Published on Jan 10, 2017
Artificial turf is a surface of synthetic fibers made to look like natural grass. It is most often used in arenas for sports that were originally or are normally played on grass. However, it is now being used on residential lawns and commercial applications as well. The main reason is maintenance—artificial turf stands up to heavy use, such as in sports, and requires no irrigation or trimming.
Domed, covered, and partially covered stadiums may require artificial turf because of the difficulty of getting grass enough sunlight to stay healthy. But artificial turf does have its downside: limited life, periodic cleaning requirements, petroleum use, toxic chemicals from infill, and heightened health and safety concerns.
Artificial turf is a surfacing material used to imitate grass. It is generally used in areas where grass cannot grow, or in areas where grass maintenance is impossible or undesired. Artificial turf is used mainly in sports stadiums and arenas, but can also be found on playgrounds and in other spaces.
Artificial turf has been manufactured since the early 1960s, and was originally produced by Chemstrand Company (later renamed Monsanto Textiles Company). It is produced using manufacturing processes similar to those used in the carpet industry. Since the 1960s, the product has been improved through new designs and better materials. The newest synthetic turf products have been chemically treated to be resistant to ultraviolet rays, and the materials have been improved to be more wear-resistant, less abrasive, and, for some applications, more similar to natural grass.
Artificial turf was first installed in 1964 on a prep school recreation area in Rhode Island.The material came to public prominence in 1966, when AstroTurf was installed in the Astrodome in Houston, Texas. The state-of-the-art indoor stadium had attempted to use natural grass during its initial season in 1965, but this failed miserably and the field conditions were grossly inadequate during the second half of the season, with the dead grass painted green. Due to a limited supply of the new artificial grass, only the infield was installed before the Houston Astros' home opener in April 1966, the outfield was installed in early summer during an extended Astros road trip and first used after the All-Star Break in July.
The use of AstroTurf and similar surfaces became widespread in the U.S. and Canada in the early 1970s, installed in both indoor and outdoor stadiums used for baseball and football. More than 11,000 artificial turf playing fields have been installed nationally.More than 1,200 were installed in the U.S. in 2013 alone, according to the industry group the Synthetic Turf Council.
Most synthetic turf systems installed today include a drainage layer, a multi-layered backing system, and resilient "grass" blades that are infilled with a granular filler to resemble natural turf. "Infilled" means that the man-made grass blades are interspersed with a top soil created with sand and/or granulated recycled tire rubber or other infill materials that provide the necessary stability, uniformity, and resiliency. Each blade customarily stands above the infill material. The typical blade length and system characteristics are determined by the specific activity requirements. In some applications, the synthetic turf system includes a pad or elastic layer underneath the turf, often in combination with lower pile height and less infill.
The quality of the raw materials is crucial to the performance of turf systems. Almost anything used as a carpet backing has been used for the backing material, from jute to plastic to polyester. High quality artificial turf uses polyester tire cord for the backing.
The fibers that make up the blades of "grass" are made of nylon or polypropylene and can be manufactured in different ways. The nylon blades can be produced in thin sheets that are cut into strips or extruded through moulds to produce fibers with a round or oval cross-section. The extruded product results in blades that feel and act more like biological grass.
Cushioning systems are made from rubber compounds or from polyester foam. Rubber tires are sometimes used in the composition of the rubber base, and some of the materials used in backing can come from plastic or rubber recycling programs. The thread used to sew the pads together and also the top fabric panels has to meet the same criteria of strength, colour retention, and durability as the rest of the system. Care and experience must also be applied to the selection of the adhesives used to bond all the components together.
Crumb Rubber is derived from scrap car and truck tires that are ground up and recycled. Two types of crumb rubber infill exist: Ambient and Cryogenic. Together these make up the most widely used infill in the synthetic sports field and landscape market. Crumb rubber infill is substantially metal free, and, according to the STC (Synthetic Turf Council) Guidelines for Crumb Rubber Infill, should not contain liberated fiber in an amount that exceeds .01% of the total weight of crumb rubber.
