SYNTHETIC RESIN CUP, AND METHOD AND DEVICE FOR FORMING MOUTH THEREFOR

摘要

PURPOSE:To improve external appearance of the mouth of a cup while smoothing its touches to lips and preventing injuries from inflicting on the lips by a method wherein a projection caused by downward returning on the front edge of a flange formed to the mouth by downward and inward turning is not allowed to exist. CONSTITUTION:The front end of an outward-looking flange 4 provided to the upper end of a cylindrical part is bent downward and turned round inwardly, and a front end piece 4a of the flange 4 is formed so that it can be bent to form an up-grade. Thereby, the front end piece 4a of the flange 4 forming the mouth of a cup 1 is not allowed to project downward.