FLOW COATER FOR COATING TAPEELIKE CARRYING SUBSTRATE WITH COATING MATERIAL

摘要

An extrusion nozzle for coating a band of carrier material with a plastic mass, comprises a hollow body extending across the full width of the carrier material. Fittings are attached for feeding and recycling the plastic mass through the extruder body, the bottom from edge of which is designed to act as a doctor. The distance at which the doctor is positioned from the carrier determines the width of the outlet slot of the nozzle, which is located so that the hollow cavity of the extruder noxxle is enclosed by its side walls. Coatings of magnetic dispersions less than two millimicrons thick for recording tapes, can be produced without difficulty. The forces necessary to hold the extruder down can be reduced considerably, so that much greater variations in pressure in the flow can be tolerated.