Overview
ISO 20866:2018 - Footwear - Test methods for insoles - Delamination resistance defines a standardized laboratory method to measure the force required to separate the internal structure of insole materials (delamination resistance), regardless of material type. The procedure covers specimen preparation, apparatus, dry and wet testing, result expression (in megapascals) and test reporting. This standard is intended for consistent, repeatable evaluation of insole bonding integrity in footwear components.
Key topics and technical requirements
- Scope: Test method for determination of delamination resistance of insoles, irrespective of material.
- Specimen size & sampling: Cut three circular test pieces of diameter 38.0 mm ± 1.0 mm (additional three for wet testing). Sampling from finished or cut insoles is to follow ISO 17709.
- Conditioning: Condition specimens in standard atmosphere per ISO 18454 for a minimum of 24 h before testing.
- Apparatus essentials:
- Tensile-testing machine (ISO 5893 compliance) with traverse speed giving cylinder separation of 25 mm/min ± 5 mm/min.
- Pairs of solid cylinders (diameter 38.92 mm ± 0.02 mm) and collars to keep assemblies coaxial.
- Press capable of 5.00 kN ± 0.25 kN.
- Circular knife, vernier calipers, chloroprene rubber adhesive, distilled water.
- Assembly & adhesive: Coat cylinder end faces and both specimen surfaces with a solvent-based chloroprene rubber adhesive, allow 20 min drying, assemble and press at specified force; recondition 24 h.
- Test runs: Pull assemblies to failure, record maximum force for three assemblies. For wet testing, soak assemblies in distilled water for (6.0 ± 0.5) h immediately before testing.
- Result expression: Mean max force divided by mean specimen area; report in megapascals (MPa).
- Rejection criteria & reporting: Discard tests where adhesive film fails to adhere to specimen or cylinder and repeat. Test report must reference ISO 20866:2018 and include sample ID, test type (dry/wet), deviations, date, atmospheric conditions, and result.
Applications and who uses it
- Footwear manufacturers and insole suppliers seeking objective quality control of bonding and layer integrity.
- R&D teams developing new insole materials, laminates or adhesives who need comparative delamination data.
- Third-party testing laboratories performing conformity testing, product validation, or failure analysis.
- Compliance and procurement teams requiring standardized test evidence for specifications, contracts or claims.
Related standards
- ISO 5893 - Requirements for tensile-testing machines used in the method.
- ISO 17709 - Sampling location and preparation for footwear tests.
- ISO 18454 - Standard atmospheres for conditioning and testing footwear components.
Using ISO 20866:2018 helps ensure reliable, repeatable measurement of insole delamination resistance - a key indicator of insole durability and adhesive performance in footwear.
