Sandwich panels: how to produce low-index PIR panels with PUR conditions

Due to its greater thermal stability, better fire behavior and greater mechanical resistance, PIR sandwich panels (polyisocianurate) have become the preferred option for designers, engineers and architects to the detriment of PUR panels (polyurethane), predominant until now. The main difference between both types is that PIR panels have more isocyanate content and this gives better properties to the final material. Such properties are increasingly necessary due to a more strict regulation in terms of fire safety and the focus on energy efficiency.

To be more precise, PIR remains stable at temperatures ranging from -200°C up to +120°C, while PUR ranges from -150°C and +80°C. PIR has also greater dimensional stability and a wider range of temperature. As previously mentioned, the mechanical resistance is greater, at least 25%. Last but not least, PIR behavior in case of fire is safer since it is more fire resistant, creates less smoke when burnt and obtains B-s1,d0 classification.

PIR panels have a polyisocianurate core adhered to two blades, normally metallic, generally made of steel or aluminum. The product process, although very similar to PUR, has some specific requirements that makes difficult to produce them without the right equipment. PUR panels are produced at around 40-45ºC with no primer; PIR panels need temperatures of around 60 to 65ºC and a primer.

As a result, “many companies find it impossible to produce PIR panels with the same equipment they have for PUR”, says Mónica Fabra, Business Development Manager of Grupo Barcelonesa, specialized in polyurethanes. “In such cases, Grupo Barcelonesa proposes to customers Easy PIR system. This innovative system allows the production of low-index PIR using PUR conditions”, say the expert.

Easy PIR could mark a turning point for producers of sandwich panels since they would be able to satisfy the increasing demand of PIR panels without investing a lot in new equipment. It’s as easy as using this system in their 4 or 5 components version.