Method to measure tension in a moving web and to control properties of the web

摘要

A process for determining the tension in a moving web is provided. The process includes the step of providing a web that is moving at a determined speed. The speed has a determined basis weight. A wave is created in the moving web. The speed of the propagation of the wave is determined. Also, the tension on the moving web is determined through a mathematical relationship between the wave speed, the basis weight of the web, and the speed of the web. The instability index of the web is greater than or equal to 0.5.