Atmospheric Conditioning
This procedure dictates the thermal and humidity settings required for testing paper substrates. The iso 187 standard defines the specific temperature and relative humidity values necessary to stabilize test samples before mechanical evaluation. It governs the equilibrium state of fibres by forcing moisture content into a predictable range to eliminate variability from environmental exposure.
Laboratories apply these requirements to ensure repeatability in tensile strength, tear resistance and folding endurance assessments across different geographic sites. Stability occurs when the mass of the substrate remains constant under the stated conditions. The protocol restricts testing to samples that reach this equilibrium, preventing artificial inflation of data caused by ambient humidity changes.
Climatic Preparation
Technicians place materials in a controlled room to ensure the iso 187 constraints remain constant during the entire duration of the measurement process. Air circulation removes stagnant pockets of moisture, creating a uniform environment around every surface of the sheet. Proper conditioning requires the exposure of all sides to the circulating air, as stacked sheets impede the necessary moisture exchange between the fibre matrix and the room air.
The protocol specifies a temperature of twenty three degrees Celsius and a relative humidity of fifty percent for standard testing. Deviations from these targets force shifts in the physical response of the paper, leading to incorrect performance ratings. A fibre claim depends upon the accuracy of this conditioning step, because moisture alters the stiffness and flexibility of the cellulose network.
Calibration of sensors must align with the parameters prescribed in the document to maintain technical validity.
Measurement Integrity
Results generated without adherence to iso 187 fail to provide reliable benchmarks for converting operations or printing accuracy. Equipment on a high speed filling line demands substrates with consistent structural dimensions, which only standardized moisture levels guarantee. Excessive humidity softens the lignin bonds, while dryness creates brittleness that causes web breaks during high tension processing.
Mills establish these benchmarks to align their internal quality control with the requirements of converters and end users. Precise conditioning acts as the bridge between raw material potential and the operational limits of machinery. Any deviation from the established climate control renders a laboratory report invalid for commercial disputes or quality certification.
Conformity with this protocol provides the baseline for all physical property verification.
