PET RECYCLING TO MANUFACTURE POLYESTER STAPLE FIBER

Nowadays, PET bottles are the global number one in beverage packaging. More than 400 billion plastic bottles come on the market every year and PET is becoming increasingly valuable as a recyclable raw material used in the production of beverage bottles. Thus, it is important that all of the production steps applied for the manufacture of your PET bottles is made sustainable for the future.

The gentle treatment of resources and economical use of materials are a must when it comes to sustainable production. Valuable raw materials such as PET must be processed as efficiently as possible while still tapping into every way of saving costs. The PET manufacturing and production process allows for the application of a sustainable approach which can optimally combine environmental awareness and cost effectiveness: the bottle-to-bottle recycling concept.

Bottle-to-bottle recycling plant efficiently recycles used PET bottles and the recyclate is then reused in the food and beverage industry as recycled PET (rPET). The complete process comprises the cleaning of the used PET bottles and the treatment of the recyclate so that the end product – which could come in the form of flakes, pellets or preforms – can meet the highest quality requirements after the recycling process. European and American certificates (e.g. FDA) and a number of different corporate approvals, all confirm the high quality of the recyclate for direct use in containers which come into direct contact with foodstuffs.

Polyethylene terephthalate (PET) is one of the most widely used plastics today. PET bottles are ubiquitous in our day-to-day lives–one has to just look around to spot a PET bottle containing mineral water or soft drink or used for other applications. With such wide usage (in 2015-16, ~ 900 KT of PET was used in India), comes the question, what happens to the PET bottles after use. Are they recyclable? If so, how can they be recycled? What can be made out of recycled PET? How much of PET consumed in India ends up being recycled, in a given year?

PET bottles, post use, still carry a lot of value, and recycled PET (r-PET) can be used in a wide variety of applications. This makes post-consumer PET bottles a very sought after item by waste collectors. Discarded PET bottles fetch waste collectors Rs 14-15/kg. These bottles are bought by kabadiwallahs or waste traders, who employ people to segregate, sort and further sell it to large vendors or recyclers. The caps, neck rings, labels (non-PET components) are removed, and the bottles are shredded, washed, and sold as what is called ‘washed flakes’. These washed flakes are then used to make (predominantly) polyester fiber, which is used as filling material for cushions, pillows, and converted to fabrics for use in clothing, upholstery, etc. These end products sell at anywhere between Rs 50-110/kg; the market for r-PET products is quite large. There are 40+ large manufacturers across India who use r-PET as raw material. The PET recycling business can be estimated (roughly) to be around Rs 3,000- 4,000 crore in a given year in India.

Worldwide, PET-bottles more and more replace glass bottles in the beverage and food sector. The success of PET in comparison to glass is based on several economic (and environmental) advantages.

On the one hand, the production of PET is less expensive and energy consuming than the production of glass. Secondly, the light weight of the PET-bottle makes it easier for merchants and consumers to handle the bottles and crates. It saves energy during transport, particularly on long distance haulage. Finally, PET offers more or less the same material properties as glass regarding hygiene, taste and gas impermeability.

The negative impacts of PET-bottles in recent years result from their use as nonreturnable beverage containers leading to a dramatic increase of beverage container waste. But even here, changes are on the move, particularly in industrialized countries, where PET-bottles enter more and more the existing returning and refilling schemes. Apart from returning and refilling, recycling of used PET-bottles is also possible, and will be an interesting option especially for developing countries, where refilling schemes are not in place or economically unfavourable.

PET is the abbreviation for polyethylene terephthalate. It is polyester (chain of individual “ester”) which is formed by polycondensation of two types of monomers called ethylene glycol and purified terephthalic acid.

Principle of polycondensation