Patent ID: 6027769
Filing Date: 2000-02-22
Classification: B05D,C08G,C09D

Abstract:
A method for depositing a polyurethane first component and at least one second component having a dissimilar composition from said polyurethane first component on a cylindrical surface comprising the steps of:(a) rotating the cylindrical surface about its axis;(b) locating a mixing head a predetermined distance from the cylindrical surface, said mixing head being connected to separate supply means for each of said components via flow controlling means;(c) opening a first flow controlling means thereby supplying the polyurethane first component to the mixing head;(d) repeatedly moving the mixing head in the axial direction along the rotating cylindrical surface while depositing the polyurethane first component from the mixing head onto the cylindrical surface;(e) opening a second flow controlling means to the extent necessary to supply a second component having a dissimilar composition from said polyurethane first component to the mixing head at a flow rate lower than that at which the polyurethane first component is supplied;(f) decreasing the flow rate of the polyurethane first component while increasing the flow rate of the second component until the flow of the polyurethane first component is terminated and a predetermined quantity of the second component has been deposited on the cylindrical surface;whereby the cylindrical surface is coated with layers of the polyurethane first component and the second component and, between them, a gradient of the two components running from the cylindrical surface to the outer surface of the coatings and no interface.