Development of an Integrated Melt Modulation System to Manipulate Cold-Runner Injection Molding Processing Parameters and Their Effects on Final Product Physical and Optical Properties

Packing processing parameters, including packing pressure and packing time, have significant impact on the internal molecular orientations, mechanical properties and optical performance of injection molded polymeric products. One of the limitations of cold-runner injection molding machines is the lack of real-time control of packing processing parameters during an injection molding cycle. As a result, a new melt modulation device has been developed and experimentally validated to control melt flow and manipulate processing parameters during cold-runner manufacturing. The use of the integrated melt modulation device has shown enhancement of physical properties and optical performance of injection molded polymeric products. Numerical simulations and experimental results of common thermoplastic optical polymers, such as PMMA, PC, and GPPS have been conducted and briefly demonstrated herein.

Warpage Measurement of a Micro Electrical Fan on Micro-Injection Molding

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.1651 ◽

2012 ◽

Vol 184-185 ◽

pp. 1651-1654

Author(s):

Jeou Long Lee ◽

Y. Lin ◽

Y.K. Shen

Keyword(s):

Injection Molding ◽

Injection Pressure ◽

Acrylonitrile Butadiene Styrene ◽

Mold Temperature ◽

Micro Injection Molding ◽

Optimum Result ◽

Suitable Material ◽

Packing Pressure ◽

Injection Molded ◽

This study characterizes warpage of a micro-injection molded micro electrical fan using the Michelson interference method. This study conducts experiments to analyze different polymers-polypropylene (PP), polyamide (PA), acrylonitrile-butadiene styrene (ABS), ABS+ polycarbonate (PC), and polyoxymethylene (POM)-process parameters, such as mold temperature, injection temperature, injection pressure, injection time, packing time, and packing pressure, for a micro electrical fan. To obtain the optimum result (minimum warpage), this study assesses the effect (warpage) of each material on micro-injection molding. PA plastic is the very suitable material for micro electrical fan with Michelson interference analysis on micro-injection molding.

Reduction in Defect Rate by Taguchi Method in Plastic Injection Molded Components

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.488-489.269 ◽

2012 ◽

Vol 488-489 ◽

pp. 269-273 ◽

Cited By ~ 2

Author(s):

G.S. Dangayach ◽

Deepak Kumar

Keyword(s):

Injection Molding ◽

Injection Pressure ◽

Processing Parameters ◽

Process Conditions ◽

Melt Temperature ◽

Defect Rate ◽

Packing Pressure ◽

Optimal Injection ◽

Packing Time ◽

Plastic Injection

In the present era, competition gets tougher; there is more pressure on manufacturing sectors to improve quality and customer satisfaction while decreasing cost and increasing productivity. These can be achieved by using modern quality management systems and process improvement techniques to reduce the process variability and driven waste within manufacturing process using effective application of statistical tools. Taguchi technique is well known technique to solve industrial problems. This technique is fast and can pinpoint the chief causes and variations. Plastic injection molding is suitable for mass production articles since complex geometries can be obtained in a single production step. The difficulty in setting optimal process conditions may cause defects in parts, such as shrinkage and warpage. In this paper, optimal injection molding conditions for minimum shrinkage were determined by the Taguchi design of experiment (DOE) approach. Polypropylene (PP) was injected in circular shaped specimens under various processing parameters: melt temperature, injection pressure, packing pressure and packing time. S/N ratios were utilized for determining the optimal set of parameters. According to the results, 2400 C of melt temperature, 75 MPa of injection pressure, 50 MPa of packing pressure and 15 sec. of packing time gave minimum shrinkage of 0.951% for PP. Statically the most significant parameter was melt temperature for the PP. Injection pressure had the least effect on the shrinkage. The defect rate was reduced from 14% to 3%.

