Leak-proof wide-mouthed plastic drum - has plastic lid with double rim fitting over mouth and extending down externally over outer rib, plus film liners for both drum and lid

摘要

Drum has a removeable lid with an outer rim wrapping round the neck, an inner rim projecting into the neck and beyond the base beneath the mouth of the drum, and a sealing ring between the outer and inner rims of the lid. This ring is tightened against the rim of the drum by another ring which engages a flange beneath on the outer rim of the lid. It engages also a solid rib round the outside of the neck below the mouth; the structure has moreover a flexible liner of plastic film or combination metal/plastic film to hold the filling of the drum, and an inner liner of plastic material to protect the lid. Both the lid liner and the lining holding the contents (the latter having its top rim above the open top of the neck of the drum) are welded together inductively round the rim of the mouth, and an electrically conducting metal is positoned between the sealing rings of the lid and the inner lining. This inner liner of the lid is e.g. aluminium foil-lined polyethylene and the lining of the drum is pref. e.g. polyethylene film. ADVANTAGE - The seal of the drum withstands considerable stresses, e.g. even if the lid becomes loose.