U.S. patent application number 11/326198 was filed with the patent office on 2006-06-01 for composite elastomeric yarns.
This patent application is currently assigned to The Quantum Group, Inc.. Invention is credited to Jeffrey W. Bruner.
Application Number | 20060113033 11/326198 |
Document ID | / |
Family ID | 25104926 |
Filed Date | 2006-06-01 |
United States Patent
Application |
20060113033 |
Kind Code |
A1 |
Bruner; Jeffrey W. |
June 1, 2006 |
Composite elastomeric yarns
Abstract
Disclosed are composite elastomeric yarns comprising a polymeric
core, a thermoplastic polymeric sheath disposed about the core and
fibers disposed about and mechanically anchored in the sheath. The
melting point temperature of the material comprising the sheath is
at least about 10.degree. C. and preferably from about 50.degree.
C. to about 75.degree. C. lower than the melting point temperature
of the material comprising the core. Methods and articles relating
to such yarn are also disclosed.
Inventors: |
Bruner; Jeffrey W.;
(Greensboro, NC) |
Correspondence
Address: |
SYNNESTVEDT & LECHNER, LLP
2600 ARAMARK TOWER
1101 MARKET STREET
PHILADELPHIA
PA
191072950
US
|
Assignee: |
The Quantum Group, Inc.
Colfax
NC
|
Family ID: |
25104926 |
Appl. No.: |
11/326198 |
Filed: |
January 5, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10744028 |
Dec 23, 2003 |
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11326198 |
Jan 5, 2006 |
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10106863 |
Mar 26, 2002 |
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11326198 |
Jan 5, 2006 |
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08775610 |
Dec 31, 1996 |
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11326198 |
Jan 5, 2006 |
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Current U.S.
Class: |
156/296 ;
297/452.1; 428/373 |
Current CPC
Class: |
D02G 3/32 20130101; D02G
3/408 20130101; Y10T 428/2929 20150115; D02G 3/328 20130101 |
Class at
Publication: |
156/296 ;
428/373; 297/452.1 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Claims
1. A composite elastomeric yarn comprising: a thermoplastic
polymeric core; a thermoplastic polymeric sheath disposed about the
core wherein the melting point temperature of the sheath is at
least about 10.degree. C. lower than the melting point temperature
of the core; and fibers mechanically anchored in and disposed about
the sheath.
2. The yarn of claim 1 wherein the core comprises a
monofilament.
3. The yarn of claim 1 wherein the core comprises a plurality of
filaments.
4. The yarn of claim 1 wherein said fibers comprise flaccid textile
materials.
5. The yarn of claim 1 wherein said fibers comprise non-flaccid
fibers.
6. The yarn of claim 1 wherein the fibers are selected from the
group consisting of cotton, carbon, wool, man-made cellulosics,
polyamide, polyester, fluorocarbon polymers, polybenzimidazole,
polyolefins, polysulfide, polyacrylonitriles, polymetaphenylene
isophthalamide, polyvinyl acetate, polyvinyl chloride,
polyvinylidene chloride, fiberglass, poly(vinyl alcohols) and
combinations of two or more of these.
7. The yarn of claim 1 wherein the fibers are physically bonded to
the sheath by means of heating the sheath to a temperature above
the melting point temperature of the sheath but below the melting
point temperature of the core.
8. The yarn of claim 1 wherein the melting point temperature of the
sheath is from about 50.degree. C. to about 75.degree. C. lower
than the melting point temperature of the core.
9. A process of forming a composite elastomeric yarn comprising the
steps of: providing a sheath-core component comprising a
thermoplastic polymeric core and a thermoplastic polymeric sheath
disposed about the core wherein the melting point temperature of
the sheath is at least about 10.degree. C. lower than the melting
point temperature of the core; heating the sheath-core component to
a temperature to at least soften the sheath but below the melting
point temperature of the core; disposing fibers in intimate
mechanical contact about the sheath; and cooling the composite
elastomeric yarn to anchor the fibers in the sheath.
10. The process of claim 9 wherein said disposing step preceeds
said heating step.