Coated Rubber Infill:
Both ambient and cryogenic rubber can be coated with colorants, sealers, or anti-microbial substances if desired. Coated rubber provides additional aesthetic appeal, reduction of dust by products during the manufacturing process and complete encapsulation of the rubber particle.
EPDM (Ethylene Propylene Diene Monomer) is a polymer elastomer with high resistance to abrasion and wear and will not change its solid form under high temperatures. Typical EPDM colours are green and tan. EPDM has proven its durability as an infill product in all types of climates. Its excellent elasticity properties and resistance to atmospheric and chemical agents provide a stable, high performance infill product.
There are several organic infills available in the North American market, all utilizing different organic components, such as natural cork and/or ground fibers from the outside shell of the coconut. These products can be utilized in professional sports applications as well as for landscaping. At the end of its life cycle it can be recycled directly into the environment.
Sand (Silica) Infill:
Pure silica sand is one of the original infilling materials utilized in synthetic turf. This product is a natural infill that is non-toxic, chemically stable and fracture resistant. Silica sand infills are typically tan, off-tan or white in colour and - depending upon plant location – may be round or sub-round in particle shape. As a natural product there is no possibility of heavy metals, and the dust/turbidity rating is less than 100. It can be used in conjunction with many other infills on the market to provide a safe and more realistic playing surface. The round shape plays an integral part in the synthetic turf system. It is important that silica sand have a high purity (greater than 90%) to resist crushing and absorption of bacteria and other field contaminants. Silica sand can either be coated with different materials as a standalone product or can be used to firm up in combination with traditional crumb rubber infill systems.
Coated Silica Sand Infill:
his class of infill consists of coated, high-purity silica sand with either a soft or rigid coating specifically engineered for synthetic turf. These coatings are either elastomeric or acrylic in nature (non-toxic) and form a bond with the sand grain sealing it from bacteria to provide superior performance and durability over the life of a field. Coated sand is available in various sizes to meet the application’s needs.
Depending on the amount and type of infill, coated sands can either be used with or without a pad and are available in various colours. All of the coatings are non-toxic and are bonded to the quartz grain for superior performance and durability over the life of your field. These materials are typically used as a homogenous infill which provides both ballast and shock absorbing qualities to a synthetic turf application.
hermo plastic elastomer (TPE) infill is non-toxic, heavy metal free, available in a variety of colours that resist fading, very long lasting, and 100% recyclable and reusable as infill when the field is replaced. TPE infill, when utilizing virgin-based resins, will offer consistent performance and excellent g-max over a wide temperature range.
The "grass" part of a turf system is made with the same tufting techniques used in the manufacture of carpets.
1. The first step is to blend the proprietary ingredients together in a hopper. Dyes and chemicals are added to give the turf its traditional green color and to protect it from the ultraviolet rays from the sun.
2. After the batch has been thoroughly blended, it is fed into a large steel mixer. The batch is automatically mixed until it has a thick, taffy-like consistency.
3. The thickened liquid is then fed into an extruder, and exits in a long, thin strand of material.
4. The strands are placed on a carding machine and spun into a loose rope. The loose ropes are pulled, straightened, and woven into yarn. The nylon yarn is then wound onto large spools.
5. The yarn is then heated to set the twisted shaped.
6. Next, the yarn is taken to a tufting machine. The yarn is put on a bar with skewers (a reel) behind the tufting machine. It is then fed through a tube leading to the tufting needle. The needle pierces the primary backing of the turf and pushes the yarn into the loop. A looper, or flat hook, seizes and release the loop of nylon while the needle pulls back up; the backing is shifted forward and the needle once more pierces the backing further on. This process is carried out by several hundred needles, and several hundred rows of stitches are carried out per minute. The nylon yarn is now a carpet of artificial turf.
