Hook-and-loop fasteners, hook-and-pile fasteners or touch fasteners , consist of two components: typically, two strips of cloth ( or, alternatively, rounded "dots" or boxes) attached (stitched or attached) to the opposite surface for fastening. The first component has a small hook, the second feature has a smaller loop. When both are pressed together, the hook catches in the loop and two pieces tighten or bind temporarily. When separated, by pulling or peeling two separate surfaces, the strip makes a distinctive "ripping" sound.
Hook-and-loop fasteners are often referred to by generic trademarks Velcro .
Video Hook-and-loop fastener
Histori
The original hook-and-loop fastener was conceived in 1941 by the Swiss engineer George de Mestral. The idea came to him one day after returning from a hunting trip with his dog in the Alps. He looked closer at the burs (burdock) that kept sticking to his clothes and his dog's fur. He examines them under a microscope, and records hundreds of their "hooks" that capture anything with a circle, such as clothing, animal fur, or hair. He saw the possibility of binding two materials upside down in a simple way if he could find a way to double the hook and loop. Hook-and-loop is seen by some as Steven Vogel or Werner Nachtigall as the prime example of inspiration from nature or the copying of natural mechanisms (called bionics or biomimesis).
At first people refused to take De Mestral seriously when he took his idea to Lyon, which at that time became the center of weaving. He managed to get the help of a weaver, who made two successful cotton pieces. However, cotton quickly runs out, so DeMestral switches to synthetic fibers. He chose nylon as the best synthetic, which has several advantages: not breaking, rotting, or pulling molds, and can be produced with various thread thicknesses. Nylon just discovered, and through trial and error de Mestral finally found that, when sewn under the heat infrared light, nylon forms a small hook shape. However, he has not found a way to mechanize the process, and to create a looped edge. He then discovers that nylon threads, when woven in loops and heat treated, retain their shape and hold; However, the rounds should be cut in the right places so they can be tied up and released many times. On the verge of surrender, a new idea came to him. He buys a pair of scissors and trims the top of the loop, thus creating a hook that will fit perfectly with the loop in the pile.
Mechanization of the hook procession takes eight years, and it takes another year to create a loom that trims the loop after weaving it. Overall, it took ten years to create a successful mechanization process.
De Mestral filed his idea for a patent in Switzerland in 1951, granted in 1955. Within a few years he acquired a patent and began to open stores in Germany, Switzerland, England, Sweden, Italy, the Netherlands, Belgium and Canada.. In 1957 he branched out to the textile center of Manchester, New Hampshire in the United States.
Columnist Sylvia Porter made the first mention of the product in her column Value of Your Money on August 25, 1958, writes, "With the understandable enthusiasm that I am giving you today an exclusive report on this news: A 'zipper zipper' has been discovered - finally, new binding devices are in many ways potentially more revolutionary than zips a quarter of a century ago. "
A Montreal company, Velek, Ltd., obtains exclusive rights to market products in North and South America, as well as in Japan, with American Velcro, Inc. from New Hampshire, and Velcro Sales of New York, marketing the "zipperless zipper" in the United States.
DeMestral gained patents in many countries right after creating fasteners, as it expects high demand soon. Partly because of its cosmetic appearance, hook-and-loop integration into the textile industry takes time. At that time, the fasteners looked like they were made of scraps of cheap fabric, and thus were not sewn into clothing or widespread use when debuting in the early 1960s. It is also seen as impractical.
A number of Velcro Corporation products were displayed at a fashion show at the Waldorf-Astoria hotel in New York in 1959, and the fabrics got the first pause when used in the aerospace industry to help astronaut maneuvers in and out of large space clothing.. However, this reinforces the view among the public that hook and loop is something with very limited utilitarian utility. The use of the next great hooks and screw saws is with skiers, who see similarities between their costumes and astronauts, and thus see the advantages of a suit that is easier to remove. Scuba and marine equipment soon followed. After seeing astronauts storing food bags on the wall, children's clothing makers came. As the only touch fastener became widely used after NASA's adoption, NASA was popular - and wrongly - credited with its invention.
In the mid 1960's hook-and-loop fasteners were used in futuristic creation of fashion designers such as Pierre Cardin, AndrÃÆ'Â © CourrÃÆ'¨ges and Paco Rabanne.
