MOULDING OF HOLLOW ITEMS

摘要

A mould for use in the moulding of a hollow item, where the hollow item has an internal recess in the inner face, the mould comprising a substantially central former (15) which has parallel and/or tapered side walls, the mould further comprising an resiliently deformable former (17, 19, 21, 23)received over the central former and supported by a portion of the central former to be retained in position to be resistant to at least some axial movement on the central former, the outer radial face of the deformable former being shaped to form a recess in the internal surface of the moulded item. The deformable former is formed of a resiliently deformable material which is resistant to the heat and/or pressures generated during the moulding process. The central former being capable of axial movement out of engagement with the deformable former on completion of the moulding of the hollow item to leave the deformable former in the hollow item for subsequent removal. In another form the mould further includes a mould body (11) which receives the central former to define a generally annular moulding chamber between the central former and the mould body. In another form the invention includes a method of moulding.