Process to determine the winding hardness of paper or foil pm a roll by application of heat to a point and monitoring rate of heat spread by thermal camera

摘要

In a process to determine the winding hardness of a web of material e.g. paper or foil, the top face of the roll is locally warmed with a defined quantity of heat and the rate at which the heat spreads is measured. The rate gives an indication of the local winding hardness at the point of heat ingress. Also claimed is a commensurate assembly which applies a defined quantity of heat to several places equally spaced around the circumference, at which the rate of heat transmission is determined. The rate at which heat spreads is determined by a thermal camera.