My Science School

        We throw away millions of tonnes of plastics every year. Plastics make up about one-tenth of the weight of waste thrown away. Most of this is buried as landfill rubbish under layers of earth. Many plastics do not rot or break down naturally. This means that plastic rubbish will remain on our planet for a very long time.

       Recycling is the process of re-using waste materials to make new products. However, recycling plastics is complicated. Different types of plastic need to be processed in different ways. Some plastics can be melted and used to make more plastic products such as bags and bottles. Others can be made into fibres for clothing. Some can be burned as fuel in the recycling process.

Recycling process

Collection

Plastics are available in a number of forms for example plastic containers, jars, bottles, plastic bags, packaging plastic, big industrial plastics just to mention but a few. Due to their nature and availability, there are plastic collection centres and some business people have ventured into plastic collecting business as a source of income. Tons and tons of scrap plastic are collected and sent to a collecting yard where they are then packed and transported to plastic processing plants. Unfortunately, not all countries have the capacity to recycle plastic. Very few developing countries can actually recycle plastic. This means that, plastic waste is still a major problem to some countries in the world.

2. Sorting

The actual plastic recycling process starts with sorting of the different plastic items by their resin content and color. This process is also done to ensure all contaminates are eliminated. There are specially designed machines that help in sorting of the plastics according to their resin content. Then the recycling mill sorts the scrap plastic by symbols at the bottom of the plastics.

3. Shredding

After sorting the plastics, the next step is to cut the plastics into tiny chunks or pieces. The plastic bottles and containers are then ground and cut into tiny pieces or flakes. The heavier and lighter plastic flakes are separated using a specially designed machine. The separation process helps in ensuring that the different plastics are not put together or mixed up in the final product. Remember that different plastics are used to make different items.

4. Cleaning

After a complete separation, the flakes or chunks are then washed with detergents to remove the remaining contamination. Once the cleaning process is complete, the clean flakes are passed through specialized equipment that further separates the plastic resin types. The plastic flakes are then subjected to moderate heat to dry.

5. Melting

The dry flakes are melted down. They can be melted down and molded into a new shape or they are melted down and processed into granules. The melting process is done under regulated temperatures. There is specialized equipment designed to melt down plastic without destroying them.

6. Making of pellets

After the melting process, the plastic pieces are then compressed into tiny pellets known as nurdles. In this state, the plastic pellets are ready for reuse or be redesigned into new plastic products. It is important to point out that recycled plastic is hardly used to make identical plastic item or its previous form. It is in this pellet form that plastics are transported to plastic manufacturing companies to be redesigned and be used in making other useful plastic products.

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