Process for the manufacture of yarn and the resulting product

Abstract

.[.A process for manufacturing a balanced synthetic yarn, i.e., a yarn having relatively no torque, including the steps of conventionally texturizing yarn formed of thermoplastic filaments, subjecting the yarn to a subsequent heat treatment, and twisting the yarn with a relatively low twist in the opposite direction from the twist imparted to the yarn during the texturizing process..]. .Iadd. A process for the preparation of low-torque textile yarn by imparting high twist to a thermo plastic yarn in one direction and heat setting, detwisting to impart an opposite torque to the yarn, applying a second heat setting to the yarn and then low twisting the yarn in the direction of the torque. .Iaddend.

What is claimed is: 
     
       1. A process for the preparation of low-torque textile yarn comprising, imparting a high twist to a thermoplastic yarn in one direction, heat-setting the yarn in the high twist condition, detwisting the yarn so that a torque in the direction opposite to said high twist is imparted thereto, applying a second heat-setting to the yarn, and thereafter imparting a low twist in the same direction as said torque to the yarn. 
     
     
       2. A process as recited in claim 1 wherein said low twist is of the order of about 100 to 200 turns per meter of yarn. 
     
     
       3. A process as recited in claim 1 wherein said second heat-setting is accomplished at a temperature of the order of about 200° to 300° C for a time of the order of about 1/4 to 1 hour. 
     
     
       4. A process as recited in claim 1 wherein said second heat-setting includes a series of steps including the steps of heating under pressure, exposing the yarn to the ambient atmosphere, and subjecting the yarn to a vacuum atmosphere. 
     
     
       5. A process as recited in claim 1 further including the step of applying an anti-static silicone oil solution to said yarn subsequent to imparting the low twist to the yarn. 
     
     
       6. A process as recited in claim 5 wherein said yarn is coated with said silicone-oil solution so that the weight of the finished yarn comprises 7 to 9 percent of said silicone-oil. 
     
     
       7. A process as recited in claim 1 wherein said second heat-setting includes the steps of steaming for about 4 minutes at about 250° C, exposing the yarn to the ambient atmosphere for about 2 minutes, steaming for about 5 minutes at about 250° C, exposing the yarn to the ambient atmosphere for about 2 minutes, subjecting the yarn to a vacuum for about 5 minutes, exposing the yarn to the ambient atmosphere for about 1 minute, steaming for about 25 minutes at about 250° C, exposing the yarn to the ambient atmosphere for about 1 minute and subjecting the yarn to vacuum for about 5 minutes. 
     
     
       8. A process as recited in claim 1 wherein said low twist is of the order of about 150 turns per meter. 
     
     
       9. A synthetic thermoplastic yarn manufactured according to the process of claim 1. .Iadd. 10. A process for the preparation of low-torque textile yarn suitable for sewing comprising the steps of imparting a high twist to a thermoplastic yarn in one direction, heat-setting the yarn in the high-twist condition, de-twisting the yarn so that a residual torque in the direction opposite to that of said high twist is produced, applying a second heat-setting to the yarn, and thereafter imparting to the yarn a low twist in a direction opposite to that of said high twist. .Iaddend..Iadd. 11. A process as recited in claim 10 wherein said low twist is of the order of about 100-200 turns per meter of yarn. .Iaddend..Iadd. 12. A process as recited in claim 10 wherein said second heat-setting is accomplished at a temperature of the order of about 200°-300° C for a time of the order of about 1/4 to one hour. .Iaddend..Iadd. 13. A process as recited in claim 10 wherein said second heat-setting includes a series of steps including the steps of heating under pressure, exposing the yarn to the ambient atmosphere, and subjecting the yarn to a vacuum atmosphere. .Iaddend..Iadd. 14. A process as recited in claim 10 further including the step of applying an anti-static oil solution to said yarn subsequent to imparting the low twist to the yarn. .Iaddend..Iadd. 15. A process as recited in claim 14 wherein said yarn is coated with a silicone oil so that the weight of the finished yarn comprises 7-9 percent of said silicone oil. .Iaddend. .Iadd. 16. A process as recited in claim 10 wherein said yarn is single-ply. .Iaddend..Iadd. 17. A process as recited in claim 10 wherein said low twist is of the order of about 150 turns per meter. .Iaddend..Iadd. 18. A synthetic thermoplastic yarn manufactured according to the process of claim 10. .Iaddend.