scholarly journals Reducing the Sink Marks of a Crystalline Polymer Using External Gas-Assisted Injection Molding

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Shaofei Jiang ◽  
Taidong Li ◽  
Xinxin Xia ◽  
Xiang Peng ◽  
Jiquan Li
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Amorphous Polymer ◽  
Uniform Design ◽  
Quantitative Relationship ◽  
Crystalline Polymer ◽  
Process Conditions ◽  
Data Processing Method ◽  
Optimal Value ◽  
Sink Marks

External gas-assisted injection molding (EGAIM) has been used to reduce the sink marks of amorphous polymer products, but that of crystalline polymer products has not yet been reported. EGAIM of a crystalline polymer product was investigated in this study, and the influences of process parameters on the sink marks were discussed based on experiments. An isotactic polypropylene (iPP) product was fabricated by EGAIM under different process conditions. A uniform design was applied as an experimental design to investigate the influences of the process parameters on the sink marks. A regression equation was established to describe the quantitative relationship between the important parameters and sink marks in which a data-processing method was applied to determine the optimal value of Fα at significant level α to reduce the possibility of omission of some important parameters. The results show that EGAIM was effective in reducing the sink marks in these iPP products, and the most important parameters were the cooling time, gas pressure, and gas time. This study also provides the quantitative relationship between the important parameters and sink marks as reference for the research of EGAIM on crystalline polymer.

Influence of Injection Molding Process Parameters on Sink Marks of Injection Parts Based on Moldflow

2013 ◽  
Vol 347-350 ◽  
pp. 1163-1167
Author(s):  
Ling Bai ◽  
Hai Ying Zhang ◽  
Wen Liu
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Molding Process ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Sink Marks ◽  
Research Show

Moldflow software was used to obtain the best gate location and count. Influence of injection molding processing parameters on sink marks of injection-piece was studied based on orthogonal test. The effects of different process parameters were analyzed and better process parameters were obtained. Results of research show that decreasing melt temperature, mold temperature, the increasing injection time and packing pressure can effectively reduce the sink marks index.

Simulation and Analysis of Optimization Process Parameters for Multi-Cavity Injection Molding Parts Warpage by Genetic Algorithm Method

2011 ◽  
Vol 142 ◽  
pp. 54-57 ◽  
Author(s):  
Wen Jong Chen
Keyword(s):  
Genetic Algorithm ◽  
Finite Element Method ◽  
Finite Element ◽  
Injection Molding ◽  
Process Parameters ◽  
Orthogonal Array ◽  
Optimum Process ◽  
Process Conditions ◽  
Genetic Algorithm Method ◽  
Warpage Deformation

This study presents the warpage analysis for products through the combination of the genetic algorithm (GA) method and finite element method (FEM) in multi-cavity injection molding parts; it simulated and analyzed the warpage through controlling the conditions of various parameters in primary processes – filling, packing, and cooling. After 50 iterations of calculations. These results demonstrate that the maximum warpage of the products was 0.5052 mm for multi-cavity injection molding parts. In comparison with the orthogonal array, the maximum warpage could be reduced by approximately 7.24%. It is shown that the GA method can obtain the optimum process conditions for warpage deformation in multi-cavity injection molding parts.

Optimization of Process Parameters for Injection Molding Based on Taguchi Technique

2012 ◽  
Vol 538-541 ◽  
pp. 1170-1174
Author(s):  
Shi Jun Fu
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Orthogonal Design ◽  
Mold Temperature ◽  
Optimum Process ◽  
Process Conditions ◽  
Injection Time ◽  
Melt Temperature ◽  
Injection Process ◽  
Packing Pressure

In this paper, Taguchi and CAE technique are combined to study the influence of process conditions on the warpage of injection molding parts through twice orthogonal design experiments, and the injection process parameters are optimized according to the warpage. For the parameters selected, melt temperature and packing pressure have effects on the warpage of injection molding parts are highly significant, injection time is significant, other parameters have little effects. Within the range of experiments, the warpage decreased with the rise of the melt temperature and packing pressure. At last, the optimum process parameters of injection are that the mold temperature is 60°C, packing time is 10s, melt temperature is240°C, packing pressure is 115MPa and injection time is 0.4s.