11. The process of claim 9 wherein the core comprises a
monofilament.
12. The process of claim 9 wherein the core comprises a plurality
of filaments.
13. The process of claim 9 wherein the sheath-core component is
stretched from about 10% to about 500% beyond its relaxed length
prior to the disposition of fibers about the sheath.
14. The process of claim 9 wherein the fibers are selected from the
group consisting of cotton, carbon, wool, man-made cellulosics,
polyamide, polyester, fluorocarbon polymers, polybenzimidazole,
polyolefins, polysulfide, polyacrylonitriles, polymetaphenylene
isophthalamide, polyvinyl acetate, polyvinyl chloride,
polyvinylidene chloride, fiberglass, poly(vinyl alcohols) and
combinations of two or more of these.
15. The process of claim 9 wherein the melting point temperature of
the sheath is from about 50.degree. C. to about 75.degree. C. lower
than the melting point temperature of the core.
16. A seat assembly, having a seat frame and a low profile seat
suspension stretched across and attached to the frame, the
improvement being that said seat suspension comprises a fabric
comprising composite elastomeric yarn wherein said composite
elastomeric yarn comprises a thermoplastic polymeric core, a
thermoplastic polymeric sheath disposed about the core wherein the
melting point temperature of the sheath is at least about
10.degree. C. lower than the melting point temperature of the core,
and fibers mechanically anchored in and disposed about the
sheath.
17. The seat assembly of claim 16 wherein the seat assembly is
installed in a land, sea or air vehicle.
18. Commercial indoor furniture comprising the seat assembly of
claim 16.
19. Commercial outdoor furniture comprising the seat assembly of
claim 16.
20. Residential indoor furniture comprising the seat assembly of
claim 16.
21. Residential outdoor furniture comprising the seat assembly of
claim 16.
Description
FIELD OF THE INVENTION
[0001] This invention relates to certain composite elastomeric
yarns suitable for use in furniture/seating fabrics, methods for
making said composite elastomeric yarns and articles incorporating
fabrics comprising said composite elastomeric yarns. The composite
elastomeric yarns of the present invention are particularly well
suited for use in indoor and outdoor furniture fabrics for seats,
both bottoms and backs, installed in various forms of ground
transportation such as automobiles, motorcycles, trucks, buses,
trains, etc., as well as various aircraft and marine craft, where a
lightweight combination of strength, comfort and style is
desired.
BACKGROUND OF THE INVENTION
[0002] In the past, elastomeric yarns used to produce fabrics
having elastomeric properties have typically included rubber and
elastomeric polyurethanes, such as spandex, which possess high
coefficients of friction. As a result, they are difficult to handle
in typical textile yarn and fabric manufacturing processes and are
uncomfortable when in direct contact with the human body.
Accordingly, it has been necessary to cover, coat or in some other
manner conceal the rubber or polyurethanes in the yarn or fabric
structure to provide the desired aesthetic, design, comfort, wear
and durability characteristics when used in most apparel, home
furnishings, medical, automotive, air and marine craft
applications, as well as other industrial fabric applications.
[0003] In automotive, air and marine craft applications,
elastomeric yarns have been incorporated in fabrics used to cover
vehicle seats. Vehicle seats found in the various forms of ground,
air and marine transportation have often been constructed from
varying combinations of bulky polyurethane stuffing material or
molded foam cushioning which is then mounted on wire frames or
stamped metal pans and covered with fabric. The fabric is typically
cut and sewn to size to contain and protect the materials contained
within the seat as well as provide a comfortable, durable and
attractive finish suitable for the interior design scheme of the
vehicle. Depending on the combination of materials chosen, springs
or elastic straps are also often used in the seat to provide a
vehicle seating assembly with greater static and dynamic support
characteristics, as well as passenger comfort. In such seating
assemblies, however, the extensive use of foam cushioning, stuffing
material and springs or elastic straps adds significantly to the
weight of the finished product which is undesired in vehicle
applications where fuel economy is often a goal. Further, the use
of varying combinations of these separate components results in
seat assemblies having higher costs of materials and, because of
complicated assembly procedures, greater labor costs as well.
