U.S. patent application number 16/949617 was filed with the patent office on 2021-02-25 for apparatus and method for forming absorbent cores.
The applicant listed for this patent is Curt G. Joa, Inc.. Invention is credited to Collin Heinz, Chris Nelson.
Application Number | 20210052434 16/949617 |
Document ID | / |
Family ID | 1000005197390 |
Filed Date | 2021-02-25 |
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United States Patent
Application |
20210052434 |
Kind Code |
A1 |
Nelson; Chris ; et
al. |
February 25, 2021 |
APPARATUS AND METHOD FOR FORMING ABSORBENT CORES
Abstract
Several variations of core formation techniques and machines to
produced cores are disclosed, including a large and small discrete
core, formed on a screen and combined; a large and small continuous
core, formed on a web; and two and three-dimensional cores, formed
on a screen, and core formation on a non-woven web.
Inventors: |
Nelson; Chris; (Plymouth,
WI) ; Heinz; Collin; (Plymouth, WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Curt G. Joa, Inc. |
Sheboygan Falls |
WI |
US |
|
|
Family ID: |
1000005197390 |
Appl. No.: |
16/949617 |
Filed: |
November 6, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13607127 |
Sep 7, 2012 |
10828204 |
|
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16949617 |
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61532418 |
Sep 8, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 13/15699 20130101;
A61F 13/15764 20130101 |
International
Class: |
A61F 13/15 20060101
A61F013/15 |
Claims
1-20. (canceled)
21. An absorbent core forming system comprising: a first
core-forming drum configured to form a first core; a second
core-forming drum configured to form a second core; an absorbent
material introduction unit positioned adjacent each of the first
core-forming drum and the second core-forming drum and configured
to apply an absorbent material thereon for forming the first and
second cores; a web introduction unit positioned adjacent to the
first core-forming drum and/or the second core-forming drum and
configured to introduce a non-woven web to the first core-forming
drum and/or the second core-forming drum, with the absorbent
material applied onto the non-woven web; a first debulking unit
configured to debulk the first core; a second debulking unit
configured to debulk the second core positioned downstream from the
first debulking unit; and a means for combining the debulked first
core and the debulked second core to form an assembled absorbent
core.
22. The system of claim 21 wherein at least one of the first
debulking unit and the second debulking unit comprises a calendar
unit configured to mechanically compress the first core and/or the
second core.
23. The system of claim 21 wherein the means for combining the
debulked first core and the debulked second core comprises a
conveyor on which the first core and the second core are
translated.
24. The system of claim 23 wherein the means for combining the
debulked first core and the debulked second core further comprises
one or more accelerator units configured to accelerate a speed of
at least one of the first core and the second core to move at a
same speed as the other of the first core and the second core
moving on the conveyor.
25. The system of claim 21 wherein the absorbent material comprises
a super absorbent polymer (SAP) or a mixture of fluff and SAP.
26. The system of claim 25 wherein at least one of the first
core-forming drum and the second core-forming drum comprises a
discrete pocket formed therein in which the SAP or mixture of fluff
and SAP is applied, so as to form a discrete core in the discrete
pocket.
27. The system of claim 25 wherein at least one of the first
core-forming drum and the second core-forming drum comprises a
continuous pocket formed therein in which the SAP or mixture of
fluff and SAP is applied, so as to form a continuous core material
in the continuous pocket; and wherein the system further comprises
a knife configured to cut the continuous core material, after
debulking thereof, to form discrete cores.
28. The system of claim 25 further comprising a third absorbent
material introduction unit positioned adjacent one or more of the
first core-forming drum and the second core-forming drum and
configured to apply fluff onto the SAP or mixture of fluff and
SAP.
29. The system of claim 21 wherein the web introduction unit is
positioned adjacent to the first core-forming drum and configured
to introduce the non-woven web thereon; and wherein the system
further comprises: a tissue applicator unit positioned adjacent to
the second core-forming drum and configured to: apply a base tissue
layer to the second core-forming drum such that the absorbent
material is applied onto the base tissue layer; and apply an upper
tissue layer to the second core after the second core has been
removed from the second core-forming drum, with the base tissue
layer and top tissue layer wrapping the second core; and a knife
station configured to cut the upper and lower tissue layers, so as
to form a discrete wrapped second core.
30. A method of forming an absorbent core comprising: forming a
first core on a first core-forming drum; debulking the first core
at a first debulking unit; forming a second core on a second
core-forming drum; debulking the second core at a second debulking
unit that is separate from the first debulking unit; and combining
the debulked first core and the debulked second core to form an
assembled absorbent core; wherein forming the first core and/or
forming the second core further comprises introducing a non-woven
web to the first core-forming drum and/or the second core-forming
drum and applying an absorbent material onto the non-woven web, the
absorbent material comprising super absorbent polymer (SAP) or a
combination of fluff and SAP.
31. The method of claim 30 wherein debulking the first core and
debulking the second core comprises calendaring the first core and
the second core to mechanically compress the first core and the
second core.
32. The method of claim 30 wherein, in combining the debulked first
core and the debulked second core, the method comprises: after
debulking the first core, depositing the first core onto a running
web; conveying the running web and the first core toward the second
core-forming drum; and after debulking the second core, depositing
the second core onto the first core.
