Design of an induction heating coil coupled with magnetic flux concentrators for barrel heating of an injection molding machine

2014 ◽  
Vol 229 (3) ◽  
pp. 518-527 ◽  
Author(s):  
Huy-Tien Bui ◽  
Sheng-Jye Hwang
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Magnetic Flux ◽  
Heating Rate ◽  
Induction Heating ◽  
Heating Time ◽  
Resistance Heating ◽  
Molding Machine ◽  
Heating Method ◽  
Heating Coil

In an injection molding machine, the conventional barrel heating system which uses resistance heating method (RH) has some drawbacks such as low heating rate, long heating time, and energy loss. With induction heating (IH) technique, the barrel can better handle almost all of these disadvantages. However, non-uniform temperature distribution on inside surface of a barrel is the main drawback of induction heaters. A working coil coupled with magnetic flux concentrators via adjustment of magnetic flux concentrator spacing to achieve uniformity of magnetic flux and temperature distribution on the inside surface of a barrel was proposed and experimented. Results showed that, when barrel was heated by induction heating method with the proposed induction heating coil, heating time to reach a specific temperature could be reduced, and heating rate increased compared to resistance heating method. With 8 mm pitch of magnetic flux concentrators on a coil, the temperature distribution was the most uniform.

Development of Barrel Heating via Induction in Injection Molding Machine

2015 ◽  
Vol 764-765 ◽  
pp. 249-253
Author(s):  
Huy Tien Bui ◽  
Sheng Jye Hwang
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Induction Heating ◽  
Heating System ◽  
Resistance Heating ◽  
Molding Machine ◽  
Injection Molding Machine ◽  
Heating Systems ◽  
Induction Heating System ◽  
Current Resistance

A barrel heating system will be developed by using induction heating instead of current resistance heating. The experiment results showed the induction heating system can change successfully the current resistance heating system in heated the barrel of injection molding machine. A working coil coupled with magnetic concentrator bars was also considered. Finally, the uniformity of temperature distribution is compared between two barrel heating systems.

Development of barrel heating system in injection molding machine via induction heating

2015 ◽  
Vol 21 (3) ◽  
pp. 244-249 ◽  
Author(s):  
Huy-Tien Bui ◽  
Sheng-Jye Hwang
Keyword(s):  
Temperature Distribution ◽  
Magnetic Flux ◽  
Induction Heating ◽  
Heating System ◽  
Resistance Heating ◽  
Uniform Temperature ◽  
Content Type ◽  
Uniform Temperature Distribution ◽  
Proper Design ◽  
Induction Heating System

Purpose – The purpose of this paper is to develop a barrel heating system using induction heating instead of resistance heating. And, a working coil for the induction heating system was designed so that the barrel has uniform temperature distribution. Design/methodology/approach – A coupling design combining the pitch of turns of working coil with the magnetic flux concentrators in the barrel induction heating system was developed to achieve uniform temperature distribution which was approximately the same as temperature uniformity obtained from that of resistance heating system. Findings – In contrast to resistance heating method, induction heating is more efficient because the heating is directly applied on the work-piece. Its heating rate is higher than that of resistance heating method. However, the uneven temperature distribution in the barrel is the main disadvantage of the induction heating system. But, with proper design of adjusting the pitch of turns at the center of working coil and adding magnetic flux concentrators at areas with lower magnetic flux, the barrel heating system via induction can achieve temperature distribution uniformity. Originality/value – Under proper design of working coil, the barrel heating system by induction method can achieve the same uniform temperature distribution as the barrel heated by resistance method, and could be practically used in an injection molding machine.

