High strength thermoplastic moulding - prepd. from e.g. weaker mouldings by heating, subjecting to repeated shaping and shearing, and e.g. compression moulding to final shape

摘要

In the prodn. of thermoplastic mouldings a preform is put through shear processes until it reaches the shape of the moulding, whereby a high mechanical strength prod. is formed by causing appropriate flow and orientation through shear-stretching. In the process a preform of at least partly block shape is heated uniformly but without changes being made to its shape or consistency; it is then subjected one or more times to conversion and shear so that forging effects are produced first, after which the prod. is compression-moulded in a final stage to reach the shape required. ADVANTAGE - The process forms prods. with properties which they do not have when initially made.