Magnesium hydroxide replacing organic bromine: a case study of environmental transformation of power cables
Although organic bromine flame retardants widely used in traditional cables have good flame retardant properties, they release toxic and harmful gases during combustion, seriously threatening personnel safety and causing long-term pollution to the environment. With the increasingly strict environmental regulations and the improvement of public safety awareness, more and more cable manufacturers are seeking more environmentally friendly and safe alternative solutions.
1、 Limitations of Organic Bromine Flame retardants
In the past few decades, organic bromine flame retardants have been widely used in the insulation layer and sheath materials of power cables due to their efficient flame retardant properties. However, this material has several obvious drawbacks:
Burning produces toxic gases
Under fire conditions, the thermal decomposition of organic bromine based flame retardants will produce a large amount of hydrogen halide gases (such as hydrogen bromide), which not only have a strong irritating odor, but also have a strong corrosive effect on the human respiratory tract and eyes, easily causing secondary damage.
Generating thick smoke that affects evacuation
When organic bromine materials are burned, they will produce thick black smoke, obstruct the line of sight, reduce visibility, and seriously affect personnel evacuation and fire rescue.
Environmental pollution issues are prominent
The residue of flame retardants after combustion may contain persistent organic pollutants such as dioxins, which can cause long-term harm to soil, water sources, and ecosystems.
It is precisely because of the above issues that the EU RoHS directive, REACH regulation, and China's "Management Measures for the Restriction of Hazardous Substances in Electrical and Electronic Products" have put forward clear restrictions on the use of organic bromine flame retardants. This also prompts cable companies to accelerate their search for environmentally friendly alternatives.
2、 Environmental characteristics and flame retardant mechanism of magnesium hydroxide
Magnesium hydroxide is a natural mineral material that can be used as a high-performance inorganic flame retardant after fine processing. It has the following environmental and safety advantages:
Completely halogen-free
Magnesium hydroxide does not contain any halogen elements and does not release hydrogen halide gas during combustion, fundamentally avoiding the harm of toxic gases.
Low smoke non-toxic
During combustion, it mainly releases water vapor and a small amount of magnesium oxide, producing almost no smoke, greatly improving the safety of the fire scene.
Green and environmentally friendly
The material itself is an inorganic mineral with a wide range of sources, and the production and use processes are pollution-free, in line with the concept of sustainable development.
Stable flame retardant effect
Magnesium hydroxide begins to absorb heat and decompose at around 340 ℃, and continues to transform at around 500 ℃, effectively delaying the spread of fire and improving the fire resistance time of cables.
3、 Case Analysis of Environmental Protection Transformation Practice for Power Cables
Taking a large wire and cable manufacturing enterprise as an example, under the promotion of the national "dual carbon" strategy, the enterprise has launched an environmental upgrade plan for a full range of power cable products, with the goal of completely phasing out organic bromine flame retardants and using magnesium hydroxide as the main flame retardant component.
Product structure optimization
The enterprise will ｒｅｐｌａｃｅ the original polyvinyl chloride (PVC) and halogenated cross-linked polyolefin materials with halogen-free flame-retardant polyolefin materials filled with magnesium hydroxide, and adjust the formula to ensure that the cable has good mechanical and electrical properties.
Process improvement
Considering that magnesium hydroxide powder is heavy and has poor flowability, the company has introduced a high dispersibility masterbatch process to evenly distribute the filler in the substrate, improving the consistency and stability of the finished cable.
Excellent performance test results
According to third-party testing agencies, the new generation of cable products using magnesium hydroxide meet or exceed international standards in vertical combustion testing, smoke density testing, and toxic gas release, especially in fire simulation experiments.
Good market response
After the launch of the new product, it quickly gained recognition in high-end markets such as subways, hospitals, and data centers. Customer feedback stated that it is more secure in installation, maintenance, and emergency response, while meeting green procurement needs.
4、 Technical challenges and response strategies for replacing organic bromine systems with magnesium hydroxide
Although magnesium hydroxide has significant environmental advantages, it still faces some technical challenges in practical applications:
A large filling amount affects material properties
In order to achieve the desired flame retardant effect, magnesium hydroxide usually requires a high addition ratio, which may lead to problems such as decreased material flexibility and weakened tensile strength. In this regard, enterprises have improved by optimizing composite systems and adding toughening agents.
High temperature control requirements for processing
Magnesium hydroxide undergoes dehydration reaction at high temperatures. If the processing temperature is too high, it may cause rapid evaporation of water, resulting in material foaming or surface defects. Therefore, it is crucial to set a reasonable extrusion temperature curve.
The cost is slightly higher than traditional materials
Compared to organic bromine flame retardants, magnesium hydroxide raw materials are more expensive, but due to their long service life and low maintenance costs, their overall cost-effectiveness is higher in terms of their lifecycle.
In addition, with the development of nanotechnology and surface modification technology, the dispersibility, compatibility, and processing performance of magnesium hydroxide are expected to be further improved, thereby expanding its application range in high-performance cables.