U.S. patent application number 11/500065 was filed with the patent office on 2007-05-10 for napped face stitch bonded fabric and related process.
Invention is credited to Robert Fontaine, Patrick Swanson, Martin Wildeman.
Application Number | 20070101771 11/500065 |
Document ID | / |
Family ID | 38002400 |
Filed Date | 2007-05-10 |
United States Patent
Application |
20070101771 |
Kind Code |
A1 |
Wildeman; Martin ; et
al. |
May 10, 2007 |
Napped face stitch bonded fabric and related process
Abstract
A pile fabric of stitch bonded construction. A ground yarn is
stitchbonded into a substrate to define a ground layer. A pile yarn
is stitchbonded into the substrate in combination with the ground
yarn. During formation at least a portion of the pile yarns are
shifted over sinker fingers between non-adjacent needles such that
loops extend in arching relation over at least one intermediate
needle line. Once the yarns have been stitchbonded into the
substrate, the upstanding loops are subjected to a napping
treatment wherein the loops are pulled away from the substrate
until broken. An arrangement of split and frayed yarn ends is
formed over the ground layer.
Inventors: |
Wildeman; Martin;
(Spartanburg, SC) ; Swanson; Patrick; (Pattaya,
TH) ; Fontaine; Robert; (Spartanburg, SC) |
Correspondence
Address: |
James M. Robertson
233 South Pine Street
Spartansburg
SC
29302
US
|
Family ID: |
38002400 |
Appl. No.: |
11/500065 |
Filed: |
August 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60708563 |
Aug 16, 2005 |
|
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Current U.S.
Class: |
66/169R |
Current CPC
Class: |
D04B 21/02 20130101;
D10B 2403/0111 20130101; D04B 21/165 20130101 |
Class at
Publication: |
066/169.00R |
International
Class: |
D04B 1/00 20060101
D04B001/00 |
Claims
1. A method of forming a stitchbonded pile fabric of multi-bar
construction, the method comprising the steps of: providing a
substrate layer of fibrous non-woven construction; stitching a
plurality of ground yarns through the substrate layer using an
arrangement of needles in the cross machine direction so as to
define an arrangement of substantially parallel stitch lines
running in the machine direction of the fabric so as to form a
ground covering across the substrate layer; stitching at least a
first pile forming yarn of multi-filament construction through the
substrate such that said first pile forming yarn defines a first
arrangement of loop elements projecting away from the ground
covering, wherein during formation of the first arrangement of loop
elements, the first pile forming yarn is shogged from a first
needle to a second non-adjacent needle in the cross machine
direction such that said first pile forming yarn travels over a
plurality of sinker fingers between the first and second needles
whereby at least a portion of the loop elements extend in raised
arched relation over at least one intermediate needle line; and
napping the fabric formed by the stitching steps such that at least
a portion of the loop elements extending in arched relation over
intermediate needle lines are pulled away from the substrate and
broken to define surface of frayed yarn ends across the fabric.
2. The invention as recited in claim 1, wherein the substrate layer
comprises needlepunched staple fibers with a heat activated bonding
constituent.
3. The invention as recited in claim 2, wherein the substrate layer
is characterized by a mass per unit area of about 20 to about 200
grams per square meter.
4. The invention as recited in claim 1, wherein said ground yarns
are stitched through the substrate layer in a substantially fully
threaded stitching arrangement.
5. The invention as recited in claim 4, wherein said ground yarns
are stitched through the substrate layer in a chain stitch
pattern.
6. The invention as recited in claim 1, wherein the ground yarns
comprise multi-filament flat yarns.
7. The invention as recited in claim 1, wherein the ground yarns
comprise multifilament polyester yarns characterized by a linear
density in the range of about 50 to about 200 denier.
8. The invention as recited in claim 1, wherein at least a second
pile forming yarn of multi-filament construction is stitched
through the substrate such that that said second pile forming yarn
defines a second arrangement of loop elements projecting away from
the ground covering, wherein during formation of the second
arrangement of loop elements, the second pile forming yarn is
shogged from a third needle to a fourth needle in the cross machine
direction such that said second pile forming yarn travels over a
plurality of sinker fingers between the third and fourth needles,
and wherein at least one of the third and fourth needles forms an
intermediate needle line between the first and second needles.
9. The invention as recited in claim 8, wherein the first and
second pile forming yarns comprise textured polyester yarns
10. The invention as recited in claim 9, wherein the first and
second pile forming yarns are characterized by a linear density in
the range of about 50 to about 1000 denier.