[0004] While thin profile seats have been developed, they have not
provided the aesthetic qualities that are desired in many furniture
fabrics. An example of such thin profile seats is found in Stumpf,
et al. (PCT Application No. PCT/US93/05731), which is incorporated
herein by reference, wherein an office chair is disclosed.
[0005] It is therefore an object of the present invention to
provide a composite yarn having elastomeric characteristics.
[0006] It is another object of the present invention to provide a
composite elastomeric yarn suitable for use in fabrics which offers
support and comfort while allowing for significant reduction in the
need for foam materials, springs or elastic straps.
[0007] It is still another object of the present invention to
provide a composite elastomeric yarn which can accommodate a wide
variety of surface textures and fiber densities.
[0008] It is yet another object of the present invention to provide
a method of forming composite elastomeric yarns which are suitable
for use in supportive and comfortable fabrics which can accommodate
a wide variety of surface textures and fiber densities.
[0009] It is still a further object of the present invention to
provide a method of forming composite elastomeric yarns which are
suitable for use in vehicle seat fabrics.
SUMMARY OF THE INVENTION
[0010] The present invention relates to composite elastomeric
yarns, to methods of making same, and to articles in which such
yarns are used. The yarns of the present invention comprise a
polymeric core, a thermoplastic polymeric sheath disposed about the
core, and fibers disposed about and mechanically anchored in the
sheath. An important aspect of certain embodiments of the present
invention is the requirement that the polymeric core is a
thermoplastic polymeric core and that the melting point temperature
of the material comprising the sheath is at least about 10.degree.
C., and preferably from about 50.degree. C. to about 75.degree. C.,
lower than the melting point temperature of the material comprising
the core.
[0011] The method aspects of the present invention comprise the
steps of: providing a composite elastomeric yarn comprising a
thermoplastic polymeric core and thermoplastic polymeric sheath
disposed about the core wherein the melting point temperature of
the sheath is at least about 10.degree. C. lower than the melting
point temperature of the core; heating the composite elastomeric
yarn to a temperature at or above about the melting point
temperature of the sheath but below the melting point temperature
of the core; disposing fibers in intimate mechanical contact about
the sheath; and cooling the composite elastomeric yarn to
mechanically anchor said fibers in said sheath. In certain
preferred embodiments, the methods further comprise stretching the
composite elastomeric yarn from about 10% to about 500% beyond the
relaxed state prior to the step of disposing said fibers. This
preferred method enhances the ability of the manufacturer to vary
the fiber density and/or bulk of the resulting composite yarn.
[0012] The articles of the present invention-relate to furniture
fabrics, and particularly to seating fabrics, comprising composite
elastomeric yarns for use in seats and backs of chairs, benches and
sofas used in office and/or residential environments or installed
in various forms of ground transportation such as automobiles,
motorcycles, trucks, buses, trains, etc. as well as various
aircraft and marine craft. By using fabrics comprising the
composite elastomeric yarns in vehicle seating assemblies, a fabric
possessing strength, comfort and elasticity can be achieved in
combination with superior aesthetic qualities. In certain preferred
embodiments, thin profile vehicle seating assemblies can be
constructed with fabrics comprising the composite elastomeric yarns
without the need for bulky foam cushions, stuffing material,
springs or rubber straps while maintaining a desirable combination
of support, comfort and appearance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a partially cross-sectional, partially angled view
of a composite elastomeric yarn according to a first embodiment of
the present invention.
[0014] FIG. 2 is partially cross-sectional, partially angled view
of a second embodiment of the present invention having a
multifilament core.
[0015] FIG. 3 is the first view in a sequence of profile views
showing a segment of the interior yarn prior to the disposition of
fibers on the surface of the sheath.
[0016] FIG. 4 is the second view in a sequence of profile views
showing the disposition of fibers on the surface of the sheath of
the segment of FIG. 3 after the interior yarn has been
stretched.