scholarly journals The Improvement Effect and Mechanism of Longitudinal Ultrasonic Vibration on the Injection Molding Quality of a Polymeric Micro-Needle Array

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 151 ◽  
Author(s):  
Shan Gao ◽  
Zhongjun Qiu ◽  
Junhao Ouyang
Keyword(s):  
Injection Molding ◽  
Ultrasonic Vibration ◽  
Material Properties ◽  
Amorphous Polymer ◽  
Crystalline Polymer ◽  
Enhancement Effect ◽  
Industrial Processing ◽  
Filling Time ◽  
Improvement Effect ◽  
Enhancement Method

A polymeric micro-needle array with high quality has been fabricated using a longitudinal ultrasonic-assisted micro-injection molding (LUμIM) method. To realize the practicability and stability in actual industrial processing, this paper is aimed at studying the improvement mechanism of ultrasonic vibration on the molding quality. The melt-filling process in the micro-needle array cavity is simulated, and the improvement effect of ultrasonic vibration is discussed. The enhancement effect of ultrasonic vibration on material properties of polypropylene and polymethylmethacrylate parts are experimentally investigated. The results show that in the manufacturing of the micro-needle array part using LUμIM, the mold-filling quality is improved by the enhanced melt filling capability and pressure compensation effect, which are caused by the increased corner viscosity gradient, reduced the filling time and melt viscosity under ultrasonic vibration. Material properties of both the semi-crystalline polymer and amorphous polymer could be enhanced by the transformation of micromorphology. It is proved that for a semi-crystalline polymer, this novel method could be employed as a material properties enhancement method, and an optimal excitation voltage of ultrasonic vibration is obtained to achieve the best material properties.

Optimization of process parameters in plastic injection molding for minimizing the volumetric shrinkage and warpage using radial basis function (RBF) coupled with the k-fold cross validation technique

2019 ◽  
Vol 39 (5) ◽  
pp. 481-492 ◽  
Author(s):  
Behzad Shiroud Heidari ◽  
Amin Hedayati Moghaddam ◽  
Seyed Mohammad Davachi ◽  
Shadi Khamani ◽  
Afshar Alihosseini
Keyword(s):  
Injection Molding ◽  
Radial Basis Function ◽  
Process Parameters ◽  
Basis Function ◽  
Cross Validation ◽  
Volumetric Shrinkage ◽  
Process Conditions ◽  
Radial Basis ◽  
Validation Technique ◽  
Fold Cross Validation

Abstract In this study, a multi-objective design optimization method based on a radial basis function (RBF) model was applied to minimize the volumetric shrinkage and warpage of hip liners as an injection-molded biomedical part. The hip liners included an ultrahigh molecular weight polyethylene (UHMWPE) liner and UHMWPE reinforced with a nano-hydroxyapatite (nHA) liner. The shrinkage and warpage values of the hip liners were generated by simulation of the injection molding process using Autodesk Moldflow. The RBF model was used to build an approximate function relationship between the objectives and the process parameters. The process parameters, including mold temperature, melt temperature, injection time, packing time, packing pressure, coolant temperature, and type of liner, were surveyed to find the interaction effects of them on the shrinkage and warpage of the liners. The results indicated that the addition of nHA helps the liners to obtain more dimensional stability. The model was validated by the k-fold cross validation technique. Finally, the model revealed the optimal process conditions to achieve the minimized shrinkage and warpage simultaneously for various weights.

scholarly journals Temperature Profile in Rubber Injection Molding: Application of a Recently Developed Testing Method to Improve the Process Simulation and Calculation of Curing Kinetics

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 380
Author(s):  
Martin Traintinger ◽  
Roman Christopher Kerschbaumer ◽  
Bernhard Lechner ◽  
Walter Friesenbichler ◽  
Thomas Lucyshyn
Keyword(s):  
Injection Molding ◽  
Temperature Profile ◽  
Pressure Sensors ◽  
Simulation Software ◽  
Relative Degree ◽  
Actual State ◽  
Process Conditions ◽  
Inlet Temperature ◽  
Degree Of Cure ◽  
Mass Temperature

