Tension and tension relaxation of wet webs

The increase of paper machine production speed is often limited by the mechanical properties of wet web, i.e. wet web tensile and relaxation characteristics. As a consequence of this, many paper machines are forced to run below their design speed. So far, despite the high technological importance of wet paper rheology under dynamic conditions, very few attempts have been made to systematically study the effects of different factors affecting wet web tension and tension relaxation behaviour during short time scales. In this laboratory-scale study, the effects of several variables, such as strain rate, dryness, fibre orientation, furnishes type, fibre shape and strength additives on tension and tension relaxation of paper network were examined.