ISO 536 Grammage

Substrate Density

Caliper thickness interacts directly with mass per unit area to determine the specific bulk and stiffness characteristics of a fibrous web. Production mills manipulate refining intensity and wet end chemistry to achieve target weight specifications without sacrificing folding endurance or bursting strength. Paperboard destined for luxury packaging applications requires strict adherence to baseline mass targets to ensure structural rigidity under vertical stacking loads.

Converting plants measure outgoing shipments against contractual mass limits to verify fibre economy and prevent supplier disputes regarding delivered raw material volume. Deviation from specified mass thresholds alters folding carton crease behavior, leading to cracking along score lines during high speed automatic packaging runs.

Process Verification

Laboratory technicians extract representative samples across the full width of the moving paper web to confirm mass uniformity before final reel acceptance. Statistical process control charts track rolling averages and standard deviations, flagging systematic basis weight drift caused by headbox inconsistencies or stock approach fluctuations. Automated scanning sensors mounted on paper machine frames measure absorption profiles continuously, feeding correction data back to the wet end dilution system for immediate compensation.

Regulatory compliance regarding postal tariffs and packaging waste directives depends upon accurate mass verification protocols certified by independent testing laboratories. Finished corrugated containers derive their edge crush resistance ratings from the combined mass specifications of individual linerboards and fluting mediums, connecting raw material measurements directly to structural package performance.