Abstract
The production of bicomponent polymer fibers may be enhanced to provide greater bulk in bulk continuous filaments by creating differential stresses in the extruded combined melt and using those differential stresses to increase crimps, twists, and rotations thereby providing greater bulk. In one of many possible embodiments, these differential stresses may be formed by combining polymer compositions having different properties, or during the extrusion of the combined polymer melt from the spinneret, or by environmentally treating the melt spun bicomponent filament. The inventions disclosed and taught herein may be applied to the production of all types of bicomponent polymer fibers including, and without limitation, side-by-side and core and sheath extrusions.
Claims
1.-162. (canceled)
163. A bulked continuous bicomponent filament comprising: a first polymer composition and a second polymer composition, wherein the polymer compositions have at least one rheological property, wherein the at least one rheological property of the first polymer composition is different from the at least one rheological property of the second polymer composition.
164. The bulked continuous bicomponent filament of claim 163, wherein the first polymer composition and the second polymer composition comprise the same polymer.
165. The bulked continuous bicomponent filament of claim 164, wherein the at least one rheological property is due to an additive selected from the group consisting of an intrinsic viscosity, a flow aid, a molecular weight booster, a melt flow manipulating agent, a colorant, a plasticizer, or a nucleating agent.
166. The bulked continuous bicomponent filament of claim 165, wherein the first and second polymer compositions have a different melt viscosity.
167. The bulked continuous bicomponent filament of claim 166, wherein the first and second polymer compositions comprise a homopolymer.
168. The bulked continuous bicomponent filament of claim 167, wherein the first and second polymer compositions comprise a copolymer.
169. A method of manufacturing the bulked continuous bicomponent filament of claim 168, comprising: selecting the at least one property of the first and second polymer compositions such that the rheology of the combined polymer melts produces a differential stress between the first and second polymer compositions; and combining the first and second polymer compositions and extruding the combination from a spinneret into a melt spun bicomponent filament.
170. The method of manufacturing the bulked continuous bicomponent filament of claim 169, further comprising: selecting a second property of the first and second polymer compositions such that the rheology of the combined polymer melts produces a second differential stress between the first and second polymer compositions.
171. The method of manufacturing the bulked continuous bicomponent filament of claim 170, further comprising configuring a distance from the spinneret to a godet.
172. The method of manufacturing the bulked continuous bicomponent filament of claim 171, further comprising the addition or removal of a draw point localizer that changes the stress on the filament as it leaves the spinneret.
173. The method of manufacturing the bulked continuous bicomponent filament of claim 172, wherein the method is performed with one environmental condition selected from the group of varying temperature, varying humidity, or combinations thereof.
174. The method of manufacturing the bulked continuous bicomponent filament of claim 173, wherein cooling and/or quenching the bulked continuous bicomponent filament is performed with a process consisting of one of varying the stack height, varying the stack draw, varying the mechanical draw, or combinations thereof.
175. A method of manufacturing a plurality of bulked continuous filaments, comprising: providing a polymer melt; separating the polymer melt into a first portion and a second portion; treating the first portion to have a different rheological property than the second portion; combining the first and second portions; and melt spinning the combined portions into the plurality of bulked continuous filaments; wherein treating the first portion to have a different rheological property comprises adding an additive chosen from the group consisting of a flow aid, a molecular weight booster, a melt flow manipulating agent, a colorant, a plasticizer, a nucleating agent, or combinations thereof.
176. The method of claim 175, wherein the treated first portion and the second portion have different molecular weights.
177. The method of claim 176, wherein the second portion is treated with an additive chosen from the group consisting of a flow aid, a molecular weight booster, an intrinsic viscosity enhancer, a melt flow manipulating agent, a colorant, a plasticizer, a nucleating agent, or combinations thereof.
178. The method of claim 177, wherein melt spinning comprises extruding the combined first and second portions from a plurality of capillaries and wherein the combined first and second portions are distributed non-symmetrically along a cross-section of the plurality of capillaries.