33. The method of claim 32 further comprising: receiving the second
core at a core acceleration unit; accelerating the second core with
the core acceleration unit; and depositing the second core from the
core acceleration unit onto the first core, with the core
acceleration unit functioning to adjust a speed of the second core
to align the second core with the first core.
34. The method of claim 30 wherein at least one of said first and
said second cores are formed as a continuous core web, said
continuous core web cut by a knife to form discrete cores.
35. The method of claim 30 wherein the first core is formed by
applying the absorbent material onto the non-woven web and the
second core is formed without the non-woven web, and wherein
forming the second core comprises: applying a base tissue layer to
the second core-forming drum; applying the SAP or combination of
fluff and SAP onto the base tissue layer; and applying an upper
tissue layer to the second core after the second core has been
removed from the second core-forming drum, with the base tissue
layer and top tissue layer wrapping the second core.
36. The method of claim 35 further comprising cutting the upper and
base tissue layers via a knife station, so as to form a discrete
wrapped second core.
37. The method of claim 36 wherein combining the debulked first
core and the debulked second core comprises: depositing the
discrete wrapped second core onto the debulked first core;
depositing the discrete wrapped second core and the debulked first
core onto a poly layer; and compressing the discrete wrapped second
core and the debulked first core via a compression unit, to form
the assembled absorbent core.
38. An absorbent core forming system comprising: material supply
units configured to provide absorbent core material; a first
core-forming drum positioned to receive absorbent core material
from one of the material supply units and configured to form a
first core; a second core-forming drum positioned to receive
absorbent core material from one of the material supply units and
configured to form a second core; a web introduction unit
positioned adjacent to the first core-forming drum and/or the
second core-forming drum and configured to introduce a non-woven
web to the first core-forming drum and/or the second core-forming
drum, with the absorbent core material applied onto the non-woven
web; a first debulking unit positioned adjacent the first
core-forming drum and configured to debulk the first core; a second
debulking unit positioned adjacent the second core-forming drum
configured to debulk the second core and that is separate from the
first debulking unit; and a means for combining the debulked first
core and the debulked second core to form an assembled absorbent
core; wherein the first debulking unit and second debulking unit
interact with the first core-forming drum and second core-forming
drum, respectively, to compress the first core and the second
core.
39. The system of claim 38 wherein at least one of the first
core-forming drum and the second core-forming drum comprises a
discrete pocket formed therein in which the absorbent core material
is applied, so as to form a discrete core in the discrete
pocket.
40. The system of claim 38 wherein at least one of the first
core-forming drum and the second core-forming drum comprises a
continuous pocket formed therein in which the absorbent core
material is applied, so as to form a continuous core material in
the continuous pocket; and wherein the system further comprises a
knife configured to cut the continuous core material, after
debulking thereof, to form discrete cores.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is a continuation of and claims
priority to U.S. Nonprovisional patent application Ser. No.
13/607,127, filed Sep. 7, 2012, which is a nonprovisional of U.S.
Provisional Patent Application Ser. No. 61/532,418, filed Sep. 8,
2011, the disclosures of which are incorporated herein by reference
in their entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates to formation of absorbent cores for
use in disposable products such as diapers and sanitary
napkins.
[0003] Sanitary napkins used in feminine hygiene are absorbent
items worn by women to recover undesirable bodily discharges. These
absorbent articles are typically comprised of an absorbent core
sandwiched between layers of woven or non-woven materials.
[0004] Generally, diapers comprise an absorbent insert or patch and
a chassis, which, when the diaper is worn, supports the insert
proximate a wearer's body. Additionally, diapers may include other
various patches, such as tape tab patches, reusable fasteners and
the like. The raw materials used in forming a representative insert
are typically cellulose pulp, tissue paper, poly, nonwoven web,
acquisition, and elastic, although application specific materials
are sometimes utilized. Usually, most of the insert raw materials
are provided in roll form, and unwound and applied in assembly line
fashion.
[0005] In the creation of a diaper (and, oftentimes also in
conjunction with feminine hygiene products), multiple roll-fed web
processes are typically utilized.
[0006] To create an absorbent insert, the cellulose pulp is unwound
from the provided raw material roll and pulverized by a pulp mill.
Discrete pulp cores are formed by a core forming assembly and
placed on a continuous tissue web. Optionally, super-absorbent
powder may be added to the pulp core. The tissue web is wrapped
around the pulp core. The wrapped core is debulked by proceeding
through a calendar unit, which at least partially compresses the
core, thereby increasing its density and structural integrity.
After debulking, the tissue-wrapped core is passed through a
segregation or knife unit, where individual wrapped cores are cut.
The cut cores are conveyed, at the proper pitch, or spacing, to a
boundary compression unit.
[0007] While the insert cores are being formed, other insert
components are being prepared to be presented to the boundary
compression unit. For instance, the poly sheet is prepared to
receive a cut core. Like the cellulose pulp, poly sheet material is
usually provided in roll form. The poly sheet is fed through a
splicer and accumulator, coated with an adhesive in a predetermined
pattern, and then presented to the boundary compression unit. In
addition to the poly sheet, which may form the bottom of the
insert, a two-ply top sheet may also be formed in parallel to the
core formation. Representative plies are an acquisition web
material and a nonwoven web material, both of which are fed from
material rolls, through a splicer and accumulator. The plies are
coated with adhesive, adhered together, cut to size, and presented
to the boundary compression unit. Therefore, at the boundary
compression unit, three components are provided for assembly: the
poly bottom sheet, the core, and the two-ply top sheet.
