MACHINERY AND EQUIPMENT Using Projectile Injection Technology in the Elastomer Injection Moulding Process

Projectile injection technology (PIT) is a new approach for the production of hollow rubber parts that is already used in thermoplastics processing. However, there have been very few investigations on the PIT processing behaviour of rubber compounds. The flow and curing behaviours are mainly responsible for the surface quality achievable and residual wall thickness.

Media lines made of rubber are usually produced in a labour-intensive multistage extrusion process shown in Figure 1. The manufacturing begins with the extrusion of the inner liner in the form of a hose that is then cooled in a second step. Subsequently this inner liner is wrapped with a fibre reinforcement for form stability. This material combination is then covered by the outer liner in a second extrusion step. The material can either be the same or a different material than the inner liner based on the application. After a second cooling step, the hose is cut to the needed length and manually pushed onto a mandrel that provides the form of the finished media line. The rack with the numerous mandrels is then placed in an oven or autoclave to vulcanise the rubber hoses. The process is finished with the media lines being deformed from the mandrels.