179. The method of claim 178, wherein the combined first and second portions are distributed along the cross-section of the plurality of capillaries configured to extrude a core and a sheath filament, wherein the core comprises the first portion and the sheath comprises the second portion.
180. The method of claim 178, wherein the combined first and second portions are distributed along the cross-section of the plurality of capillaries configured to extrude a trilobal filaments, wherein a first lobe of each of the trilobal filaments comprises the first portion, and wherein a second and a third lobe of each of the trilobal filaments comprises the second portion.
181. The method of claim 178, wherein the plurality of bulked continuous filaments is quenched by cooling the filaments with a fluid of varying temperature, varying humidity, or combinations thereof.
182. A plurality of bulked continuous filaments, comprising: a first polymer composition comprising a first additive and having a first and a second rheological properties and a second polymer composition comprising a second additive and having the first and the second rheological properties; wherein the first rheological property of the first polymer composition is different from the first rheological property of the second polymer composition; and wherein the second rheological property of the first polymer composition is different from the second rheological property of the second polymer composition; wherein the first additive is selected from the group consisting of a flow aid, a molecular weight booster, a melt flow manipulating agent, a colorant, a plasticizer, a nucleating agent, or combinations thereof; wherein the second additive is selected from the group consisting of a flow aid, a molecular weight booster, an intrinsic viscosity enhancer, a melt flow manipulating agent, a colorant, a plasticizer, a nucleating agent, or combinations thereof; and wherein the first rheological property is not the same as the second rheological property.
Description
DESCRIPTION
[0042] With the intention of better showing the characteristics of the invention, herein after, as an example without any limitative character, some preferred embodiments are described, with reference to the accompanying drawings, wherein:
[0043] FIG. 1 illustrates a schematic diagram of a system according to one implementation disclosed and taught herein;
[0044] FIG. 2 illustrates a schematic diagram of an alternative embodiment system according to one implementation disclosed and taught herein;
[0045] FIG. 3 illustrates a schematic diagram of optional post-spinning processes for the system shown in FIG. 1;
[0046] FIG. 4 illustrates a perspective view of an elongated multi-component filament according to one embodiment;
[0047] FIG. 5 illustrates a perspective view of an elongated multi-component filament according to another embodiment;
[0048] FIG. 6 illustrates a radial cross-sectional view of a filament according to another embodiment;
[0049] FIG. 7 illustrates a radial cross-sectional view of a filament according to one embodiment;
[0050] FIG. 8 illustrates a radial cross-sectional view of a filament according to one embodiment.
[0051] FIG. 9 illustrates a radial cross-sectional view of a filament according to another embodiment.
[0052] FIG. 10 illustrates a radial cross-sectional view of a filament according to another embodiment.
[0053] FIG. 11 illustrates a radial cross-sectional view of a filament according to one embodiment.
[0054] FIG. 12 illustrates a radial cross-sectional view of a filament according to another embodiment.
[0055] FIG. 13 illustrates a radial cross-sectional view of a filament according to another embodiment.
[0056] FIG. 14 illustrates a radial cross-sectional view of a filament according to another embodiment.
[0057] FIG. 15 illustrates a radial cross-sectional view of a filament according to another embodiment.
[0058] FIG. 16 illustrates a radial cross-sectional view of a filament according to another embodiment.
[0059] In the way of example and without limitation, FIG. 1 illustrates a schematic diagram of a system according to one implementation. The system 100 includes an extruder 102, and a spin station 106. The spin station 106 includes a spinneret 108, and a manifold plate 105 through which a polymer composition may flow to the spinneret 108. The system 100 also includes an injector 104. In a first leg 110, the extruder may inject the polymer composition from the extruder 102 directly to the spin station. In a second leg 111, the extruder may flow the same polymer composition towards the spin station 106, but an IV enhancer may be added from a separate container 103 through tube 113 into the injector 104, where the mixture then flows into the spin station 106 through tube 112. The mixture of the polymer composition and the IV enhancer may now be considered to be a second polymer composition, where the untreated polymer composition traveling through tube 110 may be considered to be the first polymer composition.
