U.S. patent application number 15/708616 was filed with the patent office on 2018-03-22 for carpet fiber polymeric blend.
The applicant listed for this patent is Mohawk Carpet, LLC. Invention is credited to Dhanraj Jain, John A. Rodgers, James L. Williams.
Application Number | 20180080146 15/708616 |
Document ID | / |
Family ID | 39226738 |
Filed Date | 2018-03-22 |
United States Patent
Application |
20180080146 |
Kind Code |
A1 |
Rodgers; John A. ; et
al. |
March 22, 2018 |
CARPET FIBER POLYMERIC BLEND
Abstract
The invention provides carpet fibers prepared from a blend of
polymeric components, said fiber exhibiting improved properties,
such as improved spinnability and improved fire resistance. The
carpet fibers particularly comprise a majority of polytrimethylene
terephthalate (PTT) and a minority of polyethylene terephthalate
(PET). The invention further provides yarns and carpets prepared
from the inventive fibers, said yarns and carpets likewise
exhibiting improved properties. The invention also provides methods
of improving various physical properties (such as fire resistance,
spinnability, and elongation) of a polymeric composition.
Inventors: |
Rodgers; John A.; (Hixson,
TX) ; Williams; James L.; (Marietta, GA) ;
Jain; Dhanraj; (Kennesaw, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mohawk Carpet, LLC |
Calhoun |
GA |
US |
|
|
Family ID: |
39226738 |
Appl. No.: |
15/708616 |
Filed: |
September 19, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11619075 |
Jan 2, 2007 |
9809907 |
|
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15708616 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D01F 6/92 20130101; D01F
1/07 20130101 |
International
Class: |
D01F 1/07 20060101
D01F001/07; D01F 6/92 20060101 D01F006/92 |
Claims
1. A carpet yarn comprising bulk continuous filaments, said
filaments comprising a polymeric blend of polytrimethylene
terephthalate polymer and about 1% by weight to about 30% by weight
of a polyethylene terephthalate polymer, based on the overall
weight of said carpet yarn.
2. The carpet yarn of claim 1, comprising about 3% by weight to
about 15% by weight of said polyethylene terephthalate polymer,
based on the overall weight of said yarn.
3. The carpet yarn of claim 1, comprising about 5% by weight to
about 15% by weight of said polyethylene terephthalate polymer,
based on the overall weight of said yarn.
4. The carpet yarn of claim 1, comprising about 10% by weight to
about 15% by weight of said polyethylene terephthalate polymer,
based on the overall weight of said yarn.
5. The carpet yarn of claim 1, wherein said polyethylene
terephthalate polymer is a copolymer comprising a content of
1,4-cyclohexane dimethanol comonomers, aromatic dicarboxylic acids,
and combinations thereof.
6. The carpet yarn of claim 1, wherein the yarn exhibits an
increase in elongation in comparison to a carpet yarn comprised of
polytrimethylene terephthalate polymer having an identical
composition with the exception that the comparison carpet yarn has
no polyethylene terephthalate polymer.
7. The carpet yarn of claim 6, wherein said increase in elongation
is from 5% to about 20%.
8. The carpet yarn of claim 6, wherein said increase in elongation
is from about 8% to about 18%.
9. The carpet yarn of claim 1, wherein the polyethylene
terephthalate copolymer comprises recycled polyethylene
terephthalate.
10. The carpet yarn of claim 1, wherein said yarn exhibits improved
ignition characteristics according to ASTM D-2859 in relation to a
like carpet yarn consisting of a polytrimethylene terephthalate
polymer without a polyethylene terephthalate polymer.
11. The carpet yarn of claim 10, wherein said increased ignition
characteristics comprises a pass rate of test ASTM D-2859 of
greater than about 27%.
12. The carpet yarn of claim 10, wherein said increased ignition
characteristics comprises a pass rate of test ASTM D-2859 of at
least about 46%.
13. The carpet yarn of claim 1, wherein said polyethylene
terephthalate polymer comprises a polyethylene terephthalate
homopolymer, a polyethylene terephthalate copolymer, or a
combination thereof.
14. A carpet comprising a carpet yarn according to claim 1.
15. A carpet fiber comprising a polymeric blend of polytrimethylene
terephthalate polymer and about 1% by weight to about 30% by weight
of a polyethylene terephthalate polymer, based on the overall
weight of said fiber, wherein the fiber exhibits an increase in
elongation in comparison to a carpet fiber comprised of
polytrimethylene terephthalate polymer having an identical
composition with the exception that the comparison carpet fiber has
no polyethylene terephthalate polymer.
