Cast Systems » Foams

RIGID CAST MATERIALS
Water/CO2-blown foams

Significant time was spent in the development of water-blown foams. Many systems were developed based on esters, ethers, and ester/ether blends. The foam systems were developed using both TDI and PAPI as the isocyanate component. All developed systems had requirements that enabled the system to be processed by hand mixing techniques or through automatic mixing equipment. Both one shot and esterification materials were used in the development of these foams. Obtained densities were from 0.5 lbs/ft3 to 70 lbs/ft3. Several of the PAPI systems incorporated the isocyanurate structure without the brittle nature of isocyanurate foams.

Many of the developed systems provided very high physical properties relating to densities. Cell structure was excellent with isotropic structure being the dominate form. As a sited example, three foam parts, 20lb/ft3, 6 x 6 x 12 inches were exposed to 140F @ 95% humidity for a period of two years being weighed and measured in weekly cycles. The three test blocks showed virtually no change in dimensions and exhibited extremely low moisture absorption. Under special conditions, this system could be carbonized in conjunction with a specific alcohol to form an open cell structure with extremely high thermal resistance.

In addition, a system was developed as an application in aircraft seats. The foam was required to have a very narrow crush ratio in psi over the complete travel during testing. The crush ratio was in the vertical direction only, with no increase in outward psi over four to six inches of travel. The crush ratio of the foam duplicates similar properties to that of cork. To site an example: after crushing a 2 x 2 inch sample, the foam still measured 2 x 2 inches; only the height exhibited any changes. Several of our systems exhibit dispense rates of 500 lbs/minute with excellent results.