Numerical and Experimental Study on the Injection Moulding of a Thin-Wall Complex Part

Thin Wall ◽

Molding Process ◽

Complex Part ◽

Filling Time ◽

Wall Injection

The research presented in this paper involves numerical and experimental efforts to investigate the relative thin-wall injection molding process in order to obtain high dimensional quality complex parts. To better understand the effects of various processing parameters (the filling time, injection pressure, the melting temperature, the mold temperature) on the injection molding of a thin-wall complex part, the molding experiments are regenerated into the computer model using the Moldflow Plastics Insight (MPI) 6.1 software. The computer visualization of the filling phase allows accurate prediction of the location of the flow front, welding lines and air traps. Furthermore, in order to optimize the injection molding process, the effects of the geometry of the runner system on the filling and packing phases are also investigated. It is shown that computational modeling could be used to help the process and mold designer to produce accurate parts.

Experimental Characterization and Simulation of Thermoplastic Polymer Flow Hesitation in Thin-Wall Injection Molding Using Direct In-Mold Visualization Technique

Micromachines ◽

10.3390/mi11040428 ◽

2020 ◽

Vol 11 (4) ◽

pp. 428

Author(s):

Francesco Regi ◽

Patrick Guerrier ◽

Yang Zhang ◽

Guido Tosello

Keyword(s):

Injection Molding ◽

High Speed ◽

Pressure Sensors ◽

Injection Pressure ◽

Acrylonitrile Butadiene Styrene ◽

Thin Wall ◽

Molding Process ◽

Video Recordings ◽

Wall Injection

A special mold provided with a glass window was used in order to directly evaluate the flow progression during the filling phase of the injection molding process in a thin-wall cavity and to validate the simulation of the process with particular focus on the hesitation effect. The flow of the polymer was recorded at 500 frames per second using a high-speed camera (HSC). Two unfilled thermoplastic polymers, acrylonitrile butadiene styrene (ABS), and polypropylene (PP), were used to fill two different 50 mm × 18 mm staircase geometry cavities, which were specifically designed to evaluate the hesitation effect with thicknesses of 1500, 1250, 1000, 750, 500 µm (cavity insert no. 1) and 1500, 1200, 900, 600, 300 µm (cavity insert no. 2). In addition to the video recordings, the simulations were validated using the timings and the data obtained by three pressure sensors and two thermocouples located in the cavity. For each injection cycle recorded on camera the machine data were collected to carefully implement the correct boundary conditions in the simulations. The analysis of the video recordings highlighted that flow progression and hesitation were mainly influenced not only by the thickness, but also by the velocity and the material type. The simulation results were in relatively good agreement with the experiments in terms of flow pattern and progression. Filling times were predicted with an average relative error deviation of 2.5% throughout all the section thicknesses of the cavity. Lower accuracies in terms of both filling times and injection pressure were observed at increasingly thinner sections.

The Feasibility of an Internal Gas-Assisted Heating Method for Improving the Melt Filling Ability of Polyamide 6 Thermoplastic Composites in a Thin Wall Injection Molding Process

Polymers ◽

10.3390/polym13071004 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1004 ◽

Author(s):

Thanh Trung Do ◽

Tran Minh The Uyen ◽

Pham Son Minh

Keyword(s):

Injection Molding ◽

Heating Rate ◽

Temperature Control ◽

Cavity Surface ◽

Heating Process ◽

Thin Wall ◽

Molding Process ◽

Filling Ability ◽

Wall Injection

In thin wall injection molding, the filling of plastic material into the cavity will be restricted by the frozen layer due to the quick cooling of the hot melt when it contacts with the lower temperature surface of the cavity. This problem is heightened in composite material, which has a higher viscosity than pure plastic. In this paper, to reduce the frozen layer as well as improve the filling ability of polyamide 6 reinforced with 30 wt.% glass fiber (PA6/GF30%) in the thin wall injection molding process, a preheating step with the internal gas heating method was applied to heat the cavity surface to a high temperature, and then, the filling step was commenced. In this study, the filling ability of PA6/GF30% was studied with a melt flow thickness varying from 0.1 to 0.5 mm. To improve the filling ability, the mold temperature control technique was applied. In this study, an internal gas-assisted mold temperature control (In-GMTC) using different levels of mold insert thickness and gas temperatures to achieve rapid mold surface temperature control was established. The heating process was observed using an infrared camera and estimated by the temperature distribution and the heating rate. Then, the In-GMTC was employed to produce a thin product by an injection molding process with the In-GMTC system. The simulation results show that with agas temperature of 300 °C, the cavity surface could be heated under a heating rate that varied from 23.5 to 24.5 °C/s in the first 2 s. Then, the heating rate decreased. After the heating process was completed, the cavity temperature was varied from 83.8 to about 164.5 °C. In-GMTC was also used for the injection molding process with a part thickness that varied from 0.1 to 0.5 mm. The results show that with In-GMTC, the filling ability of composite material clearly increased from 2.8 to 18.6 mm with a flow thickness of 0.1 mm.