16. The carpet fiber of claim 15, wherein the fiber comprises about
1% by weight to about 15% by weight of a polyethylene terephthalate
polymer, and said increase in elongation is from 5% to about
20%.
17. The carpet fiber of claim 15, wherein said fiber exhibits
increased fire resistance when tested according to ASTM D-2859 in
relation to a like carpet prepared using a polytrimethylene
terephthalate polymer without the polyethylene terephthalate
polymer.
18. The carpet yarn of claim 1, wherein the polyethylene
terephthalate polymer comprises ethylene terephthalate monomers and
comonomers selected from the group consisting of diethylene glycol,
polyethylene glycol, butylene glycol, polystyrene, vinyltoluene,
halostyrene, dihalostyrene, styrene-butadiene copolymers,
styrene-acrylonitrile copolymers, styrene-acrylonitrile-butadiene
terpolymers, styrene-butadiene-styrene terpolymers,
styrene-isoprene copolymers, aromatic dicarboxylic acids, aliphatic
dicarboxylic acids, glutaric acid, azelaic acid, sebacic acid and
combinations thereof.
19. A carpet comprising a primary back through which a plurality of
carpet yarns art tufted, said carpet yarns comprising bulk
continuous filaments that comprise a polymeric blend of
polytrimethylene terephthalate polymer and about 1% by weight to
about 30% by weight of a polyethylene terephthalate polymer, based
on the overall weight of said carpet yarn.
20. The carpet of claim 19, further comprising a secondary backing.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 11/619,075 filed Jan. 2, 2007, the entire contents of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to polymeric fiber blends, and
particularly fiber blends useful in carpet yarns and carpets. The
invention further relates to methods of improving physical
characteristics of polytrimethylene terephthalate carpet fibers
through preparation of polymeric blends.
BACKGROUND
[0003] Carpets, rugs, mats, and like floor coverings used in home
and industrial applications are typically made from natural fibers
(such as cotton and wool) or synthetic fibers (such as nylon,
polyester, polyolefins, acrylics, rayon, and cellulose acetate).
Synthetic fibers tend to be more favored in carpet manufacture, as
they are generally more commercially acceptable and can be used for
a wider variety of applications.
[0004] Nylon is often used in carpet fiber since it is strong, easy
to dye, and readily available. Nylon carpeting can be
disadvantageous, however, as it generally requires various
treatments in light of its susceptibility to developing static
electric charges and its ease of staining. Carpets made from
polyolefins, such as polypropylene, are very resistant to staining
and are naturally antistatic; however, polypropylene is a more
rigid and less resilient fiber and will not generally maintain its
appearance or shape under prolonged or heavy use, or after repeated
deformations.
[0005] Polytrimethylene terephthalate (PTT) is a favorable
alternative to both nylon and polyolefins. In particular, PTT is
known to provide stain resistance, static resistance, and improved
dyeability while also providing a "wool-like" feel with good
physical performance.
[0006] Carpeting, whether used in home or industrial applications,
preferably has a high degree of fire resistance. Although PTT has
many desirable properties for use in carpet fibers, the degree of
fire resistance exhibited by PTT is not as favorable as other
synthetic fibers. Numerous procedures have been proposed for
improving the fire resistance of melt extruded filaments or fibers
used in the textile industry, such as in carpet construction. One
procedure to improve fire resistance has been to extrude polymeric
fibers or filaments incorporating flame retardant materials into
the raw polymer. This can be undesirable, however, as the
incorporation of such flame retardant materials can result in
finished polymers having undesirable properties, such as altered
color, as well as sensitivity to heat and light. There have been
attempts to overcome such problems while still improving the fire
resistance of polymeric carpet fibers. For example, U.S. Pat. No.
5,024,869 proposes incorporating organic pigments and dyes, such as
carbon black. Despite such efforts, however, there still remains a
need for carpet materials having improved fire resistance.
[0007] Typically, in preparing carpet fiber from PTT, an extruded
fiber is drawn at an elevated temperature and spun into bulk
continuous filament (BCF) yarn. Preparing PTT filament by
conventional spinning processes can have problems, such as frequent
breakouts during spinning and drawing, dusting during production
processes, and formation of yarns having low quality and poor
consistency. Thus, it would also be advantageous to provide a
polymeric carpet material having improved spinnability and like
properties.
