Rubber band bracelets: be in the loop!

        Those colorful loops of rubber should be quite familiar to you by now. Yes, we are talking about rubber band bracelets. They have become ubiquitous in the last couple of years. You can see them on the wrists of Tsunami aid workers, citizens campaigning for a cause, and even the on wrists of school children.

       The rubber band bracelets have become the most-preferred and the most inexpensive way to show your support for a cause, or to donate to charity, or to raise awareness about an issue or a disease. You can see them used for extremely different purposes, such as to proclaim one's religious affiliation, or as a fashion statement! The rubber band bracelet is the modern way of wearing your heart on your sleeve, er wrist!

        What are rubber band bracelets? They are simply loops of solid rubber, worn on the wrist by stretching and sliding them over the palm of one's hands. They come in any color imaginable -- yellow, orange, blue, green, black, pink... Some are translucent, others glow in the dark... And they are worn in support of many a message or cause -- they are as versatile as they are stretchable! Not all rubber band bracelets are rubber, though. Some of them are made of silicone.

       

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You can have any message stamped over the rubber band bracelets, or designs crafted on them. In fact, some of the latest rubber band bracelets sport more than one message! Rubber band bracelets usually sell for $1-5 a piece, and can be ordered online from many Web sites, in multiples of five hundred, or smaller packs of a dozen or more. The manufacturers often give discounts for the larger orders.

Twilight Team Edward Rubber Bracelets 2 Pack

         The most famous of the rubber band bracelets is the yellow 'Livestrong' wristband worn by cycling champion and cancer survivor Lance Armstrong. The pink ones are worn to show support to breast cancer patients. SHeDAISY's 'Come Home Soon' yellow rubber band bracelets (named for the group's Top 15 single) with the words 'Come Home Soon' stamped on them are highly popular among relatives of American servicemen.

Official Live Strong Lance Armstrong Yellow Cancer Livestrong Rubber Wristband Bracelet Youth Size (Lot of 6 for One Price)

       The rubber band bracelet is a very useful and inexpensive tool for crowd control: it is used as a cheap identifying device in restricted access events attended by large numbers of people, such as music concerts. The rubber band bracelets are also issued by hospitals to their patients as identifying devices with some basic medical information stamped on them.

        So what makes these rubber band bracelets so popular? Sociologists say people have always used amulets in times of trouble. Now we are just using them in a more positive way. Yes, rubber band bracelets are more than simple loops of rubber; they represent the human urge to fight and survive great odds.

Silly Bandz (Animal Rubber Bands) Zoo Pack of 24

The History Of Rubber Bands

          The ancient Mayan people used latex in order to make hollow human figures, rubber balls, and as bindings used to secure the axe heads to their handles as well as for other functions. Latex is the result of various plants, the most important one being the rubber tree which when it is exposed to the air, it hardens into a springy mass. The Mayans learned to mix together the rubber sap with the juice coming from morning glory vines so that it became more elastic and durable.

       Later on, in 1736, a few rolled sheets of rubber were sent to France and in 1791; Samuel Peal invented a new way of waterproofing cloth by mixing turpentine with rubber. Another British inventor by the name of Joseph Priestly discovered that the rubber could be used to erase pencil marks. Thomas Hancock is the person who invented the British rubber industry. He designed the masticator – a machine capable of shredding rubber scraps thus allowing the rubber to be recycled after being formed into blocks or rolled into sheets. In the 19th century, to be more specific in the 1820s, he patented elastic fastenings for shoes, suspenders, stockings and gloves.

           In order to help preserve the rubber, Hancock invented the masticator. The first one was a wooden machine that used a hollow cylinder studded with teeth. In 1823, Charles Macintosh patented his method of making waterproof garments using rubber dissolved in coal-tar naphtha for cementing two pieces of cloth together. A few years later in 1837 he patented the masticator which was used on a large scale since then. The wooden masticator turned into a steam-driven metal machine which was used to supply Macintosh's factory with masticated rubber.

          On March 17, 1845, a man by the name of Stephen Perry belonging to the rubber manufacturing company Messers Perry and Co., Rubber Manuf London patented the first rubber bands made of vulcanized rubber. He invented them in order to hold papers and envelopes together. 31 years later, Sir Henry Wickham collected about 70,000 rubber tree seeds from the Para rubber tree. Commercial rubber production now takes place in Malaysia, Thailand, Indonesia, and Sri Lanka (but not significantly in South America). One year later, in 1877, Chapman Mitchell discovered that the rubber can be recycled into new products.

          In the present, approximately ¾ of the rubber in production is made out of crude oil. There are 20 grades of synthetic rubber and intended end use determines the selection. Generally speaking, in order to make synthetic rubber, byproducts of petroleum refining called styrene and butadiene are mixed in a reactor containing soapsuds. From this, a milky looking liquid results and the latex is coagulated from the liquid, resulting in rubber "crumbs" which are purchased by numerous manufacturers and later on, melted in a variety of products.

        In the world today, there is only one kind of natural rubber. Due to the reason that the rubber plants are located in hot, damp regions near the Equator, 90% of the rubber production takes place in the Southeast Asian countries: Indonesia, Thailand and Malaysia. Because the production in Indonesia has dropped in the last few years, several plantations were built in Africa in order to fill in the gap.

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Rubber band

From Wikipedia, the free encyclopedia

Charles Leonard Rubber Bands, Tissue-style Box, #32, Beige/Natural, 58132

     Do you know rubber bands or animal bands or wristband.In my opinion it is may be the same.So i try to searching on all web to collect and show to everyone who love bands...

