Filling method, manufacturing method of liquid sachet package, and liquid sachet package

Abstract

The invention is a filling method in which liquid is filled and sealed into a liquid sachet package made of a multilayered laminate having at least three layers in which a base material which forms a surface layer, an intermediate layer, and a sealant layer which forms an internal layer are laminated in the above order, including a process of forming a liquid sachet package, a process of filling liquid, and a process of sealing in the opening of the liquid sachet package, in which the intermediate layer is formed using a composition including an ionomer of an ethylene and unsaturated carboxylic acid copolymer, and a filling temperature range obtained using a specific method becomes equal to or more than 30° C. at both a line speed of 20 m/minute and a line speed of 25 m/minute.

1 . A filling method in which liquid is filled and sealed into a liquid sachet package made of a multilayered laminate having at least three layers in which a base material which forms a surface layer, an intermediate layer, and a sealant layer which forms an internal layer are laminated in the above order, comprising:
 a process of forming a liquid sachet package by overlapping the multilayered laminate in a manner in which a surface of the sealant layer is made to face each other, and performing heat-sealing of a portion which forms a circumferential edge portion of the liquid sachet package;   a process of filling liquid through an opening of the liquid sachet package; and   a process of sealing a heat-sealing portion in the opening of the liquid sachet package filled with the liquid through heat sealing,   wherein the intermediate layer is formed using a composition including an ionomer of an ethylene and unsaturated carboxylic acid copolymer, and   a filling temperature range obtained using a method described below becomes equal to or more than 30° C. at both a line speed of 20 m/minute and a line speed of 25 m/minute.   (Method)   Under conditions that a thickness of the base material is made to be 5 μm to 60 μm, a thickness of the intermediate layer is made to be 5 μm to 50 μm, a thickness of the sealant layer is made to be 5 μm to 50 μm, a total thickness is made to be equal to or less than 100 μm, water at a liquid temperature of 30° C. is filled through the opening of the liquid sachet package, and the heat-sealing portion in the opening of the liquid sachet main body is heat-sealed at an arbitrary heat-sealing temperature using DANGAN TYPE-III (manufactured by Taisei Lamick Co., Ltd.) under conditions of a line speed set to 20 m/minute or 25 m/minute, a left pressure of a sealing roll set to 270 kPa, and a right pressure set to 230 kPa. It should be noted that, a heat sealing temperature is changed in intervals of 5° C.; and   in the heat-sealing portion in the opening of the liquid sachet main body, the heat sealing temperature (an upper limit temperature) immediately before bubbles occur and the heat sealing temperature (a lower limit temperature) at which the liquid sachet main body passes a pressure-resistance test in which a load of 100 kgf is applied for one minute without leakage and pouch break are measured respectively, and a difference between the upper limit temperature and the lower limit temperature is computed as a filling temperature range (° C.)   
     
     
         2 . The filling method according to  claim 1 ,
 wherein a difference (ΔT 20 −ΔT 25 ) between the filling temperature range (ΔT 20 ) when the line speed is set to 20 m/minute and the filling temperature range (ΔT 25 ) when the line speed is set to 25 m/minute is ±10° C. or less.   
     
     
         3 . The filling method according to  claim 1 ,
 wherein a resin that forms the sealant layer is polyethylene having a density of equal to or less than 910 kg/m 3 .   
     
     
         4 . The filling method according to  claim 1 ,
 wherein a melt flow rate of the intermediate layer at 190° C. under a load of 2160 g is 0.1 g/10 minutes to 50 g/10 minutes.   
     
     
         5 . The filling method according to  claim 1 ,
 wherein the resin that forms the sealant layer is a polyethylene having a melt flow rate of 0.1 g/10 minutes to 20 g/10 minutes at 190° C. under a load of 2160 g.   
     
     
         6 . The filling method according to  claim 1 ,
 wherein the sealant layer is equal to or more than the intermediate layer in thickness.   
     
     
         7 . The filling method according to  claim 1 ,
 wherein a tearing strength of the liquid sachet package, which is measured based on JIS k7128-1:1998, is equal to or less than 2 N.   
     
     
         8 . A manufacturing method of a liquid sachet package,
 wherein a filling method according to  claim 1  is used.   
     
     
         9 . A liquid sachet package manufactured using a filling method according to  claim 1 .