• 대한기계학회논문집A
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• 제20권3호
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• pp.765-774
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• 1996

Computer Integrated Manufacturing(CIM) requires models of manufacturing processes to be implemented on the computer. These models are typically used for determining optimal process control parameters or designing adaptive control systems. In spite of the progress made in the mechanistic modeling, however, empirical models derived from experimental data play a maior role in manufacturing process modeling. This paper describes the development of a meural metwork medel for injection molding. This paper describes the development of a nueral network model for injection molding process. The model uses the CAE analysis data based on Taguchi method. The developed model is, then, compared with the traditional polynomial regression model to assess the applicabilit in practice.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1630-1635
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• 2005

The microstructure of the parts made by the microcellular injection molding process influence properties, including impact strength, tensile strength and density of material. Microstructure of microcellular plastics is divided into core foaming region and solid skin region. Core foaming region is influenced by pressure drop rate, viscosity and cell coalescence. However, actual mechanism of the skin layers is not known despite its importance. The study on the skin layer is getting important because foaming rate of the plastics is determined by the thickness ratio of the skin layer. Especially in case of large molded part, control of the skin layer is needed because skin layer thickness is changed largely. Therefore it is necessary to study variation in skin layer thickness with processing parameters. In this paper, the influence of temperatures in the mold cavity on the skin layer s thickness was also addressed. In addition, the relationship between the temperature distributions across cavity of the mold with impact strength on parts made with the microcellular injection molding process was addressed. In addition, the method to predict the variation in skin layer thickness with mold temperature is discussed.

• 한국기계가공학회지
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• 제9권2호
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• pp.60-65
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• 2010

Injection molding process is one of the popular manufacturing methods to produce plastic parts with high efficiency and low cost. The tub-drum for drum type washer is made by an insert injection molding process with aluminum alloy insert of windmill type and has a big and complex structure consisted of many ribs to sustain the strength. In this paper, the volumetric shrinkages of rib part and bottom part surrounded by a windmill type insert are analyzed according to the vertical and circumferential direction of tub-drum. Volumetric shrinkage and its difference according to the height or radius of tub drum inform the designer to reduce the warpage of tub drum, and the optimal design of tub drum can be done from the those results. The change of volumetric shrinkage according to packing pressure is also analyzed. It is very important to analyze the volumetric shrinkage of tub drum because it generates the wearing phenomena at the rotating part connected to an aluminum alloy insert due to the warpage of tub drum.

• 한국분말재료학회지
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• 제23권1호
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• pp.26-32
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• 2016

Powder injection molding (PIM), which combines the advantages of powder metallurgy and plastic injection molding technologies, has become one of the most efficient methods for the net-shape production of both metal and ceramic components. In this work, plasma display panel glass bodies are prepared by the PIM process. After sintering, the hot isostatic pressing (HIP) process is adopted for improving the density and mechanical properties of the PIMed glass bodies. The mechanical and thermal behaviors of the prepared specimens are analyzed through bending tests and dilatometric analysis, respectively. After HIPing, the flexural strength of the prepared glass body reaches up to 92.17 MPa, which is 1.273 and 2.178 times that of the fused glass body and PIMed bodies, respectively. Moreover, a thermal expansion coefficient of $7.816{\times}10^{-6}/^{\circ}C$ is obtained, which coincides with that of the raw glass powder ($7.5-8.0{\times}10^{-6}/^{\circ}C$), indicating that the glass body is fully densified after the HIP process.

• Design & Manufacturing
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• 제10권2호
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• pp.50-54
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• 2016

In the semiconductor industry the final products were checked for several environments before sell the products. The burning test of memory and chip was implemented in reliability for all of parts. The memory and chip were developed to high density memory and high performance chip, so circuit design was also high integrated and the test bed was needed to be thin and fine pitch socket. LGA(Land Grid Array) IC socket with thin wall thickness was designed to satisfy this requirement. The LGA IC socket plastic part was manufacture by injection molding process, it was needed accuracy, stiffness and suit resin with high flowability. In this study, injection molding process analysis was executed for 2 and 4 cavities moldings with runner, gate and sprue. The warpage analysis was also implemented for further gate removal process. Through the analyses the total deformations of the moldings were predicted within maximum 0.05mm deformation. Finally in consideration of these results, 2 and 4 cavities molds were designed and made and tested in injection molding process.

