TRANSVERSE PARTIALLY FIXED FOUR-FLANGED ZIPPER STRIP

摘要

PROBLEM TO BE SOLVED: To reduce possibilities of jam liable to occur at the front end corner of a zipper when a web is moved on a collar at the inside of a forming/filling seal apparatus. SOLUTION: A zipper has such a structure that has an unprocessed narrow band at the front end corners of flanges which are tuck-sealed by a discontinuous seal bar. Thereby, the front end corners of the flanges can be prevented from being curled or flipped.