11. A pile fabric formed by the method of claim 1
12. A method of forming a stitchbonded pile fabric of multi-bar
construction, the method comprising the steps of: providing a
substrate layer of fibrous non-woven construction; stitching a
plurality of ground yarns through the substrate layer using an
arrangement of needles in the cross machine direction so as to
define an arrangement of substantially parallel stitch lines
running in the machine direction of the fabric so as to form a
ground covering across the substrate layer; stitching a plurality
of pile forming yarns of multi-filament construction through the
substrate such that at least a portion of said pile forming yarns
defines an arrangement of loop elements projecting away from the
ground covering, wherein during formation of the arrangement of
loop elements, a portion of the pile forming yarns are shogged back
and forth between non-adjacent needles in the cross machine
direction such that the pile forming yarns travel over a plurality
of sinker fingers between the non-adjacent needles whereby at least
a portion of the loop elements extend in raised arched relation
over at least one intermediate needle line; and napping the fabric
formed by the stitching steps such that at least a portion of the
loop elements extending in arched relation over intermediate needle
lines are pulled away from the substrate and broken to define a
surface of frayed yarn ends across the fabric.
13. The invention as recited in claim 12, wherein the pile forming
yarns are stitched concurrently with formation of the ground
covering using common needles.
14. The invention as recited in claim 12, wherein the substrate
layer comprises needlepunched staple fibers with a heat activated
bonding constituent.
15. The invention as recited in claim 12, wherein said ground yarns
are stitched through the substrate layer in a substantially fully
threaded stitching arrangement.
16. The invention as recited in claim 15, wherein said ground yarns
are stitched through the substrate layer in a chain stitch
pattern.
17. The invention as recited in claim 12, wherein the pile forming
yarns comprise textured polyester yarns
18. The invention as recited in claim 17, wherein the pile forming
yarns are characterized by a linear density in the range of about
50 to about 1000 denier.
19. A pile fabric formed by the method of claim 12.
20. The invention as recited in claim 12, wherein during the
napping step substantially all of the loop elements extending in
arched relation over intermediate needle lines are pulled away from
the substrate and broken.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority from
U.S. Provisional Application 60/708,563 having a filing date of 16
Aug. 2005, the contents of which are incorporated herein by
reference in their entirety.
TECHNICAL FIELD
[0002] The present invention generally pertains to plush face
fabrics suited for use in home furnishing such as for use in
constructing upholstery. More particularly, the present invention
is directed to a napped face stitchbonded fabric and to a process
for making such fabric.
BACKGROUND
[0003] Felt-like and suede-like fabrics are well known for use in
applications such as furnishing and automotive seating upholstery.
These fabrics have a pleasing look and tactile feel to their front
side. Moreover, these fabrics can stand up to high friction
environments while keeping their appearance intact. In the past,
processes for creating these fabrics have included shearing,
napping, or brushing warp-knitted or woven loop piled fabrics.
While such products provide suitable performance characteristics,
they face deficiencies due to the costs associated with forming the
initial knit and woven fabric substrates.
[0004] In order to address the deficiencies of using woven or knit
base fabrics while still providing a desired plush pile surface, it
has been proposed to use stitch bonded base fabrics formed with
rows of parallel stitch lines subjected to a sanding or shearing
process. Such a product is disclosed in my U.S. Pat. No. 6,423,393
the teachings of which are incorporated herein by reference as if
fully set forth herein. Due to the application of the sanding or
shearing process, such products exhibit a relatively dense plush
pile face with the individual yarns being sharply clipped or
cut.
[0005] Napping is a fabric treatment process wherein a face of the
fabric is moved across a treatment apparatus such as one or more
rotating cylinders incorporating an arrangement of extensions such
as metal points or burrs such that the extensions pluck yarns away
from the surface and form a downy layer of broken fibers across the
surface. In the past, napping has been used on woven and knitted
fabrics to form goods such as flannel, wool broadcloth and the
like. However, as indicated in my prior patent 6,423,393, napping
has been considered too harsh for stitchbonded fabrics.
[0006] As will be recognized, stitchbonded fabrics are well known.
Such fabrics typically utilize a relatively light-weight substrate
layer such as a non-woven web or the like through which parallel
rows of stitching yarns are passed by needles to form an
arrangement of stitches. The stitching yarns form the body of the
fabric and define the fabric surface structure. The stitching yarns
themselves provide coherency and strength to the fabric. In
formation of a stitch bonded fabric yarns may be passed between
adjacent rows over sinker fingers to provide a looped pile surface.
