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Flame retardant fabric flame retardant protective clothing test method

发布时间:2016-01-15 10:34:46  点击次数:0

Flame-retardant protective clothing refers to a protective suit that can slow down the spread of flame when it is in direct contact with flames and hot objects, and carbonize to form an isolation layer to protect human health and health. Every year, thousands of people in the world suffer from burns due to improper clothing. At the same time, it is found that the most serious burns are caused by the burning of clothes rather than the flame itself. The burns on the skin under burning clothes are often more serious than those directly exposed. . As a kind of human protective equipment to protect the safety and health of workers, flame retardant protective clothing is widely used in metallurgy, petrochemical, welding and other industries. With the improvement of people's safety awareness and protection knowledge and the development of domestic protective clothing production, The range of applications of fuel protective clothing has expanded.
The thermal protection performance of flame retardant protective clothing is generally determined by the flame retardant properties of the garment materials. In addition to flame retardant properties, the thermal insulation, integrity and liquid permeability of thermal protective clothing are also important indicators for determining the thermal protection performance of flame retardant protective clothing. Some technically developed countries such as the United States, Europe, Australia and other countries and regions have developed a more complete test method for assessing flame retardant properties. 1 American Fire Protection Association Standard
1.1 NFPA 1971 NFPA 1971 is a full set of equipment standards for firefighters in building fires, specifying minimum requirements for firefighters in building fires, including clothing design, safety features, and clothing components and accessories (tops, pants, helmets, gloves, Full inspection of footwear. Among them, the thermal protection performance test method (ie, TPP method) is to evaluate the thermal protection performance of the fabric by measuring the heat energy required to reach the human body through the surface of the fabric and other materials, resulting in secondary burn degree. The operation method is as follows: a heat source is placed on one side of the test sample, and a calorimeter is placed on the other side, and a movable heat insulation board is arranged between the heat source and the test sample, and the heat insulation board and the sample to be tested are usually insulated, and the heat insulation board is tested. Open, the test sample is exposed to the heat source, the heat flux of the sample is measured by measuring the thermal energy change of the calorimeter for a certain period of time, and the time required to reach the second degree burn is recorded, thereby measuring the thermal protection index of the sample. TPP value.
1.2 NFPA 1975 NFPA 1975 is a test standard for fire and emergency protective clothing, commonly used in the determination of the flame retardant properties of industrial flame retardant protective clothing. The flame retardant properties of protective clothing fabrics are tested by vertical burning test. In addition, the 500 °F oven test method is used to determine the thermal stability of the material. It is required to place the material in a high temperature oven at 500 °F for 5 min, wherein the shrinkage rate cannot exceed 15%, and then according to whether the material will ignite, melt or drip. Or decomposition to determine other thermal protection properties.
1.3 NFPA 2112 NFPA 2112 is the standard for industrial flame retardant protective clothing and is the experimental basis for the establishment of future industrial flame retardant protective clothing laws and regulations. It comprehensively describes the thermal protection performance requirements of industrial flame retardant protective clothing, including a series of thermal protection performance tests. (1) Vertical combustion performance test. After exposing the material to a standard flame for 12 s, remove the flame and determine if it will be ignited and burned to the length of the damage. (2) Test of protective performance of heat radiation and heat convection mixing, referred to as TPP method. The method test is to place a 6-square-inch fabric under a thermal convection and radiant heat source with a total energy density of 2 cal/(cm2•s), and then record the time required to reach the secondary burn. The TPP value is the time multiplication. Take the value of cal/cal/(cm2•s). The higher the TPP value, the stronger the protection provided by the fabric. Unlike the vertical burning test, the TPP test can tell us how much energy is absorbed by the human skin to achieve secondary burns through various fabrics. That is, the higher the TPP value, the higher the temperature and the high heat flame. The better the protection of the body, the unit TPP value is the most direct manifestation of thermal protection performance. (3) Thermal human body model test. The test is to put a 6-inch high mannequin with 122 temperature testers in the fireproof suit and expose it to a 2 cal/cm2·s heat source assembled by a 12-propane flamethrower. The data collected by a temperature tester simulates the secondary and tertiary burns and locations of human skin. This is the world's most advanced thermal burn assessment system of the same size as a real person. In order to further simulate the degree of burns in the actual flame, the test is used to test the degree of protection that the garment can provide under simulated actual flame conditions. Through this test, we can predict the level of secondary or tertiary burn that the body may achieve. The lower the systemic burn, the greater the chance of survival. (4) The thermal stability test is basically the same as the 500 °F oven test in the NFPA 1975 standard.
2 EU standards
2.1 EN 531 EN 531 is the European standard for industrial thermal protective clothing. This standard specifies the overall performance, structural design, dimensional stability, flame spread, heat and melting metal properties, size markings and hoes, user information, and identification patterns of flame retardant protective clothing. The flame retardant test method was carried out using EN 532. EN 532 is a test method for limiting the flame spread rate. The test method is to ignite the surface of the material placed vertically for 10 s. The criteria are as follows: (1) No sample should be burned to the edge of the fabric or the upper end of the fabric; () No sample shall be formed with holes; (3) No sample shall have combustion droplets or molten material falling; (4) The duration of refueling shall be less than or equal to 2 s; (5) The smoldering time shall be less than or equal to 2 s.