Coupled Effects of Heating Method and Rate on the Measured Nonisothermal Austenization Temperature of Steel SUS420J1 in Heat Treatment

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Hongze Wang ◽  
Yosuke Kawahito ◽  
Yuya Nakashima ◽  
Kunio Shiokawa
Keyword(s):  
Heat Treatment ◽  
Temperature Distribution ◽  
Heating Rate ◽  
Induction Heating ◽  
Laser Heating ◽  
Treatment Method ◽  
Infrared Heating ◽  
Heating Rates ◽  
Element Analysis ◽  
Heating Method

Steel SUS420J1, which is the key material of turbine blade, is generally treated by heat to improve the strength prior to use. And the austenization process at different heating rates would determine the depth and width of heat treatment. In this paper, the austenization temperatures in heat treatment with the heat from induction wire, infrared lamp, and laser are measured, respectively. The effect of heating rate on the austenization temperature has been investigated. The research results show that the measured austenization temperature increases with the heating rate. And this trend is specially enlarged in the heat treatment method with larger gradient of temperature distribution, e.g., laser. The calculated phase transformation threshold shows that negative linear relationship exists between the logarithmic heating rate and the logarithmic austenization threshold for both induction heating and infrared heating, while abnormal relationship exists for laser heating. Thermal finite element analysis (FEA) models are then developed to calculate the temperature distributions in these three heating methods, and the calculated results show that the nonuniform temperature distribution leads to the gap between the measured austenization temperature and that of the material, which also leads to the abnormal variation law of austenization threshold in laser heating. The measured austenization temperature in induction heating method is thought to be the closest to the actual austenization temperature of the material among these three methods. This paper provides a guide for choosing the proper parameters to heat the steel SUS420J1 in hardening.

Estimate the Melt Flow Length with Internal Induction Heating for the Injection Molding Process

2020 ◽  
Vol 863 ◽  
pp. 97-102
Author(s):  
Huynh Duc Thuan ◽  
Tran Anh Son ◽  
Pham Son Minh
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Heating Rate ◽  
Induction Heating ◽  
Heating System ◽  
Mold Temperature ◽  
Heating Process ◽  
Injection Molding Process ◽  
Molding Process ◽  
Internal Induction

In this paper, an induction heating system was applied to the heating stage in the injection molding process. Through simulation and experiment, the heating process was estimated by the temperature distribution and the heating rate. In the simulation, the mold temperature was increased from 30°C to 180°C in 9 s. Therefore, the heating rate was higher than 16°C/s, which represents a positive result in the field of mold heating. Additionally, the temperature distribution revealed that the higher temperature is concentrated on the gate area, while the outside of the mold cavity is at a lower temperature. The same parameters were applied to both the experiment and the simulation, and the results were in good agreement.

Numerical Simulation of Temperature Field in Barrel of Injection Molding Machine during Induction Heating Process Based on ANSYS Software

2009 ◽  
Vol 87-88 ◽  
pp. 16-21 ◽  
Author(s):  
Shi Jia Chang ◽  
Peng Cheng Xie ◽  
Xue Tao He ◽  
Wei Min Yang
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Injection Molding ◽  
Induction Heating ◽  
Heating Process ◽  
Magnetic Vector Potential ◽  
Ansys Software ◽  
Molding Machine ◽  
Injection Molding Machine ◽  
Field Problem

A finite element model of temperature field coupled with electromagnetic field has been established based on induction heating theory including Maxwell’s equations, thermal conductivity differential equation and magnetic vector potential to simulate the induction heating process of barrel of injection molding machine by universal ANSYS software, and to obtain temperature field of the barrel related to time variation. The coupled thermal and electromagnetic field problem taking account of nonlinear materials characteristics related to temperature was discussed. The induction heating process of barrel was analyzed, and the temperature distribution and its variation with time were obtained.

