U.S. patent application number 10/291206 was filed with the patent office on 2003-07-03 for woven fabrics particularly useful in the manufacture of occupant support structures.
Invention is credited to Gillig, Dan P., Salway, Doug, Waldrop, Anthony R., Williams, Jan L..
Application Number | 20030124933 10/291206 |
Document ID | / |
Family ID | 23785494 |
Filed Date | 2003-07-03 |
United States Patent
Application |
20030124933 |
Kind Code |
A1 |
Salway, Doug ; et
al. |
July 3, 2003 |
Woven fabrics particularly useful in the manufacture of occupant
support structures
Abstract
A fabric particularly useful in the manufacture of occupant
support structures is described. The fabric is desirably leno woven
to have a high degree of openness and such that at least a
plurality of the yarn intersections are stabilized from relative
motion. The fabric includes elastomeric synthetic yarns in at least
one fabric direction. At least some of the points of yarn
intersection can be supplementally stabilized from relative motion,
such as through the use of bicomponent yarns having a sheath which
is melted to secure intersecting yarns together. The fabric is also
resistant to ultraviolet irradiation so that it retains its
physical properties after accelerated exposure to UV irradiation.
The fabric provides good support and ventilation, and is suitable
for use as a surface fabric in automotive and seating
applications.
Inventors: |
Salway, Doug; (Greenwood,
SC) ; Williams, Jan L.; (Greenville, SC) ;
Waldrop, Anthony R.; (Easley, SC) ; Gillig, Dan
P.; (Greer, SC) |
Correspondence
Address: |
Jeffery E. Bacon
Milliken & Company
Legal Department, M-495
PO Box 1926
Spartanburg
SC
29304
US
|
Family ID: |
23785494 |
Appl. No.: |
10/291206 |
Filed: |
November 8, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10291206 |
Nov 8, 2002 |
|
|
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09449789 |
Nov 26, 1999 |
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Current U.S.
Class: |
442/184 ;
442/182; 442/200; 442/208; 442/209; 442/301 |
Current CPC
Class: |
Y10T 442/3024 20150401;
Y10T 442/3146 20150401; D03D 9/00 20130101; Y10T 442/3154 20150401;
Y10T 442/326 20150401; Y10T 442/3228 20150401; Y10T 442/3008
20150401; Y10T 442/322 20150401; Y10T 442/3976 20150401; D03D 19/00
20130101; Y10T 442/3285 20150401; Y10T 442/3179 20150401 |
Class at
Publication: |
442/184 ;
442/182; 442/200; 442/208; 442/209; 442/301 |
International
Class: |
D03D 015/08; D03D
017/00; D03D 015/00 |
Claims
We claim:
1. A textile fabric comprising: a woven fabric having a warp yarn
set and a weft yarn set, and in which at least a plurality of the
yarns forming the warp yarn set are woven in a leno configuration
such that said warp yarns are secured about yarns of the weft yarn
set, said fabric comprising at least about 15% open area and
exhibiting at least about 0.5 pounds strength in each of the warp
and weft directions when subjected to a yarn unravel test.
2. A textile fabric according to claim 1, wherein said fabric
exhibits at least about 2 pounds strength in the warp direction and
at least about 1 pound strength in the weft direction when
subjected to a yarn unravel test.
3. A textile fabric according to claim 1, wherein said fabric
comprises at least about 35% open area.
4. A textile fabric according to claim 1, wherein said fabric
comprises at least about 45% open area.
5. A textile fabric according to claim 1, wherein at least one of
said warp and weft yarn sets comprises elastomeric synthetic
yarns.
6. A textile fabric according to claim 5, wherein said elastomeric
synthetic yarns are resistant to UV irradiation such that said
fabric retains at least about 50% of its initial breaking strength
when measured in the elastomeric synthetic yarn direction following
accelerated exposure to 225 kilojoules of UV irradiation.
7. A textile fabric according to Clam 6, wherein said elastomeric
yarns are resistant to UV irradiation such that said fabric retains
at least about 70% of its initial breaking strength when measured
in the elastomeric synthetic yarn direction following accelerated
exposure to 225 kilojoules of UV irradiation.
8. A textile fabric according to claim 5, wherein said elastomeric
synthetic yarns are characterized by an elongation at break of at
least about 90% and retain at least about 80% of their tensile
strength following accelerated exposure to 488 kilojoules of UV
irradiation.
9. A textile fabric according to claim 5, wherein said elastomeric
synthetic yarns comprise at least about 40% by weight of the
fabric.
10. A textile fabric according to claim 1, wherein at least some of
the intersections of the yarns of the warp and weft yarn sets are
bonded together.
11. A textile fabric according to claim 10, wherein at least one of
said warp and weft yarn sets comprises bicomponent sheath/core
elastomeric yarns and said sheath component is melted to bond
intersections of the yarns of said warp and weft yarn sets.
12. A textile fabric comprising: a first yarn set interwoven with a
second yarn set in a leno configuration, wherein at least one of
said first and second yarn sets comprises elastomeric synthetic
yarns and said elastomeric synthetic yarns are bonded to yarns of
the other of said yarn sets to provide a fabric having high
dimensional stability.
