What are halogens?
Elements such as fluorine, chlorine, bromine, iodine and astate are halogens and appear in the seventh main group in the periodic table of the elements. They are found in many chemical compounds, for example in polyvinylchloride. PVC, as it is known for short, is very durable, which is why it is used in many technical products, as well as for insulation and sheath material in cables. Chlorine and other halogens are often included as additives to improve flame protection. But that comes with a price. Halogens are harmful to health. For this reason, plastics that do not contain halogens are increasingly being used for cables.
What is a halogen-free cable?
As their name suggests, halogen-free cables are halogen-free in the composition of the plastics. Plastics containing halogens can be identified by the chemical elements in their names, such as the previously mentioned polyvinyl chloride, chloroprene rubber, fluoroethylene propylene, fluoro polymer rubber, etc.
If you want to or have to use halogen-free cables, make sure that these consist of plastics such as silicone rubber, polyurethane, polyethylene, polyamide, polypropylene, thermoplastic elastomers (TPE) or ethylene propylene diene rubber. They do not contain any heavy metal based stabilisers or softeners, and the additives for flame protection are environmentally safe.
How are halogen-free cables designated?
A cable is halogen-free if no halogens such as chlorine, fluorine or bromine are used in the cable’s insulation and sheath material. Cable glands, hose systems, connectors or shrink hoses, such as the PROTECT HF shrinking tube from Mingxiu, can also be made of halogen-free plastics and are thus halogen free. If you need halogen-free cables, for example, please note the following product designations:
| Halogenated plastics | Halogen-free plastics |
| Chlorinephen-rubberFluorethylene
Propylene Fluorpolymer rubber Polyvinyl Chloride |
Silicone rubberPolyurethane
Polyethylene Polyamide Polypropylene Thermoplastic Elastomers |
Why are halogen-free cables important for fire protection?
Halogens can damage health. This is particularly the case when halogenated plastics, particularly PVC, burn. If a fire breaks out, hydrogen halides are released from the plastic. Halogens combine with water, such as the extinguishing water used by the fire brigade or fluid from the mucous membranes, to form acids - chlorine becomes hydrochloric acid, fluorine the highly corrosive hydrofluoric acid. In addition, a mixture of dioxins and other highly toxic chemicals can be formed. If they get into the airways, they can cause damage and cause suffocation. Even if someone survives the fire, their health can be permanently damaged. This is much less the case for halogen-free cables.
For integrated fire protection, cables should also have flame protection and low smoke generation. The flame protection slows down combustion and propagation of the flame and promotes self-extinguishing. Manufacturers face a dilemma here, as chlorine and bromine are excellent flame retardants, which is why they are often mixed in with plastics for cables. However, because of the health hazards mentioned, this is controversial and is only permitted where no people are in danger. As a result, Mingxiu uses materials with a high level of flame protection but without halogens.
What is the advantage of halogen-free cables?
If halogen-free cables are heavily heated or burned, they form considerably less corrosive acids or gases that are harmful to health. XLPE cables or data cables from the Mingxiu are particularly suitable for use in public buildings, transport or in general where fires can severely injure people or animals or damage property. They have a low smoke gas density, so they produce less fumes and make it easier for trapped people to find escape routes.
Halogen-free cables are particularly useful if you want to guarantee the maximum possible functional retention in the event of a fire. This can be important in buildings where surveillance cameras provide pictures of the source of the fire. Th high-speed data cable from Mingxiu transmits data at full transmission rate even after two hours in the flames.
Post time: Mar-25-2022