Title: Numerical simulation and experimental study on physical mechanism in multiple component moulding

Authors: Chao-Tsai Huang; Che-Ping Lin; Shih-Po Sun; Shi-Chang Tseng; Rong-Yeu Chang

Addresses: Department of Chemical and Material Engineering, Tamkang University, No. 151, Yingzhuan Rd., Tamsui Dist., New Taipei City 25137, Taiwan ' R&D Department, CoreTech System (Moldex3D) Co., Ltd., 8F-2, No. 32, Taiyuan St., Chupei City, Hsinchu County 302, Taiwan ' R&D Department, CoreTech System (Moldex3D) Co., Ltd., 8F-2, No. 32, Taiyuan St., Chupei City, Hsinchu County 302, Taiwan ' National Yunlin University of Science and Technology, 123 University Road, Section 3, Douliou, Yunlin 64002, Taiwan ' CoreTech System (Moldex3D) Co., Ltd., 8F-2, No.32, Taiyuan St., Chupei City, Hsinchu County 302, Taiwan

Abstract: Multiple component moulding (MCM) is one of the great methods to fabricate the modern injection products. Due to many procedure combinations, it is very difficult to know the detailed process. Besides, because of its complicated nature and the unclear physical mechanism, using trial-and-error method cannot realise and manage the mechanism effectively. In this study, we will review various MCM technologies, including over-moulding, and co-injection moulding, and study these two applications in more details. Results show that the product geometries, process condition, and moulded materials will affect the product quality. The physical mechanism of warpage in a sequential over-moulded part is due to the unbalance between the volumetric shrinkage during filling/packing and the thermal unbalance from cooling. The warpage behaviour for co-injection moulding is more complicated because of the uncertain interface. However, one of the keys to manage the warpage is the control of the core penetration.

Keywords: multiple component moulding; MCM; over-moulding; co-injection moulding; warpage; numerical simulation; product geometries; process conditions; moulded materials; product quality; volumetric shrinkage; thermal unbalance; cooling.

DOI: 10.1504/IJMPT.2016.073627

International Journal of Materials and Product Technology, 2016 Vol.52 No.1/2, pp.118 - 142

Received: 21 Oct 2014
Accepted: 14 Jul 2015

Published online: 14 Dec 2015 *

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