System and method for measuring untensioned product length of a web during production

摘要

A system and method is provided for determining an untensioned product length of a web moving through a printing press under tension. A controller determines a tensioned repeat length of the web in a span of the printing press while the web is moving through the printing press under tension; determines an elastic strain of the web in the span of the printing press while the web is moving through the printing press under tension; and calculates an untensioned product length of the web in the span of the printing press while the web is moving through the printing press under tension as a function of the tensioned repeat length and the elastic strain.