ISO 14127:2024

Overview

ISO 14127:2024 - Carbon‑fibre‑reinforced composites - Determination of the resin, fibre and void contents - defines standardized laboratory methods to quantify resin content, fibre content and void content in carbon‑fibre‑reinforced composites. The second edition (2024) replaces and updates the 2008 edition, adding a new microscopic method (Method C) and refining resin removal procedures. The standard supports reliable material characterization and processing quality control for composite parts.

Key topics and technical requirements

• Three measurement routes:
  • Method A (resin removal) - determines fibre mass using resin removal by one of three procedures: combustion, nitric acid digestion, or sulfuric acid / hydrogen peroxide digestion. Choice depends on the resin type, combustibility and decomposition behaviour. Note: Method A has limited applicability with filled resins that resist complete dissolution/combustion.
  • Method B (thickness measurement) - calculates fibre content from composite thickness and known prepreg fibre mass per unit area. Applicable only for parts moulded from prepregs with established areal fibre mass.
  • Method C (microscopic method) - determines fibre volume content and areal void content by image analysis of polished cross‑sections. Applicable to unidirectional, orthogonal and multidirectional laminates; can be a reference for aramid or glass fibre composites but is not for fabric‑reinforced composites.
• Specimen requirements: Randomly distributed locations, minimum distance from edges, edges smoothed; at least three specimens per assessment unless otherwise agreed.
• Conditioning and measurement: Conditioning per ISO standard atmospheres (ISO 291); density determinations reference ISO 1183 parts; fibre density reference ISO 10119.
• Results and reporting: Methods include expression of results, precision statements and required test report contents.

Practical applications

ISO 14127:2024 is used for:

• Quality control during manufacturing of carbon‑fibre composites (aerospace, automotive, marine, sports).
• Material verification for acceptance testing, supplier qualification and batch comparison.
• Failure analysis and process optimization by correlating fibre/void/resin contents with mechanical performance.
• Research and development where accurate fibre volume/void measurements are needed for property prediction and modelling.

Who should use this standard

• Composites manufacturers and process engineers
• Materials testing laboratories and certification bodies
• Quality assurance and R&D teams in aerospace, automotive, wind energy and marine industries
• Standards developers and procurement specialists specifying composite acceptance criteria

Related standards

• ISO 291 - Standard atmospheres for conditioning and testing
• ISO 1183‑1 / ‑2 / ‑3 - Density determination methods for plastics
• ISO 10119 - Carbon fibre density determination
• ISO 9344, ISO 10934 - Microscopy related references

Using ISO 14127:2024 helps ensure consistent, traceable measurement of resin, fibre and void contents for carbon‑fibre‑reinforced composites, improving material qualification and process control.