[0008] A representative boundary compression unit includes a die
roller and a platen roller. When all three insert components are
provided to the boundary compression unit, the nip of the rollers
properly compresses the boundary of the insert. Thus, provided at
the output of the boundary compression unit is a string of
interconnected diaper inserts. The diaper inserts are then
separated by an insert knife assembly and properly oriented. At
this point, the completed insert is ready for placement on a diaper
chassis.
[0009] A representative diaper chassis comprises nonwoven web
material and support structure. The diaper support structure is
generally elastic and may include leg elastic, waistband elastic
and belly band elastic. The support structure is usually sandwiched
between layers of the nonwoven web material, which is fed from
material rolls, through splicers and accumulators. The chassis may
also be provided with several patches, besides the absorbent
insert. Representative patches include adhesive tape tabs and
resealable closures.
[0010] The process utilizes two main carrier webs; a nonwoven web
which forms an inner liner web, and an outer web that forms an
outwardly facing layer in the finished diaper. In a representative
chassis process, the nonwoven web is slit at a slitter station by
rotary knives along three lines, thereby forming four webs. One of
the lines is on approximately the centerline of the web and the
other two lines are parallel to and spaced a short distance from
the centerline. The effect of such slicing is twofold; first, to
separate the nonwoven web into two inner diaper liners. One liner
will become the inside of the front of the diaper, and the second
liner will become the inside of the back of that garment. Second,
two separate, relatively narrow strips are formed that may be
subsequently used to cover and entrap portions of the leg-hole
elastics. The strips can be separated physically by an angularly
disposed spreader roll and aligned laterally with their downstream
target positions on the inner edges of the formed liners.
[0011] After the nonwoven web is sliced, an adhesive is applied to
the liners in a predetermined pattern in preparation to receive
leg-hole elastic. The leg-hole elastic is applied to the liners and
then covered with the narrow strips previously separated from the
nonwoven web. Adhesive is applied to the outer web, which is then
combined with the assembled inner webs having elastic thereon,
thereby forming the diaper chassis. Next, after the elastic members
have been sandwiched between the inner and outer webs, an adhesive
is applied to the chassis. The chassis is now ready to receive an
insert.
[0012] To assemble the final diaper product, the insert must be
combined with the chassis. The placement of the insert onto the
chassis occurs on a placement drum or at a patch applicator. The
inserts are provided to the chassis on the placement drum at a
desired pitch or spacing. The generally flat chassis/insert
combination is then folded so that the inner webs face each other,
and the combination is trimmed. A sealer bonds the webs at
appropriate locations prior to individual diapers being cut from
the folded and sealed webs.
[0013] Generally, disposable undergarments such as pants-type
diapers are made up of two nonwoven layers of material with elastic
strands of material placed between the two nonwoven layers of
material thus creating an elastic web laminate. The layers of
material are continuous sheets of material that are eventually cut
into individual undergarment lengths. The elastic strands may be
arranged and cut so that specific areas of the undergarment are
free of elastic tension or forces. An absorbent pad, often
contained within an insert or core is then also placed into the
pants-type diaper product.
[0014] To insure the pants-type diaper retains a proper shape and
to hold all of the added layers of the diaper, reinforcing layers
and backing materials are normally added to the continuous sheets
of material, with the reinforcing layers corresponding to the cut
elastic strands of each individual blank. Each of these layers
needs to be adhesively joined at some point in the manufacturing
process to the elastic web laminate to form the completed
undergarment.
[0015] Often, void spaces need to be created in the diaper, such as
holes cut out of the main web for provided leg holes when the
undergarment is ultimately formed. To create the void spaces, the
web is ordinarily die cut, with the web severed between a die and
an anvil. The portion of the web material that is removed is
referred to as a "chip." As the die wears throughout time, the
severing of the chip from the web material becomes gradually a
duller cut. This complicates the removal of the chip because the
severing might not create a continuous cut out chip, with possibly
some strands of the web material still coupling the chip with the
web. It is desired to lengthen the amount of time and increase the
number of chips that a single die can effectively be used for, to
reduce the number of die change-outs.
[0016] The current practice in applying a stretchable web such as a
poly web to a second web involves continuously feeding the poly web
into the process which results in poly running full length of
product, or alternatively, full length of a constructed insert core
which is then placed onto a nonwoven-type chassis. Not all machine
configurations can be adapted from a full length poly chassis to a
poly insert configuration due to space and/or cost restrictions. It
should be understood that application of the poly web along the
entire length of the product, rather than only where it is useful,
increases the amount of poly material which must be utilized. This
is a waste of the material resource and adds additional cost to the
product. It is therefore desirable to create a lower cost product
by putting stretchable material into the product only where it is
useful, instead of the complete product.
[0017] This invention relates to the art of vacuum wheels and more
particularly to a vacuum wheel vacuum opening configuration that
has improved vacuum holding power to hold articles in place.
[0018] A vacuum wheel in the form of a rotary member having vacuum
holes opening onto a cylindrical outer surface for the support and
retention of stretchable film is typically a component of an
apparatus that is known for various applications. A common example
where an apparatus including a vacuum wheel would be used includes
the construction of apparel that is worn on the body such as
disposable diapers. In this application, an elastic waistband is
stretched before being inserted into the waistband region. An
example of such an apparatus is described in U.S. Pat. No.
