Observation and Evaluation of Scratch Damage Characteristics of Injection Molded, Rubber Toughened Poly(Methylmethacrylate)

2013 ◽  
Author(s):  
Jihun An ◽  
Byoung-Hyun Kang ◽  
Byoung-Ho Choi ◽  
Hyoung-Jun Kim
Keyword(s):  
Electron Microscopy ◽  
Injection Molding ◽  
Acrylonitrile Butadiene Styrene ◽  
Damage Mechanism ◽  
Damage Characteristics ◽  
Rubber Toughened ◽  
Rubber Particles ◽  
Injection Molded ◽  
Engineering Polymers ◽  
Scratch Tests

Poly(methylmethacrylate) (PMMA) is one of popular engineering polymers for many engineering applications such as glass substitutes, medical applications, electronic goods, optical fibers, laser disk optical media and so on. PMMA is a lightweight material with excellent optical properties and balanced mechanical properties. However, PMMA is commonly blended with various functional fillers, and rubber particles are one of them to improve the low impact toughness of unfilled PMMA comparing with other engineering polymers such as polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) copolymer and so on. PMMA is generally used to make exterior of a commercial product, so scratch characteristics of PMMA is very important in terms of the aesthetic point of view. In this paper, rubber toughened PMMA plates are prepared by injection molding, and static and progressive scratch tests are performed. Samples are prepared by various injection molding conditions, and two orientations (machine direction and transverse direction) of the injection molded plate are considered for scratch tests. Three scratch damage mechanism stages, i.e. mar/ploughing, whitening and cutting stages, are identified by observing the scratch damages and two critical loads to define the variation of scratch damage mechanisms are recorded to evaluate the scratch resistance of rubber toughened PMMA samples. Scratch damage characteristics are examined by various microscopy techniques such as optical microscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, optical profiler and so on. It is clearly observed that scratch damage characteristics of rubber toughened PMMA are changed sensitively for various test conditions due to rubber particles, so it can be known that the mold design should be carefully optimized to improve scratch characteristics of injection molded rubber toughened PMMA product.

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

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 ◽  
Packing Time

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.

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

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.

scholarly journals Are We Able to Print Components as Strong as Injection Molded?—Comparing the Properties of 3D Printed and Injection Molded Components Made from ABS Thermoplastic

2021 ◽  
Vol 11 (15) ◽  
pp. 6946
Author(s):  
Bartłomiej Podsiadły ◽  
Andrzej Skalski ◽  
Wiktor Rozpiórski ◽  
Marcin Słoma
Keyword(s):  
Tensile Strength ◽  
Injection Molding ◽  
Mechanical Strength ◽  
Cross Section ◽  
Fused Deposition Modeling ◽  
High Strength ◽  
Large Cross Section ◽  
Fused Deposition ◽  
Injection Molded ◽  
The Cross

In this paper, we are focusing on comparing results obtained for polymer elements manufactured with injection molding and additive manufacturing techniques. The analysis was performed for fused deposition modeling (FDM) and single screw injection molding with regards to the standards used in thermoplastics processing technology. We argue that the cross-section structure of the sample obtained via FDM is the key factor in the fabrication of high-strength components and that the dimensions of the samples have a strong influence on the mechanical properties. Large cross-section samples, 4 × 10 mm2, with three perimeter layers and 50% infill, have lower mechanical strength than injection molded reference samples—less than 60% of the strength. However, if we reduce the cross-section dimensions down to 2 × 4 mm2, the samples will be more durable, reaching up to 110% of the tensile strength observed for the injection molded samples. In the case of large cross-section samples, strength increases with the number of contour layers, leading to an increase of up to 97% of the tensile strength value for 11 perimeter layer samples. The mechanical strength of the printed components can also be improved by using lower values of the thickness of the deposited layers.

scholarly journals A Practical Numerical Approach to Characterizing Non-Linear Shrinkage and Optimizing Dimensional Deviation of Injection-Molded Small Module Plastic Gears

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2092
Author(s):  
Xiansong He ◽  
Wangqing Wu
Keyword(s):  
Injection Molding ◽  
High Speed ◽  
Numerical Approach ◽  
Linear Shrinkage ◽  
Influential Factor ◽  
Dimensional Deviation ◽  
Non Linear ◽  
Injection Molded ◽  
Plastic Gears ◽  
Circle Diameter

