Development of chemical wash processes as advanced pretreatment in plastic recycling

Subtitle:Ontwikkeling van chemische wasprocessen als een geavanceerde voorbehandeling bij de plasticrecyclage

The demand for plastic packaging continues to grow due to their exceptional functional performance, including among others, oxygen, moisture and light barrier, printability and food compliance. However, recycling rates of plastic packaging are still low due to the lack of infrastructure in collection and sorting, as well as their inherently complex structures including the presence of multilayers, additives, inks, among others. In European countries, plastic packaging is mainly recovered through open-loop mechanical recycling processes because contamination from both the production and use phase impedes closing the loop for these plastics in high-value applications. For example, the presence of ink adversely affects the optical and physicochemical properties of recycled plastic films. Furthermore, plastic packaging can consist of a combination of different types of polymers, each with their own specific performances in order to obtain superior functionality related to preservation of e.g. food. However, differences in the processing properties of polymer layers used in a multilayer structures impede recycling as they cause incompatibility issues during melting, typically between polyolefins and heteropolymers. Similarly, additives are ubiquitously used in plastics to improve their functionality. However, they are not always desirable in their U+2018second lifeU+2019 and are a major bottleneck for recycling. Within this thesis, chemical washing processes such as dissolution-precipitation, delamination and deinking are developed as a pretreatment step to facilitate recycling of plastic waste. Theoretical aspects of these chemical wash processes are given and they are assessed in terms of technical, economic and environmental feasibility which are crucial parameters towards closed-loop recycling of plastic waste.

ISBN:9789463575133

Publication year:2022

Accessibility:Closed