Process Simulation And Structure Optimization Of Injection Molding Parts With Short Glass Fiber Reinforced Thin Wall

In recent years,with the rapid development of science and technology,the basic industry represented by plastics industry has also developed rapidly.In order to meet the plastic parts strength and stiffness requirements,plastic parts toward the direction of thinning and lightweight.Composite materials of thin-walled pieces represented by glass fiber have coming into our daily life.Warpage is a major difficulty in the quality control of thin-walled parts.The main factors of warpage are material selection,plastic parts,mold structure,injection molding process and so on.The injection molding process and the structure of plastic parts have a great influence on the warping of thin-walled plastic parts.This paper mainly optimize the production process and the structure of plastic parts through the creation of guard ring model and combined with the orthogonal experiment method.In this paper,the CAE numerical simulation technology is used to take the fan retaining ring as an example and verify the validity of the wind protection loop model with the help of Moldflow software.Based on the simulation model,the influence of each process parameter on the warping deformation was studied through single-factor experiment.With minimum warping deformation as the goal,the injection molding process was preliminarily optimized,and the process parameters combination under the single factor variation experiment was simulated and verified by Moldflow software.After determining the level of factors,the orthogonal experiment with 5 factors and 3 levels is arranged according to the corresponding orthogonal table,the results were analyzed by range and variance.The results showed that The result of orthogonal experiment is better than that of single factor experiment,the relationship between the process parameters and warping was as follows: dwell time> dwell pressure> melt temperature> die temperature> injection time.The optimum process combination is established: temperature 40 ?,melt temperature 300 ?,injection time 1.2s,holding pressure 100 MPa,holding time 10 s.Under the condition of controlling the optimal process parameters,the change of glass fiber content was analyzed by simulation.The result shows that the warpage of the plastic part is the smallest when the glass fiber content is 25%.Based on the process optimization,the structure of the plastic parts is optimized by arranging the stiffeners and changing the wall thickness of the plastic parts.The structural optimization results are as follows: the wall thickness of the plastic parts is 2 mm,three stiffeners and stiffeners are added in the four corners of the plastic part,The two right-angled edges of the stiffener are 16.6 mm and 8.3 mm,respectively,with a thickness of 4 mm,The spacing between the two stiffeners is 4 mm.The results of process and structure optimization show that the combination of orthogonal test and numerical simulation can reduce the warpage effect of the plastic parts obviously.The research method of this paper has certain guiding significance for the actual production of glass fiber reinforced thin-walled parts.