Investigations into the production of achromatic lenses by two-component injection compression molding of transparent plastics

透明塑料二组分注射压缩成型生产消色差透镜的研究

• 批准号: 432469470
• 负责人: Professor Dr.-Ing. Dietmar Drummer
• 金额: --
• 依托单位: Lehrstuhl für Kunststofftechnik (LKT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/432469470?language=en
• 关键词: Investigations; into; production; achromatic; lenses

Compared to many optical grades of glass, plastics have a high dispersion. This means that the refractive index of the material decreases more strongly with increasing wavelength. As a result, different wavelengths of light (light colors), which are focused by an optical lens, have different focal positions. This leads to image errors and blurred images, which is why imaging optics are usually composed of several combined lenses. In illumination optics, the dispersion is shown by a color veil on the edge of the light cone.By combining two lenses made of materials with different dispersions to form an achromatic lens, this chromatic aberration, can be reduced, resulting in a significant increase in imaging performance. To improve image quality, plastic lens systems are usually assembled from several lenses. This requires the production of several components, exact positioning and further assembly steps.The project therefore focuses on injecting a second component onto a preform with low warpage and shrinkage to produce an achromatic lens from different transparent plastics. Possible plastics for the combination are polycarbonate (PC) and poly(methyl methacrylate) (PMMA). In addition to reducing further processing and assembly steps, two-component injection molding also increases transmission by reducing reflections at the interfaces.From the application of an achromatic lens, the general derivation of a production strategy for low-shrinkage and low-warpage two-component injection compression molding with large contact surfaces is to be carried out in the research project. In addition to optics, this knowledge is relevant for numerous other applications. Nevertheless, the prerequisites for this two-component injection moulding of optical components are particularly challenging. The second component must be injected onto the preform with very little shrinkage, the injection process of the second component should not deform the first component surface and sufficient adhesion of the two plastics over a large surface must be ensured. These points are to be achieved by an adapted injection compression molding process. An adapted compression of the melt in the process by means of embossing should reduce subsequent shrinkage of the injected component as far as possible. The influences of the process parameters on adhesion, shrinkage, the shape of the interface and the refractive index as well as the component properties are systematically investigated.

与许多光学等级的玻璃相比，塑料具有高色散。这意味着材料的折射率随着波长的增加而下降得更厉害。因此，由光学透镜聚焦的不同波长的光（光颜色）具有不同的焦点位置。这会导致图像错误和图像模糊，这就是成像光学器件通常由多个组合镜头组成的原因。在照明光学中，色散通过光锥边缘的色纱来显示。通过将两个由不同色散材料制成的透镜组合成消色差透镜，可以减少这种色差，从而显着提高成像性能。为了提高图像质量，塑料镜头系统通常由多个镜头组装而成。这需要生产多个部件、精确定位和进一步的组装步骤。因此，该项目的重点是将第二个部件注射到低翘曲和收缩的预成型件上，以用不同的透明塑料生产消色差透镜。适合该组合的塑料有聚碳酸酯 (PC) 和聚甲基丙烯酸甲酯 (PMMA)。除了减少进一步的加工和组装步骤外，双组分注塑还通过减少界面处的反射来提高传输率。研究项目将通过消色差透镜的应用，全面推导具有大接触面的低收缩和低翘曲双组分注塑压缩成型的生产策略。除了光学之外，这些知识还与许多其他应用相关。然而，这种光学元件的双组分注塑成型的先决条件特别具有挑战性。第二组分必须以非常小的收缩率注射到预成型件上，第二组分的注射过程不应使第一组分表面变形，并且必须确保两种塑料在大表面上充分粘合。这些要点将通过适当的注射压缩成型工艺来实现。在加工过程中通过压花对熔体进行适当的压缩应尽可能减少注射部件的后续收缩。系统地研究了工艺参数对附着力、收缩率、界面形状和折射率以及部件性能的影响。