13. A textile fabric according to claim 12, wherein said first and
second yarn sets are woven together to form an open fabric having
at least about 15% open space.
14. A textile fabric according to claim 12, wherein said first and
second yarn sets are woven together to form an open fabric having
at least about 35% open space.
15. A textile fabric according to claim 12, wherein said first and
second yarn sets are woven together to form an open fabric having
at least about 45% open space.
16. A textile fabric according to claim 12, wherein said
elastomeric synthetic yarns comprise at least about 40% by weight
of the fabric.
17. A textile fabric according to claim 12, wherein said
elastomeric synthetic yarns comprise a sheath/core bicomponent
filament, and said elastomeric synthetic yarns are bonded to yarns
of the other of said yarn sets by melt bonding of the bicomponent
filament.
18. A textile fabric according to claim 12, wherein said fabric
retains at least about 50% of its initial breaking strength when
measured in the elastomeric synthetic yarn direction following
accelerated exposure to 225 kilojoules of UV irradiation.
19. A textile fabric according to claim 18, wherein said fabric
retains at least about 70% of its initial breaking strength when
measured in the elastomeric synthetic yarn direction following
accelerated exposure to 225 kilojoules of UV irradiation.
20. A textile fabric according to claim 18, wherein said fabric
retains at least about 50% of its initial breaking strength when
measured perpendicular to the elastomeric synthetic yarn direction
following accelerated exposure to 225 kilojoules of UV
irradiation.
21. A textile fabric according to claim 19, wherein said fabric
retains at least about 50% of its initial breaking strength when
measured perpendicular to the elastomeric synthetic yarn direction
following accelerated exposure to 225 kilojoules of UV
irradiation.
22. A textile fabric according to claim 12, wherein said fabric
exhibits at least about 0.5 pounds strength in each of the first
and second directions when subjected to a yarn unravel test.
23. A textile fabric according to claim 22, wherein said fabric
exhibits at least about 2 pounds strength in the first direction
and at least about 1 pound strength in the second direction when
subjected to a yarn unravel test.
24. A textile fabric according to claim 12, wherein said first
direction comprises the warp direction and the second direction
comprises the fill direction of the fabric.
25. A textile fabric comprising a first plurality of elastomeric
synthetic yarns extending in a first direction interwoven with a
second plurality of yarns extending in a second direction generally
transverse to said first direction, wherein said elastomeric
synthetic yarns running in the first direction comprise at least
about 40% by weight of the fabric and said elastomeric synthetic
yarns are characterized by an elongation at break of at least about
90% and retain at least about 80% of their tensile strength
following accelerated exposure to 488 kilojoules of UV irradiation,
and wherein said first and second plurality of yarns are interwoven
in a leno configuration.
26. A textile fabric according to claim 25, wherein said first and
second pluralities of yarns are woven together to form an open
fabric having at least about 15% open space.
27. A textile fabric according to claim 25, wherein said first and
second pluralities of yarns are woven together to form an open
fabric having at least about 35% open space.
28. A textile fabric according to claim 25, wherein said first and
second pluralities of yarns are woven together to form an open
fabric having at least about 45% open space.
29. A textile fabric according to claim 25, wherein said first and
second plurality of yarns are woven to define a plurality of yarn
intersections, and at least some of said yarn intersections are
bonded together.
30. A textile fabric according to claim 25, wherein said
elastomeric synthetic yarns are bicomponent sheath/core elastomeric
yarns having a sheath component which has a melt temperature that
is at least about 30.degree. F. below the melting point of the core
component.
31. A textile fabric according to claim 30, wherein portions of the
bicomponent sheath/core elastomeric yarns are meltbonded to the
second plurality of yarns to form a plurality of bonded yarn
intersections.
32. A textile fabric according to claim 25, wherein said fabric
retains at least about 50% of its initial breaking strength when
measured in the elastomeric synthetic yarn direction following
accelerated exposure to 225 kilojoules of UV irradiation.
33. A textile fabric according to claim 32, wherein said fabric
retains at least about 70% of its initial breaking strength when
measured in the elastomeric synthetic yarn direction following
accelerated exposure to 225 kilojoules of UV irradiation.
34. A textile fabric according to claim 32, wherein said fabric
retains at least about 50% of its initial breaking strength when
measured perpendicular to the elastomeric synthetic yarn direction
following accelerated exposure to 225 kilojoules of UV
irradiation.
35. A textile fabric according to claim 25, wherein said fabric
exhibits at least about 0.5 pounds strength in each of the first
and second directions when subjected to a yarn unravel test.
36. A textile fabric according to claim 35, wherein said fabric
exhibits at least about 2 pounds strength in the first direction
and at least about 1 pound strength in the second direction when
subjected to a yarn unravel test.
37. A textile fabric according to claim 25, wherein said first
direction comprises the warp direction and the second direction
comprises the fill direction of the fabric.
Description
FIELD OF THE INVENTION
[0001] The invention generally relates to woven fabric
constructions. More specifically, the invention relates to woven
fabrics having good durability, strength, dimensional stability and
ventilation properties which are particularly adapted for use in
the production of occupant support structures such as seating,
bedding and the like.
