U.S. patent application number 11/285454 was filed with the patent office on 2007-05-24 for sheet slitting forming belt for nonwoven products.
Invention is credited to Jean-Louis Monnerie, Remy Trubacz.
Application Number | 20070116928 11/285454 |
Document ID | / |
Family ID | 37771047 |
Filed Date | 2007-05-24 |
United States Patent
Application |
20070116928 |
Kind Code |
A1 |
Monnerie; Jean-Louis ; et
al. |
May 24, 2007 |
Sheet slitting forming belt for nonwoven products
Abstract
A forming fabric for use in the production of nonwoven products
comprising a plurality of protuberances having a predetermined size
and shape, wherein the protuberances are arranged in a pattern that
defines a size and shape of nonwoven sheets formed therefrom.
Inventors: |
Monnerie; Jean-Louis;
(Saint-Junien, FR) ; Trubacz; Remy;
(La-Ferriere-Au-Doyen, FR) |
Correspondence
Address: |
FROMMER LAWRENCE & HAUG
745 FIFTH AVENUE- 10TH FL.
NEW YORK
NY
10151
US
|
Family ID: |
37771047 |
Appl. No.: |
11/285454 |
Filed: |
November 22, 2005 |
Current U.S.
Class: |
428/147 ;
427/294; 428/105; 442/152; 442/164; 442/172 |
Current CPC
Class: |
Y10T 442/30 20150401;
D04H 1/495 20130101; Y10T 442/2861 20150401; D04H 3/16 20130101;
D04H 1/56 20130101; Y10T 428/24058 20150115; Y10T 428/24281
20150115; Y10T 442/2926 20150401; D04H 3/02 20130101; D21F 11/006
20130101; D04H 1/732 20130101; D04H 3/07 20130101; Y10T 442/2762
20150401; Y10T 428/24405 20150115 |
Class at
Publication: |
428/147 ;
442/152; 442/164; 442/172; 428/105; 427/294 |
International
Class: |
D06N 7/04 20060101
D06N007/04 |
Claims
1. A forming fabric for use in the production of nonwoven products
comprising a plurality of protuberances having a predetermined size
and shape, wherein said protuberances are arranged in a pattern or
grid and wherein said pattern defines a size and shape of nonwoven
sheets formed therefrom.
2. The forming fabric as claimed in claim 1, wherein said fabric is
woven or nonwoven.
3. The forming fabric as claimed in claim 1, wherein said plurality
of protuberances are on a web forming side of said forming
fabric.
4. The forming fabric as claimed in claim 1, wherein said plurality
of protuberances are impermeable to air.
5. The forming fabric as claimed in claim 1, wherein said plurality
of protuberances are formed of a polymeric resin material.
6. The forming fabric as claimed in claim 5, wherein said polymeric
resin material is selected from the group consisting of polyamide,
polyester, polyetherketone, polypropylene, polyolefin;
polyurethane, polyketone, and polyethylene terephthalate
resins.
7. The forming fabric as claimed in claim 1, wherein said plurality
of protuberances are formed of a thermoplastic material, silicone
or rubber.
8. The forming fabric as claimed in claim 1, wherein said plurality
of protuberances are individual strips or pieces of material.
9. The forming fabric as claimed in claim 8, wherein said plurality
of protuberances are attached to said forming fabric.
10. The forming fabric as claimed in claim 9, wherein said
plurality of protuberances are attached to said forming fabric
using a mechanical attachment means selected from the group
consisting of gluing with an adhesive, melt bonding, stitching and
hook and loop fastening.
11. The forming fabric as claimed in claim 1, wherein said
plurality of protuberances are formed as a coating, an extrusion or
as a resin deposition.
12. The forming fabric as claimed in claim 1, wherein said
plurality of protuberances have a cross-sectional shape selected
from the group consisting of square, triangular, rectangular and
rectangular having chamfered corners.
13. A method of forming individual nonwoven sheets comprising the
steps of: providing an air permeable forming fabric; selectively
closing a plurality of areas on said forming fabric to air flow in
a desired pattern or grid on a web forming surface of said forming
fabric; providing a vacuum means adjacent to a non-web forming side
of said forming fabric; depositing fibers on said forming fabric;
and wherein said pattern defines a size and shape of the individual
nonwoven sheets formed on said forming fabric.
