Method for the reduction of color variation in space-dyed yarn

Abstract

A method for reducing variation in depth of shade, intensity and hue in space-dyed yarn comprises: injecting at least two liquid dye compositions into selected portions of a package of yarn to produce a yarn having different colors along the length of said yarn, preheating said yarn to a temperature of about 120°-200° F. using microwaves or radiofrequency, and heating said yarn to a temperature sufficient to fix said dye on said yarn.

1 . A method for space dyeing yarn which comprises 
 injecting two or more liquid dye compositions into selected portions of a wound package of yarn to produce a yarn having different colors along the length of said yarn,    preheating said yarn to a temperature of about 120°-200° F. by subjecting said yarn to microwave or radiofrequency heating, and    heating said preheated yarn at a temperature and for a time sufficient to fix said dye on said yarn.    
     
     
         2 . A method according to  claim 1 , wherein the yarn comprises polyester, nylon, acrylic, or wool.  
     
     
         3 . A method according to  claim 1 , wherein said yarn is preheated using microwave heating.  
     
     
         4 . A method according to  claim 1 , wherein said yarn is preheated using radiofrequency heating.  
     
     
         5 . A method according to  claim 1 , wherein said preheated yarn is heated with steam to fix said dye.  
     
     
         6 . A method according to  claim 5 , wherein said steam heat heats said yarn to a temperature of between about 200°-275° F.  
     
     
         7 . A method according to  claim 2 , wherein said yarn comprises polyester yarn and is subjected to microwave or radiofrequency heating to a temperature of about 120°-180° F. and subsequently subjected to steam heat at a temperature of about 265°-275° F. for a period of time sufficient to fix said dye on said yarn.  
     
     
         8 . A method according to  claim 2 , wherein said yarn comprises acrylic, nylon or wool and is subjected to microwave or radiofrequency heating to a temperature of about 180°-200° F. and subsequently subjected to steam heat at a temperature of about 200°-220° F. for a period of time sufficient to fix said dye on said yarn.  
     
     
         9 . A method according to  claim 1 , wherein said yarn comprises polyester and said dye composition comprises a dispersed dye.  
     
     
         10 . A method according to  claim 9 , wherein said dye composition further comprises at least one dispersant, antimigrant, pH buffer, or wetter to promote dye fixation on said yarn.  
     
     
         11 . A method according to  claim 1 , wherein said yarn comprises wool or nylon and said dye composition comprises an acid or pre-metallized acid dye.  
     
     
         12 . A method according to  claim 11 , wherein said dye composition further comprises at least one wetter or pH control agent to promote dye fixation on said yarn.  
     
     
         13 . A method according to  claim 1 , wherein said yarn comprises an acrylic and said dye composition comprises a basic dye.  
     
     
         14 . A method according to  claim 13 , wherein said dye composition further comprises at least one retardant, pH control agent or wetter to promote dye fixation on said acrylic yarn.  
     
     
         15 . A method according to  claim 1 , wherein said yarn is an acrylic, wool or nylon yarn and said preheated yarn is heated in said microwave or radiofrequency heater to fix said dye on said yarn.  
     
     
         16 . A method according to  claim 15 , wherein said preheated yarn is heated to a temperature of about 200°-212° F. to fix said dye to said yarn.