4,925,520, commonly owned by the assignee hereof and incorporated
herein by reference.
[0019] Absorbent articles including bandages, disposable diapers,
and sanitary napkins, generally include an absorbent core that has
a multiplicity of components so as to improve the article's ab
sorption and retention characteristics.
[0020] Typically, the absorbent fibrous material is composed of
cellulose wadding or cellulosic wood pulp material commonly
referred to as "fluff", although a mixture of natural and synthetic
fibers is within the scope of the invention. An absorbent core
composed of wood pulp fluff is typically formed by employing
conventional air laying techniques.
[0021] These absorbent cores have had their total absorbency
improved greatly by the addition of super absorbent material, or
super absorbent polymer (SAP) to the commonly used absorbent
fibrous materials.
[0022] The ability of these absorbent cores to manage the typical
surges of liquid flow is heavily dependent on the proper
distribution of super absorbent material within the absorbent
fluff. When most super absorbent materials absorb aqueous fluids,
they swell substantially, often to double their dry dimensions or
more at saturation. As these super absorbent materials absorb fluid
and swell, they generally become a gelatinous mass.
[0023] There has been a trend in reducing the bulk of diapers, in
attempts to make them more like underwear and to take up less shelf
space in retailer's outlets. Generally, the thinner the diaper, the
higher the concentration of super absorbent material required to
produce the same level of absorbency. High levels of super
absorbent material, however, tend to be more difficult to control
and to maintain in position.
[0024] In conventional core forming processes, three-dimensional
fluff receiving pockets rotate about a vacuum drum. The pockets
typically include baffles and screens which permit airflow through
the pockets. The fluff is applied to the fluff receiving pockets
entrained in air applied to the pockets. The vacuum attracts the
fluff to a screen-like mesh that forms the pockets. The fluff is
retained by the pockets, and the amount of fluff builds up from the
screen forming the pocket. However, some fluff passes through the
screen of the pockets and into the vacuum stream that is drawing
the fluff into the pocket. Thus, some fluff undesirably becomes
entrained in the vacuum stream.
[0025] In the core forming process, it is required to balance the
amount of air urging the fluff towards the core forming pocket and
the amount of vacuum used to retain the fluff within the pocket.
Machine processes have become more complex as speeds of machines
have increased, so air handling systems used in this process have
greater demands placed on them. For instance, if the machine is
running faster, pulp is required to be delivered to the core
forming pocket quicker, necessitating a greater air flow to the
pocket. To deliver more pulp to the pocket, more vacuum is required
to retain the pulp within the pocket. One complication is in
achieving optimum balance between air in to the pocket and vacuum
applied to the back side of the pocket.
[0026] Imbalance between the amount of air supplying pulp to the
core forming pocket and vacuum applied to the back of the pocket,
holding the fluff in, causes puffs of fluff to escape forming
chamber. Conventional core forming technology allows for limited
adjustability to try and achieve the optimum balance between air in
and vacuum. The largest air delivery is from fiberizing mill which
supplies fluff and blows the fluff into the core forming
chamber.
[0027] Another source of air into forming process is from the dust
collection equipment, which returns collected fluff from the vacuum
stream to the core forming drum. Beginning with fluff that passes
through the core forming pocket, the vacuum stream leads the fluff
within the vacuum stream to the dust collection unit. A filter
within the dust collection unit captures this fluff, this fluff is
removed from the filter, and recirculated into the core forming
process. Typically, this vacuum stream is fed into a drum filter
housing, such as described in U.S. Pat. No. 5,679,136, commercial
embodiments of which are available from the Osprey Corporation, and
which is incorporated herein by reference.
[0028] The process of removing dust off of the filter uses a high
volume of air. It must collect all of the dust, and return the
fluff dust to core forming ducting. When the diaper making machine
is stopped, it is undesirable to return fluff to the core forming
process, because the core forming process is on hold until regular
operation resumes. Ordinarily, in a shut down situation, the vacuum
off of the filter in the dust collection unit is still operating,
and collected fluff or dust gets diverted to a main drum filter.
This process forms a closed loop recirculation while machine is
idle. However, components of the system, such as a nozzle fan, end
up beating the recirculated pulp into a fine powder, and this is
undesirable because the powdered fluff lacks fluid retaining
characteristics.
[0029] Other sources of air delivery to the forming chamber include
the SAP delivery system, and air-bleed openings in the forming
chamber itself.
[0030] It is desired to reduce air flow from the dust return system
in order to achieve greater adjustability to try and achieve the
optimum balance between air in and vacuum. It is also desired to
reduce the destruction of recirculated pulp to obtain better fluid
retaining characteristics.
BRIEF DESCRIPTION OF THE INVENTION
[0031] In general terms, the invention comprises several variations
of core formation techniques, including a large and small discrete
core, formed on a screen and combined; a large and small continuous
core, formed on a web; and a single two or three-dimensional core
formed on a screen or formed on a web. Additionally, and pre-made
air-laid web on or in or between or under several core variations
are disclosed. Of course, various combinations of the above methods
and apparatus can be combined to form additional variations.
