Gusset bag and spout-attached gusset bag

Abstract

A gusset bag includes: a pair of flat surface portions facing each other; and a pair of side surface portions facing each other and folded inward of the gusset bag. A containing portion used to contain an object is formed using the flat surface portions and the side surface portions. The gusset bag has a side edge-sealing portion in which a side edge portion of a flat surface portion of the flat surface portions and a side edge portion of a side surface portion of the side surface portions are heat-sealed together, and a folded-back portion in which the entire side edge-sealing portion is folded back and affixed to the flat surface portion or the side surface portion that forms the containing portion. The peel strength of the folded-back portion is lower than the peel strength of the side edge-sealing portion.

1 . A gusset bag comprising:
 a pair of flat surface portions facing each other; and   a pair of side surface portions facing each other and folded inward of the gusset bag,   wherein a containing portion used to contain an object is formed using the pair of flat surface portions and the pair of side surface portions,   wherein the gusset bag has a side edge-sealing portion in which a side edge portion of a flat surface portion of the flat surface portions and a side edge portion of a side surface portion of the side surface portions are heat-sealed together, and a folded-back portion in which the entire side edge-sealing portion is folded back and affixed to the flat surface portion or the side surface portion that forms the containing portion, and   wherein the peel strength of the folded-back portion is lower than the peel strength of the side edge-sealing portion.   
     
     
         2 . The gusset bag according to  claim 1 ,
 wherein the peel strength of the side edge-sealing portion is 25 N/15 mm or more, and   wherein the peel strength of the folded-back portion is 10 N/15 mm or less.   
     
     
         3 . The gusset bag according to  claim 1 ,
 wherein the peel strength of the side edge-sealing portion is 2.5 or more times the peel strength of the folded-back portion.   
     
     
         4 . The gusset bag according to  claim 1 ,
 wherein a first flat surface portion of the pair of flat surface portions and the pair of side surface portions are formed of a first film member,   wherein a second flat surface portion of the pair of flat surface portions is formed of a second film member,   wherein two side edge-sealing portions are formed by heat-sealing side edge portions of the pair of side surface portions opposite to the first flat surface portion and side edge portions of the second flat surface portion together, and   wherein the two side edge-sealing portions are affixed to the second flat surface portion forming the containing portion.   
     
     
         5 . The gusset bag according to  claim 4 ,
 wherein two surfaces of the second film member are capable of heat-sealing, and   wherein the two side edge-sealing portions are heat-sealed to the second flat surface portion forming the containing portion.   
     
     
         6 . The gusset bag according to  claim 4 ,
 wherein a seal layer is provided between the side edge-sealing portion and the second flat surface portion forming the containing portion in the folded-back portion.   
     
     
         7 . The gusset bag according to  claim 4 ,
 wherein the first flat surface portion serves as the front surface of the gusset bag, and the second flat surface portion serves as the rear surface of the gusset bag.   
     
     
         8 . The gusset bag according to  claim 1 ,
 wherein lower portions of the pair of flat surface portions and of the pair of side surface portions are configured to form the bottom surface of the gusset bag by being bent inward with respect to the gusset bag.   
     
     
         9 . A spout-attached gusset bag in which a spout is attached to an opening of the gusset bag according to  claim 1 .