Utherm Next: the next-generation PIR insulation board

The challenge?

To date PIR insulation boards are not yet fully circular. Chemical recycling is the solution but at the moment this technology is not yet scalable for widespread use. However, the technology is evolving favourably.

The solution?

As long as a recycling process is not available, the only option is to compose insulation boards in such a way that future technology will make them recyclable. Meanwhile we keep looking for ways to make the board itself more sustainable.

We do this by:

• using 100% circular polyol
• making foam and aluminium facing easier to separate, thereby facilitating the recycling process
• adding a halogen-free flame retardant

In the past two years, R&D engineer Arno Verlee and process engineer Berre Borgonjon have spared no effort to help develop Utherm Next. It’s the only insulation board on the market containing 100% circular polyol, without compromising quality standards and insulation values. What’s more, as soon as chemical recycling on an industrial scale becomes an option, this insulation board will be fully recyclable.

A substitute for petroleum?

The major challenge for PIR insulation board manufacturers is to make them more sustainable and lower their so-called LCA (life cycle analysis). This value reflects the environmental impact of a product. Arno: “In the future, fossil fuels must be eliminated from our insulation boards. The foam of an insulation board currently consists of two chemical components, polyol and MDI, that use petroleum as a raw material. We carried out a raw material screening to identify more sustainable alternatives.”

MDI accounts for 60% of the foam layer but at the moment a more sustainable alternative is not yet available. Arno: “That is why we examined whether the polyol, which provides 30% of the foam layer, could be replaced with biobased or recycled content. Eventually we found one supplier of a circular polyol that consists of both recycled polyol and biobased material. The recycled polyol is sourced from recycled PET plastic. The biobased material is sugars from a restroom in the agro-industry. These ferment into a liquid molecule, which reacts with the PET to form a single entity.”

Circular polyol as an alternative

To determine whether the circular polyol was a viable alternative, Berre performed a series of tests on the production line. Berre: “A key parameter in the evaluation was the uncontrolled expansion of the board during production. This must be limited as much as possible and just one specific type of polyol possessed this characteristic. Late 2023 our team started producing and optimising the insulation board with the new polyol. First of all we had to develop the right technique to process the new raw materials into a quality foam. We succeeded in May.”

Halogen-free

Apart from the circular polyol, Berre also tested a more environment-friendly alternative for the classic flame retardant with halogens. “A halogen-free flame retardant was added to the circular polyol. Halogens include substances such as chlorine and fluorine, which are very noxious during combustion.”

Different protection layer facilitates recycling

A third adjustment that assures that Utherm Next will be fully recyclable in the future is the adapted protection layer (facer) on top of the foam layer. Arno: “At the moment the PIR insulation boards are not yet ready for recycling on an industrial scale because our production lines are not yet fitted with the proper technology. It is still under development but we’ll get there eventually. Meanwhile we are already working on ways to make our insulation boards easier to recycle. That is why Utherm Next now uses aluminium as a facer. That is easier to separate from the foam layer and provides better recycling results than the current multilayer facer.”

Improved foam layer

Berre was also in charge of testing the aluminium facer. “The facer gives stability to the insulation board and limits warping. The aluminium facer proved to be a good alternative and even brought an unexpected improvement. The foam layer now has a better fire rating: D instead of E/F. The facer makes it easier to spot imperfections in the foam layer. That is why it is crucially important to use the right process parameters so those imperfections can be avoided. A fine example of our pursuit of excellence through innovation and pushing boundaries.”

Arno’s research and Berre’s exhaustive testing ultimately resulted in a new product that already has a lower environmental impact while anticipating a future as a fully recyclable product.

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