This study used an in-house designed induction-aided hot embossing (IHE) setup to make polymer-based hydrophobic optical diffuser film for LED lights. Negative-featured micron sized V-shaped grooves (Width and depth −300 μm, angle −60°, adjacent distance-500 μm) were fabricated on the mold to develop the micro-textured mold required for the hot embossing via μ-WEDM. In this study, polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), and polycarbonate (PC) were used as working substrates. Initially, the parametric investigation was carried out by considering the four main parameters of IHE, i.e., embossing temperature-(T_e), pressure-(P_e), duration-(t_e), and deembossing temperature-(T_de). Parametric analysis shows that the height of the embossed micron-sized V-shaped-grooves on the polymer substrate significantly affects the embossed diffuser film’s wettability and lighting efficiency. Embossed PC diffuser film showed the highest height, WCA, and illumination in all parametric investigations. Finally, PC diffuser film was made with the optimal IHE parameters: T_e−225 °C, P_e−40 Kg cm⁻², t_e−600 s, T_de−30 °C. This set of settings resulted in a maximum V-groove height of 273.35 ± 4.71 μm and a 94.52% replication rate. Illumination analysis of embossed PC diffuser film (171×10² (lux)) compared to traditional/bare film (71×10² (lux)) revealed a 137.5% percentile gain in illumination. A laser-based optical system was employed for optical characterization, and the X-direction diffused light length on the white screen was measured. The best diffused light length was 109.35 mm for embossed PC diffuser film. To compare plain and embossed diffuser film lighting effectiveness, RGB photos captured by CCD-RGB camera were converted to HSI images to determine hue, saturation, and intensity. The intensity dropped most with embossed PC diffuser film. It shows that embossed PC diffuser sheet diffuses light better. Finally, wettability study showed that all embossed diffuser film surfaces are hydrophobic. Embossed PC diffuser film had the highest WCA (95.3°) and 27.71% higher wettability than bare film.

中文翻译：

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使用 μ-WEDM 制造的微纹理模具通过感应辅助热压印制造 LED 灯疏水性光学扩散膜：参数分析、润湿性研究和光学表征

本研究使用内部设计的感应辅助热压印 (IHE) 装置来制造用于 LED 灯的基于聚合物的疏水性光学漫射膜。负特征微米尺寸V形凹槽（宽度和深度-300μm，角度-60°，相邻距离-500μm) 在模具上制造，以开发热压花通孔所需的微纹理模具μ-线切割机床。在这项研究中，使用聚对苯二甲酸乙二醇酯（PET）、聚甲基丙烯酸甲酯（PMMA）和聚碳酸酯（PC）作为工作基材。_{最初，通过考虑IHE的四个主要参数，即压花温度-(T e} )、压力-(P _e )、持续时间-(t _e )和去压花温度-(T _de )来进行参数研究。参数分析表明，聚合物基板上压纹微米级V形槽的高度显着影响压纹扩散膜的润湿性和发光效率。在所有参数研究中，压花 PC 漫射膜显示出最高的高度、WCA 和照度。最后，采用最佳IHE参数制备PC扩散膜：T _e -225 °C、P _e -40 Kg cm ^-2、t _e -600 s、T _de -30 °C。这组设置导致最大 V 形槽高度为 273.35 ± 4.71μm 和 94.52% 的复制率。与传统/裸膜 (71×10 ² (勒克斯)) 相比，压花 PC 漫射膜(171×10 ² (勒克斯)) 的照度分析显示，照度增益提高了 137.5%。采用基于激光的光学系统进行光学表征，并测量白屏上的X方向漫射光长度。压纹PC扩散膜的最佳扩散光长度为109.35mm。为了比较普通漫射膜和浮雕漫射膜的照明效果，将 CCD-RGB 相机拍摄的 RGB 照片转换为 HSI 图像，以确定色调、饱和度和强度。压花 PC 扩散膜的强度下降最多。表明压花PC扩散板的光扩散效果更好。最后，润湿性研究表明所有压花扩散膜表面都是疏水性的。压花PC扩散膜具有最高的WCA（95.3°），润湿性比裸膜高27.71%。