Study On Forming Process And Properties Of Parts Based On Mask Exposal Stereolithography

The mask exposal stereolithography parts are difficult to meet the high performance requirements in many fields.An experimental platform is set up and the molding process and part performance are studied.The properties of the parts are improved by the optimization of the molding process parameters and the post-processing technology.By studying the changes in the properties of the parts in different environments,the use of the injection is obtained.Meaning matters have certain guiding significance for production practice.First,a single factor experiment of layer thickness,exposure time,bottom exposure time,bottom layer number,round wait time and stratification direction is carried out.The influence of single molding process parameters on size accuracy,surface hardness and bending strength is studied.The size accuracy and table of the performance index are screened.Surface hardness and bending strength have the greatest influence on the molding process parameters.Secondly,the multi factor orthogonal test was carried out to study the influence of the coupling of various molding process parameters on the size accuracy,surface hardness and bending strength.The parameter optimization was carried out by the range analysis method,and the optimum combination of parameters was selected,and the influence of the parameters on the performance of the parts was arranged.Order,so as to facilitate the actual production of the advantages and disadvantages of each parameter.The optimal parameter values of the dimensional precision are composed of the layered thickness 0.15 mm,the exposure time 25 s,the round wait time 20 s,and the parameter combination reduces the relative size error from3.55% to 1.15%.The optimum parameter values of the surface hardness are as follows: the layer thickness 0.1mm,the bottom exposure time 40 s,the bottom layer number 2 layers,and the parameter combination increases the shore hardness from 82.2HA to 89.1HA.The optimal parameter values of the bending strength are composed of layered thickness 0.2mm,exposure time 25 s,the bottom layer number 2 layers,the layer direction is Y direction,and thecombination of this parameter value increases the bending strength 77.32 MPa to 89.25 MPa.Finally,the experimental research on the performance of the parts is carried out.The study shows that the tensile strength of parts will be reduced in wet or underwater environment,and it is reduced from 56.9MPa to 47.9MPa within 24 hours,and high temperature environment will reduce the bending strength,hardness and toughness of the parts,and the tensile strength of the parts can be increased from 56.9MPa to 62.7MPa for 3 hours at 60 C,and the bending strength is increased from 77.6MPa to 93.1MPa at the same time.After curing20 min,the bending strength can be increased from 77.6MPa to 95.7MPa.