Liquid Silicone Rubber (LSR) injection molding makes up just 10% to 15% of U.S. medical or automotive applications that are also served by high-consistency silicone rubber (HCR), EPDM, latex, natural rubber, TPEs, flexible PVC, and even porcelain ceramic. Nonetheless, LSR molding is attracting growing interest (see Learn More), enough to prompt the formation of a new division dedicated to LSR by GW Plastics in Bethel, Vt.
This 58-year-old injection molding contract manufacturer, with sales approaching $100 million annually, specializes in close-tolerance parts and assemblies for healthcare and automotive markets. This is its first involvement in LSR. The new GW Silicones division will be located at its Royalton, Vt., technology and tooling campus and will provide extensive concept-to-production services for LSR and LSR-based multi-material prototype and production applications, says Larry Bell, v.p. of business development and marketing. The new division will make some of its own LSR molds as well.
“We usually serve a select group of Fortune 1000 companies with thermoplastic parts and assemblies. Now those clients say they require an elastomeric material that provides higher performance than a TPE. LSR materials fill that need,” says Bell. GW Plastics, which ranks itself among the world’s top precision molders, is looking to capitalize on the demand for both LSR and LSR/thermoplastic combinations.
GW Silicones will begin with the purchase of three LSR-configured injection machines from Engel, all of 100 tons or less. The first was installed last month. “To help understand and apply the technology, we have hired two LSR industry executives that have been in the market for years. One is competent in technical operations, while the other is well versed on the business-management side of LSR. This is how we will shorten our learning curve and get into this market quickly,” says Bell.
GW Plastics has been a precision molder since it was established in Bethel in 1955. In the mid- to late 1990s, the firm opened plants in Royalton, Vt.; San Antonio, Texas; and Tucson, Ariz. GW also established plants in Mexico and China in 2005. It operates approximately 150 hydraulic and electric presses from 7 to 500 tons, though many are in the 100- to 300-ton range.
The company has tool making at its Royalton and China facilities, where it builds two-thirds of its molds. “In the past, most of our molds were low-cavitation—one to four cavities—but now we are expanding rapidly into projects requiring eight, 16, and 32 cavities, owing to demand for ever higher volumes of tight-tolerance parts,” says Bell.
Much of GW’s success stems from a high level of standardization on technologies and operating procedures to achieve a high level of consistency at each facility. GW standardizes on press type, automation, and tooling.. “Every plant has the same layout,” Bell notes. GW also advocates the use of cavity-pressure control and process monitoring on many critical projects.