[0032] This invention relates to a method and apparatus for forming
an absorbent core or cores. More particularly, the present
invention relates to a method and apparatus for withdrawing fibrous
material from a core forming drum, separating the fibrous material
from an air stream, and forming the core from fibrous material and
super absorbent polymers into different configurations. Cores can
be paired together to form a core of different profile, and cores
can be wrapped individually and placed and combined.
[0033] A method of forming an absorbent core comprising forming a
first core having a first fluff layer and a second super absorbent
polymer and fluff mixture layer at a first speed, forming a second
core having a first fluff layer and a second super absorbent
polymer and fluff mixture layer at a second speed, debulking and
scarfing said first and second cores, accelerating the second,
smaller core from the second speed to substantially match the first
speed, and combining the first and second cores is disclosed.
[0034] Said first core can have a contoured figure such as a peanut
shaped figure (FIG. 15), and said second core can a substantially
rectangular figure, and said second core can be smaller than said
first core.
[0035] The combined first and second cores are deposited onto a top
side of a carrier layer traveling at substantially said first
speed.
[0036] The fluff layers and fluff/SAP layers can be alternated, and
either can be placed face down onto said carrier layer.
[0037] One or both of said first or said second cores can be
wrapped with a material layer prior to deposition on said carrier
layer.
[0038] Either the first or the second core can be placed directly
onto the carrier layer. Either of the fluff layers and fluff/SAP
layers of the first or second cores can be placed directly onto the
carrier layer. In one embodiment, the first core is made by a first
forming drum and said second core is made by a second forming drum.
Alternatively, the second core and is made by a first forming drum
and the first core is made by a second forming drum. Still
alternatively, at least one of said first core and said second core
are formed from a pre-made, air-laid material.
[0039] The cores can either be of similar size, or a bigger/smaller
arrangement, and can be similar or different shapes.
[0040] Cores can either be formed on a pocket type core forming
drum, or a single circumferential pocket on a core forming drum can
be used, and then discrete core pieces from a continuous strip of
core material can be severed by a core knife.
[0041] Three dimensional cores are also disclosed, in which the
core has a width, a length, and at least two different heights.
[0042] To summarize the core element variables, the core element
variables can include two dimensional cores (uniform thickness or
height), or three dimensional cores (variable thickness or
height).
[0043] Core layering can be achieved by a full fluff/SAP blend,
providing a first dusting or fluff layer under or over the
fluff/SAP blend, providing a first and second dusting or fluff
layers under and over the fluff/SAP blend, and providing a core
formed of just fluff.
[0044] Next, the cores can be formed on a screen or on a web.
[0045] Next, the cores can be discrete and unwrapped, discrete and
wrapped, discrete and wrapped with the wrap longer than the core
and glued to form a teabag type structure (in this embodiment the
wrap is cut). The cores can also be continuous and unwrapped and
cut, continuous and wrapped and cut, or the cores can be continuous
and continuously wrapped, and both the core and the wrap are
cut.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The drawings illustrate embodiments presently contemplated
for carrying out the invention.
[0047] In the drawings:
[0048] FIG. 1 is a schematic of one embodiment of the present
invention, a large and small discrete core, formed on a screen and
combined, and then passed downstream for further processing;
[0049] FIG. 2 is a front view of a large and small discrete core
forming unit, formed on a screen and combined, and then passed
downstream for further processing;
[0050] FIG. 3 is a side view of a drum for forming a large and
small discrete core, formed on a screen and combined, and then
passed downstream for further processing;
[0051] FIGS. 4A and 4B are plan views of cores formed according to
the present invention;
[0052] FIGS. 5-12 are side views of a core structure deposition and
scarfing operation;
[0053] FIG. 13 is a side view of an assembled core;
[0054] FIG. 14 is a plan view of an assembled core;
[0055] FIG. 15 is a schematic of a second embodiment of the present
invention, a large and small continuous core, formed on a web;
[0056] FIG. 16 is a side view of a large and small discrete core
forming unit, a large and small continuous core, formed on a
web;
[0057] FIG. 17 is a side view of a drum for forming a large and
small continuous core, formed on a web;
[0058] FIGS. 18A and 18B are plan views of a large and small
continuous core, formed on a web formed according to the present
invention;
[0059] FIGS. 19-26 are side views of a scarfing operation;
[0060] FIG. 27 is a side view of an assembled large and small
continuous core;
[0061] FIG. 28 is a plan view of an assembled large and small
continuous core;
[0062] FIG. 29 is a schematic of a third embodiment of the present
invention, a single three-dimensional core formed on a screen, and
then passed downstream for further processing;
[0063] FIG. 30 is a side view of a single three-dimensional core
formed on a screen core forming unit;
[0064] FIG. 31 is a side view of a drum for forming a single
three-dimensional core formed on a screen;
[0065] FIG. 32 is a plan view of a large and small continuous core,
formed on a web formed according to the present invention;
[0066] FIGS. 33-36 are side views of a scarfing operation;
[0067] FIG. 37 is a side view of an assembled single
three-dimensional core formed on a screen;
[0068] FIG. 38 is a plan view of an assembled single
three-dimensional core formed on a screen.
