Staple fibers and processes for making same

Abstract

Improved staple fibers and processes for producing them are provided. The processes are particularly useful for forming staple fibers from poly(trimethylene terephthalate), especially carpet staple fibers. The processes include prewetting undrawn yarns and drawing the fibers under wet and warm conditions, thermo-fixing the texture, and drying at relatively low temperatures. Fibers produced according to the processes disclosed herein have improved properties and reduced brittleness as compared to fibers prepared using conventional processes.

1 - 30 . (canceled) 
   
   
       31 . A poly(trimethylene terephthalate) textile staple fiber of 1 to 6 dpf, having a tenacity of at least about 3.0 gpd and a crimp take-up from about 15% to about 60% wherein the staple fiber is prepared by a process comprising: prewetting a undrawn yarn consisting essentially of poly(trimethylene terephthalate) at a temperature less than about 45° C.; drawing the fiber under wet conditions at a temperature of from about 45° C. to about 95° C. in a first stage to a length of about 30 to about 90 percent of its final length; drawing the fiber in a second stage at a temperature from about 45° C. to about 98° C. under wet conditions; crimping the drawn fiber; thermo-fixing the crimped fiber in the presence of steam at a temperature from about 80° C. to about 100° C.; and drying the crimped fiber at 60° C. to 140° C. 
   
   
       32 . A poly(trimethylene terephthalate) carpet staple fiber of 6 to 25 dpf, having a length of about 6 to 8 inches, a tenacity of at least about 2.2 gpd and a crimp take-up from about 10% to about 60%. 
   
   
       33 . A 6 to 20 dpf poly(trimethylene terephthalate) staple fiber according to  claim 32 . 
   
   
       34 . A poly(trimethylene terephthalate) fiber of  claim 31  wherein said tenacity is 3.2 gpd or greater. 
   
   
       35 . A poly(trimethylene terephthalate) fiber of  claim 32  wherein said tenacity is 2.4 gpd or greater. 
   
   
       36 . An apparel poly(trimethylene terephthalate) fiber of  claim 31  wherein said crimp take-up is from about 30% to about 50%. 
   
   
       37 . A carpet poly(trimethylene terephthalate) fiber of  claim 32  wherein said crimp take-up is from about 15% to about 45%. 
   
   
       38 . A yarn prepared from a fiber of  claim 31 . 
   
   
       39 . A fabric made from a yarn of  claim 38 . 
   
   
       40 . A textile or non-woven fabric of  claim 39  further comprising one or more fibers selected from cotton, rayon, PET, polypropylene, poly(lactic acid), nylon, acrylic, spandex, acetate, wool, and polybutylene terephthalate fibers. 
   
   
       41 . A yarn prepared from a fiber of  claim 32 . 
   
   
       42 . A carpet, rug or nonwoven fabric prepared from a fiber of  claim 41 . 
   
   
       43 . A carpet, rug or nonwoven fabric of  claim 42  further comprising one or more fibers selected from cotton, PET, polypropylene, poly(lactic acid), nylon, acrylic, wool, and polybutylene terephthalate fibers. 
   
   
       44 . A fiber according to  claim 31 , comprising an anti-static agent. 
   
   
       45 . A fiber according to  claim 32 , comprising an anti-static agent.