200 u00b0 200 u00b0 325 u00b0 350 u00b0 375 u00b0 f a series of upper platens at a gap of about 6 34 from the bottom platens for the unheated rt upper platens and a gap of 1 34 for the heated upper platens were controlled to the following temperatures rt rt rt 450 u00b0 450 u00b0 450 u00b0 f the cured product then passed through an air cooling section a series of drive rollers and was wound up on a take up roll details of the urethane formulation and the catalyst and acetyl acetone levels used are as follows table 1______________________________________formulation amaterial company description parts______________________________________polymer polyol arco 34 45 about 300 molecular 56 weight polyoxypropylene triol with polystyrene and polyacrylonitrile grafted onto the poly oxypropylene chain acrylonitrile content is 9 9 by weight styrene content is 8 1 by weight thus total mole cular weight is about 3740polyesterpolyol union carbide a 530 molecular weight 11 0200 caprolactone base poly ester dioldipropyleneglycol about 134 molecular 9 weight secondary ether diol surfactant osi specialties a high molecular weight 3 inc l5614 block copolymer of poly dimethylsiloxane and polyoxyalkylene diluted at about 50 weight per cent with a linear alkyl benzenealumina 21trihydrate fillermdi adduct dow isonate a mixture of mdi 30 143l diphenyl methane diiso cyanate and a tri functional cycloadduct produced by introducing carbodiimide linkages in mdi ______________________________________ table 2______________________________________catalyst and acetyl acetone levels versus compression.