Method and apparatus for applying narrow, closely spaced beads of viscous liquid to a substrate

Claim 1

Apparatus for applying multiple, narrow, closely spaced, parallel beads of viscous fluid upon a moving substrate, which apparatus comprises support means for said substrate, a first blade having a bottom side and a narrow longitudinal slot cavity on one other side thereof, said blade having inlet port means opening into said slot cavity, said slot cavity extending laterally of the direction of movement of the substrate, a second blade having a bottom side and a substantially flat surface on one other side thereof, a shim sandwiched between said other side of said first blade and said other side of said second blade, said shim having a plurality of parallel, spaced slots open to one edge of said shim and in fluid communication with said slot cavity of said first blade, said one edge of said shim being exposed to the substrate but spaced therefrom, said parallel, spaced slots of said shim being spaced apart laterally of the direction of movement of said web, said spaced slots of said shim being no more than approximately 0.10 inches in width and said shim being no more than approximately 0.10 inches in thickness such that beads of said viscous material emitted from exit openings are narrow and vary closely spaced, and said bottom sides of said first and second blades and said one edge of said shim being spaced a substantial distance above said support means for said substrate such that the beads of viscous fluid emitted from said spaced slots are not sheared by one of said blades as they are emitted from said exit openings.