Polyurethane rigid foam,due to its closed cell structure,uneffected by moisture,enjoying long life thermal insulation and hygenic properties,has been the favorite choice among the thermal insulation
materials.With the additives of halogen free products increasing the resistance to combustion of PUR foam it had been classified as DIN 4102 B2 flame retardent.
The increasing demands by concerns on fire behaviour in building codes,researches have been carried out by the manufacturers of raw materials.
The flame spread and smoke emissions by the fire are the criteria of the definition of fire behaviour.
The developments have come up with the foam named POLYISOCYANURATE (PIR).
POLYISOCYANURATE (PIR) in effect ,is based on PUR chemical materials.The essential part is
the increase of the content of MDI by 2.5 and over fold with the influence of salt based catalysts where the final foam molecule is enlarged.Since the bigger molecule the higher temperatrure required to ignite the foam apllies in this case,furthermore the charring of the combusted face of the foam acts as a barrier to the oxygen to enhance the combustion and in the same time acts as an insulation layer preventing the temperature needed to consume the foam.Eventually smoke emission is lowered ceasing completely in a matter of time.
The thermal insulation properties of PIR is equal to PUR foam ranging between 150and 150 ºC.
PIR foam,due to its properties as described above,has taken its well deserved place in specifications globally.
Pürtiz,in pursuit of developments,has started to produce PIR foam in sandwich panels,spray applications and blocks which are slit from 6 upto 200 mm thick.