14. The method as claimed in claim 13, wherein the forming fabric
is woven or nonwoven.
15. The method as claimed in claim 13, wherein said vacuum means
provides a suction to the forming fabric thereby urging said fibers
onto air permeable areas of said forming fabric.
16. The method as claimed in claim 13, wherein said plurality of
areas on said forming fabric are rendered impermeable to air with
the addition of an impermeable material to said web forming surface
of said forming fabric.
17. The method as claimed in claim 16, wherein said impermeable
material is formed of a polymeric resin material.
18. The method as claimed in claim 17, wherein said polymeric resin
material is selected from the group consisting of polyamide,
polyester, polyetherketone, polypropylene, polyolefin,
polyurethane, polyketone, polyethylene terephthalate resins.
19. The method as claimed in claim 16, wherein said impermeable
material is formed of a thermoplastic material, silicone or
rubber.
20. The method as claimed in claim 13, wherein said pattern or grid
is constructed from individual strips or pieces of impermeable
material.
21. The method as claimed in claim 20, wherein said individual
strips or pieces of impermeable material are attached to said
forming fabric.
22. The method as claimed in claim 21, wherein said individual
strips or pieces of impermeable material attach to said forming
fabric using a mechanical attachment means selected from the group
consisting of gluing with an adhesive, melt bonding, stitching and
hook and loop fastening.
23. The method as claimed in claim 18, wherein said impermeable
material is formed as a coating, an extrusion or as a resin
deposition.
24. The method as claimed in claim 16, wherein said impermeable
material has a cross-sectional shape selected from the group
consisting of square, triangular, rectangular, and rectangular
having chamfered corners.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The instant invention relates generally to the production of
nonwoven products. More specifically, the instant invention relates
to a forming fabric or belt for use in the manufacture of
nonwovens.
[0003] 2. Background of the Invention
[0004] The production of nonwoven products is well known in the
art. Nonwoven products are used in a wide variety of applications
ranging from baby diapers to high performance textiles where the
engineered qualities of the products can be advantageously
employed. Numerous nonwoven products can be manufactured using the
instant invention including, but not limited to: geotextiles;
building materials such as MDF (medium density fiberboard), roofing
and tile underlayment, acoustic ceiling tiles and thermal and sound
insulation; hygienic and healthcare products such as bandages,
tapes, sterile packaging, diapers and sanitary napkins; and
household goods such as wipes, scouring pads, fabric softener
sheets, placemats, napkins, washcloths, tablecloths and vacuum
bags. In these types of products, the fibers or filaments of the
product are integrated into a coherent web. Entanglement of the
fibrous elements of the nonwoven web, coupled with other processes
such as chemical or thermal bonding, provides the desired product
integrity, functionality and aesthetics.
[0005] Such products are produced directly from fibers without
conventional textile methods such as weaving or knitting
operations. Instead, they are produced by nonwoven manufacturing
methods and processes such as meltblowing. In the meltblown process
for manufacturing nonwoven products, a thermoplastic forming
polymer is placed in an extruder and is then passed through a
linear die containing about twenty to forty small orifices per inch
of die width. Convergent streams of hot air rapidly attenuate the
extruded polymer steams to form solidifying filaments. The
solidifying filaments are subsequently blown by high velocity air
onto a take-up screen or another layer of woven or nonwoven
material thus forming a meltblown web.
[0006] In addition, nonwoven products may be produced by air-laying
or carding operations where the web of fibers is consolidated or
processed, subsequent to deposition, into a nonwoven product by
needling or hydroentanglement. In the latter, high-pressure water
jets are directed vertically down onto the nonwoven web to entangle
the fibers with each other. In needling, entanglement is achieved
mechanically through the use of a reciprocating bed of barbed
needles which force fibers on the surface of the web further
thereinto during the entry stroke of the needles.
[0007] Nonwoven products are generally made up of fibers locked
into place by fiber interaction to provide a strong cohesive
structure, with or without the need for chemical binders or
filament fusing. The products may have a repeating pattern of
entangled fiber regions of higher area density (weight per unit
area) than the average area density of the product, and
interconnecting fibers which extend between the densely entangled
regions that are randomly entangled with each other. Localized
entangled regions may be interconnected by fibers extending between
adjacent entangled regions to define regions of lower area density
than that of the adjacent high-density region. A pattern of
apertures substantially free from fibers may be defined within or
between the dense entangled regions and interconnecting fibers.
