Feasibility Study of the Flatness of a Plastic Injection Molded Pallet by a Newly Proposed Sequential Valve Gate System

Abstract

The investigation of plastic pallet molding, assisted by a sequential valve gate system, has not yet been performed due to the limitations of the pallet scale. Furthermore, at present, the application of recycled plastics by chemical industries has become extremely popular around the world. This study aimed to determine pallet flatness experimentally and numerically using recycled polypropylene with a large-scale pallet. Short-shot testing on injection molding was performed to obtain short-shot samples for confirmation of the flow front during simulated filling. The real injected pallet profile, which was measured by an ATOS, was compared after confirmation to the numerical profile of the pallet. The pallet’s flatness was accurately compared to the real experimental and numerical results. By adjusting the temperature of the cooling channel within the cavity plate to 55 °C, the flatness of the pallet achieved by the newly proposed sequential valve gate-opening scheme was about 7 mm, which meets the height directional warpage standard determined by the pre-set sequential scheme. The numerical flatness is in line with existing flatness values for pallets. Furthermore, the proposed cooling temperature gives the highest yield in terms of pallet molding from the perspective of the stakeholders.

Mechanical Properties of Recycling Mixed Waste Plastic Predicted on Pallet Application Using Finite Element Analysis

“…it might be affected accelerating the destruction of forests and other environmental issues as a consequence of excessive harvesting of trees [10]. Some research has been conducted experiment on the alternative emerging recycling material for pallet application through the injection molding process as reported in [12], [13]. Therefore, the main objective of this research is to uncover the potential of mechanical properties obtained by the compression molding on pasta phase made of mixed plastic waste, then applied to pallet application by implementing the finite element analysis as an instrument to predict the design reliability.…”

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

“…Either in the injection molding process or in ICM, multiple physical effects on the molding parts due to operational parameters were analyzed using the following commercialized software: ANSYS Fluent [ 22 , 23 ], Moldflow [ 24 ], Open FOAM [ 25 ], and Moldex3D [ 13 , 26 , 27 , 28 , 29 , 30 ]. Numerical investigation was implemented using Moldex3D software.…”

Filling-Balance-Oriented Parameters for Multi-Cavity Molds in Polyvinyl Chloride Injection Molding

“…However, the ranges of the melt temperature and filling rate in PVC injection molding are limited due to PVC degradation [6]. Under the real settings of the machine specifications, simulations by molding flow software have been successfully implemented to derive molding parameters for practical operations [7][8][9][10][11]. To avoid PVC degradation during injection molding, simulations may also help to construct a successful set of parameters to enhance the molding efficiency by examining the temperature distribution of the cavity during the filling stage [12].…”

“…Filling imbalance can also lead the firstly filled cavity to an over-packing situation [7]. The short-shot technique by an empirical approach [10,11] can reveal filling imbalance. Based on the revealed results, the sizes of the runners and/or gates of the mold can be changed using machine tools via a traditional trial-and-error approach.…”