Method and apparatus for manufacturing tube-shaped packages made of flexible material

Abstract

A method for manufacturing tube-shaped packages ( 16 ) made of flexible material, characterized in that an annular portion ( 20 ) is pushed inward in a U-shaped arrangement at at least one closed end ( 17 ) of a tube-shaped package, said annular portion being at least partially heat-sealed to the remaining part of the package at facing portions thereof. An apparatus for carrying out the method. A package obtained with the method and the apparatus.

What is claimed is:  
     
         1 . A method for manufacturing a tube-shaped package having longitudinal sides and a bottom and made of flexible material, wherein the longitudinal sides of the package are sealed prior to forming the bottom, and wherein the bottom is formed by pushing an annular portion of the flexible material inward in a U-shaped arrangement at at least one closed end of the tube shaped package, the U-shaped arrangement having opposing sides that face each other, said annular portion being at least partially heat-sealed to a remaining portion of the package at the opposing sides of the U-shaped arrangement.  
     
     
         2 . The method according to  claim 1  wherein a flexible film is used which is transversely affected by reinforcement bands at the regions where the U-Shaped arrangement is produced during formation.  
     
     
         3 . The method according to  claim 1 , wherein a corresponding contoured element is applied to a hollow bottom.  
     
     
         4 . An apparatus for manufacturing a tube-shaped package, comprising: 
 elements for retaining side walls of the tube-shaped package, the package having at least one closed end and the side walls being sealed to form a closed perimeter prior to forming the closed end;    means that can be inserted axially at least partially in said elements for retaining said side walls so as to form, at said closed end, an annular portion that is folded in a U-like shape; and    means for heat sealing said annular portion folded in a U-like shape.    
     
     
         5 . The apparatus of  claim 4  further comprising narrow conveyor belts for effecting advancement of the package from an outside location.  
     
     
         6 . A package obtained according to the method of  claim 1 , wherein at least a closed lower edge of the package is folded inward in a U-shaped configuration.