Regranulated PET used to produce bottles – how is it made and why is this process so important for the environment?

Mechanical recycling of PET packaging is basically about processing of post-consumer (i.e., previously used) bottles and other packaging made of PET into new materials that can be reused in production. This type of recycling is one of the most commonly used methods of recovering plastics and involves a number of steps to output high-quality recycled material, rPET.

Regranulated PET, also known as rPET, plays an important role in promoting a circular economy and reducing the negative impact of waste on the environment. The process of recovering regranulated PET from waste allows for the reuse of this valuable raw material, reducing dependence on fossil fuels and limiting the amount of waste ending up in landfills or oceans. In this story we will explain how this process works.

Steps of recovering regranulated PET

Recovering regranulated PET from waste such as used plastic bottles is a complex process consisting of many steps. Each of these steps plays a vital role in ensuring high-quality of recycled material that can be reused to produce new packaging and other products. Here are the most important steps in the process:

1. Selective waste collection and segregation

The process starts with the selective collection of PET bottles. Every user of PET bottles should ensure proper waste segregation. Plastics are usually placed in containers marked in yellow. The collected waste is then transported to recycling plants, where it is carefully segregated. It is usually done using advanced machines that sort waste based on type of material, colour and other physical characteristics.

2. Cleaning and removal of contaminants

Collected PET bottles are washed and cleaned of labels, glue residues and contents. This process ensures high quality and safety of the material for further processing.

3. Mill grinding and drying

After thorough cleaning, the bottles are ground into small flakes using special mills. Mill grinding is an important step because smaller fragments, called flakes, are easier to process and allow for obtaining a homogeneous regranulated material. Flakes are dried to remove moisture, which may affect the quality of the regranulate. The drying process takes place in special dryers that ensure appropriate temperature and air circulation.

4. Melting and filtration

Dry PET flakes are melted in special machines where they are heated to temperatures above 260°C. The melted polymer is then filtered to remove remaining impurities. The flakes undergo a degassing process to remove volatile impurities such as adhesive or paint residues. The flakes are heated and mixed in a vacuum, which allows unwanted substances to evaporate.

5. Granulation

The purified, molten PET polymer is ready for granulation. PET flakes are transferred to the extrusion process, which involves plasticizing them and passing them through special nozzles to obtain homogeneous granules. Extrusion takes place at high temperature, which melts the flakes and allows them to be formed into granules of uniform size and shape. After extrusion, the hot granules are cooled using cold water or air. Cooling is essential to ensure proper hardness and stability of the granules. The granules are then cut to the appropriate length using special cutters

6. Packing and distribution

The finished regranulated PET is packed and distributed to manufacturers of bottles, packaging and other plastic goods, where it is reprocessed into new products.

The importance of PET recycling for the environment

PET recycling and rPET production is of great importance for protecting the environment and promoting sustainable development. Here are the main benefits of using regranulated PET in bottle production:

• Reduced consumption of natural resources – the use of regranulated PET reduces the demand for new raw materials derived from fossil fuels, which contributes to the conservation of natural resources.
• Reduced waste dumps in landfills – PET bottles are one of the most commonly discarded waste types that can end up in landfills. Recycling bottles allows them to be reused and reduces the burden on the environment.
• Protection of marine ecosystems – the production of regranulated PET helps reduce the amount of plastic waste ending up in the oceans and seas, which protects marine life and contributes to the preservation of biodiversity.
• Reduced greenhouse gas emissions – the PET recycling process generates significantly lower greenhouse gas emissions compared to producing new plastic from fossil materials.

It is worth noting that PET recycling was the first plastic recycling process to be legally regulated in the European Union, which makes it the most developed and technically advanced in terms of quality and safety, as well as sustainable development.