Crumb rubber is the recycled rubber produced from automotive and truck tires. During the recycling process, steel ropes and tires (feathers) are released, leaving rubber tires with granular consistency. Advanced process with a granulator or cracker factory, perhaps with the help of cryogenics or by mechanical means, reduces the particle size further. The particles are sized and classified according to various criteria including color (only black or black and white). These granules are sized by passing through the screen, size by dimension (1/4 inch) or mesh (holes per inch: 10, 20, etc.). Crumb rubber is often used in synthetic grass as a cushion.
Video Crumb rubber
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The first synthetic grass was placed on top of the concrete in 1964 and is known as "Chem Grass". It was later named "Astro Turf" when it was installed at the Houston Astrodome in 1966. Athletes do not like to play in this field because it is dangerous and uncomfortable for their landing. Compared to only a thin layer of Astro Turf on concrete, a new artificial turf was developed in early 2000 and called styrene butadiene rubber, best known as "crumb rubber." This rubber is made from small pieces of black crumbs that come from used tires. Tire crumbs poured among fake grass, giving more artificial ground pillows and support. This is a better solution and a satisfied athlete and assisted in the prevention of major injuries.
Maps Crumb rubber
Recycled pavement material
Asphalt rubber is the largest market for crumb rubber in the United States, spending about 220 million pounds (100 kilo liters), or about 12 million tires per year. Crumb rubber is also used as a ground cover under play equipment, and as a surface material for running tracks and athletic fields.
Composition
- 71% recoverable rubber
- steel 14%
- 3% fiber
- 12% foreign matter
Grading
The following is a general classification of crumb rubber:
Retreaders tire buffings should consist of clean, fresh, dry buffings from tire retreading preparation operations.
No.1 - Granule Ban consists of tire crumbs, Black Only Guaranteed MetalFree, sized. Magnetically separated material is not acceptable. Fluff of the tire strap removed.
No.2 - Granule Ban consists of tire crumbs, Black & amp; White Guaranteed MetalFree, measuring minus 40 Mesh. Magnetically separated material is not acceptable. Fluff of the tire strap removed.
No.3 - Granule Tires should consist of sand tire crumbs, Black Only Magnetically Separated, sized. Fluff of the tire strap removed.
No.4 - Granule Ban consists of tire crumbs, Black & amp; White Magnetically Separated, sized. Fluff of the tire strap removed.
No.5 - Tire Granules must consist of unbranded tire crumbs, Sized, Inseparable, not magnetically separated, the feathers of the tire cord are not removed.
Destination
- Surfaces and athletic fields (rubber mulch)
- Agrimat and horse riding
- Automotive spare parts and tires
- Construction/indoor
- Landscapes, paths, and paths
- Products printed and extruded
- Surfing surfaces and other security surfaces
- Rubber modifies asphalt and sealant
- Mixture of rubber and plastic
Benefits
When confronted with asphalt overlays, reflection cracks can arise and cause unwanted cracking patterns under the sidewalk. Asphalt rubber modification uses a voltage absorbent membrane that reduces the reflective crack due to its elastic properties. With fewer cracks, there are fewer improvements, so crumb rubber helps reduce maintenance costs. The sidewalks have an increased lifetime because after several different use and exposure elements, the ordinary asphalt loses elasticity over time. The use of artificial rubber refers to the formation of cracks and has anti-aging effects that keep the asphalt in better condition.
Developing Concerns
Scientific Research
Crumb rubber infill has become a much-studied topic. To date, there are nearly 100 studies and reports, from government agencies and independent researchers, who have assessed the potential health risks based on multiple exposure paths. The Connecticut Department of Public Health conducted extensive research and published three peer-reviewed studies on the safety of crumb rubber and determined that there was "no scientific support to find an increased cancer risk from inhalation or ingest of chemicals derived from recycled tires used in the field synthetic grass. "The Massachusetts Department of Health also studied crumb rubber and came to similar conclusions. Three federal agencies are currently conducting research as well. However and more recently: The US Environmental Protection Agency (EPA) will complete a study led by colleagues from all US studies in mid to late 2018, using peer and public evidence to fill the information gap between study roads and real-life anecdotal worries, experience with a medical scientific perspective is included. In the European Union, the European Chemical Agency (ECHA) has also produced a report entitled APPENDIX XV that specifically looks at the chemical composition of crumb rubber and concerns. It also concludes overall that the risks are very low compared to health and sports benefits. However, recently in 2017 and now in 2018, further chemicals have begun to be further investigated that were not previously listed in the ANNEX report incarnate on rubber crumbs. Highly Concerned Substances (SVHC's) are carcinogenic chemicals, endocrine disruptive chemicals and chemicals that are harmful to aquatic life and increasingly identified as a need for restrictions in the ECHA REACH2018 program. Chemicals such as chrysene, benzo (a) pyrene, benzo (e) pyrene, benzene and others are now on the list of prohibited chemicals candidates, ready to be included in the next incarnation of the APPENDIX XIV report, possibly also by 2018. ECHA limits list of Chemical Candidates, click here. With PAHs, phthalates, lead and all other substances already mentioned so far in this whole topic, it is worth mentioning that no research has examined the cocktail effect of various chemicals or substances of concern and by 2018, the US. professional women's soccer goalkeepers who in recent years trained the younger goalkeeper, seeing an increase in the number of teenagers with cancer. Ami Griffin's discovery has been recorded by him for several years. The discovery may be anecdotal but fixed, do point at the relationship between young players who have been playing on surfaces that have rubber crumbs as infill and with them developing cancer. To view the study, click here.
