• Fibers and Polymers
• /
• 제4권2호
• /
• pp.89-96
• /
• 2003

A vertebral cage is a hollow medical device which is used in spine forgery. By implanting the cage into the spine column, it is possible to restore disc and relieve pressure on the nerve roots. Most cages have been made of titanium alloys but they detract the biocompatibility. Currently PEEK (polyether ether ketone) if applied to various implants because it has good properties like heat resistance, chemical resistance, strength, and especially biocompatibility. A new shape of vertebral cage is designed and injection molding of PEEK is considered for production. Before injection molding of the cage, it is needed to evaluate process conditions and properties of the final product. Variables affecting the shrinkage of the cage are considered, e.g., injection time, packing pressure, mold temperature, and melt temperature. By using the numerical simula-tion program, MOLDFLOW, several cases are studied. Data files obtained by MOLDFLOW analysis are used for stress anal-ysis with ABAQUS, and shrinkage and residual stress fields are predicted. With these results, optimum process conditions are determined.

• Journal of Advanced Marine Engineering and Technology
• /
• 제28권6호
• /
• pp.931-937
• /
• 2004

Simultaneous filling is a goal in plastic injection mold that has multi cavities. The moldings which have not been filled at the same time have undesired faults such as dimension inaccuracy, residual stress, law mechanical strength, etc. The best way to simultaneous fill is to be injected in a geometrically balanced runner system. In a general processing, however, in balanced runner system mold, filling imbalance would be observed in cavities. These phenomena result from molten polymer's characteristics and circumstances in balanced runner. In this study, the degree of filling imbalance (DFI) was defined for showing rate of filling imbalance in geometrically balanced injection mold that has 8 cavities. Before the main experiment, an injection molding simulation was conducted to know a pattern of filling imbalance with Moldflow software. There were somewhat differences between results of experiment and simulation about the filling imbalance. The reason for the difference was that the software have not concerned about a situation in a real flow channel. It was also investigated how the injection speed affected on filling imbalance in the experiment.

• 대한기계학회논문집A
• /
• 제27권4호
• /
• pp.507-514
• /
• 2003

Most of CAE analyses for injection molding have been based on the Mele Shaw's approximation: two-dimensional flow analysis. in some cases, that approximation causes significant errors due to loss of the geometrical information as well as simplification of the flow characteristics in the thickness direction. Although injection molding analysis software using three-dimensional solid elements has been developed recently, such as Moldflow Flow3D, it does not contain a deformation analysis function yet. The present work covers three-dimensional deformation analysis or injection molded plastic parts using solid elements. A numerical scheme for deformation analysis has bun proposed from the results of injection molding analysis using Moldflow Flow3D. The accuracy of the proposed approach has been verified through a numerical analysis of rectangular plates with various thicknesses in comparison with the classical shell-based approach. In addition, the reliability of the approach has also been proved through an industrial example. an optical plastic lens, in comparison of real experiments.

• Design & Manufacturing
• /
• 제12권2호
• /
• pp.22-26
• /
• 2018

In the automotive industry these days, plastic parts have been developed and replaced with plastic parts by maintaining the same function of existing press parts for a variety of reasons. Injection molding plastic parts are subject to molding defects due to various factors, among which the sink marks usually occur in the areas where bosses and ribs are installed. In this study, we analyzed the influence of various factors on the occurrence of sink marks by using the flow analysis of the forming analysis program(Moldflow analysis) using the rib model with the T-shape. Tests have shown that the greatest influence on the sink mark of cosmetic products is the thickness and pressure of the ribs, and the thickness of the basic moulding thickness of the product increases. However, it was considered that the resin temperature and the mold temperature do not greatly affect the occurrence of the sink mark.

• 한국산학기술학회논문지
• /
• 제7권6호
• /
• pp.1040-1046
• /
• 2006

본 논문에서는 다양한 곡률반경의 연속에 의하여 살 두께 차가 큰 사출성형품이 불균일한 수축에 의한 변형 발생에 대하여 연구하였다. SAN 및 PMMA 재질의 Jar에 대한 균일냉각구조와 최적성형조건을 CAE 해석에서 구하여 금형설계에 적용하고자 사출성형의 중요인자인 사출압력, 수지온도, 금형온도, 냉각조건 등을 Moldflow 프로그램에서 사출압력, 수지온도, 냉각속도 등에 의한 변형 및 불량현상을 분석하였고 이들을 극소화시킬 수 있는 냉각구조와 사이클 시간을 단축시킬 수 있는 사출성형조건을 제시하였다.

