Mold-cavity melt-flow analysis

See injection molding melt flow melt flow mold-cavity melt-flow analysis residence time rheometer screw design viscosity. 

The polymer melt injected from the nozzle of the injection molding machine flows through the sprue, runner and gate, and finally enters the cavity. The, feed system is a generic term for the sprue, runner and gate. The feed system is usually included in the flow analysis as part of the flow channel upstream to the cavity (Fig. 1.2). 

In this study, a commercial mold-flow analysis program, Moldex3D copyrighted by CoreTech System at Hsinchu, Taiwan, has been chosen for toe analysis tool on simulating toe conditions of polymeric melt inside toe mold cavity throughout the process. The main features of toe program are simulation of thermo-mechanical history of molded lenses during toe process, typically... 

To examine the development of the solidified layer and the effect of passive heating on the development of the solidified layer, tiie flow of the polymer melt with passive heating was analyzed [11]. The mold cavity for simulation had a thickness of 1.2 mm and diameter of 86 mm, the same as those of our patterned magnetic media substrates. The initial melt temperature and mold temperature were 300°C and 100°C, respectively. Polycarbonate was used as the polymer material, and nickel was used as the stamper material. For the mold material and insulation layer, tool steel and polyimide were chosen, respectively. The flow rate and packing pressure are 14.15 cmVs and 3920 N/cm, respectively. For flow analysis of injection molding with passive heating, a mathematical model was constructed in the cavity and in the passively heated mold, consisting of the stamper the insulation layer and the... 

Similarly, increasing the mold temperature from 20°C to 60°C should result in a higher flow front temperature since the polymers heat loss dming filling will be reduced. The analyses that used the initial mold temperature predicted the melt temperature would rise by 11.1°C in the tensile bar cavity and 6.2°C in the flex bar cavity. However, the conduction analysis using the water temperature boimdaiy condition predicted lower melt temperatures at higher mold temperatures when in actuality the reverse is true. The difference between the initial mold surface temperature and the water temperature decreased as the mold temperature was increased. This corresponded to lower heat fluxes and lower predictions at higher mold temperatures. 

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