The rows of stitches are typically formed in relatively close
relation to one another so as to provide desired coverage levels
and to impart desired strength characteristics. Due to the close
proximity of the stitch rows, napping has generally been considered
an unsuitable surface treatment since the crossing yarns between
the rows tend to be of inadequate length to efficiently engage the
burrs on the napping machine. Moreover, the bristles of the nappers
and/or the brushes tend to dig into the stitchbonded fabrics,
causing the staple fibers of the nonwoven web to be pulled up
through the outer stitching.
SUMMARY OF THE INVENTION
[0007] The present invention provides advantages and alternatives
over the prior art by providing a process whereby fabrics of
stitchbonded construction may be effectively treated by napping. A
resultant fabric construction is also provided.
[0008] According to one aspect of the invention the stitch bonded
fabric includes a planar substrate such as a nonwoven web of staple
fibers. A ground yarn is stitchbonded into the substrate in a
substantially flat stitch arrangement such as a fully threaded
chain stitch, tricot stitch or the like to form rows of stitches
defining a ground covering across the substrate. A pile yarn is
also stitchbonded into the substrate to form loop pile stitches
with upstanding loops. During formation, at least a portion of the
pile yarns are shifted over multiple sinker fingers between
non-adjacent needles such that loops extend in arching relation
over at least one intermediate needle line. Once the yarns have
been stitchbonded into the substrate, the upstanding loops are
subjected to a napping treatment wherein the loops are pulled away
from the substrate until broken. An arrangement of split and frayed
yarn ends is thus formed over the ground layer.
[0009] Other features and aspects of the present invention are
discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth more particularly in the remainder of the
specification, which makes reference to the appended figures in
which:
[0011] FIG. 1 illustrates schematically a two bar stitch bonding
process for selectively forming an arrangement of surface loops in
combination with a cooperating ground yarn system through a fibrous
substrate;
[0012] FIG. 2 illustrates schematically the stitching of a ground
yarn in an arrangement of substantially flat chain stitches by a
multiplicity of reciprocating needles in a fully threaded
arrangement;
[0013] FIG. 3 illustrates schematically the stitching of a surface
yarn in a pattern of extended length loops formed by shifting
loop-forming yarns between non-adjacent needles;
[0014] FIG. 4 illustrates a representative napping process for
tensioned breakage of surface loops; and
[0015] FIG. 5 illustrates a stitchbonded fabric having a napped
face of frayed surface yarns.
[0016] While the invention has been illustrated and will
hereinafter be described in connection with certain exemplary
embodiments and practices, it is to be understood that in no event
is the invention to be limited to such illustrated and described
embodiments and practices. On the contrary, it is intended that the
present invention shall extend to all alternatives and
modifications as may embrace the general principles of this
invention within the full and true spirit and scope thereof.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] Reference will now be made to the drawings wherein, to the
extent possible, like reference numerals designate like components
throughout the various views. In general, the fabric of the present
invention comprises a multi-bar stitchbonded fabric made from a
multiplicity of yarns stitched through a substrate, particularly a
nonwoven substrate. As it is known in the art, a multi-bar fabric
refers to a stitchbonded fabric made using at least two independent
guide bars.
[0018] Exemplary fabric construction practices are illustrated and
will be described through reference to a stitch bonding machine
such as a Liba stitch bonding machine although it is likewise
contemplated that other stitch bonding equipment may likewise be
used if desired. Referring simultaneously to FIGS. 1-3, according
to one contemplated practice, a substrate material 30 such as a
carded and cross-lapped fleece or a needle punched or spun bonded
fleece is conveyed to a stitch-forming position in the direction
indicated by the arrow. If desired, the substrate material 30 may
include a percentage of low melting point fibers such as low
melting point polyester or bicomponent polyester having a core of
relatively high melting point material and a sheath of lower
melting point polyester to facilitate heat activated point bonding
so as to enhance structural integrity.
[0019] As illustrated, the stitch forming position is defined by a
row of reciprocating needles 34 extending in adjacent relation to
one another across the width of the substrate material 30 in the
cross machine direction substantially transverse to the direction
of movement of the substrate material 30. As will be appreciated,
while only four needles have been illustrated, in actual practice a
large number of such needles are arranged in close relation to one
another between the fingers 47 of a sinker bar. By way of example
only, and not limitation, it is contemplated that the so called
gauge or needle density in the cross machine direction is
preferably about 28 needles per inch, although higher or lower
needle densities may likewise be utilized if desired.
