摘要 |
A method and a device for production of a temperature-stable, biaxially oriented container of thermoplastic material. In a first moulding stage a blank (40) is placed in a blow mould (12) after which a mandrel (15) extends the blank in its axial direction to a length exceeding the axial length of the future container. The length of the stretched material, in an axial section through the stretched blank, is then reduced at a predetermined temperature, and the reduction being made to a profile length substantially agreeing with the profile length for corresponding material portions in an axial section through the future container. In a second moulding stage the stretched blank is expanded to abut against the walls of the mould. The expansion takes place at a point in time for and/or at a speed allowing the reduction of the length of the stretched material, due to shrinkage to have time to be concluded before the material comes into contact with the walls of the mould. |