This paper was aimed at finding out the solution to the problem of insufficient dimensional accuracy caused by non-linear shrinkage deformation during injection molding of small module plastic gears. A practical numerical approach was proposed to characterize the non-linear shrinkage and optimize the dimensional deviation of the small module plastic gears. Specifically, Moldflow analysis was applied to visually simulate the shrinkage process of small module plastic gears during injection molding. A 3D shrinkage gear model was obtained and exported to compare with the designed gear model. After analyzing the non-linear shrinkage characteristics, the dimensional deviation of the addendum circle diameter and root circle diameter was investigated by orthogonal experiments. In the end, a high-speed cooling concept for the mold plate and the gear cavity was proposed to optimize the dimensional deviation. It was confirmed that the cooling rate is the most influential factor on the non-linear shrinkage of the injection-molded small module plastic gears. The dimensional deviation of the addendum circle diameter and the root circle diameter can be reduced by 22.79% and 22.99% with the proposed high-speed cooling concept, respectively.

scholarly journals Post-Processing Time Dependence of Shrinkage and Mechanical Properties of Injection-Molded Polypropylene

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 22
Author(s):  
Artur Kościuszko ◽  
Dawid Marciniak ◽  
Dariusz Sykutera
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Injection Molding ◽  
Accelerated Aging ◽  
Mold Temperature ◽  
Degree Of Crystallinity ◽  
Injection Mold ◽  
Secondary Crystallization ◽  
Scanning Calorimetry ◽  
Injection Molded

Dimensions of the injection-molded semi-crystalline materials (polymeric products) decrease with the time that elapses from their formation. The post-molding shrinkage is an effect of secondary crystallization; the increase in the degree of polymer crystallinity leads to an increase in stiffness and decrease in impact strength of the polymer material. The aim of this study was to assess the changes in the values of post-molding shrinkage of polypropylene produced by injection molding at two different temperatures of the mold (20 °C and 80 °C), and conditioned for 504 h at 23 °C. Subsequently, the samples were annealed for 24 h at 140 °C in order to conduct their accelerated aging. The results of shrinkage tests were related to the changes of mechanical properties that accompany the secondary crystallization. The degree of crystallinity of the conditioned samples was determined by means of density measurements and differential scanning calorimetry. It was found that the changes in the length of the moldings that took place after removal from the injection mold were accompanied by an increase of 20% in the modulus of elasticity, regardless of the conditions under which the samples were made. The differences in the shrinkage and mechanical properties of the samples resulting from mold temperature, as determined by tensile test, were removed by annealing. However, the samples made at two different injection mold temperature values still significantly differed in impact strength, the values of which were clearly higher for the annealed samples compared to the results determined for the samples immediately after the injection molding.

Mechanical Properties of Injection Molded Rubber Testing Samples

2015 ◽  
Vol 752-753 ◽  
pp. 308-311
Author(s):  
Adam Skrobak ◽  
Michal Stanek ◽  
David Manas ◽  
Martin Ovsik ◽  
Vojtech Senkerik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Standardized Testing ◽  
Rubber Compound ◽  
Testing Sample ◽  
Synthetic Rubber ◽  
Injection Molded

The aim of this article is to demonstrate and asses to what extent there is an impact on the mechanical properties of a standardized testing sample made of rubber compound based on synthetic rubber EPDM and produced by injection molding in comparison with a sample produced by classic preparation (cutting off a compression molded plate) according to the standard ISO 23529.

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.

Scratch tests on micro-structured polymer surfaces produced by injection molding and reaction processes

2011 ◽  
Vol 21 (6) ◽  
pp. 065031 ◽  
Author(s):  
Sascha Kuhn ◽  
August Burr ◽  
Michael Kübler ◽  
Matthias Deckert ◽  
Christoph Bleesen
Keyword(s):  
Injection Molding ◽  
Polymer Surfaces ◽  
Scratch Tests ◽  
Reaction Processes

Microstructure, Hardness, and Wear Resistance of Powder-Injection-Molded Products of Fe-Based Metamorphic Powders

2007 ◽  
Vol 26-28 ◽  
pp. 355-358
Author(s):  
Chang Kyu Kim ◽  
Chang Young Son ◽  
Dae Jin Ha ◽  
Tae Sik Yoon ◽  
Sung Hak Lee
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Injection Molding ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Thermally Stable ◽  
Austenitic Matrix ◽  
Amorphous Phases ◽  
Injection Molded

Powder injection molding (PIM) process was applied to Fe-based metamorphic alloy powders, and microstructure, hardness, and wear resistance of the PIM products were analyzed and compared with those of conventional PIM stainless steel products. When Fe-based metamorphic powders were injection-molded and then sintered at 1200 oC, completely densified products with almost no pores were obtained. They contained 34 vol.% of (Cr,Fe)2B borides dispersed in the austenitic matrix without amorphous phases. Since these (Cr,Fe)2B borides were very hard and thermally stable, hardness, and wear resistance of the PIM products of Fe-based metamorphic powders were twice as high as those of conventional PIM stainless steel products. Such property improvement suggested new applicability of the PIM products of Fe-based metamorphic powders to structures and parts requiring excellent mechanical properties.

Sign in / Sign up

Export Citation Format

Share Document