BACKGROUND OF THE INVENTION
[0002] Traditional occupant support structures such as seating,
bedding, and the like are generally constructed from a fabric
support secured to some form of frame. Often occupant support
structures include additional support elements such as springs,
cushions, pads, straps, webs or the like. Such additional support
elements typically constitute a large part of the overall weight
and dimension of the occupant support structures.
[0003] In many end uses it is desirable to minimize the weight of
the overall structure. For example, in the manufacture of transport
vehicles such as cars and airplanes, the weight of the overall
structure can influence variables such as fuel efficiency, freight
charges, and the like. Likewise, many occupant support structures
for home and office use (e.g. chairs, sofas and the like) are often
moved about frequently. In such situations, it would be preferable
to minimize the weight of the structure to facilitate its movement.
Therefore, it can be desirable in many cases to minimize the weight
of the occupant support structures. However, it is also important
that they retain the ability to provide proper support and comfort
of their particular end use.
[0004] Another disadvantage associated with many conventional forms
of occupant support structures is that a number of the materials
typically used to produce these structures tend to feel cold or hot
to a user depending on the particular environmental conditions. For
example, the tendency for an automobile seat to feel hot can be
readily appreciated by anyone who has sat on a leather car seat in
the summer heat. In addition, the materials are generally not
breathable, and therefore they tend to block the flow of air past
adjacent portions of a user's body. As a result, the back of the
legs of a seated individual can become sweaty and uncomfortable
following long periods of sitting on a seat formed of conventional
material.
[0005] Furthermore, the difficulty and costs associated with
assembly of occupant support structures generally are related to
the number of structural elements required for their production. To
reduce the complexity of the assembly process, it may therefore in
many cases be desirable to manufacture occupant support structures
using a minimal number of elements. However, the reduction in the
number of elements must be balanced against the need to achieve
particular performance capabilities.
[0006] In many end uses, the materials used to produce the occupant
support structures are exposed to a variety of degradory forces.
For example, seats in automobiles are exposed to a wide range of
temperatures, compressive forces, lateral shearing forces and the
like. In addition, such support structures are commonly exposed to
ultra-violet (UV) irradiation on an extended basis from the
sunlight which passes through the windshield and the windows. The
UV irradiation tends to undesirably degrade many kinds of
materials, rendering them unsuitable for use as surface fabrics in
environments where they can be exposed to a high degree of UV
irradiation. Therefore, with the minimization of elements, the
strength and durability of the elements that are utilized becomes
increasingly important. Furthermore, manufacturers must typically
take other properties such as tactile properties, hand, drape and
the like into consideration to ensure a proper balance of
properties is achieved for the particular end use for which the
fabric is being manufactured.
[0007] Materials which have been proposed for use in the
manufacture of occupant support structures are described in
commonly-assigned U.S. Pat. Nos. 5,533,789 and 5,596,888, each to
McLarty, III et al., the disclosures of which are incorporated
herein by reference. The McLarty '789 patent describes a seating
structure having portions made from a weft inserted warp knit
fabric. The fabric has an elastomeric monofilament yarn in the warp
forming a performance side, an elastomeric wrapped filament yarn in
the weft forming an aesthetic surface, and a knit filament yarn
tying the warp and the weft together.
[0008] The McLarty '888 patent describes a knit furniture support
fabric having multi-directional stretch characteristics and
possessing sufficient strength and durability to function as a
support in a seating or bed structure. The furniture support fabric
is a four bar knit structure including two yarns of textured
polyester and two yarns of elastomeric monofilament knit together
such that the fabric has an elongation at break of at least 17
percent in both the warp and fill directions. While providing good
physical properties for many end use applications, it has been
found that fabrics made according to the McLarty '789 and '888
patents have a harsher hand than is desired for some particular end
use applications.
[0009] U.S. Pat. No. 4,469,739 to Gretzinger et al. describes woven
furniture support materials made in part from elastomer
monofilaments and in part from a non-elastomeric yarn. The
non-elastomeric yarn is described as being provided in the warp
direction of the fabric in the preferred embodiment of the
structure. The patent describes that the yarns can be melted at
their intersections with each other, or alternatively can be
affixed to each other at the intersections by selecting the weaving
pattern to be of such a configuration that the yarn will lock in
place about the filament, thereby obviating the need for adhesive
or melting of the elastomer.
[0010] As noted above, many fabrics used as components in occupant
support structures are exposed to ultraviolet irradiation for
extended periods of time. For example, automotive seating
materials, outdoor chairs and the like experience extended exposure
to UV irradiation. In many cases, the UV irradiation exposure
degrades the fibers forming the fabrics, thereby undesirably
limiting the useful life of the structure or rendering certain
fabrics unsuitable for particular end uses.
