摩擦系数对非球面玻璃透镜模压成型的影响

Influence of Friction Coefficient on Glass Molding Process

研究了非球面透镜玻璃模压成型过程中玻璃-模具界面的摩擦行为对成型透镜质量及成型效率的影响。针对不同的摩擦系数,对玻璃模压过程进行了热-机耦合的有限元模拟。结果表明:(1)随着摩擦系数的增大,透镜表面的等效应变减小,而透镜内部的等效应变明显增大,合模时间变长;(2)随着摩擦系数的增大,透镜内的残余应力的最大值增大,残余应力向透镜表面集中;(3)摩擦系数对透镜成型后的面型偏差影响很小。因此,为了降低透镜成型后的残余应力和提高成型效率,应减小模具和透镜接触面上的摩擦系数,但无法通过改善接触面上的摩擦情况来减小面型偏差。

Influences of glass-mold interface friction on quality of molded lens and molding efficiency are studied in the present research. FEM simulation is conducted on glass molding process(GMP). The following results have been found:With the increment of friction coefficient,(1)equivalent strain at the surface of the lens decrease,whereas equivalent strain at the center of the lens increase,and time to close the mold is prolonged;(2)maximum residual stress increase,residual stress concentrate on lens surface and;(3)the deviation of lens profile is not significantly influenced by the change of friction coefficient. Thus,to decrease the residual stress and minimize the mold-closing time,the friction coefficient on the glassmold surface should be minimized,but the deviation of lens profile cannot be optimized by improve friction condition.