U.S. patent application number 16/404701 was filed with the patent office on 2019-11-28 for linear bi-component filament, fiber, or tape, and method of using thereof.
The applicant listed for this patent is Nano and Advanced Materials Institute Limited. Invention is credited to Chenmin LIU, Shengbo LU, Yong ZHU.
Application Number | 20190360125 16/404701 |
Document ID | / |
Family ID | 68613872 |
Filed Date | 2019-11-28 |
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United States Patent
Application |
20190360125 |
Kind Code |
A1 |
ZHU; Yong ; et al. |
November 28, 2019 |
LINEAR BI-COMPONENT FILAMENT, FIBER, OR TAPE, AND METHOD OF USING
THEREOF
Abstract
The invention provides a linear or substantially linear
bi-component filament, fiber, or tape including a first elastomeric
component having a cross-sectional area of at least greater or
lower than approximately 50 percent of the filament, fiber, or
tape, and having a glass transition temperature of approximately
-125 degrees to -10 degrees Celsius; and a second shape-memory
polymeric component having a cross-sectional area of at least lower
or greater than approximately 50 percent and being selected from
one or more of a thermoplastic polyester-based or polyether based
shape memory polyurethane. The second shape-memory polymeric
component is positioned within the bi-component filament, fiber, or
tape, such that a region of the second shape-memory polymeric
component is asymmetrically disposed with respect to a central core
of the bi-component filament, fiber, or tape. The second
shape-memory polymeric component has a selectively engineered shape
recovery temperature T.sub.r between approximately 25.degree. C.
and 90.degree. C.
Inventors: |
ZHU; Yong; (Hong Kong,
HK) ; LIU; Chenmin; (Hong Kong, HK) ; LU;
Shengbo; (Hong Kong, HK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nano and Advanced Materials Institute Limited |
Hong Kong |
|
HK |
|
|
Family ID: |
68613872 |
Appl. No.: |
16/404701 |
Filed: |
May 6, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62762815 |
May 22, 2018 |
|
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|
62702337 |
Jul 23, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D10B 2401/061 20130101;
D10B 2331/10 20130101; D10B 2331/04 20130101; D01F 8/16 20130101;
D01F 8/04 20130101; D01D 5/22 20130101; D01F 8/14 20130101; D10B
2401/046 20130101 |
International
Class: |
D01F 8/14 20060101
D01F008/14 |
Claims
1. A linear bi-component filament, fiber, or tape comprising: a
first elastomeric component having a cross-sectional area of at
least greater than approximately 50 percent of the filament, fiber,
or tape, and having a glass transition temperature of approximately
-125 degrees to -10 degrees Celsius; a second shape-memory
polymeric component having a cross-sectional area of at least lower
than approximately 50 percent and being selected from one or more
of a thermoplastic polyester-based or polyether based shape memory
polyurethane, wherein said polyester based polymer comprises a
polycaprolactone-based polymer, wherein the second shape-memory
polymeric component is positioned within the bi-component filament,
fiber, or tape, such that a region of the second shape-memory
polymeric component is asymmetrically disposed with respect to a
central core of the bi-component filament, fiber, or tape, and
wherein the shape memory polymer has a selectively engineered shape
recovery temperature T.sub.r between approximately 25.degree. C.
and 90.degree. C. wherein the first elastomeric component is more
elastic than that of the second shape-memory polymeric component at
or lower than the selectively engineered shape recovery
temperature.
2. A linear bi-component filament, fiber, or tape comprising: a
first elastomeric component having a cross-sectional area of at
least lower than approximately 50 percent of the filament, fiber,
or tape, and having a glass transition temperature of approximately
-125 degrees to -10 degrees Celsius; a second shape-memory
polymeric component having a cross-sectional area of at least
greater than approximately 50 percent and being selected from one
or more of a thermoplastic polyester-based or polyether based shape
memory polyurethane, wherein said polyester based polymer comprises
a polycaprolactone-based polymer, wherein the second shape-memory
polymeric component is positioned within the bi-component filament,
fiber, or tape, such that a region of the second shape-memory
polymeric component is asymmetrically disposed with respect to a
central core of the bi-component filament, fiber, or tape, and
wherein the shape memory polymer has a selectively engineered shape
recovery temperature T.sub.r between approximately 25.degree. C.
and 90.degree. C. wherein the first elastomeric component is more
elastic than that of the second shape-memory polymeric component at
or lower than the selectively engineered shape recovery
temperature.
3. The linear bi-component filament, fiber, or tape of claim 1,
wherein the filament, fiber, or tape is configured to assume a
substantially helical configuration upon elongation of
approximately 50% to approximately 300%, with the coil number per
centimeter increasing with the increase of the elongation
percentage or the time period of elongation.
4. The linear bi-component filament, fiber, or tape of claim 2,
wherein the filament, fiber, or tape is configured to assume a
substantially helical configuration upon elongation of
approximately 50% to approximately 300%, with the coil number per
centimeter increasing with the increase of the elongation
percentage or the time period of elongation.