• 한국전기전자재료학회논문지
• /
• 제35권4호
• /
• pp.386-391
• /
• 2022

The gas insulation switchgear, which is a device for protecting a power system, cannot be supported by the insulation gas itself in a charge unit stored in a metal container. Therefore, molding technology is required to manufacture a gas insulation switch spacer. The APG method injection molding simulation was performed by applying the variables obtained through the physical properties of an epoxy composite used for manufacturing an insulating spacer to a moldflow software. After varying the temperature conditions of heater in the simulation, the thermal characteristics and the degree of hardening of the spacer were analyzed, based on which the optimum process conditions are presented.

• 한국전기전자재료학회논문지
• /
• 제37권1호
• /
• pp.56-62
• /
• 2024

By introducing curing kinetics and chemo-rheology for the epoxy resin formulation for ultra-high voltage gas insulated switchgear (GIS) Insulating Spacers, a study was conducted to simulate the curing behavior, flow and warpage analysis for optimization of the molding process in automatic pressure gelation. The curing rate equation and chemo-rheology equation were set as fixed values for various factors and other physical property values, and the APG molding process conditions were entered into the Moldflow software to perform optimization numerical simulations of the three-phase insulating spacer. Changes in curing shrinkage according to pack pressure were observed under the optimized process conditions. As a result, it was confirmed that the residence time in the solid state was shortened due to the lowest curing reaction when the curing holding pressure was 3 bar, and the occurrence of deformation due to internal residual stress was minimized.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 추계학술대회 논문집
• /
• pp.857-858
• /
• 2010

• 한국산학기술학회논문지
• /
• 제15권1호
• /
• pp.21-26
• /
• 2014

치과에서 사용되는 구강 치료용 요오드 용기는 개폐 시 용기의 캡에 부착되어 있는 칼날에 의해 치료용 실은 절단이 된다. 금속의 칼날은 요오드 용액과 반응하여 단기간에 부식이 되는 문제로 인해 환자의 위생에도 영향을 준다. 이러한 문제를 해결하기 위해 최근 세라믹 칼날로 대체되어진 제품들도 개발되어 생산되는데, 이때 세라믹 칼날은 수작업과 기계가공을 통해 만들어 진다. 본 연구에서는 세라믹 칼날을 분말사출성형공정으로 대량 생산할 수 있도록 20Cavity의 균일 충전을 위한 유동 시스템을 제안하였다. Moldflow를 이용하여 20cavity 유동성에 대한 시뮬레이션을 진행하였고, 금형제작과 수정을 통해 금형을 완성하였다. 사출성형 후 탈지와 소결공정을 통해 완성하고, 금형에 세라믹 칼날을 인서트 사출하여 캡 제품을 완성하였다. 본 연구를 통해 유효한 절단 성능을 갖는 세라믹칼날 대량생산 가능성을 검증하였다.

• 한국산학기술학회논문지
• /
• 제7권3호
• /
• pp.271-277
• /
• 2006

사출 성형 공정은 저비용으로 고품질의 제품을 대량으로 얻을 수 있는 제조 공정이지만. 성형품의 품질에 영향을 주는 인자의 수가 너무 많아 모든 경우에 대하여 실험을 수행하는 것은 시간적, 경제적으로 불가능하다. 따라서 최근에 시뮬레이션 도구를 활용하여 이러한 실험을 보조하고 있고, 실험계획법 및 여러 가지 최적화 기법들이 다루어지고 있다. 인자수가 많은 경우 각 입력인자 간의 교호작용 등도 고려하면서도 실험 횟수를 줄이는 기법으로 정립된 실험계획법을 적용하여 시뮬레이션 소프트웨어를 이용한 모의 실험 데이터를 도출하였으며, 이를 바탕으로 주변의 잡음에서도 강건한 설계를 할 수 있는 다구찌 기법을 사출 성형 공정에 적용하여 최적의 사출 성형 공정 조건을 나타내었다.