Secretary General of the Technical Committee of Facilities and Equipment of the National Sports Standardization Technical Committee
Director of Beijing Huaan Joint Certification Testing Center
Liu Haipeng
Recently, Jiangsu, Shanghai, Shaanxi, and Xinjiang have successively exploded plastic trackes that are toxic and have odors, especially in primary and secondary schools, causing students to have nosebleeds, school suspensions, and even the dismantling of new plastic trackes, causing the whole society. attention. As a sports person, I also hate the runway material producers and contractors who have lost their conscience. They use low-quality raw materials to produce low-priced and inferior products to fill the market and make profits. This industry is also at a time when it is necessary to control the power. Otherwise, there will be endless troubles.
As the infrastructure of track and field sports, plastic track is widely used in the world and is also an indispensable part of improving the level of teaching facilities in schools. I remember that in 2004, there were media reports in Taiwan, Jiangsu and Beijing that the plastic track was poisonous. Today, the society is still controversial, and some places have to restore the original cinder track or the dirt track. Many of the controversies caused by this phenomenon are those who focus on non-sports facilities, and the professional team that is really engaged in the management and construction of sports facilities has not yet published a clear viewpoint.
The National Sports Standardization Technical Committee Facilities and Equipment Subcommittee is the professional technical organization that manages the national sports facilities standards. As the Secretary General of the Technical Committee, I think we should use a scientific perspective to correctly treat the plastic track as a toxic viewpoint and phenomenon. Use professional knowledge to answer how to build a qualified non-toxic plastic track. The following is explained from several aspects.
First, what is the plastic track
The plastic track is divided into polyurethane (composite, hybrid, water-permeable), prefabricated rubber coils and water-based plastic. Polyurethanes are the most traditional materials in the market, and they are also the protagonists of the poisonous runway that has recently been hyped.
Polyurethane, collectively known as polyurethane, is a general term for macromolecular compounds containing repeating carbamate groups in the backbone. Polyurethane (PU) is a polymer made of a polyisocyanate and a polyether polyol or a polyester polyol or a small molecular polyol, a polyamine or a chain extender such as water or a crosslinking agent. Polyurethane is widely used in many fields such as automobile manufacturing, refrigerator manufacturing, transportation, civil engineering, footwear, synthetic leather, fabric, electromechanical, petrochemical, mining machinery, aviation, medical, agriculture, and so on. Polyurethane has excellent biocompatibility and is also widely used as a biomedical material, such as artificial heart pacemakers, artificial blood vessels, artificial bones, artificial esophagus, artificial kidneys, artificial dialysis membranes, and the like. Polyurethane products Plastic track is a small category of polyurethane applications.
Second, the standards for the implementation of polyurethane plastic track
At present, the standards related to plastic track products implemented in China are sports standards and environmental protection standards.
1, sports standards
National Standard GB/T 22517.6-2011 "Sports Field Requirements and Test Methods Part 1: Track and Field Sites", GB/T 14833-2011 "Synthetic Material Runway Surface Layer"
Both standards stipulate the limits of toxic and hazardous substances in plastic runway products. These toxic and hazardous substances include benzene, toluene + xylene, free toluene diisocyanate (TDI), lead, cadmium, chromium and mercury. It also specifies physical properties such as impact absorption, slip resistance, tensile properties, and the like.
The limit of toxic and hazardous substances is:
Serial number
project
content
1
Benzene / (mg / kg) ≤
50
2
Total toluene and xylene / (mg / kg) ≤
50
3
Free toluene dimethocyanate / (mg / kg) ≤
200
4
Heavy metal / (mg / kg) ≤
Lead Pb
90
Cadmium Cd
10
Chromium Cr
10
Mercury Hg
2
Physical properties are:
Surface type
Tensile Strength
MPa
Elongation at break
%
Shock absorption
%
Vertical deformation
Mm
Anti-slip value
BPN20°C
Flame retardancy
(level)
Non-permeable synthetic surface material
≥0.50
≥40
35~50
0.6~2.2
≥47
1
Water-permeable synthetic surface material
≥0.40
≥40
35~50
0.6~2.2
≥47
1
2, environmental performance standards
GB 18583-2008 "Limits of Hazardous Substances in Interior Decoration Materials Adhesives", JC 1066-2008 "Limits of Hazardous Substances in Building Waterproof Coatings", HJ 457-2009 "Technical Requirements for Environmental Labeling Products, Waterproof Coatings".
