APPARATUS FOR SPRAYING HOT MELT ADHESIVES

摘要

An apparatus for spraying molten thermoplastic adhesive in which the outside of a solid stream of adhesive ejected from a nozzle is impacted by atomizing air to form adhesive droplets and the droplets are then directed by pattern-shaping air into a predetermined area of a substrate. The flow rate and velocity of the atomizing air and pattern-shaping air is independently controlled by separate regulating valves to permit variation of the size of the adhesive droplets formed and the width of the pattern of droplets deposited on a substrate. Control valves are provided to sequence the flow of adhesive discharged from the nozzle with the flow of atomizing and pattern-shaping air such that the flow of atomizing and pattern-shaping air is initiated before the flow of adhesive from the nozzle begins and after the flow of adhesive therefrom is terminated.