5. The linear bi-component filament, fiber, or tape of claim 1,
wherein the filament, fiber, or tape is configured to assume a
substantially helical configuration upon elongation of
approximately 50% to approximately 300%, wherein the coil diameter
is from 0.5 to 7 mm.
6. The linear bi-component filament, fiber, or tape of claim 2,
wherein the filament, fiber, or tape is configured to assume a
substantially helical configuration upon elongation of
approximately 50% to approximately 300%, wherein the coil diameter
is from 0.5 to 7 mm.
7. The linear bi-component filament, fiber, or tape of claim 1,
wherein the filament, fiber, or tape is configured to assume a
substantially helical configuration upon elongation of
approximately 50% to approximately 300%, wherein number of the
turns per cm is from 7 to 32.
8. The linear bi-component filament, fiber, or tape of claim 2,
wherein the filament, fiber, or tape is configured to assume a
substantially helical configuration upon elongation of
approximately 50% to approximately 300%, wherein the number of
turns per cm is from 7 to 32.
9. The linear bi-component filament, fiber, or tape of claim 1,
wherein the bi-component filament, fiber, or tape resumes a
substantially linear shape upon heating to the selectively
engineered shape recovery temperature T.sub.r.
10. The linear bi-component filament, fiber, or tape of claim 2,
wherein the bi-component filament, fiber, or tape resumes a
substantially linear shape upon heating to the selectively
engineered shape recovery temperature T.sub.r.
11. The linear bi-component filament, fiber, or tape of claim 1,
wherein the shape memory polymer is polycaprolactone-based shape
memory polymer with an average molecular number of 10000.
12. The linear bi-component filament, fiber, or tape of claim 2,
wherein the shape memory polymer is polycaprolactone-based shape
memory polymer with an average molecular number of 10000.
13. The linear bi-component filament, fiber, or tape of claim 1,
wherein the polycaprolactone-based shape memory polymer is
polycaprolactone diol-based shape memory polymer having hard
segments selected from 4,4'-Methylenebis(phenylisocyanate),
1,4-Butanediol or N,N-bis(2-hydroxyethyl)-isonicotinamide.
14. The linear bi-component filament, fiber, or tape of claim 2,
wherein the polycaprolactone-based shape memory polymer is
polycaprolactone diol-based shape memory polymer having hard
segments selected from 4,4'-Methylenebis(phenylisocyanate),
1,4-Butanediol or N,N-bis(2-hydroxyethyl)-isonicotinamide.
15. The linear bi-component filament, fiber, or tape of claim 1,
wherein the first elastomeric component is in a range of 10 to 90
wt. % of the total weight of the bi-component filament, fiber, or
tape while the second shape-memory polymeric component is in a
range of 90 to 10 wt. % of the total weight of the bi-component
filament, fiber, or tape, wherein the weight ratio between the
first elastomeric component and the second shape-memory polymeric
component is 1-9:9-1 so long as the positioning of the first
elastomeric component and the second shape-memory polymeric
component with respect to the cross-sections along the bi-component
filament, fiber, or tape remains asymmetrical.
16. The linear bi-component filament, fiber, or tape of claim 2,
wherein the first elastomeric component is in a range of 10 to 90
wt. % of the total weight of the bi-component filament, fiber, or
tape while the second shape-memory polymeric component is in a
range of 90 to 10 wt. % of the total weight of the bi-component
filament, fiber, or tape, wherein the weight ratio between the
first elastomeric component and the second shape-memory polymeric
component is 1-9:9-1 so long as the positioning of the first
elastomeric component and the second shape-memory polymeric
component with respect to the cross-sections along the bi-component
filament, fiber, or tape remains asymmetrical.
17. The linear bi-component filament, fiber, or tape of claim 1,
wherein the first elastomeric component comprises one or more of
polyester and polyether-based polyurethanes.
18. The linear bi-component filament, fiber, or tape of claim 2,
wherein the first elastomeric component comprises one or more of
polyester and polyether-based polyurethanes.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priorities from U.S.
provisional patent application Ser. No. 62/762,815 filed May 22,
2018 and U.S. provisional patent application Ser. No. 62/702,337
filed Jul. 23, 2018, and the disclosures of which are incorporated
herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a substantially linear
bi-component filament, fiber, or tape, and method of using
thereof.
BACKGROUND
[0003] Shape memory polymers are materials that have a first,
"permanent" configuration and a second "temporary" configuration
that results from deformation of the material. Upon receiving an
external stimulus, such as heat, solvent, electrical current,
light, magnetic field, or change of pH a thermal stimulus, the
material returns to its "permanent configuration". That is, the
material "remembers" its original shape and returns to that shape
after undergoing the external stimulus.
