Self-standing bag and method of manufacturing the bag

Abstract

A self-standing bag ( 1 ) having a spout ( 3 ) on a bag body ( 2 ), characterized in that both side edges ( 2 a , 2 a ) and an upper edge ( 2 b ) of the bag body ( 2 ) are sealed by an edge sealer ( 4 ) of thermoplastic resin covering the outer surfaces of the edges, and the spout ( 3 ) is formed integrally with the edge sealer ( 4 ).

1 . A self-standing bag having a spout at an upper portion of a bag body, characterized in that both side edges and an upper edge of said bag body are sealed by an edge sealer made of thermoplastic resin which covers the outer surfaces of said edges, and said edge sealer is integrally molded with said spout.  
   
   
       2 . The self-standing bag as set forth in  claim 1 , wherein said edge sealer of said bag body and said spout are formed by injection molding.  
   
   
       3 . The method of manufacturing a self-standing bag as set forth in  claim 1 , characterized in that, in case of forming said edge sealer of said bag body, cavities are formed in a mold at the places corresponding to said edges of said bag body, and then a thermoplastic resin is injected into the cavities to seal said edges of said bag body, thereby forming said edge sealer.  
   
   
       4 . The method of manufacturing a self-standing bag as set forth in  claim 1 , characterized in that, in case of forming said edge sealer of said bag body, a die slide injection system is used in which one cavity in the shape of a half part of said edge sealer is formed in the mold at the place corresponding to one surface of said edges of said bag body, and a thermoplastic resin is injected into said cavity to mold a half part of said edge sealer, then another cavity in the shape of the remainder part of said edge sealer is formed in the mold at the place corresponding to the other surface of said edges of said bag body, and a thermoplastic resin is injected into said cavity to mold the remainder part of said edge sealer to seal said edges of said bag body, thereby forming said edge sealer.