Process for the production of a blank for containers and blank produced by the process

Abstract From the Canadian patent

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 …