Film winding core, and wound film body using same

Abstract

A film winding core ( 10 ) of the present invention includes a core body ( 12 ) and a plurality of film supporting portions ( 14 ). The core body ( 12 ) has a tubular shape. The plurality of film supporting portions ( 14 ) are provided around the core body ( 12 ). The film supporting portions ( 14 ) protrude from the outer peripheral surface ( 12 p ) of the core body ( 12 ) respectively at a plurality of positions in a rotational direction of the core body ( 12 ) so that a film ( 18 ) is supported away from the outer peripheral surface ( 12 p ) of the core body ( 12 ). Each of the film supporting portions ( 14 ) is made of a material that can be deformed when the film ( 18 ) is wound on the film winding core ( 10 ).

1 . A film winding core on which a long film is to be wound, comprising:
 a core body having a tubular shape; and   a plurality of film supporting portions provided around the core body, the film supporting portions protruding from an outer peripheral surface of the core body respectively at a plurality of positions in a rotational direction of the core body so that the film is supported away from the outer peripheral surface of the core body, and each of the film supporting portions being made of a material that can be deformed when the film is wound on the film winding core.   
     
     
         2 . The film winding core according to  claim 1 , wherein the material is an elastically deformable material. 
     
     
         3 . The film winding core according to  claim 1 , wherein the material comprises at least one selected from the group consisting of sponge, rubber, and foam. 
     
     
         4 . The film winding core according to  claim 1 , wherein the film supporting portions are arranged at regular intervals in the rotational direction. 
     
     
         5 . The film winding core according to  claim 1 , wherein the positions of the film supporting portions, the number of the film supporting portions, and a height of the film supporting portions protruding from the outer peripheral surface of the core body are adjusted so that the core body fits within a polygon having a minimum area required to surround all the film supporting portions in a cross-section perpendicular to a rotational axis of the film winding core. 
     
     
         6 . The film winding core according to  claim 1 , wherein
 the film supporting portions are each provided so as to extend from one side of the core body to the other side of the core body, and   a longitudinal direction of the film supporting portion is parallel to a rotational axis of the film winding core.   
     
     
         7 . The film winding core according to  claim 1 , wherein the film supporting portion has a shape of a semicircular column, a rectangular column, or a hollow semicircular column. 
     
     
         8 . The film winding core according to  claim 1 , further comprising a pair of bearing portions which are mounted on both sides of the core body and into which a shaft used to rotate the film winding core is to be inserted. 
     
     
         9 . The film winding core according to  claim 8 , wherein the bearing portions are constituted by a pair of flanges each having a bearing hole and being detachable from the core body. 
     
     
         10 . A wound film body comprising:
 the film winding core according to  claim 1 ; and   a long film wound on the film winding core.   
     
     
         11 . The wound film body according to  claim 10 , wherein the film is a film produced using an extruder equipped with a T-die. 
     
     
         12 . The wound film body according to  claim 11 , wherein the film is a porous resin membrane.