Flame Retardant Testing of Building Materials Combustion Test

Comprehensive Analysis of Flame Retardant Testing

Testable Samples

The range of samples for flame retardant testing is extensive, covering various types of flame retardant materials, including organic flame retardant materials, inorganic flame retardant materials, polymer-based flame retardant materials, composite flame retardant materials, halogen-free flame retardant materials, halogen-containing flame retardant materials, phosphate ester flame retardant materials, as well as nitrogen-based flame retardant materials, silicon-based flame retardant materials, polyurethane flame retardant materials, polyester flame retardant materials, rubber flame retardant materials, fiber flame retardant materials, glass fiber flame retardant materials, metal oxide flame retardant materials, nano flame retardant materials, natural flame retardant materials, synthetic flame retardant materials, high-performance flame retardant materials, environmentally friendly flame retardant materials, liquid flame retardant materials, intumescent flame retardant materials, dry powder flame retardant materials, and gaseous flame retardant materials.

Testing Items and Methods

Common Testing Items

Combustion Performance Related: Includes ignition, burning rate test, flame spread test, burning time test, flame persistence test, flammability test, and burning extensibility test, used to evaluate various characteristics of materials during combustion, such as the speed and range of flame spread, and the time from ignition to complete combustion.

Oxygen Limitation and Thermal Performance Related: Limiting Oxygen Index (LOI) test and oxygen index test measure the material's ability to sustain combustion at different oxygen concentrations; Heat Release Rate (HRR) test, thermal degradation temperature test, thermal stability test, heat resistance test, and high-temperature resistance test focus on the material's performance under heat, such as the rate of heat release, the temperature at which decomposition begins, and stability in high-temperature environments.

Other Performance Related: Smoke density test measures the concentration of smoke produced during material combustion; Drip test, ash test, combustion residue test, combustion product analysis, gas release test, and gas emission test analyze the products and emissions after material combustion to assess their toxicity and environmental hazards.

Specific Testing Methods

Limiting Oxygen Index (LOI) Test: Determines the minimum oxygen concentration required for a material to sustain combustion under controlled oxygen conditions, thereby evaluating the material's flame retardant properties.

Vertical Burning Test: Tests the combustion performance of materials in a vertical position, evaluating their flame spread characteristics. Commonly used for testing wires and cables, automotive interior materials, textiles, etc. Each group requires five samples, which must be smooth and free of bubbles, with dimensions of 125±5mm in length, 13.0±0.3mm in width, and 3.0±0.2mm in thickness. The test is conducted in a specific combustion chamber.

Horizontal Burning Test: Tests the combustion characteristics of materials in a horizontal position, measuring the burning rate and flame spread. Suitable for testing materials such as wires and cables, plastics, leather, and blankets. Similarly, five specimens are required for each material, with specifications identical to those for the vertical burning test. The test is conducted in a laboratory combustion chamber. This method can also test samples with thicknesses of 2-13mm, but results can only be compared between samples of the same thickness.

Smoke Density Test: Measures the concentration of smoke produced during material combustion, evaluating its impact on visibility.

Testing Standards

China has two main national standards for flame retardant products: GB20286-2006 "Requirements and Marking for Combustion Performance of Flame Retardant Products and Components in Public Places" and GB "Classification of Combustion Performance of Building Materials and Products." According to the correspondence between the combustion performance grades of building products and their combustion performance, except for flooring materials, building products are divided into seven levels, from highest to lowest: A1, A2, B, C, D, E, F; flooring materials are also divided into seven levels, from highest to lowest: A1fl, A2fl, Bfl, Cfl, Dfl, Efl, Ffl.

In addition, there are other specific standards, such as GB/T1844.4-2008 "Plastics—Symbols and Abbreviated Terms—Part 4: Flame Retardants," GB/T4294-2010 "Aluminum Hydroxide," GB/T5454-1997 "Textiles—Burning Behavior—Oxygen Index Method," etc.