Tearable tube formed from fluororesin

Abstract

The objective of the present invention is to provide a tube which is formed from a fluororesin and has excellent tearability and inner surface smoothness. A tube formed from a fluororesin according to the present invention is tearable in the longitudinal direction, and is formed from one thermoplastic fluororesin that is different from polytetrafluoroethylenes.

1 . A fluororesin tube having tearing property in a lengthwise direction, the fluororesin tube being formed of one thermoplastic fluororesin different from polytetrafluoroethylene. 
     
     
         2 . The fluororesin tube according to  claim 1 , which has heat shrinkability. 
     
     
         3 . The fluororesin tube according to  claim 1 , which has an inner diameter heat shrinkage ratio of 20% or more when heated in a gas phase at 200° C. for 5 minutes. 
     
     
         4 . The fluororesin tube according to  claim 1 , wherein the thermoplastic fluororesin is a tetrafluoroethylene-hexafluoropropylene copolymer. 
     
     
         5 . The fluororesin tube according to  claim 1 , wherein the thermoplastic fluororesin is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. 
     
     
         6 . The fluororesin tube according to  claim 1 , wherein the inner diameter can be expanded by applying pressure from the inside in a heated state. 
     
     
         7 . The fluororesin tube according to  claim 1 , further including a weld line in the lengthwise direction. 
     
     
         8 . A method for producing a fluororesin tube having tearing property, the method comprising a step of subjecting a thermoplastic fluororesin which is different from polytetrafluoroethylene, to melt extrusion molding, wherein in the melt extrusion molding, a flow path of the molten thermoplastic fluororesin is temporarily branched to form a weld line in a lengthwise direction in the fluororesin tube. 
     
     
         9 . The method for producing a fluororesin tube according to  claim 8 , further comprising a step of expanding an inner diameter of the fluororesin tube by applying pressure from inside the fluororesin tube, while heating the fluororesin tube provided with the weld line.