| 摘要 |
<p>There is described an apparatus for the manufacture of a tubular pre-moulding from a thermoplastic material. The apparatus can axially stretch a tube of the thermoplastic material to a substantially reduced material thickness in at least a central zone of the tube while substantially maintaining the diameter of the tube in the axially stretched section in the central zone. The reduction is by a factor sufficient to cause yielding and orienting of the material substantially in the axial direction of the future pre-moulding. The apparatus can also effect the axial stretching of the tube at a temperature not greater than the glass transition temperature of the thermoplastic material. A mould surrounds the tube, and the material is heated in one of the oriented zones to a temperature above the glass transition temperature. The material is expanded in the radial direction of the tube until it makes contact with the mould to form a mouth part with adjacent neck section of the pre-moulding, the material then being cooled to a temperature below the glass transition temperature, thereafter heated at one end of the tube to a temperature above the glass transition temperature and formed as a closure at the one end for the premoulding.</p> |
