A New Pair of Hard-soft Plastic Combination for Precision Manufacturing of Two Component Plastic Parts

摘要

Two component (2k) injection moulding is growing rapidly even in the field of precision micro moulding. Besides combining different material properties in the same product, two component moulding can eliminate many assembly steps in manufacturing process chain. One of the biggest technical challenges associated with 2k moulding is the unavailability of suitable material combinations which can meet the diverse requirements both from product and process point of view. This paper presents a new pair of commercial polymer materials (BASF Ultramid A3 EG 10 and Kraiburg TPE Thermolast K TC5PCZ) that fulfils the criteria for 2k moulding both from product and process considerations. Ultramid A3EG10 is PA6.6 thermoplastic with 50 % glass fibre reinforcement. Thermolast K TC5PCZ is a thermoplastic elastomer based on hydrated styrene block copolymers (TPE-S). By using this pair of materials, a demonstrator 2k micro part (Socket house for hearing aid) has been fabricated by the use of state-of-the-art 2k micro moulding machine. The tests performed on the demonstrator showed potential for the material pair to be used in high precision two component moulding applications. All the test procedures and results presented in this paper can be a valuable source of information for researchers and scientists who work with two component micro injection moulding.