SUMMARY OF THE INVENTION
[0008] The present invention provides carpet fibers or filaments
comprising polymeric blends providing improved properties, such as
improved spinnability and improved fire resistance. In particular,
the invention provides polymeric fibers or filaments comprising PTT
blended with one or more additional polymeric components in an
amount such that the finished fiber exhibits improved properties in
relation to a like carpet fiber consisting of PTT alone.
[0009] In one particular embodiment, the carpet fibers of the
invention comprise PTT and polyethylene terephthalate (PET).
Polyethylene terephthalate has natural and permanent stain
resistance as well as strength and abrasion resistance comparable
to nylon. Another benefit of PET in the preparation of carpet fiber
is that the fiber can be made, at least partially, from recycled
plastic, such a drink containers. Only according to the present
invention, however, has it been found that PTT carpet fiber can be
made to have improved properties through incorporation of PET.
[0010] The present invention provides carpet fibers having all of
the desirable properties of PTT yet also including the desirable
properties of PET. What could not have been predicted, however, is
that various properties of PTT fiber can actually be improved by
incorporating PET into the PTT fiber. For example, in one
embodiment, the fire resistance of a PTT fiber can be improved by
incorporating PET into the PTT fiber. In particular, it could not
have been predicted that including even a small amount of PET into
a PTT polymer could improve the fire resistance of a carpet fiber
extruded from the polymeric mixture. In another embodiment, the
spinnability of a PTT fiber can be improved by incorporating PET
into the PTT fiber.
[0011] The present invention provides a further advantage in that
the improved properties can be achieved while also decreasing the
overall cost of the carpet fiber. As noted above, PET is
particularly advantageous in that is can be recovered from
previously prepared materials (e.g., recycled from soda bottles).
Thus, the incorporation of a recycled material into the PTT carpet
fibers provides the desired effect of improving properties, such as
spinnability and fire resistance, while simultaneously reducing the
overall cost of the carpet fiber. Furthermore, this makes the
prepared carpet more "earth friendly." Of course, the invention is
not limited to the use of recycled PET. Rather, virgin PET (or a
mixture of virgin and recycled PET) could be used to spin the novel
carpet fiber. Moreover, the PET used in the carpet fibers of the
invention can be substantially pure PET or can be a copolymer
comprising one or more comonomers.
[0012] In further embodiments, the invention provides yarns,
particularly carpet yarns, prepared from the fibers. Likewise, the
invention provides carpets prepared from the fibers. Such yarns and
carpets are particularly characterized by having improved
spinnability and improved fire resistance.
[0013] In yet another aspect, the invention provides methods of
improving various physical characteristics of polymer compositions.
In certain embodiments, the invention provides methods for
improving the ignition characteristic of polytrimethylene
terephthalate compositions. In one embodiment, the method comprises
preparing said composition to comprise a majority of a
polytrimethylene terephthalate polymer and a minority of a
polyethylene terephthalate polymer, based on the overall weight of
the composition. In further embodiments, the invention provides
methods for improving spinnability of polytrimethylene
terephthalate compositions. In one embodiment, the method comprises
adding an amount of polyethylene terephthalate such that the
polyethylene terephthalate comprises about 3% by weight to about
15% by weight based on the overall weight of the polymer
composition. In specific embodiments, spinnability is improved such
that filament breakage during predetermined spinning conditions is
reduced in comparison to filament breakage under the same
conditions using a polytrimethylene terephthalate polymer
composition without the polyethylene terephthalate. In yet further
embodiments, the invention provides methods for improving the
elongation of polytrimethylene terephthalate polymer compositions.
In one embodiment, the method comprises adding an amount of
polyethylene terephthalate such that the polyethylene terephthalate
comprises about 3% by weight to about 15% by weight based on the
overall weight of the polymer composition. In specific embodiments,
elongation is improved such that there is a measurable percentage
increase in the percent elongation in comparison to the percent
elongation of a polytrimethylene terephthalate polymer composition
without the polyethylene terephthalate.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present inventions now will be described more fully
hereinafter with reference to specific embodiments of the
invention. Indeed, the invention may be embodied in many different
forms and should not be construed as limited to the embodiments set
forth herein; rather, these embodiments are provided so that this
disclosure will satisfy applicable legal requirements. As used in
the specification, and in the appended claims, the singular forms
"a", "an", "the", include plural referents unless the context
clearly dictates otherwise.