[0004] So far, the most well-studied SMP is the thermally-triggered
SMP which typically includes two phases: i) hard phase that
determines the permanent configuration and ii) soft phase that
permits the formation of the temporary shape. The shape changing
mechanism between the hard and soft phase requires an elastic
network which can recover the material to the previous strain state
while applying the stimulus, and switching elements that can
reversibly change from inelastic to mobile at a transition
temperature, that is glass transition temperature (T.sub.g) or
melting temperature (T.sub.m). For a typical SMP production, it
usually chemically combines the elastic network and switching
structural elements to polymers or macromolecules. However, there
are some disadvantages such as those chemically cross-linked SMPs
are unrecyclable, aging over time, or complicated chemical
processes for large scale production.
[0005] Bi-component filament and fiber has been developed as a
synthetic fiber since 1960s. Through such technology, two different
polymers with suitable viscosity, composition are co-extruded
together into one filament through a spinneret from two separate
extenders. The filament's cross-section can be in different pattern
including concentric sheath/core, eccentric sheath/core,
side-by-side, pie wedge, islands/sea mode, which depends on
application requirement. For example, Chinese patent application
under the publication number CN104342802A disclosed a
double-component composite elastic fiber. The fiber disclosed
therein was an extended filament which is formed by parallel
composite spinning of polybutylene terephthalate and polyethylene
glycol terephthalate according to a weight ratio of (70:30)-(30:0),
crimp number of the fiber is 55-75/25 mm, and the crimp radius is
below 1.0 mm. After thermal treatment, the elastic elongation ratio
of the fiber was 80%-120%, and the elastic recovery ratio of the
fiber was above 92%. Another Chinese patent application under the
publication number CN101126180A disclosed a side-by-side
bi-component elastic fiber and its preparation method. In that
Chinese application, by using the shrinkage PET, PBT or PTT, any
two juxtaposed composite polymers could generate spring like
crimping formation with better elasticity after extending heating
treatment, by virtue of the difference in shrinkage properties. PCT
application under the publication number WO 2009099548 A2 described
a method for producing self-crimping fluoropolymer(s) and
perfluoropolymer(s) filaments comprising; heating said
fluoropolymer(s) and/or said perfluoropolymer(s) to a molten state,
extruding said fluoropolymer(s) and/or said perfluoropolymer(s)
under pressure through spinneret plate(s) orifice(s) which create a
filament, as a molten polymer that exhibits differential die swell,
wherein said filament, as a molten polymer expands sectionally and
continuously along a longitudinal length of the resultant filament,
and wherein said spinneret plate orifice(s) comprise a round hole
shape with an ellipsoid peninsula creating an ellipsoid cove gap in
one section of said filament, as a molten polymer and differential
die swell on opposing sides of said ellipsoid cove gap close the
gap creating a seam between said opposing sides such that
differential die swell around said ellipsoid cove gap creates
uneven stresses along one portion of resulting filament thereby
causing said filament to crimp, bend, deform and/or twist toward
said seam in a preferred manner. United States Patent under the
U.S. Pat. No. 4,424,257 disclosed that a self-crimping
multi-component polyamide filament is provided and a process for
producing the filament. In its simplest form, the filament was
composed of two components each of which comprises a polyamide of
the same chemical composition and one of which contains a minor
amount of a polyolefin admixed with the polyamide. The filament was
formed by co-extruding the components to form a conjugate filament
that is attenuated in the molten state, solidified and then
collected. Attenuation of the filament in the molten state imparted
self-crimping properties and molecular orientation to the
filament.
[0006] In view of the disadvantages of the existing SMP, there is a
need for a fiber, filament, or tape that has a stable,
controllable, and tunable crimping shape at different
conditions.
SUMMARY OF THE INVENTION
[0007] Accordingly, a first aspect of the present invention
provides a linear or substantially linear bi-component filament,
fiber, or tape. The filament, fiber, or tape includes a first
elastomeric component having a cross-sectional area of at least
greater than approximately 50 percent of the filament, fiber, or
tape, and having a glass transition temperature of approximately
-125 degrees to -10 degrees Celsius; and a second shape-memory
polymeric component having a cross-sectional area of at least lower
than approximately 50 percent and being selected from one or more
of a thermoplastic polyester-based or polyether-based shape memory
polyurethane, where the polyester-based polyurethane SMP includes a
polycaprolactone-based polymer. The second shape-memory polymeric
component is positioned within the bi-component filament, fiber, or
tape, such that a region of the second shape-memory polymeric
component is asymmetrically disposed with respect to a central core
of the bi-component filament, fiber, or tape. The second
shape-memory polymeric component has a selectively engineered shape
recovery temperature T.sub.r between approximately 25.degree. C.
and 90.degree. C., and the first elastomeric component is more
elastic than that of the second shape-memory polymeric component at
or lower than the selectively engineered shape memory recovery
temperature.
