profile strip 31 is formed a longitudinally axially parallel doctor or profile surface 310 facing the application surface 4 and which has a working gap r tapering in a wedge shaped manner in the direction of the doctor pressing line 36 and therefore forming an application material area 51 according to the embodiments of fig2 to 6 and 11 to 15 the profile strip 31 is designed in combination with a roll doctor 302 the roll doctor 302 is guided in free running manner in a longitudinally axially parallel slot like receptacle which is open towards the material web 4 and allows doctor 302 to roll on the screen 7 or relative to the material web 4 the walls of receptacle 314 are constructed as sliding surfaces 315 or provided with a suitable sliding coating according to fig2 to 6 and 12 to 15 the profile strip 31 is located in the vertical area of the doctor roll 302 along a longitudinally axially extending parallel line 316 so to engage or be pressed against doctor 302 in the vicinity of the doctor roll vertical area the profile strip 31 tilts or pivots about an axis 316 in said area it is important that the profile strip 31 resting on the doctor roll 302 has a sealing function and acts as a sealing strip with which the substance in the space 51 is sealed with respect to the area located behind the roll doctor in movement direction l the roll doctor 302 can also engage on.