Side-by-side self-crimping elastic fiber and preparation method therefor

Abstract

A type of side-by-side self-crimping elastic fiber and preparation method thereof are disclosed. The preparation method includes distributing compatible or partially compatible first fiber-forming polymer melts and second fiber-forming polymer melts, then the fiber is extruded from first spinneret holes and second spinneret holes on the same spinneret. The first fiber-forming polymer melts and the second fiber-forming polymer melts flow into the first spinneret holes through first and second distribution holes, and flow into the second spinneret holes through third and fourth distribution holes, wherein the four distribution holes are cylindrical holes of equal height, the ratio of the diameter of the first distribution holes to the diameter of the second distribution holes is (1.10-1.20):1, and the ratio of the diameter of the third distribution holes to the diameter of the fourth distribution holes is 1:(1.10-1.20).

What is claimed is: 
     
         1 . A method for preparing a side-by-side self-crimping elastic fiber, comprising: distributing a first fiber-forming polymer melt and a second fiber-forming polymer melt according to a specific spinning process, then extracting from first spinneret holes and second spinneret holes on a same spinneret to obtain the side-by-side self-crimping elastic fiber;
 wherein a distribution is to distribute the first fiber-forming polymer melt through first distribution holes while distribute the second fiber-forming polymer melt through second distribution holes into the first spinneret holes, and distribute the first fiber-forming polymer melt through third distribution holes while distribute the second fiber-forming polymer melt through fourth distribution holes into the second spinneret holes;   wherein the first fiber-forming polymer melt and the second fiber-forming polymer melt are compatible or partially compatible;   at entrances of the first distribution holes, the second distribution holes, the third distribution holes, and the fourth distribution holes, wherein an apparent viscosity of the second fiber-forming polymer melt differs from an apparent viscosity of the first fiber-forming polymer melt by no more than 5%;   wherein the first distribution holes and the second distribution holes are equally-high cylindrical holes with a diameter ratio of (1.10-1.20):1, and the third distribution holes and the fourth distribution holes are equally-high cylindrical holes with a diameter ratio of 1:(1.10-1.20);   wherein the specific spinning process is a POY process, an FDY process, a POY-DTY process, or a POY-DT process, wherein the POY process, the FDY process, and the POY-DT process are followed by a relaxation heat treatment of the side-by-side self-crimping elastic fiber.   
     
     
         2 . The method of  claim 1 , wherein a ratio of a mass of the second fiber-forming polymer melt to a mass of the first fiber-forming polymer melt is 50:50. 
     
     
         3 . The method of  claim 1 , wherein each of the first spinneret holes or each of the second spinneret holes is a circular, oval, or “8”-shaped spinneret hole. 
     
     
         4 . The method of  claim 1 , wherein all the first spinneret holes and the second spinneret holes are distributed in concentric circles, and the spinneret holes on a same circle are all the first spinneret holes or all the second spinneret holes. 
     
     
         5 . The method of  claim 1 , wherein the first fiber-forming polymer melt and the second fiber-forming polymer melt are of same materials with different viscosities, or of different materials; wherein materials of the first fiber-forming polymer melt and the second fiber-forming polymer melt are selected from a polyester homopolymer, a polyester copolymer, a polyester modified product, a polyamide homopolymer, a polyamide copolymer, and a polyamide modified product. 
     
     
         6 . The method of  claim 1 , wherein each of the first spinneret holes comprises a first guide hole, a first transition hole, and a first capillary micropore connected sequentially, each of the second spinneret holes comprises a second guide hole, a second transition hole, and a second capillary micropore connected sequentially, the first guide hole is connected with the first distribution holes and the second distribution holes at the same time, and the second guide hole is connected with the third distribution holes and the fourth distribution holes at the same time; wherein the first distribution holes, the second distribution holes, the third distribution holes, and the fourth distribution holes are located on a distribution plate in a third spinning box III, the second fiber-forming polymer melt is transported through a first spinning box to the second distribution holes and the fourth distribution holes, while the first fiber-forming polymer melt is transported through a second spinning box to the first distribution holes and the third distribution holes. 
     
     
         7 . The method of  claim 1 , wherein the relaxation heat treatment has a temperature of 90-120° C., and a time of 20-30 min. 
     
     
         8 . A side-by-side self-crimping elastic fiber prepared by the method of  claim 1 , comprising multiple second fiber-forming polymer/first fiber-forming polymer side-by-side composite monofilaments, and in a same bundle of fibers, wherein a first part of the second fiber-forming polymer/first fiber-forming polymer side-by-side composite monofilaments have a mass ratio of the first fiber-forming polymer melt to the second fiber-forming polymer melt of 3:2 to 2:1, and a second part of the second fiber-forming polymer/first fiber-forming polymer side-by-side composite monofilaments have a mass ratio of the first fiber-forming polymer melt to the second fiber-forming polymer melt of 2:3 to 1:2. 
     
     
         9 . The side-by-side self-crimping elastic fiber of  claim 8 , wherein during a preparation of the side-by-side self-crimping elastic fiber, a ratio of a mass of the second fiber-forming polymer melt to a mass of the first fiber-forming polymer melt is 50:50. 
     
     
         10 . The side-by-side self-crimping elastic fiber of  claim 8 , wherein each of the first spinneret holes or each of the second spinneret holes is a circular, oval, or “8”-shaped spinneret hole. 
     
     
         11 . The side-by-side self-crimping elastic fiber of  claim 8 , wherein all the first spinneret holes and the second spinneret holes are distributed in concentric circles, and the spinneret holes on a same circle are all the first spinneret holes or all the second spinneret holes. 
     
     
         12 . The side-by-side self-crimping elastic fiber of  claim 8 , wherein the first fiber-forming polymer melt and the second fiber-forming polymer melt are of same materials with different viscosities, or of different materials; wherein materials of the first fiber-forming polymer melt and the second fiber-forming polymer melt are selected from a polyester homopolymer, a polyester copolymer, a polyester modified product, a polyamide homopolymer, a polyamide copolymer, and a polyamide modified product. 
     
     
         13 . The side-by-side self-crimping elastic fiber of  claim 8 , wherein each of the first spinneret holes comprises a first guide hole, a first transition hole, and a first capillary micropore connected sequentially, each of the second spinneret holes comprises a second guide hole, a second transition hole, and a second capillary micropore connected sequentially, the first guide hole is connected with the first distribution holes and the second distribution holes at the same time, and the second guide hole is connected with the third distribution holes and the fourth distribution holes at the same time; wherein the first distribution holes, the second distribution holes, the third distribution holes, and the fourth distribution holes are located on a distribution plate in a third spinning box III, the second fiber-forming polymer melt is transported through a first spinning box to the second distribution holes and the fourth distribution holes, while the first fiber-forming polymer melt is transported through a second spinning box to the first distribution holes and the third distribution holes. 
     
     
         14 . The side-by-side self-crimping elastic fiber of  claim 8 , wherein the relaxation heat treatment has a temperature of 90-120° C., and a time of 20-30 min.