[0015] The present invention provides polymeric carpet fibers
exhibiting improved properties. The improved properties arise from
the blend of polymeric materials from which the carpet fibers are
extruded. The polymeric blend comprises at least one first
polymeric material providing properties generally desirable in a
carpet fiber, such as strength, stain resistance, ease of dying,
abrasion resistance, and durability. The polymeric blend further
comprises at least one second polymeric material that, when
combined with the first polymeric material, provides for improved
properties in the fibers extruded from the polymeric blend. In
preferred embodiments, the combination of the polymeric materials
increases the fire resistance of fibers extruded from the polymeric
blend. In further preferred embodiments, the combination of the
polymeric materials increases the spinnability of fibers extruded
from the polymeric blend.
[0016] In one embodiment, the carpet fiber of the invention
comprises PTT as the first polymeric material and PET as the second
polymeric material. The PTT component and the PET component can be
blended in a variety of ratios to arrive at the final polymeric
blend for extrusion into carpet fibers. The carpet fibers of the
invention can be prepared using only PTT and PET in various
combinations. Alternatively, the carpet fibers can be prepared from
a mixture comprising various additional polymers or additives in
addition to the PTT and PET components.
[0017] The improved properties obtainable in an extruded fiber
prepared using the polymeric combinations of the invention can be
determined based upon the relative percentages of the polymeric
components. For example, certain improved properties can be
obtained by using only a relatively small percentage of PET with
the PTT. However, in further embodiments, additional improvements
can be obtained by using relatively larger percentages of PET with
the PTT. Moreover, in further embodiments, using PET in specific
weight ratios with PTT can provide for improved properties wherein
relatively higher PET ratios are used without sacrificing the
improved properties obtained using relatively lower PET
concentrations.
[0018] In one particular embodiment, PTT is the major polymeric
component of the inventive carpet fiber and PET is a minor
polymeric component of the carpet fiber. More specifically, the
carpet fiber comprises greater than 50% by weight of PTT and less
than 50% by weight of PET, based on the overall weight of the
carpet fiber.
[0019] As previously noted, the carpet fiber of the invention is
particularly beneficial in that improved fire resistance can be
achieved with varying amounts of PET added to the PTT carpet fiber.
For example, in one embodiment, the carpet fiber of the invention
can comprise up to about 30% by weight of PET based on the overall
weight of the carpet fiber. In further embodiments, the carpet
fiber can comprise up to about 25% by weight of PET, up to about
20% by weight PET, up to about 15% PET, or up to about 10% PET,
based on the overall weight of the carpet fiber.
[0020] In further embodiments, the inventive carpet fiber can
include PET in specific ranges. For example, in one embodiment, the
carpet fiber can comprise from about 1% by weight to about 30% by
weight of PET, based on the overall weight of the carpet fiber. In
further embodiments, the carpet fiber can comprise from about 3% to
about 20% by weight of PET, about 5% to about 15% weight of PET,
about 7% to about 15% by weight of PET, or about 10% to about 15%
by weight of PET, based on the overall weight of the carpet
fiber.
[0021] In further embodiments, the carpet fiber of the invention is
particularly beneficial in that improved spinnability can be
achieved with varying amounts of PET added to the PTT carpet fiber.
For example, in one embodiment, the carpet fiber of the invention
can comprise about 1% to about 20% by weight of PET, about 2% to
about 18% by weight of PET, about 3% to about 15% by weight of PET,
about 5% to about 15% by weight of PET, or about 7% to about 15% by
weight of PET based on the overall weight of the carpet fiber.
[0022] The PET component of the inventive carpet fiber can comprise
a PET homopolymer. In further embodiments, the PET component can
comprise a copolymer, wherein one or more different monomers can be
included. Any comonomer recognized as being useful in preparing a
polymer useful as a carpet fiber could be used according to the
present invention, particularly any comonomer useful for imparting
useful properties to a formed polymer, such as improved
spinnability or improved fire resistance.
[0023] In one particular embodiment, the PET used in preparing the
inventive carpet fiber is a copolymer comprising ethylene
terephthalate monomers and 1,4-cyclohexane dimethanol (CHDM)
monomers. Preferably, the copolymer comprises a majority of
ethylene terephthalate monomers and a minority of CHDM monomers. A
PET polymer including a percentage of CHDM may be known as
PETG.
[0024] In specific embodiments, the PET component of the invention
comprises up to about 30 mole % of CHDM comonomers. In still
further embodiments, the PET component of the invention comprises
up to about 25 mole %, about 20 mole %, about 15 mole %, about 10
mole %, about 5 mole %, about 4 mole %, about 3 mole %, about 2
mole %, or about 1 mole % of CHDM comonomer.
