Optical Properties Improvement of Recycled Polypropylene with Material Value Conservation Schemes Using Virgin Plastic Blends

Abstract

Repetitive implementation of material value conservation (MVC) in plastic packaging may lead to good quality plastic waste and high acceptance for secondary recycling. This makes the obtained recycled plastic pellets has good quality and can be used as an alternative raw material for new products. However, treatments and processing in the recycling processes can lead to the degradation of material properties and disrupt the recycled plastics life cycle to be used for new products with high specifications. Recycled plastics are certainly cheaper than virgin plastics, but they have low properties, contaminated, and are only used for low-value products. Therefore, a solution is needed for this problem. This study proposed mixing recycled and virgin plastic pellets to improve recycled plastics whose optical properties have been subjected to quality degradation. A series of tests were carried out on specimens and tested according to the American Society for Testing and Materials (ASTM) method. The optical properties tested were transparency, gloss, and colour. This study revealed that optical properties had an increasing trend along with the large number of virgin plastic pellets added to the blends. The optimal composition was found in the 50:50 composition of virgin-recycled plastic pellets to the 70:30 composition of virgin-recycled plastic pellets. These findings can be useful in improving the optical properties of recycled plastics. In addition, the widespread implementation of MVC can improve the quality of plastic waste and strengthen its acceptance for secondary recycling.