[0008] A second aspect of the present invention is to provide a
linear or substantially linear bi-component filament, fiber, or
tape. The filament, fiber, or tape includes a first elastomeric
component having a cross-sectional area of at least lower than
approximately 50 percent of the filament, fiber, or tape, and
having a glass transition temperature of approximately -125 degrees
to -10 degrees Celsius; a second shape-memory polymeric component
having a cross-sectional area of at least greater than
approximately 50 percent and being selected from one or more of a
thermoplastic polyester-based or polyether-base shape memory
polyurethane, where the polyester-based polyurethane SMP includes a
polycaprolactone-based polymer. The second shape-memory polymeric
component is positioned within the bi-component filament, fiber, or
tape, such that a region of the second shape-memory polymeric
component is asymmetrically disposed with respect to a central core
of the bi-component filament, fiber, or tape. The second
shape-memory polymeric component has a selectively engineered shape
recovery temperature T.sub.r between approximately 25.degree. C.
and 90.degree. C., and the first elastomeric component is more
elastic than that of the second shape-memory polymeric component at
or lower than the selectively engineered shape memory recovery
temperature.
[0009] In one embodiment, the bi-component filament, fiber, or tape
is configured to assume a substantially helical configuration upon
elongation of approximately 50% to approximately 300%, with the
coil number per centimeter increasing with the increase of the
elongation percentage or the time period of elongation.
[0010] In another embodiment, the bi-component filament, fiber, or
tape resumes a substantially linear shape upon heating to the
selectively engineered shape recovery temperature T.sub.r.
[0011] Alternatively, for the first and second aspects of the
present invention, the proportion of the first elastomeric
component and the second shape-memory polymeric component in the
present bi-component filament, fiber, or tape can be defined by
their respective weight ratio. That is, the first elastomeric
component is in a range of 10 to 90 wt. % of the total weight of
the bi-component filament, fiber, or tape while the second
shape-memory polymeric component is in a range of 90 to 10 wt. % of
the total weight of the bi-component filament, fiber, or tape,
wherein the weight ratio between the first elastomeric component
and the second shape-memory polymeric component is 1-9:9-1 so long
as the positioning of the first elastomeric component and the
second shape-memory polymeric component with respect to the
cross-sections along the bi-component filament, fiber, or tape
remains asymmetrical.
[0012] A third aspect of the present invention is to provide a
method of fabricating the present linear or substantially linear
bi-component filament, fiber, or tape comprising any polymeric
fiber forming techniques such as wet, dry, gel, electro-, drawing
spinning, either by single or multiple extrusion. Detail of the
fabrication method is described herein after by embodiments or
examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Embodiments of the present invention are described in more
detail hereinafter with reference to the drawings, in which:
[0014] FIGS. 1A to 1C illustrate different embodiments of the
present invention in terms of different arrangement of the
elastomer and the shape-memory polymer (SMP) from the
cross-sectional view in order to result in different
three-dimensional structure of the present invention:
[0015] FIG. 1A illustrates an asymmetrical side-by-side arrangement
of the elastomer and SMP according to an embodiment of the present
invention; FIG. 1B illustrates an asymmetrical eccentric
arrangement of the elastomer and SMP according to an embodiment of
the present invention; FIG. 1C illustrates an asymmetrical and
nearly rectangular arrangement of elastomer and SMP according to an
embodiment of the present invention;
[0016] FIGS. 2A to 2D illustrate from cross-sectional view the
structure of the bi-component filament or fiber according to
various embodiments of the present invention: FIG. 2A illustrates a
cross-section of the bi-component filament or fiber with an
elastomer to SMP ratio of about 2:1; FIG. 2B illustrates a
cross-section of the bi-component filament or fiber with an
elastomer to SMP ratio of about 3:1; FIG. 2C illustrates a
cross-section of the bi-component filament or fiber with an
elastomer to SMP ratio of about 3:2; FIG. 2D illustrates a
cross-section of the bi-component filament or fiber with an
elastomer to SMP ratio of about 2:1; FIG. 2E illustrates a
cross-section of the bi-component filament or fiber with an
elastomer to shape memory polymer (SMP) ratio of about 3:1;
[0017] FIG. 3 are images showing procedures of "stretching" and
"releasing" the bi-component filament, fiber, or tape according to
an embodiment of the present invention;
[0018] FIG. 4A illustrates that the coil diameter of examples 2 to
4 decreases with the increase of the elongation percentage, and the
coil number per cm increases approximately with the increase of the
elongation percentage;
[0019] FIG. 4B illustrates that the coil diameter of examples 5 to
7 decreases with the increase of the elongation percentage, and the
coil number per cm increases with the increase of the elongation
percentage;
[0020] FIG. 5A is an image showing an example of the bi-component
filament with estimated measurements of coil diameter and pitch
distance;
[0021] FIG. 5B is an image showing another example of the
bi-component filament with estimated measurements of filament
diameter, coil diameter, and pitch distance.