[0011] An example of a fabric capable of resisting degradation due
to exposure to UV irradiation is described in commonly-assigned
U.S. Pat. No. 5,856,249 to Waldrop et al., the disclosure of which
is incorporated herein by reference. The Waldrop patent describes a
fabric having a plurality of elastomeric synthetic yarns running in
a first direction interwoven with a plurality of synthetic yarns
running in a second direction substantially transverse to the first
direction, where the elastomeric synthetic yarns running in the
first direction comprise not less than about 40 percent by weight
of the textile fabric. The elastomeric yarns running in the first
direction are further characterized by the fact they have an
elongation at break of not less than about 50 percent, and they
retain not less than about 80 percent of their tensile strength
upon accelerated exposure to 488 kilojoules of ultraviolet
irradiation. The patent describes that the fabric is preferably a
woven fabric, and particularly, one which is woven in a barathea
weave construction. Because of its resistance to degradation from
exposure to UV irradiation, the fabric can be used as a surface
material in automotive seating applications.
[0012] In addition, commonly-assigned co-pending patent application
Ser. No. 09/224,980 to Waldrop et al., filed Jan. 4, 1999,
describes a fabric useful as an automotive upholstery surface
fabric. The disclosure of the '980 application is incorporated
herein by reference. The fabric has a plurality of elastomeric
synthetic yarns running in a first direction and a plurality of
synthetic yarns running in a second direction substantially
transverse to the first direction, with the elastomeric synthetic
yarns running in the first direction comprising not less than about
40 percent by weight of the upholstery fabric. The elastomeric
synthetic yarns running in the first direction have an elongation
at break of not less than about 70 percent and are UV
stabilized.
SUMMARY
[0013] The instant invention overcomes disadvantages associated
with conventional structures through the provision of a fabric
having desirable levels of durability, strength, dimensional
stability, and elastomeric properties, rendering it particularly
well-suited for use in the manufacture of occupant support
structures. The fabric of the invention has a good hand and retains
desirable physical properties, even after extended periods of
exposure to ultraviolet irradiation. As a result, it performs well
as a surface fabric in occupant support structures such as
automobile seats and the like. Furthermore, the fabric of the
instant invention has a large degree of openness, so as to provide
good ventilation characteristics. Because of its unique
construction, the fabric can be secured to a frame alone (i.e.,
without other fabric layers) to form a support structure or it can
be used in combination with other layers as desired. Furthermore,
the fabric can be cut into pieces of desired shape and size, and
fabricated into an end use product without undesirable levels of
fabric degradation through raveling or the like.
[0014] The fabrics of the invention achieve the desired properties
by utilizing elastomeric synthetic yarns in an open weave structure
formed by first and second sets of intersecting yarns. The fabric
is preferably woven in a leno weave or a variation thereof so that
warp yarns of the fabric are locked around at least some of the
fill, yarns. Yarns of the first and second yarn sets are also
desirably supplementally secured together at their
intersections.
[0015] In a preferred form of the invention, the elastomeric
synthetic yarns are preferably provided in the warp, and desirably
are of the bicomponent sheath/core variety. The sheath component
desirably has a melting temperature which is below that of the core
component, so that the sheath can be melted subsequent to weaving
to lock the yarns of the respective yarn sets together at their
intersections. The other yarn set may or may not include
elastomeric synthetic yarns, with the yarn used desirably being
selected to provide the fabric with a particular combination of
physical characteristics, such as a good hand and aesthetic
appearance.
[0016] At least some of the yarns forming the fabric are desirably
UV-resistant so that the fabric retains at least about 50%, and
more preferably at least about 70% of its initial breaking strength
when measured in the elastomeric synthetic yarn direction and at
least about 50% of its initial breaking strength when measured
perpendicular to the elastomeric synthetic yarn direction following
accelerated exposure to 225 kilojoules of UV irradiation.
[0017] The fabric has high strength and dimensional stability, and
resists unraveling. In addition, the fabric is also desirably open,
so that at least about 15% of a given area of the fabric is open
area, and more preferably at least about 30%. Even more preferred
is that the fabric constitutes at least about 35%, and more
preferably at least about 40% open area. In fact, it has been found
that fabrics having at least about 45% open area can be made
according to the instant invention, while retaining sufficient
strength and dimensional stability to enable them to be used in the
formation of occupant support structures. In addition, products
made according to the invention using yarns which are resistant to
UV irradiation are particularly useful in the formation of occupant
support structures which are exposed to UV irradiation on an
extended basis, such as automotive seating.
DETAILED DESCRIPTION
[0018] In the following detailed description of the invention,
specific preferred embodiments of the invention are described to
enable a full and complete understanding of the invention. It will
be recognized that it is not intended to limit the invention to the
particular preferred embodiments described, and although specific
terms are employed in describing the invention, such terms are used
in a descriptive sense for the purpose of illustration and not for
the purpose of limitation.
[0019] The fabric of the instant invention is constructed to
provide a high degree of fabric openness. Preferably, at least
about 15% of the surface area of a piece of fabric constitutes open
space (i.e. space between the fibers or yarns forming the fabric),
and more preferably at least about 30%. Even more preferably, at
least about 35% of the fabric is open space, and more preferably
about 40%. In some embodiments of the invention, it will be desired
to have at least about 45% of the area of the fabric constitute
open area.
