Zipper tape, packing bag with zipper tape and apparatus for producing packing bag with zipper tape

摘要

A zipper tape includes a pair of a male member and a female member including engagement portions and belt-like bases, continued to the engagement portions. The belt-like base includes a seal base defined by widening the belt-like base a larger width from the engagement portions to a crosswise end of the belt-like base than that of the belt-like base. A bond layer and an easy-peel layer are layered on a surface of the seal base in side of the engagement portion and heat-fused to a bag body. The seal base is formed of polypropylene. The bond layer is formed of a mixture of polypropylene and low density polyethylene. The easy-peel layer is formed of a mixture of low density polyethylene and polypropylene. A ratio of polypropylene in the easy-peel layer is smaller than a ratio of polypropylene in the bond layer.