[0025] In addition to CHDM, the PET component of the invention can
comprise further monomeric or polymeric units. In particular
embodiments, the PET component of the invention comprises
components such as those commonly found in PET used in bottling
compositions. For example, the further units can comprise various
diacids or diols. In specific embodiments, the further units can
comprise one or more isophthalic acids, including sulfonated
isophthalic acids. Still further examples of monomeric or polymeric
units useful in PET according to the invention include diethylene
glycol, polyethylene glycol, butylene glycol, polystyrene,
vinyltoluene, halostyrene, dihalostyrene, styrene-butadiene
copolymers, styrene-acrylonitrile copolymers,
styrene-acrylonitrile-butadiene terpolymers,
styrene-butadiene-styrene terpolymers, styrene-isoprene copolymers,
aromatic dicarboxylic acids (e.g., 5-sodium sulfoisophthalic acid),
aliphatic dicarboxylic acids (e.g., adipic acid and itaconic acid),
glutaric acid, azelaic acid, sebacic acid and combinations thereof.
In addition to these monomeric or polymeric units, branching agents
like trimesic acid, pyromellitic acid, trimethylolpropane and
trimethylolethane, and pentaerythritol may be used.
[0026] These monomeric or polymeric units may be included in the
PET component that is added to the PTT. In further embodiments,
such monomeric or polymeric units may be incorporated directly into
the PTT composition separate from the PET component. Such
components can be incorporated using techniques known in the art,
such as, condensation polymerization techniques.
[0027] Similarly, the PTT component of the inventive carpet fiber
polymer can comprise a PTT homopolymer or can comprise a copolymer
(e.g., formed of trimethylene terephthalate monomers and one or
more comonomers). In a preferred embodiment, the PTT used in the
invention comprises a PTT homopolymer.
[0028] PTT is a polyester, the acid component of which is
terephthalic acid and the diol component of which is
1,3-propanediol. Non-limiting examples of further copolymer
components that may be used in the PTT according to the invention
include ester-forming monomers such as 5-sodium sulfoisophthalic
acid, 5-potassium sulfoisophthalic acid, 4-sodium
sulfo-2,6-naphthalenedicarboxylate,
tetramethylphosphonium-3,5-dicaroboxybenzenesulfonate,
tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate,
tributylmethylphosphonium 3,5-dicarboxybenzenesulfonate,
tetrabutylphoshonium 2,6-dicarboxynaphthalene-4-sulfonate,
tetramethylphosphonium 2,6-dicarboxynaphthalene-4-sulfonate,
ammonium 3,5-dicarboxybenzenesulfonate, 1,2-butanediol,
1,3-butanediol, 1,4-butanediol, neopentyl glycol,
1,5-pentamethylene glycol, 1,6-hexamethylene glycol, heptamethylene
glycol, octamethylene glycol, decamethylene glycol, dodecamethylene
glycol, 1,4-cyclohexanediol, 1,3-cyclohexanediol,
1,2-cyclohexanediol, 1,4-cyclohexanedimethanol,
1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, oxalic acid,
malonic acid, succinic acid, glutaric acid, adipic acid,
heptanedioic acid, octanedioic acid, sebacic acid, dodecanedioic
acid, 2-methylglutaric acid, 2-methyladipic acid, fumaric acid,
maleic acid, itaconic acid, 1,4-cyclohexanedicarboxylic acid,
1,3-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic
acid.
[0029] Additionally, the PTT component can comprise PTT belonging
to one or more different types of PTT polymer. For example, the PTT
polymer can comprise SORONA.RTM. PTT (available from E.I. Du Pont
de Nemours), CORTERRA.RTM. PTT (available from Shell Chemicals),
other PTT polymers, or combinations thereof. PTT is generally
produced by the polycondensation reaction of purified terephthalic
acid (PTA) and 1,3-propanediol (PDO). CORTERRA.RTM. PTT is produced
solely by chemical reaction, while SORONA.RTM. PTT is biochemically
produced using PDO obtained by bacterial metabolism of glucose.
[0030] The polymeric compositions of the present invention may
further comprise other components, such as, without limitation,
finishing agents, delusterants, viscosity boosters, optical
brighteners, matting agents (e.g., titanium oxide), thermal
stabilizing agents (e.g., phosphorous compounds), anti-oxidative
agents (e.g., hindered phenol), anti-static agents, pigments,
ultra-violet blocking agents, and combinations thereof. See, for
example, U.S. Pat. No. 6,921,803, which is incorporated herein by
reference in its entirety.
