Extruding

For the manufacturing of hollow grommets we use a manufacturing technique called “extrusion”. Extrusion means that the rubber compound is continuous injected through a mould by means of an extruder.

An extruder comprises of a heated hollow bush while within a special threaded body pushes the compound forward, making it hot and moldable. The injection mould at the end of the extruder dictates the shape and size of the extruded profile which needs to be (separately) vulcanized in an autoclave after the extrusion process. Vulcanization is an non reversible process which uses cross linking to manufacture the final product. Vulcanization ensures that the profile will keep its shape and determines the final properties of the product.

Time, temperature and pressure during the vulcanization process in  the autoclave are the determining factors. For this purpose Van Kempen has a special large autoclave which is suitable for large and long products.  

The manufacturing of special profiles and rubber compounds, even outside the normal industrial scope, is our specialty. Are you searching for hoses, cable, or hollow seals in high quality in high (or low) production numbers? Please inform for the possibilities or let us advise you on plastic engineering or mould fabrication.