Flame retardant cables refer to cables that incorporate special materials and technical treatments during the design and manufacturing process to slow down or prevent the spread of flames when encountering a fire source. This type of cable achieves fire protection by adding flame retardants or other fire-resistant materials to the outer sheath, insulation layer or shielding layer of the cable. The use of flame-retardant cables can greatly improve the safety of buildings, vehicles and other important facilities. Especially when a fire occurs, it can reduce the losses caused by fire and buy time for personnel to evacuate.
Due to its unique design and manufacturing process, flame-retardant cables show significant advantages in a variety of applications. The following are the main advantages of flame retardant cables:
1. High safety: Flame-retardant cables can effectively inhibit the spread of flames in the event of a fire, thereby reducing losses caused by fires. This is especially important for crowded places (such as schools, hospitals, office buildings, etc.), which can buy valuable time for evacuation.
2. Low smoke and halogen free cable (LSOH cable): Many flame-retardant cables use low-smoke and halogen-free materials, which can release less smoke and almost non-toxic gases even when burning, reducing the harm to human health and improving Improved visibility to facilitate emergency evacuation.
3. Fire resistance: Some flame-retardant cables can not only prevent the spread of flames, but also maintain power transmission for a period of time under fire conditions, ensuring the normal operation of key equipment (such as fire protection systems, emergency lighting, etc.).
4. Environmental protection characteristics: Flame-retardant cables are usually made of environmentally friendly materials, which reduces environmental pollution. These materials are easily recyclable and meet the requirements of sustainable development.
5. Strong durability: Flame-retardant cables tend to have stronger mechanical properties and can withstand higher tensile and bending stress, extending the service life of the cable.
6. Wide adaptability: Flame-retardant cables are suitable for a variety of environmental conditions, including high temperature, humidity and even highly corrosive situations. They can maintain stable performance under various harsh conditions.
7. Comply with standards: Flame-retardant cables have undergone strict standard testing (such as UL94, UL1581 VW-1, etc.) to ensure their reliability and safety in practical applications.
8. Lower insurance costs: Because flame-retardant cables improve building safety, many insurance companies will offer lower insurance rates for buildings using such cables.
9. Easy to maintain: Flame-retardant cables are usually designed with ease of routine maintenance in mind, reducing maintenance costs and downtime.
Flame retardant cable application fields
Flame retardant cables are widely used in various occasions, especially in places with high fire safety requirements, such as:
Public buildings: hospitals, schools, shopping malls, office buildings, etc.
Transportation: subways, trains, airplanes, ships, etc.
Industrial facilities: chemical plants, refineries, power stations, etc.
Residential buildings: high-rise apartments, villas, etc.
Data center: server room, communication base station, etc.
Flame retardant cable testing standards
In order to ensure the quality and performance of flame-retardant cables, testing is usually carried out with reference to the following internationally recognized standards:
UL94: Evaluates the flame retardant properties of plastic materials, divided into V-0, V-1, V-2 and other levels.
UL1581 VW-1: Specifically used to test the overall flame retardant performance of cables, especially the vertical burning test.
IEC 60332: A cable flame retardant test standard developed by the International Electrotechnical Commission, covering different test methods for different types of cables.
Flame-retardant cables have become an indispensable part of modern construction and industrial applications due to their excellent flame-retardant properties, environmental protection characteristics and high safety. Whether it is a new project or an upgrade to an existing facility, choosing flame retardant cables is ideal for ensuring safety and improving efficiency.
Cable manufacturer TST CABLES provides an in-depth analysis of the comparison of UL94 and UL1581 VW-1 flame retardant grades, which is suitable for high-temperature cable manufacturers to conduct wire and cable testing.
There are 12 types in UL94: HB, V-0, V-1, V-2, 5VA, 5VB, VTM-0, VTM-1, VTM-2, HBF, HF-1, HF-2.
