采用非接触式预热对模压红外透镜雾斑的影响

Effect of non-contact preheating on fog spots of molded infrared lenses

非球面红外透镜模压成型时,通过提高成型阶段温度可缩短透镜压切时间,从而提高模压效率,但易在透镜表面产生雾斑,像造透镜不良。本文通过对透镜雾斑的形成机理进行分析,采用一种非接触式预热模压工艺降低透镜雾斑的形成,并在多站式模压机上进行模压实验,使用能谱仪对雾斑的元素进行检测和分析。在本次模压实验中采用非接触式预热方式,当预热间隙为1 mm时将成型温度由206℃提升至211℃,透镜表面无雾斑生成,并使压切时间缩短了21 s。实验结果表明,在多站式模压中采用非接触式预热方式,可以有效消除透镜雾斑的形成。检测结果表明,成型阶段透镜材料的挥发对雾斑的形成起主导作用。

When the aspheric infrared lens is molded,the lens press-cutting time can be shortened by increasing the temperature of the molding stage,thus improving the molding efficiency.However,it is easy to produce the fog spots on the lens surface,like a bad lens.Through the analysis of the formation mechanism of lens fog spots,a non-contact preheating molding process was adopted to reduce the formation of it,and the molding experiments were carried out on a multi-station molding press,in which the elements of fog spots were detected and analyzed by using an energy spectrometer.In this molding experiment,the non-contact preheating method was used to increase the molding temperature from 206℃to 211℃when the preheating gap was 1 mm,with no fog spots formed on the lens surface,and the press-cutting time was shortened by 21 s.The results show that the non-contact preheating method in the multi-station molding press can effectively eliminate the formation of lens fog spots.The test results show that the volatilization of the lens material in the molding stage plays a dominant role in the formation of fog spots.