[0060] Those of ordinary skill in the art will note that to illustrate the inventions taught and disclosed herein, some components, such as pumps and monitoring equipment, have been left out of this illustrative schematic for clarity.
[0061] Within the spin station 106, the polymer compositions may be rejoined to form a plurality, or bundle of extruded filaments 114 with at least one differential stress. For example, and without limitation, the resulting filaments 114 may be a trilobal filament with the core comprising the first polymer composition; two of the lobes also comprising the first polymer composition; and the third lobe comprising the second polymer composition that contains the IV enhancer.
[0062] Similarly, FIG. 2 illustrates a schematic diagram of a system according to a second implementation. The system 200 includes a first extruder 201, a second extruder 202, and a spin station 206. The spin station 206 includes a spinneret 208, and a manifold plate 205 through which the two polymer compositions may flow to the spinneret 208. The system 200 also includes an injector 204. In a first leg 210, the extruder may inject the first polymer composition from the extruder 201 directly to the spin station. In a second leg 211, the extruder may flow a second polymer composition towards the spin station 206, but an optional IV enhancer may be added from a separate container 203 through tube 213 into the injector 204, where the mixture then flows into the spin station 206 through tube 212.
[0063] Those of ordinary skill in the art will understand that the spin stations illustrated in FIGS. 1 and 2 may comprise additional features that are not depicted in these exemplary illustrations. Without limit, these additional features may include a breaker plate, a spin pump, and/or sensors and monitors such as pressure and temperature sensors.
[0064] Within the spin station 206, the polymer compositions may be rejoined to form a plurality, or bundle of extruded filaments 214 with at least one differential stress. For example, and without limitation, the resulting filaments 214 may be a trilobal filament with the core comprising the first polymer composition; two of the lobes also comprising the first polymer composition; and the third lobe comprising the second polymer composition that contains the optional IV enhancer. In another embodiment, the optional IV enhancer may not be mixed with the second polymer composition, however, the extruded filaments 214 would still have at least one exploitable differential stress.
[0065] As noted throughout this specification, rather than an IV enhancer being injected into the second polymer composition, other additive may be mixed, such as but not limited to a flow aid, a molecular weight booster, a melt flow manipulating agent, a colorant, a plasticizer, a nucleating agent, or combinations thereof.
[0066] FIG. 3 illustrates a schematic diagram of optional post-spinning processes for a portion of the bundle of filaments 314. These were illustrated as bundles of filaments 114 or 214 from the spinning system in FIG. 1 or 2. These optional post-spinning processes may further contribute to developing twists and/or crimps or may be used to exploit any differential stresses in the filaments 314. FIG. 3 illustrates some of these processes with respect to the bundles of filaments 314. The processes include (1) tacking spun filaments in at least one bundle separately from other bundles after spinning and prior to or during the drawing process, (2) texturing tacked spun filaments in at least one bundle separately from the other bundles after the drawing process, and (3) tacking textured and tacked spun filaments in at least one bundle separately from the other bundles and feeding the bundles to a mixing cam that feeds the bundles to a final tacking device for tacking together the bundles into a yarn.
[0067] As shown in FIG. 3, each bundle of spun filaments 314 are tacked by a tacking device 325. The tacking may be done with air entangling or other means known to those skilled in the art. In addition, the tacking device 325 may use pressure, with the pressure varying with an increased number of filaments, increased denier per filament, and/or increased speed of filament production.
[0068] As may be known to those of skill in the art and in possession of the teachings and inventions within this disclosure, tacking may induce yet another exploitable stress within filaments. Tacking may be combined with other means for inducing exploitable stresses disclosed herein to contribute to producing desirable crimps, twists, and rotations.