Unlike in the instant invention, however, these patterns are not
used to separate the nonwoven web into a plurality of individual or
separate nonwoven sheets.
[0008] In some products, the densely entangled regions are arranged
in a regular pattern and joined by ordered groups of fibers to
provide a nonwoven product having an appearance similar to that of
a conventional woven fabric, but in which the fibers proceed
randomly through the nonwoven product from entangled region to
entangled region. The fibers of an ordered group may be either
substantially parallel or randomly disposed relative to one
another. Embodiments include nonwoven products having complex fiber
structures with entangled fiber regions interconnected by ordered
fiber groups located in different thickness zones of the nonwoven,
which are particularly suitable for apparel and industrial products
such as wipes.
[0009] As previously stated, the nonwoven web may be processed and
the fibers locked into place in the product by fiber interaction.
By "locked into place," it is meant that individual fibers of the
structure not only have no tendency to move from their respective
positions in the patterned structure, but they are actually also
physically restrained from such movement by interaction with
themselves and/or with other fibers of the product. Fibers are
locked into place in the entangled fiber regions of higher area
density than the average area density of the product, and such
fiber interaction may also occur elsewhere.
[0010] By "interaction," it is meant that the fibers turn, wind,
twist back-and-forth and pass about one another in all directions
of the structure in such an intricate entanglement that they
interlock with one another.
[0011] Mechanical entanglement processes such as needling, bind or
secure a layer or layers of fibers to themselves or to a substrate
by impaling the fibrous webs with a large number of barbed needles
in a device called a needle loom or fiber locker. This action
pushes fibers from the fiber layer surface into and through the
bulk of the web layers. While strength properties are improved by
this entangling of fibers within the web, the process can be slow,
the needles can damage the fibers, and the needles themselves are
worn out rapidly.
[0012] In order to avoid these problems, hydroentangling (or
"spunlacing") processes have been developed which use the energy of
small-diameter, highly coherent jets of high-pressure water to
mimic the entangling action of the older needle loom. The process
involves forming a fiber web as described above, after which the
fibers are entangled by means of very fine water jets under high
pressure. Several rows of water jets are directed against the fiber
web which is supported by a movable wire or fabric. The entangled
fiber web is then dried. The fibers that are used in the material
can be synthetic or regenerated staple fibers, e.g. polyester,
polyamide, polypropylene, rayon or the like, cellulose or other
material fibers or mixtures of any combination of these materials.
Spunlace materials can be produced in high quality at a reasonable
cost and have a high absorption capacity. They can be used as
wiping materials for household or industrial use, as disposable
materials in medical care and for hygiene purposes, etc.
[0013] The hydroentangling process can be used to produce a large
number of different products by varying the initial material and/or
the belt/patterning member used. The initial material may consist
of any web, mat, batt or the like of loose fibers disposed in
random relationship with one another or in any degree of alignment.
The term "fiber" as employed herein, is meant to include all types
of fibrous material, whether naturally or synthetically produced,
and comprises, for example, fibrids (of a type of synthetic fibrous
particles used in bonding), cellulose fibers, and textile staple
fibers. Improved properties can be obtained by suitable
combinations of different lengths of fibers. Reinforced products
are provided by combinations of staple length fibers with fibrous
strands, where the term "strands" includes filaments and various
forms of conventional textile fibers, which may be straight or
crimped, and other desirable products are obtained by using highly
crimped and/or elastic fibers in the initial material. Particularly
desirable patterned, nonwoven products are prepared by using an
initial material comprising fibers having a latent ability to
elongate, crimp, shrink, or otherwise change in length, and
subsequently treating the patterned, nonwoven structure to develop
the latent properties of the fibers so as to alter the free-length
of the fibers. The initial material may contain different types of
fibers, e.g., shrinkable and nonshrinkable fibers, to obtain
special effects upon activation of the latent properties of one
type of fiber.
