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;
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:-
The Recycling Process
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