2.2 EN 470 EN 470 is the European standard for welders and similar types of thermal protective clothing. It specifies the design requirements, material requirements, safety requirements, size markings and hoes, user information, identification patterns, etc. After the sample is washed or dry-cleaned according to the prescribed method, the burning propagation property test of the fabric is carried out according to the EN 532 test method. In addition, the effects of falling metal droplets are evaluated in accordance with EN 348. After the test sample is washed or dry-cleaned, if the average drop of the drop on the 10 test samples is between 15 and 15.5 drops, then a second 10 sample test is performed, and the evaluation should be based on 20 swatches. The average data is subject to change.
2.3 EN 469 EN 469 is the European standard for fire protective clothing. It mainly considers the protection of heat and flame in large fires. It does not include special tasks such as removal of spilled chemicals, forest fires, close fire fighting, road accident rescue or special fire insurance. Clothing used in protection. The standard includes general requirements for protective clothing, important safety requirements, additional requirements, marking gimmicks, user information, and identification patterns. In addition to fire resistance, the outer fabric must also have certain physical properties to suit external environmental conditions such as thermal stress. These basic safety properties include residual strength, heat resistance, tensile strength, tear strength, surface wettability, and dimensional change. The standard requires that the outer layer be exposed to a heat source with a daily flow density of 10 kW/m2. The residual strength of the outer fabric, ie tensile strength and tear strength, must be greater than 450 N and 25 N, respectively. In addition, the standard also stipulates that any fabric used for protective clothing for firefighting must pass the heat resistance test. The test method is to place the sample in a constant temperature heating box at 260 °F. During the test, the sample cannot be melted, trickle or ignited and the shrinkage rate should be less than or equal to 5%.
3 Australian and Chinese standards
3.1 AS 4824-2001 AS 4824-2001 is the Australian (transitional version) firefighter protective clothing standard. The standard specifies the design requirements for the dressing of field and forest firefighters, sampling methods and pretreatment methods, thermal protection performance requirements, mechanical performance requirements, work efficiency and comfort requirements, general requirements, manufacturer information and marking gimmicks. Among them, the test method for thermal protection performance requirements is tested in a similar manner to EN 532.
3.2 GB 8965-98 GB 8965-98 is the national national standard for flame retardant clothing. This standard is applicable to industrial furnaces, metal thermal processing, welding, chemical, petroleum and other places. It is used when there is open flame or sparks or in the vicinity of molten metal, and when working in places with flammable substances and fire hazard. Flame retardant protective clothing. This standard refers to the industrial flame retardant clothing standard promulgated in 1988 with the same name standard and the international similar standard, and specifies the following aspects: the overall performance of the flame retardant protective clothing, the flame retardant performance of the fabric and the stitch, the flame retardant protective clothing Mechanical properties, structural design, processing, finished marking and packaging transportation, inspection methods, etc. The flame retardant test method of the fabric adopts GB/T 5455. The test method is similar to EN 532, which ignites the surface of the vertically placed material for 10 s, and then divides the fabric according to the test parameters of the after-burning time, the smoldering time and the damaged length. Three levels. After the flame retardant finishing of the fabric, the second grade is qualified, and the first grade is excellent. After 50 times of washing the test fabric, it should not be lower than the third grade. In the test, the product was found to have melt shrinkage as a non-conforming product.
4 Conclusion
China's flame retardant textile performance testing methods are moving closer to the internationally accepted standards, some are directly adopted, some are equivalent or equivalent, and the product standards are also developing towards internationalization and serialization. China's fire department has formed an industry series of standards for firefighters' general protective clothing performance requirements and test methods, fire insulation suits, fire escape suits and fire protection suits. At present, in terms of the comprehensiveness and multiplicity of performance requirements, textile protective product standards have been developed in terms of applicability in addition to flame retardancy requirements, such as fabrics with strong, breathable (wet), stiffness, shrinkage, color and Requirements such as toxicity. In addition, depending on the use environment, special protective performance requirements should be added. Welding equipment should increase the requirements for anti-melting metal droplet impact. Fire-fighting suits should increase the requirements for radiation resistance and water resistance. Petrochemical and coal mine protective clothing should increase antistatic properties. Wait for the request. With the advancement of technology, the improvement of people's awareness of safety and self-protection, and the introduction of relevant regulations, various high-quality protection products will be widely accepted by relevant industries, and their research will be deeper and deeper. Future protective clothing will continue to improve quality and reduce costs. It adopts new synthetic materials and integrates various protection functions such as fire prevention, anti-virus and anti-chemical, and develops into wearing comfort.
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