Fundamentals and material development for thermoplastic elastomer (TPE) overmolding

This paper describes the use of TPE compounds for overmolding onto engineering thermoplastic resins. These TPE compounds have a wide range of hardness and are bondable to a wide spectrum of engineering thermoplastic and engineering thermoplastic elastomer substrates. The soft grades exhibit very smooth, tack-free, mar-resistant surfaces. The adhesion between the TPE and the substrate resists environmental changes such as hot air aging and water immersion. The adhesion data and other physical data, adhesion quantification methods, suggested processing conditions, and selected applications of these TPE overmolding compounds are also presented. Theories in TPE injection overmolding are discussed.