Hot moulding - an interesting forming process

Hot moulding depends on adding thermoplastic binders to the ceramic or metallic powder in order to make it fluent. At temperatures above the melting point of the binder the fluent compound is injected under pressure into a metal mould where it stiffens. After removal of the binder the part is sintered. Unlike injection moulding and thermoplastic extrusion, hot moulding uses only paraffins and low-viscous waxes and binders. The compound is shaped directly in the flowing state by using relative low pressure. The consequent advantages are low energy costs, appreciably less wear at tools and machine parts and considerably less expensive tools. The hot moulding process is accordingly suitable for short to medium production scales. As the thermoplastic binder suffers no damage at the low temperatures and pressures used, recycling the sprue and the remainders of compounds exhibits no problem. Hot moulding gives very high dimensional stability (near net shape), which means either very low fini shing costs or none at all. The low viscosity of the hot moulding slip enables wall thickness of a few tenths of a millimeter , which is not possible with other moulding processes