Process and apparatus for fault detection in a liquid sheet and curtain coating process

摘要

The present invention relates to a process and an apparatus for detecting a fault in a flowing liquid sheet and in particular in a coating curtain. The process comprises the following steps: transmitting an electromagnetic beam to the sheet so as to irradiate approximately the entire width of the sheet in a direction approximately transverse to the sheet; recovering a beam reflected by the sheet by way of a collector; defining a reference position of the reflected beam on the collector; and noting the deviations of the reflected beam in relation to the previously defined reference position.