Abstract: The aim of the invention is to make it possible to vary independently of each other, i.e. better and more freely, the basic parameters in the design of a squeegee used as a flexible-plate doctor blade in a coating-material spreading device. These parameters may include the length of the chamfered surface in contact with the surface to be coated, the resistance to bending strain parallel to the spreading edge of the blade and the resistance to bending strain at right angles to the spreading edge of the blade. This aim is achieved by virtue of the fact that the flexible-blade doctor blade (squeegee) proposed does not have a constant thickness but is made up of two or more different cross-sections with steps parallel to the dosing edge, thus giving the flat sides of the doctor blade a substantially terrace-like structure. The blade may also have grooves parallel to the dosing edge.

Abstract: A process for operating a coating device provides for capturing variations of the angle of the coating edge of a doctor element, for instance in relation to the horizontal, directly by a signal generator attached to the doctor element in the vicinity of its coating edge. This signal generator may work on electromagnetic basis so that the signal will be transmitted to a receiver without any line. Preferably a tilt switch is provided which determines slight variations of a set angle of the coating edge relative to, for example, the horizontal by means of displacement of a mercury pearl and two electrodes which will be short-circuited by the mercury pearl. Other embodiments can include a laser or LED as a signal source and a CCD camera as a receiver, or an ultrasound source can be used as a signal generator.

Abstract: The disclosure concerns both an apparatus and a method for adjusting the applied weight of a coating composition on a web traveling over a support roll. The support roll is opposed by a scraper that removes excess coating composition which was just previously applied to the web. The scraper has an entrance flank that is opposed to the support roll. The downstream end of the entrance flank is defined by a sharp edged end. The length of the pressing zone between the scraper and the support roll is adjusted by swiveling the scraper around its axis with respect to the support roll so as to adjust the position of the sharp edged end of the scraper with respect to the coated surface of the web. The surface of the support roll is elastic so that it can be depressed under the pressure applied thereto by the sharp edged end of the entrance flank. The scraper may be developed as a sector of a roll having the axis of the scraper as the axis of the curve.