Paperboard Moisture Conditioning Standards and ISO 186 Batch Acceptance Sampling Protocols
Paperboard moisture verification demands ISO 186 random lot sampling and preconditioning under ISO 187 before ISO 287 gravimetric testing.
Sample Unit Selection
Sampling Protocol
Statistical sampling procedures specified in international paper testing standards govern the withdrawal of discrete rolls or packages from a production lot. Sample unit selection defines the systematic method used to pick individual reams or reels that represent the physical characteristics of an entire manufacturing run. Proper selection prevents skewed test results caused by localized mill defects or edge moisture variations across the paper reel.
The protocol specifies taking units at random intervals from at least five percent of the total packages comprising the shipment lot. Application of the protocol remains limited to lot acceptance testing, stopping once physical sample preparation for specific instruments begins.
Statistical Representativeness
Cross-machine variance and machine-direction moisture profiles require structured sampling patterns to ensure valid quality audits. Sample unit selection requires taking full-width paper strips to capture moisture and grammage fluctuations across the entire web. Selecting units exclusively from outer reel wraps introduces environmental contamination bias into burst and tensile strength evaluations.
Random sampling across multiple pallet stacks provides defensible compliance data during commercial quality disputes.
Lot Verification
Non-random sampling leads to incorrect rejection of acceptable paper shipments during mill audits. Sample unit selection provides the statistical foundation for binding quality guarantees between paper mills and converting operations.