National Standard GB 18583-2008 "Limits of Hazardous Substances in Interior Decoration Materials Adhesives" is the standard adopted by most domestic manufacturers, and also stipulates the limit of harmful substances:
Limits of harmful substances in solvent-based adhesives
project
index
Neoprene adhesive
SBS adhesive
Polyurethane adhesive
Other adhesive
Free formaldehyde / (g / kg)
≤0.50
-
-
Benzene / (g / kg)
≤0.50
Toluene + xylene / (g / kg)
≤200
≤150
≤150
≤150
Toluene and isocyanate / (g / kg)
-
≤10
-
Dichloromethane / (g / kg)
Total ≤5.0
≤50
-
≤50
1,2 dichloroethane / (g / kg)
Total ≤5.0
1,1,2 trichloroethane / (g / kg)
Trichloroethylene / (g / kg)
Total Volatile Organic Compounds / (g / L)
≤700
≤650
≤700
≤700
Note: If the product specifies the dilution ratio or the product has a two-component or multi-component composition, the content of the diluent and each component should be determined separately, and then the total amount after mixing should be calculated according to the ratio specified by the product. If the amount of diluent used is within a certain range, it should be calculated according to the recommended maximum dilution.
Limits of harmful substances in water-based adhesives
project
index
Formaldehyde adhesive
Polyvinyl acetate adhesive
Rubber adhesive
Polyurethane adhesive
Other adhesive
Free formaldehyde / (g / kg)
≤1.0
≤1.0
≤1.0
-
≤1.0
Benzene / (g / kg)
≤2.0
Toluene + xylene / (g / kg)
≤10
Total Volatile Organic Compounds / (g / L)
≤350
≤110
≤250
≤100
≤350
Limits of harmful substances in bulk adhesives
project
index
Total Volatile Organic Compounds / (g / L)
≤100
Building Materials Industry Standard JC 1066-2008 "Restriction of Hazardous Substances in Building Waterproof Coatings" is divided into two grades A and B according to the content of harmful substances in building waterproof coatings. According to the nature, it is divided into water-based, reactive and solvent-based. The requirements for hazardous substances are as follows:
Waterproof coating classification example
classification
Product example
Waterborne
Water-based asphalt-based waterproof coating, water-based silicone waterproofing agent, water-based waterproofing agent, polymer cement waterproof coating, polymer emulsion waterproof coating (including acrylic acid, ethylene vinyl acetate, etc.), water-based silicone rubber waterproof coating, polymer cement Waterproof mortar, etc.
Reactive type
Polyurethane waterproof coating (including one-component, water-curing, two-component, etc.), polyurea waterproof coating, epoxy resin modified waterproof coating, reactive polymer cement waterproof coating, etc.
Solvent type
Solvent-based asphalt-based waterproof coating, solvent-based waterproofing agent, solvent-based base treatment agent, etc.
Building waterproof coatings
Waterborne building waterproof coating
Serial number
project
content
A
B
1
Volatile Organic Compound (VOC) content / (g / L) ≤
80
120
2
Free formaldehyde / (mg / kg) ≤
100
200
3
Benzene, toluene, ethylbenzene and xylene total / (mg / kg) ≤
300
4
Ammonia / (mg / kg) ≤
500
1000
5
Soluble heavy metal a) / (mg / kg) ≤
Lead Pb
90
Cadmium Cd
75
Chromium Cr
60
Mercury Hg
60
a) Colorless, white, black waterproof coatings do not require the determination of soluble heavy metals.
Reactive building waterproof coating
Serial number
project
content
A
B
1
Volatile Organic Compound (VOC) content / (g / L) ≤
50
200
2
Benzene / (mg / kg) ≤
200
3
Toluene + ethylbenzene + xylene / (g / kg) ≤
1.0
5.0
4
Phenol / (mg / kg) ≤
200
500
5
蒽/(mg/kg) ≤
10
100
6
Naphthalene / (mg / kg) ≤
200
500
7
Free TDIa) / (g / kg) ≤
3
7
8
Soluble heavy metal b) / (mg / kg) ≤
Lead Pb
90
Cadmium Cd
75
Chromium Cr
60
Mercury Hg
60
a) Only suitable for polyurethane waterproof coatings.
b) Colorless, white, black waterproof coatings do not require the determination of soluble heavy metals.
