Microcellular Injection Gas Injection System Optimization And Process Research

Microcellular injection molding can reduce the quality of the product while ensuring the mechanical properties of the product,and greatly improve the processing technology and other properties of the product.Therefore,the microcellular injection molding technology has been widely used.The gas injection system is a very important part of microcellular injection molding.The existing microcellular injection gas injection system can easily generate a gas surge at the instant of gas injection,which will cause the single-phase melt prepared to be insufficient,eventually the product has quality problems.This subject first builds a visual experiment platform to visually study the gas injection process of the existing gas injection system,and conducts a visual gas injection experiment under different pressure conditions.Analyze the changes of the bubble state during the gas injection process of high-speed video recording,and collect the pressure changes in the visualization device and perform data processing and analysis,prove that there is a real phenomenon of gas surge,and find the mathematical relationship between gas surge and pressure.Afterwards,according to the formation mechanism of the gas surge phenomenon,a gas injection system optimization scheme with a low-pressure branch was proposed and visually verified.The experimental data was processed and analyzed and compared with the visual experiment results of the gas injection system before improvement.Judge the effectiveness of the improved gas injection system to suppress the gas surge phenomenon,and obtain the relationship between the gas injection process and the aperture and pressure of the restrictor.On the basis of the visualization experiments that proved that the gas injection system was improved effectively,the improved gas injection system was used to perform microcellular injection molding experiments,with the factors of restricting pore size,melt back pressure,gas injection pressure difference and gas injection time,design a four-factor three-level DOE experiment.Measure the performance of microcellular injection molded products,analyze the stability of product performance,study the effects of experimental factors on microcellular products' gas injection volume,weight loss ratio and impact strength and optimize the design.Aiming at the shortcomings of the existing microcellular injection gas injection control system and data acquisition system which are independent of each other,the synchronization is poor,and the experimental operation is complicated,redesigning the microcellular injection gas injection measurement and control system based on Lab VIEW,which integrates gas injection control and data acquisition,greatly improved the experimental efficiency and measurement and control accuracy.