[0014] In addition, thermal bonding can be used to lock the fibers
in the nonwoven product into place. With thermal bonding, a binding
material is necessary in order to bind the nonwoven fibers to each
other. Binding materials include binding fibers, binding powders
and binding webs. Binder fibers are the most widely used in thermal
bonding and include single-component and bi-component fibers. When
heat is applied, portions of the binder fibers melt, thereby
binding with other fibers at the fiber cross-over points. Binding
powders in the form of powdered polymers are also used to bind the
fibers to each other. The binding powders are applied between
layers of fibers during cross-laying, air-laying or as an after
treatment. With binding powders, a short exposure to heat in an
oven is usually sufficient to melt and fuse the powder to the
nonwoven fibers resulting in a nonwoven web comprised of fibers
that are bound to each other. Lastly, a binding web, which is a
low-melting point, thermoplastic open-structured fabric, can be
placed between the nonwoven webs. In order to bind the nonwoven
webs together, heat is applied to completely melt the binding web
and calendar rolls are used to press and bind the nonwoven webs
together. Methods of thermal binding include, for example, hot
calendaring, belt calendaring, oven bonding, ultrasonic bonding and
radiant heat bonding. The bonding method used has a significant
effect on product properties such as porosity, thickness and
absorbency. All bonding methods, however, provide strong bond
points that are resistant to hostile environments and to many
solvents.
[0015] In all of the previously described methods and processes
used to produce nonwoven products, an endless forming fabric or
belt plays a key role in the formation of the nonwoven web.
Generally, these belts take the form of mesh screens woven from
plastic monofilaments, although metal wire may be used instead of
plastic monofilaments when temperature conditions during a nonwoven
manufacturing process make it impractical or impossible to use
plastic monofilament.
[0016] While each of these methods of manufacturing and processing
of nonwoven products has its advantages, all current manufacturing
systems require additional processing to cut or separate the
nonwoven web into the desired sizes and shapes of the final
nonwoven product. The instant invention is directed to overcoming
this shortcoming of the known systems.
SUMMARY OF THE INVENTION
[0017] It is therefore a principal object of the invention to
provide a forming fabric or belt for use in the manufacture of
nonwoven products that reduces post processing of the nonwoven web
by eliminating the step of cutting or slitting the nonwoven web
into smaller, individual nonwoven sheets.
[0018] It is a further object of the invention to provide a forming
fabric or belt for use in the manufacture of nonwoven products
capable of cutting or dividing the nonwoven web formed thereon
during the forming process.
[0019] Yet another object of the invention is to provide a forming
fabric or belt used in the manufacture of nonwoven products having
an impermeable material applied as a coating, an extrusion, a
deposition, or as individual strips or pieces of material attached
to the surface of the web forming side of the fabric or belt that
cuts or slits the nonwoven web into individual, separate nonwoven
sheets.
[0020] A still further object of the invention is to provide a
method of forming a plurality of individual nonwoven sheets on a
forming fabric or belt used in the manufacture of nonwoven
products.
[0021] These and other objects and advantages are provided by the
instant invention. In this regard, the instant invention is
directed to a forming fabric that is used in the production of
nonwoven products. In a preferred embodiment, the forming fabric
comprises a plurality of protuberances that are included on the web
forming side of the forming fabric. The plurality of protuberances
are arranged in a pattern or grid and define the size and shape of
nonwoven sheets formed thereon. The protuberances are constructed
from an air impermeable material that includes polymeric resins and
thermoplastic materials, for example.
[0022] Another aspect of the instant invention is a method of
forming individual nonwoven sheets. The method includes providing
an air permeable forming fabric. A plurality of areas on the web
forming surface of the air permeable forming fabric are selectively
closed to air in a desired pattern or grid, wherein the desired
pattern or grid defines the shape and size of the individual
nonwoven sheets formed thereon. Vacuum boxes are provided adjacent
to the non-web forming surface of the air permeable forming fabric
in order to provide suction to the forming fabric, thereby urging
the fibers deposited onto the forming fabric toward the air
permeable areas of the fabric. The plurality of areas on the
forming belt are rendered impermeable to air by the addition of an
impermeable material to the web forming surface of the forming
fabric, such as polymeric resins or thermoplastic materials, for
example.
