• 제목/요약/키워드: Mold Filling Process

검색결과 212건 처리시간 0.02초

용탕유동과 응고를 고려한 주조공정의 유한요소해석 (Finite element analysis of casting processes considering molten-metal flow and solidification)

  • 윤석일;김용환
    • 한국정밀공학회지
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    • 제13권3호
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    • pp.110-122
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    • 1996
  • Finite element analysis tool was developed to analyze the casting process. Generally, casting process consists of mold filling and solidification. Both filling and solidication process were simulated simultaneously to investigate the effects of process variables and to predict the defect. At filling process, thermal coupling was especially considered to investigate thermal history of material during the filling stage. And thermal condition at the final stage of filling is used as the initial conditions in a solidification process for the exact simullation of the actual casting processes. At mold filling process, Lagragian-type finite element method with automatic remeshing scheme was used to find the material flow. A perturbation method with artificial viscosity is adopted to avoid numerical instability in low viscous fluid. At solidification process, enthalpy-based finite element method was used to solove the heat transfer problem with phase change. And elastic stress analysis has been performed to predict the thermal residual stress. Through the FE analysis, solidification time, position of solidus line, liquidus line and thermal residual stress are found. Through the study, the importance of combined analysis has been emphasized. Finite element tools developed in this study will be used process design of casting process and may be basic structure for total CAE system of castings which will be constructed afterward.

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MoldFlow를 이용한 신발 사출금형 러너부 형상 최적화 (Shoemoulds Runner Shape Optimization using MoldFlow)

  • 류미라;서영백;문병주;박흥식
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1483-1486
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    • 2003
  • Injection mold is a manufacturing process used to produce the various parts of complicated shape at a low cost. Many factors such as, section shape, resin and mold temperature, filling time, etc, affect on the quality of injection part during injection molding process. The precent study, was carried out the shrinkage analysis of shoes injection mold to optimize runner shape based on filling and packing pressure with MoldFlow. Taguchi design and analysis of variance are used to optimize injection mold design.

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저압주조에 의한 자동차 Al Wheel의 제조(I) : 유동 및 응고해석 (Production of Automobile Al Wheel by Low-Pressure Die Casting (I) : Flow and Solidification Simulation)

  • 추인호;류성곤;최정길
    • 한국주조공학회지
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    • 제18권6호
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    • pp.578-585
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    • 1998
  • A multi-purpose code MAGMA was employed for mold design and process control in producing Al wheel by lowpressure die casting. Three-dimensional solid modeling was followed by mesh generation of casting and molds(top, bottom and side). The simulation of stability of casting cycle time, mold filling simulation with pressure variation from P1 to P2, solidification simulation by solidification time and feeding criteria, and temperature distribution of molds during processes were studied in this research. The thermal stability of molds was attained after 5 cycles when molds were preheated at $400^{\circ}C$. The pressure increase from P1 to P2 for mold filling was evaluated as slightly higher, and 6 seconds were taken for the mold filling. The cycle time was believed to be designed properly judged from the solidification time of casting and open/close time of molds.

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저온 주조법을 응용한 Al-Zn-Mg-Cu 합금의 반응고 성형 (Semi-Solid Forming of Al-Zn-Mg-Cu Alloy Applying Low-Temperature Casting Process)

  • 김정민;김기태;정운재
    • 한국주조공학회지
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    • 제22권2호
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    • pp.82-88
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    • 2002
  • Al-5.5Zn-2.5Mg-l.5Cu semi-solid slurry was prepared by cooling the liquid metal with a low superheat to a solid and liquid co-existing temperature. Relatively round solid particles could be obtained in the slurry through the simple process. The prepared slurry was deformed into the metallic mold by a press and the mechanical properties of obtained specimens were investigated. Mold filling ability of the alloy slurry was also investigated and compared with that of A356 alloy. Al-Zn-Mg-Cu alloy showed lower mold filling ability than A356 alloy probably because small amount of eutectic phase is present and the heat of fusion generated during solidification is smaller than that of A356 alloy.

급속 금형가열에 의한 박육 사출성형의 유동특성 개선에 관한 연구 (A Study on Improvement of Flow Characteristics for Thin-Wall Injection Molding by Rapid Mold Heating)

  • 박근;김병훈
    • 소성∙가공
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    • 제15권1호
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    • pp.15-20
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    • 2006
  • The rapid thermal response (RTR) molding is a novel process developed to raise the temperature of mold surface rapidly to the polymer melt temperature prior to the injection stage and then cool rapidly to the ejection temperature. The resulting filling process is achieved inside a hot mold cavity by prohibiting formation of frozen layer so as to enable thin wall injection molding without filling difficulty. The present work covers flow simulation of thin wall injection molding using the RTR molding process. In order to take into account the effects of thermal boundary conditions of the RTR mold, coupled analysis with transient heat transfer simulation is suggested and compared with conventional isothermal analysis. The proposed coupled simulation approach based on solid elements provides reliable thin wall flow estimation for both the conventional molding and the RTR molding processes.

