Friction is a common nuisance in many technical processes. The assembly of glands for electrical connectors is no exception. The connectors are made by pushing thin wires through silicone rubber glands. If a wire refuses to glide easily over the silicone rubber surface, fully automated production suddenly grinds to a halt.

Up to now, this problem was circumvented by using self-lubricating liquid silicone rubber which contains silicone fluids to reduce friction. But this creates problems of its own: the finished part starts “sweating.” The wire slides through the gland, but its surface becomes covered with a slight film of the fluid; what’s more, the finished parts may stick to each other. And the automotive industry is increasingly frowning on that.

WACKER materials experts have now developed a completely new recipe for a liquid silicone that has low frictional resistance yet dispenses with the need for fluid.

In addition to the lubricating properties, the new product series features enhanced compression set, which is crucial fo good sealing. And because the new material, which goes by the name of ELASTOSIL^® LR 3065, has a particularly low viscosity and can be injection-molded, it wasn’t long before the silicone’s special properties came to the attention of KraussMaffei, the Munich-based plastics-processing machinery manufacturer.

Indeed, because of its low viscosity, ELASTOSIL^® LR 3065 needs to be processed on machines that offer high-precision dosing and reproducibility. Which just happen to be the very hallmarks of the KraussMaffei EX series.

WACKER rubber experts and KraussMaffei machine specialists collaborated to optimize the interplay of material and technology.

The most popular application of this WACKER material is for connector glands in automotive electrics and electronics. The materials developers from WACKER now have their eyes on another prize: the medical engineering field.

Freedom from silicone fluid is obviously vital there, but the components must also be easy to assemble and offer all the benefits of silicone rubber. Preliminary samples have already drawn a favorable response from the industry.