Solvent-based building waterproof coating
Serial number
project
content
B
1
Volatile Organic Compound (VOC) content / (g / L) ≤
750
2
Benzene / (g / kg) ≤
2.0
3
Toluene + ethylbenzene + xylene / (g / kg) ≤
400
4
Phenol / (mg / kg) ≤
500
5
蒽/(mg/kg) ≤
100
6
Naphthalene / (mg / kg) ≤
500
7
Soluble heavy metal a) / (mg / kg) ≤
Lead Pb
90
Cadmium Cd
75
Chromium Cr
60
Mercury Hg
60
a) Colorless, white, black waterproof coatings do not require the determination of soluble heavy metals.
Environmental protection industry standard HJ 457-2009 "Environmental Marking Product Technical Requirements Waterproof Coating" applies to volatile curing waterproof coating (two-component polymer cement waterproof coating, one-component acrylate polymer emulsion waterproof coating) and reaction curing waterproofing Coatings (polyurethane waterproof coating, modified epoxy waterproof coating, polyurea waterproof coating). There are also corresponding regulations on the limit of harmful substances:
Limits of harmful substances in volatile curing waterproof coatings
project
Two-component polymer cement waterproof coating
One-component acrylate polymerization
Compound emulsion waterproof coating
Liquid material
Powder
VOC/(g/L)
≤10
-
≤10
Internal exposure index
-
≤0.6
-
External exposure index
≤0.6
-
Soluble lead (Pb) / (mg / kg)
Soluble cadmium (Cd) / (mg / kg)
Soluble chromium (Cr) / (mg / kg)
Soluble mercury (Hg) / (mg / kg)
≤90
≤75
≤60
≤60
-
≤90
≤75
≤60
≤60
Formaldehyde / (mg / kg)
≤100
-
≤100
Limits of harmful substances in reaction-curing waterproof coatings
project
Epoxy waterproof coating
Polyurea waterproof coating
Polyurethane waterproof coating
Single component
Two component
VOC/(g/kg)
≤150
≤50
≤100
Benzene / (g / kg)
≤0.5
Benzene solvent / (g / kg)
≤80
≤50
≤80
Soluble lead (Pb) / (mg / kg)
Soluble cadmium (Cd) / (mg / kg)
Soluble chromium (Cr) / (mg / kg)
Soluble mercury (Hg) / (mg / kg)
≤90
≤75
≤60
≤60
Free toluene diisocyanate (TDI)/% in curing agent
-
≤0.5
-
≤0.5
Among the above standards, GB/T 22517.6-2011 and GB/T 14833-2011 are consistent with the requirements for hazardous substances. In other standards, the requirements for soluble heavy metal content are basically the same, but the types and limits of other harmful substances, especially hydrocarbon organic substances, are different due to different production and construction processes. Each manufacturer can choose different standards based on its own conditions and product types, and make explicit statements in the company's technical documents and sales documents.
It is recommended that in the raw material stage of plastic products, some requirements for stricter requirements for hazardous substances in GB 18583-2008 and JC 1066-2008 can be implemented, and the hazardous substances content of plastic sites after construction is completed. GB/T 22517.6-2011 And GB/T 14833-2011.
However, there is currently no relevant national standard for the impact of air quality on plastic track pavement and the quality of air over the runway.
Third, the source of toxic odor and scientific production and paving
The smell of plastic track is mainly derived from the possible occurrence of chloride in polyurethane (PU) glue, residual free diisocyanate (TDI), residual of some solvents (toluene, xylene, etc.), residual organic lead, residual in EPDM colored particles. Sulfide, residual sulfide in black particles, polycyclic aromatic hydrocarbons, bromobenzene additives, and the like. Compounds that may cause harm to the human body or the environment are mainly chlorides in polyurethane (PU) glue, free toluene diisocyanate (TDI), benzene compounds, sulfides in rubber, various compounds in polycyclic aromatic hydrocarbons, particles and Heavy metals in glue, once exceeded, can cause dizziness, vomiting, fainting, cancer, mutual difficulty, and can cause fatal damage to humans, animals, plants and the environment.