[0031] The usefulness of the inventive carpet fiber polymeric blend
is particularly surprising in that the fire resistance of the PTT
carpet fiber is increased through addition of another polymeric
component. Accordingly, while traditional flame retardants could
still be included in the inventive carpet fiber, increased fire
resistance is achieved in the present invention without the
necessity of such traditional flame retardants. Thus, the present
invention provides a carpet fiber that, through the incorporation
of a PET component, provides a carpet fiber exhibiting increased
fire resistance in comparison to a like carpet fiber without
PET.
[0032] Increased fire resistance, in one embodiment, is exemplified
by improvement in an ignition characteristic of the carpet fiber,
or a carpet prepared using the carpet fiber. One test used to
evaluate fire resistance is ASTM D-2859 (also known as the
"Methenamine Pill Test"), which provides a standardized method for
the determination of the flammability of finished textile floor
covering materials when exposed to an ignition source under
controlled laboratory conditions. Specifically, a 9- by 9-inch
steel frame with an 8-inch-diameter hole is placed over a 12- by
12-inch carpet sample. A methenamine pill is then placed in the
center and ignited. To pass the test, the charred area caused by
ignition of the pill must not extend to within 1 inch of the hole's
edge at any point for a specified number of samples.
[0033] As further described in Example 1, a carpet prepared using
the inventive carpet fiber exhibits improved ignition
characteristics in comparison to a carpet prepared from PTT fibers
alone. Accordingly, in another embodiment, the present invention
also provides a method of increasing the fire resistance of a
carpet fiber. More specifically, the invention provides a method
for improving the ignition characteristic of a carpet fiber
according to ASTM D-2859.
[0034] In further embodiments, the polymeric combinations according
to the invention provide carpet fiber having improved spinnability.
As used herein, "improved spinnability" includes, without
limitation, improving the continuity of a spinning process,
reducing fiber or filament breakage, reducing dusting (or formation
of dust) during spinning, and reducing fiber or filament
hairiness.
[0035] Thus, in one aspect, the invention is directed to methods
for improving the spinnability of a PTT polymer composition. In
specific embodiments, the method comprises adding PET to the PTT in
an amount of PET effective for improving the spinnability of the
polymer composition. The PET concentration useful in the method can
be in the ranges described herein in relation to the inventive
composition. In preferred embodiments, spinnability is improved
such that filament breakage during predetermined spinning
conditions is reduced in comparison to filament breakage under the
same conditions using a PTT composition without the PET.
[0036] Particularly, the polymeric combination of the invention is
useful for improving spinnability of a PTT composition by reducing
breakage or fiber hairiness, or both, of a PTT fiber or filament.
In specific embodiments, fiber breakage may be reduced by more than
10%, more than 20%, more than 30%, more than 40%, more than 50%,
more than 60%, or more than 70%. In further embodiments, fiber
breakage may be reduced by about 10% to about 70% or about 30% to
about 70%.
[0037] Improved spinnability of the PTT fiber is further
exemplified by a measurable increase in the percent elongation of
PTT fiber incorporating PET. The percent elongation of the PTT
fiber directly relates to the spinnability of the fiber because a
greater percentage elongation is a key indicator of the toughness
of the fiber (i.e., a tougher fiber, when under stress, will be
able to elongate--or stretch--rather than break). Tougher fibers
spin better in light of their increased ability to resist breakage.
In specific embodiments, the percent change in elongation can be
evaluated as the percentage elongation of a fiber according to the
invention comprising a combination of PTT and PET in comparison to
a fiber formed of PTT without PET. Preferably, the inventive fiber
exhibits a percent change (increase) in elongation in the range of
about 5% to about 20% in comparison to a PTT fiber without PET. In
further embodiments, the inventive fiber exhibits a percent change
(increase) in elongation in the range of about 8% to about 18%, or
about 10% to about 18%.
[0038] In another aspect, the invention provides methods for
improving the elongation a PTT polymer composition. In specific
embodiments, the method comprises adding PET to the PTT in an
amount of PET effective for improving the elongation of the polymer
composition. The PET concentration useful in the method can be in
the ranges described herein in relation to the inventive
composition.
[0039] In one particular embodiment, the methods of the invention
comprises adding an amount of PET to a PTT composition and
extruding said PTT and PET blend to make a carpet fiber. The PET
component and the PTT component can be dry blended prior to feeding
the blend to an extruder. Alternatively, the polymeric components
may be fed directly to the extruder in any order provided there is
sufficient residence time in the extruder to assure thorough
essentially homogeneous mixing of the polymeric components.
Moreover, a preblended, essentially homogeneous mixture of
polymeric components may also be fed to an extruder.