[0023] The various features of novelty which characterize the
invention are pointed out in particularity in the claims annexed to
and forming a part of this disclosure. For a better understanding
of the invention, its operating advantages and specific objects
attained by its uses, reference is made to the accompanying
descriptive matter in which preferred embodiments of the invention
are illustrated in the accompanying drawings in which corresponding
components are identified by the same reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The following detailed description, given by way of example
and not intended to limit the present invention solely thereto,
will best be appreciated in conjunction with the accompanying
drawings, wherein like reference numerals denote like elements and
parts, in which:
[0025] FIG. 1 is a forming fabric of the instant invention
installed on an apparatus used to manufacture nonwoven
products;
[0026] FIG. 2 depicts a shape and configuration of manufactured
nonwoven products, according to one embodiment of the instant
invention; and
[0027] FIGS. 3A-3E depict various cross-sectional shapes for the
impermeable material, according to one embodiment of the instant
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The instant invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the illustrated embodiments set forth
herein. Rather, these illustrated embodiments are provided so that
this disclosure will be thorough and complete, and will fully
convey the scope of the invention to those skilled in the art.
[0029] The instant invention relates to a forming fabric or belt
used to manufacture slitted or individual nonwoven sheets. As used
herein, the terms fabric and belt are used interchangeably.
Additionally, the term "web" refers to a nonwoven product formed on
a forming fabric. Lastly, a "sheet" as used herein defines any
nonwoven product that has dimensions less than the dimensions of
the web forming area on the forming fabric upon which it is
formed.
[0030] Typically, a nonwoven web is formed on a forming fabric and
requires additional processing to cut or slit the nonwoven web into
smaller, individual sheets. The instant invention eliminates post
processing cutting or slitting of the formed nonwoven web since use
of the instant forming fabric results in separate, individual
nonwoven sheets being formed directly on the fabric during the web
forming stage of the manufacturing process.
[0031] The instant invention achieves slitted or individualized
nonwoven sheets by obtaining a different fiber distribution
directly on the forming fabric in, for example, airlaid, meltblown,
or spunlace nonwoven manufacturing processes.
[0032] As depicted in FIG. 1, an air permeable forming fabric 10
used in the manufacturing of nonwoven product, having machine
direction (MD) and cross machine direction (CD) yarns, such as
disclosed in pending U.S. Application entitled "High-Speed
Spun-Bond Production of Nonwoven Fabrics" Ser. No. 10/280,865,
(U.S. 2003/0164199) the disclosure of which is incorporated herein
by reference. The fabric 10 includes an impermeable material 15 in
the form of a pattern or grid 20 on the web forming surface 25 of
the forming fabric 10. It should be noted that the fabric may be
woven from yarns, fibers, threads, strands or the like, and that
the term "yarns" as used herein is meant to collectively refer to
all such elements. Furthermore, the yarns may be of a synthetic or
natural material such as metal. Additional structures may be used
as the forming fabric substrate, for example, an extruded mesh, a
knitted fabric, MD or CD yarn arrays, or other structures suitable
for the purpose.
[0033] The material used to form the pattern or grid 20 on the
forming fabric 10 must be impermeable to air. By having areas on
the forming fabric 10 that are impermeable to air, fibers that are
deposited on the fabric during one of the previously discussed
nonwoven manufacturing processes, are drawn by negative airflow or
suction created by vacuum boxes located on the non-web forming side
of the forming fabric 10, to the areas of the fabric that are
permeable to air. As a result, the fibers that are deposited on the
fabric accumulate on the air permeable areas of the fabric and not
on the areas of the fabric that have been made impermeable with the
addition of the impermeable material. Because the fibers on either
side of the air impermeable areas of the fabric are isolated from
one another and hence do not interact with each other, these
portions of the nonwoven web are prevented from becoming entangled
with one another during one of the previously described entangling
methods. After the fibers are deposited onto the belt, the fibers
are locked into place using one of the previously disclosed
processes. The result is a nonwoven web that is already separated
or slit into individual nonwoven pieces 30.
[0034] As depicted in FIG. 1, gaps 35 are formed between the
individual nonwoven sheets in the areas that correspond to the
areas of the forming fabric 10 that have been rendered impermeable
to form the pattern or grid 20. It should be noted that the
impermeable material can be applied to the fabric surface as a
coating using any of the methods well known in the art or the
material can be deposited via extrusion or the material can be
deposited via a process as described in commonly assigned,
copending application, U.S. patent application entitled "Method of
Fabricating a Belt and a Belt Used to Make Both Tissue and Towels
and Nonwoven Articles and Fabrics", Ser. No. 10/334,211 (U.S.
