ISO 9895:2008 PDF

Overview

ISO 9895:2008 - Paper and board - Compressive strength - Short-span test specifies a standardized laboratory method for measuring the edgewise (short-span) compressive strength of paper and board used in container and box manufacture. The method uses a short-span compressive tester to determine compressive strength in both the machine direction (MD) and cross direction (CD). ISO 9895:2008 is recommended for papers and boards with a grammage of 100–400 g/m².

Key Topics and Requirements

• Test principle: A 15 mm wide strip is clamped across a 0.70 mm ± 0.05 mm free span and the clamps are driven together until compressive failure. The maximum force is recorded.
• Apparatus:
  • Short-span compressive tester with two clamps 30 mm long and high-friction surfaces.
  • Constant clamping force of 2300 N ± 500 N.
  • Test speed 3 mm/min ± 1 mm/min.
  • Load measurement accurate to ±1% over 10–100% of full scale; device to check clamping force and allow calibration.
• Specimens and conditioning:
  • Test pieces: strips ≥70 mm long, 15.0 mm ± 0.1 mm wide.
  • Cut and condition according to ISO 186 and ISO 187; grammage per ISO 536 if required.
  • At least 20 determinations per direction to reduce local variation effects.
• Calculations:
  • Compressive strength (σC) = mean maximum force (F) / initial width (b) - reported in kN/m to three significant figures.
  • Compressive index = (1000 × σC) / grammage (g) - reported in kN·m/kg.
• Precision:
  • Typical single-lab coefficient of variation