Penentuan Komposisi Campuran Cat Bakar Akrilat untuk Aplikasi pada Media Plastik Polipropilena

Abstract

Car parts that need paint coating consist of 2 main substances, metal and plastic. Metal car body needs acrylic paint types whereas polypropylene plastic car bumper use polyurethane paint, so color matching needs to be carried out between the two materials. In terms of price, as well, polyurethane paint is more expensive than acrylic paint. Based on these conditions, application of acrylic paints onto both metal and plastic surfaces has been studied to reduce production costs and produce better color closeness between the two parts of the car. Acrylic paint was mixed with hardener, which is commonly added in polyurethane paints, with varied ratios and was tested for its coating qualities with hardness and adhesion on both types of materials as the test parameters. The proximity of colors had also been tested for grape red pearl metallic color. The results showed that the appropriate compositions for hardness test were 1:0.25 and 1:0.20 ratios of paint and hardener material, the test used Mitsubishi type HB up to F pencil size. The composition that met the adhesive power test were 1:0.35, 1:0.30, and 1:0.25 ratios of paint and hardener material, all three had adhesion power of 100/100 unpeeled paint coating. Color matching test indicated that the appropriate composition was 1:0.25 ratio of paint and hardener material with delta E value <0.5. It can be concluded that the composition producing painting quality that fulfil the three parameters are paint-hardener material 1:0.25.