It should be specially pointed out that the excessive use of ortho-benzene plasticizers will lead to the sterilization of boys. The strict regulations on ortho-benzene plasticizers are related to the laws and regulations of Europe and the United States, of which the EU was in December 1999. A resolution (1999/815/EC) was formally adopted on the 7th and a temporary injunction was passed. The ban does not limit all PVC toys, and only six plasticizers (DEHP, DBP, BBP, DNOP, DINP, DIDP) in mouth-to-mouth PVC plastic products for children under three years of age are restricted. Although the EU's scope for phthalate plasticizers is gradually expanding, from the initial three-year-old children's contact with PVC materials, to all children's toys, food contact products, and even current electronic products and medical supplies. The definition has also entered a transitional period, but it is known from the process that the limited use of phthalate plasticizers in the EU is based on the premise that it can be imported and directly in contact with the human body, while the phthalic plasticizers are The volatility is low. For the plastic runway as a public sports infrastructure, there is no possibility of entry and long-term contact with the human body. From the overall perspective, phthalate plasticizers are harmful to humans and nature, but the use of ortho-benzene plasticizers used in plastic runways can lead to the sterilization of children using plastic track. There is no scientific data. suspicious.
At present, the plastic material manufacturers and engineering companies in the Chinese market are mixed. Some incompetent and non-professional people use recycled polystyrene, industrial poison paraffin, drier and other waste materials in order to maximize their profits. In order to reduce the difficulty, a large amount of thinner (such as toluene, xylene and other heavy, toxic diluents, Tianna water, gasoline), cheap inorganic fillers, and ultimately reduce the cost of plastic materials, conscience to make some toxicity Large and polluting non-standard products. This kind of product will not only cause strong irritation and harm to the construction workers during the paving process. After the paving is completed, it will not be volatilized within 5 years, and there will always be a taste of thinner, especially in hot weather or strong ultraviolet radiation. It will accelerate the release of odorous gas, which will always poison the campus and the atmosphere. Such a site is not only environmentally friendly, but also has physical properties that are not up to standard. It often occurs such as thin thickness, too hard surface, and delamination of the foundation. phenomenon. Eventually, the children of the school and the athletes in the sports field were victimized to varying degrees.
If the formula is scientific and the chemical monomers in the excellent environmentally friendly plastic track are fully reacted, the residue of the above compounds will be very little or not, except that the strength is higher and the elasticity is better, because the reaction is complete, even in the high temperature environment, there is no taste. . However, if the formula is not scientific, the reaction will be incomplete, and there will be residue, which is the source of toxic odor.
4. Reasons for the incident of poisonous runway and suggestions for settlement
The reasons for the poisoning of the plastic runway involve all aspects, such as the investor, the owner, the supervisor, the manufacturer and the engineering company, which are related to the cost, project management, and completion acceptance. The reason for investigating the manufacturer or the construction unit alone is also Irresponsible performance.
At present, when bidding for the purchase of sports facilities in the society, the owners, investors, and bidding units do not respect the economic laws, blindly reduce the bidding procurement price, and the manufacturers and engineering companies viciously compete in the bidding stage. The original unit price of 200 yuan or more, the transaction price is actually low. To 100 yuan or even 60 yuan. Low-cost purchases of low-price bids, coupled with non-professional construction, caused the runway to be toxic.
In order to build a qualified non-toxic plastic track, all parties concerned should follow the laws of the market economy, understand and learn the relevant standards in detail, consult the recommendations of professional organizations, and strictly control the procurement, construction, establishment, completion, acceptance and other stages. suggestions below:
1. One point for one price, set a reasonable purchase price
The procurement organization is unclear about the true cost of the qualified plastic runway, and has not been able to understand and consult in depth. When the bidding documents are formulated, the lowest bid is stipulated, resulting in vicious competition.