[0020] The fabric according to the invention desirably includes a
first set of yarns extending in a first direction and a second set
of yarns extending in a second direction which is generally
transverse to the first direction. For example, the fabric is
desirably a woven fabric in which one of the first and second yarn
sets is a warp yarn set and the other of the first and second yarn
sets is a weft (i.e. filling) yarn set.
[0021] The fabric is woven to include a plurality of elastomeric
synthetic yarns in at least one of the first and second yarn sets,
preferably in the warp yarn set. In some embodiments of the
invention, elastomeric synthetic yarns are included in both the
first and second yarn sets. In a preferred form of the invention,
the elastomeric synthetic yarns are preferably monofilament yarns
having an elongation at break of at least about 50%, and preferably
a tensile strength of at least about 8 pounds force prior to
weaving, and more preferably at least about 8.5 pounds force. Even
more preferably, the elastomeric synthetic yarns are monofilament
yarns having an elongation at break of at least about 75%, and more
preferably at least about 90%, and even more preferably at least
about 100%.
[0022] In a particularly preferred form of the invention, the
elastomeric synthetic yarns are of the sheath/core variety in which
the sheath has a lower melting temperature than that of the core
component. In this form of the invention, the melting temperature
of the sheath is desirably at least about 30.degree. F. lower than
that of the core, for reasons which will be discussed more fully
hereinafter. Elastomeric synthetic yarns which have been found to
perform particularly well in the invention are distributed under
the tradename ELAS-TER.RTM. by Johns Manville of Spartanburg, S.C.
(formerly Hoechst Celanese.)
[0023] The yarns forming the second yarn set can be any of a
variety of materials, depending on the intended end use of the
fabric For example, in one form of the invention the second yarn
set also includes elastomeric synthetic yarns, either alone or in
combination with one or more other types of yarns. For example, the
fill can include other types of elastomeric yarns, polyester,
nylon, natural Taslan polyester, elastomeric/Taslan polyester yarn
combinations, polyester wrapped ELAS-TER.RTM. yarns, combinations
thereof, or any other type of yarn or yarn combination which
achieves the desired end properties. In most forms of the
invention, it will generally be preferred to include other types of
yarns in the second yarn set (either alone or in combination with
an elastomeric synthetic yarn component) in order to provide
particular functional and aesthetic properties to the fabric. For
example, in many cases it will be desirable to use a yarn in the
second yarn set which provides the fabric with a soft hand or the
like (e.g. through the use of a textured or spun yarn and in
particular, one having an overall cross-sectional diameter which is
greater than that of the elastomeric synthetic yarn, so that it
extends outwardly from the fabric to form an aesthetically pleasing
fabric surface.) Alternatively, the second yarn set can be devoid
of elastomeric synthetic yarns, depending on the particular end use
intended for the fabric and physical characteristics desired. In
addition, a single yarn can be inserted in each shed during the
weaving process or a plurality of yarns can be inserted in one or
more of the sheds. Furthermore, it is noted that the elastomeric
yarns can be provided in the fill while other types of yarns are
used to form the warp. However, it is preferred to provide the
elastomeric synthetic yarns in at least the warp direction.
[0024] In a preferred form of the invention particularly useful in
the manufacture of automotive upholstery, the second yarn set
includes a Taslan polyester yarn about 600-2200 denier in size.
This yarn can be used alone to form the second yarn set, or it can
be used in combination with an elastomeric synthetic yarn similar
to or the same as that used in the first yarn set. In such a
combination, the elastomeric synthetic yarn component and the other
yarn component can be combined prior to weaving (e.g. through a
texturing or twisting process or the like), or the two components
can be inserted together during the weaving process, without first
being combined together. Again, the particular arrangement of the
filling yarns will be selected to achieve the physical and
aesthetic properties desired.
[0025] The fabric is desirably woven in a construction wherein at
least some of the warp and fill yarns are locked together by virtue
of the weave construction rather than simply intersecting in the
manner of a plain weave construction. Preferably, the weave
construction used to stabilize the points of intersection is a leno
weave construction or a variation of a leno weave construction. (As
will be appreciated by those having ordinary skill in the art, a
leno weave includes pairs of warp yarns which cross as they
encircle and secure the filling yarns. As used herein, the term
"leno" is intended in its broadest meaning and to include all
variations of leno weave.) In a preferred form of the invention,
all of the warp yarns are woven in a leno fashion; however, fabrics
having only a portion of the warp yarns woven in a leno fashion are
also within the scope of the instant invention. For example, a
pattern of alternating leno and plain woven warp yarns can be
utilized. Alternatively, other weave constructions that secure at
least some of the yarn intersections from relative motion can be
used within the scope of the invention.
[0026] Preferably, at least some of the points of intersection are
also supplementally secured from relative motion with respect to
each other. For example, in a preferred form of the invention, at
least a portion of the yarns used to construct the woven fabric are
thermoplastic, so that they can be melted during a heat setting
operation to secure the points of intersection of yarns in the
respective first and second yarn sets from relative motion. In a
particularly preferred form of the invention, at least some of the
points of intersection are secured by both the particular weave
construction utilized and by a supplemental securement.
