• Title, Summary, Keyword: Injection molding gate

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A Study on the Formation of Gate Mark in Injection Molding (사출성형에서 Gate Mark의 형성에 관한 연구)

  • Kim, J.M.;Kim, D.W.;Hwang, S.J.;Lyu, M.Y.
    • Transactions of Materials Processing
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    • v.15 no.8
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    • pp.628-632
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    • 2006
  • The gate mark in injection molded part is a kind of surface defects. The formation of gate mark has been investigated in this study. SEM photographs and surface roughness have been examined to study gate mark. The specimens were molded for various injection conditions, such as injection temperature, mold temperature, and injection speed. Gate diameter and mold surface condition were also molding variables. Gate marks were reduced as injection speed and mold temperature increased. Gate diameter and injection temperature did not affect the gate marks. No etching of mold surface showed no gate marks for any molding conditions.

A Study on Decision of gate location for Injection molding of Automobile air cleaner Upper cover (자동차용 에어클리너 상부커버 사출성형에서 게이트의 위치 결정)

  • Jang, Sung-Min;Kim, In-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4411-4417
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    • 2015
  • The proper design of the gate location for injection molding of plastic goods is obtained from three-dimensional injection molding analysis for various design alternatives. This paper is study on effect of gate location in injection molding. It have a decisive impact on productivity and quality of plastic goods. This objectives of this paper is to analysis effect of hot runner gate location for resin filling, weld line, injection pressure to manufacture of automobile air cleaner upper case with injection molding machine. Thus, to analysis these problems in this paper, location of gate are gave variety in 4 CASEs. In this paper, the CAE simulation considering each variations in location of gate is performed to predict the cause of faulty which appears in the injection molding process.

A Study on the Molding Technology for the Preform of Blow Molding Through Compression Molding (압축성형을 통한 블로우 성형품용 프리폼 성형기술 연구)

  • Choi, S.H.;Min, H.K.;Lyu, M.Y.
    • Transactions of Materials Processing
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    • v.16 no.1
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    • pp.3-8
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    • 2007
  • Novel compression molding system for preform has been developed in this study. The preforms for injection blow molding and injection stretch blow molding are being manufactured by injection molding. However it contains gate mark that affects the bottom crack in the PET bottle. The compression molded preform does not contain gate mark, thus the appearance quality of bottle has been increased and the residual stress near gate(bottom of the bottle) has been reduced. The thickness distributions, haze, and transmittance are well accepted for the preform. Also, flow characteristics of the resin between a core and cavity could be analyzed through computer simulation.

Improving the Whitening Phenomenon Technology for Preform PET Injection Molding by Using a Ceramic Insulation Gate (세라믹 단열 게이트를 이용한 블로우성형용 PET 프리폼의 백화현상 저감 기술)

  • Kwak, Tae-Soo;Hwang, Deok-Sang;Kang, Byung-Ook;Kim, Tae-Kyu
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.6
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    • pp.63-68
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    • 2017
  • The purpose of this study is to improve the whitening phenomenon around the PET preform gate for blow molding. CAE analysis of plastic injection molding has been applied to design of preform shape and select the injection molding conditions. A ceramic insulation gate with lower thermal conductivity than metal is applied to improve the whitening phenomenon created around the gate in the injection molding process. According to the results of CAE analysis, the warpage deformation at the square corner was estimated to be about 0.34 mm at the bottom. From the results of the temperature history analysis, it was confirmed that the resin near the gate cooled more rapidly than the cavity. Ceramic insulated gates were fabricated to reduce the cooling rate and experiments were conducted to confirm the effectiveness of the whitening phenomenon improvement. As a result of the ceramic insulation gate experiment, it was confirmed that the whitening phenomenon was significantly reduced around the gate.

A Study on the Fiber Orientation and Fiber Content Ratio Distribution during the Injection Molding for FRP (FRP의 사출성형에 있어서 섬유배향상태와 섬유함유율분포에 관한 연구)

  • Kim J. W.;Lee D. G.
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.252-257
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    • 2005
  • Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation' orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line in injection-molded products is assessed. And the effects of fiber content and injection mold-gate conditions on the fiber orientation are also discussed.

