Recycling of Plastics

The processes after plastics are thrown into recycling bins:

 

There are two types of plastic recycling: mechanical and chemical.

 

Mechanical recycling: after removing other materials such as glass and metal that are found together with waste plastics, plastics are separated according to their types because each plastic type is recycled using different methods based on its chemical composition. Dried plastic pieces are melted by heating them in machines called extruders. The molten plastic is shaped with the ends of the machine. The semi-fluid plastic that comes out of the machine is cooled, then completely solidified and sized by cutting it into desired sizes.

 

Chemical recycling: It is a new technology used for plastics that are difficult to recycle or economically harmful to recycle mechanically. Three different methods are used in chemical recycling: purification, depolymerization, and raw material recycling. In the purification method, plastics are dissolved using suitable solvents according to their types. Thus, plastics are purified from foreign materials and other waste that are insoluble in the solvent. In the raw material recycling method, pyrolysis, gasification, or hydrothermal treatment is used. In hydrothermal treatment, plastics are reacted with hot pressurized water and after this process, monomers and different chemical substances are obtained from the plastic.

 

Recycle and Win...