In the past year, nearly 3,000 raw material production suppliers have been added nationwide. These small workshops account for 50% or more of the original production raw material market in one year. There is no qualification, no technology, no production management system. There is no quality assurance system, no safety production management measures, no product inspection and testing methods, no professional production personnel and technical personnel, etc., and the manufacturing cost is very low;
Some manufacturers use toxic and harmless low-quality inferior raw materials to produce products, add toluene, xylene, acetone and inferior thinners containing excessive heavy metals, catalysts, solvents, etc. in plastic raw materials. What is more serious is that some manufacturers use aromatic hydrocarbons. Chemicals that use chemical masking methods to mask odors and make these materials even more terrifying;
China's plastic raw material manufacturers with a certain scale basically have their own complete management system and certification system, and have certain research and development capabilities and testing methods. These units have played a certain role in the construction of China's sports fields in the past, and have also achieved great glory. Performance; today these units face the dilemma of being replaced by numerous small workshops;
The market price of domestically-qualified paved hybrid and composite plastic track is generally around 200 yuan, the price of high-quality products is about 250 yuan or even higher, and the market price of water-permeable plastic track is generally around 150 yuan. The market price of prefabricated rubber track materials is generally not lower than 380 yuan or even higher. Quotations below this price can basically be judged to be impossible.
2, multi-faceted understanding, consulting professional and technical institutions, procurement of environmentally friendly materials
In the early stage of preparation, the procurement related parties should study the requirements of various standards for product performance and raw material performance in detail, and formulate scientific technical requirements. In some places, the purchaser or the owner may do this once in a lifetime, and there is no more experience or time to study the relevant standards and technologies. It is even more impossible to understand the current situation of the sports facilities industry. Then you can hire or Consult a sports department or a professional sports facility technical agency to provide technical check-in services.
The traditional plastic track is a polyurethane material, which is used in the production and paving process. The requirement for a limited amount of toxic and hazardous substances is crucial. During the construction process, the construction company should ask the manufacturer's material ratio and construction process conditions no matter which material is obtained. If the weather temperature is low or the material reacts quickly when the material is stirred, etc., the material will be added with thinner. You must contact the manufacturer to inquire about the type, specification and model to be added. Do not add other chemical additives and solids without authorization. Raw materials; some manufacturers use toluene, as well as xylene, gasoline, etc., the use of these materials must be degree, excessive use will inevitably lead to the volatility of toxic and hazardous substances. It is best to use a solvent that is low in toxicity, fast in volatilization, and does not remain for a long period of time, such as ethyl acetate solvent, which has no taste during construction, and does not smell any odor or pungent taste after the completion of construction. Of course, it is better to use a solvent that is more environmentally friendly than ethyl ester.
With the advancement of technology, there have also emerged more environmentally-friendly prefabricated rubber track materials and water-based plastic track glue materials. No chemical or organic substances are added in production or construction, which greatly reduces the limit of toxic and harmful substances in the runway.
3. Purchasing products of competent enterprises with capabilities
Adjust the bidding mechanism, improve the seriousness and impartiality of the testing institutions and certification bodies, and prevent the inferior products from entering the market. At present, the construction of plastic track construction in many places is unorganized, the quality of the construction team is low, the lack of professional knowledge of the sports ground, and the lack of professional management technicians in the construction unit, the most chaotic situation in the history of plastic track construction;
In the past year, nearly 3,000 raw material production suppliers have been added nationwide. These small workshops account for 50% or more of the original production raw material market in one year. There is no qualification, no technology, no production management system. There is no quality assurance system, no safety production management measures, no product inspection and testing methods, no professional production personnel and technical personnel, etc., and the manufacturing cost is very low;
Some manufacturers use toxic and harmless low-quality inferior raw materials to produce products, add toluene, xylene, acetone and inferior thinners containing excessive heavy metals, catalysts, solvents, etc. in plastic raw materials. What is more serious is that some manufacturers use aromatic hydrocarbons. Chemicals that use chemical masking methods to mask odors and make these materials even more terrifying;
China's plastic raw material manufacturers with a certain scale basically have their own complete management system and certification system, and have certain research and development capabilities and testing methods. These units have played a certain role in the construction of China's sports fields in the past, and have also achieved great glory. Performance; today these units face the dilemma of being replaced by numerous small workshops;
Most of the problems that have arisen are caused by enterprises that have no professional ability and more production and construction performance of sports facilities; or they are subcontracted to some contractors or individuals after being squeezed out of profits; Chemical, caused by material manufacturers and construction units at very low prices; construction companies directly purchase raw materials back or self-pave.