[0069] The exemplary tacking device 325 may be air entanglers that use room temperature air for entangling the filaments. In other embodiments, the tacking devices may include heated air entanglers (e.g., air temperature is higher than room temperature) or steam entanglers, for example that may exploit any differential stresses in the filaments 314.
[0070] The bundles of tacked filaments 326 may be drawn to a final titer by drawing device 360, which may be a plurality of godets. The godets may each be turned at a different speed, according to some embodiments.
[0071] In alternative embodiments (not shown in FIG. 3), exploiting a differential stress may be performed by turning air streams off or on to the exemplary tacking device 325. Similarly, variable air streams may be used. In addition, in other embodiments, air or other fluids may be applied constantly or in an on/off sequence to get the desired end effect.
[0072] And, in yet another embodiment (not shown in FIG. 3), the bundles of spun filaments may be first elongated partially before being tacked individually. This may cause exploitable stresses between the fibers as disclosed and taught herein. After the tacking step, the spun, tacked bundles may be further elongated to the final denier.
[0073] The bundles 314 may be texturized separately through a texturizer 372. Following this step, a bundle 328 of texturized filaments are provided.
[0074] The texturizer 372 may apply air, steam, heat, mechanical force, or a combination of one of more of the above to the filaments to cause the filaments to bulk (or crimp/shrink) from their exploitable stresses.
[0075] Next, the texturized filaments 328 may be provided to an individual color entanglement process prior to the final tacking at tacking device 380.
[0076] The tacking device 329 may be air entanglers that use room temperature air applied at a pressure, for example, for entangling the filaments. But the pressure may be varied with an increased number of filaments, increased denier per filament, and/or increased the speed of filament production. And, in other embodiments, the tacking device 329 may include heated fluid entanglers (e.g., air temperature is higher than room temperature) or steam entanglers, for example. The tacking may be done more frequently for a specific look desired.
[0077] After being individually tacked with a tacking device 329, the bundle 330 is guided to a mixing cam 340 along with other bundles 330 and 330. The mixing cam 340 positions bundles tacked by the tacking device 329 relative to each other prior to being tacked together into a yarn 391 in a final tacking device 380. The mixing cam 340 may be cylindrical and may have an external surface defining a plurality of grooves for receiving and guiding the texturized and tacked bundles.
[0078] FIG. 4 illustrates a multi-component filament 400 that has a trilobal radial cross-sectional shape and includes the first component 422 and the second component 424. In this exemplary embodiment, the first component 422 may a first polymer composition forming a core that may be fully encapsulated by the second polymer composition component 424 forming a sheath. The first component 422 and the second component 424 define trilobal radial cross-sectional shaped filaments.
[0079] The first component 422 may include a first additive, such as a molecular weight enhancer 422a, 422b introduced at a gradient having a higher amount near the lobe 422b than at the center 422a. Similarly, the sheath 424 may have some amount of nucleating agent 424a. While the separate polymer compositions may provide an exploitable differential stress by themselves, these may be exacerbated by the inclusion of the additives. In other embodiments in accordance with the first aspect, the first component 422 may not be fully encapsulated by the second component 424 but may still have differential stresses that may be exploitable to provide desirable crimps, twists, and rotations.
[0080] FIG. 5 illustrates a multi-component filament 500 that also has a trilobal radial cross-section shape. In this exemplary embodiment, the first component 532 forms a core that is fully encapsulated within the second component 534. Here, the first component 532 defines a circular radial cross-sectional shaped filament, while the second component 534 defines a trilobal radial cross-sectional shaped filament. While FIG. 5 illustrates the first component 532 with the circular radial cross-sectional shape centered within the volume of the trilobal radial cross-sectional filament of the second component 534, in other embodiments, the first component 532 may not be centered within the volume of the trilobal cross-sectional filament of the second component 534. As disclosed and taught herein, the first component 532 may be a first polymer composition extruded from a spinneret at a first temperature, while the second component 534 may be a second polymer composition extruded from the spinneret at a second temperature such that they may have exploitable differential stresses between them that will result in desirable crimps and twists as the filament 500 is further processed as shown and described as in exemplary FIGS. 1-3.
