ISO 10352:2020

Overview

ISO 10352:2020 - Fibre-reinforced plastics - Moulding compounds and prepregs - Determination of mass per unit area and fibre mass per unit area - defines standard test methods for measuring mass per unit area and fibre mass per unit area of moulding compounds and prepregs. The standard applies to unidirectional sheets, tapes, fabrics and mats using common reinforcements (aramid, carbon, glass, etc.) and matrices (thermosetting or thermoplastic). It excludes prepregs whose reinforcement is soluble in the solvents used to remove the resin.

Key search terms: ISO 10352:2020, fibre-reinforced plastics, prepregs, moulding compound, mass per unit area, fibre mass per unit area.

Key topics and technical requirements

• Scope and applicability

  • Applicable to moulding compounds and preimpregnated materials (sheet, tape, fabric, mats).
  • Reinforcement sizing/finishes that dissolve with resin are treated as resin content.
  • Not applicable where reinforcement dissolves in the chosen solvents.

• Primary measurements

  • Mass per unit area: weight of a specimen with known area; specimens are conditioned if manufactured using solvents or if volatile content is significant.
  • Fibre mass per unit area: five accepted methods (A–E) to determine fibre content.

• Five methods for fibre mass per unit area

  • Method A - Soxhlet extraction: solvent extraction in Soxhlet apparatus; weigh to constant mass after extraction.
  • Method B - Solvent immersion: extraction by immersion in a beaker; faster alternative to A (A preferred in disputes).
  • Method C - Loss on ignition: decomposition of resin by controlled ignition and weighing to constant mass.
  • Method D - Wet combustion: acid digestion using concentrated sulphuric acid and hydrogen peroxide, followed by weighing.
  • Method E - Calculation: based on known linear density (ISO 1889) and yarn count per unit length (ISO 4602).

• Apparatus & reagents: precision balance (0.1 mg graduations), square templates, ovens (105 °C), Soxhlet equipment, and appropriate analytical-grade solvents (e.g., MEK, THF, acetone, NMP).

• Conditioning and reporting: conditioning per ISO 291; results expressed as mass per unit area and reported with method, specimen details and precision.

Applications - who uses this standard

• Composite material manufacturers and quality control laboratories
• Test laboratories and certification bodies validating prepreg and moulding compound specifications
• R&D teams developing composite formulations or layups
• Procurement and compliance teams specifying material acceptance criteria

Practical benefits: repeatable measurement of areal weight and fibre content for process control, material specification, and acceptance testing.

Related standards

• ISO 291 - Standard atmospheres for conditioning and testing
• ISO 472 - Plastics - Vocabulary
• ISO 1889 - Reinforcement yarns - Determination of linear density
• ISO 4602 - Reinforcements - Woven fabrics - Number of yarns per unit length

ISO 10352:2020 provides a harmonized framework for accurate, comparable measurement of areal mass and fibre content in fibre-reinforced plastics, supporting quality assurance and material specification across composite supply chains.