Therefore, in the early stage of procurement, we must do a good job in research, and carry out detailed investigations on the production capacity, product quality management capabilities, engineering management capabilities, and past performance of manufacturers or construction companies. Manufacturers, select companies with more performance to participate in the bidding. In the tendering phase, the physical and chemical performance test report of each material product and the manufacturer's authorization certificate should be verified.
Raw materials should choose good quality rubber particles. Often the problem of the plastic field is also the reason for the inferior black rubber particles. Once the inferior black rubber particles are combined with the adhesive, a chemical reaction will occur, which will cause the plastic site to be black, oily and sticky; EPDM rubber particles should be selected to contain the original rubber. Products with higher volume and lower oil content generally contain no less than 13% of raw rubber; before construction, they should ask the manufacturer for product certification, product inspection report and product instruction manual to ensure the purchase of the materials. quality;
4. Construction site supervision and strict management
The construction party and the supervisory party must have a sense of responsibility and supervision should be in place. Many builders and supervisors are the first to contact this material and have no idea how to control it. Just like the decoration materials in the building, it is not uncontrollable, but it does not know how to control or not control at all. Currently, bid samples generally require physical performance to meet the standards, but environmental indicators must also be required to meet the standards. Finally, taking the sample and the on-site product for comparison, the performance can not be compared, take the sample and the product to compare it.
The construction of the stadium is a very professional construction project. From the site selection to the completion of the project, it contains very professional construction technology and construction technology. The construction technology of the infrastructure is completely different from the general construction engineering and municipal engineering. The construction technology of the stadium ground floor must be reflected in advance. Many construction teams in the surface construction have not been professionally trained, especially plastics. In order to win the paving business, the construction team will not hesitate to adopt the ultra-low quotation method and purchase ultra-low-priced inferior raw materials to mix and match; many winning bidders cannot implement the construction project at the low price bid, but the project will be transferred again. The package is for the leisurely staff in the society, earning part of the profit, which is far lower than the cost price project. It seems that it is impossible to complete the sports ground. The construction team has been transformed into a successful construction, and the micro-small Raw material production workshops and some profit-making raw material manufacturers have extended their “helpers†to create a supply market for toxic and harmful materials and inferior products at ultra-low prices.
The raw materials supplied from these raw materials suppliers themselves have poisonous and harmful raw materials. When the construction team is working, the raw materials are re-distributed, and the filling materials and inferior chemical thinners or solvents are indefinitely incorporated, and the toxic and harmful materials are like this. Enter the construction site.
Engineering supervision is an important part of ensuring the quality of the site. However, there is no professional sports facility engineering supervision unit in China. Many supervisory engineers are ignorant of this. They lack basic knowledge and relevant professional knowledge of the sports ground, and basically rely entirely on the construction team and supervision. It is also a passing, causing supervision. As the final user, the owner should assume more responsibility for supervision. It is recommended that after the raw materials arrive, the sampling and chemical performance should be carried out. After the samples are tested, the construction is carried out. Although this will delay a certain period of time, from the perspective of ensuring the health of the human body and the environment, it is worthwhile to delay a little time.
5, completion acceptance
Most of the current completion acceptances have gone through the battlefield. Many sports venues have not passed the professional inspection and inspection of the authoritative institutions. Many construction unit leaders walked on the site to see if the acceptance was passed, and the local so-called experts were invited to accept the test. Its professionalism is far less than that of an authoritative organization; even if it is sent to a professional laboratory for testing, many samples of products submitted for inspection do not really represent the actual situation at the construction site.
During the construction of the site, the construction unit should be required to use the same raw materials to produce the same samples as the plastic track at the same time, or to take samples at the completion site, and then send the samples to a qualified professional testing agency for physical and chemical performance testing. When the test results prove that they are qualified, the project settlement can be carried out.
V. Conclusion
In short, to optimize the teaching and competition environment, the construction of the plastic runway itself is correct, as long as the purchaser, construction, production, construction, supervision, testing and other aspects related to the runway at the same time do the due diligence, inferior materials There is no market for construction and construction, and there will be no poisonous students and plastic runways that pollute the atmosphere. As long as there are people and enterprises with conscience, and for the health of future generations and the development of sports in China, they will do good for the society, and there will be sports venues that are good for their loved ones.
Guangzhou China Han Oral Products Co., Ltd. , https://www.gzchinahan.com