• Design & Manufacturing
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• v.1 no.1
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• pp.17-21
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• 2007

In the manufacture and processing of large plastic materials, product quality is tested and verified through several techniques such as injection processing, residual stress through injection molding and shrinkage. With regards to the injection molding process, common problems such as inconsistent density is seen when different points of the product are discovered to have varying thickness levels. Sink marks in product are then evident. This occurs when there is poor molding conditions caused about by poor runner and packaging systems incorporated into the process. We designed the runner system which is possible balanced filling to cavities using CAE program $Moldflow^{TM}$ and then obtained optimal processing conditions by Taguchi's Robust Design technique.

• Design & Manufacturing
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• v.9 no.3
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• pp.24-28
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• 2015

Speaking in general terms the form injection process can be described as a new process-variant of already known structural foam molding technology which roots go back to the early sixties. The most limiting factors of already know foaming processes are large cell size and the lack of uniformity of these cells as well and the inability to foam all kinds of plastic materials. In this paper, Process Study on weight change in injection rate during foaming. Experimental conditions were set as the injection speed 50,150,300 and 450 mm/s. The experiments PA, PA+GF, PP, was confirmed that the weight increase to PP+TA.

• Design & Manufacturing
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• v.12 no.2
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• pp.57-62
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• 2018

In diabetics, daily blood glucose testing is generally required at home, and thus, performing blood collection several times a day using a blood line is essential. Blood collection in the home and in the hospital is a source of pain and is the second most common cause of infection. In blood collecting device generally consists of four major parts: inner-case, outer case, main shaft and triger, and the most import part among those for necessary functionality is the main shaft. Filling time and injection pressure, filling balance, strain-rate analysis of change based on availability of the product. The Moldflow of FEM simulation is used for the analysis of injection molding process. In this study, aims to create a technique for injection molding and manufacturing of a main shaft of a high-performance blood-collecting apparatus capable of automatically extracting a lancet to relieve pain through depth control of the lancet.

• Design & Manufacturing
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• v.2 no.2
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• pp.6-9
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• 2008

Injection molding is representative process of plastic production. Most of numerical analyses for injection molding have been based on the Hele Shaw's approximation: two-dimensional flow analysis. The present work covers numerical analyses of injection molding using three-dimensional solid elements. The accuracy of the analysis results has been verified through some numerical examples in comparison with the various conditions. In this study, moldflow software was used to analyze the cooling analysis. The results of cooling analysis and testing catapult were compared for plastic products.

• Design & Manufacturing
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• v.2 no.3
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• pp.10-15
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• 2008

Recently, mobile-phone with camera module has an absolute majority in the released mobile-phones. For this trend, High precision of the plastic subminiature barrel which is the core part is needed significantly because the camera module of mobile-phone must have high performance. Therefore, Structural stability of the injection mold for plastic subminiature barrel has to be guaranteed. In this paper, structural analysis of injection mold for plastic subminiature barrel is performed. Finally, the deformation trend and stability of injection mold core are analyzed.

• Design & Manufacturing
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• v.2 no.3
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• pp.1-5
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• 2008

Plastic parts are molded for the purpose of mass production in injection molding. Therefore designer is usually designing molds that has geometrically balanced hot runner lay-out for filling balance at cavities. Although, mold is manufactured with geometrically balanced runner lay-out, there are actually filling imbalances in cavities. These filling imbalances phenomenon are caused by complicated interaction between melt and mold. In this paper, filling imbalances for internal gear based on injection molding in hot-runner mold were investigated by CAE and injection molding experiences.

• Design & Manufacturing
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• v.13 no.1
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• pp.48-54
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• 2019

Analytical and experimental study were carried out in order to achieve simultaneous coating and injection molding of an automotive armrest. A mold was designed to be included one core and two cavities, which were composed of a substrate cavity and a coating cavity. The materials used were PC/ABS for substrate and 2-component Polyurethane for coating. The predicted flow patterns were in good agreement with experimental results in injection molding and in-mold coating. Based on analysis and experiment, it was found that the optimal processing conditions were packing pressure of 90MPa and holding time of 7sec.

• Design & Manufacturing
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• v.6 no.1
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• pp.12-17
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• 2012

In order to produce high-quality optical components, aspheric lenses have been widely applied in recent years. An aspheric lens consists of aspheric surfaces instead of spherical ones, which causes difficulty in the design process as well as the manufacturing procedure. Although injection molding is widely used to fabricate optical lenses owing to its high productivity, there remains lots of difficulty to determine appropriate mold design factors and injection molding parameters. In the injection molding fields, computer simulation has been effectively applied to analyze processes based on the shell analysis so far. Considering the geometry of optical lenses, a full-3d simulation based on solid elements has been reported as a reliable approach. The present work covers three-dimensional injection molding simulation and relevant deformation analysis of an injection molded plastic lens based on 3d solid elements. Numerical analyses have been applied to the injection molding processes of three aspheric lenses for an image sensing module of a mobile phone. The reliability of the proposed approach has been verified in comparison with the experimental results.

• Design & Manufacturing
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• v.8 no.2
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• pp.18-22
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• 2014

Two shot molding is one of the injection method which uses two materials or two color materials simultaneously in one mold. Two shot molding is good rate of productivity and economical because of no extra-progress necessary. The cowl grille is located in the bottom of wind shield glass and rolls as a passage of air inlet to inside of vehicle. It consists of body and seal. Firstly, the body is injected with PP. Next seal is extruded with EPDM and engineered and then assembled with body. These procedures lead high cost of production and the quality of part has problems. Therefore, it has effects on saving production cost and being a solution of the quality problems with the development of two shot molding cowl grille. It is guaranteed that two shot molding will be widely used in the vehicle parts industry afterwards.

• Design & Manufacturing
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• v.8 no.2
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• pp.1-6
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• 2014

The narrow-pitched connectors are of interest for small-scale devices such as smart phones because of theirs caling. We conducted an injection molding analysis and a warp analysis for 0.3mm and 0.5mm pitch FPC connectors. We obtained a volumetric shrinkage of 4.344%, a clamping force of 0.2529 tonne, a maximum injection pressure of 76.3 MPa as optimized molding conditions for the 0.3mm pitch FPC connector. We found that, compared with the traditional injection molding technique, the injection molding for narrow-pitched connectors comes with distinct features like low clamping force, high injection molding pressure, and narrow gate size. Adding to the optimization analysis, the deflection of 0.5mm pitch FPC connector was analyzed as well. A maximum deflection of 0.053mm was calculated, which the actual deflection of 0.062mm was compared to. The results deduced a relative error of 17%. We conclude that the deflection analysis along with the optimization analysis can be used as an effective tool to predict the behavior of narrow-pitch connectors although the relative error may need to improve.