Table 5.

Potential improvements for PET, PP and PE (LDPE and HDPE) that could enable high quality recycling; based on the quality-related information from the surveyed plants.

Factors	PET	PP and PE (LDPE and HDPE)
Operational	Sorted into a sufficient quality for the production of recycled PET for bottle to bottle manufacture Colour separation and recyclates used in food contact packaging	Improvements are essential in plant process design (see section 3.2)
	High impermeability that allows the production of recycled PET with low levels of contaminants and presence of odours, compared with other polymers
Market	High demand for high quality materials from beverage bottle manufacturers	Development of additional markets for lower value fractions
Collection	Deposit Refund Scheme (DRS) in place for PET bottles; this limits the amount of non-PET bottles and also reduces the processing costs and ensures the homogeneity (Eriksen et al., 2019)	–
Recycling technologies	Not observed, recovering rates do not depend on the technologies employed	Improvements are possible but are subject very much to the market factor above
Recyclates' prices	Prices for food-grade recycled PET polymer are high whereas the price of virgin polymer is lower, since manufacturers purchase recyclates	–
Product design	–	Improvements in the choice of packaging materials and design-for-recyclability are essential (also stressed in Eriksen and Astrup, 2019)