SIST EN ISO 20535:2022 PDF

EN ISO 20535:2022 - Overview

EN ISO 20535:2022 (identical to ISO 20535:2019) is a CEN-adopted test method for measuring dimensional change of footwear insoles and insocks after a controlled cycle of wetting and drying. The standard applies regardless of material and defines sampling, apparatus, conditioning, measurement and reporting procedures to quantify thickness, length and width change and to record visual effects following immersion in distilled water or artificial perspiration.

Keywords: EN ISO 20535:2022, ISO 20535:2019, footwear test, insoles, insocks, dimensional change, wetting and drying, artificial perspiration.

Key topics and technical requirements

• Scope and purpose: Determine dimensional changes (thickness, length, width) of insoles/insocks after immersion and drying.
• Sampling & conditioning: Cut two square test pieces (50 ± 2 mm) from each material; condition per ISO 18454 for a minimum of 24 h.
• Apparatus: Dial micrometer (0.01 mm accuracy with 10 mm presser foot, 50 ± 5 kPa), stainless steel ruler (0.1 mm), oven (40 ± 2 °C), immersion container, cutting device, pH-meter and weights to maintain immersion.
• Reagents: Distilled water or acid/alkaline artificial perspiration prepared per ISO 105‑E04.
• Measurement method: Mark reference points on the square test piece (AB, CD, AC, BD; thickness at E, F, G, H, I). Record initial dimensions, immerse fully for 6 h, wipe, dry in oven 24 h, then re-measure.
• Calculations and reporting: Express thickness change and length/width change as percentages (formulas provided), average results for two pieces, and report visual changes (delamination, unevenness, colour shift). Test report must reference ISO 20535 and include sample description, liquid used, numerical results, deviations and date.

Practical applications and users

• Who uses it: Footwear manufacturers, component and insole suppliers, independent testing laboratories, R&D teams, quality control and compliance officers.
• Why use it:
  • Evaluate dimensional stability of insoles/insocks after exposure to moisture or perspiration.
  • Support material selection and product development for comfort and fit retention.
  • Verify supplier claims and ensure consistent production quality.
  • Provide documented test evidence for product specifications, technical files or regulatory/market requirements.

Related standards

• ISO 105‑E04:2013 - Colour fastness to perspiration (artificial perspiration solutions)
• ISO 17709 - Sampling location, preparation and conditioning reference system
• ISO 18454 - Standard atmospheres for conditioning/testing
• ISO 19952 - Footwear vocabulary

EN ISO 20535:2022 provides a repeatable, standardized procedure for assessing how insoles and insocks respond dimensionally to wetting/drying-critical for durability, comfort and fit in footwear product development and quality assurance.