GB/T 47405-2026Test methods for the permeability of carbon fibre reinforcements used in liquid moulding (English PDF)

1 Scope

This document describes the principle, equipment, sample, test liquid, and test procedure for determining the permeability of carbon fiber reinforced materials used in liquid molding.

Environment, testing procedures, result calculation, and test report.

This document applies to the determination of permeability of carbon fiber reinforced materials used in vacuum-assisted infusion liquid molding, including in-plane permeability and thickness permeability.

Permeability. Refer to this method for determining the permeability of other fiber-reinforced materials.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 1226-2017 General Pressure Gauges

GB/T 10247 Viscosity Measurement Method

GB/T 30019 Determination of carbon fiber density

GB/T 40724 Terminology for Carbon Fibers and Their Composites

3 Terms and Definitions

The terms and definitions defined in GB/T 40724, as well as the following terms and definitions, apply to this document.

4 Principles

Based on Darcy's law, under a specified pressure, a liquid of known viscosity is injected into a carbon fiber reinforced material sample to determine the unsaturated flow of the liquid.

The distance and time are considered, and the permeability is calculated based on the liquid viscosity, the porosity of the reinforcing material, and the vacuum level. In-plane permeability corresponds to the X and Y directions.

Let kX and kY be the reference values; the thickness permeability corresponds to the Z direction and is denoted as kZ.