Our Approach to Rubber Molding
Highly productive Injection Molding systems with waste saving devices represent a large percentage of our molding activity. In addition, we specialize in low waste transfer and flashless rubber molding. When appropriate, automation is designed to complement the chosen system, resulting in higher efficiency and reduced costs. Compression molding and rubber bonded to metal and plastic substrates are two additional specialties we offer.
This method is mostly used for larger parts and/or with very expensive compounds. This method utilizes less expensive tooling, but is not as precise as other methods of rubber molding. With compression molding, material is placed directly into the open cavity and then the parting lines are clamped and the part is formed.
This method is most often used for producing precision parts adhering to tight tolerances. We often incorporate hardened and self registering cavity inserts in our rubber molds to ensure perfect registration along with dimensional and flash control. With transfer molding material is “transferred” through sprues into the cavity while the parting lines are clamped and the part is formed.
Low Waste Molding
This method is a fine tuning of the transfer molding process which includes low waste features. The resulting vestige is only the sprue that feeds the cavity. This allows us to target economics and offer a savings to our customers.
This method of molding has been a growing part of our business. At Rahco, we mold flash free parts using the transfer, low waste method. These molds are always made with hardened stainless steel cavity inserts and run in special vacuum presses. We use this process to eliminate cryogenic or die trim finishing thereby reducing costs and keeping the parts free of contamination.
Many types of substrates including brass, aluminum, steel and plastic can be either mechanically or chemically bonded to rubber. Our chemical bonds can withstand the most demanding adhesion requirements.
Valve Gate Molding
ZERO WASTE! With this type of cold runner design, there is literally no residual waste. Although tooling is a bit more expensive, this system pays for itself for the right application.
Liquid Silicone Molding
Also known as LSR (Liquid Silicone Rubber). We use the most sophisticated molding system available to produce these types of Silicone parts. This type of molding system yields parts that are flash-free, no waste and leave minimum indication of gates. LSR injection technology is characterized by consistent quality and speed. This type of molding enables production in the field of high precision components, even with intricate component/part design, due to the tight tolerances the LSR is able to hold. Additionally, the process allows for the production of high quality components continuously with stable operations. The process is also scalable from prototype to high-volume production, allowing for molds with high cavitation or variably sized parts.