Adhesive applicator, to apply adhesive to strip of filter material; has row of applicator elements, each with metering device having nozzle that can be closed or opened by driven needle

摘要

The applicator has a row of applicator elements (201) across the width of the material strip. The applicator elements have metering devices, each having one nozzle (203) that can be gradually closed and opened by a driven needle (205). At least one inner wall of an outlet section of the nozzle forms a small wedge or conical angle, preferably less than 5 deg , with an adjacent circumferential section of the needle. The metering devices adjust the rate of adhesive application, to form identical blobs of adhesive of a given size along the material and at a period defined by a metering cycle time.