METHOD OF MULTI-LAYER COATING

摘要

IMPROVED METHOD OF MULTI-LAYER COATING The simultaneous high speed application of a plurality of liquid coating compositions to a moving web by the method, of multi-layer bead coating is improved by coating the lowermost layer as a thin layer formed from a low viscosity coating composition and coating the layer immediately above the lowermost layer as a thicker layer of higher viscosity such that vertical action of the coating bead is confined to the lowermost layer and the layer immediately above it. By this means, intermixing of the coating composition forming the lowermost layer with the coating composition forming the layer immediately above it occurs, but all other layers are coated in discrete form. The method is especially useful in the manufacture of multi-layer photographic films and papers.