Fireproof Mesh Testing

Fire-resistant mesh testing mainly conducts scientific testing and analysis on fire resistance integrity, fire resistance insulation, dimensional stability, mechanical properties, corrosion resistance, and opening size and wire diameter, objectively assessing the product quality grade and issuing a detailed test report, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Fire resistance integrity: This is the most core performance indicator of the fire-resistant mesh, referring to the ability of the fire-resistant mesh to prevent flame from penetrating to the unexposed face within a certain time under standard fire conditions. During the test, it is observed whether continuous flaming appears on the sample and whether the cotton pad is ignited.

Fire resistance insulation: Refers to the ability of the average temperature rise and the maximum temperature rise of the unexposed face of the fire-resistant mesh not to exceed the specified limits under standard fire conditions. Usually, it is required that the average temperature rise does not exceed 140 ℃ and the maximum single-point temperature rise does not exceed 180 ℃, to prevent the heat transfer from igniting the combustible materials on the unexposed side.

Dimensional stability: Tests the dimensional change rate of the fire-resistant mesh under high temperature or long-term load. Excessive shrinkage or expansion may lead to enlarged installation gaps, losing the fire barrier function, or generating excessive stress in the frame leading to damage.

Mechanical properties: Including the tensile strength, elongation at break, tearing strength and joint firmness of the fire-resistant mesh. These properties determine whether it can maintain its structural integrity without tearing or falling off under high fire temperatures and possible impacts.

Corrosion resistance: Evaluates the corrosion resistance of the metal wires or coatings of the fire-resistant mesh in harsh environments such as salt spray and humidity. Corrosion will significantly reduce the strength of the metal wires and the integrity of the mesh body, thus affecting its long-term fire resistance effectiveness.

Opening size and wire diameter: Precisely measures the opening size of the fire-resistant mesh (such as the side length or diagonal length) and the diameter of the metal wire. These parameters directly affect its ability to prevent flame and high-temperature particles from penetrating, and are the basis for the product to comply with the design requirements.

Appearance and process quality: Checks whether the surface of the fire-resistant mesh is flat and free of defects such as broken wires, skipped wires, rust and stains, and whether the welding or weaving points are firm and uniform. Process defects may become weak points under fire conditions.

Testing Scope

Steel fire-resistant mesh: Usually woven from stainless steel wire or galvanized steel wire, with high strength, high-temperature resistance and good durability. The testing focus is on its oxidation and strength decay at high temperatures, and the high-temperature peeling resistance of the coating.

Stainless steel fire-resistant mesh: Made of austenitic stainless steel such as 304 or 316, with excellent corrosion resistance and high-temperature resistance. In addition to conventional items, special attention needs to be paid to whether sensitization occurs under sustained high temperatures, causing performance degradation.

Building fire-resistant guardrail mesh: Applied to the protective and fire separation facilities of stairwells, equipment platforms, atriums and other parts. Testing needs to combine its actual installation method and stress characteristics, evaluating its structural stability and fire resistance performance under fire conditions.

Ventilation duct fire-resistant mesh: A fire-blocking component installed where the central air conditioning and smoke control and exhaust system ducts pass through the fire separation zone. Testing needs to simulate the air flow and pressure conditions in the duct, verifying whether it can effectively block the spread of flame and smoke in the duct.

Cable tray fire-resistant mesh: Used to wrap or separate cable trays, preventing cable fires from spreading along the tray. Testing needs to consider the combustion characteristics of cables, evaluating its ability to block hot melt drips and flames.

Industrial equipment protection fire-resistant mesh: Applied in boiler rooms, chemical equipment rooms, generator rooms and other places, with both mechanical protection and fire resistance functions. Testing needs to consider special fire scenarios such as possible oil and gas fires, as well as the influence of corrosive environments.

Products of different fire resistance rating grades: According to the design requirements, the fire-resistant mesh needs to meet different fire resistance ratings of 0.5 hours, 1.0 hours, 1.5 hours, 2.0 hours and so on. The testing scope covers products of all grades, verifying their performance under the actual fire time-temperature curve.

