Frequent electric fire behind: halogen free flame retardant materials is the key
As urban development accelerated, cars are also rising. Lead to abnormal urban traffic congestion, but also constructs the environmental pollution, human has created in recent years, with the national environmental protection and vehicle purchase policy, making a large number of consumers want to buy car to temporarily turned to civilian vehicles, electric bicycle.
Electric bicycle with its convenient, efficient, environmental protection, and many other advantages to get ordinary people's love, in the ten years of development in the process of ownership with more than 140 million vehicles. However, with the improving of the ownership, recent events on electric car burst into flames are occurring in all parts of the country, especially in the hot summer, even more so.
On May 15, three of the northwest edge of the whole railway network culture road of zhengzhou city antai jin yuan village fire, more than 10 electric cars burned, next to two car paint are baked, but caused no casualties.
On June 25, henan zhengzhou, for a district to pull wires for electric bicycle charging, fire, 15 killed and two wounded.
On July 1, henan zhengzhou city wen's road of the sweet orange protuberant fires in the district, the scores of storage battery and the bike was burned down.
On August 12, henan zhengzhou jmbilly company employees a recharging electric moment was burned into a skeleton.
On October 12, henan zhengzhou garden north road, vocal by electric charge on fire, a 10 layer houses under construction there is a fire, because of the crowded, many people ran out, the accident killed one woman and five minor injuries.
Henan electric cars were too numerous to the frequency of accidents of the fire, actually not only is this year, long ago, henan had frequent battery car accident. Since 2008, the total of electric bicycle in henan province 1336, fire killed 40 people and injured 35, electric bicycle fire), the number of casualties are on the rise. By the end of October this year a total of 486, these fires is greater than the sum of last year.
Electric fire death cause in the material
Relevant personage says, electric fire accident and the electric main non-standard production, maintenance and related charge.
Some people think that some inferior electric car charger in order to save costs, insufficient input and output the wire line diameter, outer shell plastic material flammable not heat-resisting, after the rechargeable battery is full, continue to large current charging rechargeable battery, easy to cause the line of fire, or in the battery heating.
A large electric bicycle in Shanghai fire simulated experiment, three storage battery was lit after simple treatment, send out a lot of car plastic parts in high temperature smoke, the scene moments over the black smoke, people even wear protective gear, also can't close. Three minutes later, the center of the fire temperature reached 700 ℃, instantaneous can reach 1000 ℃, the plastic burning gas and battery explosion, let a person cannot escape.
A lot of casualties is not caused by flame directly, deadly smog often greater than open flame. At present, almost all electric bicycle use components, are flammable materials, fire can quickly form of flue gas, once inhaled, will lead to a loss of self-help capacity.
And the electric car industry has been in use in 1999 on the implementation of the electric bicycle general technical conditions, some technical indicators did not make clear a regulation. Due to the current national standard nor fire index in the provisions of the fire prevention electric cars mostly do not good, such as electric cars use plastic shell, once the spontaneous combustion, plastic shell will quickly burn, will produce harmful gas. If electric cars shell use flame retardant materials, the line to do some flame retardant treatment, even if the short circuit caused a fire, but because of flame retardant treatment can prevent electric car spontaneous combustion.
Halogen-free flame retardant materials is a hot spot
It is understood that the current domestic most electric materials are mainly ABS engineering plastics, polyurethane material, itself does not have the plastic material flame retardant properties, and the combustion will produce a large number of harmful substances, this also is the important cause leading to the storage battery fire high mortality. So what kind of material can replace electric current implementation effective flame retardant and not toxic harm the human body?
In traditional process, the key raw material used for flame retardant is halogen, but after burning halogen will emit the harmful gas such as dioxins and caused great pollution to the environment. So for an environmentally friendly flame retardant electric materials, it had no halogenated flame retardant materials become critical, and engineering plastics with halogen free flame retardant is the hot point in hot spots.
ABS halogen-free flame retardant materials
Since the electric motor is ABS engineering plastics in the majority, then we will start with ABS plastic, ABS is - acrylonitrile - butadiene styrene terpolymer, excellent mechanical properties, processing performance and chemical stability, widely used in electrical and electronic, automobile and aerospace and other high-tech fields. But, ABS is burning, limit oxygen index was only about 18.0 to 18.8; When it burns, release a large amount of toxic gases. Traditional containing halogen flame retardant, combustion will produce a large number of poisonous and harmful strong excitant gas, to people's health and environment directly, potential and long-term damage.
