Poly(trimethylene terephthalate) bicomponent fiber process

Abstract

A process for the preparation of a side-by-side or eccentric sheath-core bicomponent fiber wherein each component comprises a different poly(trimethylene terephthalate) composition.

1 . (canceled)  
     
     
         2 . (canceled)  
     
     
         3 . (canceled)  
     
     
         4 . (canceled)  
     
     
         5 . (canceled)  
     
     
         6 . (canceled)  
     
     
         7 . (canceled)  
     
     
         8 . (canceled)  
     
     
         9 . (canceled)  
     
     
         10 . (canceled)  
     
     
         11 . (canceled)  
     
     
         12 . (canceled)  
     
     
         13 . (canceled)  
     
     
         14 . (canceled)  
     
     
         15 . (canceled)  
     
     
         16 . (canceled)  
     
     
         17 . (canceled)  
     
     
         18 . (canceled)  
     
     
         19 . (canceled)  
     
     
         20 . (canceled)  
     
     
         21 . (canceled)  
     
     
         22 . (canceled)  
     
     
         23 . (canceled)  
     
     
         24 . (canceled)  
     
     
         25 . (canceled)  
     
     
         26 . (canceled)  
     
     
         27 . (canceled)  
     
     
         28 . (canceled)  
     
     
         29 . A process for preparing poly(trimethylene terephthalate) bicomponent self-crimping yarn comprising poly(trimethylene terephthalate) bicomponent filaments, comprising: 
 (a) preparing partially oriented poly(trimethylene terephthalate) multifilament yarn,    (b) winding the partially oriented yarn on a package,    (c) unwinding the yarn from the package,    (d) drawing the bicomponent filament yarn to form a drawn yarn,    (e) annealing the drawn yarn, and    (f) winding the yarn onto a package    wherein the partially oriented poly(trimethylene terephthalate) multifilament yarn is prepared by:    (i) providing two poly(trimethylene terephthalate) melts,    (ii) altering the intrinsic viscosity of at least one of said polymers such that after alteration, said polymers have intrinsic viscosities that differ by at least about 0.03 dL/g;    (iii) providing the two poly(trimethylene terephthalate) melts to a spinnerette, and    (iv) spinning bicomponent fiber from the poly(trimethylene terephthalate) melts, wherein the fiber is a side-by-side or eccentric sheath-core fiber.    
     
     
         30 . The process of  claim 29 , wherein the process further comprises drawing, annealing and cutting the fibers into staple fibers.  
     
     
         31 . A process for preparing fully drawn yarn comprising crimped poly(trimethylene terephthalate) bicomponent fibers, comprising the steps of: 
 (a) providing two poly(trimethylene terephthalate)s;    (b) altering the intrinsic viscosity of at least one of said polymers such that after alteration, said polymers have intrinsic viscosities that differ by at least about 0.03 dL/g;    (c) melt-spinning the poly(trimethylene terephthalate)s from a spinneret to form at least one bicomponent fiber having either a side-by-side or eccentric sheath-core cross-section;    (d) passing the fiber through a quench zone below the spinneret;    (e) drawing the fiber at temperature of about 50° C. to about 170° C. at a draw ratio of about 1.4 to about 4.5;    (f) heat-treating the drawn fiber at about 110° C. to about 170° C.;    (g) optionally interlacing the filaments; and    (h) winding-up the filaments.    
     
     
         32 . The process of  claim 31 , wherein the two poly(trimethylene terephthalate)s are prepared by: 
 (a) providing two different remelt systems; and    (b) remelting a poly(trimethylene terephthalate) in each of the remelt systems, wherein at least one of the remelt systems is operated so as to provide the poly(trimethylene terephthalate) melts having intrinsic viscosities that differ by at least about 0.03 dL/g.    
     
     
         33 . A process for preparing poly(trimethylene terephthalate) self-crimped bicomponent staple fiber comprising: 
 (a) providing two poly(trimethylene terephthalate)s;    (b) altering the intrinsic viscosity of at least one of said polymers such that after alteration, said polymers have intrinsic viscosities that differ by at least about 0.03 dL/g;    (c) melt-spinning the compositions through a spinneret to form at least one bicomponent fiber having either a side-by-side or eccentric sheath-core cross-section;    (d) passing the fiber through a quench zone below the spinneret;    (e) optionally winding the fibers or placing them in a can;    (f) drawing the fiber;    (g) heat-treating the drawn fiber; and    (h) cutting the fibers into about 0.5 to about 6 inches staple fiber.    
     
     
         34 . The process of  claim 33  wherein the two poly(trimethylene terephthalate)s are prepared by 
 (a) providing two different remelt systems; and    (b) remelting a poly(trimethylene terephthalate) in each of the remelt systems, wherein at least one of the remelt systems is operated so as to provide the poly(trimethylene terephthalate) melts having intrinsic viscosities that differ by at least about 0.03 dL/g.    
     
     
         35 . (canceled)  
     
     
         36 . (canceled)  
     
     
         37 . (canceled)