The scope of application of flame-retardant wire and cable, which is better, flame-retardant cable or fire-resistant cable?
Although the flame-retardant cable is not as good as the fire-resistant cable, it can continue to run smoothly without being burned out under the high temperature of the fire, but it can prevent the spread of the fire, keep the fire within a limited range, keep other various equipment, and avoid causing greater damage. Loss. So which is better, flame retardant cable or fire resistant cable? Let's find out together.
一、 What is a flame retardant cable？
The general method used for flame-retardant cables is to add halogen-containing halides and metal oxides to the sheath material. In the event of a fire, it can quickly prevent or delay the occurrence of flames and the spread of fire.
Performance characteristics of flame retardant cables:
1. Low toxin
The insulation and sheath of the new flame-retardant cable do not contain heavy metals such as lead and cadmium that are harmful to the human body, and will not pollute the living environment during use and disposal, and have high safety performance.
2. Halogen free
The new environmentally friendly flame retardant cable uses a green insulating layer and a special oxygen barrier material, which has good electrical properties, physical and mechanical properties, and the product does not contain halogen, which effectively solves the "secondary pollution" in combustion . It is of great help to air and personal safety.
3. High flame retardancy
Environmentally friendly cables can fully guarantee the building requirements for high fire protection requirements. In the event of a fire, the cable is not easy to burn, and the flame-retardant cable can prevent the burning flame, effectively controlling the spread of the fire and the loss and personal safety.
4. High transmittance
When the cable burns, it does not produce a lot of smoke like other cables when it burns, which is more conducive to the evacuation of personnel and the execution of fire fighting. Compared with the light transmittance of traditional flame-retardant cables less than 20%, the light transmittance of new flame-retardant cables greater than 50% is more advantageous.
5. No corrosive gas
The new type of cable uses a new type of special coating material, which has no pollution to the environment, and does not produce harmful or toxic gases during its production and use, and it emits very little acid gas during combustion. Not even, more environmentally friendly and reliable.
6. Easy installation and operation
The new flame-retardant cable is more convenient during use, and the installation operation is simpler and faster.
二、 Classification and application of flame retardant cables
1. Ordinary flame retardant wire and cable
Ordinary flame-retardant wire and cable insulation and sheath materials generally use halogen-containing (or modified by adding halogen-containing flame retardants) polymer materials, and the most commonly used material is polyvinyl chloride (PVC). Ordinary PVC resin has extremely high electrical insulation, chemical resistance, abrasion resistance, aging resistance, and low price. It has become the most widely used cable material raw material in my country. However, when PVC is burned, it will release hydrogen chloride, Toxic and harmful gases such as carbon monoxide, carbon dioxide, various aromatic hydrocarbons, and chlorine-containing compounds.
2. Low-smoke flame-retardant wire and cable
For low-smoke flame-retardant wires and cables, inorganic hydroxide flame retardants such as aluminum hydroxide and magnesium hydroxide can be added to the insulation and sheath materials. As flame retardants, aluminum hydroxide and magnesium hydroxide have the advantages of non-toxicity, non-volatility, low price, flame retardancy and smoke elimination. Moreover, it has poor compatibility with the matrix resin. When used as a flame retardant, it must be added in large quantities to achieve a certain level of flame retardancy. Adding a large amount will easily lead to a decrease in the material's molding processability and mechanical properties.
3. Low-smoke and halogen-free flame-retardant wire and cable
The insulation and sheath materials of low-smoke and halogen-free flame-retardant wires and cables are mostly thermoplastic elastomer materials. The materials do not contain halogen elements such as fluorine, chlorine, bromine, and iodine, so they cannot continuously generate flammable gases, so they burn and self-extinguish. For example, when the flame retardant material is heated or burned, it can be melted, and when the molten material drips, most of the heat can be taken away, so that the combustion is delayed, and finally the combustion may be terminated.
4. Fluoroplastic flame retardant wire and cable
Fluoroplastic flame retardant wires and cables are inherently flame retardant due to the special chemical structure of their materials. This material does not need modification or flame retardant treatment, and has the characteristics of high temperature resistance, oxidation resistance, non-flammability, high oxygen index, self-extinguishing, etc. It is an ideal wire for optical fiber communication cables.
三、 Specifications and models of flame retardant cables
The model code of the flame-retardant cable is ZR, and different marks will be written on the back of the code according to the materials used in the cable. For example, V means that the insulator material of the cable is polyvinyl chloride, X means that the insulator material of the cable is rubber, L means that the conductor material of the cable is aluminum, T is copper, and V means that the inner sheath material of the cable is polyvinyl chloride ethylene.
四、Which is better, flame-retardant cable or fire-resistant cable?
1. The characteristic of flame retardant cable is to delay the spread of flame along the cable so that the fire will not expand. Because of its low cost, it is a cable variety widely used in fireproof cables. Whether it is a single cable or a bunch of laying conditions, the flame spread can be controlled within a certain range when the cable burns, thereby avoiding major fire disasters and improving the fire protection level of the line.
2. The fire-resistant cable can maintain normal operation for a certain period of time under the condition of flame burning, and can maintain the integrity of the line. When the fire-resistant cable is burned, the amount of acid gas smoke is less, and the fire-resistant and flame-retardant performance is greatly improved. Especially when burning, accompanied by water spray and mechanical blow, the cable can still maintain the complete operation of the line.
3. When the fire-resistant cable is burning, the cable line can still maintain normal operation for a certain period of time. This is the fundamental reason why fire-resistant cables can replace flame-retardant cables, but flame-retardant cables cannot replace fire-resistant cables.