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Effects on the process factors of blow molding affects to the PET bottle (블로우 성형공정변수가 PET 용기에 미치는 영향에 관한 연구)

  • Kim, Jong-Dug;Go, Young-Bae;Kim, Ok-Rae;Park, Hyung-Pil;Kim, Hong-Ryul;Kwon, Chang-Oh
    • Journal of the Korea Society of Die & Mold Engineering
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    • v.2 no.6
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    • pp.7-10
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    • 2008
  • Injection-stretch blowing system for preform has been developed in this study. The preforms for injection blow molding and injection stretch blow molding are being manufactured by injection molding. However it contains gate mark that affects the bottom crack in the PET bottle. The compression molded preform does not contain gate mark, thus the appearance quality of bottle has been increased and the residual stress near gate(bottom of the bottle) has been reduced. The thickness distributions, haze, and transmittance are well accepted for the preform. Also, flow characteristics of the resin between a core and cavity could be analyzed through computer simulation.

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Verification of gate balancing equation using injection molding analysis (사출성형해석 연구를 이용한 게이트 밸런스 계산식의 검증)

  • Han, Seong-Ryeol
    • Journal of the Korea Society of Die & Mold Engineering
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    • v.12 no.3
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    • pp.55-59
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    • 2018
  • In a multi-cavity mold having a runner layout of a fish bone structure, problems of unbalanced filling between cavities occur constantly. Unbalanced charging lowers the dimensional accuracy of a molded article and causes deformation after molding. To solve this problem, the gate size connected to each cavity is adjusted using the BGV (Balanced Gate Value) equation. In this paper, in order to solve the filling imbalance problem of the runner layout mold of fish bone structure through injection molding analysis study, we compared the charging imbalance phenomenon before and after improvement after adjusting the gate size by applying BGV equation. From the results of the molding analysis, the shrinkage ratio before and after the improvement of the molded article was improved by only about 0.08%. Based on these results, it was confirmed that the charging imbalance problem was not significantly improved even when the BGV equation was applied.

Gate Location Design of an Automobile Junction Box with Integral Hinges (복합힌지를 갖는 차량용 정션박스의 게이트 위치설계)

  • 김홍석
    • Transactions of Materials Processing
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    • v.12 no.2
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    • pp.134-140
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    • 2003
  • Polymers such as polypropylene or polyethylene offer a unique feature of producing an integral hinge, which can flex over a million times without causing a failure. With such advantage manufacturing, time and cost required at the assembly stage can be eliminated by injecting the whole part as one piece. However, due to increased fluidity resistance at hinges during molding, several defects such as short shot or premature hinge failure can occur with the improper selection of gate locations. Therefore, it is necessary to optimize flow balancer in injection molding of part with hinges before actually producing molds. In this paper, resin flow patterns depending on several gate positions were investigated by numerical analyses of a simple strip part with a hinge. As a result, we found that the properly determined gate location leads to better resin flow and shorter hesitation time. Finally, injection molding tryouts using a mold that was designed one of the proposed gate systems were conducted using polypropylene that contained 20% talc. The experiment showed that hinges without defects could be produced by using the designed gate location.

Effects of Packing Parameter on Plastic Article Dimensions in the Plastic Injection Molding (사출성형 시 성형제품치수에 미치는 패킹변수의 영향)

  • Kim, Bum Joon;Shin, Ju Kyung;Lee, Jeong Goo;Sohn, Il Seon
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.1
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    • pp.9-13
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    • 2014
  • The molding process can be divided into five separate steps: plastification, injection, holding, cooling, and finally ejection. In the plastic injection molding, the effect factor such as mold temperature, injection speed, packing pressure and inhomogeneous cooling under packing process affects both the article dimension and physical characteristics. Especially, the packing pressure is the most critical factor to affect molded articles quality among the packing parameters. In this paper, the CAE simulation considering the molding condition is performed to predict the faulty cause which appears in the packing process between cavities of injection molding machine. From the results of CAE simulation, the packing phenomena according to the product form and the gate position was investigated to improve the article quality and minimize the various molding defects. The effect of packing pressure and gate number on the injection molding was discussed.