Yarn having differentiated shrinkage segments and fabrics formed therefrom

Abstract

A multi-filament yarn including interlace nodes disposed along the length of the yarn. The yarn has variable retained heat shrinkage potential at segments along its length such that segments of said yarn containing the interlace nodes have a retained heat shrinkage potential in excess of segments of said yarn between the interlace nodes. Upon application of uniform heat to the yarn, the segments containing the interlace nodes exhibit enhanced shrinkage and self texturing relative to the segments between the interlace nodes. A fabric formed with the yarn prior to the final heating process will present a varied and random appearance after application of the final heating process due to the differentiated shrink segments. Pile fabrics formed with the yarn as the pile yarn prior to the final heat treatment will have piles of varying height due to the differentiated shrink segments, and will also have a varied or random appearance.

1 . A cut yarn pile fabric comprising a base portion and a pile portion, wherein the pile portion comprises a first group of cut yarn piles projecting outwardly from the base portion to a first height and at least a second group of cut yarn piles projecting outwardly from the base portion to a second height lower than the first height, wherein at least a portion of the first group of cut yarn piles and at least a portion of the second group of cut yarn piles are formed from segments of a common yarn and wherein in the fabric the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of yarn filaments characterized by an average cross-sectional area at least 1.56 times the average cross-sectional area of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.  
     
     
         2 . The invention as recited in  claim 1 , wherein the cut yarn pile fabric is a knit fabric.  
     
     
         3 . The invention as recited in  claim 2 , wherein the loop pile fabric is a double needlebar knit fabric.  
     
     
         4 . The invention as recited in  claim 2 , wherein the loop pile fabric is a clip knit fabric.  
     
     
         5 . The invention as recited in  claim 2 , wherein the loop pile fabric is a POL knit fabric.  
     
     
         6 . The invention as recited in  claim 1 , wherein the common yarn is a multi-filament thermoplastic yarn.  
     
     
         7 . The invention as recited in  claim 6 , wherein the material of the common yarn is selected from the group consisting of polyester, polypropylene, and nylon.  
     
     
         8 . The invention as recited in  claim 1 , wherein the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of yarn filaments having a lower degree of crystalline orientation than the yarn filaments in the segments of the common yarn forming the first group of cut yarn piles such that the average level of crystalline orientation of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles as measured by the Herman Orientation Function is at least 5% greater than the average level of crystalline orientation of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles.  
     
     
         9 . The invention as recited in  claim 1 , wherein the segments of the common yarn forming the second group of cut yarn piles are characterized by a substantially non-parallel arrangement of crimped yarn filaments.  
     
     
         10 . The invention as recited in  claim 1 , wherein the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of substantially circular cross-section yarn filaments characterized by an average cross sectional diameter which is at least 50 percent greater than the average cross sectional diameter of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.  
     
     
         11 . The invention as recited in  claim 10 , wherein at least a portion of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles are characterized by a cross sectional diameter which is at least twice the cross sectional diameter of one or more yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.  
     
     
         12 . A cut yarn pile fabric comprising a base portion and a pile portion, wherein the pile portion comprises a first group of cut yarn piles projecting outwardly from the base portion to a first height and at least a second group of cut yarn piles projecting outwardly from the base portion to a second height lower than the first height, wherein at least a portion of the first group of cut yarn piles and at least a portion of the second group of cut yarn piles are formed from segments of a common yarn and wherein in the fabric the segments of the common yarn forming the second group of cut yarn piles comprise a plurality of yarn filaments characterized by an average cross-sectional area which is at least 1.56 times the average cross sectional diameter of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles and wherein the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles are characterized by a lower degree of crystalline orientation than the yarn filaments in the segments of the common yarn forming the first group of cut yarn piles such that the average level of crystalline orientation of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles as measured by the Herman Orientation Function is at least 5% greater than the average level of crystalline orientation of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles.  
     
     
         13 . The invention as recited in  claim 12 , wherein the common yarn is a multi-filament polyester yarn.  
     
     
         14 . The invention as recited in  claim 13 , wherein the average level of crystalline orientation of yarn filaments in the segments of the common yarn forming the first group of cut yarn piles as measured by the Herman Orientation Function is at least 10% greater than the average level of crystalline orientation of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles.  
     
     
         15 . The invention as recited in  claim 12 , wherein the segments of the common yarn forming the second group of cut yarn piles are characterized by a substantially non-parallel arrangement of crimped yarn filaments.  
     
     
         16 . The invention as recited in  claim 15 , wherein at least a portion of the yarn filaments in the segments of the common yarn forming the second group of cut yarn piles are substantially circular cross-sectional filaments characterized by a cross sectional diameter which is at least twice the cross sectional diameter of one or more yarn filaments in the segments of the common yarn forming the first group of cut yarn piles.  
     
     
         17 . A method of forming a cut yarn pile fabric comprising a base portion and a pile portion, wherein the pile portion comprises a first group of cut yarn piles projecting outwardly from the base portion to a first height and at least a second group of cut yarn piles projecting outwardly from the base portion to a second height lower than the first height, the method comprising the steps of: 
 underdrawing a partially oriented multi-filament yarn across a heat source at a rate such that portions of the yarn undergo substantially complete heat setting and other portions do not undergo substantially complete heat setting;    forming the yarn into the cut pile portion of the cut yarn pile fabric; and    heating the fabric such that portions of the yarn which did not undergo substantially complete heat setting during the underdrawing step shrink towards the base portion of the fabric in a crimped self texturing manner.