ISO 813-2:2024

Overview

ISO 813-2:2024 specifies a repeatable laboratory test method for measuring the adhesion (peel strength) of a soft thermoplastic elastomer (TPE) layer bonded to a rigid substrate. The standard is targeted mainly at soft components in the Shore A hardness range and defines the test piece geometry, conditioning, test apparatus and procedure for a 90° peel test. Note: ISO 813-2:2024 defines the test piece but does not prescribe the injection‑moulding tool, so results can vary with different mould designs.

Keywords: ISO 813-2:2024, thermoplastic elastomer, TPE adhesion, peel strength, adhesion to rigid substrate

Key topics and technical requirements

• Principle: Measure force required to peel a fixed-width TPE strip from a rigid substrate at a 90° angle.
• Apparatus:
  • Tensile testing machine (class 1 per ISO 5893).
  • Test trolley and guide pulley (recommended pulley Ø 8–9 mm); trolley horizontal start friction ≤ 4 N.
• Test pieces:
  • Standard soft component wall thickness (2 ± 0.2) mm; for very low hardness TPEs, (3 ± 0.2) mm allowed.
  • Preferably produced by two‑component injection moulding (core‑back technique recommended).
  • Moulded hard component surface roughness at bond area: RA 2.20 µm–3.20 µm (ISO 21920‑1).
  • Avoid visible defects (flow marks, sink marks, air inclusions, overmoulding) that affect bonding.
  • Minimum of five test pieces per test series.
• Conditioning and test conditions:
  • Condition specimens ≥16 h at (23 ± 2) °C / (50 ± 10) % RH (ISO 23529).
  • Peel at 100 mm/min; use trolley displacement to measure peeled length.
• Results and classification:
  • Peel strength W (N/mm) = F (N) / b (mm), where F is adhesion force evaluated per ISO 6133.
  • Fracture pattern classification (A, B, C, D, mixed patterns, or E) describes residue of TPE on substrate and failure mode.

Applications and who uses it

ISO 813-2:2024 is used by:

• TPE material suppliers and compounders for product characterization and specification.
• Injection moulders and tool designers assessing overmoulding and joint integrity.
• OEMs and product engineers in automotive, consumer goods, medical devices, electronics and industrial components where TPEs are bonded to rigid parts for functional, visual or haptic reasons.
• Testing and QA laboratories performing routine adhesion/peel testing and supplier qualification.

Practical benefits: provides a standardized, comparable way to evaluate TPE-to-substrate adhesion, guide material selection, validate moulding processes and support failure analysis.

Related standards

• ISO 5893 - Tensile test equipment specification
• ISO 6133 - Analysis of multi‑peak traces for tear and adhesion
• ISO 23529 - Conditioning of test pieces
• ISO 18899 - Calibration guide for test equipment
• ISO 21920‑1 - Surface roughness measurement

For implementation details, refer to the full ISO 813-2:2024 document and related normative references.