Impact of thermomechanical reprocessing conditions on polypropylene composites made from automotive waste parts: A path to a circular economy

Abstract

This work focused studying waste car bumper samples and their processing by re-extrusion-injection. Car bumpers are composed of crystalline phases of polypropylene (PP), talc, and amorphous ethylene propylene diene monomer (EPDM). The recycled material's thermal, mechanical, and structural properties depend strongly on the process used for extrusion and injection and the crystalline phases formed during the heating process. The FWHM of the x-ray diffraction patterns was used to study the recrystallization phenomenon in PP, and the result was in direct correlation with the Differential Scanning Calorimetry (DSC) results. The remaining micro paint particles from the bumpers involved in the recycled extrusion-injection process affect the mechanical properties, and their size and toughness could affect the injection. Removing these particles could improve the mechanical properties of the recycled PP. Car parts based on polypropylene can be recycled for the automotive industry to produce the same type of products and even for other areas. A methodology and metrology can be developed to understand the chemical composition and its relationship with the properties of PP-based materials. This could lead to finding new applications in different fields and promote the development of a circular economy.

A Comprehensive Outlook of Scope within Exterior Automotive Plastic Substrates and Its Coatings

“…The recipe being a trade secret has been an obstacle, as the exact composition of TPO/PP is unknown to many. The knowledge of physicochemical properties is a major factor in addition to the operating conditions of the recycling process [26]. While the European commission regulation on end-of-life vehicles (ELVs) have established goals for a recyclable system, the United States Department of Energy proposed a plan for a 95% recycling rate target for automobiles, which includes metals, plastics, and other materials.…”

“…To that extent, researchers have worked with environment aging and oxidation processes [49][50][51]. Recently, bumpers from automotive waste were recycled via re-extrusion-injection and it was observed that the removal of micro paint particles is a critical factor for improving the mechanical properties, in addition to non-damp storage conditions [26]. In another case study by Guo et al, the paint removal process was carried out via plastic shot peening followed by the addition of nano-montmorillonite, virgin PP, recycled PP, and a compatibilizer.…”

Correlation of structure, rheological, thermal, mechanical, and optical properties in Low Density Polyethylene/Linear Low Density Polyethylene blends in the presence of recycled Low Density Polyethylene and Linear Low Density Polyethylene

“…Just in 2019, it was reported that the global plastic market had stretched to 368 million tons, and it is projected to rise to 417 million tons by 2030 and double by 2050. [1][2][3][4][5][6][7] The linear global plastics economy, with its "take, make, use, and waste" approach, is responsible for the majority of plastic products being discarded without repurposing after reaching the end of their life. Also, it is worth mentioning the production leftovers, which take up a notable amount of total plastic waste.…”