produce deformations. For example, it may be desirable
to initially deform the web to a degree in an initial nip, and then
deform the web to a greater degree in a subsequent nip.
[0162] In some alternative embodiments, the method can comprise
feeding a web through an apparatus with multiple deformation nips,
and the apparatus can be configured to deform the web in the same
location, but on the opposite surface of the web. This could be
useful for reducing the density of drylap or other wetlaid
structures.
[0163] In other alternative embodiments, the method can comprise
feeding a web through an apparatus with multiple deformation nips,
and the apparatus can be configured to deform the web in the same
location and on the same surface of the web, but the size and/or
shape of the forming elements in the first deformation nip is
different from that of the forming elements in the subsequent
deformation nip. Such an apparatus could, for example, be used to
initially form a formed element (such as a three-dimensional region
with an aperture, a protrusion, or depression) at a first nip, and
then, at a second nip, to make the formed element larger, or of a
different shape.
[0164] In other embodiments, deformed web materials can be provided
which have different regions across their surface with different
features therein. For example, a deformed web material can be
provided which has a first region with a first combination of
features (such as tufts extending upward that are intermixed with
downwardly extending tufts), and a second region with a second
combination of features (such as upwardly-oriented tufts and
downwardly-oriented apertures).
[0165] In any of the embodiments described herein, the web can
comprise one or more layers. Additional webs may be introduced at
any of the different nips. The additional layers may be used to add
webs having different chemical compositions, formulations,
aesthetics, conductive properties, aromatic properties, and
mechanical properties. Such additional webs may be selected so that
they may or may not span the entire width of the web or webs that
were introduced upstream of such additional web(s). This may be
used to create a laminate in which some regions of the laminate
contain a different number of layers from other regions. In other
laminate structures, the regions may contain the same number of
layers, but some deformed features could have a different number of
layers through their thickness. For example, tufts could be formed
into a nonwoven web material 14 in a first nip, and then a film 16
could be introduced in a second nip downstream of the first nip.
Such a method could be used to form film/nonwoven tufts in a second
nip. As shown in FIG. 24, the overall laminate may comprise some
tufts 184 with a nonwoven with a film spanning below the tufts (in
those locations not impacted by forming elements in the second
nip), while other tufts (impacted by the forming elements in the
second nip) will contain both the film and nonwoven within the
tuft. Numerous variations of such a method, and the resulting
structures are possible, depending on the forming elements and the
type and order of introduction of the different webs. The multi-hit
process described herein enables independent control of the
features formed in a multi-layer structure, providing additional
control over the function and aesthetics of the features.
[0166] In another alternative embodiment, the method can comprise
feeding a web through an apparatus that comprises multiple nips
formed by SELF rolls in order to more gradually strain a web than
is possible with ring rolling processes. SELF rolls are known to
more gradually strain a web than ring rolls, since less material is
locked on the tooth and constrained during the deformation step.
The apparatus can be configured to deform the web in multiple
discrete locations such as in a first location on the web, then
immediately adjacent to the first location. The deformation steps
are repeated until all the regions within a row are deformed and
form a continuous band of deformations that resemble a ring rolled
web. The SELF rolls in such an apparatus can comprise CD, MD, or
staggered CD or MD SELF rolls. The rolls in such an apparatus will
typically all be either CD or MD SELF rolls. The depth of
engagement of the SELF teeth in such an embodiment may, but need
not, be increased in downstream nips.
EXAMPLES
[0167] In one non-limiting example for making inter-mixed apertures
and tufts oriented in opposite directions in a nonwoven web
material, like that shown in FIG. 15, an apparatus can be used that
comprises a 80 pitch raised ridge RKA roll intermeshed with a 80
pitch SELF roll, like that shown in FIG. 14C. When a number, such
as "80" is given to describe the pitch, this refers to the number
in thousands of an inch (0.0254 mm). The nonwoven material can have
any suitable basis weight, down to about 15 gsm. In this example,
it comprises a 28 gsm spunbonded polyethylene sheath/polypropylene
core bicomponent fiber nonwoven. The raised ridge RKA roll has
discrete forming elements that are oriented so the long direction
runs in the MD. The teeth are arranged in a standard pattern,
meaning adjacent teeth align in rows in the CD. The teeth on the
RKA roll have a pyramidal shape with 6 sides that taper from the
base to a sharp point at the tip. The tooth height TH is 0.270 inch
(6.9 mm), the ridge height is 0.170 inch (4.3 mm), the side wall
angle on the long side of the tooth is about 5 degrees and the side
wall angle of the leading and trailing edges of the teeth is 28.5
degrees. The RKA roll comprises teeth that are evenly spaced in the
MD, with a tip to tip spacing in the MD of 0.320 inch (8.1 mm) and
a CD pitch P of 0.080 inch (2 mm). The teeth on the SELF roll are
also arranged in a standard pattern and are oriented such that the
long direction runs in the MD. The teeth have a uniform
circumferential length dimension TL of about 0.080 inch (2 mm)
measured generally from the leading edge LE to the trailing edge
TE, a tooth tip radius TR at the tooth tip of about 0.005 inch
(0.13 mm), are uniformly spaced from one another circumferentially
by a distance TD of 0.240 inch (6.1 mm), and have a tooth height TH
of about 0.270 inch (6.9 mm). The long sides of the teeth have a
side wall angle of about 3 degrees, and the leading and trailing
edges of the teeth have vertical side walls. Both rolls have a
diameter of about 5.7 inch (14.5 cm) and are heated to a
temperature of 130 deg C. The RKA and the SELF roll are aligned in
the CD such that the clearances on either side of the teeth are
about equal. The RKA and SELF rolls are MD phased such that the
forming teeth on the SELF roll align with the raised ridges on the
RKA roll, and the rolls are engaged to a depth of 0.250 inch (6.4
mm).
