ICATAS23-A Study of Repetitive Recycling of Polypropylene Waste: A Quality Evaluation and Economic Assessment

Abstract

Plastic products play an important role in our daily lives. Many efforts have been directed during the past ten years towards reducing the amount of plastic waste polluting the environment. Mechanical recycling is one of the techniques for disposing of plastic waste. The plastic scrap is first collected, sorted, washed, crushed, and then converted into useful products through injection moulding or any similar primary shaping process. Polypropylene is a common thermoplastic that is listed as a food grade plastic being used to manufacture food containing products. Polypropylene could be recycled more than once without a significant reduction of its mechanical and physical properties. This paper presents a real case study that seeks to evaluate the economic benefit and product quality of repetitive recycling of polypropylene boxes up to five cycles. The results showed a clear reduction of the unit cost of the recycled plastic compared to a new part. The transparency of the recycled boxes decreased but remained acceptable till the fourth cycle. Tests proved that tensile properties were moderately affected by recycling. Hardness and density had slightly decreased at the fourth cycle.