Uniformity Analysis of Temperature Distribution in the Grating Embossing Mold by Induction Heating

2013 ◽  
Vol 562-565 ◽  
pp. 1267-1272
Author(s):  
Jian Jun Zhi ◽  
E Zhen Chen ◽  
Yu Cai Che ◽  
Qi Ren Zhuang
Keyword(s):  
Temperature Distribution ◽  
Induction Heating ◽  
Great Influence ◽  
Heating Time ◽  
Air Gap ◽  
Temperature Fields ◽  
Mold Surface ◽  
Exciting Current ◽  
Exciting Frequency ◽  
Current Densities

In order to obtain uniform temperature distribution in an embossing mold heated by induction used for replica of plastic gratings, temperature fields in the mold are analyzed by using electromagnetic-thermal coupling field of ANSYS software. The results indicate that the air gap between the induction heating coils and heating element, and the coils current density, have a great influence on the temperature distribution, while the exciting frequency has little. When an exciting current of 1636 A*N, frequency 25 kHz and heating time as 70 seconds, the optimal air gap width is of 4 to 5 mm. At the same time, reduce the exciting current densities can improve temperature uniformity on mold surface.

Experimental rapid surface heating by induction for injection molding of large LCD TV frames

2014 ◽  
Vol 34 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Shih-Chih Nian ◽  
Che-Wei Lien ◽  
Ming-Shyan Huang
Keyword(s):  
Standard Deviation ◽  
Injection Molding ◽  
Heating Rate ◽  
Induction Heating ◽  
Simulation Software ◽  
High Heating Rate ◽  
Mold Surface ◽  
Temperature Uniformity ◽  
Heating Efficiency ◽  
High Heating

Abstract The use of electromagnetic induction heating on achieving high mold temperature has been proven to effectively improve the appearance quality of injection molded parts. However, until now, the method has only successfully been used on heating small mold surfaces. This study aims to apply the method on a large injection mold that is used for producing 42-inch LCD TV frames. With the goals of achieving heating efficiency and uniformity, the main focus in this research is designing the induction coil. Initially, three types of induction coils – a single-layered coil with currents that flow in one direction, a single-layered coil with currents that flow in opposite directions, and a two-layered coil – were compared to confirm their heating rates; the best one was then chosen. Additionally, evaluation of various induction coils was preceded with commercial simulation software that supports electromagnetic and thermal analyses. An experiment involving heating a simple workpiece with a heated area similar to that of the male mold plate of the LCD TV frames was conducted to confirm its heating rate and uniformity. Real injection molding LCD TV frames assisted with induction heating was then carried out. Experimental results depicted that: (1) a single-layered coil with currents that flow in one direction performed best; (2) that it heated the simple workpiece at a high heating rate of 5.5°C/s with reasonable temperature uniformity (standard deviation: 5.1°C); and (3) induction heating of a 42-inch LCD TV frame mold surface in practical injection molding provided a high heating rate of 4.5°C/s with favorable temperature uniformity (standard deviation: 4.0°C).

scholarly journals The feasibility of external gas-assisted mold-temperature control for thin-wall injection molding

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880610 ◽  
Author(s):  
Pham Son Minh ◽  
Thanh Trung Do ◽  
Tran Minh The Uyen
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Heating Rate ◽  
Temperature Control ◽  
Mold Temperature ◽  
Cavity Surface ◽  
Thin Wall ◽  
Mold Surface ◽  
Hot Gas ◽  
Wall Injection

Simulation and experimental testing were conducted on an external gas-assisted mold-temperature control combined with a pulsed cooling system used for thin-wall injection molding to determine its effect on the heating rate and temperature distribution of a mold surface. For mold heating via external gas-assisted mold-temperature control, a hot gas was directly discharged on the cavity surface. Based on the heat convection between the hot gas and the cavity surface, the cavity temperature rose to the target value. Practically, the gap between the heating surface and the gas gate is an important parameter as it strongly influences the heating process. Therefore, this parameter was analyzed under different values of plate-insert thickness herein. Heating was elucidated by the temperature distribution and heating-rate data detected by the infrared camera and sensors. Then, external gas-assisted mold-temperature control was applied for the thin-wall injection-molding part of 0.5 mm thickness with the local-gate-temperature control. The results show that with 300°C gas temperature, the heating rate could reach 9°C/s with a 0.5-mm stamp thickness and a 4-mm gas gap. The results show that with local heating at the melt-entrance area of the mold plate, the cavity was filled with a 20-s heating cycle.

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