Why is recycling plastic so difficult?

"We must act upstream on plastic products (especially packaging) that present more obstacles to recycling"

Thermoplastic polymers are in theory all recyclable with an industrial process that, in extreme synthesis, consists in a sequence of cycles of shredding and washing of the plastic waste to obtain flakes, or confetti, or powders in individual polymers, which are then extruded again. The "delta" between collected material and actually recycled material is however remarkable (only 50% 60%) and raises the question of acting upstream on those types of plastic products (especially packaging) that present greater obstacles to recycling, redesigned to combine current performance requirements with recyclability or, better still, to replace them with reusable ones.

In fact, downstream of the collection (especially urban even when differentiated) a complex and expensive preliminary processing is necessary, that is, the selection to obtain from a flow of mixed plastic packaging "products" homogeneous by polymer matrix and type.

This operation encounters objective limits (multilayer, multipolymer, too small or too dirty, polymers present in the collection in quantities too scarce for an industrial management), which make recycling of plastic so complex and expensive.