[0017] FIG. 5 is the third view in a sequence of profile views
showing the segment of FIG. 3 after the composite yarn has been
relaxed from a stretched state in which fibers have been disposed
on and anchored to the surface of the sheath.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The Yarns
[0019] As disclosed herein, the preferred composite yarns of the
present invention have improved properties both in high
elongation/low modulus embodiments as well as low elongation/high
modulus embodiments. More specifically, the composite yarns of the
present invention provide an aesthetically pleasing outer surface
in both elongated and relaxed form, improved adherence of surface
fibers to the elastomeric core, and improved abrasion resistance.
Further, the preferred composite yarns of the present invention are
able to lock in and hide electro-conductive yarns in the interior
as well as cover flammable elastomers with non-flammable or fire
resistant fibers to produce elastic yarns which will not burn or
propagate flame spread.
[0020] From an aesthetic perspective, composite yarns of the
present invention can be produced with varying degrees of bulk and
varying moduli depending on the desired application, and can be
brushed in yarn or fabric form resulting in minimal fiber loss as
the surface fibers are mechanically anchored into the yarn core.
When used in fabrics for vehicle seats in automotive, air and
marine craft applications, the combination of properties of the
yarns of the present invention provides the necessary support,
comfort and appearance previously achieved by means of the
combination of foam cushioning, stuffing material, springs, and
elastic straps.
[0021] The composite yarns of the present invention preferably
comprise a thermoplastic polymeric core, a thermoplastic polymeric
sheath disposed about the core, and fibers disposed about and
mechanically anchored in the sheath. FIG. 1 shows generally a
segment of a preferred composite yarn of the present invention 1.
As further shown in FIG. 1, the yarns comprise a core 2, a sheath
3, and fibers 4 disposed about and mechanically anchored into the
sheath. Although the anchored fibers are illustrated in the figures
as short, individual strands of fibers, it should be appreciated
that in certain embodiments the "fibers" may be part of or
incorporated into a yarn disposed about the sheath. In certain
embodiments, the core component of the interior yarn comprises a
thermoplastic polymeric monofilament, while in other embodiments,
as shown in FIG. 2, the core comprises a plurality of thermoplastic
polymeric filaments 5 which can be configured in a number of
alternative forms well known to the art (i.e., bundled, twisted,
braided, etc.).
[0022] The interior yarn of the present invention preferably
comprises a core component and a sheath component. As stated above,
in certain embodiments the core component comprises a monofilament
while in other embodiments the core component comprises a plurality
of filaments. The polymeric material comprising the core, whether
in a monofilament or multifilament embodiment, preferably comprises
a polymer which exhibits a relatively high melting point
temperature. It is preferred that the melting point temperature of
the material comprising the core be in the range of from about
185.degree. C. to about 240.degree. C., and preferably from about
200.degree. C. to about 230.degree. C. By comparison, the polymeric
material comprising the sheath component of the interior yarn
preferably comprises a polymer which exhibits a melting point
temperature at least 10.degree. C. lower than the melting point
temperature of the core material. It is preferred that the melting
point temperature of the material comprising the sheath be in the
range of from about 100.degree. C. to about 200.degree. C., and
preferably from about 160.degree. C. to about 190.degree. C.
[0023] Provided that the relative melting points of the core
material and the sheath material differ by at least about
10.degree. C., the materials comprising the core and the sheath can
be selected from a wide variety of readily available polymers which
exhibit thermoplastic properties. It is preferred, however, that
the melting point temperature differential between the materials
comprising the core and the sheath be from up to about 50.degree.
C. to up to about 75.degree. C. to allow for greater flexibility in
subsequent manufacturing processes. By using materials having
different melting points, the sheath component of the interior yarn
can be heated to a temperature which results in at least the
softening and/or tackifying of the sheath material while the core
component of the interior yarn remains in substantially solid and
oriented form.
