Technical Analysis of Horizontal and Vertical Combustion Tester: Determination of Flame Propagation and Combustion Rate

The horizontal and vertical combustion tester is the core equipment for evaluating the flame retardant performance of materials. By simulating the interaction between flames and materials, it accurately measures the flame propagation distance and combustion rate, providing key data support for material fire rating determination (such as UL94, GB2408 standards). The core of its technology lies in the quantitative analysis of flame dynamic behavior and combustion process.

1、 Testing principle: The essence of flame propagation and combustion rate

The flame retardancy of materials can be characterized by the spread speed and sustained combustion ability of flames on the surface.Horizontal and Vertical Combustion TesterBy controlling a standard flame (usually methane or propane, flame height 20-125mm, energy 50-150W) to burn the sample (horizontally or vertically placed) for a specific time (such as 10-30 seconds), observe and record the following key parameters:

Flame propagation distance: the horizontal/vertical length from the ignition point to the farthest position of the flame front, reflecting the material's ability to suppress flame propagation;

• Burning rate: the distance of flame propagation per unit time (such as mm/s), which directly reflects the decomposition rate and flammability of the material after heating;

• Continuation time: the duration (in seconds) of self ignition of the material after removing the external flame, related to its self extinguishing performance;

• Ignitivity of Droplets: Whether the molten droplets generated during combustion ignite the degreased cotton below (assess the risk of secondary fire).

2、 Technical Implementation: From Flame Control to Data Collection

The testing instrument achieves precise testing through precision machinery and sensing systems

• Flame control module: using a gas flow control valve (accuracy ± 1%) and a high-precision timer to ensure that the flame height (such as 20mm ± 1mm) and action time (such as 10s ± 0.5s) strictly meet the standards; The fine adjustment function of flame angle (usually 45 ° to the sample surface) and position (2mm from the edge of the sample) can eliminate operational errors.

Sample fixing device: In horizontal mode, the sample is placed horizontally (simulating planar combustion, such as plastic film); In vertical mode, the sample is fixed vertically (simulating vertical combustion, such as electronic device casings), and the fixture needs to ensure that the sample's verticality deviation is less than 1 ° to avoid interference from gravity on flame propagation.

Data acquisition system: Record the real-time position of the flame front through a high-speed camera (frame rate ≥ 100fps) or a high-temperature resistant ruler (scale 0.5mm), analyze the flame propagation curve (distance time function) with software, and calculate the combustion rate; Simultaneously monitor the ignition time (through infrared sensors or manual timing) and droplet trajectory (assisted by high-speed cameras to determine whether the cotton has ignited).

3、 Application value: Quantitative basis for flame retardant performance

The test results are directly related to the actual fire resistance performance of the material - for example, in the UL94 standard, if the sample has a continuous combustion time of ≤ 10 seconds and no droplets ignite the degreased cotton during the vertical combustion test, it is judged as V-0 level (higher flame retardant level); If the combustion rate is too fast (such as>100mm/s) or the flame propagation distance is too long (such as exceeding the specified limit), the material needs to adjust the formula (such as adding flame retardants) or optimize the structural design.

　　Horizontal and Vertical Combustion TesterBy accurately controlling flame parameters and quantifying flame propagation dynamics, it provides "measurable, comparable, and optimizable" technical support for material flame retardancy, and is a key detection tool for ensuring fire safety in fields such as electronics, transportation, and building decoration.