Athletics
A field of synthetic turf is found throughout the United States and is most commonly found in high school and athletic facilities. Rubber crumbs are used in "infill" in artificial turf systems to make the surface safe. The volume of research and testing from academia, federal and state governments including New York, California, Massachusetts and Connecticut, and the school system has examined all the questionable questions about synthetic turf. Many of these studies conclude that there is no health risk. Conflicting studies have found that raw material sources (automotive tires) contain high levels of polycyclic aromatic hydrocarbons and metals such as zinc that have been shown to affect skin health, acute, and long-term. The EPA is (in autumn 2015) investigating health affecting crumb rubber exposure and preliminary results from this study are expected in early 2016.
State of Connecticut - Department of Public Health: "Based on these findings, the use of indoor and outdoor grass fields is not associated with increased health risks, but it would be wise for building operators to provide adequate ventilation to prevent accumulation of volatile organic compounds (VOC ) and semi-volatile organic compounds (SVOC) bonded to rubber in the indoor field.The current study did not evaluate new fields under hot weather conditions so the potential for acute risks in these circumstances was another uncertainty.The results were generally consistent with findings from the study conducted by New York City, New York State, USEPA and Norway that tested various types of fields and under various weather conditions, so it appears that the current results adequately represent the conditions that can be found in indoor and outdoor crumb rubber fields, although This provisional conclusion can benefit from pen gujian additional fields.. "
Brian T. Pavilonis, Clifford P. Weisel, Brian Buckley, and Paul J. Lioy: "This study shows that for the products and fields we tested, infill and synthetic grass exposure is generally considered de minimus [sic] ], with possible exceptions leading to multiple fields and materials. "
Chief Medical Officer of FIFA Prof Ji? ÃÆ' Dvo? ÃÆ'¡k says that "Most researches have been on higher surface area particles and have concluded they are currently acceptable. Therefore larger granules used in synthetic grass will have less potential for emissions For example, a study conducted by the Danish Ministry of the Environment concluded that the health risks in children's playgrounds containing used tires and granule rubber were not significant.The available research bodies did not prove the assumption that the cancer caused by exposure to styrene-butadiene (SBR) granulates infill in the grass synthetic can potentially occur. "
Service of Scientific Instruments, Volatile Organic Emissions from Car Tires, 1999, Santford V. Overton & amp; John J. Manura: Ban "Brand A is found to contain many straight and branched chain hydrocarbons, aldehydes, alcohols, ketones, furans and benzene derivatives." The brand tire B... "was found to contain high concentrations of sulfur dioxide (DOT), 2-methyl-1-propene, 2-propanone, 2-methyl-2-pentene, 2,4-pentanedione, acetic and 2, 4- (1H, 3H) pyrimidinedione. "The chemicals extracted from the raw tire in this study will be found in crumb rubber, which is made by grinding raw material tires. The chemicals listed above include carcinogens, and other chemicals with adverse skin and endocrine effects.
Environmental impact
Crumb rubber is used as a synthetic grass filler. In 2007, use in this capacity prevented about 300 million pounds of rubber from polluted landfills. Generally, it takes 20,000-40,000 used tires to produce enough filling to cover the average soccer field (City of Portland, 2008)
The Connecticut Department of Environmental Protection found in a 2010 study that stormwater passes through regular rubber crumbs over acute toxicity of water for zinc. In addition, copper, barium, manganese and aluminum are found at higher levels after the rain water contact material. Semi-volatile organic compounds and PAH were also found to increase. The level of most of these compounds is higher than the background but is below the level set in the drains for environmental protection.
References
Source of the article : Wikipedia
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