Research On Energy Consumption Analysis And Forcecast Method In Injection Molding Process

As one of the most commonly used method for polymer forming, injection forming has consumed more than 65 percent of the total energy of the plastic industry, which means that its energy consumption is rather huge. However, it is a very complicated process to evaluate the energy efficiency of injection molding. On the one hand it is because injection molding is a cycle process, and each stage all has its own character in energy consumption. On the other hand, lots of factors would affect the energy consumption of each stage, including the machines type, materials, process parameters and mold. The two complexities make it difficult to predict the energy consumption of injection molding. Nevertheless, it is of great meaningful to establish a prediction model of injection molding and to guide the manufacturer to produce product in a relatively low energy consumption condition. Thus, this thesis will focus on the research of setting up prediction models of cycle energy consumption and cycle time of the injection molding.This paper use both simulation and experiment methods respectively, to conduct orthogonal test for injection stage and plasticizing stage, determining the key factors and their ranking order that affect the stage energy consumption and stage time. Then, Single factor experiments are utilized to analyze the influence of speed on the stage energy consumption and stage time of the of mold close, mold open, thimble forward, thimble back stage, the influence of packing pressure on the packing energy consumption, the influences of injection speed, injection temperature and mold cavity size respectively on the injection energy consumption and injection time, the influences of rotating speed, plasticizing temperature and backpressure respectively on the plasticizing energy consumption and plasticizing time. Besides, the energy consumption percentage of each stage in the total cycle energy consumption is also been researched to study their percentage changing with the speed.According to the experimental data, curve fitting method is employed to build the energy consumption and time prediction models of the of mold close, mold open, packing, thimble forward, thimble back stage. Partial least squares regression analysis is used to set up the energy consumption and time prediction models of the injection stage and plasticizing stage.Fluctuation study and system error of the injection molding is studied through repeated experiment, which can be used to explain the prediction error of the cycle energy consumption model and cycle time model. Considering the energy consumption and efficiency, an evaluation method is put forward to help find a relatively better processing condition of different material. Evaluations of PS、ABS and PP are carried out to find their relatively better processing condition with speed.