1
Lester D Siebert: Preheater for heat-sealing system for plastic containers. Uly Pak, Jones Tullar & Cooper, August 15, 1989: US04856989 (11 worldwide citation)

A preheater assembly for softening a selected portion of plastic stock material prior to severing and edge sealing is disclosed. The preheater assembly includes a pair of opposed preheaters, each having a heater tip connected to a source of heated air. The air flows through the tip to maintain it at ...


2
Howard H Keith: Heat-sealing system for plastic containers. Uly Pak, Jones Tullar & Cooper, November 12, 1974: US3847711 (10 worldwide citation)

A plastic container is provided with a plastic bead seal at the junction of the interlocking fastener and the side edges of the container. The plastic bead seal acts as a barrier to the passage of fluids or contaminating bacteria through the fastener at this junction. A method and apparatus are prov ...