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 Tr between approximately 25° C. and 90° C.

Description

FIELD OF THE INVENTION

The present invention relates to a substantially linear bi-component filament, fiber, or tape, and method of using thereof.

BACKGROUND

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.

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_g) or melting temperature (T_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.

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.

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

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_r between approximately 25° C. and 90° 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.

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_r between approximately 25° C. and 90° 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.

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.

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_r.

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.

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

Embodiments of the present invention are described in more detail hereinafter with reference to the drawings, in which:

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:

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;

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;

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;

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;

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;

FIG. 5A is an image showing an example of the bi-component filament with estimated measurements of coil diameter and pitch distance;

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

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.

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.

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.

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

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.

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.

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.

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%.

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° C.

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_r, and elasticity at temperature above T_r. Therefore, after stretching and releasing at room temperature (lower than T_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_r, pseudo-plasticity of SMP will be removed and turn to be elastic, which push the crimping shape being straightened instantly.

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.

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® C80A10, C85A10, Estane® S385A. SMP can include T_g (glass transition as trigger temperature) type such as Diaplex 2520, 3520, 4520 or T_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.

The following examples accompanied will illustrate the present invention in more detail:

Estane® 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_r of SMP used is 48 degree Celsius or SMP part can be Diaplex MM4520 with Tg of 45 degree Celsius.

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 ®S385A	*Polycaprolactone	7:3	1.2	mm	100	3	mm	9	48° C.
			based SMP-1
2	Filament	Estane ®S385A	**SMP-2	8:2	1.2	mm	100	5	mm	10	45° C.
3	Filament	Estane ®S385A	**SMP-2	8:2	1.2	mm	150	4	mm	11	45° C.
4	Filament	Estane ®S385A	**SMP-2	8:2	1.2	mm	200	3	mm	12	45° C.
5	Tape	Estane ®S385A	***Polycaprolactone	6:4	0.7	mm	100	7	mm	7	43° C.
			based SMP-3
6	Tape	Estane ®S385A	***Polycaprolactone	6:4	0.7	mm	200	5	mm	9	43° C.
			based SMP-3
7	Tape	Estane ®S385A	***Polycaprolactone	6:4	0.7	mm	300	3	mm	13	43° C.
			based SMP-3
8	Tape	Estane ®S385A	***Polycaprolactone	7:3	0.9	mm	100	3	mm	13	80° C.
			based SMP-3
9	Filament	Estane ®S385A	#SMP-4	55:45	0.100	mm	100	0.508	mm	32	40° C.
10	Filament	Estane ®S385A	##Poly(hexylene	55:45	0.105	mm	100	0.509	mm	28	40° 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 ™ 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;
#SMP-4 is a blend of two SMPs by using Diaplex ™ shape memory polymer 4520 and 3520 with the weight ratio of 50/50;
##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

For bi-component filament with 1.2 mm diameter, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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

For bi-component filament with 1.2 mm diameter, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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

For bi-component filament with 1.2 mm diameter, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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

For bi-component filament with 1.2 mm diameter, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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.

The coil diameter and coil number per cm were measured for bi-component filament with 1.2 mm diameter, elastomer Estane® 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

For bi-component tape with 0.7-mm thickness, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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

For bi-component tape with 0.7-mm thickness, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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

For bi-component tape with 0.7-mm thickness, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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.

The coil diameter and coil number per cm were measured for bi-component tape with 0.7 mm thickness, elastomer Estane® 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

For bi-component tape with 0.9-mm thickness, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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

For bi-component filament with 0.1 mm diameter, elastomer Estane® S385A and blended two SMPs of Diaplex™ 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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

For bi-component filament with 0.105 mm diameter, elastomer Estane® 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˜195 (zone 1), 185˜200 (zone 2), 190˜205 (zone 3), 190˜200 (Die zone) degree Celsius. Screw speed is 180˜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.

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.

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, andwherein the shape memory polymer has a selectively engineered shape recovery temperature Tr between approximately 25° C. and 90° 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, andwherein the shape memory polymer has a selectively engineered shape recovery temperature Tr between approximately 25° C. and 90° 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 Tr.

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 Tr.

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.