GB/T 8924-2026 Test method for flammability characteristics of fiber reinforced plastics—Oxygen index method English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS
CCS
National Standard of the People's Republic of China
GB/T 8924-2026
Test method for flammability characteristics of fiber reinforced plastics - Oxygen index method
纤维增强塑料燃烧性能试验方法 氧指数法
Issue date: 2026-01-28 Implementation date: 2027-02-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Test apparatus
6 Test specimens
7 Test procedure
8 Calculation of results
9 Test results
10 Test report
Test method for burning behaviour of fibre-reinforced plastics — Oxygen index method
1 Scope
This document specifies the principle, test apparatus, test specimens, test procedure, calculation of results, test results and test report for the oxygen index test of fibre-reinforced plastics.
This document is applicable to the determination of the oxygen index of fibre-reinforced plastics, and is not applicable to the evaluation of materials that exhibit high shrinkage after heating.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 1446, General principles of test methods for performance of fibre-reinforced plastics
GB/T 3863, Industrial oxygen
GB/T 3864, Industrial nitrogen
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
oxygen index
The minimum oxygen concentration, expressed as a volume fraction, in a mixture of nitrogen and oxygen flowing at (23 ± 2) °C that just supports combustion of a material.
4 Principle
A test specimen is vertically fixed in a combustion tube, and a mixture of oxygen and nitrogen flows upwards from the bottom. The top of the specimen is ignited, and the burning length and time are observed and compared with specified criteria. A series of specimens are tested at different oxygen concentrations to determine the minimum oxygen concentration that just supports steady combustion of the specimen, expressed as the volume fraction of oxygen in the gas mixture.
5 Test apparatus
5.1 General
A schematic diagram of the oxygen index tester is shown in Figure 1, and it shall include at least the components specified in 5.2 to 5.5.
5.2 Combustion tube
A heat-resistant glass tube with an internal diameter of 75 mm to 100 mm and a height of 450 mm to 500 mm, with a top flow-restricting cap having an outlet internal diameter of 40 mm, vertically fixed on a base through which the oxygen-nitrogen gas mixture can pass. The bottom is filled with glass beads of 3 mm to 5 mm diameter to a height of 80 mm to 100 mm. A metal mesh is placed above the glass beads to prevent falling burning debris from blocking the gas inlet and the gas distribution passage.
5.3 Specimen holder
A component capable of being fixed at the central axis position of the combustion tube and holding the specimen vertically. The contour of the specimen holder and its support shall be smooth to minimize turbulence in the introduced gas.
5.4 Gas control and measuring devices
5.4.1 Gas control device
A device for controlling the volume fraction of oxygen in the mixed gas entering the combustion tube, with a resolution of 0.1 %. At a gas flow rate of (40 ± 2) mm/s, the oxygen concentration adjustment accuracy shall not be less than ±0.2 %.
5.4.2 Gas measuring device
A device for measuring the volume fraction of oxygen in the mixed gas entering the combustion tube, with a measurement accuracy of ±0.1 %.
5.5 Gas supply system
The gas supply system consists of oxygen and nitrogen cylinders and pressure regulators. The oxygen shall comply with GB/T 3863, and the nitrogen shall comply with GB/T 3864. The gas operating pressure shall not be less than 1 MPa.
5.6 Igniter
A device made of a metal tube with a nozzle tip having an internal diameter of (2 ± 1) mm. The flame length is adjustable, and it can enter above the combustion tube to ignite the specimen. When the nozzle is directed vertically downwards, the flame length shall be (16 ± 4) mm. The fuel gas may be propane, butane, natural gas, etc.
For arbitration testing, propane without air mixing shall be used as the ignition gas.
5.7 Exhaust system
A system capable of removing smoke and ash particles generated by combustion, without affecting the gas flow velocity and temperature in the combustion tube.
5.8 Other equipment
5.8.1 Stopwatch
Accuracy ±0.5 s.
5.8.2 Vernier calliper
Accuracy 0.01 mm.
6 Test specimens
6.1 Specimen preparation
Test specimens shall be prepared in accordance with the relevant provisions of GB/T 1446.
6.2 Specimen dimensions
The specimen length shall be 70 mm to 150 mm, the width shall be (6.5 ± 0.5) mm, and the thickness shall be (3.00 ± 0.25) mm. Specimens of other thicknesses may also be tested, but the test results can only be compared for the same thickness.
6.3 Number of specimens
Not less than 15 specimens per group.
6.4 Appearance requirements
The appearance of specimens shall comply with the relevant provisions of GB/T 1446.
6.5 Conditioning and test environment
Conditioning and test environment shall be carried out in accordance with the relevant provisions of GB/T 1446.
Standard
GB/T 8924-2026 Test method for flammability characteristics of fiber reinforced plastics—Oxygen index method (English)
Standard No.
