How is Plastic Recycled?
1. SEGREGATION OF PLASTIC WASTE
The first stage of recycling plastic is to collect it from consumers and in order for this to be a successful as possible everyone needs to correctly identify and sort their waste into bins ready for collection. To simplify the process of identification plastics should have identification symbols embossed on to them with a number in that denotes the type of plastic the product is made from.
The most widely recycled plastic is PET / rPET / PETE which is the number 1 in the recycling triangle. This material is what most bottles and plastic containers found in supermarkets is made from and reputable suppliers such as Caterline Ltd in Manchester will manufacture products that is produced from at least 30% recycled materials (the Government directive)
Segregation of plastic waste is on the increase as consumers become more aware of what can be recycled and take more care and responsibility to ensure that their waste is disposed of in the correct way. A lot of retailers and councils are adopting initiatives to assist with the collection and recycling process such as clearly identifiable bins like the below examples. There is still a lot more that can be done by most though!
Clearly identifiable recycling in Bangkok, Thailand
2. SORTING OF PLASTIC WASTE
Sorting of plastics from other materials is carried out at Material Recovery Facilities and the sorting of different types of plastics for recycling is done at huge Plastics Recovery Facilities (PRF) where the plastics pass along conveyor belts and subjected to several sorting techniques to ensure removal of any potential contamination (such as metal) prior to to passing through optic sensors or sink flow separators which detect and isolate the different types of plastic
Waste reprocessing plant
3. WASHING PLASTIC WASTE
Once sorted, the plastic waste is hot washed to remove any residual waste left in the containers or labels etc that could affect the quality of the recyclate. Friction washers and Rotary washers ensure that oils and food traces are completely removed before the plastic can begin its new life.
4. GRANULATING / SHREDDING / EXTRUSION
Once thoroughly cleaned and sorted, the plastic is then put through granulating or shredding machinery which cuts the plastic into smaller flakes which are then ready for feeding into the extrusion line to be made into 'new' plastic sheet.
The extrusion process melts down the flakes at high heat and turns it into a liquid which is then forced through the extruder and converted to sheet. A video of this process which was filmed at the Caterline factory shows this process can be viewed at https://caterline.net/pages/environment
- Gary Briscoe