     Firstly, i will let you to know about "rubber bands".A rubber band (in some regions known as a binder, elastic band, lackey band, laggy band, lacka band or gumband) is a short length ofrubber and latex formed in the shape of a loop. They come in multiple colors, including tan, pink, blue, red, yellow, orange, fuschia, and green. Such bands are typically used to hold multiple objects together. The rubber band was patented in England on March 17, 1845 by Stephen Perry.^[1][2]

Manufacturing

Rubber bands are made by extruding the rubber into a long tube to provide its general shape, putting the tubes on mandrels and curing the rubber with heat, and then slicing it across the width of the tube into little bands.

Material

While other rubber products may use synthetic rubber, rubber bands are primarily manufactured using natural rubber because of its superior elasticity^[2].

Natural rubber originates from the sap of the rubber tree. Natural rubber is made from latex which is acquired by tapping into the bark layers of the rubber tree. Rubber trees belong to the spurge family (Euphorbiaceae) and live in warm, tropical areas. Once the latex has been “tapped” and is exposed to the air it begins to harden and become elastic, or “rubbery.” Rubber trees only survive in hot, humid climates near the equator and so the majority of latex is produced in the Southeast Asian countries of Malaysia, Thailand and Indonesia.

Today more than three quarters of all rubber products are made from synthetic rubber^[2]. Modern synthetic rubber is made by mixing petroleum byproducts in a reactor with soapsuds which produces milky liquid latex. The liquid is then coagulated into rubber chunk and then sold to rubber manufacturers who in turn melt the rubber down and pour it into molds to create various products. The advancement of manufacturing and increased production of synthetic rubber is due partially to the United States being cut off from rubber supplies during World War II.

Rubber Band Sizes

Measuring

Measuring a rubber band

A rubber band has three basic dimensions: Length, width, and thickness. (See picture.)

A rubber band's length is half its circumference. Its thickness is the distance from the inner circle to the outer circle.

Lay a rubber band down so that it makes a rectangle. The band's width is the height of that band. If one imagines a rubber band in manufacture, that is, a long tube of rubber on a mandrel, before it is sliced into rubber bands, the band's width is how far apart the slices are cut.

[edit]

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Temperature Effects

Temperature affects the elasticity of a rubber band in an unusual way. Heating makes the rubber band contract. And if frozen they expand

Rubber Band Size Numbers

A rubber band is given a [quasi-]standard number based on its dimensions.

Generally, rubber bands are numbered from smallest to largest, width first. Thus, rubber bands numbered 8-19 are all 1/16 inch wide, with length going from 7/8 inch to 3 1/2 inches. Rubber band numbers 30-34 are for width of 1/8 inch, going again from shorter to longer. For even longer bands, the numbering starts over for numbers above 100, again starting at width 1/16 inch.

The origin of these size numbers is not clear and there appears to be some conflict in the "standard" numbers. For example, one distributor^[5] has a size 117 being 1/16 inch wide and a size 127 being 1/8 inch wide. However, an OfficeMax size 117^[6] is 1/8 inch wide. A manufacturer^[7] has a size 117A (1/16 inch wide) and a 117B (1/8 inch wide). Another distributor^[8] calls them 7AA (1/16 inch wide) and 7A (1/8 inch wide) (but labels them as specialty bands).

Rubber Band Sizes
Size	Length (in)	Width (in)	Thickness (in)
10	1.25	1/16	1/32
12	1.75	1/16	1/32
14	2	1/16	1/32
31	2.5	1/8	1/32
32	3	1/8	1/32
33	3.5	1/8	1/32
61	2	1/4	1/32
62	2.5	1/4	1/32
63	3	1/4	1/32
64	3.5	1/4	1/32
117	7	1/16	1/32

Thermodynamics

An interesting effect of rubber bands in thermodynamics is that stretching a rubber band will produce heat (press it against your lips), while stretching it and then releasing it will produce anendothermic reaction, causing it to appear "cooler". This phenomenon can be explained with Gibb's Free Energy. Rearranging ΔG=ΔH-TΔS, where G

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is the free energy, H is the enthalpy, and S is the entropy, we get TΔS=ΔH-ΔG. Since stretching is nonspontaneous, as it requires an external heat, TΔS must be negative. Since T is always positive (it can never reach absolute zero), the ΔS must be negative, inferring that the rubber in its natural state is more entangled (less microstates) than when it is under tension. Thus, when the tension is removed, the reaction is spontaneous, leading ΔG to be negative. Consequently, the cooling effect must result in a positive ΔG, so ΔS will be positive there.^[9][10]

[edit]Red rubber bands

Main article: Royal Mail rubber band

In 2004 in the UK, following complaints from the public about postmen and women causing litter by discarding the rubber bands which they used to keep their mail together, the Royal Mailintroduced red bands for their workers to use: it was hoped that, as the bands were easier to spot than the traditional brown ones and since only the Royal Mail used them, employees would see (and feel compelled to pick up) any red bands which they had inadvertently dropped. Currently, some 342 million red bands are used every year.

Rubber Band Paddle Boat

[edit]Model use

Rubber bands have long been one of the methods of powering small free-flight model aeroplanes, the rubber band being anchored at the rear of the fuselage and connected to the propellerat the front. To 'wind up' the 'engine' the propeller is repeatedly turned, twisting the rubber band. When the propeller has had enough turns, the propeller is released and the model launched, the rubber band then turning the propeller rapidly until it has unwound.

One of the simplest examples of a "Rubber Band Plane" is the Squirrel designed by Darcy Whyte. Squirrel Simple Model Plane

One of the earliest to use this method was pioneer aerodynamicist George Cayley, who used them for powering his small experimental models. These 'rubber motors' have also been used for powering small model boats.

Amazing Rubber Band Cars: Easy-to-Build Wind-Up Racers, Models, and Toys