| 摘要 |
A process for producing polyurethane mouldings by reaction injection moulding, comprises supplying at least one isocyanate component and one polyol component to a mixing chamber (3) where they form a polyurethane reaction mixture. The reaction mixture is then fed to a mould (1) cavity (6) via an outlet channel (4). A process for producing polyurethane mouldings by reaction injection moulding, comprises supplying at least one isocyanate component and one polyol component to a mixing chamber (3) where they form a polyurethane reaction mixture. The reaction mixture is then fed to a mould (1) cavity (6) via an outlet channel (4). The reaction mixture is exposed to a gaseous pressurising medium in the cavity and the pressure is such that gas dispersed in the mixture dissolves. The pressure is at least 1.1-10 times the solution partial pressure in the reaction mixture. Carbon dioxide is used to flush out the cavity, mixing chamber and the outlet channel. The arrangement used to produce the mouldings consists of a mixing head (2), mixing chamber, outlet channel, proximity switch, upper and lower mould sections and a gas station.
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