PURPOSE: To improve the transparency and design of a container and facilitate heat sealing between the body and a lid at the time of packaging by a method wherein the innermost layer of the container formed by drawing a laminated sheet is composed of polyester resin, and this resin requires a specific time until a crystallization peak appears when its temperature is raised.
CONSTITUTION: A formed container is provided with a polyester resin layer on its innermost layer to facilitate heat sealing. In order to prevent such polyester resin layer from crystallizing at the time of drawing operation, there is used a polyester low in crystallization rate and, in particular, the polyester whose temperature rises at a rate of 99.9°C/min and which requires at least one minute until a crystallization peak appears when 140°C is maintained, after reaching this temperature, when measured by DSC method (decimal scanning calory method), i.e. by using a scanning type calorimeter. Oxygen-barrier resin and polyester resin are melted in an extruder 11, fed through a feed block 12 into a T-die 13 and ejected therefrom. The laminated sheet obtained in this way is subjected to drawing operation in order to form a container.
YAMANO YASUHIKO
MURATA YASUTOSHI
YAFUSA KAZUYA
KATO TAKEO
