WACKER, the Munich-based chemical group, is showcasing numerous new and time-tested silicone rubber grades at EXPOBOR 2014. ELASTOSIL® LR 3094/60 liquid silicone rubber will be one of the highlights at the WACKER booth. It makes cost-effective, large-scale production of spark plug boots possible. Another eye-catcher will be coolant-resistant ELASTOSIL® LR 3022/60. The liquid silicone rubber, which is presented at EXPOBOR for the first time, can be used to make molded gaskets for engine cooling circuits. Another innovation is magnetite-filled ELASTOSIL® R 781/80 solid silicone rubber. This product enables the manufacture of molded parts and profiles that adhere magnetically. EXPOBOR 2014 will take place from April 23 to 25 in São Paulo, Brazil.
At the WACKER booth, the spotlight will be on ELASTOSIL® LR 3094/60. This fast-curing liquid silicone rubber is designed for cost-effective, large-scale production of spark plug boots. Its rubber-elastic cured rubber grades feature excellent heat resistance, good mechanical properties and very good dielectric properties. Spark plug boots and other technical products made of ELASTOSIL® LR 3094/60 do not require postcuring.
Cured ELASTOSIL® LR 3094/60 rubber grades easily withstand temperatures of –55 to +210 degrees Celsius. A spark plug boot made of this silicone always has the same properties, whatever the temperature to which it is exposed in practice. It has a long service life even under continuous heat exposure. Spark plug boots made of ELASTOSIL® LR 3094/60 offer effective protection against road spray, moisture and dirt. They provide reliable electrical insulation, achieve high dielectric strength and prevent the development of corona effects.
Coolant-Resistant: ELASTOSIL® LR 3022/60
WACKER is also introducing the new ELASTOSIL® LR 3022/60 silicone grade at EXPOBOR. This liquid silicone rubber enables the manufacture of molded gaskets that can be used in automotive engine cooling systems. In its cured state, the new grade retains a low compression set, even under long-term load in direct contact with coolants. This ensures excellent, lasting sealing properties.
Standard silicone elastomers are not really suitable as sealants in the hot areas of engine cooling circuits. As soon as these elastomers come into contact with a coolant – usually a water/glycol mixture of over 100 degrees Celsius – some of their key properties for leak-tightness, such as elasticity and rebound resilience, deteriorate. ELASTOSIL® LR 3022/60 retains its rebound resilience permanently, which ensures consistently high leak-tightness in the seal groove. Furthermore, the overall property profile of cured ELASTOSIL® LR 3022/60 rubber remains virtually unchanged under long-term load.
In addition, the new cured silicone rubber exhibits very good low-temperature flexibility down to -45 degrees Celsius. With this combination of temperature and coolant resistance, ELASTOSIL® LR 3022/60 offers an alternative to organic elastomers.
Magnetizable: ELASTOSIL® R 781/80
ELASTOSIL® R 781/80, a solid silicone rubber filled with tiny magnetizable particles, is another innovation. The filler particles consist of magnetite, a ferrimagnetic material. The new solid silicone rubber thus lends itself to the manufacture of magnetizable molded parts and profiles that, after magnetization, act like weak permanent magnets. In addition, the magnetite particles make the silicone significantly more thermally conductive than standard silicones.
As a solid silicone rubber, ELASTOSIL® R 781/80 can be processed by conventional molding processes and extrusion. The cured rubber is extremely heat-resistant and will withstand temperatures ranging from -40 to +200 degrees Celsius with ease. After postcuring, the rubber grades are suitable for applications involving contact with food and meet the requirements of the German Federal Institute for Risk Assessment (BfR) and the US Food and Drug Administration (FDA).
The new silicone elastomer has a variety of applications. For example, it can be used to make magnetically adhering silicone products for magnetic panels. The magnetic adhesion is particularly strong if the substrate itself is magnetic. Furthermore, ELASTOSIL® R 781/80 can be detected by metal probes, even if only very low amounts of it are present in a compound. This opens up numerous applications in the food, pharmaceutical and medical-technology sectors.
The new solid silicone rubber also offers an elevated thermal conductivity which can be advantageous in baking molds, for example. Baking molds made from ELASTOSIL® R 781/80 will be hotter on the inside than conventional silicone molds, which makes for “extra crispy” baked goods.