Prodn. of mould cores from low-melting salt (mixt.) - used in mfr. of tyres from resin hardening into elastic plastics

摘要

Mfr. of mould cores from low-melting salts (mixts) used to male motor vehicle pneumatic tyres or similar mouldings from resins that cure into elastomers in a multipart mould. Method uses an air-tight, heated, container for the salt (mixt) connected via a heat-insulated pipe-line with the lower portion of the mould such that the mould inlet lies at a lower level than the surface of the salt melt in the container. The resulting mould core is dimensionally accurate and has a homogeneous, fine crystalline structure. Post machining of the core is minimised. The mould can be temp-controlled. Its temp. lies normally not more than 100 degrees C below that of the salt melt. The axis of the mould is vertical. As the pipeline opens out into the mould, it pref. narrows.