Overview
ISO 20863:2018 is an international standard published by the International Organization for Standardization (ISO) that specifies test methods for determining the bondability of stiffeners and toepuffs used in footwear manufacturing. This standard focuses on assessing the adhesion quality of heat-activated and solvent-activated stiffeners and toepuffs when bonded to upper and lining materials of shoes. It is essential for ensuring product durability, quality control, and material performance in footwear production.
By providing precise and repeatable testing procedures, ISO 20863:2018 helps manufacturers and laboratories evaluate the adhesive properties of components critical to shoe structure and comfort.
Key Topics
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Scope and Applicability
The standard applies to stiffeners and toepuffs bonded to shoe uppers and linings, covering two types of activation: heat and solvent-based adhesives.
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Test Setup and Equipment
- Tensile testing machine with a jaw speed of 100 mm/min ± 10 mm/min and force measurement accuracy exceeding 2%
- Heated press capable of maintaining temperatures with ±5 °C precision
- Cutting tools for preparing standard test specimens (150 mm × 30 mm)
- Reference materials such as chrome-tanned full-grain leather (L1) and non-woven fabrics
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Sample Preparation
Two methods are detailed for preparing samples:
- Method 1 for thermoactivated materials involves cutting composite specimens and bonding under specified heat and pressure conditions at several temperature levels (70°C to 150°C).
- Method 2 for solvent-activated materials uses solvent application (e.g., acetone) followed by bonding under controlled heat and pressure.
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Bondability Testing Procedure
Samples are subjected to tensile peel testing where the force required to separate bonded materials is measured under dry and wet conditions. Wet testing includes immersion in distilled water for six hours followed by tensile testing to simulate real-use scenarios.
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Results Expression
Bondability is expressed in newtons per millimeter (N/mm), calculated from the average force applied during the peel test divided by specimen width. Results are reported separately for dry and wet states to assess adhesive durability.
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Test Reporting Requirements
Reports must include references to the ISO standard, sample descriptions (commercial references, color, nature), bondability values at each test condition, test date, any deviations from the standard method, and the test method used (dry or wet adhesion).
Applications
ISO 20863:2018 serves multiple practical uses within footwear design, manufacturing, and quality assurance fields:
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Quality Control
It enables manufacturers to verify that adhesives and bonding processes for stiffeners and toepuffs meet required strength and durability standards.
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Material Development
Provides manufacturers with standardized criteria to test new adhesive materials or stiffener components during product development phases.
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Supplier Verification
Assists brands and manufacturers in evaluating materials supplied by third parties to ensure consistent bondability performance.
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Product Reliability and Comfort
By ensuring strong and durable bonding of stiffeners and toepuffs, footwear companies can enhance overall shoe shape stability, longevity, and wearer comfort.
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Regulatory Compliance
Helps companies meet technical standards often required by international trade agreements, contributing to smoother market access and reduced technical barriers to trade.
Related Standards
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ISO 7500-1: Calibration and verification of uniaxial testing machines - Important for ensuring the accuracy of tensile test equipment used in ISO 20863 procedure.
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ISO 18454: Specifies standard atmospheres for conditioning and testing shoes and components - Critical for sample conditioning prior to testing bondability.
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ISO 3696: Quality specifications for laboratory water - Relevant for preparing distilled water used in wet adhesion testing.
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CEN/TR 15990: Technical sheets for footwear materials and adhesives - Provides guidance on material characteristics referenced in sample preparation.
By adhering to ISO 20863:2018, footwear manufacturers and testing laboratories can ensure the consistency and reliability of adhesive bonding in critical shoe components, boosting product quality and consumer satisfaction globally.