[0069] FIGS. 39-41 describe formation of a dual core, with a
larger, non-wrapped core structure laid upon a poly layer, topped
by a tissue-wrapped small core structure;
[0070] FIG. 39 is a schematic of an alternate embodiment of the
present invention, with a larger, non-wrapped core structure laid
upon a poly layer, topped by a tissue-wrapped small core structure,
and then passed downstream for further processing;
[0071] FIG. 40 is a side view of a large and small discrete core
forming unit, with a larger, non-wrapped core structure laid upon a
poly layer, topped by a tissue-wrapped small core structure, and
then passed downstream for further processing;
[0072] FIG. 41a is a cross sectional view of a larger, non-wrapped
core structure laid upon a poly layer, topped by a tissue-wrapped
small core structure;
[0073] FIGS. 41b and 41c are plan and cross sectional views of an
alternative embodiment of the product shown in FIG. 41a,
respectively;
[0074] FIGS. 42-44 describe formation of a dual core, with a small,
tissue-wrapped core structure laid upon a poly layer, topped by a
non-wrapped larger core structure;
[0075] FIG. 42 is a schematic of an alternate embodiment of the
present invention, with a small, tissue-wrapped core structure laid
upon a poly layer, topped by a non-wrapped larger core structure,
and then passed downstream for further processing;
[0076] FIG. 43 is a side view of a large and small discrete core
forming unit, with a small, tissue-wrapped core structure laid upon
a poly layer, topped by a non-wrapped larger core structure, and
then passed downstream for further processing;
[0077] FIG. 44 is a cross sectional view of a with a small,
tissue-wrapped core structure laid upon a poly layer, topped by a
non-wrapped larger core structure;
[0078] FIG. 45 is a side schematic type view of an alternative
embodiment of the present invention, a machine employing pre-made
air-laid webs introduced into the core forming process;
[0079] FIGS. 46-52 are side views of various core deposition
configurations both with and without introduction of a pre-made
air-laid layer in various positions;
[0080] FIG. 53 is a front view of a large and small discrete core
forming unit, formed on a screen and combined, and then passed
downstream for further processing with optional fluff
introduction;
[0081] FIG. 54 is a cross-sectional view of a possible strata
configuration produced by the machine of FIG. 53;
[0082] FIGS. 55-60 are side views of an alternate core structure
deposition and scarfing operation for creating a first core;
[0083] FIGS. 61-66 are side views of an alternate core structure
deposition and scarfing operation for creating a second core;
[0084] FIGS. 67 and 68 are a cross-sectional and a top view of the
placed formed cores of FIGS. 55-66 respectively.
DETAILED DESCRIPTION
[0085] Although the disclosure hereof is detailed and exact to
enable those skilled in the art to practice the invention, the
physical embodiments herein disclosed merely exemplify the
invention which may be embodied in other specific structures. While
the preferred embodiment has been described, the details may be
changed without departing from the invention, which is defined by
the claims.
[0086] Referring now to FIG. 1, a schematic of one embodiment of
the present invention, a large and small discrete core, formed on a
screen and combined, and then passed downstream for further
processing is shown. As can be seen, two simultaneously operating
core forming units, one big and one small, are used to form a big
core and a small core, both preferably comprised of fluff and SAP.
The small core is accelerated to match the speed of the large core
prior to downstream processing.
[0087] Referring now to FIG. 2, a side view of a large and small
discrete core forming 10 units is shown.
[0088] A small core forming drum 12S (to form small cores) is
first, followed by a big core forming drum 12B (to form big cores).
Both of these drums 12S and 12B receive a first layer of dust or
fluff/SAP mixture 30 from Fluff/SAP introduction unit 16, onto a
pocketed drum 12S or 12B, shown in side view in FIG. 3. Processes
on the drums can include fluff and sap deposition, scarfing, fluff
deposition, and another scarfing operation. The core can be scarfed
by scarfing unit 14, which discharges and recycles the scarfed
material back into the system through discharge 14D. Next, an
additional layer of fluff 28 from fluff introduction unit 18 is
applied atop the SAP/Fluff mixture. One purpose of the addition of
an independent fluff layer 28 is to isolate SAP from contacting
unintended surfaces, because the SAP can have a tendency to be
abrasive and migrate. This sequence is depicted in FIGS. 5-8 for
formation of the big core 26B, and FIGS. 9-12 for formation of the
small core 26S. In FIGS. 5-8, a SAP/Fluff mixture 30 is first
deposited (FIG. 5), and scarfed by scarfing unit (FIG. 6), next a
fluff layer 28 is deposited and scarfed (FIGS. 7a and 7b) and then
deposited onto running web 120 (FIG. 8).
[0089] The big core forming drum 12B deposits a big core 26B onto a
conveyor 24 following debulking unit 20 (FIG. 4a), and after being
carried downstream, it receives, after an optional scarfing unit
14, the small core 26S which can be passed through debulking unit
20 and then to a core acceleration unit 22 to match speeds with the
big core 26B (FIG. 4B).
[0090] Referring to FIGS. 13 and 14, a side and top view of an
assembled core 26 is shown. As can be seen, the core comprises
essentially four layers: the small core 26s having a SAP/Fluff
mixture 30 on top, and a fluff layer 28, the large core 26B
likewise having a SAP/Fluff mixture 30 on top, and a fluff layer
28. This assembled core is then passed downstream for further
processing as desired. As can be seen in FIG. 14, in one embodiment
the core 26B is contoured in a peanut-shaped configuration.