[0040] Methods for extruding and spinning PTT are known in the art.
See, for example, U.S. Pat. Nos. 6,284,370, 6,423,407, 6,620,502,
6,682,815, 6,692,671, 6,752,945, and 6,921,803, all of which are
incorporated herein by reference in their entirety.
[0041] The polymeric blend can be extruded to have any shape or
dimension suitable to polymeric carpet fibers. Moreover, the carpet
fibers can undergo any post-spinning processes generally recognized
as useful in the preparation of polymeric carpet fibers. By
"fibers", reference is made to items, recognized in the art as
fibers, such as continuous filaments, monofilaments, staple fibers,
and the like. The fibers can be round or have other shapes, such as
octalobal, delta, sunburst (also known as sol), scalloped oval,
trilobal, tetra-channel (also known as quatra-channel), scalloped
ribbon, ribbon, starburst, and the like. The fibers may also be
solid, hollow, or multi-hollow. The fibers can be used to make
yarns, and the fibers or yarns can be used to prepare a number of
materials, particularly carpets, rugs, mats, and the like.
[0042] In one embodiment, the invention provides yarns prepared
using the fibers described herein. The yarns may be prepared
according to any method for preparing yarns recognized in the art
as being useful therefore. For example, the yarn of the invention
could be partially oriented yarn, spun drawn yarn, textured yarn,
friction false-twisted yarn, and bulk continuous filament ("BCF")
yarn. Partially oriented and friction false-twisted yarns of PTT
are described in U.S. Pat. No. 6,287,688 and U.S. Pat. No.
6,333,106; BCF yarns are described in U.S. Pat. No. 5,645,782, U.S.
Pat. No. 6,109,015, and U.S. Pat. No. 6,113,825, all of the above
being incorporated herein by reference. Preferred steps in
preparing BCF yarn includes spinning (e.g., extruding, cooling, and
coating filaments), single stage or multi-stage drawing (such as
with heated rolls, heated pin or hot fluid assist) at a defined
temperature and draw ratio, annealing, bulking, entangling,
optionally relaxing, and winding the filaments on a package for
subsequent use.
[0043] Yarns prepared according to the present invention exhibit
physical properties similar to the properties of yarns prepared
from fibers consisting of PTT as the only polymeric component.
Table 1 provides a comparison of tenacity (grams/denier) and
elongation (%) for yarns according to the present invention (a
blend of PTT and 15% by weight PET) and yarns made of PTT fibers.
The comparison includes BCF yarn, non-heat set (NHS) yarn, and heat
set (HS) yarn.
TABLE-US-00001 TABLE 1 Yarn BCF Yarn NHS Yarn HS Yarn Property PTT
PTT/15% PET PTT PTT/15% PET PTT PTT/15% PET Denier 1469 1470 3005
3007 3199 3203 Tenacity 2.04 2.08 1.9 2.01 1.7 2.1 Elongation 43.19
43.4 48.98 49.02 55.33 62.18
As seen above, yarns prepared according to the present invention
exhibited similar physical properties to yarns of like size
(denier) prepared using fibers formed with PTT as the only
polymeric component. In fact, in each case, the inventive yarns
exhibited increased tenacity.
[0044] The fibers of the invention can likewise be made into staple
fibers of varying lengths. Such staple fibers can be used for a
variety of products, including carpets.
[0045] In another embodiment of the invention, carpets, rugs, mats,
and the like, can be prepared using the inventive fibers. Any
method of preparing a carpet from a fiber known in the art could be
used in preparing carpets according to the invention. For example,
BCF yarns are typically used to prepare all types of carpets, as
well as textiles, and methods of preparing carpets from BCF yarn
are described in the foregoing references. Typically, a number of
yarns are cable twisted together and heat set in a device such as
an autoclave, and then tufted into a primary backing. Latex
adhesive and a secondary backing are then applied. Carpets
according to the present invention can likewise be made from
non-BCF yarns, such as spun yarns.
[0046] The fibers of the present invention are particularly useful
in the preparation of carpets arising from the increased fire
resistance of the fibers. Accordingly, a carpet according to the
present invention likewise has an increased fire resistance. More
particularly, a carpet according to the present invention (i.e.,
formed from fibers comprising a blend of PTT and PET) exhibits an
improved ignition characteristic according to ASTM D-2859 in
comparison to a carpet prepared from fibers comprising PTT
alone.
