Extruding Growth in High Consistency Rubber Silicone

Shin-Etsu Silicones of America Inc., (SESA) a U.S. subsidiary of Shin-Etsu Chemical Co. Ltd., has launched its newest high consistency rubber (HCR) product line, the Sil-X-Shin Silicone Elastomers. The platinum, addition-cure series includes two distinct HCR extrusion versions: methyl-vinyl and phenyl silicone, specifically engineered for extruded tubing and profiles, and designed for use in healthcare, beverage, and architectural glazing applications.

Both series are available in a wide range of Shore A Hardness—from 40-80, and come in a 10:1 ratio of base compound to catalyst, which provides more overall mixing confidence. The advantage of having one universal catalyst that can be used with each base provides the benefit of flexibility. This also translates into reduced working capital and material logistics costs of stocking multiple products.

“We have intentionally engineered the formulations to have a longer working time between milling and extrusion,” said Steve Craig, SESA’s national business manager. “This increases material scheduling flexibility, as the product can actually be staged for nearly 24 hours during the processing gap.”

Sil-X-Shin’s methyl-vinyl extrusion grade series represents a second generation, optimized line of products with translucence and clarity. Notably, extruded tubing exhibits no bubble formation while curing in the oven, and it produces a smooth surface finish.

“Having processed every product in the series on production-scale equipment, I observed that the materials mill very easily and do not require a long time to freshen prior to adding catalyst. We’ve also processed successfully in both horizontal and vertical extrusion equipment,” noted Kendal Kozinski, HTV and TS&D supervisor for SESA.

Sil-X-Shin’s phenyl silicone has more specific applications, as it works exceptionally well in temperatures lower than -40 degrees Celsius with a -60 degrees Celsius minimum for optimal usage. Notably, this benefit provides better resistance to gamma sterilization and is ideally suited for applications such as pharmaceutical process tubing requiring low temperature resistance.

Specifically engineered for extrusion, both series’ platinum, addition-cure chemistries produce a tight surface finish with few residual byproducts. When properly cured, the finished products will resist taking a set, which can alter the dimensions of an extruded article. Additionally, both products are biocompatible and are currently being tested for USP Class VI compliance.

Shin-Etsu Silicones of America offers technical and capital resources to formulate solutions as a supplier of silicone materials to North America’s medical, automotive, electronics, aerospace, cosmetics, and manufacturing industries. The firm is based in Akron Ohio; its parent company, Shin-Etsu Chemical Co. Ltd., is headquartered in Japan.