[0091] Referring now to FIG. 15, a schematic of a second embodiment
of the present invention is shown, a large and small continuous
core, both formed on a web.
[0092] Referring now to FIG. 16, a side view of a large and small
discrete core forming unit, a large and small continuous core,
formed on a web is shown. The first step in the sequence of
formation of both the big and small cores is introduction of a
non-woven web 50. Atop this layer is applied fluff 28 by fluff
introduction unit 18. Next, SAP/fluff mix 30 is applied through the
SAP/Fluff introduction system 40. An optional scarfing unit 14 can
be used (recycled scarf material recycled through scarf recycling
pathway 14D), followed by a debulking unit 20. As can be seen in
FIG. 17, the drums 12B and 12S of this system can have a continuous
pocket for forming a running web of continuous core material (cut
to discrete core pieces by a core knife, described later). As shown
in FIGS. 18A and 18B, plan views of a big and small continuous core
46B and 46S respectively are so formed. The scarfing operations of
FIGS. 19-26 are side views of a scarfing operation which are
optionally used on the uncovered sides of the cores 46B and 46S. A
core is formed as shown in FIGS. 27 and 28, essentially to
individually wrapped cores 46B and 46S.
[0093] During formation of the small core 46S, the continuous core
is cut after formation using anvil/knife unit 46, and speed matched
by rotating drum 44 and applied atop continuous web 46B. The
continuous web 46B (now carrying severed small cores 46S) is then
cut with knife 42, completing formation of the discrete cores 46
for further downstream processing.
[0094] Referring now to FIG. 29, a schematic of a third embodiment
of the present invention, a single two or three-dimensional core
formed on a screen (and/or formed on web), and then passed
downstream for further processing is shown.
[0095] In this embodiment, as shown in FIG. 30, a side view of a
single three-dimensional core formed on a screen core forming unit,
a first fluff layer 28 from the fluff introduction unit 18 is
deposited onto the drum 12 (with a three dimensional pocket, FIG.
31), followed by SAP/Fluff mixture 30 through introduction unit
16/18. Scarfing unit 14 is employed followed by a transfer roll 20,
(debulking/embossing, or two debulking units, and an optional knife
42). The scarfing unit 14 of this embodiment could scarf outer
boundaries of the composite core 56 (FIG. 32), or a debulker could
compress the shape by a pocket component to result in the
three-dimensional, two layer profile shown in FIG. 37 (shown in
plan on FIG. 38). In the embodiment of FIGS. 37 and 38, the cores
have identical lengths (from top to bottom). The bottom core has a
larger width (side to side), but the top core can have at least two
different heights (seen in FIG. 37) to form a three dimensional
core.
[0096] In summary, either a one drum or a two drum unit can be
employed to form cores of the present invention. The drums can be
either shaped, homogenous, and a dust layer can be employed where
desired. A form-on tissue method can be employed for either the
small core, the large core, a single wrap or both. Debulking and
placing can also be combined as desired to form a desired core.
[0097] Referring now to FIGS. 39-41a, formation of a dual core,
with a larger, non-wrapped core structure laid upon a poly layer,
topped by a tissue-wrapped small core structure is described.
[0098] Referring specifically to FIG. 39, a schematic of an
alternate embodiment of the present invention is shown, with a
larger, non-wrapped core structure laid upon a poly layer, topped
by a tissue-wrapped small core structure, and then passed
downstream for further processing.
[0099] FIG. 40 is a side view of a large and small discrete core
forming unit to perform the methods described in FIG. 39. Both of
these drums 12S and 12B receive a first layer of dust or fluff/SAP
mixture 30 from Fluff/SAP introduction unit 16, onto a pocketed
drum 12S or 12B, shown in side view in FIG. 3. The core can be
scarfed by scarfing unit 14, which discharges and recycles the
scarfed material back into the system through discharge 14D. Next,
an additional layer of fluff 28 from fluff introduction unit 18 is
applied atop the SAP/Fluff mixture.
[0100] The big core forming drum 12B deposits a big core 26B onto a
conveyor 24 following debulking unit 20, and after being carried
downstream, it receives, after an optional scarfing unit 14, the
small core 26S which can be passed through debulking unit 20 and
then to a core acceleration unit 22 to match speeds with the big
core 26B. Debulking unit 20, as shown in FIG. 40, can comprise a
first debulking component 20a, a second embossing unit 20b, and a
third core knife station 20c. In this embodiment, the small core 26
is wrapped with a two-piece wrap comprising a first, base tissue
114 fed onto the drum 12S onto which the core 26S is formed. After
coming off of the core forming unit 12S and onto conveyor 24, a
second, upper tissue 112 is applied to the core 26S by tissue
applicator 110, preferably in the manner shown in cross-sectional
view in FIG. 41a. The core 26s can be cut on a third station shown
schematically at unit 20. The wrapped small core 26S is then
deposited on top of the larger, non-wrapped core 26B, and the two
cores 26S and 26B are deposited onto incoming poly layer 116,
combined by compression unit 118, resulting in a cross-sectional
two piece core as shown in FIG. 41a.
[0101] Referring to FIGS. 41b and 41c, plan and cross sectional
views of an alternative embodiment of the product shown in FIG.
41a, respectively are shown. In this embodiment, a margin 250 is
glued, to close the ends of the tissue wrap 114, to create a
tea-bag type structure.
