Plastics and Rubber WACKER Presents New Self-Adhesive Liquid Silicone Rubber with High Elastic Recovery
WACKER, the Munich-based chemical group, will be at the 20th International Trade Fair for Plastics and Rubber K 2016, presenting a new self-adhesive liquid silicone rubber that cures within a very short time to form an oil-bleeding elastomer with high elastic recovery. ELASTOSIL® LR 3072/50 is particularly suitable as a sealing in two-component molded parts. Typical areas of application include automotive electronics and electrical systems, where the product is used in singlewire seals and connector housings with radial seals applied by injection molding. K 2016 will take place in Düsseldorf, Germany, from October 19 to 26, 2016.
The new product expands WACKER’s ELASTOSIL® LR 3072 product line to include a material with high elastic recovery and extraordinarily low compression set. This means that when a molded part made from the silicone elastomer is compressed and then relaxes, deformation is kept to a minimum thanks to its elasticity and elastic recovery.
The compression set and thus long-term deformation of vulcanized parts made of ELASTOSIL® LR 3072/50 are only ten percent after 22 hours of storage at 125 degrees Celsius. They also retain their function at high temperatures. In addition, cured rubber products made from ELASTOSIL® LR 3072/50 remain flexible and elastic at temperatures as low as -50 degrees Celsius. The new liquid silicone rubber grade is thus ideal for sealing applications in the engine compartment or car body.
With a Shore A hardness value of 50, cured rubber products made from the new oil-bleeding silicone are harder and, as a result, somewhat more rigid than existing grades in this product line. ELASTOSIL® LR 3072/50 reliably seals cable bushings and connector housings with lamellar radial seals, where the housing halves are designed to have a gap.
As a markedly shear-thinning, rapidly curing compound, the new liquid silicone is suitable for use in highly automated injection molding processes. Because it is formulated to be self-adhesive, ELASTOSIL® LR 3072/50 bonds to a number of thermoplastics, such as polyamide (PA) and polybutylene terephthalate (PBT), which are frequently used as the hard component of two-component molded parts. The silicone forms an outstanding bond without a primer coat – even on several metals. This means that the liquid silicone rubber can be molded directly onto these types of substrates in an injectionmolding machine, provided the machine and the mold technology are suitable. The result is a fast, affordable means of mass producing thermoplastic/silicone-elastomer or metal/silicone-elastomer composite parts.
Once it has cured and adhesion has developed, ELASTOSIL® LR 3072/50 forms a thin film of silicone fluid, which lubricates the surface of the rubber. This means, for example, that customers can easily thread a cable through an injection-molded, single-wire seal made of ELASTOSIL® LR 3072.
Visit WACKER at K 2016 in Hall 6, Booth A10.