Method for producing a moulded article comprising a sprayed polyurethane layer

A method for producing an article comprising at least a polyurethane layer, in which method a polyurethane reaction mixture is supplied under pressure to a spray nozzle, within the nozzle the reaction mixture is accelerated by passing it through one or more channels wherein the flow of reaction mixture achieves a minimum cross-sectional area measured perpendicular to the flow of the reaction mixture, the accelerated reaction mixture is sprayed, with a predetermined amount of kinetic energy, through a spray opening out of the spray nozzle onto a surface to produce said polyurethane layer and the reaction mixture is allowed to cure, in which method the flow of reaction mixture achieves in said one or more channels a total minimum cross-sectional area of S mm2, S being a value smaller than 1.0, and preferably smaller than 0.9, the reaction mixture is sprayed out of the nozzle at a flow rate of between 10×S and 80×S g/sec, and, per gram reaction mixture, an amount of 0.05 to 2.5 mmol of a pressurised gas is sprayed together with the reaction mixture through said spray opening out of the nozzle to increase the kinetic energy of the reaction mixture which is sprayed out of the nozzle.