• Transactions of Materials Processing
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• v.13 no.7
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• pp.580-585
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• 2004

Almost all injection molds have multi-cavity runner system fur productivity and are designed with geometrically balanced runner system in order to minimize filling imbalance between cavity to cavity during processing. However, filling imbalances have been observed though geometrically balanced runner lay-out. Generally, these filling imbalances are due to thermal unbalance, viscosity, characteristic of polymers and so on. These kinds of filling imbalances have already been reported by Beaumont since 1997, but his research has mainly focused on filling imbalance at binary runner. In this study, we conducted an experimental study about the filling imbalances in unary branch runner as well as binary branch runner and inquired into the causes of filling imbalances. The results could be summarized as fellowing: Filling imbalances existed in multi-cavity mold with unary branch runner, it could be decreased by optimizing processing condition such as increasing injection rate, and it is almost proportion to each polymer's temperature sensibility.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.72-75
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• 2003

Almost all injection molds have multi-cavity runner system for productivity and are designed with geometrically balanced runner system in order to minimize filling imbalance between cavity to cavity during processing. However, filling imbalances have been observed though geometrically balanced runner lay-out are used. Generally, these filling imbalances are due to thermal unbalance, viscosity, characteristic of polymers and so on. These kinds of filling imbalances has already been reported by Beaumont[1] since 1997. In this study, we presented filling imbalaces in balanced runner that has unnary branch type lay-out through experimental tests. As a result of experiments, we could present the processing conditions for the balanced filling in geometrically balanced runner that has unnary branch type lay-out

• Journal of the Korean Society for Precision Engineering
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• v.25 no.10
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• pp.144-149
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• 2008

Configuration of filling imbalance which is originated from imbalanced share rate of melt on runner is changed by runner layout, runner shape, material property, injection pressure, injection speed, melt temperature and mold temperature. In this paper, we conducted a study of runner layout and shape that are main factors of filling imbalance. Other factors such as the sharp corner effect and the groove corner effect are recently released were also considered. The results of study are showed that filling rate of between inside and outside cavity was influenced on shape of runner. Especially, this study suggests a new runner system for filling balance by adapting the two effects of unary branch type runner at multi cavity mold and theoretical investigated flow in the sharp corner type runner.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.4
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• pp.47-52
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• 2008

Recently, the study for filling imbalance in thermoplastic polymer has gradually been increased. However, it is hard to find the researches for filling imbalance of thermoplastic elastomer(TPE). The experiment of filling imbalance was conducted for the three kinds of thermoplastic vulcanizes(TPVs) and PP polymer in the mold with geometrically balanced runner system(Unary Branch Type Runner System). In this experiment, the effects of the melt temperature, injection pressure and injection speed on the filling imbalance were investigated. There was also the imbalance in TPV injection molding process as well as in conventional injection molding with plastics. The tendency of filling imbalance in TPV injection molding specially decreased by taking place the hesitation of TPV melt.

• Design & Manufacturing
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• v.2 no.4
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• pp.5-10
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• 2008

Recently, the study for filling imbalance in thermoplastic polymer has gradually been increased. However, it is hard to find the researches for filling imbalance of thermoplastic elastomer(TPE). The experiment of filling imbalance was conducted for the three kinds of thermoplastic vulcanizes(TPVs) and PP polymer in the mold with geometrically balanced runner system(Unary Branch Type Runner System). In this experiment, the effects of the melt temperature, injection pressure and injection speed on the filling imbalance were investigated. There was also the imbalance in TPV injection molding process as well as in conventional injection molding with plastics. The tendency of filling imbalance in TPV injection molding specially decreased by taking place the hesitation of TPV melt.

• Design & Manufacturing
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• v.6 no.1
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• pp.52-57
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• 2012

Aspect of filling imbalance that is originated from imbalanced share rate in runner is changed by material property, runner layout that are factors of changing viscosity and by injection pressure, injection speed, melt temperature and mold temperature that are injection conditions. In this paper, we made a study of runner system that is one of factor of filling imbalance and Sharp Conner Effect and Groove Corner Effect that are recently released. The study are showed that filling rate of between inside and outside cavity was influenced on shape of runner. Also, we suggested runner system for filling imbalance by adapting the two effects at multi cavity of unary branch type and theoretical investigated flow in the Shrap Conner runner type.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.281-281
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• 2003

• Design & Manufacturing
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• v.2 no.5
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• pp.16-20
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• 2008

Almost all injection molds have multi-cavity runner system for mass production, which are designed with geometrically balanced runner system in order to accomplish filling balance between cavity to cavity during processing; However, even though geometrically balanced runner is used, filling imbalances have been observed. In these day, the CAE has been used widely in injection molding. However, CAE with fusion mesh can't indicate such as jetting, flow mark and filling imbalance in multi cavity mold. In this study, we investigated the filling imbalance according to runner shapes by CAE analysis. As a result in CAE, in case of binary branch runner system, filling imbalance was indicated between cavity to cavity, but the flow pattern of each cavity uniformed in unary branch runner system.