Gusmer Corporation

Other

Frederick E Gusmer

Denis S Commette

Robert A Bairunas

Closed cell phenol-aldehyde foam is prepared by a method which includes a novel frothing and curing technique. An admixture containing a liquid phenol-aldehyde resole resin, a volatile blowing agent, and a surfactant is frothed to produce a stable froth containing closed cells. The cell walls are formed of the liquid resole resin and the closed cells are expanded by the blowing agent in gaseous phase. The froth is formed into an uncured shape and the liquid resole resin is cured to the solid state in the presence of an acid catalyst to produce cured closed cell foam. The internal temperature throughout the shape during curing is above the boiling point of the blowing agent but less than 212.degree. F., and is sufficiently low to prevent further expansion of the shape in an amount to rupture the closed cell walls and thereby form an open cell structure. The liquid resole resin has a sufficiently low exothermic heat of reaction and the acid catalyst is present in an amount whereby the internal temperature of the shape during curing is less than 212.degree. F. and within the aforesaid limits. The improved closed cell foam thus prepared is also provided.

Method of preparing closed cell phenol-aldehyde foam and the closed cell

Closed cell phenol-aldehyde foam is prepared by a method which includes a novel frothing and curing technique. An admixture containing a liquid phenolaldehyde resole resin, a volatile blowing agent, and a surfactant is frothed to produce a stable froth containing closed cells. The cell walls are formed of the liquid resole resin and the closed cells are expanded by the blowing agent in gaseous phase. The froth is formed into an uncured shape and the liquid resole resin is cured to the solid state in the presence of an acid catalyst to produce cured closed cell foam. The internal temperature throughout the shape during curing is above the boiling point of the blowing agent but less than 212.degree. F., and is sufficiently low to prevent further expansion of the shape in an amount to rupture the closed cell walls and thereby form an open cell structure. The liquid resole resin has a sufficiently low exothermic heat of reaction and the acid catalyst is present in an amount whereby the internal temperature of the shape during curing is less than 212.degree. F. and within the aforesaid limits. The improved closed cell foam thus prepared is also provided.

A feeder for apparatus for ejecting a mixture of liquids, e.g. urethane foam, comprises a pair of swash plate proportioning pumps one individual to each of the liquids, e.g. resin and isocyanate, each proportioning pump being fed by a gear pump from a supply of the respective liquid. Seepage along the drive shafts of the isocyanate pumps is continuously removed by bathing them in a recirculating stream of flushing agent. The swash plate and gear pumps and flushing agent pump are all driven by a single motor from a common chain drive. The liquids are heated during passage through separate hoses to a common dispensing head or gun, by immersed coil electric resistance heaters extending lengthwise freely within the hoses. A novel control system is provided for the hose heater circuit, the adequacy of the liquid supply and other operating conditions.

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Mantoloking, NJ, United States of America

Frederick E Gusmer