[0102] Referring now to FIGS. 42-44, an alternate embodiment of a
dual core structure is shown, with a small, tissue-wrapped core
structure laid upon a poly layer, topped by a non-wrapped larger
core structure.
[0103] FIG. 42 is a schematic of machinery to perform this
alternate embodiment of the present invention, with a small,
tissue-wrapped core structure laid upon a poly layer, topped by a
non-wrapped larger core structure, and then passed downstream for
further processing.
[0104] Referring now to FIG. 43, a side view of a small (wrapped)
and large discrete core forming unit to perform the methods
described in FIG. 39 is shown. Again, both of the drums 12S and 12B
receive a first layer of dust or fluff/SAP mixture 30 from
Fluff/SAP introduction unit 16, onto a pocketed drum 12S or 12B,
shown in side view in FIG. 3. The core can be scarfed by scarfing
unit 14, which discharges and recycles the scarfed material back
into the system through discharge 14D. Next, an additional layer of
fluff 28 from fluff introduction unit 18 is applied atop the
SAP/Fluff mixture.
[0105] The small core forming drum 12S deposits a small, wrapped
core 26S onto a conveyor 24 following debulking unit 20, and after
being carried downstream, it receives, after an optional scarfing
unit 14, the small core 26S which can be passed through debulking
unit 20 and then to a core acceleration unit 22 to match speeds
with the big core 26B.
[0106] In this embodiment, the small core 26 is wrapped with a
two-piece wrap comprising a first, base tissue 114 fed onto the
drum 12S onto which the core 26S is formed. After coming off of the
core forming unit 12S and onto conveyor 24, a second, upper tissue
112 is applied to the core 26S by tissue applicator 110, preferably
in the manner shown in cross-sectional view in FIG. 43. The large
core 26S is then deposited on top of the smaller, wrapped core 26S,
and the two cores 26S and 26B are deposited onto incoming poly
layer 116, combined by compression unit 118, resulting in a
cross-sectional two piece core as shown in FIG. 44.
[0107] Referring now to FIG. 45, a side schematic type view of an
alternative embodiment of the present invention, a machine
employing pre-made air-laid webs introduced into the core forming
process. Pre-made air-laid webs 216, 218, and 220 can be introduced
into the core forming process in various configurations, as
depicted in FIGS. 46-52.
[0108] Referring to FIG. 45, a first, discrete core forming drum
210 is shown, similar to previously described core forming drums. A
continuous core forming drum 212 can be provided with a tissue wrap
114 to wrap the formed core. A first debulking component 20a, a
second embossing unit 20b, and a third core knife station 20c are
together used to process the continuous core prior to placement
atop the previously formed discrete core.
[0109] Referring to FIGS. 46-52, various core deposition
configurations both with and without introduction of a pre-made
air-laid layer in various positions are shown. In FIG. 46, small
core 26S is wrapped by core wrap 114, and carried by large core
26B, which is carried by poly layer 230 and backsheet 234, which
together sandwich crotch elastics 232.
[0110] Referring to FIG. 47, a first pre-made air-laid web 220
(provided by the unit shown in FIG. 45) replaces small core 26S,
and this web 220 serves as the small core.
[0111] Referring to FIG. 48, a pre-made air-laid layer 218
(provided by the unit shown in FIG. 45) is provided atop a small
core 26S wrapped by wrap 114.
[0112] Referring to FIG. 49, both a pre-made air-laid layer 216
(provided by the unit shown in FIG. 45) and small core 26S can be
wrapped by wrap 114 and placed atop large core 26B. Small core 26S
can comprise either just fluff material 28, or a layered core as
described previously.
[0113] Referring to FIG. 50, small core 26S can be wrapped with
tissue 114, carried by core 26B, which can in turn be carried by
pre-made air-laid layer 218 (provided by the unit shown in FIG.
45).
[0114] Referring to FIG. 51, pre-made air-laid layer 218 (provided
by the unit shown in FIG. 45) can be carried by wrapped small core
26, carried by core 26B, carried by a second pre-made air-laid
layer 220 (provided by the unit shown in FIG. 45).
[0115] Referring to FIG. 52, wrapped small core 26 can be carried
by pre-made air-laid layer 218 (provided by the unit shown in FIG.
45), which can in turn be carried by core 26B, carried by a second
pre-made air-laid layer 220 (provided by the unit shown in FIG.
45).
[0116] Referring now to FIG. 53 is a front view of a large and
small discrete core forming unit similar to that shown in FIG. 2.
In this embodiment, additional optional fluff layers 28 can be
incorporated to result in cores with cross-sections as shown in
FIG. 54.
[0117] Referring now to FIGS. 55-60, side views of an alternate
core structure deposition and scarfing operation for creating a
first core are shown. In this embodiment, a first fluff layer 28 is
deposited, next a fluff/SAP mixture 30 is provided and scarfed, and
next a second fluff layer 28 is deposited and scarfed, to result in
the small core 26S with the configuration shown in FIG. 60 A
similar process is shown in FIGS. 61-66 for creating a second core
26B.
[0118] FIGS. 67 and 68 are a cross-sectional and a top view of the
placed formed cores 26S and 26B of FIGS. 55-66.
[0119] The foregoing is considered as illustrative only of the
principles of the invention. Furthermore, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without
departing from the invention, which is defined by the claims.
* * * * *