The UL94 flammability rating is the most widely used flammability performance standard for plastic materials. It is used to evaluate the ability of a material to extinguish after being ignited. There are many evaluation methods based on burning speed, burning time, anti-drip ability and whether the dripping beads burn. Many values can be obtained for each material being tested based on color or thickness. When selecting a material for a product, its UL rating should meet the thickness requirements for the wall portion of the plastic part. The UL rating should be reported together with the thickness value. It is not sufficient to report the UL rating without thickness.
The flame retardant grades of plastics increase step by step from HB, V-2, V-1, V-0, 5VB to 5VA:
HB: The lowest flame retardant grade in the UL94 standard. It is required that for samples between 3 and 13 mm thick, the burning speed is less than 40 mm per minute; for samples less than 3 mm thick, the burning speed is less than 70 mm per minute; or it is extinguished before the 100 mm mark.
V-2: After two 10-second combustion tests on the sample, the afterflame & afterburning were extinguished within 60 seconds. Dropping particles can ignite cotton.
V-1: After two 10-second combustion tests on the sample, the afterflame & afterburning were extinguished within 60 seconds. Dropping particles must not ignite cotton.
V-0: After two 10-second combustion tests on the sample, the afterflame & afterburning are extinguished within 30 seconds. Dropping particles must not ignite cotton.
5VB: After five 5-second combustion tests on the sample, the afterflame & afterburning are extinguished within 60 seconds. Dropping particles must not ignite cotton. Burn-through is allowed for bulk samples.
5VA: After five 5-second combustion tests on the sample, the afterflame & afterburning are extinguished within 30 seconds. Dropping particles must not ignite cotton. Block samples are not allowed to be burned through.
Wire burning methods in UL1581:
1. VW-1: Vertical burning test (UL wire burning level)
2. FT1: Vertical burning test;
3. FT2: Horizontal burning test;
4. FT4: Vertical burning test;
5. FT6: Horizontal burning and smoke test. (The combustion level of FT type is the CSA standard wire burning level) Among the above levels: VW-1 and FT1 are the same level. FT2 is the easiest to pass and has the lowest level. (FT6>FT4>FT1>FT2); VW-1 is stricter than FT1. Both are vertical combustion. Judgment criteria:
1. The burning mark (kraft paper) cannot be carbonized by more than 25%;
2. The afterburning time of five 15-second combustions cannot exceed 60 seconds; 3. Burning drippings cannot ignite cotton; VW-1 requires meeting 1, 2, and 3; FT1 only requires meeting 1 and 2 for the wire industry. : UL 94’s V-2, V-1, V-0, 5VA, and 5VB assess the materials used in wires. During testing, standard samples must be prepared with additional test materials and will not be marked on the wires. VW-1 VW -2 FT-1 FT-2 assesses the wire itself. After passing the test, the corresponding grade can be marked on the wire.
The flame retardancy of wires and the flame retardancy of UL94 are two completely different things. For example, an insulating material can pass V-0 of UL94 but may not pass VW-1; in addition, UL94 is the flame retardancy of insulating materials. The flame retardant requirements for wires are generally in UL758 62 1581; the objects are different; so the flame retardancy in UL94 such as V-0 V-1 is not the flame retardancy of wires at all; there is no “V-0” printed on AWM wires !
There is a big difference in equipment between VW-1/FT1 and UL94 V0 combustion test:
1. The height and temperature of the flame are different
2. The methane flow rate used in the test is also different.
3. The back pressure of methane is also different
4. The volume of the combustion box is also different: VW-1 requires more than 4 cubic meters, while V0 only requires more than 0.5 cubic meters. 5. The number of combustions is also different. 6. In the combustion results: V0 requires recording the residual burn time, while VW-1 Need not!
However, the test conditions and test methods of 5V class combustion and VW-1 combustion in UL94 are similar, relatively close!
TST CABLES reminds everyone: Whether it is VW-1 or UL94 combustion test equipment, you must refer to ASTM5025 and ASTM5027. UL1581 and UL94 are just test methods. The requirements for test equipment must be in accordance with ASTM standards!
