Research And Application Of Microcellular Injection Molding

The shrinkage properties of the resin gave rise to the limitations of plastic products,the current environmental issues and production safety problem increasingly prominent,and a series of problems,microcellular plastics injection molding technology can reduce weight to a great extent,saving energy and reducing consumption,stable parts size,so the new technology has a broad application field.Based on polypropylene?PP?as raw material,supercritical fluid as physical foaming agent to the preparation of microcellular foam plastics,through CAE simulation,experimental design and material testing technology,research on the influence of forming material performance on supercritical fluid,talcum powder and forming process parameters;Using the method of experimental design and optimization,response prediction model is set up and look for the optimal process parameters combination.Finite element simulation analysis and material testing technology study the effect of the physical foaming agent?CO₂ and N₂?and talcum powder additives to the mechanism of microscopic pore morphology,macroscopic mechanical properties and apparent quality.Results show that under the same process conditions,N₂ bubble hole and warping is smaller than CO₂.Talc is helpful to improve the mechanical properties of parts.Experimental control variable methodresearch the effect of the parameters?gas injection quantity,injection temperature,injection rate?on the mechanismof bubble structure,mechanical properties and plastic molding quality.Researche shows that maintain the little injection time and higher injection rate can get a good bubble structure whichis obtained by changing the melt temperature.The experimental scheme established by FFD to get the main influence parameters for the response?aperture and warping?is per cubic meter of gas nucleus,initial concentration,melt temperature and cooling the gas temperature;central composite design research objective factor and the interaction between the influence law of the response,respectively establish mathematical relationship model of aperture and warp,study the influence law of process parameters design of aperture and warp;Based on process parameters optimization method,through Multi-objective optimization of the linear weighted sum method to get the optimal scheme of microcellular injection molding.Study the influence of different injection molding stages?gas control process,filling process?and temperature on the forming quality of foamed door trim panel on the above results.The influence mechanism of the process on the microstructure distribution and the apparent mass was obtained.