Further improvements include strengthening the filament by adding polyester.
In 1978, Mestral's patent expired, driving inexpensive imitation floods from Taiwan, China, and South Korea to the market. Today, the trademark is the subject of more than 300 trademark registrations in over 159 countries. George deÃ, Mestral was inaugurated to be the inventor of national fame for his discovery.
The major breakthrough by George de Mestral is to think of eye and eye closures on a very reduced scale. Hook-and-eye fasteners have been common for centuries, but what's new about hook-and-loop fasteners is the miniaturization of hooks and eyes. Shrinking the hook causes two other important differences. First, instead of one row of hooks, the touch fastener has a two-dimensional surface. This is necessary, because in reducing the size of the hook, the power is also inevitably reduced, thus requiring more hooks for the same strength. Another difference is that the hook-and-loop has an indeterminate fit between the hook and the eye. With larger hook-and-eye fasteners, each hook has its own eyes. On a scale as small as a hook-and-loop fastener, matching each of these hooks with the eye is impractical, leading to an indeterminate matching.
Maps Hook-and-loop fastener
Strength
Various constructions and strengths are available. Some of the touch fasteners are strong enough so that a 2 inch square piece (5 ÃÆ'â € Ã, Â ± cm) is enough to support a 175 pound (80 kg) load. Fasteners made of Teflon loops, polyester hooks, and glass mats are used in aerospace applications, eg. on the space shuttle. The strength of the bond depends on how well the hooks are embedded in the loop, how many surfaces are in contact with the hooks, and the nature of the style that pulls them apart. If a hook-and-loop is used to unite two rigid surfaces, such as panels and car body frames, the bonds are very strong because each style that pulls the parts is spread evenly across all the hooks. Also, any force that drives the pieces is disproportionately applied to attract more hooks and loops. Vibration can cause rigid pieces to increase the bond. Full-body hook-and-loop clothing has been created that can hold a person to the appropriate closed wall.
When one or both sections are flexible, for example, a pocket fold, pieces can be pulled apart by exfoliating actions that apply relatively little force to the latch at a time. If a flexible piece is pulled in a direction parallel to the surface plane, then the force is spread evenly, as with rigid pieces.
Three ways to maximize bond strength between two flexible pieces are:
- Increase bond area, e.g. use larger pieces.
- Make sure that the force is applied parallel to the surface area of ​​the fastener, such as bending angles or pulleys.
- Add the number of hooks and loops per unit area.
Shoe closure can withstand large styles with just a few hook and loop fasteners. This is because the string is wrapped through the slot, halving the force on the bond by acting as a pulley system (thus gaining mechanical advantage), and further absorbs some force in friction around the tight bend. This layout also ensures that the styles are parallel to the strip.
Advantages and disadvantages
Touch fasteners are easy to use, safe, and maintenance free. There is only a slight decrease in effectiveness even after much fastening and unfastenings. The tearing sound it generates can also be useful against pickpockets.
There are also some drawbacks: it tends to pile up hair, dust, and hair on the hook after several months of regular use. Loops may become elongated or damaged after longer use. Kait often attaches to clothing items, especially loose-woven items such as sweaters. This outfit may be damaged when someone tries to remove the hook-and-loop, even if both sides are separated slowly. The tearing sound made by the fast hook-and-loop fasteners makes it unsuitable for some applications. For example, a hiding soldier does not want to warn the enemy into his position by opening his pockets. It also absorbs moisture and sweat when used next to the skin, which means it will smell if not washed.
Textiles may contain chemicals or compounds, such as dyes, which can cause allergies in sensitive people. Some products have been tested in accordance with Oeko-tex certification standards, which impose restrictions on textile chemicals to address human ecological security issues.
Apps
Because of its ease of use, hook-and-loop fasteners have been used for a variety of applications where temporary ties are required. It's very popular in clothes where it replaces buttons or zippers, and as a shoe fastener for children who have not learned to tie shoelaces. Touch fasteners are used in adaptive clothing, designed for people with disabilities, the elderly, and the weak, who may have difficulty dressing themselves because of the inability to manipulate closures such as buttons and zippers.
