ISO 813:2019

Overview

ISO 813:2019 specifies a laboratory method for measuring the adhesive strength of vulcanized or thermoplastic rubber bonded to a rigid substrate using the 90° peel method. The test uses a strip of rubber bonded to a single rigid plate and measures the force required to peel the rubber at a right angle (90°). The standard is intended for material selection, adhesive system development and production process control. It is not suitable for high‑hardness rubbers (typically above 85 IRHD).

Key topics and technical requirements

• Test principle: measure maximum force to separate rubber from substrate at a 90° peel angle and express adhesion strength in N/mm (maximum force ÷ specimen width).
• Specimen dimensions:
  • Rubber thickness in test area: 6.0 mm ± 0.1 mm
  • Specimen width: 25.0 mm ± 0.1 mm
  • Specimen length: 125 mm
  • Bonded area: 25 mm × 25 mm ± 0.1 mm
  • Recommended substrate thickness: ≥ 1.5 mm
• Apparatus:
  • Tensile-testing machine meeting ISO 5893, rate of traverse 50 mm/min ± 5 mm/min, force accuracy corresponding to class 1.
  • Fixtures and grips to ensure a perpendicular 90° peel and prevent rubber slippage or rupture.
  • Optional temperature-controlled chamber for non‑standard temperatures.
• Preparation and conditioning:
  • Clean and prepare bonding surfaces per the adhesive system requirements.
  • At least four test pieces per test.
  • Condition specimens as per ISO 23529; minimum 16 hours after moulding and conditioning immediately before test at standard laboratory temperatures (23 °C ± 2 °C or 27 °C ± 2 °C).
• Results & reporting:
  • Report adhesion strength (N/mm) and type of failure using symbols: R (rubber), RC (rubber/adhesive interface), CP (adhesive/primer), PS (primer/substrate).
  • Annexes cover viscoelastic behaviour analysis and calibration schedule.

Applications and who uses it

ISO 813:2019 is used by:

• R&D and formulation teams for rubber compound and adhesive system development.
• Quality control laboratories to monitor bonding performance during manufacturing.
• Test laboratories verifying the peel performance of bonded rubber assemblies.
• Engineers selecting materials and adhesives for products where rubber is bonded to rigid substrates (e.g., seals, bonded components, gaskets). The standard provides repeatable, comparable peel test data useful for product design decisions and process control.

Related standards

• ISO 5893 - Tensile test machine requirements (constant rate of traverse)
• ISO 23529 - Preparing and conditioning rubber test pieces
• ISO 18899 - Guide to calibration of test equipment

Keywords: ISO 813:2019, 90° peel method, rubber adhesion testing, peel test, adhesion strength, vulcanized rubber, thermoplastic rubber, adhesion failure.