DEFINITIONS
[0022] The term "linear" used herein to describe a state of the
present bi-component filament, fiber, or tape refers to a closely
or substantially linear state of an as-formed bi-component
filament, fiber or tape of the present invention which can be
observed visually or determined qualitatively and/or
quantitatively. In other words, the phrase "linear or substantially
linear bi-component filament, fiber, or tape" or alike used herein
could refer to an as-formed bi-component filament, fiber, or tape
which is either or both qualitatively and quantitatively determined
that it is arranged in or extending along a straight or nearly
straight line.
[0023] The terms "filament" and "fiber" used herein, and sometimes
they are used herein interchangeably, refer to a three-dimensional
structure with an elongated morphology. In some contexts, the term
"filament" or "fiber" can also refer to a slender threadlike object
or article.
[0024] The term "elastomer" or "elastomeric component" used herein,
or sometimes they are used interchangeably, refers to a material
which exhibits the property of elasticity, low Young's modulus
(i.e. the ratio of tensile stress to tensile strain) and with the
ability to deform when a stress is applied and resume to its
original form (i.e., length, volume, shape, etc.) when the stress
is removed. Examples of elastomers used in the present invention
include, but are not limited to polyester or polyether-based
polyurethanes.
[0025] The term "shape memory polymer" or "shape-memory polymeric
component" used herein, or sometimes they are used interchangeably,
refers to a unique class of polymers or materials which exhibit the
ability to fix a temporary shape and then resume to a prior state
by an external stimulus (e.g. heat, radiation, solvent, electrical
current, light, magnetic fields, or a change in pH). Examples of
shape memory polymers used in the present invention include, but
are not limited to polyester-based or polyether-based shape memory
polyurethane, where polyester-based SMP includes but not limited to
polycaprolactone-based SMP.
DETAILED DESCRIPTION
[0026] The present invention is not to be limited in scope by any
of the following descriptions. The following examples or
embodiments are presented for exemplification only.
[0027] Turning now to the drawings in detail, FIGS. 1A to 1C
schematically depicts examples of configurations for linear
bi-component filaments, fibers, or tapes of the present invention.
The linear bi-component filaments, fibers, or tapes include
elastomeric and shape memory polymer portions such that the
filaments undergo deformation-based (stretching-induced) crimping,
assuming a substantially helical configuration following elongation
on the order of approximately 50 percent to approximately 300
percent. Upon heating to a temperature greater than a recover
temperature, the materials resume the permanent, approximately
linear configuration.
[0028] FIG. 1A and FIG. 1B show a cross-section of filament or
fibers 100 while FIG. 1C shows a cross-section of a tape 200. In
each of these arrangements, the shape memory polymeric region is
indicated by reference numeral 10 and the elastomeric component is
indicated by reference numeral 20.
[0029] As seen in FIGS. 1A-1C, a variety of configurations can be
used in the bi-component filaments of the present invention. For
example, in FIG. 1A, the shape memory polymer 10 is formed in a
region offset from the core of the fiber or filament; similarly, in
FIG. 1B, the shape memory polymer 10 is also offset from a central
core region of the tape. That is, the shape memory polymer region
10 is always asymmetrically-positioned with respect to a center of
the cross-sectional area of a filament, fiber, or tape. In these
examples, a bi-component filament can be made of thermoplastic
polyurethane elastomer (TPU) and SMP with a weight ratio from
90%:10% to 10%:90%. The cross-section can be either side-by-side
(FIG. 1A) or eccentric sheath/core (FIG. 1B). For the present
bi-component tape (e.g., FIG. 1C), it can also be made of
thermoplastic polyurethane elastomer (TPU) and SMP with a weight
ratio from 90%:10% to 10%:90%.
[0030] FIGS. 2A to 2E show some examples of asymmetrically
arranging or positioning the elastomer and SMP from the
cross-sectional view to form the bi-component filament or fiber. In
those examples, each of the elastomer fiber(s) and SMP fiber(s) are
longitudinally aligned with each other according to an unequal
number of fibers between two different polymeric fibers, e.g., 2:1,
3:1, 4:1, 1:2, 1:3, 1:4, etc. In other words, the ratio of the
elastomer fiber to shape memory polymer fiber is x:y or y:x, where
x is smaller or larger than y by at least 1 in those examples. It
should be understood that in terms of weight ratio, the ratio
between elastomer fibers and shape memory polymer fibers does not
have to be integers. The prerequisite to form the present
bi-component filament, fiber, or tape is to position or arrange the
elastomer and SMP asymmetrically with respect to the cross-sections
along the bi-component filament, fiber, or tape such that the
present bi-component filament, fiber, or tape is in linear or
substantially linear state or shape when there is no corresponding
external stimulus while it curls and forms corresponding number of
coils upon stretching or elongation from about 50% up to about 300%
of its original length and for a period of time, and it is capable
of resuming its linear or substantially linear state or shape upon
heating up to about its shape recovery temperature of about 25 to
90.degree. C.