[0081] The bicomponent filament 600 shown in FIG. 6 also has a trilobal radial cross-sectional shape and includes first polymer composition 642 with lobes 644 of a different polymer composition. The lobes 644 may be comprised of the second polymer composition with one of the lobes further comprising a nucleating agent 644a. The lobe having the nucleating agent 644a may then have an exploitable differential stress that will result in desirable crimps and twists as the filament 600 is further processed as shown and described as in exemplary FIGS. 1-3.
[0082] FIG. 7 illustrates another example of multi-component filament 700, where the first component 752 comprises a first polymer composition with an IV enhancer 752a and a dispersion of nucleating agents 752b dispersed therein. The second component 754 defines a radial cross-sectional shape that is substantially similar to an individual lobe of a trilobal filament, and strands of the second component 754 are coupled to various portions of the first component 752.
[0083] FIG. 8 illustrates another example of a core/sheath filament 800. The first component 862 comprises a core of a first polymer composition and the second component 864 comprises a sheath of a second polymer composition that fully encapsulates the core. The first component 862 and the second component 864 both have circular radial cross-sectional shapes, and the first component 862 is centered within the volume of the second component 862. The first component 862 includes the first additive 862a and second additive 862b dispersed within the second polymer composition. Processing this filament 800 as disclosed herein and within the steps illustrated within exemplary FIGS. 1-3 may exploit differential stresses between the first component 862 and the second component 864 to produce desirable crimps and twists.
[0084] The core/sheath multi-component filament 900 in FIG. 9 is similar to the filament 800 in FIG. 8 in that the first component 972 is fully encapsulated by the second component 974 and components 972, 974 have circular radial cross-sectional shapes, but the first component 972 is not centered within the volume of the second component 974. The first component 972 includes the first polymer composition 972a and a molecular weight enhancer 972b dispersed within the second polymer composition 972a, and the second component 974 includes the second polymer 974a. The filaments 800, 900 of FIG. 8 and FIG. 8 have a circular radial cross-sectional shape, but in other embodiments in accordance with the first aspect, the filaments may have other radial cross-sectional shapes, such as those described herein. In addition, these filaments 800, 900 have a circular shaped first component 862, 972 as viewed in the radial plane, but the first components in other embodiments in accordance with the first aspect may have other radial cross-sectional shapes, such as those described herein, and/or may define one or more voids therethrough.
[0085] As another example, in the multi-component filament 1000 shown in FIG. 10, the first component 1082 and the second component 1084 have a semi-circular shaped radial cross-section with a circular shaped axial void 1086 that is centered within the filament 1000. The first component 1082 and the second component 1084 are coupled together along flat surfaces of each component 1082, 1084 along a plane that includes the central axis 1088 of the filament 1000. An external surface of the filament 1000 has a circular radial cross-sectional shape. The first component 1082 includes the first polymer composition 1082a and a first additive 1082b dispersed within the first polymer composition 1082a, and the second component 1084 includes the second polymer 1084a which may not include any additives. While the differential stress of bonding the components 1082, 1086 together may cause some crimping and twisting while being further processed, the addition of the additives 1082a, 1082b may exacerbate or inhibit the differential stress as disclosed elsewhere herein to provide a predictable level of crimp and/or twists that may be exploited.