다구찌 방법을 이용한 폴리아미드 성형품의 충전 불균형에 관한 연구 (A Study on the Filling Imbalance of Polyamide Molding by Taguchi Method)

  • 한규택;정영득;구양;김병탁;김형제;한성렬
    • 한국기계가공학회지
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    • 제3권4호
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    • pp.95-100
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    • 2004
  • Plastics is used to produce precise parts with an inclusion of a reinforcement material such as glass fiber or carbon fiber to improve the dimension accuracy. The plastic goods can be produced with inaccurate dimensions, low mechanical strength, or residual stress due to the over packing of cavity inside, if the filling balance of melt resin is not accomplished. To overcome this problem, it is necessary to design the runner system with the geometrical balance at the mold design stage. However, even if the balanced runner system is achieved, a severe filling imbalance is observed practically in a multi-cavity mold. In this study, experiments were performed with Taguchi method to achieve the filling balance in multi-cavity mold with a symmetric runner system, by the use of pure PA and PA with glass fiber 33%. The experimental results were investigated to understand the effect of related molding factors on the filling imbalance for two resins.

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사출성형의 충전조건 선정에 관한 연구 (A study of estimation of filling phase condition in injection molding process)

  • Jo, Y.M.;Kwon, O.J.;Kim, J.D.
    • 한국정밀공학회지
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    • 제12권3호
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    • pp.110-118
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    • 1995
  • The filling phase analysis of the injection molding process for thermoplastics was applied to predict pressure, themperature and shear stress in the test mold, and the results were compared with the experiment using 30% glass fiber added ABS resin. The finite difference method was used in the analysis considering the effects of heat transfer between molten polymer and mold wall, and also frictional heating by shear flow. The analysis results were considered as a method to improve the quality and the productivity of injection molding process. Using the analysis results, the molding factors such as mold-ability of polymers, performance of injection molding machine, positioning of gate and dimendsioning of runner in the injection molding process can be estimated at the design stage of mold for good quality and productivity.

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500um급 8캐비티 사출금형설계 제작 및 성형기술 (Manufacturing and Molding Technology of $500{\mu}m$ 8Cavity Injection Molding System)

  • 이성희;조광환;이종원;고영배
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2008년도 추계학술대회 논문집
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    • pp.444-447
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    • 2008
  • Recently, the need of thin-walled injection molding and enhancement of its productivity is greatly increased. In this study, we designed and manufactured a injection molding system, which can mold a part with the thickness of $500{\mu}m$ and 8 cavity. And processing technique for the multi-cavity injection molding system, which is capable of mass productivity on the plastic parts, was considered. The problems of unbalance/imbalance on the molding process for the multi-cavity mold were predicted by numerical analysis using plastic injection molding commercial code. In addition, controllable system of melt front filling was introduced for a balanced filling using the mold temperature sensor on injection mold. It was shown that balanced filling with the suggested injection molding system was possible for $500{\mu}m$ plastic parts with 8 cavity layout.

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Mg합금의 반용융가압주조시 주조조건에 의한 금형충전성 및 유동성 변화 (A Study on Mold Filling and Fluidity of Mg Alloy in Thixocasting)

  • 정운재;김기태;홍준표
    • 한국주조공학회지
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    • 제15권2호
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    • pp.184-193
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    • 1995
  • Effects of process parameters during thixocasting, such as solid volume fraction, mold temperature and extrusion ratio, on the mold filling behaviour and fluidity of Mg alloy(AZ91D) have been investigated. The semi-solid ingot held for 60 minutes at the semi-solid temperature range did not contain the equilibrium volume fraction of solid as expected from the phase diagram. Therefore, in order to obtain the desired solid fractions, and to suppress the exaggerated grain growth during heating, it was required to heat the ingot rapidly up to the temperature $10^{\circ}C$ higher than the semi-solid temperature suggested from the phase diagram for a specific volume fraction of solid. The experimental results show that mold filling behaviour and fluidity can be improved with the use of the higher mold temperature and the lower volume fraction of solid, but remain nearly unaffected by the change of extrusion ratio.

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충전과 상변화 현상을 포함한 주조과정에 대한 연구 (A Study of a Simultaneous Filling and Solidification During Casting Process)

  • 임익태;김우승
    • 대한기계학회논문집B
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    • 제23권8호
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    • pp.987-996
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    • 1999
  • An algorithm for modeling the filling of metal into a mold and solidification has been developed. This algorithm uses the implicit VOF method for a filling and a general implicit source-based method for solidification. The model for simultaneous filling and solidification is applied to the two-dimensional filling and solidification of a square cavity. The effects of the wall temperature and gate position on the solidification are examined. The mixed natural convection flow and residual flow resulting from the completion of a filling are included in this study to investigate the coupled effects of the filling and natural convection on solidification. Two different filling configurations (assisting flow and opposite flow due to the gate position) are analysed to study the effects of residual flow on solidification. The results clearly show the necessity to carry out a coupled filling and solidification analysis including the effect of natural convection.