Method and apparatus for the production of mouldings from thermoplastic material whose partially crystalline state can be adjusted by physical effects, more particularly temperature effects

摘要

Method for the production of mouldings from a thermoplastic material the crystallinity of which can be varied by varying one or more physical parameters, for example temperature, by: forming a semifinished article, stabilizing the semifinished article by cooling of at least one surface thereof, thermally conditioning the stabilized semifinished article to render it thermally deformable, and thermal deforming the thermally conditioned article to obtain a stable moulding, characterised in that the material is such that its crystallinity can be varied between amorphous and partially crystalline states and both the desired crystallinity and also a desired temperature gradient over a cross-section of the semifinished product are established in a wall portion of the semifinished article between the forming and stabilization steps by a first thermal conditioning operation, and in that a second thermal conditioning operation is carried out during the thermal deformation step with control of temperature to produce or maintain the desired final crystallinity in the plastics material of the said wall portion.