[0086] The bicomponent filament 1100 shown in FIG. 11 is similar to the bicomponent filament 1000 in FIG. 10, but the circular-shaped component 1196 is a third polymer composition within the filament 1100. The first component 1192 includes the first polymer composition 1192a and additives 1192b dispersed within the second polymer composition 1192a. The second component 1194 includes the second polymer composition 1194a. The interactions of being processed after extrusion as disclosed herein may produce desirable crimps and twists from their own differential stresses between the components 1192, 1194, 1196. However, this may be exacerbated with the inclusion of an additive such as a flow aid within the first component 1192. It will also be within the scope of the inventions disclosed and taught herein if the second component 1194 and the circular-shaped component 1196 have the same polymer compositions, but that they are extruded at different temperatures or pressures, or that one is extruded from the spinneret at a different capillary depth than the other. Those of ordinary skill in the art and in possession of the disclosures and teachings herein will understand the plethora of other embodiments that are within the scope of the inventions disclosed herein.
[0087] The multi-component filament 1200 shown in FIG. 12 has a circular radial cross-sectional shape and defines an axial void 1206 that is centered in the filament 1200. The first component 1202 and the second component 1204 are arranged circumferentially around the central axis of the filament 1200 in alternating radial segments. For example, the filament 1200 has sixteen radial segments, wherein the first component 1202 and the second component 1204 are alternately arranged around a central axis and void 1206 of the filament 1200. The first component 1202 includes the first polymer composition 1202a and additive 1202b dispersed within the second polymer composition 1202a, and the second component 1204 includes the second polymer composition 1204a.
[0088] In other embodiments in accordance with the first aspect, the filament can have four or more alternating segments of the first and second components and no axial voids or more than one axial voids. For example, the bicomponent filament 1500 in FIG. 15 shows an example of a multi-component filament 1500 having no axial voids but includes the circumferential arrangement of the first component 1532 and the second component 1534 in alternating radial segments. The first component 1532 includes the first polymer composition 1532a and a first additive 1532b dispersed within, and the second component 1534 includes the second polymer composition 1534a. In addition, the angle of each segment in the filaments 1200 and 1500 are the same, but in other embodiments in accordance with the first aspect, the angle of each segment may be varied relative to the other segments to increase the amount of surface area on the exterior surface of the filament thereby causing more exploitable differential stresses between the surface areas within the filaments 1200, 1500.
[0089] The multi-component filament 1300 shown in FIG. 13 has a circular radial cross-sectional shape and includes a first component 1302 and a second component 1304. The components are repeated layer-by-layer across the diameter of the filament 1300. Each layer of the first component 1302 may be comprised of a first polymer composition 1032a and an additive 1302b. Each layer of the second component may be comprised of a second polymer composition 1304a. The layer-by-layer segmentation of the two components may have exploitable differential stresses between the surface areas of the layers 1302, 1304 as they repeat.
[0090] The multi-component filament 1400 shown in FIG. 14 has a circular radial cross-sectional shape and includes a first component 1422 and a second component 1424. The first component 1422 is mostly encapsulated by the second component 1424 but a portion of the first component 1422 extends to the exterior surface of the filament 1400. The first component 1422 includes the first polymer composition 1422a and at least one additive 1422b dispersed within, and the second component 1424 includes the second polymer composition 1424a.
[0091] The bicomponent filament 1600 shown in FIG. 16 has a circular radial cross-sectional shape and includes first component 1642 and second component 1644. The second component 1644 comprises multiple strands extending axially through the first component 1642, and the first component 1642 encapsulates the second component 1644 strands. Some of the strands of the second component 1644 are circumferentially arranged in rings 1644a-f, and the rings 1644a-f are radially spaced from each other and centered with respect to a central strand 1644a, which extends along the central axis of the filament 1600. The first component 1642 includes the first polymer composition and any additive 1642b dispersed within. The second component 1644 includes the second polymer 1644a-f.
[0092] In other embodiments according to the first aspect, the filaments illustrated in these figures may include more than two components and/or have any radial cross-sectional shape, including any of the shapes described herein.
[0093] The present invention is in no way limited to the herein above-described embodiments, on the contrary many such melt spun bicomponent filament and methods may be realized according to various variants, without leaving the scope of the present invention.
