Polyurethanes are recycled in 2 basic and different ways: The first method is mechanical recycling, in which polyurethanes are used as resized polymers. In the second method, polyurethane is chemically recycled and decomposed into different chemical compounds. Always a part of the products produced by the companies as disposable waste causes a waste of their capital and energy. This issue causes an increase in the demand for recycling waste and low-quality products into consumable materials. If manufacturing companies do not find a way to recycle and reuse their waste, they will soon turn into a huge garbage dump, or perhaps throw away a huge amount of their capital, which will have harmful environmental effects.
Like many polymers, a wide range of polyurethane products can be recycled and reclaimed from the stream of destruction and conversion to waste and regain part of their intrinsic value. The general public and ordinary people are familiar with the recycling of thermoplastic products such as plastic bottles and everyday containers on the street. But maybe these people are not very familiar with the recycling of thermoset polymers, of which polyurethane foams are one of its types, and their shape cannot be changed by heating.
:Examples of products obtained from recycled polyurethanes
Rebounding
Nearly 500,000 tons of recycled polyurethane waste was used in 2012 for the construction of Rebandang substructure, which is used as the bottom layer of the carpet.
Mattress making
In America, many soft foam wastes are used as fillers in mattress making.
Recycling to raw materials
A factory in Michigan recycles about 70% of the polyurethane foam waste from its contracting party’s automotive industry into polyurethane raw materials.
Polyurethane recycling methods
Polyurethanes are recycled in 2 basic and different ways: The first method is mechanical recycling, in which polyurethanes are used as resized polymers. In the second method, polyurethane is chemically recycled and decomposed into different chemical compounds.
Methods of mechanical recycling of polyurethanes
- Flexible polyurethane foam rebounding (soft foam)
- Re-grinding or pulverizing
- Adhesive press and connection of polyurethane foam particles
- Compression molding of polyurethane foam particles
Methods of chemical recycling of polyurethanes
Glycolysis
In this method of chemical recycling of polyurethanes, polyurethane materials that need to be recycled are combined with large amounts of diol under high temperature and cause a combined chemical reaction and the production of new types of polyol. This type of manufactured polyols while maintaining the properties and performance of the original polyols are used as raw material for making various polyurethane foams.
Hydrolysis
In this process, as a result of mixing recycled polyurethane particles with water, the chemical reaction of hydrolyzation produces another type of polyols and chemicals that are sometimes used as intermediates in the production of polyurethane systems.
:Pyrolysis
The pyrolysis process, which refers to the disintegration of a compound due to heat, is used in the chemical decomposition of polyurethane foam particles under a free oxygen environment to break and decompose the main structures and produce gas and some petroleum derivatives.
Hydrogenation
Hydrogenation, which refers to the act of converting materials into hydrogen, like the pyrolysis process, produces gas and petroleum products from the combination of polyurethane materials with hydrogen under pressure and heat.
