Effects of processing conditions on foaming behaviors of polyetherimide (PEI) and PEI/polypropylene blends in microcellular injection molding process

2014 ◽  
Vol 132 (7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Tao Liu ◽  
Yajie Lei ◽  
Zhenglun Chen ◽  
Xianzhong Wang ◽  
Shikai Luo
Keyword(s):  
Injection Molding ◽  
Injection Molding Process ◽  
Processing Conditions ◽  
Molding Process ◽  
Microcellular Injection Molding ◽  
Polypropylene Blends

An Experimental Evaluation of Vibration-Assisted Injection Molding During Manufacturing

1999 ◽  
Author(s):  
Alan M. Tom ◽  
Akihisa Kikuchi ◽  
John P. Coulter
Keyword(s):  
Experimental Study ◽  
Injection Molding ◽  
Scientific Explanation ◽  
Molecular Level ◽  
Injection Molding Process ◽  
Processing Conditions ◽  
Vibrational Motion ◽  
Current Investigation ◽  
Molding Process ◽  
Polymer Properties

Abstract The current investigation focused on contributing to the development of a novel injection molding process by attempting to understand the scientific relationship that exist between the applied vibrational parameters involved in this process and the effect it has on final product polymeric characterization. Although previous and current attempts at understanding the connection between applied oscillatory or vibrational motion to an injection molding process has shown positive quantitative advantages to final product properties, there still exists a void in the scientific explanation on a molecular level linking these effects. This experimental study, in particular, involved an evaluation on a range of processing conditions applied to Polystyrene and the effects it produced on resultant product quality and polymer properties. Optimal control and mechanical vibrational molding conditions were obtained for Polystyrene. As a result of this, optimal opportunities for initial commercial utilization of the technology can be proposed.

Injection Molding Process Windows Considering Two Conflicting Criteria: Simulation Results

2012 ◽  
Author(s):  
Alicia B. Rodríguez ◽  
Esmeralda Niño ◽  
Jose M. Castro ◽  
Marcelo Suarez ◽  
Mauricio Cabrera
Keyword(s):  
Injection Molding ◽  
Multiple Criteria ◽  
Process Window ◽  
Injection Molding Process ◽  
Processing Conditions ◽  
Molding Process ◽  
Multiple Criteria Optimization ◽  
Simulation Results ◽  
Main Ideas

In this work, two criteria in conflict are considered simultaneously to determine a process window for injection molding. The best compromises between the two criteria are identified through the application of multiple criteria optimization concepts. The aim with this work is to provide a formal and realistic strategy to set processing conditions in injection molding operations. In order to keep the main ideas manageable, the development of the strategy is constrained to two controllable variables in computer simulated parts.

Quantitative Study of Shrinkage and Warpage Behavior for Microcellular and Conventional Injection Molding

Materials ◽  
2005 ◽  
Author(s):  
Adam Kramschuster ◽  
Ryan Cavitt ◽  
Don Ermer ◽  
Chris Shen ◽  
Zhongbao Chen ◽  
...  
Keyword(s):  
Injection Molding ◽  
Hold Time ◽  
Fractional Factorial ◽  
Injection Molding Process ◽  
Molding Process ◽  
Injection Speed ◽  
Microcellular Injection Molding ◽  
Molded Parts ◽  
Injection Molded ◽  
Factorial Design Of Experiments

This research investigated the effects of processing conditions on the shrinkage and warpage (S&W) behavior of a box-shaped, polypropylene part using conventional, microcellular, and microcellular co-injection molding. Three sets of 26-1 fractional factorial design of experiments (DOE) were employed to perform the experiments and proper statistical theory was used to analyze the data. After the injection molding process reached steady state, molded samples were collected and measured using an optical coordinate measurement machine (OCMM), which had been evaluated using a proper repeatability and reproducibility (R&R) measurement study. By analyzing the statistically significant main and two-factor interaction effects, the results show that the supercritical fluid (SCF) content (nitrogen in this case, in terms of SCF dosage time) and the injection speed affect the S&W of microcellular injection and microcellular co-injection molded parts the most, whereas pack/hold pressure and pack/hold time have the most significant effect on the S&W of conventional injection molded parts. Also, this study quantitatively showed that, within the processing range studied, a reduction in the S&W could be achieved with the microcellular injection molding and micro- cellular co-injection molding processes.

scholarly journals High-Performance of a Thick-Walled Polyamide Composite Produced by Microcellular Injection Molding

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4199
Author(s):  
Dariusz Sykutera ◽  
Piotr Czyżewski ◽  
Piotr Szewczykowski
Keyword(s):  
Injection Molding ◽  
High Performance ◽  
Flow Direction ◽  
Cell Diameter ◽  
Injection Molding Process ◽  
Polyamide 66 ◽  
Molding Process ◽  
Sem Images ◽  
Microcellular Injection Molding ◽  
Sink Mark

Lightweight moldings obtained by microcellular injection molding (MIM) are of great significance for saving materials and reducing energy consumption. For thick-walled parts, the standard injection molding process brings some defects, including a sink mark, warpage, and high shrinkage. Polyamide 66 (PA66)/glass fiber (GF) thick-walled moldings were prepared by MuCell® technology. The influences of moldings thickness (6 and 8.4 mm) and applied nitrogen pressure (16 and 20 MPa) on the morphology and mechanical properties were studied. Finally, the microcellular structure with a small cell diameter of about 30 μm was confirmed. Despite a significant time reduction of the holding phase (to 0.3 s), high-performance PA66 GF30 foamed moldings without sink marks and warpage were obtained. The excellent strength properties and favorable impact resistance while reducing the weight of thick-walled moldings were achieved. The main reason for the good results of polyamide composite was the orientation of the fibers in the flow direction and the large number of small nitrogen cells in the core and transition zone. The structure gradient was analysed and confirmed with scanning electron microscopy (SEM) images, X-ray micro computed tomography (micro CT) and finite element method (FEM) simulation.

scholarly journals Using P(Pressure)-T(Temperature) Path to Control the Foaming Cell Sizes in Microcellular Injection Molding Process

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1843
Author(s):  
Shia-Chung Chen ◽  
Che-Wei Chang ◽  
Chia-Yen Tseng ◽  
En-Nien Shen ◽  
Ching-Te Feng
Keyword(s):  
Injection Molding ◽  
Release Time ◽  
Injection Molding Process ◽  
Molding Process ◽  
Foaming Agent ◽  
Microcellular Injection Molding ◽  
Cooling Speed ◽  
Successful Control ◽  
T Path ◽  
Temperature Path

Microcellular injection molding technology (MuCell) using supercritical fluid (SCF) as a foaming agent is one of the important green molding solutions for reducing the part weight, saving cycle time, and molding energy, and improving dimensional stability. In view of the environmental issues, the successful application of MuCell is becoming increasingly important. However, the molding process encounters difficulties including the sliver flow marks on the surface and unstable mechanical properties that are caused by the uneven foaming cell sizes within the part. In our previous studies, gas counter-pressure combined with dynamic molding temperature control was observed to be an effective and promising way of improving product quality. In this study, we extend this concept by incorporating additional parameters, such as gas pressure holding time and release time, and taking the mold cooling speed into account to form a P(pressure)-T(temperature) path in the SCF PT diagram. This study demonstrates the successful control of foaming cell size and uniformity in size distribution in microcellular injection molding of polystyrene (PS). A preliminary study in the molding of elastomer thermoplastic polyurethanes (TPU) using the P-T path also shows promising results.

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