Abstract: The device for detecting local thickening in webs of paper or film is based on the fact that the thickenings are first mechanically sensed and the mechanical sensing is converted by simple means into an electrical signal. The arrangement consists basically of a stationary roller over which the web to be examined is guided and a pivotal sensor roller mounted at a narrow interval from the guide roller. The sensor roller is mounted on two separate pivotal levers and rotates at the same speed as, but in the opposite direction to, the guide roller. The pivotal levers are provided with stops which determine a gap between the guide roller and the sensor roller through which the web is guided. The stops are in the form of contact switches through which the same electrical current successively flows, so that the flow of current is temporarily interrupted when one or both stops is lifted off its support when a thickening passes through the gap.

Abstract: An arrangement for the production of webs coated with several emulsions, comprising coating and drying means arranged in succession, in the latter being connected to air supply and discharge shafts. A plurality of coating means are arranged at a selectable spacing from one another along the web which is guided in loop formation, the physical parameters for coating and drying are adjustable for each layer.