[0027] In one aspect of the invention, at least some of the yarns
used to form the fabric are sheath/core bicomponent yarns, having a
sheath component with a lower melting temperature than the core
component. In this way, the fabric can be subjected to a
temperature greater than that of the melting point of the sheath
(but preferably below the melting point of the core component) to
melt the sheath, and when the sheath is re-solidified, it can serve
to bond the woven fabric together at the point of yarn
intersection. To this end, it is preferable to utilize as the
elastomeric synthetic yarn a sheath/core yarn having a sheath which
has a melting temperature which is at least about 30.degree. F.
lower than that of the core. Because of their unique construction,
the fabrics of the invention can be readily and efficiently cut and
sewn without the raveling generally associated with prior art
fabrics.
[0028] The fabric is also designed to be resistant to UV
irradiation, in order that it retains its strength and other
physical characteristics even after extended exposure to UV
irradiation. In particular at least some of the yarns, and
preferably substantially all of the yarns, forming the fabric are
resistant to UV irradiation. In particular, the yarns desirably
retain a substantial portion of their original tensile strength and
elongation characteristics following exposure to high levels of UV
irradiation for extended periods of time. In a preferred form of
the invention, at least one of the first and second yarn sets
contains elastomeric synthetic yarns which are UV resistant. In a
particularly preferred form of the invention, UV-resistant
elastomeric synthetic yarns-are utilized to form the warp yarns of
the fabric. The UV-resistant elastomeric synthetic yarns desirably
retain at least about 80%, and more preferably at least about 90%,
of their original tensile strength upon accelerated exposure to 488
kilojoules of UV irradiation in compliance with SAE testing
standard J 1885. In a particularly preferred form of the invention,
the UV-resistant elastomeric synthetic yarns retain at least about
95% of their tensile strength upon accelerated exposure to UV
irradiation. For example, a sample of an elastomeric synthetic yarn
useful in performing the instant invention was tested prior to
weaving, where it exhibited a tensile strength of approximately 8.9
pounds force and an elongation at break of about 124%, and after
accelerated exposure to UV irradiation at a level of 488 kilojoules
in compliance with SAE testing standard J1885 exhibited a tensile
strength of 7.1 pounds force and an elongation at break of
approximately 115%.
[0029] As mentioned, fabrics of the instant invention are desirably
woven in a leno weave with the elastomeric synthetic yarns forming
at least about 40% by weight of the total fabric, and are woven to
produce a relatively open structure. For example, in a preferred
embodiment of the invention, a fabric is leno woven using a 2250
denier elastomeric monofilament polyester disposed in the fabric at
a weave density of about 20 ends per inch. The filling is desirably
a polyester yarn which is 300 denier or greater in size, and which
may or may not include an elastomeric synthetic yarn component. For
example a 1650 denier Taslan yarn has been found to perform well in
the instant invention. In addition, the use of a 1650 denier Taslan
polyester in combination with a 400 denier elastomeric synthetic
yarn has been found to achieve a fabric having good physical
characteristics. The fill density is desirably from about 4 picks
per inch to about 30 picks per inch. As noted, a plurality of fill
yarns of one or more types may be provided in a single shed.
[0030] The fabrics, which desirably utilize sheath/core bicomponent
yarns as the elastomeric synthetic yarns, are preferably heat
treated to melt the sheath component and secure the first and
second yarns sets at their respective yarn intersections. The yarns
are then allowed to cool so that the melted material re-solidifies
to form a good bond between the yarns of the respective yarn
sets.
[0031] Fabrics made according to the instant invention desirably
retain at least about 50%, and more preferably at least about 70%
of their original breaking strength when measured in the
elastomeric synthetic yarn direction and at least about 50% of
their original breaking strength when measured in the other
generally transverse direction following exposure to a cumulative
irradiation of 225 kilojoules in accordance with SAE Standard J
1885. Preferably, the fabric has an elongation at break in the
elastomeric synthetic yarn direction of at least about 70% before
and after exposure to accelerated levels of UV-irradiation of 225
kilojoules and they retain at least about 50%, and more preferably
at least about 70% of their tensile strength in the elastomeric
synthetic yarn direction following accelerated UV irradiation
exposure. Furthermore, the fabrics have unique combinations of
strength, durability, and dimensional stability as well as
desirable aesthetic properties such as hand. Additionally, the
fabrics made according to the invention can be cut and sewn without
raveling, rendering them easier to use in the production of
occupant support structures than prior art fabrics, and minimizing
fabric waste due to raveling.
EXAMPLES
[0032] Fabrics were prepared as follows and tested for purposes of
comparison according to the tests described below. Each of the
fabrics was produced on a standard rapier weaving machine utilizing
a reed width of 69 inches and a beam width of 69 inches. The
fabrics were woven in the respective manner described, and heat
setting was performed at about 3900 F to bond the intersections of
the yarn sets.
[0033] Sample A was fabricated in a conventional manner, to
resemble a commercially-available product. The fabric was woven in
a leno construction to include oval-shaped elastomeric yarns in the
warp and elastomer/Taslan polyester yarns in the fill. None of the
yarns used were UV stabilized, and the fabric was not heat set in
the manner of the instant invention.