Experimental And Numerical Studies of Shrinkage and Sink Marks On Injection Molded Polymer Gears

10.21203/rs.3.rs-421891/v1 ◽

2021 ◽

Author(s):

Bikram Solanki ◽

Hapreet Singh ◽

Tanuja Sheorey

Keyword(s):

Injection Molding ◽

Molding Process ◽

Melt Temperature ◽

Numerical Studies ◽

Packing Pressure ◽

Injection Molded ◽

Sink Marks ◽

Plastic Gears ◽

Abstract Injection molding is an efficient and most economical process employed for the mass production of plastic gears and helps to reduce the processing time and cost required to produce the desired geometry. However, significant process and product qualification of plastic gears face the shrinkage and sink marks issues during cooling and after ejection. In present work, the best gate locations and flow resistance analysis along with a polypropylene (PP) were carried out using Autodesk Moldflow Insight 2019.05. The numerical and experimental study was conducted to evaluate the effect of packing pressure, packing time, and melt temperature on diametric shrinkage, mass, and sink marks of PP gear. The results show that by increasing packing pressure and packing time, the diametric shrinkage decreased but mass increased. However, as the melt temperature increased the diametric shrinkage also increased but the mass decreased. The minimum diametric shrinkage of 0.562% was found in numerical analysis and 1.619% found in an experimental analysis at the same injection molding process parameters. Mostly, the sink marks were observed in the gear surface between hub and dedendum circle.

Effects of Injection Molding Screw Tips on Polymer Mixing

Periodica Polytechnica Mechanical Engineering ◽

10.3311/ppme.12183 ◽

2018 ◽

Vol 62 (3) ◽

pp. 241-246 ◽

Cited By ~ 2

Author(s):

Dániel Török ◽

József Gábor Kovács

Keyword(s):

Injection Molding ◽

Processing Parameters ◽

Raw Material ◽

Molding Machine ◽

Surface Color ◽

Melt Temperature ◽

Injection Molding Machine ◽

Aesthetic Appearance ◽

Molded Parts ◽

Injection Molded

In all fields of industry it is important to produce parts with good quality. Injection molded parts usually have to meet strict requirements technically and aesthetically. The aim of the measurements presented in our paper is to investigate the aesthetic appearance, such as surface color homogeneity, of injection molded parts. It depends on several factors, the raw material, the colorants, the injection molding machine and the processing parameters. In this project we investigated the effects of the injection molding machine on surface color homogeneity. We focused on injection molding screw tips and investigated five screw tips with different geometries. We produced flat specimens colored with a masterbatch and investigated color homogeneity. To evaluate the color homogeneity of the specimens, we used digital image analysis software developed by us. After that we measured the plastication rate and the melt temperature of the polymer melt because mixing depends on these factors. Our results showed that the screw tips (dynamic mixers) can improve surface color homogeneity but they cause an increase in melt temperature and a decrease in the plastication rate.

The simulation of the warpage rule of the thin-walled part of polypropylene composite based on the coupling effect of mold deformation and injection molding process

Science and Engineering of Composite Materials ◽

10.1515/secm-2015-0195 ◽

2018 ◽

Vol 25 (3) ◽

pp. 593-601 ◽

Cited By ~ 1

Author(s):

Jixiang Zhang ◽

Xiaoyi Yin ◽

Fengzhi Liu ◽

Pan Yang

Keyword(s):

Injection Molding ◽

Coupling Effect ◽

Mold Temperature ◽

Plastic Part ◽

Molding Process ◽

Melt Temperature ◽

Packing Pressure ◽

Thin Walled ◽

Abstract Aiming at the problem that a thin-walled plastic part easily produces warpage, an orthogonal experimental method was used for multiparameter coupling analysis, with mold structure parameters and injection molding process parameters considered synthetically. The plastic part deformation under different experiment schemes was comparatively studied, and the key factors affecting the plastic part warpage were analyzed. Then the injection molding process was optimized. The results showed that the important order of the influence factors for the plastic part warpage was packing pressure, packing time, cooling plan, mold temperature, and melt temperature. Among them, packing pressure was the most significant factor. The optimal injection molding process schemes reducing the plastic part warpage were melt temperature (260°C), mold temperature (60°C), packing pressure (150 MPa), packing time (2 s), and cooling plan 3. In this situation, the forming plate flatness was better.

Effect of Micro-Injection Molding Process Parameters for Warpage in Micro Plate Devices

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.898.265 ◽

2014 ◽

Vol 898 ◽

pp. 265-268

Author(s):

Duo Yang

Keyword(s):

Injection Molding ◽

Processing Parameters ◽

Processing Parameter ◽

Range Analysis ◽

Molding Process ◽

Factors Affecting ◽

Plastic Materials ◽

Best Parameter ◽

The injection molding process of micro plate devices requires several concerns in order to produce a quality output. In part of determining the best parameter settings, among other considerations that need to be taken are the types of plastic materials selected and the mold design. Molding parameters such as packing time, cooling temperature, molding and melting temperatures, packing and injection pressures are the most important factors affecting warpage of the micro plate part. These factors and their interactions were investigated in this research. The effects of processing parameter on the warpage of flat micro devices were analyzed according to the Taguchi method. In this paper, based on the range analysis, the parameter effective sequence was got, as well as the best processing parameters. The molding packing time has the strongest effects on the warpage, and the molding temperature is the secondary parameter. The cooling time has the lowest effects.

