Effects of Injection Molding Process Parameters on the Chemical Foaming Behavior of Polypropylene and Polystyrene

Chung, Chen Yuan; Hwang, Shyh Shin; Chen, Shia Chung; Lai, Ming Chien

doi:10.3390/polym13142331

Cited by 24 publications

(8 citation statements)

References 41 publications

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“…Meanwhile, bubbles defects that appear at a temperature of 195°C, due to the temperature setting above the recommended melting point (165°C) it is certain that bubbles will appear, although only slightly. These results are in accordance with statement [9], where the size of the cell density increases and the air is trapped in the melted material. Not only that, bubble defects appear when the injection temperature parameter is above the recommended burst point for plastic materials [10].…”

Section: Statistical Data Processing In Experiment-2supporting

confidence: 92%

Characterization of Differences in Cavity Positions Orientation in the Multi Cavity Plastic Molding Process on the Product Defects

Hartono¹,

Gumono²,

Wicaksono³

et al. 2022

Proceedings of the 2022 Annual Technology, Applied Science and Engineering Conference (ATASEC 2022)

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When performing the injection molding process, the influence of the set parameters such as injection time, injection pressure, and other parameters used will affect the mold result. The problem that arises when doing injection molding using multi-cavity molds is the appearance of product defects. The purpose of this study focuses on finding the parameters of the injection temperature, injection pressure, injection time and optimal interactions, and the position of the cavity orientation so that the product produced from multi-cavity molds is minimally flawed. The method used is to conduct experiments on the plastic molding process and compare the results of the different cavity positions in the vertical and horizontal positions. Experimental design chosen is DOE Factorial. The results obtained that there is an influence of injection temperature, injection pressure, injection time and cavity position on the number of defects. The recommended cavity position is to adjust the horizontal position right -left, because it produces minimal product defects. The smallest chance of defects occurs when the interaction of injection temperature is 210 C, injection pressure is 42 Bar, and injection time is 4.5 seconds.

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Section: Statistical Data Processing In Experiment-2supporting

confidence: 92%

Characterization of Differences in Cavity Positions Orientation in the Multi Cavity Plastic Molding Process on the Product Defects

Hartono¹,

Gumono²,

Wicaksono³

et al. 2022

Proceedings of the 2022 Annual Technology, Applied Science and Engineering Conference (ATASEC 2022)

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“…The cooling times of the wax patterns fabricated by the injection mold with and without coolant leakage were 22 s and 39 s, respectively. Note that a distinct defect of the molded wax pattern, named short shot (an incompletely filled mold cavity [ 18 , 19 ]), was observed when the mold had coolant leakage. In this study, injection molds were fabricated by a hexagonal scanning strategy because it provides a regular arrangement of pores inside the injection mold.…”

Section: Resultsmentioning

confidence: 99%

A Simple Method of Reducing Coolant Leakage for Direct Metal Printed Injection Mold with Conformal Cooling Channels Using General Process Parameters and Heat Treatment

Kuo

Qiu

2021

Materials

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Direct metal printing is a promising technique for manufacturing injection molds with complex conformal cooling channels from maraging steel powder, which is widely applied in automotive or aerospace industries. However, two major disadvantages of direct metal printing are the narrow process window and length of time consumed. The fabrication of high-density injection molds is frequently applied to prevent coolant leakage during the cooling stage. In this study, we propose a simple method of reducing coolant leakage for a direct-metal-printed injection mold with conformal cooling channels by combining injection mold fabrication with general process parameters, as well as solution and aging treatment (SAT). This study comprehensively investigates the microstructural evolution of the injection mold after SAT using field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. We found that the surface hardness of the injection mold was enhanced from HV 189 to HV 546 as the Ni-Mo precipitates increased from 12.8 to 18.5%. The size of the pores was reduced significantly due to iron oxide precipitates because the relative density of the injection mold increased from 99.18 to 99.72%. The total production time of the wax injection mold without coolant leakage during the cooling stage was only 62% that of the production time of the wax injection mold fabricated with high-density process parameters. A significant savings of up to 46% of the production cost of the injection mold was obtained.

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“…Furthermore, the equation governing the jetting behavior of the filling from the gate was discretized by a control volume-based, finite-volume method [ 22 ]. By using each of the commercialized software, including ANSYS Fluent [ 23 , 24 ], Moldflow [ 25 ], Open FOAM [ 26 ] and Moldex3D [ 10 , 27 , 28 , 29 , 30 ], one could analyze the multiple physical parameters of the output molding parts in relation to the operational parameters of the injection molding process. Notably, the experimental investigator could easily make a comparison between the simulation results and the real operational results in the laboratory.…”

Section: Introductionmentioning

confidence: 99%

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

Tsai

Liao

2022

Polymers

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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.

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Effects of Injection Molding Process Parameters on the Chemical Foaming Behavior of Polypropylene and Polystyrene

Cited by 24 publications

References 41 publications

Characterization of Differences in Cavity Positions Orientation in the Multi Cavity Plastic Molding Process on the Product Defects

Characterization of Differences in Cavity Positions Orientation in the Multi Cavity Plastic Molding Process on the Product Defects

A Simple Method of Reducing Coolant Leakage for Direct Metal Printed Injection Mold with Conformal Cooling Channels Using General Process Parameters and Heat Treatment

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

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