Investigation of the Warpage of a High-Density Polyethylene Pallet by Plastic Injection Compression Molding: Part I—Numerical Approach

Abstract

Many challenges are associated with the injection compression molding process for producing a half-pallet (1320 mm × 1110 mm × 75 mm, length × width × height), which is butt-welded to another one for enhancing its strength. This pooled high-density polyethylene (HDPE) pallet is able to endure the impacts of a heavy load and a low ambient temperature. Reducing the warpage of a half-pallet is, therefore, essential for reducing the residual internal stress within the welded portions. An advanced Moldex3D package helps to detail the temperature distribution and warpage of a half-pallet. The pre-setting molding parameters from a mass-production factory produce half-pallets with worse flatness. In this investigation on using appropriate cooling water temperatures within the core and cavity plates of the mold, the numerical results show that the warpage of the top surface of the half-pallet was 11.549 mm, low warpage with respect to this large-scale pallet. Furthermore, the compression speed of 50–60 mm/s may have produced a low flatness of the half-pallet in this study.

Conformal Cooling Channel Design for Improving Temperature Distribution on the Cavity Surface in the Injection Molding Process

“…The main idea of this approach is to transform the response function into a suitable function and then optimize it. The overall desirability function was synthesized from the expectation functions of each response [54][55][56]. The object here maximizes the overall desirability function.…”

Taguchi–gray relational analysis of eccentricity and tilt of multilens module mount fabricated by injection compression molding

“…16,17 Past literature has analyzed and discussed the shrinkage and warping behavior of components produced by injection molding (IM) or ICM. 18,19 Compared to the more common IM process, ICM adds a compression stage, the benefits of which have been widely verified and acknowledged. 15,20,21 In terms of optimization methods, the Taguchi method and gray relational analysis (GRA) are often used for single or multiobjective optimization analysis.…”

“…Past literature has analyzed and discussed the shrinkage and warping behavior of components produced by injection molding (IM) or ICM 18,19 . Compared to the more common IM process, ICM adds a compression stage, the benefits of which have been widely verified and acknowledged 15,20,21 .…”