Influence of Processing Parameters on Residual Stress in Injection Molded Parts

2018 ◽  
pp. 476-484
Author(s):  
Przemyslaw Poszwa ◽  
Pawel Muszynski ◽  
Pawel Brzek ◽  
Krzysztof Mrozek
Keyword(s):  
Residual Stress ◽  
Processing Parameters ◽  
Molded Parts ◽  
Injection Molded

scholarly journals Effects of Injection Molding Screw Tips on Polymer Mixing

2018 ◽  
Vol 62 (3) ◽  
pp. 241-246 ◽  
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.

Numerical simulation and experimental validation of residual stress induced constrained shrinkage of injection molded parts

Polimery ◽  
2008 ◽  
Vol 53 (04) ◽  
pp. 304-310 ◽  
Author(s):  
TAHER AZDAST ◽  
AMIR HOSSEIN BEHRAVESH ◽  
KIUMARS MAZAHERI ◽  
MOHAMMAD MEHDI DARVISHI
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Experimental Validation ◽  
Molded Parts ◽  
Injection Molded

scholarly journals Influence of process parameters and runner geometry on shear heating effect

Mechanik ◽  
2018 ◽  
Vol 91 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Przemysław Poszwa ◽  
Paweł Brzęk ◽  
Marek Szostak
Keyword(s):  
Cross Section ◽  
Thermal Sensitivity ◽  
Processing Parameters ◽  
High Viscosity ◽  
Heating Effect ◽  
Influence Of Process Parameters ◽  
Molded Parts ◽  
Significant Temperature ◽  
Shear Heating ◽  
Injection Molded

Shear heating effect that occurs in melted polymers can cause serious quality problems with production of injection molded parts. The source of this effect is high viscosity of polymers and low thermal conductivity what leads to significant temperature gradients at the cross section of runners. In this work the influence of processing parameters on this phenomenon for difference runner diameters and lengths was presented for two polymers that have different thermal sensitivity.

Fiber Orientation in Injection-Compression Molded Short-Fiber-Reinforced Polypropylene Parts

2009 ◽  
Author(s):  
Han-Xiong Huang ◽  
Can Yang ◽  
Kun Li
Keyword(s):  
Fiber Orientation ◽  
Flow Direction ◽  
Processing Parameters ◽  
Short Fiber ◽  
Fiber Reinforced ◽  
Compression Force ◽  
Time Compression ◽  
Compression Time ◽  
Molded Parts ◽  
Injection Molded

Four processing parameters, including compression force, compression time, compression distance, and delay time, were investigated in terms of their effects on the fiber orientation in injection-compression molded (ICM) short-fiber-reinforced polypropylene parts. The results reveal that the fiber orientation pattern in ICM parts is different from that in conventional injection molded parts. Compression force plays an important role in determining the fiber orientation, whereas the effect of compression time can be neglected. Moreover, the fiber orientation changes obviously in the width direction, with most fibers arranging orderly in the flow direction at positions near the mold cavity wall.

scholarly journals Surface Homogeneity of Injection Molded Parts

2018 ◽  
Vol 62 (4) ◽  
pp. 284-291 ◽  
Author(s):  
László Zsíros ◽  
József Gábor Kovács
Keyword(s):  
Injection Molding ◽  
Evaluation Method ◽  
Solid Phase ◽  
Color Space ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
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.

Processing Optimization of Optical Lens in the Injection Molding

2013 ◽  
Vol 813 ◽  
pp. 161-164 ◽  
Author(s):  
Chao Ming Lin ◽  
Chih Kun Wang
Keyword(s):  
Residual Stress ◽  
Refractive Index ◽  
Residual Stresses ◽  
Processing Parameters ◽  
Processing Conditions ◽  
Fringe Order ◽  
Optimal Method ◽  
Optical Lens ◽  
Injection Molded ◽  
Processing Optimization

The processing conditions during the manufacturing have critical effects on the optical performances of the molded lenses including the refractive index, isochromatic fringe order, and the fringed pattern. The objective of this work is to investigate numerically some effects of the molding conditions on the residual stresses of injection molded lenses, and then to optimal the processing parameters for reducing the residual stresses using the Taguchi method. The results show the optimal method is able to improve the residual stress and to produce a good fringed pattern.

scholarly journals Surface strengthening of injection molded parts by applying a thermal insulation film

RSC Advances ◽  
2017 ◽  
Vol 7 (23) ◽  
pp. 14302-14308 ◽  
Author(s):  
Hwa Jin Oh ◽  
Young Seok Song
Keyword(s):  
Residual Stress ◽  
Thermal Insulation ◽  
Compressive Residual Stress ◽  
Surface Strengthening ◽  
Molded Parts ◽  
Injection Molded

The main objective of this study is to strengthen the surface of injection molded parts by building up the compressive residual stress at the surface of the product.

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