Dynamic Response Optimization for Cemented Carbide Injection Molding

Jurnal Teknologi ◽

10.11113/jt.v68.2993 ◽

2014 ◽

Vol 68 (4) ◽

Author(s):

Sri Yulis M. Amin ◽

Norhamidi Muhamad ◽

Khairur Rijal Jamaludin

Keyword(s):

Injection Molding ◽

Palm Stearin ◽

Processing Parameters ◽

Cemented Carbide ◽

Metal Injection Molding ◽

Molding Process ◽

Response Optimization ◽

Injection Molded ◽

Injection Temperature

The need to optimize the injection molding parameters for producing cemented carbide parts via Metal Injection Molding process is crucial to ensure the system’s robustness towards manufacturer and customer’s satisfactions. Defect free product with best density can be produced while reducing time and cost in manufacturing. In this work, the feedstock consisting of WC-Co powders, mixed with palm stearin and polyethylene binder system was injection molded to produce green parts. Several processing variables, namely powder loading, injection temperature, holding pressure and flowrate, were optimized towards the density of the green body, as the response factor. By considering humidity level at morning and evening conditions as the noise factor, the results show the optimum combination of injection molding parameters that produces best green density. The green part exhibited best density by following this optimum processing parameters, A2B3C1D1, that are flowrate at 20 ccm/s, powder loading at 63% vol., injection temperature at 140°C, and holding pressure at 1700 bar.

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.

The simulation of volume shrinkage for double-injection molding with PC and ABS

MATEC Web of Conferences ◽

10.1051/matecconf/201819201053 ◽

2018 ◽

Vol 192 ◽

pp. 01053

Author(s):

Pichai Leklong ◽

Wipoo sriseubsai

Keyword(s):

Injection Molding ◽

Weld Line ◽

Acrylonitrile Butadiene Styrene ◽

Volume Shrinkage ◽

Melt Temperature ◽

Double Injection ◽

Molded Part ◽

Packing Pressure ◽

Injection Molded ◽

Plastic Injection

The objective of this paper was to study and analyze the plastic injection molding parameters to reduce the volume shrinkage of double injection molded part. The specimen was molded with Acrylonitrile-butadiene-styrene (ABS) after Polycarbonate was molded as a half part. The weld line occurred at the haft of the molded part. The simulation with Moldex 3D R13 and the design of experiment with Taguchi method was used to perform the experiments and analyze the data to get the optimum of volume shrinkage. The results showed that melt temperature and packing pressure was significant to the volume shrinkage. When using low melt temperature and high packing pressure, the shrinkage was low and related to the thermal expansion of the material. It would be one of the parameters to the design of double injection molding.

Surface Homogeneity of Injection Molded Parts

Periodica Polytechnica Mechanical Engineering ◽

10.3311/ppme.12128 ◽

2018 ◽

Vol 62 (4) ◽

pp. 284-291 ◽

Cited By ~ 4

Author(s):

László Zsíros ◽

József Gábor Kovács

Keyword(s):

Injection Molding ◽

Evaluation Method ◽

Solid Phase ◽

Color Space ◽

Processing Parameters ◽

Mold Surface ◽

Molding Process ◽

Molded Parts ◽

Injection Molded

In this paper we are presenting a novel method for color inhomogeneity evaluation. We proved that this method has a higher than 95 % linear correlation coefficient if results are correlated with human visual evaluations.We applied this evaluation method to analyze the homogenization in the injection molding process, therefore we measured the homogenization properties of various solid phase masterbatches on injection molded parts. We tested the effects of the processing parameters of injection molding and analyzed various dynamic and static mixers as well. We have also measured the influence of the mold surface texture on the sensation of inhomogeneities on the part surface.We have carried out our tests on an injection grade ABS material using various masterbatches. The method was based on the digitization of the molded flat specimens. The images of these specimens were evaluated with an own developed formula using the CIELAB color space resulting high correlation with human visual inspections.