Climate change is probably the most important and urgent crisis the world is facing.
Since 1990, CO2 emissions have increased by more than 50%, dramatically impacting Earth, changing precipitation cycles and temperatures. And if in developed areas global warming is endangering the economic infrastructure and individual sectors, in less developed regions, it is compromising the existential basis of large parts of the population.
In 2015, 196 Nations signed the Paris Agreement to reduce climate change risks and effects, undertaking to limit the temperature increase to 1.5°C through a series of regulations aimed at reducing emissions in the atmosphere and encouraging efficient use of energy. In parallel, Europe is working to be the first continent with zero climate impact by 2050.
Reducing energy consumption is the most efficient way to limit greenhouse gas emissions and ensure energy supply. In this context, polyurethane, thanks to its insulation properties, plays a fundamental role.
The two souls of polyurethane
Why is polyurethane so strategic for improving energy efficiency?
Because polyurethane is one of the most efficient and safe materials to maximize the efficiency of structures, home appliances, and vehicles, allowing the optimization of natural resources.
In particular, in the building sector, the thermal insulation of roofs, walls, windows, and pipes with polyurethane is the most effective method to keep the temperature constant, reduce energy consumption and waste, and reduce the number of energy escapes from homes.
In household appliances, in the same way, the use of polyurethane implies less energy for powering refrigerators, freezers, water heaters, and other similar equipment and less energy consumption.
Finally, PU in vehicles (employed for seating, steering wheels, cavity filling…) helps to reduce the weight of cars and trucks, with important effects on fuel savings.
So, if, on the one hand, polyurethane is essential to the energy transition, constituting a fundamental tool, on the other hand, it has an enormous limit: being of synthetic derivation, it is not bio-based nor bio-gradable.
However, in recent years, companies have invested a lot in search and development to find new and proper ways of polyurethane foam recycling, achieving excellent results.
Is polyurethane recyclable?
Various polyurethane foam recycling methods can be applied depending on the type of polyurethane to protect the environment while avoiding throwing away such valuable material.
For some companies, especially those producing sandwich panels, recycling of polyurethane foam coming from process waste represents a possibility to be greener and an important economic value: think that in Europe, for instance, the disposal costs of PU are around 300 – 400 €/ton.
The three main polyurethane foam recycling processes are:
- Chemical recomposition and reintegration as a polymer: Many companies, mainly related to Raw Material Suppliers, are investing in glycolysis or molecular cracking plants through which re-obtain the re-usable polymers from the molded products.
- Thermal valorization: polyurethane becomes an energy source, thanks to its high residual calorific value for incinerators, allowing the generation of new energy, effectively replacing fossil fuels.
- Mechanical reintegration: polyurethane is mechanically crushed or ground and then insert into the virgin raw materials.
Reintegration after maceration
This type of polyurethane foam recycling is commonly used in the production of insulation panels. The producers of this kind of panels, in fact, have to manage a percentage of processing waste ranging from 2% to 5% of the product itself. For them, the recycling of polyurethane foam is a strategic choice.
In this case, polyurethane is reduced to flakes or powder and is reintegrated into the polyurethane foam matrix.
For this kind of polyurethane foam recycling, Cannon has developed a specific process with proper equipment (re-integration module, dosing machine, and mixing head): the tests performed in our laboratory evidenced that the conductivity and the expansion of the foam with recycled polyurethane integrated, after proper preparation, are by far similar to that of foam without integrated material, and also the density is practically the same.
Due to the intrinsic characteristics of the material, the panels produced with embedded recycled polyurethane are optimal to be used in all cases in which the panel is exposed to water or humidity, sudden changes in temperature, and atmospheric agents.
