Ram extrusion

Ram extrusion is a special sintering process used to manufacture profiles and semi-finished products from extremely ultra-high-molecular-weight polyethylene (UHMWPE). These materials are characterised by exceptionally long molecular chains, which give them outstanding mechanical properties. Because of these properties, UHMWPE materials cannot be melted in a conventional screw machine and therefore cannot be processed by standard screw extrusion.

Instead, in ram extrusion the powdered raw material is sintered by applying heat and pressure.

The process in detail: First, the powdered polyethylene is fed to the sintering tool via a vibrating chute. This vibrating chute ensures that the powder enters the processing zone evenly and continuously. The powder is then pressed into the sintering tool by a pulsating ram piston. The ram piston exerts cyclical pressure on the material, thereby compacting the powder.