METHOD FOR PRODUCTION OF RESIN CAP HAVING SEALANT COMPRISING HOT MELT COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a cap production method capable of effectively preventing protrusion of a sealant in a cap having the sealant consisting of a hot melt composition.SOLUTION: There is provided a cap production method comprising forming an annular sealant consisting of a hot melt composition by spin lining on the outer peripheral edge of a top plate inner face in a polypropylene-made cap shell 1 comprising a top plate part 2 and a skirt part 3 drooping from the peripheral edge of the top plate. The method is characterized by adjusting the wet tension of the formation position of the sealant 20 to 32 mN/m or higher by providing a plasma surface treatment process at least at the sealant formation position of the inner face of the cap shell top plate part 2 before the process of spin-lining the hot melt composition on the inner face of the cap shell.SELECTED DRAWING: Figure 1