SEALING OF RECLOSABLE PLASTICS BAGS

摘要

A heat sealing jaw (10), particularly for use in a form-fill-seal machine for the sealing of plastics bags incorporating a zipper seal, comprises a plurality of spaced heat sealing wires (12) in its active surface and a plurality of pressure switches (13) underlying the wires. When the jaw is moved into contact with the zipper and an overlying host material the zipper imparts pressure to a switch or switches and this effects heating of a predetermined wire or wires to create the seal at the correct position. Thus, the seal is made at the correct position even if the position of the zipper on the host material should change. A pair of aligned jaws (10) are preferably used, one on each side of the host material.