ISO 287:2017

Overview - ISO 287:2017 (Paper and board - Oven-drying method for moisture content)

ISO 287:2017 specifies an oven-drying method to determine the moisture content of a lot of paper and board. The standard covers sampling, selection and preparation of test pieces at the time of sampling, oven-drying to constant mass, calculation and reporting of results. It applies to all lot types (including corrugated and solid board) provided the material contains no volatile substances other than water. For dry-matter determinations of individual samples, ISO 638 is referenced.

Key topics and technical requirements

• Scope & principle: Moisture content is calculated from the mass loss of test pieces weighed at sampling and after drying to constant mass.
• Sampling: Units to be sampled are selected per ISO 186; test pieces must be enclosed immediately in water‑vapour‑proof containers to avoid atmospheric moisture changes.
• Apparatus:
  • Balance with accuracy 0.05% (or better).
  • Oven capable of maintaining (105 ± 2) °C, properly ventilated.
  • Desiccator and water‑vapour‑proof containers.
• Test piece preparation:
  • Typical test-piece mass: at least 50 g (minimum 25 g allowed for very lightweight papers-must be reported).
  • Discard outermost/damaged sheets (and additional layers as needed) before selecting sheets/strips.
  • Duplicate test pieces recommended for each unit sampled.
  • Specific procedures for reels, reams, parcels, and for determining centre vs edge variations are specified in Clause 8.
• Drying to constant mass:
  • Constant mass is defined after drying at (105 ± 2) °C until the mass change between two successive dryings (separated by at least half the initial drying period) does not exceed 0.1% of the initial mass.
• Reporting: Test report must include the sampling and test-piece selection procedure, masses, calculated moisture content (average and, if required, variation), and relevant test conditions. Precision data are provided in Annex A.

Practical applications and users

• Quality control in papermaking and board production.
• Incoming inspection by buyers and paper merchants.
• Process control for converters, printers and copiers where moisture affects runnability, curl and dimensional stability.
• Laboratory testing to verify compliance with contract specifications and to troubleshoot moisture-related defects.

Related standards

• ISO 186 - Sampling to determine average quality (referenced for unit selection).
• ISO 638 - Determination of dry matter content of paper and board (for sample dry-mass calculations).

Keywords: ISO 287:2017, moisture content, oven-drying method, paper and board, sampling, test pieces, drying to constant mass, paper quality control.