Variable volume hot melt adhesive dispensing nozzle or die assembly with choke suppression

摘要

A dual, variable volume hot melt adhesive dispensing nozzle or die assembly is provided with a pair of choke slots within a first fluid control plate. The provision of the choke slots within the first fluid control plate effectively restricts and retards the flow of the fluid through such choke slots whereby volumes of the fluids are effectively built up and stored upstream of the choke slots so as to effectively delay the reaction of pressure spikes upon the fluid flows under both positive and negative conditions. This buildup in pressure and volume is then dispensed over time so as to cause the fluid flow to smoothly transition between positive and negative spiked fluid flow conditions and normal fluid flow conditions. Accordingly, the pressure spikes do not adversely affect the resulting fluid flows whereby, for example, under conventional negative pressure spike conditions, gaps in the dispensed hot melt adhesive would otherwise occur.

主权项

1. A variable volume hot melt adhesive dispensing nozzle or die assembly, comprising:
a first fluid flow of a first hot melt adhesive; a second fluid flow of a second hot melt adhesive; a plurality of hot melt adhesive dispensing nozzles, each one of said hot melt adhesive dispensing nozzle having a predetermined cross-sectional area; first and second choke slots, defined within a first fluid control plate, for causing said first and second fluid flows of hot melt adhesive to flow toward each other such that said first and second fluid flows can be combined into a single fluid flow at a fluid flow location located downstream from said first and second choke slots, and for effectively delaying the reaction of pressure spikes upon said combined fluid flow when one of said first or second fluid flows of said first and second hot melt adhesives is intermittently discontinued; and a second fluid control plate located downstream from said first fluid control plate and said first and second choke slots for combining said first and second fluid flows of said first and second hot melt adhesives into a combined flow of hot melt adhesive and for conducting said combined flow of hot melt adhesive toward said plurality of hot melt adhesive dispensing nozzles.