ABSTRACT
Metal-faced sandwich panels have been extensively used as exterior walls in the building industry. Experience and testing have demonstrated that HCFC-141b blown polyisocyanurate (PIR) foams provide acceptable fire performance when incorporated into these types of panel systems.
Nowadays, the requirement for the development of all water-blown PIR foam system is getting higher, because HCFC-141b is to be phased out and water-blown system is environmental-friendly, safe and economical.
However, in general, all water-blown PIR foam system has some problems such as poor flowability, foam friability and poor adhesion strength to metal and paper. Moreover, the poor storage stability of polyol premix of PIR system due to hydrolysis is a serious issue, since polyester polyol modified PIR foams are generally used to enhance incombustion properties.
As for storage stability, the effect of various polyester components and catalysts for PIR foam preparation were examined as the factors of the increase of acid value and the change of reaction profile. Through these tests, it was found that the specific combination of polyester components and selected catalysts led to good storage stability of polyol premix. Furthermore, to improve foam properties, new polyisocyanate was developed and finally we developed new all water-blown PIR foam system which showed similar storage stability to current HCFC-141b system, high flowability, less-void appearance, good dimensional stability, good adhesion strength and excellent incombustibility.
In this paper, the relationship between each component of PIR foam and various properties will be discussed.