Optimization of the Injection Molding Process Parameters Based on Moldflow and Orthogonal Experiment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.561.239 ◽

2013 ◽

Vol 561 ◽

pp. 239-243 ◽

Author(s):

Yong Nie ◽

Hui Min Zhang ◽

Jia Teng Niu

Keyword(s):

Injection Molding ◽

Orthogonal Experiment ◽

Mold Temperature ◽

Processing Parameters ◽

Influential Factors ◽

Range Analysis ◽

Molding Process ◽

Melt Temperature ◽

Plastic Parts

This article is using Moldflow analysis and orthogonal experimental method during the whole experiment. The injection molding process of motor cover is simulated under various technological conditions.After forming the maximum amount of warpage of plastic parts for evaluation.According to the range analysis of the comprehensive goal, the extent of the overall influence to the processing parameters, such as gate location, melt temperature, mold temperature and holding pressure is clarified.Through analyzing the diagrams of influential factors resulted from the simulation result,the optimized process parameter scheme is obtained and further verified by simulation.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.347-350.1163 ◽

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 ◽

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.

Optimization and Design for Parameter in Injection Molding Technology of Cell Shell of Polypropylene

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.537 ◽

2011 ◽

Vol 189-193 ◽

pp. 537-540

Author(s):

Jia Min Zhang ◽

Ming Yi Zhu ◽

Zhao Xun Lian ◽

Rong Zhu

Keyword(s):

Injection Molding ◽

Injection Pressure ◽

Mold Temperature ◽

Technological Parameters ◽

Molding Process ◽

Melt Temperature ◽

Injection Speed ◽

Technical Parameters ◽

High Degree

The use of L27 (35) orthogonal to the battery shell injection molding process is optimized. The main factors of technical parameters were determined mould temperature, melt temperature, the speed of injection, injection pressure, cooling time.On the basis of actual production, to determine the factors values of different process parameters.Combination of scrapped products in key (reduction and a high degree of tolerance deflated) tests were selected in the process parameters within the scope of the assessment. Various factors impact on the product of the total height followed by cooling time, mold temperature, melt temperature, injection pressure, injection speed from strong to weak .The best products technological parameters were determined.Good results were obtained for production.

Injection Molding Process Parameter Optimization for Warpage Minimization Based on Uniform Design of Experiment

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.37-38.570 ◽

2010 ◽

Vol 37-38 ◽

pp. 570-575 ◽

Author(s):

Bao Shou Sun ◽

Zhe Chen ◽

Bo Qin Gu ◽

Xiao Diao Huang

Keyword(s):

Injection Molding ◽

Design Of Experiment ◽

Simulation Analysis ◽

Uniform Design ◽

Mold Temperature ◽

Optimization Method ◽

Processing Parameters ◽

Molding Process ◽

Melt Temperature

To optimize injection molding warpage, this paper applies the uniform design of experiment method to search for the optimal injection molding processing parameters. The warpage. simulation analysis is accomplished by emplying Moldflow software. The melt temperature, mold temperature, injection time and packing pressure are regarded as processing parameters, and processing parameters are optimized through establishing a regression equation, and the optimization result and influence factors are analyzed. The results show that uniform design of experiment can reduce number of experiments used effectively and the quality of the product is greatly improved by the optimization method.

Automotive Interior Parts Molding Process Simulation and Parameter Optimization

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.734-737.2725 ◽

2013 ◽

Vol 734-737 ◽

pp. 2725-2729

Author(s):

Yin Wu Tan ◽

You Min Wang ◽

Ge Zhou ◽

Xiao Yang Du

Keyword(s):

Injection Molding ◽

Orthogonal Experiment ◽

Injection Pressure ◽

Mold Temperature ◽

Molding Process ◽

Interior Decoration ◽

Melt Temperature ◽

Influence Of Process Parameters ◽

Sink Mark

By the use of UG software，the solid model of the interior decoration board inside the automobile door was created and the molding behavior of the plastic product was simulated and analysis in the virtue of Moldflow．Based on the analysis of the effect of the mould parameter on the molding behavior ,the best gate location was achieved.We designed the L9(33) orthogonal experiment table of the parts injection molding,selected the mold temperature, melt temperature, injection pressure as the factores .Sink mark index, volume shrinkage, maximumwarping deformation and cavity residual stress are determined as the parts quality evaluation. We completed the orthogonal experiment and the range analyses of the results. We analyzed the influence of process parameters on evaluation of every optimal direction,developed evaluation for comprehensive quality of parts. Finally, we get the table showing the tendency on the assessment of the quality index influenced by various factors, which provides a foundation for the approaching research on the parameters of the injection molding process.

