DIN ISO 3039:2011-06

The document specifies a method for determining the grammage of the component layers from which corrugated fibreboard has been made. This document is applicable to all types of corrugated fibreboard. This document describes a procedure where the separated component layers are allowed to dry unrestrained and freely. In 2008, an international round-robin test was performed to compare precision data between the two drying procedures: - free, unrestrained drying which can involve shrinkage; - restraint drying where the layers are prevented from shrinking. As no statistical provable difference in the repeatability and the reproducibility between the two drying procedures was observed, the faster and simpler procedure, that is the free drying method, was chosen for this International Standard.