Recycling Polyethylene Terephthalate or PET

PET is a very versatile plastic which belongs to the polyester family. Although PET was widely used in the 1950s in the textile industry (as yarn), it mainly gained popularity in the 1980s through its use in beverage packaging and packaging film.

PET bottles are usually produced in two stages; PET granules are first injection moulded to produce a preform (a very small bottle) which is then inflated at temperatures of around 100°C into a real bottle.

PET bottles were originally produced with one layer (monolayer). However, it is a well-known fact that all plastics are gas permeable. With monolayer PET bottles, the carbon dioxide gas content of soft drinks gradually decreases and oxygen permeation and light gradually alter the flavour, odour and colour of the drinks. PET bottles therefore had to be redesigned to reduce such external contamination by using some sort of buffer (often referred to in technical jargon as a “barrier”, hence “barrier technology”). A barrier of three to five different plastic layers (multilayer) made up of PET and EVOH (Ethylene Vinyl Alcohol) minimises oxygen permeability. External coatings are also sometimes added.

This barrier technology obviously doesn’t make it any easier to recycle PET bottles. However, Socaplast is specialised in distinguishing between the various mono and multilayer waste streams.

Socaplast shreds, grinds and granulates PET bottles (post-consumer and production), sprue fragments, preforms, flasks and films.