Abstract: To detect product defects during the production of mailing products, hygiene products or folded paper products, optical imaging sensors or capacitive sensors monitor at least one characteristic parameter or feature of the products successively moving through the production machine, to detect an actual value of each characteristic parameter or feature of each product. The detected actual value is compared with a stored nominal value for the respective characteristic parameter or feature. The result of the comparison is used to initiate or control a further measure, such as ejecting a defective product from the production line, marking a defective product so that it can be visually recognized and manually removed from the production line, or initiating corrective measures to correct the cause of the defect. The characteristic parameters or features relate to the dimensions, the position, and/or the form of the product or parts of the product.

Abstract: In the manufacture of letter envelopes from a web of material, the web is first imprinted normally and only then divided into so-called cuts or letter envelope blanks cut to size with the help of a rotating punch. In this process, the printed image has to positioned in the correct location within the blank cut to size. In order to accomplish this positioning, a few sample blanks are produced and measured first in a test run of the machine. The deviation of the actual position of the printed image from the target (or nominal) position is determined and a corrective value is accordingly input in the control electronics of the machine drive by the machine operator.