2004/016601 A1), the contents of which are incorporated herein by
reference. The impermeable material can also be applied in the form
of strips or pieces of material having various shapes and sizes and
that are attached to the web forming side of the fabric using any
mechanical attachment means known to those skilled in the art,
including, but not limited to coatings, gluing with an adhesive,
stitching, melt bonding or with the use of hook and loop type
fasteners, i.e. VELCRO.RTM..
[0035] In one embodiment of the instant invention, as can be seen
in FIG. 2, the individual nonwoven sheets 34 that are formed using
the instant forming fabric are defined by X and Y dimensions. These
dimensions define the areas on the fabric between the impermeable
material on the surface of the belt. The width of the gaps 35
between the individual nonwoven sheets is dependent on the width of
the impermeable material that is attached or applied to the surface
of the belt 25. Therefore, various sizes and shapes of the
individual nonwoven sheets, within the dimensions of the forming
fabric, can be manufactured by varying the size and/or shape of the
pattern or grid formed on the belt surface by the impermeable
material. As will be evident to a person of ordinary skill in the
art, the individual nonwoven sheets do not have to be square or
rectangular but can be any shape as defined by a desired pattern
formed by the impermeable material. Additionally, a single belt can
be designed to produce a plurality of individual nonwoven sheets
having varying shapes and sizes.
[0036] In order to ensure that the individual nonwoven sheets are
well separated from each other at the forming stage of the
manufacturing process, the impermeable material applied to the
fabric surface forms a plurality of protuberances (protrusions) on
the surface that can have various cross-sectional shapes. The
protuberances ensure that the fibers on each side of the
protuberances are well separated and are therefore prevented from
interacting or becoming entangled with one another. Examples of the
various cross-sectional shapes for the protuberances include, but
are not limited to: thin, low profile rectangular shapes 40 shown
in FIG. 3A; square shapes 42 having sides 43 of equal lengths as
shown in FIG. 3B; high profile rectangular shapes 45 as depicted in
FIG. 3C that have a height 50 equal to the thickness of the fiber
layers being deposited on the fabric; and shapes having a
cross-sectional profile designed to mechanically separate the
fibers of the nonwoven web, such as, but not limited the triangular
shape 55 in FIG. 3D; and a rectangular shape 60 having chamfered
corners 40 as depicted in FIG. 3E. Essentially, any shape or
material that produces individual nonwoven sheets on the fabric
surface can be used to form the protuberances.
[0037] It is important that the materials used to construct the
protuberances must be impermeable to air. The protuberances may be
constructed of a thermoplastic material similar to that disclosed
in commonly assigned, copending application, U.S. patent
application entitled "Fabric with V-Guides", Ser. No. 10/631,937
(U.S. 2005/0025935) albeit for a different purpose, the contents of
which are incorporated herein by reference, or they can be formed
from a polymeric resin material, such as, but not limited to,
polyamide, polyester, polyetherketone, polypropylene, polyolefin,
polyurethane, polyketone, or polyethylene terephthalate resins. The
protuberances may also be constructed using silicone, rubber or a
rubber like material. As previously discussed, the protuberances
may be in the form of a coating, an extrusion, a material
deposition or they can be pre-formed strips or pieces of
impermeable material that are mechanically attached to the fabric
or formed in a manner as discussed in aforesaid U.S. patent
application Ser. No. 10/334,211. In the case of a thermoplastic
material, the protuberances may be attached to the fabric by
melting of a portion of the protuberance in order to encapsulate a
portion of the fabric.
[0038] It is important to note that where the impermeable material
is applied to the web forming side of the fabric, the corresponding
portions on the backside or non-web forming side of the fabric,
must not have any surface irregularities due to the addition of the
impermeable material as compared to the remainder of the belt. This
is because the backside surface of the fabric is in contact with
the various rolls and vacuum boxes of the manufacturing apparatus.
Therefore, any surface irregularities will adversely affect the
fabric's travel through the apparatus and bleed vacuum, which
lowers the effectiveness of the airflow system.
[0039] Although a preferred embodiment of the present invention and
modifications thereof have been described in detail herein, it is
to be understood that this invention is not limited to this precise
embodiment and modifications, and that other modifications and
variations may be effected by one skilled in the art without
departing from the spirit and scope of the invention as defined by
the appended claims.
* * * * *