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.
Open preview (PDF)Rubber, vulcanized or thermoplastic — Determination of adhesion to a rigid substrate — Part 2: Adhesion of a soft thermoplastic elastomer layer