[0034] Sample B was manufactured according to the instant
invention. The fabric was formed in a leno weave construction with
the warp being formed from 1000 denier UV-stabilized ELAS-TER.RTM.
yarns, while the fill included elastomer/Taslan polyester yarns.
The fabric was heat set to melt the sheath of the ELAS-TER.RTM.
yarns and secure the points of intersection between the warp and
fill yarn sets.
[0035] Sample C was manufactured according to the instant
invention. The fabric was formed in a leno weave construction using
2250 denier UV-stabilized ELAS-TER.RTM. yarns in the warp and with
two elastomer/Taslan polyester combination yarns and two natural
Taslan polyester yarns being inserted in alternating fashion in
each shed. In other words, each shed included a filling yarn
combination of one elastomer/Taslan yarn, one natural Taslan yarn,
a second elastomer/Taslan yarn, and a second natural Taslan yarn.
The fabric was heat set according to the instant invention to melt
the ELAS-TER.RTM. yarns, to thereby supplementally secure the
points of intersection between the warp and fill yarn sets.
[0036] Sample D was manufactured according to the instant
invention. The fabric was formed in a leno weave construction using
2250 denier UV-stabilized ELAS-TER.RTM. yarns in the warp and 400
denier ELAS-TER.RTM. wrapped with 70 denier polyester yarn in the
fill. The fabric was heat set according to the instant invention to
melt the ELAS-TER.RTM. yarns, to thereby supplementally secure the
points of intersection between the warp and fill yarn sets.
[0037] Sample E was manufactured according to the instant
invention. The fabric was formed in a leno weave construction using
1000 denier UV-stabilized ELAS-TER.RTM.) yarns in the warp and a
400 denier ELAS-TER.RTM.) wrapped with 70 denier polyester yarn in
the fill. The fabric, was heat set according to the instant
invention to melt the ELAS-TER.RTM. yarns and supplementally secure
the points of intersection between the warp and fill yarn sets.
[0038] The fabric was tested using a Yarn Unravel Test as described
below. The procedure closely followed the Trap Tear Test described
in ASTM D1117-14 and was conducted as follows: Fabric samples were
obtained by cutting 3 inch.times.3 inch swatches of each of the
fabrics to be tested. A Sintech Tensile tester was used having top
and bottom jaws which were 2 inches.times.3 inches. A gauge length
of about .sup.3/inch was used to obtain about 2 inches of yarn
unraveling. The cross head speed was set at 12 inches per minute.
The sample was clamped in the bottom jaws of the tensile tester
first. One yarn was pulled loose one inch and clamped in the upper
jaw of the tensile tester. The machine was started and the five
high readings (as per normal procedures used in the trap tear
procedure referenced above, so that extreme values were eliminated
by the program) were averaged. The fabrics were tested in both the
warp and fill directions, and the mean values of the pounds
strength required to pull the yarns from the fabric were
calculated. The results of the Yarn Unravel Test are listed in the
table below.
1 UNRAVEL TEST SAMPLE WARP MEAN (lbs.) FILL MEAN (lbs.) A 0 0.189 B
8.993 3.811 C 19.418 4.589 D 2.139 1.374 E 0.679 0.634
[0039] As noted above, the fabric manufactured according to
conventional method (i.e. Sample A) offered essentially no
resistance to unraveling in the warp direction, and only slight
resistance in the fill direction, i.e. 0.189 pounds strength. In
contrast, the fabrics made according to the instant invention (i.e.
Samples B-E) provided significantly greater resistance to yarn
unraveling, as evidenced by the significantly higher forces
required to unravel yarns in each of the warp and fill directions.
Preferably, fabric made according to the instant invention
exhibited a mean value of at least about 0.5 pounds strength
resistance to unraveling in each of the warp and fill directions.
Even more preferably, the fabrics had a resistance of at least
about 2 pounds strength in the warp direction and at least about 1
pound in the fill direction. Even more preferably, the fabric had a
resistance of at least about 8 pounds in the warp direction and at
least about 3 pounds in the fill direction. Even more preferable is
a fabric having at least about 15 pounds in the warp direction and
at least about 4 pounds in the fill direction.
[0040] Samples A-E were each also subjected to a Wire Test (as
follows) in both the warp and fill direction, and the mean strength
was calculated in each direction. A hooked wire (similar to a fish
hook) was hooked through the fabric to capture approximately 3-4
ends or picks of the fabric (depending on the type of fabric being
tested and the fabric direction being tested.) The force required
to cause the hooked yarns to pull from the fabric was measured and
recorded. The test was performed five times in each direction, and
the mean values calculated. The results are listed below:
2 WIRE TEST SAMPLE WARP MEAN (lbs.) FILL MEAN (lbs.) A 0.9 3.014 B
81.381 13.451 C 94.248 27.464 D 15.093 10.145 E 4.994 11.247
[0041] As evidenced in the table above, the fabrics made according
to the instant invention exhibited much greater strength than that
of the conventional construction (Sample A). Preferably, fabrics
made according to the instant invention have a resistance of at
least about 4 pounds in the warp and at least about 10 pounds in
the fill, more preferably has a warp resistance of at least about
15 pounds, more preferably at least about 80 pounds, and more
preferably at least about 90 pounds. Similarly, resistance in the
filling is desirably at least about 10 pounds, more preferably at
least about 13 pounds, and even more preferably at least about 25
pounds.