[0020] According to the illustrated and potentially preferred
practice, at least two yarns systems are used to form stitches
through the substrate material 30. In the potentially preferred
practice, a ground yarn 36 (FIG. 2) is carried through a first set
of moveable yarn guides 38 carried by a first guide bar (not shown)
for cooperative substantially fully threaded engagement with the
needles 34 across the width of the substrate material 30. For ease
of reference, the substrate material 30 is not illustrated in FIG.
2.
[0021] As will be appreciated by those of skill in the art, in
operation the ground yarn 36 is moved into engagement with the
needles which, in turn, carry the ground yarn 36 in a reciprocating
manner through the substrate material 30 without engaging fingers
47 of the sinker bar. This results in formation of an arrangement
of substantially flat cooperating ground yarn stitches 40 extending
in relatively closely spaced rows along the substrate material 30.
By way of example only, and not limitation, the cooperating ground
yarn stitches 40 may be held in a full chain stitch configuration
although other stitch arrangements including tricot stitches and
the like may likewise be utilized if desired. Preferably, the
spacing of the stitch lines formed by the ground yarn 36 will be
close enough that the ground yarn stitches 40 define a
substantially continuous covering across the technical back 41 of
the substrate material 30. The ground yarn 36 and the substrate
material 30 thus define a substantially stable stitch bonded
structure.
[0022] As illustrated in FIGS. 1 and 3, in accordance with a
potentially preferred practice, an arrangement of loop elements 42
is formed projecting away from, and standing above, the ground yarn
stitches 40 in a predefined pattern across the technical back 41 of
the fabric. According to the preferred practice of the present
invention, the loop elements 42 are formed substantially
concurrently with the formation of the ground yarn stitches 40
through the substrate material 30. As best illustrated in FIG. 3
(wherein the substrate is not shown for ease of reference)
according to one potentially preferred practice, loop elements 42
may be formed by a pile yarn 44 threaded through moveable yarn
guides 46 carried by a guide bar (not shown). While only two pile
yarns 44 are illustrated for explanatory purposes, it is to be
understood that in actual practice, multiple pile yarns 44 are used
across the width of the fabric threaded in a pattern relative to
the needles to impart a desired loop arrangement.
[0023] As illustrated, the pile yarn 44 is preferably carried in
alternating fashion back and forth between a first pair of
non-adjacent needles thereby forming an arrangement of loop
elements 42 that extend in arching relation over one or more
intermediate needle rows corresponding to skipped needles between
the cooperating pair of non-adjacent needles. In this procedure,
the pile yarn passes over two or more sinker fingers 47 thus
maintaining the desired raised arched relation. Arranging the loop
elements to span across one or more intermediate needle rows gives
rise to extended length loops that facilitates grasping by napping
burrs in a subsequent napping operation as will be described more
fully hereinafter. As shown, it is contemplated that the
intermediate needles may also be engaged by pile forming yarns from
other yarn guides so as to form loops as part of at least a second
cooperating needle pair. Of course, the intermediate needles can
also be left free of pile forming yarns if desired. Thus, the
concentration of loop elements can be readily controlled. In this
regard, by controlling yarn guide movement, arched loop elements
may extend away from every needle row to predetermined non-adjacent
needle rows if desired.
[0024] As previously indicated, the substrate used as the base of
the stitchbonded fabric is preferably a nonwoven web structure,
although a film, a woven, or a knitted product may also be used if
desired. A nonwoven fiber fleece formed from staple fibers of a
synthetic material such as polyester may be particularly preferred.
However, other synthetic fibers such as polypropylene or nylon as
well as natural fibers such as wool may be used if desired. A blend
of different fibers may also be used. According to one contemplated
practice the staple fibers can have a denier of from about 2 to
about 6 with a staple length of about 2 to 4 inches. In one
potentially preferred embodiment, the staple fibers have a denier
of about 4 and a staple length of about 4 inches.
[0025] If desired, binder fibers can be incorporated into the
nonwoven substrate in combination with the staple fibers. As used
herein, binder fibers refers to fibers that when subjected to heat
will bond with one another and with other materials contained
within the web. Binder fibers are typically made from synthetic
materials having a relatively low softening temperature such as low
melting point polyesters. Although the binder fibers can be made
entirely form a low melting point polymer, in one particular
embodiment of the present invention, the binder fibers incorporated
into the nonwoven substrate are multicomponent fibers, such as
bicomponent fibers in which the low melting point polymer comprises
the sheath polymer and a higher melting point fiber comprises the
core polymer.
