Melt spun biocomponent filament and method for manufacturing a melt spun biocomponent filament

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.

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.