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POLYURETHANES
Hazards & Control
Polyurethanes find use as foams, sur evaluated for health hazards. To date, tion rates, and surfactants to control cell
face coatings, fibers, adhesives, sealants we have analyzed more than 700 sam structure. Depending upon the desired
and solid elastomers. To date our ex ples from polyurethane operations in end product, formulations may also in
perience with industrial processes has more than 50 different industries (Fig clude additional materials such as flame
been primarily related to foam products. ure 1). retardants, fillers, extenders, bacterio
The number of items made of polyure stats, and dyes. When the isocyanates
thane foam alone is almost endless and THE CHEMICAL PROCESS are mixed with the resins a reaction oc
seemingly every day new applications of curs which forms the polymeric foam
this material are being found in such Polyurethane foams are generally the structure. Simultaneously, the isocyan
diversified fields as mining (ventilation result of a combination of diisocyanates, ates react with water (if present) to
brattices), furniture (cushioning), auto polyester or poiyether resins, a blowing form carbon dioxide bubbles within the
motive (cushions and crash pads), re agent, water, catalysts to control reac structure, expanding it to the desired
frigeration (insulation), construction, density. In a fluorocarbon expanded sys
and the aerospace industry. tem, water is usually not used and the
foam structure is formed by expansion
GROWTH OF URETHANE of the low boiling fluorocarbon.
FOAM USAGE “Frothed” foams are produced by the
same reactions, but in this system part
The total U. S. production of poly of the blowing agent is a material that
■so
urethane foam in 1961 was approxi is normally a gas at room temperature.
mately 100 million pounds. In 1968, By mixing the foam ingredients under
this amount was used in furniture cush 40 pressure, the low boiling fluorocarbon
ioning alone. Projections indicate that expands the mixture immediately when
this use will require 180 million pounds the pressure is released, similar to shav
by 1975. In the construction industry, 30 ing cream when expelled from an aero
60 million pounds were used in 1968 Qmifefe© raam bg-r sf plants win® ufithom sol can. This action will account for up
with an expected use of over 200 million to 70 percent of the foam’s expansion.
•20
pounds by 1975. This year, over 70 The remaining expansion is completed
million pounds of flexible polyurethane as in the first system.
foam will be used in bedding. By 1975 •JO These two basic systems provide
this use will require 130 million pounds. versatility since both can be used to
The increased usage is further exemp meet specific needs in the factory or the
lified by the rising number of individual field. The major difference is that the
applications and work places which the mixer is operated under pressure (60-
Division of* Occupational Health has 100 psi) in frothing, while the mixer is