Testing Methods

Standard fire test (fire resistance test): In accordance with the GB/T 9978.1 or ISO 834 standards, the fire-resistant mesh specimen is installed on a standard furnace, heated according to the standard time-temperature curve, and its integrity, insulation and other indicators are synchronously tested until the predetermined fire resistance time or failure.

High-temperature mechanical property test: A high-temperature universal testing machine is used. The fire-resistant mesh specimen or single wire is placed in a set high-temperature environment (such as 500 ℃ and 800 ℃) for a certain holding time, and then immediately subjected to a tensile test, obtaining its tensile strength and elongation data at high temperatures.

Salt spray test: In accordance with the GB/T 10125 standard, the fire-resistant mesh specimen is placed in a salt spray test chamber to simulate the marine or industrial atmospheric environment, and continuously sprayed for a certain period (such as 96 hours and 240 hours). After the test, its surface corrosion condition is checked and the residual strength is tested.

Dimension measurement and stability test: Precision measuring tools such as vernier calipers and projectors are used to measure the opening size and wire diameter at room temperature. For the dimensional stability, the specimen is placed in a high-temperature oven (such as higher than the working temperature) for constant temperature treatment, and after cooling, its dimensional change rate is measured.

Metallographic and composition analysis: A spectrometer is used to determine whether the chemical composition of the metal wire meets the material requirements. A metallographic microscope is used to observe the micro structure of the steel wire, the coating thickness and uniformity, evaluating its process quality.

Visual and tactile inspection: Under good lighting conditions, experienced inspectors carry out a comprehensive visual inspection of the finished fire-resistant mesh, supplemented by touch, to judge whether there are appearance defects such as broken wires, burrs, weak welding and obvious deformation.

Simulated installation state test: The fire-resistant mesh is fixed according to the installation method in the actual application (such as riveting, bolt fixing and embedding in the frame), and then load tests such as tension, compression and shear are carried out on a mechanical testing machine, evaluating the reliability of its installation joints.

Testing Standards

Domestic Standards:

1. GB/T 10125-2021, Corrosion tests in artificial atmospheres — Salt spray tests

2. GB/T 228.1-2021, Metallic materials — Tensile testing — Part 1: Method of test at room temperature

3. GB/T 229-2020, Metallic materials — Charpy pendulum impact test method

4. GB/T 230.1-2018, Metallic materials — Rockwell hardness test — Part 1: Test method

5. GB/T 232-2010, Metallic materials — Bend test method

International Standards:

1. ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature

2. ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Large fire resistance test furnace: The core equipment for testing the fire resistance performance of the fire-resistant mesh, with functions such as programmed temperature control, pressure measurement and multiple sensor interfaces. The size of the furnace chamber needs to accommodate components of the actual size and meet the requirements of the standard heating curve.

High-temperature mechanical testing machine: An electronic universal testing machine equipped with a high-temperature environmental chamber, which can carry out tensile, compression and bending tests on specimens in the range from room temperature to 1200 ℃, precisely recording the stress-strain curve at high temperatures.

Salt spray corrosion test chamber: Used to simulate the accelerated corrosion environment. The chamber body is made of corrosion-resistant materials, and has precise control functions for the solution pH value, chamber temperature, spray volume and settlement amount, to meet the test requirements of different standards.

Thermocouple and data acquisition system: K-type or S-type sheathed thermocouples are densely arranged on the unexposed face of the fire-resistant mesh, connected to a high-speed and high-precision data acquisition instrument, which monitors and records the temperature rise data in real time for judging the insulation performance.

Precision measuring instruments: Including digital vernier calipers, micrometers, tool microscopes or image measuring instruments, used to precisely measure the wire diameter, opening size and the dimensional change of the treated specimen, ensuring that the measurement accuracy reaches the 0.01 mm level.

Spectrometer: Such as a direct-reading spectrometer or X-ray fluorescence spectrometer, which can carry out rapid, non-destructive qualitative and quantitative analysis of the material composition of the metal fire-resistant mesh, ensuring that the material complies with the standard provisions.

Macroscopic and microscopic inspection equipment: Including high-brightness inspection lamps, magnifying glasses, stereomicroscopes and metallographic microscopes. They are used to systematically inspect the surface quality, weaving structure, welds and metallographic structure of the fire-resistant mesh from the macro to the micro level.