Spray head attachment for metering gear head

Abstract

A spray head attachment adapted for use with a flow metering device such as a metering gear head is effective to discharge a plurality of spiral spray patterns of hot melt adhesive, in elongated strands or fibers, onto the backing sheet of a hygienic article. The spray head attachment includes a manifold having adhesive passageways connected to outlets of the metering gear head, air passageways connected to a source of pressurized air and recirculation passageways connected to a source of hot melt adhesive. Outlets of the adhesive and air passageways, and inlets of the recirculation passageways, are formed on a discharge surface of the manifold in groups or arrays, so that nozzles mounted to the manifold are each connected to one array of adhesive, air and recirculation passageways. Each nozzle is effective to discharge an adhesive bead and then impact the bead with jets of air directed tangentially relative to its periphery to form elongated adhesive strands or fibers and to impart a twisting motion to the fibers for deposition in a compact, spiral spray pattern onto the backing sheet of the hygienic article.