7. The artificial turf carpet is now rolled under a dispenser that spreads a coating of latex onto the underside of the turf. At the same time, a strong secondary backing is also coated with latex. Both of these are then rolled onto a marriage roller, which forms them into a sandwich and seals them together.
8. The artificial turf is then placed under heat lamps to cure the latex.
9. The turf is fed through a machine that clips off any tufts that rise above its uniform surface.
10. Then the turf is rolled into large v/lengths and packaged. The rolls are then shipped to the wholesaler.
Artificial turf installation and maintenance is as important as its construction.
1. The base of the installation, which is either concrete or compacted soil, must be levelled by a bulldozer and then smoothed by a steam roller. Uneven surfaces will still be evident once the turf is applied.
2. For outdoor applications, intricate drainage systems must be installed, since the underlying surface can absorb little, if any, rainwater.
3. Turf systems can be either filled or unfilled. A filled system is designed so that once it is installed, a material such as crumbled cork, rubber pellets, or sand (or a mixture) is spread over the turf and raked down in between the fibers. The material helps support the blades of fiber, and also provides a surface with some give, that feels more like the soil under a natural grass surface. Filled systems have some limitations, however. Filling material like cork may break down or the filling material can become contaminated with dirt and become compacted. In either case the blades are no longer supported. Maintenance may require removing and replacing all of the fill.
A synthetic turf field usually has a higher upfront cost, but the field often pays for itself over 3-4 years, proving to be a highly cost-effective investment. Synthetic turf fields are typically utilized for about 3,000 hours of play per year, with no "rest” required, the equivalent of three to four well-maintained natural turf fields. In addition, synthetic turf maintenance costs are two to three times less than natural turf, since no mowing, irrigation or chemicals are needed. Because of its consistent availability, a synthetic turf field is also a reliable source of rental revenue for schools and communities.
According to Cory Jenner, a landscape architecture professional in Syracuse, N.Y., the cost of installing and maintaining a synthetic turf sports field over a 20-year period (including one replacement field) is over three times less expensive per event than the cost of a grass field over the same period of time. This is because many more events can be held on a synthetic turf sports field. "Financially speaking, artificial turf is more cost-effective over time,” Jenner said. This cost per event advantage is validated by other authorities and field owners.
Synthetic turf has ability to hold up under very heavy use. While natural turf shouldn’t be played on during or immediately after a rain storm, after the application of pesticides and fertilizers, or during the months when grass doesn’t grow, synthetic turf is always ready for play. Regular maintenance is important to enable synthetic turf to withstand the heavy use that it is often subjected to.
An Introduction to Artificial Turf (Synthetic Grass) Artificial turf is the material used in making artificial grass. Artificial grass is often seen in playgrounds and parks. It is a recent trend to have artificial grass in lawns and outdoor spaces. It is a replacement to natural grass. The reason why turf is used is that it is easy to maintain. Natural grass grows fast and needs regular chopping and maintenance. Apart from this, artificial turf always looks fresh and has no effect of the changing seasons. They do not need to be watered like natural grass in order to remain new and fresh.
Artificial turf is an excellent option in places where it is not possible to have natural grass growth. This is why more people are choosing an artificial turf over natural grass. Artificial turf consists of synthetic fibers. Artificial turf first gained importance in the 1960s. Since then its popularity and liking has increased among people. Today, artificial turfs offer sand and recycled rubber. In many sports like football, baseball and field hockey we see the use of artificial turf in the stadium. These grass substitutes also have some downsides. These include: use of petroleum, limited life and toxic as components. Artificial turf continues to grow in its use with many people trying it as a substitute to natural grass.
The demerits of older turfs can be prevented by taking correct measures as:
1.Test turf that has fibers that are abraded, faded or broken, contains visible dust, and that is made from nylon or nylon-blend fibers.
2.If the dust contains more than 400 ppm lead, do not allow turf access to children under the age of 6 years.
3.After playing on the field, individuals are encouraged to perform aggressive hand and body washing for at least 20 seconds using soap and warm water.
4. Eating while on the field or turf product is discouraged.
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