• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.2
• /
• pp.60-65
• /
• 2012

This paper deals with an CAE analysis and optimization of injection molding for a mobile phone cover. Two design goals are established in the optimization; one is to switch over the feed system from cold runner to hot runner for the purpose of reducing material costs, and the other is to minimize the warpage in order to improve product quality. By the full-factorial experiments for design parameters, we showed that the cold runner design could be changed to the hot runner design by replacing the current resin with a new resin of higher fluidity. In addition, we could significantly reduce the warpage of the cover product under the hot runner system by optimizing packing pressure and packing time.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.05a
• /
• pp.329-332
• /
• 2008

Flow imbalance among the cavities was often observed in multi-cavity mold. The flow imbalance affects on the dimensions and physical properties of melded articles. First of all, the origin of flow imbalance is geometrical imbalance of delivery system. However, even the geometry of delivery system is balanced the cavity imbalance is being developed. This comes from the temperature distribution in the cross-section of runner, which is affected by the operational conditions. In this study, experimental study of flow imbalance has been conducted for various injection speeds. This study also suggests new runner design to eliminate flow imbalance in multi-cavity injection mold. Simulation and experimental results showed suggested new designed runner could eliminate or reduce flow imbalance in multi-cavity injection mold.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.716-719
• /
• 1997

This paper describes the runner and gate design capabilities of the RAMEDS system, which is a specialized CAD system for injection mold design, dcvcloped using the application procedure interface of the Unigraphics system. In this system, runners lying on sculptuted partlng surface can be modeled by projecting the runner trajectory on the surface and sweeping a selected cross section along the projcctcd trajectory. In addtion, the system provides solid modeling capabilities for three types of gates currently.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.12
• /
• pp.1021-1030
• /
• 2016

The runner system of the injection mould and the injection volume of the injection molding process greatly affect the quality of the produced part. The goal of this paper is the design of the runner system and the prediction of the injection volume for the injection moulding of a housing part of small-size air cleaner to improve the formability through the three-dimensional injection moulding analysis. The effects of the runner system of the mould on the injection moulding characteristics are investigated. From the results of the investigation, a proper design of the runner system with uniform filling characteristics and the minimized defect formation is obtained. In addition, the influence of the moving distance of the screw on filling characteristics, weldline formation and deformation characteristics is examined. From the results of the examination, an appropriate moving distance of the screw for the housing part of small-size air cleaner is estimated.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.11a
• /
• pp.316-321
• /
• 2000

Die Casting is one of the forming methods to manufacture large number of products with short period time and clean surface by high forming pressure and temperature of cast alloy. Die design is composed of selection of cast alloy, design of die casting product, runner and gate design etc. In reality, however, die design of die casting has been performed by trial and error method, which cause economic and time loss. This paper describes a research work of developing computer-aided design of die casting product and die design. Approach to the CAD system has been written in AutoLISP on the AutoCAD with personal computer. In this study, die design system for gate of die casting process has been developed to present algorithm for automation of die design, especially runner-gate system. As forming process and die design system using 3-D geometry handling are integrated with technology of process planning, die design is possible to set. In addition, specific rules and equations for the runner-gate system have been presented to avoid too many trails and errors with expensive equipment. It is possible for engineers to make automatic and efficient die design of die casting and it will result in reduction of expense and time to be required. An example is applied to cap-shaped casting using proposed algorithm.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.9
• /
• pp.192-203
• /
• 2001

The design of gate and runner(delivery system) is one of the most important subject in injection molding. Delivery system is a channel to flow the polymer melt from the injection molding machine to the mold cavities. Also, delivery system affect quality and productivity of the part. The synthesis of delivery system of injection molding has been done empirically, since it requires profound knowledge about the moldability and causal effects on the properties of the part, which are not available to designers through the current CAD systems. GATEWAY is a knowledge module which contains knowledge to permit non-experts as well as mold design experts to generate the acceptable geometries of gate and runner far injection molded parts. A knowledge-based CAD system is constructed by adding the knowledge module, GATEWAY, to an existing geometric modeler. A knowledge-based CAD system is a new tool which enables the concurrent design and CIM with integrated and balanced design decisions at the initial design of injection molding.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.3
• /
• pp.158-168
• /
• 2001

Die design of die casting is composed of selection of cast alloy, design of die casting product, runner design and gate design, etc. In reality, however, die design of die casting has been performed by trial and error method, which cause economic and financial loss. Nowadays, several FEM(finite element method) and FDM(finite difference method) codes have been developed to analyze process of die casting, but this is just confined to an offer of limited information for die design of die casting. In this study, die design system for gate of die casting process has been developed to present algorithm for automation of die design, especially runner-gate system. In addition, specific rules for runner-gate system have been presented to avoid too many trials and errors with expensive equipment. It is possible for engineers to make automatic and efficient die design of die casting and it will result in reduction of expense and time to be required.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.1028-1031
• /
• 1997

The SS (Semi-solid) diecasters usually cany out the SS d~ecastmg experiments before producing new products. At the SS diecasting stages, the runner-gate part is always repeatedly corrected, which leads to a lengthened processing time and increased processing cost. The SS diecasting die design should consider component system factors. such as runner, gate, biscuit, overflow and airvent. A large amount of experience is essential in manual assessment and if the design is defective, much time and a great deal of efforts will be wasted in the modification of the d~e. Thus human negligence should be minimized. In this study, die design system for SS diecasting process has been developed to present algonthm of die design, especially runner-gate system. In addition, specific rules and equations for runner-gate system have been presented to avoid too many trials and errors with expensive equipment. It is possible for engineers to be efficient die design of SS diecasting and it will result in reduction of expense and time to be required. And we developed CAD system for SS diecasting die design by AutoLISP language under AutoCAD using proposed algorithm and the database. In addition, we developed the vector analysis program for filling pattern of SS metals.

• Design & Manufacturing
• /
• v.2 no.5
• /
• pp.25-29
• /
• 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 imbalance have been observed. Filling imbalance could be decreased by modifying processing conditions such as injections rate, mold temperature, injection pressure, melt temperature that are related to shear, viscosity. In this study, a series of experiment was conducted to investigate filling imbalance variation when modifying runner layout and ploymer and to determine which processing condition influences as the primary cause of filling imbalance in geometrically balanced runner system. The filling imbalance was desreased up to result range of $3{\leq}DFI{\leq}8(%)$ by using a new runner system for balanced filling.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.10
• /
• pp.1021-1028
• /
• 2015

Subminiature lenses are currently widely used in mobile phone cameras and are usually produced by injection molding. The lens molding process has the unique feature of a runner volume that is much larger than the part volume, and this feature should be considered when determining the mold design and molding conditions. In this study, a shell-type runner was proposed as an alternative to the conventional cylindrical runner used for lens molding. An injection molding simulation was performed by applying the proposed shell runner, and the simulation results were compared with those from the cylindrical runner case. It was found that the shell runner could considerably reduce the runner cooling time with only a slight increase in the injection pressure. The effect of the runner thickness was then investigated numerically in terms of the mold filling and cooling characteristics, from which an optimal runner thickness could be determined.