[0026] The fiber fleece is preferably formed by carding and
cross-lapping a nonwoven web followed by needle punching to impart
fiber cohesion. However, other construction techniques such as air
laying, spun bonding and the like may also be used if desired. The
basis weight of the nonwoven substrate can vary depending upon the
particular application for which the fabric is being used. However,
for most applications such as upholstery and the like, the nonwoven
substrate can have a basis weight of from about 80 to about 150
grams per square meter or higher.
[0027] The pile yarn 44 is preferably a multifilament yarn of
polyester, nylon or other suitable synthetic fiber. By way of
example only, and not limitation, one contemplated construction for
the pile yarn is 150 denier, 200 filament polyester. One
potentially preferred stitch notation for insertion of the pile
yarn is 1,0/2, 3. The pile stitch density is preferably in the
range of about 20 to about 30 stitches per inch and more preferably
about 23 to about 26 stitches per inch. Although the pile yarn is
preferably a texturized filament yarn, it is also contemplated that
flat yarns and even some spun yarns may be used if desired.
[0028] According to a potentially preferred practice, the ground
yarns 36 are preferably flat, dull yarns meaning the yarns are not
texturized and refract little light. Although flat, dull yarns are
desirable, it should be understood that any suitable yarn may be
used without limitation. For instance, texturized and spun yarns
may be used if desired. As previously indicated, the ground yarns
36 are preferably stitched in covering relation to the substrate
material 30. Preferably, a chain stitch, such as 0.1/0.1, is used
which gives stability in the warp direction (machine direction).
Once incorporated into the substrate material, the ground yarn
provides the web with integrity and strength. According to one
contemplated practice, the ground yarn 36 is a multifilament
polyester yarn having a denier of from about 70 to about 150. One
exemplary ground yarn is a 70 denier 34 filament polyester.
Although ground yarns polyester may be preferred, it is likewise
contemplated that other synthetic and natural fibers may be
utilized if desired.
[0029] According to the potentially preferred practice, once the
substrate has been stitchbonded, the resultant fabric structure 43
is heat set by traditional techniques to impart stability. By way
of example, the fabric structure 43 may be conveyed through a
tenter frame such as will be well known to those of skill in the
art at about 350.degree. F. for about 30 seconds. During the heat
treatment the fabric is firmed up and the fibers are stabilized.
Also, the texturized yarns may bulk thereby making the yarns look
fuller. Further, during heat treatment, any binder fibers that may
be present in the substrate melt and bond. After heat setting, the
fabric can be dyed as desired as is known within the textile art.
Of course, it is also contemplated that the fabric can be dyed
after napping if desired.
[0030] In accordance with the contemplated practice, after heat
treatment and any desired dyeing, the stitch bonded fabric is
preferably delivered to a napping operation where the surface loops
42 formed by the pile yarns 36 are preferably broken by applied
tension as they are pulled away from the substrate material 30.
According to one potentially preferred practice, the fabric 43 is
delivered to a napping machine 60 such as a double action napper as
will be well known to those of skill in the art. As will be
appreciated, in the napping machine 60 the technical back 41 of the
fabric with the formed surface loops 42 contacts an arrangement of
burr wheels 64. In the potentially preferred practice, the burr
wheels are mounted on a cylinder that rotates in the same direction
as the fabric but at a different speed so as to cause the burr
wheels to pluck and brush the surface loops 42.
[0031] A representative embodiment of a napped fabric 70 formed by
the practice of the present invention is illustrated in FIG. 5. As
shown, the napped fabric 70 includes a pile layer 72 disposed above
a backing formed by the substrate material 30 and ground yarn
stitches 40. Due to the tensioned breakage caused by the napping
treatment, at least a substantial portion of the pile yarns are
frayed such that free ends of individual broken filaments and/or
fibrils of the pile yarns define a surface covering across a user
contact surface of the napped fabric 70.
[0032] The present invention has been described with reference to
exemplary and potentially preferred embodiments and practices.
However, it will be apparent to those skilled in the art that many
changes can be made in the embodiments described without departing
from the scope of the present invention. Thus, in no event is the
scope of the present invention to be limited to the structures and
practices described in this application. Rather, it is intended
that the invention shall extend to all alternatives and equivalents
embracing the broad principles of this invention within the full
spirit and scope thereof.
* * * * *