Preparation And Performance Study Of Condenser Lens Using Transparent Silicone Rubber

Solar concentrator system with refractive linear element, which used for spacecraftpower supply, has some advantages, such as low accuracy of light incident angle, highspecific power, low cost, et al, so it is widely concerned by scientists. The transparentRTV(room temperature vulcanization) silicone rubber becomes an important material forprojection lens because of its advantages of excellent resistance to high and lowtemperature, resistance to ultraviolet radiation, high transmittance and low density.In this paper, the107and231silicone rubber were used as raw materials, andPMMA(polymethylmethacrylate) and PC(polycarbonate) were used as contrast materials.The effect of temperature, air humidity and mold release agent on the solidification ofsilicone rubber were investigated and the processing parameters were optimized. Themechanical properties of materials were measured by tensile testing machine and ShoreA Durometer; the property of light transmittance was tested by ultravioletspectrophotometer, and thermal stability property for silicone rubber were analyzed usingthermogravimetric analysis(TGA). Finally, the solar energy collector system wasdesigned and prepared successfully using the best optimal projection lens materials,which purposed to analyze the condenser performance of projection lens.The optimum process of silicone rubber was given as followed: first of all, the colloid,catalytic and cross-linking agent were mixed fully; then the internal bubble in the colloidwas discharged completely in vacuum system; Finally, the colloid was solidified in mould,humidity was more than30%and the temperature was25±2℃.The transmission performance of107and231silicone rubber was excellent, and thetransmittance of visible light could reach92%or more when the its thickness was lessthan2mm. The thermal stability of107and231silicone rubber was also excellent, theirthermal decomposition temperature was about300℃or above,and the thermal stability of107silicone rubber was slightly better than that of231silicone rubber. However themechanical properties of231silicone rubber were better than that of107silicone rubber.When the catalytic amount was1%, its tensile strength could achieve0.76MPa, theelongation at failure was about196%, and shore hardness was more than21degrees. Finally the231silicone rubber was chosen to fabricate projection lens material.The light condensation performance of the lens was analyzed using the solar energycollector system. The rusults revealed that the geometric concentrating ratio of lens hadgreat effect on the condenser performance, when the geometric concentrating ratio of lenswas5, the condensing ratio could achieve3; when the geometric concentrating ratio oflens was4, the condensing ratio of the lens could only achieve2.