Effect of repetitive recycling on the optical properties of polypropylene based on material value conservation paradigm

Good quality of plastic packaging waste has the potential to be recycled, as it can be used as raw material for the next packaging products. Recycling is preeminent due to the grave necessity of decreasing plastic production rate, especially for packaging industries which are known to use more plastic compared to other sectors. Material value conservation is a new paradigm which can be implemented through a new category of design for recycling in order to avoid value degradation. Implementations of this paradigm has produced better quality processed plastic waste with higher selling price. Applied with this paradigm, recycled plastic pellets can be a viable alternative as raw material based on its mechanical properties, even after the 8^th stage of recycling. This study aims to reveal the effect of repetitive recycling on the optical properties of polypropylene with implementation of material value conservation paradigm, to strengthen previous evidence of the implementation of the material value conservation paradigm on plastic packaging whether repetitive recycling plastic packaging can be a viable alternative as raw material based on its optical properties. Optical properties observed in this research were based on the American Society for Testing and Materials (ASTM) standards, which are consisted of colour (ASTM D2244), gloss (ASTM D2457) and transparency (ASTM D1746). The result of this study indicated that even after the 8^th stage of recycling, plastic pellet of polypropylene still can be a viable alternative as raw material based on its optical properties, with more attention on transparency property.