Injection molding of rubber compounds is an easily conducted yet sophisticated method for rubber processing. Simulation software is used to examine the optimal process conditions, identify failure scenarios, and save resources. Due to the complexity of the entire process, various aspects have to be considered in the numerical approach. This contribution focused on a comparison of process simulations with various definitions of the material’s inlet temperature, ranging from a stepwise increase, but constant temperature, to an exact axial mass temperature profile prior to injection. The latter was obtained with a specially designed, unique test stand consisting of a plasticizing cylinder equipped with pressure sensors, a throttle valve for pressure adjustments, and a measurement bar with thermocouples for the determination of the actual state of the mass temperature. For the verification of the theoretical calculations, practical experiments were conducted on a rubber injection molding machine equipped with the mold used in the simulation. The moldings, obtained at different vulcanization time, were characterized mechanically and the results were normalized to a relative degree of cure in order to enable comparison of the real process and the simulation. Considering the actual state of the mass temperature, the simulation showed an excellent correlation of the measured and calculated mass temperatures in the cold runner. Additionally, the relative degree of cure was closer to reality when the mass temperature profile after dosing was applied in the simulation.

scholarly journals Constant Temperature Approach for the Assessment of Injection Molding Parameter Influence on the Fatigue Behavior of Short Glass Fiber Reinforced Polyamide 6

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1569
Author(s):  
Selim Mrzljak ◽  
Alexander Delp ◽  
André Schlink ◽  
Jan-Christoph Zarges ◽  
Daniel Hülsbusch ◽  
...  
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Process Parameters ◽  
Fatigue Properties ◽  
Injection Molding Process ◽  
Molding Process ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Molding Parameter ◽  
Short Glass

Short glass fiber reinforced plastics (SGFRP) offer superior mechanical properties compared to polymers, while still also enabling almost unlimited geometric variations of components at large-scale production. PA6-GF30 represents one of the most used SGFRP for series components, but the impact of injection molding process parameters on the fatigue properties is still insufficiently investigated. In this study, various injection molding parameter configurations were investigated on PA6-GF30. To take the significant frequency dependency into account, tension–tension fatigue tests were performed using multiple amplitude tests, considering surface temperature-adjusted frequency to limit self-heating. The frequency adjustment leads to shorter testing durations as well as up to 20% higher lifetime under fatigue loading. A higher melt temperature and volume flow rate during injection molding lead to an increase of 16% regarding fatigue life. In situ Xray microtomography analysis revealed that this result was attributed to a stronger fiber alignment with larger fiber lengths in the flow direction. Using digital volume correlation, differences of up to 100% in local strain values at the same stress level for different injection molding process parameters were identified. The results prove that the injection molding parameters have a high influence on the fatigue properties and thus offer a large optimization potential, e.g., with regard to the component design.

scholarly journals Optimization of injection molding process for car fender in consideration of energy efficiency and product quality

2014 ◽  
Vol 1 (4) ◽  
pp. 256-265 ◽  
Author(s):  
Hong Seok Park ◽  
Trung Thanh Nguyen
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Injection Molding ◽  
Product Quality ◽  
Process Parameters ◽  
Optimization Problems ◽  
Computational Cost ◽  
Injection Molding Process ◽  
Molding Process ◽  
Nsga Ii

Abstract Energy efficiency is an essential consideration in sustainable manufacturing. This study presents the car fender-based injection molding process optimization that aims to resolve the trade-off between energy consumption and product quality at the same time in which process parameters are optimized variables. The process is specially optimized by applying response surface methodology and using nondominated sorting genetic algorithm II (NSGA II) in order to resolve multi-object optimization problems. To reduce computational cost and time in the problem-solving procedure, the combination of CAE-integration tools is employed. Based on the Pareto diagram, an appropriate solution is derived out to obtain optimal parameters. The optimization results show that the proposed approach can help effectively engineers in identifying optimal process parameters and achieving competitive advantages of energy consumption and product quality. In addition, the engineering analysis that can be employed to conduct holistic optimization of the injection molding process in order to increase energy efficiency and product quality was also mentioned in this paper.

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