Processability Testing of Injection Molding Rubber Compounds

Rubber Chemistry and Technology ◽

10.5254/1.3536037 ◽

1984 ◽

Vol 57 (4) ◽

pp. 826-842 ◽

Cited By ~ 5

Author(s):

John A. Sezna ◽

P. J. DiMauro

Keyword(s):

Injection Molding ◽

Injection Pressure ◽

Mold Temperature ◽

Capillary Rheometer ◽

Excellent Correlation ◽

Molding Process ◽

Rubber Compounds ◽

Using Data ◽

And Control

Abstract A simple model of the injection molding process has been constructed using data from a capillary rheometer (MPT) and the Oscillating Disk Rheometer (ODR). For an NR and an SBR compound, the model had an excellent correlation with injection molding trials. The model successfully predicted the effects of adjusting injection pressure, mold temperature, and barrel temperature on injection times and scorch conditions. Such a model enables an injection molder to predict the effect of adjusting molding conditions, optimize his process for a given mold and compound, and control processability of his compounds batch-to-batch.

Study on External Gas-Assisted Mold Temperature Control for Improving the Melt Flow Length of Thin Rib Products in the Injection Molding Process

Advances in Polymer Technology ◽

10.1155/2019/5973403 ◽

2019 ◽

Vol 2019 ◽

pp. 1-17 ◽

Cited By ~ 5

Author(s):

Phan The Nhan ◽

Thanh Trung Do ◽

Tran Anh Son ◽

Pham Son Minh

Keyword(s):

Injection Molding ◽

Temperature Control ◽

High Efficiency ◽

Mold Temperature ◽

Thin Wall ◽

Mold Surface ◽

Melt Flow ◽

Molding Process ◽

Flow Length

In the injection molding process, mold temperature control is one of the most efficient methods for improving product quality. In this research, an external gas-assisted mold temperature control (Ex-GMTC) with gas temperature variation from 200°C to 400°C was applied to thin wall injection molding at melt thicknesses from 0.2 to 0.6 mm. The melt flow length was evaluated through the application of this system to the mold of a thin rib product. The results show that the heating process achieves high efficiency in the initial 20 s, with a maximum heating rate of 6.4°C/s. In this case, the mold surface reached 158.4°C. By applying Ex-GMTC to a 0.2 mm flow thickness, the flow length increased from 37.85 to 41.32 mm with polypropylene (PP) material and from 14.54 to 15.8 mm with acrylonitrile butadiene styrene (ABS) material. With the thin rib mold and use of Ex-GMTC, the mold temperature varied from 112.0°C to 140.8°C and the thin rib height reached 7.0 mm.

Numerical Simulation of Shrinkage in the Microinjection Molding of Multi-Microparts Produced in one Mold

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.221.649 ◽

2011 ◽

Vol 221 ◽

pp. 649-656 ◽

Author(s):

Jian Wang ◽

Wei Min Yang

Keyword(s):

Numerical Simulation ◽

Injection Molding ◽

Plastic Material ◽

Control Volume ◽

Injection Pressure ◽

Mold Temperature ◽

Processing Parameters ◽

Melt Temperature ◽

Microinjection Molding

The aim of this paper is to verify the reliability of numerical results obtained by using MPI (Moldflow Plastic Insight) for predicting the shrinkage of multi-microparts produced in one mold in microinjection molding. 3D numerical simulation (control volume finite element method) was employed. Pure and 10-20 % GRF (glass fiber reinforced) POM materials were used for the plastic material. The injection molding process was used for different parameters (mold temperature, melt temperature and injection pressure). A DOE (Design of Experiments) technique was then used to plan the numerical simulation activity of the injection molding phase. Among injection processing parameters (mold temperature, melt temperature and injection pressure), the results showed that the mold temperature is the most important factor to affect the shrinkage of multi-microparts significantly for processing parameters. The results also indicated that the processing is very well for micro-injection molding by numerical simulation. In addition, properties of polymer composites with added fillers were systematically studied. Numerical simulation results showed that the numerical resulting composites with 10–20 wt% glass particles exhibited significant improvement in shrinkage, and showed good agreement with experimental results.