By RTP Company
Design engineers choose TPEs for improved ergonomics, enhanced grip performance, improved aesthetics, and critical impact protection. Applications that benefit from TPE overmolds range from consumer goods to medical instruments to industrial tools and can include knobs, handles, gaskets, seals and grips.
Benefits of Overmolding
With improvements in TPE materials technology, overmolded part designs have become less dependent on mechanical interlocks to hold a TPE in place. Chemical bonds between TPE and rigid materials offer improved part integrity and longevity while eliminating the need for adhesives or surface pre-treatments. System performance can be further optimized by including both chemical and mechanical bonds in the part design. The net benefit is greatly expanded design freedom.
Chemical bonds in Overmolding:
Optimal Bonding Materials
Molders using multi-shot molding in combination with TPEs need to have a thorough understanding of bonding and how selection of both TPE and rigid substrates affect bond strength. RTP Company offers an expansive line of TPEs for bonding to specific engineering resins and assistance in selecting the ideal grades. The table below shows several examples:
* Checkmarks indicate combination exhibiting very good peel strength (15 pli or greater).
By offering multiple material options in combination with a variety of substrates, RTP Company’s TPE offering can meet a wide variety of applications where bonding to a rigid substrate is required. RTP Company can also offer modified rigid substrates to expand the material options to designers and engineers and make possible demanding applications that otherwise may not have been possible.
Insulet Corporation combined an RTP 6002 Series TPE and an RTP 300 Series polycarbonate (PC) in the housing of its award-winning OmniPod insulin management system. The TPE gasket created a water-tight seal for the housing. It also matched the precolored translucent white substrate perfectly so that the two components created the illusion of one part.
View the case study here.
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