Investigating Color as a Non-Destructive Indicator of Strength Loss in High Tensile Nylon 6,6 Webbings

High-performance nylon 6,6 webbings used in critical applications degrade under solar exposure, necessitating reliable methods to assess their residual strength non-destructively. This study investigates the feasibility of using instrumental color change as a predictive indicator for the loss of breaking strength. Four colors of nylon 6,6 webbings were subjected to accelerated xenon-arc solar weathering for up to 15 days. The resulting color change was quantified using both the CIELab and CIEDE2000 formulas, and residual breaking strength was measured following ASTM D6775. A regression analysis was performed to correlate these properties. The results demonstrate that a strong predictive relationship exists, but its efficacy is highly color-dependent. Webbing with high initial chroma, namely tan (R² = 0.889) and navy (R² = 0.817), showed a strong correlation between color change and strength loss. In contrast, the models for low-chroma black and white webbings were weak and unreliable. Furthermore, the simpler CIELab (ΔE*_ab) formula provided slightly more accurate predictions than the more complex CIEDE2000 (ΔE*₀₀) metric. It is concluded that colorimetry can be a viable non-destructive tool for predicting mechanical degradation, but its application is limited to specific high-chroma materials, precluding a universal model based entirely on colorimetry.