Preplasticizing Theory And Energy Consumption Of Induction Heating Injection Machine

Polymer material in barrel of injection molding machine is usually transformed from unconsolidated powdery or granular solids into continual homogenized melt after being heated,compacted and mixed, which is called plasticization. The type of heating mode is the key part to the injection molding machine. Recently, most of injection heating systems are of resistance heating with shortcomings of low efficiency, high energy consumption. Comparatively, electromagnetic induction heating has advantages of fast temperature-rising, long service life and high thermal efficiency. However, sufficient theoretical guidance is not got such that electromagnetic induction heating has not been widely used in injection molding machine together with some technical problems in engineering application.Therefore, barrel heating and plastication process in the barrel were the research objects in the present thesis. Barrel temperature-rising process and characteristics of induction heating were analyzed through theoretical model and experiments. The work and conclusions are as follows:Based on electromagnetism and heat-transfer rules, the axial and radial temperature-rising of electromagnetic induction heating and resistance heating were modelled using magnetic-heat coupling ANSYS finite element method showing the advantages of low thermal inertia, the rapidity and uniformity of electromagnetic induction heating. This could be reflected by smaller difference between barrel internal temperature and external temperature for induction heating in contrast with great difference for resistance heating.The summerized injection-plastication models were used to analyze the heating way on output and energy consumption in solids transportation, melting and melt conveying considering the boundary temperature distribution in both heating ways.The plastication experiments were conducted using both heating ways. The effects of screw rotation and screw back pressure on output, sectional energy and overall energy consumption were provided proving the advantages of induction heating.In conclusion, here some elementary studies of the relationship between injection parameters and injection energy consumption of injection molding machine are proposed for exploring higher plastication efficiency. It is going to be a good basis for wide application of induction heating.