| 摘要 |
<p>The method of treating open-celled polyurethane foam by the application of a modifying ingredient, such as a dye, pigment, color stabilizer or fire retardant, for example, wherein the method comprises the steps of (a) applying an excess of a liquid solution or dispersion of the modifying ingredient to a mass of the foam, (b) removing most of the excess of the liquid by squeezing the mass, (c) passing a gas, the temperature of which is between 350 DEG F. and 500 DEG F., through the material for a period of time sufficient (1) to raise the temperature of the polyurethane mass to a point at which the polyurethane will absorb the modifying ingredient, and (2) to vaporize the liquid present in the solution or dispersion, the period of time being insufficient to cause charring of the polyurethane, thereby accelerating the absorption of the modifying ingredient into the polyurethane, so as to permanently incorporate the modifying ingredient into the foam, and (d) allowing the mass to cool. The gas is chosen so as to be inert with respect to the foam, the modifying ingredient, and the liquid.</p> |