[0031] The present invention related to the manufacture and process
for the production of filaments, fibers, tapes with "stretching
induced crimping and heat-induced uncurling" function, which are
made from co-extruded SMP and elastomer. Such smart function is
arising from the bi-component filament structure, in which
elastomer part keeps good elasticity at various temperature from
room temperature to 90 degree Celsius, and SMP provides
pseudo-plasticity at temperature lower than T.sub.r, and elasticity
at temperature above T.sub.r. Therefore, after stretching and
releasing at room temperature (lower than T.sub.r),
pseudo-plasticity in SMP side has trended to keep elongation, and
at the same time, elasticity in elastomer side shrinks more or
less. Therefore, self-crimping is made. Subsequently, if the
crimped filament, fiber or tape is heated up to above T.sub.r,
pseudo-plasticity of SMP will be removed and turn to be elastic,
which push the crimping shape being straightened instantly.
[0032] As shown in FIG. 3, through stretching to a certain value,
such as 50% to 300%, at room temperature and releasing it to free
standing status (301), the present bi-component filament instantly
forms crimping shape from the substantially linear shape.
Subsequently, for the crimping shape, the uncurling process is
easily realized through heating the filament above shape recovery
temperature of SMP (302). In the present invention, the shape
recovery temperature of SMP used is above room temperature, such as
from 25 to 90 degree Celsius.
[0033] To carry out bi-component filament extrusion, the spinneret
with side-by-side or eccentric sheath/core two component structure
is used. TPU with excellent elasticity would be a suitable
candidate such as Elastollan.RTM. C80A10, C85A10, Estane.RTM.
S385A. SMP can include T.sub.g (glass transition as trigger
temperature) type such as Diaplex 2520, 3520, 4520 or T.sub.m
(melting point as trigger temperature) type such as
polycaprolactone based SMP as reported in a literature by Zhu, Y.,
Hu, J., & Yeung, K. (2009) ("Effect of soft segment
crystallization and hard segment physical crosslink on shape memory
function in antibacterial segmented polyurethane ionomers", Acta
Biomaterialia, 5(9), 3346), which is incorporated herein by
reference in its entirety. Due to the crimping caused by
stretching, stretch-ability and thermal plasticity are
prerequisites.
[0034] The following examples accompanied will illustrate the
present invention in more detail:
[0035] Estane.RTM. S385A is chosen in elastomer part. Hardness is
85A. Ultimate elongation is 780%. Polycaprolactone diol (Mn=10000)
based SMP with MDI (4,4'-Methylenebis(phenylisocyanate)), BDO
(1,4-Butanediol), or N,N-bis(2-hydroxyethyl)-isonicotinamide (BIN)
in hard segments is used in SMP part as reported in literature
(Zhu, Y., Hu, J., & Yeung, K. (2009), "Effect of soft segment
crystallization and hard segment physical crosslink on shape memory
function in antibacterial segmented polyurethane ionomers", Acta
Biomaterialia, 5(9), 3346). T.sub.r of SMP used is 48 degree
Celsius or SMP part can be Diaplex MM4520 with Tg of 45 degree
Celsius.
TABLE-US-00001 TABLE 1 Physical properties of example 1 to example
7. Elastomer:SMP Diameter Coil Shape Weight (Filament) or
Elongation Coil Number recovery Example Shape Elastomer SMP Ratio
thickness (tape) % Diameter Per cm temperature 1 Filament Estane
.RTM.S385A *Polycaprolactone 7:3 1.2 mm 100 3 mm 9 48.degree. C.
based SMP-1 2 Filament Estane .RTM.S385A **SMP-2 8:2 1.2 mm 100 5
mm 10 45.degree. C. 3 Filament Estane .RTM.S385A **SMP-2 8:2 1.2 mm
150 4 mm 11 45.degree. C. 4 Filament Estane .RTM.S385A **SMP-2 8:2
1.2 mm 200 3 mm 12 45.degree. C. 5 Tape Estane .RTM.S385A
***Polycaprolactone 6:4 0.7 mm 100 7 mm 7 43.degree. C. based SMP-3
6 Tape Estane .RTM.S385A ***Polycaprolactone 6:4 0.7 mm 200 5 mm 9
43.degree. C. based SMP-3 7 Tape Estane .RTM.S385A
***Polycaprolactone 6:4 0.7 mm 300 3 mm 13 43.degree. C. based
SMP-3 8 Tape Estane .RTM.S385A ***Polycaprolactone 7:3 0.9 mm 100 3
mm 13 80.degree. C. based SMP-3 9 Filament Estane .RTM.S385A
.sup.#SMP-4 55:45 0.100 mm 100 0.508 mm 32 40.degree. C. 10
Filament Estane .RTM.S385A .sup.##Poly(hexylene 55:45 0.105 mm 100
0.509 mm 28 40.degree. C. adipate) based SMP-5 Keys:-
*Polycaprolactone based SMP-1 is from: Zhu, Y., Hu, J., &
Yeung, K., "Effect of soft segment crystallization and hard segment
physical crosslink on shape memory function in antibacterial
segmented polyurethane ionomers", Acta Biomaterialia, 2009, 5(9),
3346; **SMP-2 is Diaplex .TM. shape memory polymer 4520;
***Polycaprolactone based SMP-3 is from: Zhu Y, Hu J, Choi K F, et
al. Crystallization and melting behavior of the crystalline soft
segment in a shape-memory polyurethane ionomer[J], Journal of
