• Design & Manufacturing
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• 제13권4호
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• pp.34-39
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• 2019

In this paper, in order to improve the formability and quality of the injection molded parts in the molds for molding the motorcycle rear cowl injection molded parts with different volumes at the same time, the flow of the molded parts is changed through the injection molding CAE analysis by changing the gate position, runner size and position. It is to find the optimum gate position, the diameter of the runner and the position where the balance is equal. The molded article formed by the optimization resulted in the uniformity of the molten resin at the same time at the corner of the product, thereby maintaining the flow balance favorable for mass production at lower injection pressure.

• 폴리머
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• 제32권6호
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• pp.501-508
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• 2008

렌즈나 휴대폰 부품 같은 소형 플라스틱 부품들은 일반적으로 다수 캐비티 사출금형에서 성형된다. 이러한 다수 캐비티 금형에서의 사출성형은 캐비티간의 충전 불균형이 일어날 수 있다. 이러한 충전 불균형 현상은 제품의 치수 및 중량의 편차뿐 아니라 제품의 물리적 특성에도 영향을 미친다. 충전 불균형은 무엇보다도 기하학적으로 균형 잡히지 않은 delivery system의 설계에서 기인된다. 하지만 delivery system이 기하학적으로 균형 있게 설계가 되었다 하더라도 충전 불균형 현상은 여전히 발생된다. 이러한 현상은 런너 단면에서의 온도분포에 기인하며 사출성형 공정 중 사출속도에 크게 영향을 받는 것으로 본 연구에서 파악되었다. 즉 충전 불균형은 부적절한 사출 성형 공정에 의해 발생되며 성형 공정 조건 중 사출속도는 충전에 영향을 주는 매우 중요한 요소이다. 본 연구에서는 재료와 사출 속도에 따른 충전 불균형 현상을 실험과 CAE을 통하여 관찰하였다. 사출속도 변화에 따른 충전 불균형 때문에 시편의 치수 및 무게가 불균일함을 확인하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 추계학술발표대회 논문집
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• pp.61-63
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• 2001

Residual stress distribution in injection-molded short fiber composites was determined using layer-removal method. Polysterene with 3 vol% carbon fibers was injection-molded into the tensile specimen. With milling machine layer-removal process was conducted and the curvature data were acquired. Treuting and Read analysis which is assuming isotropic material, and White analysis considering anisotropy due to the fiber orientation were used to calculate residual stress of the flow direction through the thickness direction and compared with each other.

• 반도체디스플레이기술학회지
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• 제6권3호
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• pp.7-11
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• 2007

The design and manufacture of injection-molded parts with desired properties is a costly process dominated by empiricism, Including the repeated modification of actual tooling. The objective of this study is to obtain the good design of injection-molded polymeric parts using axiomatic design approach.

• Design & Manufacturing
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• 제17권4호
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• pp.72-78
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• 2023

Injection molding is a process widely used in various industries because of its high production speed and ease of mass production during the plastic manufacturing process, and the product is molded by injecting molten plastic into the mold at high speed and pressure. Since process conditions such as resin and mold temperature mutually affect the process and the quality of the molded product, it is difficult to accurately predict quality through mathematical or statistical methods. Recently, studies to predict the quality of injection molded products by applying artificial neural networks, which are known to be very useful for analyzing nonlinear types of problems, are actively underway. In this study, structural optimization of neural networks was conducted by applying multi-task learning techniques according to the characteristics of the input and output parameters of the artificial neural network. A structure reflecting the characteristics of each process step was applied to the input parameters, and a structure reflecting the quality characteristics of the injection molded part was applied to the output parameters using multi-tasking learning. Building an artificial neural network to predict the three qualities (mass, diameter, height) of injection-molded product under six process conditions (melt temperature, mold temperature, injection speed, packing pressure, pacing time, cooling time) and comparing its performance with the existing neural network, we observed enhancements in prediction accuracy for mass, diameter, and height by approximately 69.38%, 24.87%, and 39.87%, respectively.

• 한국산학기술학회논문지
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• 제9권1호
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• pp.165-169
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• 2008

사출 조건이 이성분계 고분자 블렌드의 형태학에 미치는 영향을 관찰하기 위해 폴리페닐렌옥사이드 (PPO)/폴리아마이드 6 (PA 6) 블렌드를 선정하였다. 두께가 3.2 mm이고 한 변의 길이가 15 cm인 정사각형의 평판 형태의 사출물을 여러 사출 조건에서 제조하고 각 위치별로 파단시편을 제조하여 형태학을 관찰하였다. 그 결과 수지가 스크류, 노즐 스프루 게이트를 지나 최종위치에 자리 잡을 때까지 복잡한 온도, 전단력과 신장력의 영향으로 복잡한 형태학을 가짐을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.431-436
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• 1986

The design and manufacture of injection molded polymeic parts with desired mechanical properties is a costly process dominated by empiricism, including the modification of actual tooling. This paper presents an interactive computer-based design system for injection molded plastic parts. This knowledge-based synthesis system provides a rational design strategy for injection molding and molded parts. It synergistically combines a rule-based expert system for hurestic knowledge with analytical process simulation programs. The theremomechanical properties of a molded part such as the effect of molecular orientation and weldline strength are predicted by the analysis programs; while the expert system interprets the analytical results from the process simulation, evaluates the design, and generates recommendations for optimal design alternatives. The heuristic knowledge of injection molding is formalized as production rules of the expert consultation system.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.176-179
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• 2009

Injection molding is one of the most general manufacturing processes of polymers. The deformation of final molded parts occurs because of the change of temperature and pressure during injection molding process. The deformation of injection molded parts depends on many operational conditions, such as, melt temperature, injection speed, mold temperature, packing pressure, and the structure of mold. In the present paper, injection molding experiments were performed to find the process conditions to affect the average shrinkage in thickness direction and the replication ratio of fine patterns on the surface for the final injection-molded LGP samples. As a results, in the cases of PC(Polycarbonate), when the melt temperature was under $285^{\circ}C$, both average shrinkage and replication ratios were mainly influenced by packing pressure. However, the replication ratio was more influenced by melt temperature than packing pressure for the cases of higher melt temperature.

• 한국기계가공학회지
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• 제11권3호
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• pp.92-97
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• 2012

Injection mold is a manufacturing process used to produce parts of complicated shape at a low cost. Many factors affect the quality of injection molded part during injection molding process. A study on the optimization of injection mold is progressed by using a simulation software like Moldflow. Filling, packing and cooling phases of injection molding processes are analyzed according to the mold design considering the shrinkage of molded part, the degree of filling rate and the wearing of a mold. Taguchi method is applied to analyze the significance of processing parameter and the dynamic characteristics according to the variation of processing parameters. From the results, the mold temperature and packing pressure influenced the shrinkage of injection molded part.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.58-64
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• 2004

The shrinkages of injection molded parts are different in molding operational conditions, resins and additives. The shrinkage of injection molded part for crystalline polymer, PBT (polybutylene terephthalate) has been studied for various operational conditions of injection molding and content of additives. Mica was used as a additive to PBT to examine the part shrinkage according to the mica content. The part shrinkages of mica contained PBT decreased as mica content increases. Higher injection temperature and injection pressure resulted in a lower shrinkage. As mold temperature increases the part shrinkage decreased. The part shrinkage of flow direction was less than that of the perpendicular direction to the flow for both pure and mica contained PBT. However the shrinkage difference between flow and perpendicular to flow directions decreased as mica content increased.