Recycling industry is now a huge driver of economic growth in most developed countries. As such the business case for recycling has already been proven. Unfortunately in Zimbabwe recycling has not been fully embraced as an economic activity; it is still considered a social activity. Recycling of PET bottles started in 1977 and therefore it has now become a lifelong activity.

The case for PET bottle recycling is two pronged;

  • Most PET bottles are used in food contact applications and are therefore designed for single use, the so called one way bottles. This results in high waste generation which is a huge problem to the environment. The fact that PET in not biodegradable compounds this problem further.
  • The second argument for PET bottle recycling is that PET material is too valuable just to be thrown away hence our too good to waste pay off line. PET material possesses fibrous properties which could be handy in fibre and textile applications.

The whole recycling process is therefore meant to harvest and extract the polyster fibre which is inherent in the PET bottle for use in other applications mainly textile industry but also back into bottling- the so called bottle to bottle. The other obvious advantages of PET recycling are as follows:-

  1. Direct employment throughout the entire recycling value chain especially at recycling plants.
  2. Income generating opportunities especially for youth in waste collection
  3. It presents opportunities of mainstreaming the informal sector into the recycling value chains mostly as raw material suppliers- the so called inclusive business.
  4. Reducing PET related pollution in the environment (see facts)
  5. Huge savings on costs and energy as compared to virgin material.

The Recycling Process
The PET recycling process is all about removing all forms of contamination such as PVC, other plastics, metals, mud, glues and oil in order to remain with 100% pure PET. This is in order to achieve the desirable quality from the end user view point.

Discarded post consumer PET bottles are recovered mainly by informal collectors and delivered to the recycling plant either as baled or loose. The bottles are usually collected from households, retail outlets, food courts, streets, events and functions, hotels and landfills. The PET collectors, harvesters or vendors are paid according to the weight and quality of the material they would have recovered. It is desirable that the material be sorted by colour and material at the point of generation or point of picking by the vendor.

The material is further sorted and graded by colour at the recycling plant to ensure quality consistence. The bottles are then pushed through a series of washing and scrapping processes using a combination of hot water and chemicals to remove all contamination such as mud, residues, lables, other plastics and glues. PVC is considered to be the biggest contaminant in PET recycling and therefore it is imperative to train the vendors on material identification and sorting before they start to collect. Petrecozim is already running this programme on all new vendors.

The closures and lids are also separated through the densification process as PET which is heavier will sink while other plastics like BOPP, HDPE, PP and LDPE will float. PVC should not be allowed into the washing system because it has similar properties to PET and therefore it mimics the behavior of PET material throughout the washing process. The bottles are granulated and converted into flakes. These flakes are further washed using a combination of water and chemicals to achieve high purity. The flakes are then dried and bagged for end use markets. There is an option to extrude and palletize the flakes before they are supplied to end use markets.

Uses of recycled PET
Recycled PET has many applications across a wide spectrum of activities. However five distinct broad applications stand out; being bottle to fibre, bottle to bottle, geotextiles, automotive applications, industrial strapping and sheeting.

  • Fibre – Fibre constitutes the biggest end use market for recycled PET bottles. Common end products include polyster carpets, fiber filling for duvets, pillows, launch suites, car seats, upholstery, fabric for t-shirts, fill for sleeping bags, fleece jackets, tennis ball felt etc.
  • Automotive components – Grills, roof racks, luggage racks, headliners, fuse boxes, bumpers and door panels.
  • News Bottles – New PET bottles for food and non food applications such as washing detergents as well as automotive and industrial liquids. The recycled content in new bottles varies from bottle to bottle depending on the application of the bottle. Already there is now as much as 25% recycled content being used in some countries for food grade applications. Bottle to Bottle PET recycling is considered the new driver for PET recycling going forward as the fibre market is now saturated.
  • Geotextiles – Sheeting for landfill lining, road stabilization and general construction.
  • Other– Industrial strapping, sheet and film etc.