Polyurethane rigid foam boards (PUR/PIR) are organic insulation materials made from synthetic raw materials and belong to the group of foam plastics. Polyurethane is made from petroleum products and, in some cases, from renewable raw materials such as potatoes and corn. The chemical reaction of liquid raw materials and the addition of propellants creates a rigid foam that gets its insulating effect from the inclusion of air or propellants in the inflated cells. Polyurethane is resistant to aging and mold, rot, and rotting. It has a low bulk density, which has a comparatively disadvantageous effect in terms of summer thermal insulation as well as sound insulation.
The production is very energy-intensive and, although partly made of natural products, the material cannot be recycled or composted. Toxic gases can be released during combustion. Polyurethane is often used mainly because of its very good thermal insulation properties, which are further improved by the aluminium lamination. However, aluminium-laminated insulation boards are diffusion-tight and therefore cannot be used for vapour-permeable roof structures. The dimensionally stable panels are available in thicknesses of 20 - 300 mm.
Source: bauwion