[0042] Samples A-E were further subjected to a Skewer/Tear Test as
follows: a piece of the fabric being tested was inserted within a
slot formed in the side edge of a small metal plate. The slot was
approximately 1/2 inch (.about.1.1 cm) in depth, such that about a
1/2 inch (.about.1.1 cm) section of the edge of the fabric was
contained within the slot. The metal plate included first and
second openings approximately {fraction (3/32)} inch (.about.0.025
cm) in diameter which were spaced apart about 1/4 inch
(.about.0.065 cm) from each other and spaced inwardly from the edge
of the plate about {fraction (7/16)} inch (.about.0.5 cm), so that
the openings overlay the slot formed in the side of the plate. A
handle having first and second prongs extending outwardly therefrom
was provided, with the prongs being spaced apart the same distance
as the openings in the metal plate. After insertion of the fabric
edge into the slot, the prongs were then inserted through the
openings (which extend through the entire dimension of the plate)
such that the fabric was effectively skewered in position within
the slot at a position about {fraction (7/16)} inch (.about.0.5 cm)
inwardly from its edge. The metal plate (holding the first end of
the fabric) and free end of the fabric were then pulled apart by a
machine designed to measure the amount of force required to pull
the {fraction (7/16)} inch (.about.0.5 cm) edge of the fabric loose
from the rest of the fabric structure. The test was performed five
times for each of the warp and fill directions, and the warp and
fill means calculated. The results of this test are listed
below:
3 SKEWER/TEAR TEST SAMPLE WARP MEAN (lbs.) FILL MEAN (lbs.) A 4.532
12.101 B 99.271 66.873 C 44.672 52.995 D 39.993 20.188 E 27.914
28.972
[0043] As illustrated, the fabrics of the instant invention have
superior strength and dimensional stability as compared with those
of the prior art. In fact, it has been found that the superior
dimensional stability and ravel resistance enables the fabrics of
the instant invention to be cut and manipulated in the fabrication
of the end use products, a feature that was heretofore impossible
with the comparable prior art fabrics.
[0044] Samples B, C and D (as described above) were also tested to
determine their "openness", along with a Sample F which was
prepared as follows:
[0045] Sample F was manufactured according to the instant
invention. The fabric was woven in a leno construction using 2250
denier UV-stabilized ELAS-TER.RTM. yarns in the warp and a pick of
natural Taslan polyester and a pick of 400 denier ELAS-TER.RTM. in
each shed of the fill. The fabric was heat set according to the
instant invention to melt the ELAS-TER.RTM. yarns, to thereby
supplementally secure the points of intersection between the warp
and fill yarn sets.
[0046] Five areas of each of the fabrics (each area being 45 mm the
warp direction and 60 mm in the fill direction) were measured to
determine the percent of their total area which constituted open
area. The results were then averaged and recorded below. The number
of openings per 45 mm.times.60 mm unit area were also counted by
computer, and the average for each of the fabrics was calculated.
The results are set forth in the tables below:
4 Sample B C D F Openness Test-Percent Openness of Total Area Area
#1 18.7% 36.9% 44.2% 40% Area #2 19.3% 37.3% 47.8% 39.6% Area #3
18% 37.4% 48.9% 41.1% Area #4 19.7% 39.8% 47.9% 41.2% Area #5 19.4%
40.1% 48.1% 42.5% Average 19.2% 38.3% 47.4% 40.1% Number of
Openings Per Unit Area Area #1 896 316 488 324 Area #2 974 312 488
342 Area #3 953 320 475 334 Area #4 985 298 482 329 Area #5 996 309
484 322 Average 960.8 311 483.4 330.2
[0047] As noted, the fabrics of the invention described have at
least about 15% open area, more preferably at least about 30%, even
more preferably at least about 35%, and even more preferably at
least about 40%. Furthermore, fabrics having at least about 45%
open area can be produced and as indicated by Sample D, have
desirably strength levels to enable their use in a variety of end
use products.
[0048] In contrast, a typical barathea fabric (similar to that
described in commonly-assigned U.S. Pat. No. 5,856,249 described
above) would only have about 5% openness, rather than the
significant openness achieved with the fabrics of the instant
invention. As noted above, this high amount of openness enhances
the comfort characteristics of the fabric, as well as providing a
desirable aesthetic appearance. In addition, despite their high
degree of openness, the fabrics have good strength and dimensional
stability, as evidenced by the Yarn Unravel Test and other strength
tests described above.
[0049] In the specification there has been set forth a preferred
embodiment of the invention, and although specific terms are
employed they are used in a generic and descriptive sense only and
not for purposes of limitation, the scope of the invention being
defined in the claims.
* * * * *