Patent ID: 6193184
Filing Date: 2001-02-27
Classification: B65H

Abstract:
A method of providing constant tension in a paid-out stretch of web material in a flow-packing machine, whereby said web material is supplied with a variable tension from a supply source to a web tension adjusting station from which said web material is pulled out, said web material partly surrounding a rotatably driven friction roller operating as an auxiliary driving means on said web material and having an angle of deflection determined by the location of an adjustable control roller, said method comprising the steps of:rotating said friction roller with a peripheral speed directed in the pay-out direction, said peripheral speed being substantially higher than the advancing speed of said web material; andselecting an angular position of said control roller in accordance with the friction coefficient between said web material and said friction roller for producing an increase in web tension by an associated increase of web pressure against said friction roller, said increase in web tension automatically resulting in an increased dynamic friction between said friction roller and said web material to increase the auxiliary driving effect upon said web material so as to maintain substantially constant web tension and increase the force with which said web material is pulled from said supply source.