[0024] For high modulus/low elongation yarns, the hardness of the
core component of the interior yarn of the present invention, as
measured on the Shore D hardness scale, is preferably from about 38
to about 82, more preferably from about 45 to about 72, and even
more preferably from about 55 to about 63. Although it is
contemplated that numerous polymers may be used as the core
component of the present invention, thermoplastic polymers which
exhibit elastomeric properties are preferred, with elastomeric
polyesters being especially preferred. It will be appreciated by
those skilled in the art that the term "polyester" as used herein
is intended to include polymers which include polyester components,
such as co-polymers of polyesters and other polymeric components,
including graft and block co-polymers. In certain preferred
embodiments, the core component comprises the polyester block
co-polymer sold under the trademark HYTREL.RTM. by E.I. Du Pont de
Nemours & Co., Inc., and even more preferably, HYTREL.RTM.
grade 5556 or 6356. According to preferred embodiments, the core
component consists essentially of polyester, and preferably
polyester selected from the group consisting of polyether esters
and polyester esters, examples of which are HYTREL.RTM. and the
product sold under the trademark ARNITEL.RTM. by D.S.M.
Polymers.
[0025] According to preferred embodiments, the interior yarn
preferably comprises a core having a hardness of about 55 to about
63 on the Shore D hardness scale and comprising a co-polyester
elastomer, and a sheath of a softer, lower melting point elastomer
of having a hardness of about 35 to about 45 on the Shore D
hardness scale.
[0026] The percent elongation of the core at the breaking point is
preferably from about 50% to about 150% beyond its relaxed state,
more preferably from about 80% to about 130% beyond its relaxed
state, and even more preferably from about 100% to about 110%
beyond its relaxed state. The denier range of the core component of
the interior yarn of the present invention is preferably from about
500 to about 2500 and even more preferably from about 800 to about
2000.
[0027] The material comprising the sheath component of the interior
yarn of the present invention is preferably compatible with the
material comprising the core component in order to establish
appropriate bonding to and adherence with the core component. The
hardness of the sheath component of the interior yarn of the
present invention, as measured on the Shore D hardness scale, is
preferably from about 30 to about 40.
[0028] In certain preferred embodiments, additives can be included
in the polymeric material used to form the interior yarn in order
to enhance various properties desired for specific end use
requirements. Such additives include, but are not limited to,
hydrolytic stabilizers, UV light stabilizers, heat stabilizers,
color additives and fixing agents, flame retardants, as well as
electrically conductive materials for dissipation of static
charges.
[0029] The fibers 4 which are disposed about the surface of the
sheath as shown in FIG. 1 generally comprise conventional
non-elastic materials which are often used in apparel, home
furnishings, automotive, aircraft and marine applications, as well
as other industrial and medical applications. It will be
appreciated by those skilled in the art that the fibers 4 which may
be utilized in accordance with the present invention can vary
widely depending on the particular characteristics desired for the
end product. Furthermore, as mentioned above, the fibers may be
single, individual fibers, such as chopped strand, or fibers which
are spun, twisted or otherwise bound together to form a yarn. The
fibers of the present invention are preferably selected from the
group consisting of cotton, carbon, wool, man-made cellulosics
(including cellulose acetate and regenerated cellulose), polyamide,
polyester, fluorocarbon polymers, polybenzimidazole, polyolefins
(including polyethylene and polypropylene), polysulfide,
polyacrylonitriles, polymetaphenylene isophthalamide (such as
NOMEX.RTM.), polyvinyl acetate, polyvinyl chloride, polyvinylidene
chloride and other flaccid textile materials, as well as
non-flaccid fibers such as aramids (KEVLAR.RTM. and NOMEX.RTM.
manufactured by E.I. Du Pont de Nemours & Co., Inc.),
fiberglass, metallic and ultra high strength polyethylenes and high
tenacity polyesters, nylons and poly(vinyl alcohols). These fibers
can also be characterized by type, i.e., spun (ring, friction and
wrap), chenille, and filament (flat, false twist, airjet, stuffer
box, etc.). It will be understood that as used herein fibers can
include both fibers in free form as well as fibers which already
comprise yarns.
[0030] The exterior yarn is preferably disposed about the surface
of the interior yarn by means of the various methods set forth
below wherein the fibers of the exterior yarn are anchored in the
interior yarn. So disposed, the interior yarn and the exterior yarn
are mechanically bonded together so that the resulting composite
elastomeric-yarn exhibits durability and wear resistance while also
providing a wide range of textures and fiber densities depending on
the fibers used and the particular method of application
employed.