Applied Polymer Science, 2008, 107(1): 599-609; .sup.#SMP-4 is a
blend of two SMPs by using Diaplex .TM. shape memory polymer 4520
and 3520 with the weight ratio of 50/50; .sup.##SMP-5 is from: Chen
S., Hu J., Liu Y., et al. Effect of SSL and HSC on morphology and
properties of PHA based SMPU synthesized by bulk polymerization
method[J]. Journal of Polymer Science Part B: Polymer Physics,
2007, 45, 444
Example 1
[0036] For bi-component filament with 1.2 mm diameter, elastomer
Estane.RTM. S385A and polycaprolactone based SMP are coextruded
with weight ratio 7:3 (melt flow pump control) by using
side-by-side nozzle. Prior to processing, all pellets must be dried
at 104 degree Celsius for 2-4 hours. The barrel temperature of
extruder would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The filament is cooling through
cold water with a temperature of about 15 degree Celsius from
nozzle without any stretching process. The bi-component filament
prepared can show the "smart coil" function, in which stretching to
100% elongation ratio can give rise to crimping shape with 3 mm of
coil diameter, 9 turns per cm and heating up to about 48-80 degree
Celsius leads to straight shape back.
Example 2
[0037] For bi-component filament with 1.2 mm diameter, elastomer
Estane.RTM. S385A and Diaplex MM4520 SMP are coextruded with a
weight ratio of 8:2 (melt flow pump control) by using eccentric
nozzle. Prior to processing, all pellets must be dried at 104
degree Celsius for 2-4 hours. The barrel temperature of extruder
would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The filament is cooling through
cold water with a temperature of about 15 degree Celsius from
nozzle without any stretching process. The bi-component filament
prepared can show the "smart coil" function, in which stretching to
100% elongation ratio can give rise to crimping shape with 5 mm of
coil diameter, 10 turns per cm and heating up to about 45-50 degree
Celsius leads to straight shape back.
Example 3
[0038] For bi-component filament with 1.2 mm diameter, elastomer
Estane.RTM. S385A and Diaplex MM4520 SMP are coextruded with a
weight ratio of 8:2 (melt flow pump control) by using eccentric
nozzle. Prior to processing, all pellets must be dried at 104
degree Celsius for 2-4 hours. The barrel temperature of extruder
would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The filament is cooling through
cold water with a temperature of about 15 degree Celsius from
nozzle without any stretching process. The bi-component filament
prepared can show the "smart coil" function, in which stretching to
150% elongation ratio can give rise to crimping shape with 4 mm of
coil diameter, 11 turns per cm and heating up to about 45 degree
Celsius leads to straight shape back.
Example 4
[0039] For bi-component filament with 1.2 mm diameter, elastomer
Estane.RTM. S385A and Diaplex MM4520 SMP are coextruded with a
weight ratio of 8:2 (melt flow pump control) by using eccentric
nozzle. Prior to processing, all pellets must be dried at 104
degree Celsius for 2-4 hours. The barrel temperature of extruder
would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The filament is cooling through
cold water with a temperature of about 15 degree Celsius from
nozzle without any stretching process. The bi-component filament
prepared can show the "smart coil" function, in which stretching to
200% elongation ratio can give rise to crimping shape with 3 mm of
coil diameter, 12 turns per cm and heating up to about 45-60 degree
Celsius leads to straight shape back.
[0040] The coil diameter and coil number per cm were measured for
bi-component filament with 1.2 mm diameter, elastomer Estane.RTM.
S385A and polyurethane based SMP being coextruded with a weight
ratio of 8:2 (melt flow pump control) by using eccentric nozzle
(FIG. 4A). With the elongation percentage from 100% to 200%, the
coil diameter is decreasing from 5 mm to 3 mm, and the coil number
per cm is increasing from 10 to 12.
Example 5
[0041] For bi-component tape with 0.7-mm thickness, elastomer
Estane.RTM. S385A and polycaprolactone based SMP are coextruded
with weight ratio 6:4 (melt flow pump control) by using layer by
layer slot die. Prior to processing, all pellets must be dried at
104 degree Celsius for 2-4 hours. The barrel temperature of
extruder would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The tape is cooling through cold
water with a temperature of about 15 degree Celsius from nozzle
without any stretching process. The bi-component tape prepared can
show the "smart coil" function, in which stretching to 100%
elongation ratio can give rise to crimping shape with 7 mm of coil
diameter, 7 turns per cm, and heating up to about 43 degree Celsius
leads to straight shape back.