[0047] The present invention will be further illustrated by the
various examples. The following examples are provided to illustrate
specific embodiments of the invention and are not to be construed
as limiting the scope of the invention. Rather, various further
embodiments, modifications, and equivalents thereof are encompassed
by the present invention.
EXAMPLE 1
Comparison of Ignition Characteristic of Carpet Samples
[0048] The effect of including PET in a PTT fiber-based carpet was
evaluated by comparing the ignition characteristic of various
carpet samples. The carpet samples were evaluated according to the
standards of ASTM D-2859 using the Methenamine Pill Test.
[0049] Test sample 1 was carpet prepared with fibers consisting of
PTT as the only polymeric component. Test sample 2 was a carpet
according to the present invention prepared using fibers comprising
PTT blended with 15% by weight PET, based on the overall weight of
the fibers. The PET comprised a PET/CHDM copolymer available from
Eastman Chemical under the product name F80CC (instrinsic viscosity
of 0.80+/-0.02 dL/g). Test sample 3 was a carpet prepared with
fibers consisting of PTT as the only polymeric component and
including the flame retardant TINUVIN.RTM. FR (available from
CIBA.RTM. Specialty Chemicals).
[0050] A number of tests were performed on all three samples, and
upon completion of each test, the sample was given a score of
either "pass" or "fail". The results of the tests performed on the
carpet samples are provided below in Table 2.
TABLE-US-00002 TABLE 2 Number Number Pass Sample Fiber Composition
of Tests of Pass Percentage PTT alone 128 34 26.6% PTT with 15% by
wt. PET 64 30 46.9% PTT with TINUVIN .RTM. FR 64 9 14.1%
[0051] As seen from the results provided in Table 2, carpet
prepared according to the present invention significantly out
performs carpet prepared from fibers consisting of PTT as the sole
polymeric component. Moreover, the inventive carpet also out
performed carpet prepared from fibers consisting of PTT fiber
including a commercial flame retardant.
EXAMPLES 2-5
Spinnability of SORONA.RTM. PTT with Varying PET Concentrations
[0052] Spinnability of SORONA.RTM. PTT resin using PTT alone and
varying concentrations of PET was evaluated. Spinning conditions
are provided below in Table 3. Generally, spinning was carried out
under the conditions provided below in Table 3, and break and
elongation properties were evaluated. In particular, note was made
of the number of breaks per hour of spinning, the percent change in
the number of breaks per hour, the percent elongation of the spun
filament, and the percent change in elongation. These properties
are summarized for each example in Table 4 below. Changes in breaks
per hour and elongation are compared as the compositions
incorporating PET in comparison to the control using no PTT
(Example 2). As used herein, a breakout is defined as any unplanned
of a continuous threat-line being produced requiring restringing of
the thread-line on the position faceplate.
TABLE-US-00003 TABLE 3 Condition Example 2 Example 3 Example 4
Example 5 PET Concentration 0% 3% 5% 7% Feed Tension (g) 275 265
270 260 Draw Tension (g) 1050 1041 1070 1040 Transport Roll 56 56
59 59 Speed (mpm) Cooling Drum 83 83 83 83 Speed (mpm) Winder Speed
(mpm) 2751 2751 2751 2751 Screw Speed (rpm) 37.3 37.8 37.8 37.8
Melt Head 115 115 115 115 Pressure (bar) Melt Head 255 255 255 255
Temperature (.degree. C.)
TABLE-US-00004 TABLE 4 Condition Example 2 Example 3 Example 4
Example 5 PET Concentration 0% 3% 5% 7% Number of breaks per 1.243
0.443 0.392 hour % change of breaks -64.36 -68.46 per hour %
elongation 41.08 45.24 45.04 44.37 % change in elongation 10.13
9.64 8.01
EXAMPLE 6
Spinnability of SORONA.RTM. PTT with 15% PET
[0053] In a further example, the spinnability of SORONA.RTM. PTT
with 15% PET was evaluated using the same methods as described
above. Over the testing period, zero breaks were recorded. The
percent elongation of the PTT polymer with 15% PET was 51.12%,
indicating a 18.01% change in elongation percentage over PTT with
no PET added.
[0054] Many modifications and other embodiments of the inventions
set forth herein will come to mind to one skilled in the art to
which these inventions pertain having the benefit of the teachings
presented in the foregoing descriptions. Therefore, it is to be
understood that the inventions are not to be limited to the
specific embodiments disclosed and that modifications and other
embodiments are intended to be included within the scope of the
appended claims. Although specific terms are employed herein, they
are used in a generic and descriptive sense only and not for
purposes of limitation.
* * * * *