Is over-molding onto thermoplastic materials possible?

Question: In your prototyping experience, are you capable of over-molding onto thermoplastic materials? If so, what is the lowest melt temperature material that you have been successful without deforming the substrate (ABS, Nylon, Polycarbonate, etc.)? Additionally, do you find that a silicone primer is always necessary when over-molding?

Answer: In our experience, we have had success bonding silicone with certain thermoplastic materials. Since different types of materials require different temperature to work with, it would solely depend on that specific material. Over-molding silicone to plastics is limited to either using low temperature or faster cycle time. Plastic substrates would not deform under low temperature, but it will increase the cycle time during the over-molding process. In contrast, using high temperature can lower the cycle time, but can potentially damage the plastic substrate. Using silicone primer helps the over-molding process, while there are some other options available such as adhesive grade silicone and surface treatments.

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About Veasna

After interning for more than a year at Albright Technologies, Veasna gained experience in many aspects of silicone manufacturing including understanding of materials, mold making, and silicone molding. Veasna received a Bachelors of Science in Plastics Engineering from University of Massachusetts in Lowell in 2010, shortly after he accepted a full time position at Albright Technologies. In the spring of 2011, he received a Graduate Certificate in Plastics Design from UML. Veasna is mainly responsible for managing customer’s projects which begin from signed purchase orders to accepted and on-time part deliveries, he is also actively involved in research work on silicone bonding.