Method for recycling waste generated in the production of fiberglass-reinforced plastic

Currently, the global market volume of polymer composite materials is increasing, the most widely used of which is fiberglass. A significant associated with large-scale production and application of these materials is the inevitable generation of waste, exerting a negative environmental impact. To address this issue, mechanical recycling of fiberglass waste is proposed, involving selective grinding in an impact-centrifugal mill followed by mechanical classification of the ground products. The aim of the work is to analyze the fractional composition of fiberglass waste recycling products as a function of the mill’s operational parameters. An experimental setup was designed and implemented to investigate the mechanical recycling process. Fiberglass waste (Depol S-180 PT) generated by Polotsk-Steklovolokno Company was processed. The rotation frequency of the mill’s rotor was varying in the range of 1200–3000 rpm. The resulting products were sieved into fractions, followed by measurement of fiber lengths in the fibrous fraction. The fiber surfaces and classification products were examined using optical microscopy at 50–500x magnification. The results demonstrate that the mechanical processing enables separation of the fibrous fraction from fiberglass waste, with its proportion in the ground products directly correlated to rotor speed. The optimal rotor speed was determined to be 2400 rpm, yielding the maximum fibrous fraction with the highest proportion of fibers (12–18 mm in length). However, mechanical classification failed to achieve complete separation of fibers and polymer matrix particles. Agglomerates formed during sieving (mesh size: 0.045–0.5 mm) obstructed fiber and particle passage through the sieve surface.