Apparatus for applying treating media onto webs

Claim 1

Apparatus for the self-regulating application of an aqueous treating medium having a wide range of viscosities, onto a running web, said apparatus comprising a hollow body which contains said medium therein, extends over the width of the web and has, on the side from which the application is effected, a restrictor gap which extends over the same width, and has a strip of permeable material inserted therein throughout the length, taken in the direction of application, of the gap, wherein, in association with said hollow body, there are provided spring means for spring-loaded said hollow body at all times in the direction of the medium-containing interior of said body, and means for mounting said hollow body, including the components thereof which define said gap and have said strip of permeable material inserted therein, to be movable, for a corresponding adjustment of the gap, at right angles to the length of the gap, and, under the force of the spring means compress said strip of material, so that said gap and hence the amount of the throughput are automatically adjusted by the medium pressure acting against the spring means, thereby to automatically compensate for changes in medium pressure in accordance with temperature and hence viscosity variations.