PU (polyurethane foam)

Invented in 1937 by Otto Bayer in Germany, polyurethanes most desirable attributes is their ability to be turned into foam. Making a foam requires the formation of a gas at the same time as the urethane polymerisation (gellation) is occurring. The gas can be carbon dioxide, either generated by reacting isocyanate with water or added as a gas; it also be produced by boiling volatile liquids. In the latter case heat generated by the polymerisation causes the liquids to vaporise. Isocyanates used to make polyurethane have two or more isocyanate groups on each molecule. The most commonly used isocyanates are the aromatic diisocyanates, toluene diisocyanate (TDI) and methylene diphenyl diisocyanate, (MDi). In the surf industry, there has been a battle over the best and safest one to use. It is widely recognised that TDi, in a closed and controlled environment, is far less damaging to the environment than MDi – despite MDi being touted as the safer alternative. A noted environmentalist says MDi is up to 92 times worse for greenhouse gas pollution. The mistaken view of TDi has also led to a far more relaxed use of MDi in foam producing environments, leading to casual use that has endangered marine life and human health to a far greater degree than TDi. Some say they’ve seen MDi being washed into sewers in some factories!  In the USA, the tough chemical and Environmental Protection Agency, (EPA) demands and strictly enforces wide-ranging safety rules for the use of isocyanates. Highly sophisticated production in closed conditions at US Blanks produces the finest PU foam blanks in the world, under the strictest regime for production anywhere. Elsewhere, relaxed regulations has led to environmental disasters. In Mexico, both cheap labour and poor protection for workers and the environment might enable cheaper blanks, but at a considerable cost. 

In the olden, golden days of surfing, wood was the choose of surfboard makers before Polyurethane foam changed the industry over-night. The front runners were Gordon Clark – of course – and others. Today, the sophisticated and safe use of water-blown foam at US Blanks has produced a market leading polyurethane foam, although the increasing switch to Expanded Polystyrene Foam is changing the trends in foam production.