[0031] The Methods
[0032] The methods of the present invention relate to the formation
of composite elastomeric yarns. The methods preferably comprise the
steps of: providing a composite elastomeric yarn comprising a
thermoplastic polymeric core and a thermoplastic polymeric sheath
disposed about the core wherein the melting point temperature of
the sheath is at least about 10.degree. C. lower than the melting
point temperature of the core; heating the composite elastomeric
yarn to a temperature above the melting point of the sheath but
below the melting point of the core; disposing fibers in intimate
mechanical contact about the sheath; and cooling the composite
elastomeric yarn to mechanically anchor the fibers to the
sheath.
[0033] The above description in which the heating step is described
prior to the cooling step should not be understood as limiting the
sequence of the steps used according to the present invention.
According to preferred embodiments, for example, the step of
disposing the fibers in intimate contact with the sheath occurs
prior to heating of the composite elastomeric yarn.
[0034] In certain preferred embodiments, as shown in the sequence
of FIG. 3 to FIG. 5, the composite elastomeric yarn will be
stretched from about 10% to about 500% beyond its relaxed length
prior to the disposition of fibers about the sheath.
[0035] The initial step of providing the interior yarn, also
referred to herein as the sheath-core component, can be
accomplished in a variety of ways including forming the sheath-core
component by methods well known to the art or obtaining certain
pre-made interior yarns from other sources. The methods of forming
the sheath-core component include the pulltrusion technique of
forming the core component and then drawing the core component
through a molten bath of the sheath material at a temperature above
that of the melting point temperature of the sheath material but
below that of the melting point temperature of the core material.
Alternatively, the core component can be simultaneously co-extruded
with the sheath component at a temperature appropriate for such
simultaneous co-extrusion in a manner such that the extrudate
comprises a core comprising the higher melting point material and a
sheath comprising the lower melting point material as disclosed by
Himmelreich, Jr. (U.S. Pat. No. 4,469,738) which is incorporated
herein by reference. Another alternative for providing an interior
yarn according to the present invention is a crosshead technique in
which the core of the interior yarn is preformed and is fed through
the center of a crosshead extrusion die wherein the sheath material
is extruded as an outer jacket or covering over the preformed core
material. It will be understood that certain embodiments of the
methods of the present invention will employ a monofilament core,
while in other embodiments of the methods of the present invention
the core comprises a plurality of filaments.
[0036] Another step in the methods of the present invention
comprises heating the interior yarn to a temperature above that of
the melting point temperature of the sheath material but below that
of the melting point temperature of the core material. In so doing,
the sheath material is softened or at least tackified to permit
mechanical bonding with the fibers-subsequently applied. In certain
preferred embodiments, the heating will occur during manufacture of
the composite yarn but prior to incorporation of the yarn into a
fabric. In other embodiments, however, the partially-formed yarn of
the present invention is first incorporated into a fabric
manufacturing process so that the resulting fabric comprising the
yarn of the present invention will be the article that is
heated.
[0037] In certain preferred embodiments, the heated interior yarn
is stretched beyond its relaxed state but within its elastic range
prior to the application of fibers as shown in the sequence of FIG.
3 to FIG. 5. Such stretching allows the resulting composite yarn to
take on varying degrees of bulk and/or density. More specifically,
FIG. 3 shows a segment of the interior yarn comprising a core 2A
and sheath 3A prior to stretching. FIG. 4 shows the subsequent view
of the segment shown in FIG. 3 in which the segment of the interior
yarn has been stretched and fibers 4A have been disposed about the
surface of sheath 3B. Sheath 3B and core 2B are shown having a
thinner profile as a result of the stretched state depicted in FIG.