• 한국기계가공학회지
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• 제18권11호
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• pp.1-8
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• 2019

In this study, we design the feed system and process conditions for a lamp garnish lens of an automobile. For this purpose, four design alternatives are presented and injection molding simulation analyses are performed. The optimal feed system is selected by considering the formability of the product and the cost of mold manufacture. The product formability is assessed by the weld line, warpage, sink mark and the maximum injection pressure, whereas the mold-making cost is estimated by the number of valve gates in the hot runner system. To improve the product formability, process conditions are optimized using an experimental design approach named one-factor-at-a-time. No weld line is generated as a result of the optimization. In addition, it is found the warpage and sink mark are reduced while the maximum injection pressure is increased, compared with those before the optimization.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.213-214
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• 2008

• Design & Manufacturing
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• 제15권1호
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• pp.48-56
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• 2021

The quality of products produced by injection molding process is greatly influenced by the process variables set on the injection molding machine during manufacturing. It is very difficult to predict the quality of injection molded product considering the stochastic nature of manufacturing process, because the process variables complexly affect the quality of the injection molded product. In the present study we predicted the quality of injection molded product using Artificial Neural Network (ANN) method specifically from Multiple Input Single Output (MISO) and Multiple Input Multiple Output (MIMO) perspectives. In order to train the ANN model a systematic plan was prepared based on a combination of orthogonal sampling and random sampling methods to represent various and robust patterns with small number of experiments. According to the plan the injection molding experiments were conducted to generate data that was separated into training, validation and test data groups to optimize the parameters of the ANN model and evaluate predicting performance of 4 structures (MISO1-2, MIMO1-2). Based on the predicting performance test, it was confirmed that as the number of output variables were decreased, the predicting performance was improved. The results indicated that it is effective to use single output model when we need to predict the quality of injection molded product with high accuracy.

• 한국산학기술학회논문지
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• 제11권4호
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• pp.1361-1366
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• 2010

본 논문은 매트릭스 수지로 PPS(Poly(phenylene sulfide))와 PP(Polypropylene)를 사용하였으며, 물리적 및 화학적 특성을 증대시키기 위해 주 첨가제로는 팽창 흑연, 합성 흑연과 보조 첨가제로는 유리 섬유, 카본 섬유, 카본 블랙을 사용하여 총 3가지의 복합소재를 제조하였다. 제조한 복합소재를 이용하여 사출 성형 및 평가 전에 CAE(Computer Aided Engineering)해석 프로그램을 통하여 해석을 하였으며, 사출성형을 통하여 사출조건(사출 압력, 가열시간, 금형온도 등)을 최적화하였다. 일반 사출성형의 경우 온도의 제한과 성형성의 한계가 있어 유동성이 낮은 복합소재의 경우 사출성형이 어렵기 때문에 이를 보완하기 위해 E-MOLD와 사출압축 기능을 함께 사용하여 복합소재의 성형성을 향상 시켰다. 사출 성형 된 각각의 최종 시편을 four point probe 장치를 사용하여 전기전도도를 측정/비교 하였고, 3가지 복합소재 중 PP/SG/CB를 혼합하여 제조한 복합소재가 성형성 및 전기전도도가 우수한 것을 확인하였다.

• 한국기계가공학회지
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• 제20권6호
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• pp.76-81
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• 2021

A plastic noise barrier is a structure installed to minimize noise, and it is composed of the main plate, sound-absorbing plate, and sound-absorbing material. Plastic noise barrier structures have several advantages compared to other products, such as light weight, anticorrosion, durability, easy assembly, rapid construction, and low costs. In this study, the main and sound-absorbing plates were manufactured through extrusion molding, and the sound-absorbing plate was finished with a press to improve the conventional injection molding. Extrusion molding dies and punch dies were designed, and a profile extrusion-molding system was developed. Thus, inexpensive and efficient sound-absorbing and main plates can be produced, and the noise barrier structure can be assembled rapidly. Additionally, a noise barrier structure with extended service life and excellent quality can be constructed by creating uniform free space to accommodate increased temperatures after assembly and installation.