[0168] In a second non-limiting example for making inter-mixed
apertures and tufts oriented in opposite directions in a nonwoven
web material, like that shown in FIG. 17, a 4-roll nested apparatus
with a tip-tip transfer roll can be used, such as that shown in
FIG. 16. The nonwoven material can have any suitable basis weight,
down to about 15 gsm. In this example, it comprises a 28 gsm
spunbonded polyethylene sheath/polypropylene core bicomponent fiber
nonwoven. The first nip N1 comprises a 100 pitch staggered RKA roll
intermeshed with a 100 pitch ring roll at 0.200 inch (5.1 mm) depth
of engagement. The teeth on the RKA roll have a pyramidal shape
with six sides that taper from the base to a sharp point at the tip
and are oriented so the long direction runs in the MD. The teeth
are arranged in a staggered pattern, with a CD pitch P of 0.100
inch (2.5 mm) and a uniform tip to tip spacing in the MD of 0.250
inch (6.5 mm). The tooth height TH is 0.270 inch (6.9 mm), the side
wall angle on the long side of the tooth is 4.7 degrees and the
side wall angle of the leading and trailing edges of the teeth is
22.5 degrees. The 100 pitch ring roll also has a CD pitch P of
0.100 inch, a tooth height TH of 0.270 inch, a tip radius TR of
0.005 inch, and a side wall angle of 4.7 degrees. The RKA roll and
ring roll are aligned in the CD such that the clearances on either
side of the teeth are about equal. The second nip N2 comprises a
100 pitch ring roll aligned with a second 100 pitch ring roll, in a
tip-tip configuration (as shown in FIG. 16B) with a -0.050'' (-1.25
mm) depth of engagement. The third nip N3 comprises a 100 pitch
ring roll intermeshed with a 100 pitch SELF roll at 0.135 inch (3.4
mm) depth of engagement. The teeth on the 100 pitch SELF roll form
a staggered pattern, are oriented such that the long dimension runs
in the MD, and have a CD pitch P of about 0.100 inch. The teeth
have a uniform circumferential length dimension TL of about 0.120
inch (3 mm) measured generally from the leading edge LE to the
trailing edge TE, a tooth tip radius TR at the tooth tip of about
0.005 inch (0.127 mm), are uniformly spaced from one another
circumferentially by a distance TD of about 0.130 inch (3.3 mm),
and have a tooth height TH of about 0.270 inch (6.9 mm). The long
sides of the teeth have a side wall angle of about 4.7 degrees, and
the leading and trailing edges of the teeth have vertical side
walls. The SELF roll and ring roll are aligned in the CD such that
the clearances on either side of the teeth are about equal. All
four rolls (RKA roll, SELF roll, two ring rolls) have a diameter of
about 5.7 inches (14.5 cm). The SELF and RKA rolls are MD phased
such that the tufts are formed approximately half-way between the
apertures in the MD.
[0169] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "90.degree." is intended to mean "about
90.degree.".
[0170] It should be understood that every maximum numerical
limitation given throughout this specification includes every lower
numerical limitation, as if such lower numerical limitations were
expressly written herein. Every minimum numerical limitation given
throughout this specification will include every higher numerical
limitation, as if such higher numerical limitations were expressly
written herein. Every numerical range given throughout this
specification will include every narrower numerical range that
falls within such broader numerical range, as if such narrower
numerical ranges were all expressly written herein.
[0171] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference;
the citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention. To the
extent that any meaning or definition of a term in this written
document conflicts with any meaning or definition of the term in a
document incorporated by reference, the meaning or definition
assigned to the term in this written document shall govern.
[0172] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
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