METHOD FOR MOULDING PLASTIC SEMIMANUFACTURE AND APPARATUS FOR MOULDING PLASTIC PRODUCTS

摘要

Plastic partic, ceramic substances are shaped on screw presses pref, into hollow bricks. Expansion is imported at the periphery in the region of laminar flow by means of a shaping tool (2, 3) according to relative elastic expansion of the substance of which the extent is reached at the periphery of the blank. The shaping tool is mounted on a base plate (1) and consists of a shaping member (2) and mouthpiece (3). The circumference of the shaping zone, begining at the inlet (e) of the shaping member increases gradually to the outlet (a) at the mouthpiece by the length of elastic expansion of the ceramic substance. Differences in elastic changes in length are thus reduced or eliminated to ensure constant shrinkage in different areas of the blank.