Example 6
[0042] For bi-component tape with 0.7-mm thickness, elastomer
Estane.RTM. S385A and polycaprolactone based SMP are coextruded
with weight ratio 6:4 (melt flow pump control) by using layer by
layer slot die. Prior to processing, all pellets must be dried at
104 degree Celsius for 2-4 hours. The barrel temperature of
extruder would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The tape is cooling through cold
water with a temperature of about 15 degree Celsius from nozzle
without any stretching process. The bi-component tape prepared can
show the "smart coil" function, in which stretching to 200%
elongation ratio can give rise to crimping shape with 5 mm of coil
diameter, 9 turns per cm, and heating up to about 43 degree Celsius
leads to straight shape back.
Example 7
[0043] For bi-component tape with 0.7-mm thickness, elastomer
Estane.RTM. S385A and polycaprolactone based SMP are coextruded
with weight ratio 6:4 (melt flow pump control) by using layer by
layer slot die. Prior to processing, all pellets must be dried at
104 degree Celsius for 2-4 hours. The barrel temperature of
extruder would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The tape is cooling through cold
water with a temperature of about 15 degree Celsius from nozzle
without any stretching process. The bi-component tape prepared can
show the "smart coil" function, in which stretching to 300%
elongation ratio can give rise to crimping shape with 3 mm of coil
diameter, 13 turns per cm, and heating up to about 43 degree
Celsius leads to straight shape back.
[0044] The coil diameter and coil number per cm were measured for
bi-component tape with 0.7 mm thickness, elastomer Estane.RTM.
S385A and polycaprolactone based SMP being coextruded with a weight
ratio of 6:4 (melt flow pump control) by using layer by layer slot
die (FIG. 4B). With the elongation percentage from 100% to 200%,
the coil diameter is decreasing from 7 mm to 3 mm, and the coil
number per cm is increasing from 7 to 13.
Example 8
[0045] For bi-component tape with 0.9-mm thickness, elastomer
Estane.RTM. S385A and polycaprolactone based SMP are coextruded
with weight ratio 7:3 (melt flow pump control) by using layer by
layer slot die. Prior to processing, all pellets must be dried at
104 degree Celsius for 2-4 hours. The barrel temperature of
extruder would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The tape is cooling through cold
water with a temperature of about 15 degree Celsius from nozzle
without any stretching process. The bi-component tape prepared can
show the "smart coil" function, in which stretching to 100%
elongation ratio can give rise to crimping shape with 3 mm of coil
diameter, 13 turns per cm and heating up to about 40-80 degree
Celsius leads to straight shape back.
Example 9
[0046] For bi-component filament with 0.1 mm diameter, elastomer
Estane.RTM. S385A and blended two SMPs of Diaplex.TM. shape memory
polymer 4520 and 3520 with the weight ratio of 50/50 are coextruded
with weight ratio 55:45 (melt flow pump control) by using
side-by-side nozzle. Prior to processing, all pellets must be dried
at 104 degree Celsius for 2-4 hours. The barrel temperature of
extruder would be 180.about.195 (zone 1), 185.about.200 (zone 2),
190.about.205 (zone 3), 190.about.200 (Die zone) degree Celsius.
Screw speed is 180.about.200 rpm. The filament is cooling through
cold water with a temperature of about 15 degree Celsius from
nozzle without any stretching process. The bi-component filament
prepared can show the "smart coil" function, in which stretching to
100% elongation ratio can give rise to crimping shape with 0.508 mm
of coil diameter, 32 turns per cm and heating up to about 40 degree
Celsius leads to straight shape back.
Example 10
[0047] For bi-component filament with 0.105 mm diameter, elastomer
Estane.RTM. S385A and Poly(hexylene adipate) based SMP are
coextruded with weight ratio 55:45 (melt flow pump control) by
using side-by-side nozzle. Prior to processing, all pellets must be
dried at 104 degree Celsius for 2-4 hours. The barrel temperature
of extruder would be 180.about.195 (zone 1), 185.about.200 (zone
2), 190.about.205 (zone 3), 190.about.200 (Die zone) degree
Celsius. Screw speed is 180.about.200 rpm. The filament is cooling
through cold water with a temperature of about 15 degree Celsius
from nozzle without any stretching process. The bi-component
filament prepared can show the "smart coil" function, in which
stretching to 100% elongation ratio can give rise to crimping shape
with 0.508 mm of coil diameter, 28 turns per cm and heating up to
about 40 degree Celsius leads to straight shape back.
[0048] It should be apparent to those skilled in the art that many
modifications besides those already described are possible without
departing from the inventive concepts herein. The inventive subject
matter, therefore, is not to be restricted except in the spirit of
the disclosure. Moreover, in interpreting the disclosure, all terms
should be interpreted in the broadest possible manner consistent
with the context. In particular, the terms "includes", "including",
"comprises" and "comprising" should be interpreted as referring to
elements, components, or steps in a non-exclusive manner,
indicating that the referenced elements, components, or steps may
be present, or utilized, or combined with other elements,
components, or steps that are not expressly referenced.
* * * * *