Production of fibrous sheet, e.g. for filter applications, involves spraying hot melt adhesive containing a functional filler onto a fibrous base layer and then adding an outer layer which has been sprayed with unfilled adhesive

摘要

A method for making fibrous sheet material with (A) base layer(s), (B) outer layer(s) and (C) functional interlayer(s) comprising filler-loaded hot melt adhesive, by spraying adhesive towards the moving base layer (A), charging the spray with filler in a zone between the nozzle and (A), depositing the loaded spray on (A) to form layer (C) and then laying down layer (B), in which layer (B) is guided and/or the adhesive spray is directed in such a way that (B) is sprayed with unfilled adhesive before it is laid onto (C).