Grade Substitution Shipped under an Unchanged Product Name
Unannounced paper grade substitution alters structural fiber bonding and surface chemistry, demanding dockside physical and chemical testing before press loading.
Paper Sample Conditioning ISO 187
Atmosphere Control
Standardized climate specifications mandate precise temperature and relative humidity environments for handling and testing paper substrates. Testing laboratories follow paper sample conditioning ISO 187 to bring paperboard specimens to moisture equilibrium before executing physical property tests. The standard specifies a constant temperature of twenty-three degrees Celsius and fifty percent relative humidity.
Conditioning rooms utilize continuous air circulation and precision environmental sensors to maintain target atmospheric boundaries.
Moisture Equilibrium
Hysteresis effects in cellulose moisture sorption necessitate pre-conditioning paper samples in low humidity atmospheres before final climate exposure. Moisture content directly dictates paper mechanical properties including tensile strength and folding endurance. Pre-drying specimens at low relative humidity ensures that paper reaches equilibrium along the absorption curve, eliminating variations caused by prior storage history.
Specimen weight measurements repeated at specified time intervals confirm that moisture content has stabilized within acceptable tolerances.
Physical Standardization
Mechanical test results obtained on unconditioned paper specimens vary widely and cannot serve as valid quality control benchmarks or commercial contract references. Standardized conditioning eliminates environmental moisture history as a variable when comparing physical testing results between paper mills and converting facilities. Paper sample conditioning ISO 187 defines the required pre-conditioning protocols, equilibrium verification procedures, and ambient climate tolerances for valid physical paper testing globally.
Compliance ensures reproducible measurements of stiffness and tensile energy absorption across commercial paper packaging supply chains. Adherence to international conditioning standards protects buyers and suppliers from commercial disputes arising from climate induced property variations.