Evaluation and testing of safety standards for automotive interior materials

 

　　 1. Safety performance evaluation index of automotive interior materials

 

　　 The existing safety performance evaluation indicators of automotive interior materials mainly include atomization value, flame retardancy, odor, formaldehyde content, and volatile compound emissions. As there are no applicable standards for the control of environmental pollutants in vehicles in China, some companies have not paid enough attention to environmental pollution in vehicles and have not taken corresponding measures. Pollutants that lack standard limits, such as polycyclic aromatic hydrocarbons and other carcinogens, are likely to cause pollutant "black holes." Therefore, it is necessary to strengthen the supervision and inspection of the environment in the car, increase the monitoring items of the pollutants in the car, and set the limit of the pollutant in the car to objectively reflect the air quality in the car, promote the prevention and control of the environmental pollution in the car, and protect the consumers. Physical and mental health is imminent.

 

　　1.1 Air quality evaluation in the car

 

　　 (1) Sources of air pollutants in the car Pollutants in the car

 

　　 One is the release of harmful substances contained in the main material of the car;

 

　　 The second is the release of harmful substances contained in the interior decoration materials of the car;

 

　　 The third is the entry of external pollutants;

 

　　Four is derived from the living habits of the drivers and passengers in the car.

 

The release of small molecular substances that have not participated in polymerization such as styrene, vinyl acetate, propylene, phenolic and less polymerized molecules among high molecular substances such as plastics, rubber and chemical fibers used in the main body of automobiles; the interior decoration materials themselves and their use All kinds of adhesives will contain pollutants and cause secondary pollution of the air in the car. The pollutants mainly include formaldehyde, benzene, toluene, chloroform, acetone, xylene, olefins, chlorinated hydrocarbons and aromatic hydrocarbons;

 

The main external pollutants are carbon monoxide, hydrocarbons, hydroxides, etc. The pollutants accumulated in the pipes of automobile exhaust and the air-conditioning evaporator in the car will also enter the car after long-term use; drivers and passengers sprayed to improve the smell of new cars Air fresheners, formaldehyde scavengers, car fragrances, etc. are also sources of secondary air pollution in the car. Smoking in the car by drivers and passengers will also increase the level of air pollutants such as volatile harmful substances and dust.

 

　　 (2) The harm of air pollution in the car

 

When a car is driving, the inside of the car is a relatively closed environment. Drivers and passengers will experience headaches, fatigue and other symptoms in a heavily polluted car environment for a long time. In severe cases, they will have dermatitis, asthma, weakened immunity, and even It is leukopenia. Therefore, a complete test standard must be established to evaluate the pollution degree of the car's environment.

 

　　1.2 Flame retardant performance

 

　　 Automotive interior materials must have good flame retardant and flame retardant properties to provide drivers and passengers with a certain amount of survival and escape time. Developed countries have formulated strict regulations for this, such as: US Federal Regulations FMVSS 571.302, International Organization for Standardization ISO 3795 and European Conference Council Directive 95/28/EC all have provisions on the combustion characteristics of automotive interior materials.

 

　　 In 1987, my country also formulated the corresponding mandatory standard GB 8410-1987, which was revised twice in 1994 and 2006 to form GB 8410-2006, which corresponds to FMVSS 571.302. my country's standard GB 8410-2006 has too low requirements for flame retardant performance, which is not enough to effectively prevent and delay the occurrence of fires. Among them, there is only a simple requirement for the flame retardant performance of all automotive interior materials, that is, the horizontal burning speed is not high under the relevant test conditions. More than 100 mm/min. This threshold is so low that most plastics, especially thermoplastics, can meet the requirements almost without any flame retardant treatment. Such interior materials actually become "combustion-supporting materials" when a fire occurs. Therefore, the flame retardant grade, oxygen index and smoke density of automobile interior materials can be considered at the same time.

 

　　Picture: Classification of flame retardants

 

　　1.3 Atomization performance

 

　　 Atomization performance is an important indicator of automotive interior materials. Automotive interior materials such as leather, plastics, textiles, and adhesives for bonding materials all contain some volatile substances, which will volatilize under certain conditions and condense on the car windows or windshield, seriously affecting the driver’s sight and Driving safety. At present, there is no unified requirement for atomization performance in China. Some domestic and foreign automobile standardization organizations and automobile brand manufacturers generally require the atomization value of automotive interior leather to be ≤2mg～5mg.

 

　　1.4 Other indicators

 

　　1.4.1 polycyclic aromatic hydrocarbons

 

In recent years, the media has repeatedly reported that many domestic cars have been detected with strong carcinogenic polycyclic aromatic hydrocarbons (PAHs). Due to the harm of PAHs, many countries and regions have imposed restrictions on them, such as: EU Directive 2005/69/EC ( The 27th revision of Directive 76/769/EEC) requires that the content of benzo (a) pyrene (BaP) in the added oil and tires is less than 1 mg/kg or the total content of 8 polycyclic aromatic hydrocarbons (PAHs) is less than 10 mg/ kg, the U.S. Environmental Agency requires that the 16 PAHs for priority evaluation should not be contained. The German GS certification standard ZEK 01.4-08 requires the BaP limit to be 1 mg/kg or the total content limit of 18 PAHs to 10 mg/kg (the second category material). Domestic national standards that have limited air quality in cars, such as GB/T 27630-2011 "Guidelines for Air Quality Evaluation in Passenger Cars" and GB/T17729-2009 "Requirements for Air Quality in Long-distance Passenger Cars", but do not cover this carcinogenicity Things. Therefore, the content of polycyclic aromatic hydrocarbons is also necessary as an index for the safety evaluation of automotive interior decoration materials.

 

　　1.4.2 Banned flame retardants

 

　　 At present, the proportion of my country's automobile plastic parts in the total automobile share has reached about 10%, especially automobile plastic interior parts generally require flame retardancy. Flame retardancy is the most important safety feature of automotive interior materials. The use of flame retardants for finishing can impart certain flame retardancy [3], and some of the currently used flame retardants are inherently toxic or produce toxic substances when burned. Some flame retardants are bioaccumulative and carcinogenic. Therefore, the limit of such flame retardants should also become one of the indicators for evaluating the safety performance of automotive interior materials. In addition, some conventional indicators such as azo dyes, extractable heavy metals, pentachlorophenol, etc. should also be included in the safety evaluation of automotive interior decoration materials. The determination can be carried out in accordance with the national standard testing method of the corresponding material.

For more information, please visit:
https://www.qinsun-lab.com/index.html