Plastic drum

Abstract From the Canadian patent

The invention provides a method of forming a blowmoulded drum of thermo-plastics material provided with projecting hoops, comprising, blow-moulding a drum in a mould the mould, being formed of laterally displaceable mould sections which in, a closed position, define a mould cavity having side walls the, mould sections being further divided into separate parts in planes in which drum chimes are to be formed, the separate parts of the mould sections defining between them in an extended position of the mould parts, gaps in the side walls of the mould cavity whereby, during the blow-moulding step material is blown into, the gaps to form annular rings around the drum and contracting, the mould …