Ripcord of optic cables and method of manufacturing the same

Abstract

Disclosed are a ripcord for optic cable and a method of manufacturing the same. The ripcord for optic cable has a coating layer formed by applying a coating solution, which includes a binder and a colorant dispersed in the binder, to a surface of a folded and twisted yarn formed by folding and twisting together wholly aromatic polyamide filaments.

1 . A method of manufacturing a ripcord suitable for an optic cable comprising:
 applying a coating solution, which includes a binder and a colorant dispersed in the binder, to a surface of an assembled and twisted yarn formed by assembling and twisting together wholly aromatic polyamide filaments to form a coating layer; and   winding the coated yarn over a winding machine.   
     
     
         2 . The method according to  claim 1 , further comprising a diluent in the coating solution. 
     
     
         3 . The method according to  claim 2 , wherein the diluent is a combination of water and an evaporation promoter having a boiling point lower than that of water. 
     
     
         4 . The method according to  claim 2 , wherein the diluent is a combination of 1 to 20 wt. % of an evaporation promoter and 80 to 99 wt. % of water. 
     
     
         5 . The method according to  claim 2 , wherein the diluent is at least one selected from the group consisting of an evaporation promoter and water. 
     
     
         6 . The method according to  claim 3 , wherein the evaporation promoter is at least one selected from the group consisting of ethanol, methylethylketone, ether, tetrahydrofuran, acetone and methylalcohol. 
     
     
         7 . The method according to  claim 1 , wherein the coating solution is applied to the surface of the assembled and twisted yarn by passing the assembled and twisted yarn over a rotational coating roller, wherein said rotational coating roller is partially immersed in a tank containing the coating solution. 
     
     
         8 . The method according to  claim 7 , wherein a squeezing roller is mounted on a top of the rotational coating roller to squeeze the assembled and twisted yarn coated with the coating solution. 
     
     
         9 . The method according to  claim 1 , wherein the coating solution is applied to the surface of the assembled and twisted yarn by passing the assembled and twisted yarn over a coating roller fed with the coating solution from a tank containing the coating solution by means of an injector. 
     
     
         10 . The method according to  claim 1 , wherein the assembled and twisted yarn formed by assembling and twisting together wholly aromatic polyamide filaments,
 wherein said yarn comprises (i) 50 to 99 wt. % of the wholly aromatic polyamide filaments and (ii) 1 to 50 wt. % of at least one selected from the group consisting of a polyester filament, polyamide filament, polyvinylalcohol filament, rayon filament, polyolefin filament and polybenzonite filament.   
     
     
         11 . The method according to  claim 1 , wherein the assembled and twisted yarn is dried after forming the coating layer on the surface of the assembled and twisted yarn and before winding the same. 
     
     
         12 . The method according to  claim 11 , wherein the drying process is conducted with a speed ranging from 5 to 1,000 m/min at 150 to 240° C. 
     
     
         13 . The method according to  claim 11 , wherein the drying process is conducted at a speed ranging from 10 to 800 m/min at 150 to 240° C. 
     
     
         14 . The method according to  claim 4 , wherein the evaporation promoter is at least one selected from the group consisting of ethanol, methylethylketone, ether, tetrahydrofuran, acetone and methylalcohol. 
     
     
         15 . The method according to  claim 5 , wherein the evaporation promoter is at least one selected from the group consisting of ethanol, methylethylketone, ether, tetrahydrofuran, acetone and methylalcohol.