Auditing Virgin and Recycled Fiber Ratios in Paperboard Packaging
Auditing fiber ratios combines ISO 9184 furnish microscopy and ash testing with strict FSC and PEFC invoice-level mass balance chain of custody reconciliation.
Delamination Testing
Structural Assessment
Technical procedure used to measure the internal bond strength and ply separation resistance of multi-layered paperboard. Delamination testing identifies the force required to pull the individual layers of a substrate apart, which reveals the quality of the bonding between the pulp mats. This measurement is necessary for predicting how a material will behave during high speed printing and complex converting operations.
Testing Mechanism
One common method involves the Scott Bond test, which uses a swinging pendulum to apply a sudden shearing force to the sample. The energy absorbed during the separation of the fibres indicates the internal strength of the board. Another approach is the z-directional tensile test, which applies a slow, steady pull perpendicular to the surface of the sheet.
Both methods provide data that mill technicians use to adjust the chemical additives and refining levels in the wet end of the paper machine.
Production Significance
Insufficient internal bond strength can lead to failure when the board is subjected to the high tack of offset inks. During the printing process, the ink can pull the surface of the board away from the core, causing blisters or complete sheet separation. Delamination testing also helps converters determine if a board will withstand the stresses of creasing and folding without the layers splitting excessively.
Monitoring these values prevents press downtime and ensures that the finished packaging can survive the physical demands of shipping and handling.