GB/T 8924-2026
Status
to be valid
Language
English
File Format
PDF
Word Count
6500 words
Translation Price(USD)
195.0
Implemented on
2026-12-1
Delivery
via email in 1~3 business day
Detail of GB/T 8924-2026
Standard No.
GB/T 8924-2026
English Name
Test method for flammability characteristics of fiber reinforced plastics—Oxygen index method
GB/T 8924-2026 Test method for flammability characteristics of fiber reinforced plastics—Oxygen index method English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS
CCS
National Standard of the People's Republic of China
GB/T 8924-2026
Test method for flammability characteristics of fiber reinforced plastics - Oxygen index method
纤维增强塑料燃烧性能试验方法 氧指数法
Issue date: 2026-01-28 Implementation date: 2027-02-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Test apparatus
6 Test specimens
7 Test procedure
8 Calculation of results
9 Test results
10 Test report
Test method for burning behaviour of fibre-reinforced plastics — Oxygen index method
1 Scope
This document specifies the principle, test apparatus, test specimens, test procedure, calculation of results, test results and test report for the oxygen index test of fibre-reinforced plastics.
This document is applicable to the determination of the oxygen index of fibre-reinforced plastics, and is not applicable to the evaluation of materials that exhibit high shrinkage after heating.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 1446, General principles of test methods for performance of fibre-reinforced plastics
GB/T 3863, Industrial oxygen
GB/T 3864, Industrial nitrogen
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
oxygen index
The minimum oxygen concentration, expressed as a volume fraction, in a mixture of nitrogen and oxygen flowing at (23 ± 2) °C that just supports combustion of a material.
4 Principle
A test specimen is vertically fixed in a combustion tube, and a mixture of oxygen and nitrogen flows upwards from the bottom. The top of the specimen is ignited, and the burning length and time are observed and compared with specified criteria. A series of specimens are tested at different oxygen concentrations to determine the minimum oxygen concentration that just supports steady combustion of the specimen, expressed as the volume fraction of oxygen in the gas mixture.
5 Test apparatus
5.1 General
A schematic diagram of the oxygen index tester is shown in Figure 1, and it shall include at least the components specified in 5.2 to 5.5.
5.2 Combustion tube
A heat-resistant glass tube with an internal diameter of 75 mm to 100 mm and a height of 450 mm to 500 mm, with a top flow-restricting cap having an outlet internal diameter of 40 mm, vertically fixed on a base through which the oxygen-nitrogen gas mixture can pass. The bottom is filled with glass beads of 3 mm to 5 mm diameter to a height of 80 mm to 100 mm. A metal mesh is placed above the glass beads to prevent falling burning debris from blocking the gas inlet and the gas distribution passage.
5.3 Specimen holder
A component capable of being fixed at the central axis position of the combustion tube and holding the specimen vertically. The contour of the specimen holder and its support shall be smooth to minimize turbulence in the introduced gas.
5.4 Gas control and measuring devices
5.4.1 Gas control device
A device for controlling the volume fraction of oxygen in the mixed gas entering the combustion tube, with a resolution of 0.1 %. At a gas flow rate of (40 ± 2) mm/s, the oxygen concentration adjustment accuracy shall not be less than ±0.2 %.
5.4.2 Gas measuring device
A device for measuring the volume fraction of oxygen in the mixed gas entering the combustion tube, with a measurement accuracy of ±0.1 %.
5.5 Gas supply system
The gas supply system consists of oxygen and nitrogen cylinders and pressure regulators. The oxygen shall comply with GB/T 3863, and the nitrogen shall comply with GB/T 3864. The gas operating pressure shall not be less than 1 MPa.
5.6 Igniter
A device made of a metal tube with a nozzle tip having an internal diameter of (2 ± 1) mm. The flame length is adjustable, and it can enter above the combustion tube to ignite the specimen. When the nozzle is directed vertically downwards, the flame length shall be (16 ± 4) mm. The fuel gas may be propane, butane, natural gas, etc.
For arbitration testing, propane without air mixing shall be used as the ignition gas.
5.7 Exhaust system
A system capable of removing smoke and ash particles generated by combustion, without affecting the gas flow velocity and temperature in the combustion tube.
5.8 Other equipment
5.8.1 Stopwatch
Accuracy ±0.5 s.
5.8.2 Vernier calliper
Accuracy 0.01 mm.
6 Test specimens
6.1 Specimen preparation
Test specimens shall be prepared in accordance with the relevant provisions of GB/T 1446.
6.2 Specimen dimensions
The specimen length shall be 70 mm to 150 mm, the width shall be (6.5 ± 0.5) mm, and the thickness shall be (3.00 ± 0.25) mm. Specimens of other thicknesses may also be tested, but the test results can only be compared for the same thickness.
6.3 Number of specimens
Not less than 15 specimens per group.
6.4 Appearance requirements
The appearance of specimens shall comply with the relevant provisions of GB/T 1446.
6.5 Conditioning and test environment
Conditioning and test environment shall be carried out in accordance with the relevant provisions of GB/T 1446.
