Surface quality of plastic parts effect on metallization coating by PVD method

Physical vapor deposition (PVD) is a very common method used for metalized coating of plastic parts. This study deals with the light reflection of plastics, which are widely used in the lighting industry, depending on the surface quality while metalizing aluminum coating. In the automotive lighting industry, plastics are preferred because they are lightweight, suitable for mass production, and create cost advantages. Light reflection is ensured by coating aluminum on plastics with the PVD method, which is suitable for mass production. Not every material may be suitable for aluminum coating. For this reason, ABS and PC materials are mostly preferred as reflector structures in the automotive lighting sector. These two materials have been compared due to their differences in mechanical properties such as abrasion resistance, hardness, different thermal resistance, and so on. The aim of this study is to examine whether the products produced by the PVD coating method, which is the most suitable method for coating plastic with aluminum in mass production, depend on the surface quality in fulfilling the lighting functions. PC and ABS materials were selected as 2 different materials that are frequently used in the field of lighting in the automotive sector, the surface of the plastic was sanded with 3 different grit numbers of 400 sand, 600 sand, and 1000 sand sandpaper, and the aluminum coating was performed in PVD machine. While the plastic was coated with aluminum in the PVD machine, the metallization process was applied simultaneously at the same time. The effect of the surface quality was measured optically by photometry according to the reflection of light from 30 meters and the reflection values was compared. As a result of the use of finer abrasives, the dispersion of light in PVD coating is reduced due to abrasions on the surfaces. It was observed that the surface of the part was close to smooth and fulfilled its function. Since the hardness and abrasion resistance of PC material is better than ABS material, it was observed that PC material was less abraded when the surfaces were sanded with different abrasives. Accordingly, after PVD metallization with aluminum coating, it fulfilled its reflective function as a reflector better than ABS material. In line with the results obtained, in designs such as reflectors that provide reflection of lighting, hard materials are preferred and used more frequently because they are more resistant to abrasion. This creates inputs for process and product molding to prevent the deformation of surfaces in future projects.