4. FIG. 5 shows a view subsequent to the view shown in FIG. 4 in
which core 2C and sheath 3C have returned to their original
relaxed, i.e. unstretched, state, and fibers 4B exhibit a greater
density than fibers 4A exhibit in FIG. 4. As shown by the sequence
of FIGS. 3 to 5, when the interior yarn is stretched, any given
interval of the interior yarn in the relaxed form presents a
greater surface area in stretched form on which to accommodate the
application of fibers. Thus, when the composite yarn is then
relaxed to an unstretched state, the density of fibers within any
given interval is greater than if such fibers were applied without
stretching. As a result, the greater degree to which the interior
yarn is stretched prior to the application of fibers, the greater
the bulk in the resulting composite fiber.
[0038] In certain preferred embodiments, the methods of the present
invention further comprise the step of stretching the interior yarn
from about 10% to about 500% beyond its relaxed length prior to the
application of fibers. The optimal degree of stretching will depend
upon the materials used in forming the interior yarn as well as the
intended end use of the composite yarn. By way of example, for high
modulus thermoplastic polyether-ester block copolymer elastomers
such as HYTREL.RTM., the degree of stretching beyond its relaxed
length would be from about 10% to about 40%, and preferably from
about 12% to about 18%. For lower modulus elastomers such as
LYCRA.RTM. spandex manufactured by E.I. Du Pont de Nemours &
Co., Inc., the degree of stretching would typically be from about
300% to about 500%, and preferably from about 350% to about 425%.
In certain preferred embodiments, by stretching the interior yarn
prior to application of the fibers, the resulting composite yarn
when used in fabric manufacturing processes (i.e., weaving,
knitting, etc.) will be able to stretch and recover freely without
significant restrictions imposed by the fibers anchored in the
composite yarn surface. It will be understood that, depending on
the desired manufacturing process and end use, for those
embodiments in which a stretching step is a part, the stretching
step can occur when the interior yarn is in yarn form or when it
has already been processed or partially processed into a
fabric.
[0039] Another step in the methods of the present invention
comprises disposing fibers in intimate mechanical contact about the
heated interior yarn. As stated above, in certain preferred
embodiments, the disposition of fibers will occur while the
interior yarn is in yarn form. In other embodiments, however, the
interior yarn will have already been used in a fabric manufacturing
process so that the application of fibers will be upon the surface
or surfaces of the fabric. It will be understood that the fibers
disposed about the interior yarn can be in the form of free fibers
or in the form of yarn or a combination thereof. Depending on the
fibers to be applied, the desired bulkiness, and the desired end
use, the form of the fibers so disposed will vary and the process
by which the fibers may be disposed includes wrapping, spinning,
twisting, flocking, or any number of other procedures well known to
the art provided, however, that by so disposing the fibers about
the interior yarn said fibers are able to penetrate into at least
the sheath component of the interior yarn so as to achieve a
mechanical bond thereto.
[0040] The heating/bonding step for locking the exterior textile
fibers to the interior yarn preferably takes place directly after
the disposition of the fibers around the interior sheath/core yarn,
and preferably, just before the completed composite yarn is wound
on its supply package. Alternatively, the heating/bonding can take
place in fabric form as well or by heating the interior sheath/core
yarn prior to the disposition of exterior textile fibers.
[0041] The final step in the methods of the present invention
comprises cooling the composite elastomeric yarn so as to effect
the anchoring of the fibers to the interior yarn.
[0042] The Articles
[0043] The resulting composite elastomeric yarns of the present
invention can be used in fabric manufacturing processes for the
formation of fabric articles having a desirable combination of
properties well suited for use in vehicle seats in automotive, air
and marine craft applications. Because of the superior elasticity,
durability and wear resistance of fabrics made from composite
elastomeric yarns of the present invention, as well as the wide
range of textures and fiber densities which can be achieved,
vehicle seats for use in automotive, air and marine craft
applications can be constructed without the need for the additional
use of foam cushioning, stuffing material, springs, elastic straps
or combinations thereof. Such thin profile vehicle seats as
described in Abu-Isa, et al. (U.S. Pat. No. 5,013,089), Abu-Isa, et
al. (U.S. Pat. No. 4,869,554) and Abu-Isa, et al. (U.S. Pat. No.
4,545,614) all of which are incorporated herein by reference, are
examples of preferred articles which can be constructed from
fabrics comprising composite elastomeric yarns of the present
invention.
* * * * *