ISO 5630-1:1991

Overview

ISO 5630-1:1991 - "Paper and board - Accelerated ageing - Part 1: Dry heat treatment at 105 °C" specifies a standardized method for accelerating the ageing of paper and board by dry heat treatment at 105 °C. The method is intended to provide comparative information on mechanical, chemical and optical property changes after exposure to elevated temperature in the dark. It is not applicable to certain high-purity papers (e.g., electrical insulation papers) for which ISO 5630-4 is more suitable. The standard does not mandate which end-point tests to run - that choice is left to the contracting parties.

Key topics and technical requirements

• Treatment conditions
  • Dry heat in a ventilated oven at 105 °C ± 2 °C.
  • Oven air renewal rate ≥ 10 air changes per hour to ensure uniform exposure.
  • Samples suspended so they do not touch and are ≥ 100 mm from oven walls; avoid direct radiation from heating elements.
  • Tests performed in the dark to eliminate light-induced changes.
• Recommended durations
  • Preferred: 72 h ± 1 h. Alternatives (by agreement): 24 h, 48 h or 144 h ± 1 h.
  • It is acceptable to run multiple durations (e.g., to plot properties vs. time) if sufficient sample sets are available.
• Conditioning
  • At least 2 h before end of treatment, place untreated samples in a desiccator or preconditioning device at 10–35% RH.
  • After treatment, transfer treated and untreated samples to the same conditioning atmosphere per ISO 187 before testing.
• Reporting requirements
  • Include standard reference, sample identification, date/place, temperature and duration, atmosphere conditions (temperature/RH), number of tests, mean and standard deviation for treated and untreated results, and any deviations or influencing factors.
• Suggested property measurements
  • Mechanical: folding endurance (ISO 5626), tensile (ISO 1924), tear (ISO 1974), burst (ISO 2758/2759).
  • Chemical: pH (ISO 6588), alkali solubility (ISO 692).
  • Optical: diffuse blue reflectance (ISO 2470).

Applications and users

ISO 5630-1 is used for:

• Quality control and R&D in paper and board manufacturing
• Comparative stability testing for packaging, printing papers, and book papers
• Conservation labs, archives and libraries assessing paper permanence (as a comparative, accelerated indicator)
• Suppliers and buyers establishing contractual test methods for material stability

Note: For close correlation with natural ageing, humid ageing methods (ISO 5630-2/3) may be preferred; for high-temperature insulation papers use ISO 5630-4.

Related standards

• ISO 5630 (series): Parts 2, 3 (humid heat methods) and 4 (high-temperature heat)
• ISO 187 (conditioning and testing atmosphere)
• ISO 186 (sampling)
• Referenced property test standards: ISO 5626, ISO 1924, ISO 1974, ISO 2758/2759, ISO 6588, ISO 692, ISO 2470

Keywords: ISO 5630-1, accelerated ageing, dry heat treatment, paper and board, 105°C, paper aging test, archival paper stability, quality control.