9 August 2019

Polyurethane (PUR/PIR) insulation and recycling. How to effectively manage PU waste?

The subject of the meeting involved planned activities regarding the circular economy. PU Europe, bringing together representatives of the polyurethane foam industry, decided to work out a joint position on possible management methods of waste generated by the industry. The result of joint works is to create clear guidelines. It is worth looking closer at what current PU waste management looks like and how to do it effectively.

Recycling of polyurethane foams

The PU producers themselves currently meet the environmental requirements. It is about continuous pursuit to reduce production waste. As far as construction waste is concerned, the trend seems to be to produce prefabricated components finished to be assembled on a construction site and generate almost no waste. However, it should be remembered that in practice most buildings are not constructed from prefabricated elements, which will also become waste in the future. In order to recover as much of the raw materials as possible, appropriate procedures should be developed for both construction waste generated during assembly and strictly demolition elements.

 

Buying in PU waste as well as available technologies for recycling polyurethane foams currently offer a number of opportunities to effectively manage these types of processes. How can efficient processing and reduction of PU look like? Some possible solutions can be found below.

PU waste treatment

It is crucial that both production and construction polyurethane foam waste can be recycled and reused. Remember that this type of material does not rot, is resistant to mildew, has low thermal conductivity, and at the same time is characterized by low weight and high mechanical strength. So how can it be processed? Both construction and production waste can be the basis for new high-density boards, as well as profiles that effectively replace wooden and wood-chipboard elements. However, it should be remembered that as far as mechanical recycling is concerned, boards made of glued cuttings show lower thermal insulation properties than the finished product.

 

Appropriate processing of PU waste means that it can form the basis of façade elements and partition walls, as well as doors, window frames and kitchen benchtops, and even components of trucks and trains. One of the most effective methods to manage PU waste involves processing it into products for thermal and acoustic insulation of floors. Waste foam is then the basis of granules combined with cellulose and additives. Such insulation material is evenly distributed over the ground. The described solution allows, inter alia lower a floor height, which can make it easier to assemble doors and stairs.

Reusing of PU

It is worth noting that PU insulation boards are most often mechanically fastened, and thus it is possible to separate them from other structural elements in buildings as well as reuse. This applies especially to insulation and sandwich panels fixed in pitched roofs. However, this solution seems appropriate mainly for minimally invasive and relatively easy installation forms.

Recycling of steel from sandwich panels

By analysing the application of sandwich panels and currently used PU recycling technologies, it is impossible not to notice that steel is one of the most attractive resources found in these materials. It can be processed many times. However, it should be remembered that steel cladding can be removed and re-processed, although this is time consuming. On the other hand, there is a method of recovering this type of cladding in a special destructive device.

The future of PUR/PIR recycling

The described options are not all. In the near future, a special branch of recycling, i.e. chemical recycling, which uses technologies such as hydrolysis, aminolysis and glycolysis, can be developed, as well.

 

It should be considered that there is a possibility of using PU dust to produce new insulation and sandwich panels or a possibility of adding polyurethane foam waste to lightweight concrete, cement screed and façade cladding. All above elements allow being optimistic about PU recycling, hoping that all processing technologies will be in line with the spirit of ecology and energy efficiency.