ISO 1924-2:2008

Overview

ISO 1924-2:2008 - Paper and board: Determination of tensile properties - Part 2 specifies a laboratory method to measure tensile properties of paper and board using a testing machine that applies a constant rate of elongation (20 mm/min). The standard defines how to determine tensile strength (always required), and - subject to agreement - strain at break, tensile energy absorption, tensile index, tensile energy absorption index and modulus of elasticity. It is applicable to most papers and boards (including corrugated board components) but not to corrugated board itself or to tissue products covered by ISO 12625-4.

Key topics and technical requirements

• Test principle: Strain a prepared test piece to break at a constant elongation rate of 20 mm/min while recording force and, if required, elongation.
• Measured and calculated properties:
  • Tensile strength (maximum force per unit width)
  • Strain at break (elongation relative to initial span)
  • Tensile energy absorption (energy per unit surface area)
  • Tensile index and tensile energy absorption index (normalized by grammage)
  • Modulus of elasticity (slope of force–elongation curve)
• Apparatus and accuracy:
  • Tensile testing machine calibrated for force accuracy ±1% and elongation accuracy ±0.1% (extensometer recommended; see ISO 9513).
  • Clamps must grip without slippage, aligned within 1° and adjustable to the test span (normally 180 ±1 mm).
  • Means to record force–elongation and to integrate work done (for tensile energy absorption).
• Sampling and conditioning: Follow ISO 186 for sampling and ISO 187 for conditioning; handle specimens to avoid moisture changes that affect mechanical results.
• Rate dependence: Results vary with elongation rate - ISO 1924-2 (20 mm/min) produces different values than ISO 1924-3 (100 mm/min); increases of ~5–15% are common when rate is higher.

Applications and users

ISO 1924-2:2008 is intended for:

• Paper and board manufacturers for product specification and QC
• Independent testing laboratories and certification bodies
• Converters, printers and packaging engineers evaluating tensile performance
• R&D teams developing grades and coatings Practical applications include quality control of raw and finished rolls, comparative material assessment, supplier acceptance testing, and input to packaging design where tensile strength and energy absorption inform performance.

Related standards

• ISO 1924-3 (constant rate 100 mm/min)
• ISO 186 (sampling)
• ISO 187 (conditioning)
• ISO 534 / ISO 536 (thickness, grammage)
• ISO 12625-4 (tissue tensile tests)
• ISO 9513 (extensometer calibration)
• ISO 5270 (laboratory sheets testing)

Keywords: ISO 1924-2:2008, tensile properties, paper and board, constant rate of elongation, 20 mm/min, tensile strength, tensile index, modulus of elasticity, tensile testing.