摘要 |
A device for intermittent application of liquids such as adhesive, in particular hot-melt adhesive, to material moved relatively to the device, comprises a reservoir for the liquid, an application nozzle which is preferably formed as slit nozzle or a plurality of adjacent application passages, a supply line from the reservoir to the nozzle, a needle valve provided shortly upstream from the nozzle, a means for interrupting the flow from the reservoir to the nozzle at desired intervals, a return line to the reservoir connected to the supply line upstream from the main valve and a second needle valve for shutting off the return line. The second needle valve is larger than the main valve and lies as preliminary valve in the supply line a small distance upstream from the main valve; both valves are controllable in adjustable time relationship with respect to each other.
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