Phosphorus - nitrogen expansion type flame retardant is the most favored by people and has engineering application prospects of one of the new high efficiency, non-toxic, flame retardant system. Expansion effect needs three main components: acid source, carbon source and gas source. As the source of acid decomposition, carbon source, source of dehydration carbonized, foam decomposition gas expansion synergy, such as the carbon layer to make flame retardant polymer burning surface to form a layer of fluffy porous carbon layer and trap the heat transfer and diffusion of oxygen, effectively delay and prevent the thermal degradation of polymer, inhibits the generation of volatile combustible components, so as to achieve the purpose of the flame retardant.
Pu halogen-free flame retardant material
Polyurethane as a conventional polymer materials, the performance is very outstanding, but the regular polyurethane material is easy to burn, in industries such as automotive interiors and household need do flame retardant with polyurethane. Regular polyurethane flame retardant treatment is a physical add packing, because the requirements of environmental protection, mainly is given priority to with halogen free flame retardant filler.
At present, the halogen-free flame retardant thermoplastic elastomer that sells on the market with melamine urinary cyanate and phosphate composite flame retardant, flame retardant, such as the preparation of inorganic magnesium aluminum, the former processing performance is poor, and prone to migration; While the latter at the expense of the flexible elastomer, greatly limits its application in various fields. The expansion type flame retardant production of halogen free flame retardant thermoplastic elastomer, can get excellent flame retardant performance at the same time, the basic retain the thermoplastic elastomer, plastic, has a wide application field and good market prospects.
Halogen-free flame retardant polypropylene material
According to market research report, issued by the PersistenceMarketResearch global low smoke zero halogen flame retardant polypropylene market is expected to reach $664 million in 2020. PP in building, automobile, electronic products, such as the main terminal demand rising in the field of application, this is still driving the global low smoke zero halogen flame retardant PP market one of the key factors. Public for halogen toxicity, fire safety and environmental protection problems focus on growing, the low smoke zero halogen flame retardant PP market growth brings positive impact.
Poly petrochemical study of halogen free flame retardant PP with flame retardant is a kind of expansion type of halogen-free flame retardant, mainly through the condensed phase. At lower temperatures, the flame retardant can produce acid can be used as dehydrating agent; At a slightly higher temperature, acid promote dehydration reaction of PP, and the system in the process of the melt; Dehydration of water vapor and the non-combustible gases produced by PP thermal decomposition has in the molten state of the system expansion foam; Meanwhile, PP ester base in dehydration, carbide form inorganic substances and carbon residue, and the foam system further; Reaction nearing completion, the system of gel and cure, the final formation of porous carbon foam layer.
Selective use of halogen free flame retardant materials
Since the halogen-free flame retardant materials, electric why not? An electric group wuxi region, said an official with the product generally do light electric shell plastic only more than 400 degrees Celsius, the current in the electric car industry itself under the condition of profit space is limited, manufacturers no incentive to study with a new non-flammable material to make electric cars shell.
And the halogen-free flame retardants used in engineering plastics, some companies in China are copied, the product cost has obvious advantages, but due to the synthesis process remains to be further perfect, the product still exists the problem of the heat, so the domestic modified plastics factory in the chosen alternative products, tend to be more discreet, demand is high, the price is ok still adopts imported flame retardant products, and low demand, the price is cheap, choose domestic substitutes, this will also lead to a good flame retardant material prices problem.
So, the cost and the high threshold limit the electric car companies choose halogen-free flame retardant materials as a substitute for general materials, however, as the electric fire frequency and the attention of the authorities, this phenomenon is expected to be improved.
On Nov. 2, in order to strengthen the electric bicycle fire safety management, effectively prevent and curb electric bicycle fire accident, henan provincial public security organization, economic, traffic, public security police, fire, such as launching, in conjunction with the provincial department of quality control, for the 13 municipalities 77 electric bicycle manufacturers, head of the legal representative and centrally questioning.
Henan province public security department related to leadership, strengthen the electric fire safety source control put forward specific requirements, is one of the enterprises need to organize enterprise technical experts special diagnosis and optimization technology, in the body use noncombustible or flame retardant material, set up the battery leakage, overload protection device, to improve electric bicycle essence security.
However, faced with fierce competition in the industry environment, electric vehicle manufacturing enterprises using halogen-free flame retardant materials is not reality, suggest appropriate limits the use of electric cars plastic body parts, improve the combustion performance of the electric car itself level, inside the electrical failure prone body around, more use of halogen free flame retardant materials, ensure even electrical fault happened, also won't cause fire in the electric vehicle.
"Gain and loss of halogen free flame retardant PP"