Study on Induction Heating Coil for Uniform Mold Cavity Surface Heating

Abstract

Recently, energy saving is one of the important issues for polymer processing industry. Electromagnetic induction heating has many advantages such as fast heating and low energy consumption. Previous studies using electromagnetic induction heating for rapid tool heating have indicated that the temperature uniformity on a cavity surface is not easy to be achieved. In this paper, two different coils were used for heating uniform 7 mm thick hot work tool steel (JIS SKD61) surface. One is a four-row coil with opposite current directions and the other is a two-row coil with identical current directions. Magnetic flux concentrators were used to control magnetic field and heat the workpiece uniformly. The heating experiment results showed that coil with opposite adjacent current directions had more uniform temperature distribution on tool surface. The temperature uniformity was about 94%∼95%. The coil with identical adjacent current directions had higher average temperature and the temperature rose from 50 ∘ C to 150 ∘ C in 15 seconds.

Three-dimensional numerical modeling of an induction heated injection molding tool with flow visualization

“…S. Huang et al [17][18][19][20][21][22] have compared the performance of oil heating versus induction heating and found the latter to give best replication of micro structures. They also noticed that increasing the mold temperature above the phase transition temperature does not significantly improve the replication ability.…”

A novel method improving the temperature uniformity of hot-plate under induction heating

“…It implies that the more uniform temperature distribution can be achieved at higher target temperature of the hot-plate. 30 Following the same strategy of analysis, the temperature nonuniformity and difference at other target temperature of 140 ℃, 160 ℃, 200 ℃, and 240 ℃ under the same processing conditions at the target temperature of 180 ℃ can be simulated. Furthermore, the corresponding three-dimensional surface temperature color-map of the hot-plate under different target temperatures can found in the supplemental appendix C. These surface color maps may provide a guide to help determination of optimized processing conditions with uniform temperature distribution at the target surface of hot-plate.…”

Temperature Uniformity of Heated Mold Plate by Oscillating Heat Pipe

“…While Sung, Y. T. et al, [4] found that by using inductive heating, the standard deviation of temperature can be ranging from 1.44 o C to 25.82 o C. Standard procedure recommended that to get good parts, the mold surface temperature need to be in the range of ± 2.0 o C [2,5]. Uniformity of the temperature in the molding plate is of paramount important since it will affect the dimensional stability of the part produced.…”