Touch fasteners unite the human heart during the first artificial heart surgery, and are used in nuclear power plants and army tanks to hold a flashlight against the wall. The car uses it to tie headliners, floor mats and speaker covers. Used at home while installing curtains, holding the carpet in place and installing upholstery. It closes backpacks, briefcases and notebooks, secures bags, and holds disposable diapers, and diaper covers for cloth diapers, in babies. It is an integral part of the rugby game tag, and is used in dog surfboards and orthopedic braces.
NASA uses significant touch fasteners. Each flying spacecraft is equipped with a special ten thousand-inch tie made of Teflon loops, polyester hooks, and glass backing. Touch fasteners are widely used, from astronaut settings, to retaining equipment. In near-weight conditions in orbit, hook-and-loop fasteners are used to hold objects temporarily and keep them from drifting. A patch is used inside an astronaut's helmet where it serves as a nose rake. During mealtimes, the astronauts use trays that stick to their thighs using springs and tighten. Touch fasteners are also used on top of the International Space Station.
Variations on touch fasteners
The Slidingly Engaging Fastener was developed to address some of the problems with common hook-and-loop fasteners. Heavy duty variants (such as "Dual Lock" or "Duotec") feature a mushroom-shaped stem on each binder face, giving an audible snap when two partner faces. Strong pressure-sensitive adhesives bind each component to its substrate.
There is a quiet touch toner version, sometimes called Quiet Closures.
Standard
- ASTM D5169-98 (2010) Standard Test Method for Shear Strength (Dynamic Method) Fasteners Touch Hooks and Loops
- ASTM D5170-98 (2010) Standard Test Method for Peel Strength (Method "T") Fasteners Touch Hooks and Loops
- ASTM D2050-11 Standard Terminology Relating to Fasteners and Closures Used in Textiles
Jump
Velcro jumping is a game where people who wear clothing wearing hooks wear leaps and run as high as they can to a closed wall of circles. The walls are inflated, and look similar to other inflatable structures. It is not necessarily completely enclosed in the material - often there will be a vertical strip of hooks. Sometimes, instead of jumps running, people use small trampolines.
TV host David Letterman immortalized this for 28 February 1984 episode of Late Night with David Letterman on NBC. Letterman proved that enough of a man's material could be thrown into the wall and stuck, by performing this feat during a television broadcast. This puts Velcro brand binder in the national spotlight.
Jump past David Letterman. Entertainment companies rent walls and jumpsuits for $ 400- $ 500 a day. It is also done routinely in pubs in New York and New Zealand, where it is a competition to see how high a person can get their feet on the ground. Jeremy Bayliss and Graeme Smith of Cri Bar and Grill in Napier, New Zealand, started after seeing American astronauts stuck to the wall during a space flight. They created their own equipment for a "human flying" contest, and sold it to several others in New Zealand.
The game moved to the US after Sports Illustrated published a story in it in 1991. Adam Powers and Stephen Wastell from Perfect Tommy's bar in New York City read about the game, and soon became a distributor of Human Bar Fly equipment from the United States. Wall-jumping is now in dozens of New Zealand bars and is said to be one of the favorite bar activities there.
In popular culture
- 1969-1972 - Velcro brand fasteners are used on clothing, sample collection bags, and lunar vehicles during all Apollo program missions to the Moon.
- 1984 - David Letterman wore a hatch-and-loop suit and jumped from a trampoline to a wall covered in the product during an interview with industry sales director of the United States Velcro Companies.
- 1996 - In the John Frankenheimer film Island Dr. Moreau, Moreau's assistant jokingly claimed that the doctor won the Nobel Prize for having invented Velcro. 1997 - Binders have become part of repeated jokes in various media where it is claimed that modern humans will not be able to create them, and that is actually a form of advanced technology. For example, claim K in Men in Black that Velcro was originally a foreign technology,
- 2002 - The Star Trek: Enterprise episode "Carbon Creek" describes Velcro as introduced to human society by Vulcan in 1957. One of Vulcan in this episode was named "Mestral", after the actual inventor and founder of the bond brand.
- 2004 - One of the characters in the film Garden State made a huge fortune from creating "Silent Velcro". 2016 - As an April Fool's joke, Lexus introduces the "Variable Load Coupling Rear Orientation (V-LCRO) Seats", a technology that connects drivers to seats with the Velcro Brand product to allow for more aggressive turns.
References
Source of the article : Wikipedia
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