UL94 and UL1581 VW-1 flame retardant grade test comparison
UL94 and UL1581 VW-1 are two different flame retardant grade standards, which are suitable for different materials and application fields. Here is a brief comparison of the two standards:
UL94 flame retardant rating
UL94 is a flame retardant performance testing standard for plastic materials that mainly evaluates the reaction of plastic materials when exposed to flame or heat. This standard applies to various plastic products, including electrical casings, electronic equipment parts, etc.
Test methods: UL94 testing includes a variety of test methods, such as V-0, V-1, V-2, 5VA, 5VB, etc. Among them, V-0 is one of the most common grades. It requires that the flame of the sample extinguishes itself after being ignited twice, and no dripping material is allowed to ignite the tissue paper below.
Scope of application: Mainly used to evaluate the flame retardant properties of plastic materials themselves. These materials may be used to make insulation layers or sheaths for wires and cables.
Marking: Materials that pass UL94 testing will usually have the corresponding rating marked on the product, such as “UL94 V-0”.
UL1581 VW-1 flame retardant rating
UL1581 VW-1 is another standard specifically used to evaluate the flame retardant performance of wires and cables. It focuses on the flame retardancy of the entire cable assembly rather than just the material.
Test method: The VW-1 test method is to place the cable vertically and apply a flame to observe whether the flame can extinguish itself within the specified time. The cables that passed the test showed they could slow the spread of flames in the event of a fire.
Scope of application: Mainly used for the overall flame retardant performance evaluation of wires and cables. It is suitable for various types of wires and cables, especially those used in public places, such as internal wiring of buildings.
Marking: Cables that pass the UL1581 VW-1 test can have the flame retardant grade marked directly on their surface.
Comparison summary of UL94 and UL1581 VW-1 flame retardant grade testing
Test object: UL94 mainly tests plastic materials, while UL1581 VW-1 tests the entire cable.
Test method: Although both are flame retardant tests, the test methods are different. UL94 focuses on whether the material can self-extinguish, while UL1581 VW-1 pays more attention to the performance of the cable when burning vertically.
Scope of application: UL94 is suitable for the flame retardant performance evaluation of plastic products, while UL1581 VW-1 is for the flame retardant performance of cable products.
Give an example
A plastic insulation material may pass the UL94 V-0 test, which means that the material itself has good flame retardant properties.
However, this does not mean that wires and cables made of this material will definitely be able to pass the UL1581 VW-1 test, because the flame retardant performance of the cable is also affected by other factors, such as conductors, insulation layers, sheaths and other components. interaction.
Therefore, when selecting materials or cables, you should determine whether you need to comply with a certain standard based on the needs of the actual application, and ensure that the selected materials or products meet specific flame retardant requirements.
In today’s rapidly developing society, safety always comes first. TST CABLES launches a new range of flame retardant cables – providing the highest level of safety for your buildings and facilities. Using advanced material technology and strict quality control, our flame retardant cables have passed UL94 and UL1581 VW-1, IEC 60332 flame retardant grade tests, and comply with industry standards of various countries. Very little smoke and harmful substances are released, maximizing the protection of people’s lives and property from damage. Whether it is an important transportation hub, industrial equipment, commercial building, hospital, school or family home, TST CABLES’ flame retardant cables can provide you with reliable and long-lasting electrical connection solutions. Choose TST CABLES’ flame-retardant cables and let our professional technology and excellent quality protect the electrical safety of every project and equipment of yours.
If you have customized flame retardant cables, low smoke halogen-free cables, extruded polyimide (PI) cables, UL cables, Teflon wires, armored wires, industrial cables, power cables, control cables and other products, and need further technical support or cable solutions, you can visit the TST CABLES official website, or you can send an email to the professional cable engineer of TST cable manufacturer at any time (email: lixiangchao@testeck.com, please state your country, your industry, and your needs in the email, we can also provide you with free samples).
