Abstract: A method of heat sealing a thermoplastic lid to a thermoplastic drum and an article of manufacture comprising a sealed container especially for hazardous and nuclear wastes are disclosed. A pair of flat ribbon resistance wires are encapsulated within a thermoplastic sheath and are arranged in spaced, parallel, substantially coplanar relation. For welding together the drum and lid, one or more pairs of encapsulated wires are attached to the lid and are compressed between confronting surfaces of the lid and drum by mean of a drum clamp. A predetermined electric current is passed through the wires to heat the wires and melt the thermoplastic sheath. As the thermoplastic sheath melts, the pressure exerted by the drum clamp squeezes the molten thermoplastic material radially inwardly and outwardly along the confronting surfaces of the lid and drum.

Abstract: A molded polyethylene salvage drum for containing hazardous wastes has a container having a solid side wall and a lid having a circular double-walled body. The container has a top portion provided on its exterior surface with male threads, an enlarged portion adjacent the threads, and a lower side wall portion adjacent the enlarged portion. An annular shoulder is formed on the container between the portion of enlarged diameter and the lower side wall. The lid has a skirt depending from the body of the lid. The interior surface of the skirt is provided with female threads mating with the male threads of the container. Castellations project upwardly from the lid body around the periphery thereof. The lid is molded so as to provide a plurality of kiss-off sections, in which the two walls of the body are molded together during rotational molding of the lid.

Abstract: A method and device for heat sealing thermoplastic materials is disclosed. A pair of flat resistance wires are encased within a plastic sheath and arranged in parallel with their flat surfaces lying in one plane. The wires are spaced from each other in a manner designed for maximum thermal emission. To weld together two thermoplastic materials, the sheathed wires are held between and in firm contact with the materials to be joined. A predetermined electric current is passed through the wires until enough heat has been generated to weld the materials together. The invention may also be applied to a process for heat sealing plastic lids to plastic drums. In particular, the sheathed wires are fastened to the lower surface of a thermoplastic drum lid. The lid, together with the resistance wires is clamped to a thermoplastic drum with a standard drum clamp. An electric current is passed through the wires for a period of time sufficient to heat up the wires and weld the lid to the drum.