Definition
The vertical horizontal combustion tester is a specialized testing equipment used to evaluate the reaction performance of materials to ignition sources under specific conditions. It simulates the combustion behavior of the material after contacting the specified flame in the vertical or horizontal direction, and measures its combustion rate, afterflame time, afterburn time, and whether molten droplets occur. The equipment is widely used to evaluate the flammability and flame retardant properties of solid materials, and its design and testing procedures strictly follow relevant international and national standards to provide key data support for the safe application of materials.
Test Principle:
The test principle of the device is based on applying a standardized flame source to the material specimen and observing and recording its combustion process. In the vertical combustion test, the specimen is in a vertical suspension state, and the flame acts on the lower end of the specimen. In the horizontal combustion test, the specimen is placed horizontally and the flame acts on one end of the specimen. The core principle is to make the testing process repeatable and comparable by controlling the flame height, application time, and specimen size. The material undergoes thermal decomposition after heating, and the combustible gas produced mixes with oxygen in the air and burns under the action of the ignition source. The device quantifies the distance and time of combustion spread through precise timing devices and rulers, and then calculates the combustion rate. Its basic combustion rate formula can be expressed as:
v = L / t
where v represents the combustion rate, L represents the combustion spread length, and t represents the corresponding combustion time.
Measurement method
The measurement method strictly follows the provisions of standards such as UL 94, IEC 60695-11-10, GB/T 2408 and other standards. Before testing, the specimen should be adjusted in the specified temperature and humidity environment. During testing, the specimen is mounted on the corresponding specimen clamp, ensuring that it is in the vertical or horizontal position required by the standard. A Bunsen lamp or a specific blowtorch is used to produce a flame of a specified height, and the center of the flame is applied to the specimen at a standard angle and time. After removing the flame, use a stopwatch to record the flame burn time and flameless burn time of the specimen. At the same time, observe and record whether the combustion spreads to the reticle, whether molten droplets are generated, and whether the cotton wool underneath is ignited. Each set of tests needs to repeat a certain number of specimens, and the final results are graded according to the test phenomena of all specimens.
Influencing factors
The accuracy and repeatability of test results are influenced by a variety of factors. The thickness of the specimen is a significant factor, and different flame retardant grades may be obtained for different thicknesses of the same material. Material composition and uniformity, such as filler distribution and flame retardant content, directly affect thermal decomposition and combustion behavior. The cutting method and edge treatment during specimen preparation can affect the initial conditions for flame spread. Environmental conditions, including temperature, humidity, and airflow in the laboratory, should be controlled within standard limits to avoid interfering with the flame state and combustion process. Equipment factors, such as the calibration of burner caliber, gas purity and flow rate, and flame height, all need to be checked regularly. Consistency in operation, such as the angle, position, and timing of the flame application, requires rigorous training of the operator.
Applications
The vertical and horizontal combustion testing machine has a wide range of applications, mainly serving industries that require quality control and safety evaluation of the flame retardant properties of materials. In the electronic and electrical industry, it is used to test the flame retardant grade of wire and cable insulation sheath materials and plastic parts of electrical enclosures. In the automotive industry, it is used to test the combustion properties of interior materials such as seat fabrics and dashboard plastics. In the field of rail transit, it is used to evaluate the fire safety of materials inside carriages. In addition, this equipment is a key testing tool in the process of material development and formulation improvement in building materials, furniture fabrics, aerospace materials, and scientific research institutes, providing a scientific basis for preventing fire risks.
Equipment selection considerations
When choosing a vertical and horizontal combustion tester, it is necessary to consider many aspects. First, the specific standard system followed by the test should be clarified to ensure that the design of the equipment, such as the type of burner, specimen fixture, timing device, ruler range, etc., fully meets the requirements of the target standard. Secondly, consider the type and size range of the test materials to ensure that the equipment compartment volume and fixture configuration are compatible. The degree of automation of the equipment is another consideration, as manual equipment relies on operator timing observation, while semi-automatic or fully automatic equipment integrates automatic flame ignition, application, return, and electronic timing to reduce human error and improve efficiency. The safety performance cannot be ignored, and the equipment should have a stable gas control system, an effective smoke exhaust system and safety protection devices. Finally, the supplier's technical support capabilities, including installation training, calibration services, and spare parts supply, are of practical significance to ensure the long-term stable operation of the equipment.