Abstract: A paper corrugating machine has features for cleaning the glue from the grooves of the glue roller. The corrugating machine is of a type having upper and lower intermeshing corrugating rollers that receive a first web of paper between them. Fingers located near the lower corrugating roller retain the web in engagement with the lower corrugating roller after it has been corrugated. A glue roller applies glue to the corrugated web at this point. The glue roller has grooves to accommodate the retaining fingers. An air jet nozzle is mounted above each groove for discharging air into the grooves to remove excess glue prior to contacting the retaining fingers. The nozzles are adjustable in their positioning and have cleaning devices for cleaning them while the machine remains in operation.