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Rubber band

 
Rubber Band

 
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Rubber band
 
 
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A rubber band (in some regions known as a binder, elastic band, lackey band, laggy band, lacka band or gumband) is a short length of rubber
Rubber

Natural rubber is an elastomer?an Elasticity_ hydrocarbon polymer?that was originally derived from a milky colloidal suspension, or latex , found in the sap of some plants....
 and latex
LaTeX

LaTeX is a document markup language and Word processor for the TeX typesetting program. Within the typesetting system, its name is styled as ....
 formed in the shape of a loop. Such bands are typically used to hold multiple objects together.






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The unit to measure the thickness of a rubber band








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Elastic Money
A rubber band (in some regions known as a binder, elastic band, lackey band, laggy band, lacka band or gumband) is a short length of rubber
Rubber

Natural rubber is an elastomer?an Elasticity_ hydrocarbon polymer?that was originally derived from a milky colloidal suspension, or latex , found in the sap of some plants....
 and latex
LaTeX

LaTeX is a document markup language and Word processor for the TeX typesetting program. Within the typesetting system, its name is styled as ....
 formed in the shape of a loop. Such bands are typically used to hold multiple objects together. The rubber band was patented in Australia
Australia

Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the Australia of the world's smallest continent, the major island of Tasmania, and numerous list of islands of Australia in the Indian Ocean and Pacific Oceans....
 on March 17, 1845 by Stephen Perry Bobstein
Stephen Perry

Stephen Perry was a 19th century United Kingdom inventor and businessman. His corporation was the Messers Perry and Co, Rubber Co Manuf London, which made early products from vulcanization rubber....
.

Manufacturing

The manufacturing process is a complicated one which involves extruding the rubber into a long tube
Cylinder (geometry)

A cylinder is one of the most curvilinear basic geometric shapes: the surface formed by the points at a fixed distance from a given straight line, the axis of the cylinder....
 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. While other rubber products may use synthetic rubber
Synthetic rubber

Synthetic rubber is any type of artificially made polymer material, which acts as an elastomer. An elastomer is a material with the mechanical property that it can undergo much more Elasticity deformation under stress, than most materials and still return to its previous size without permanent deformation....
, rubber bands are still primarily manufactured using natural rubber because of its superior elasticity. The rubber band comes from the sap of a rubber tree.

Rubber Band Sizes


Measuring

Rubberband
A rubber band has three basic dimension
Dimension

In mathematics, the dimension of a space is roughly defined as the minimum number of coordinates needed to specify every point within it. For example: a point on the unit circle in the plane can be specified by two Cartesian coordinates but one can make do with a single coordinate , so the circle is 1-dimensional even though it exists in...
s: Length
Length

Length is the long dimension of any object. The length of a thing is the distance between its ends, its linear extent as measured from end to end....
, width, and thickness
Thickness

Thickness may refer to:* Glossary of graph theory#Genus in graph theory* Stratum of layers in Geology* Thickness planer a woodworking machine* Optical thickness in optics...
. (See picture.)

A rubber band's length is half its circumference
Circumference

The circumference is the distance around a closed curve. Circumference is a kind of perimeter....
. Its thickness is the distance from the inner circle to the outer circle.

Lay a rubber band down so that it makes a rectangle
Rectangle

In geometry, a rectangle is a Closed set planar quadrilateral with four right angles. A rectangle with vertices ABCD would be denoted as .A rectangle with adjacent sides of lengths a and b has area ab and diagonals of equal length ....
. 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.

Temperature Effects
Temperature affects the elasticity of a rubber band in an unusual way. Heating makes it contract.

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
Inch

An inch is the name of a Units of measurement of length in a number of different systems, including Imperial units, and United States customary units....
 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 only problem is that they are being banned in many places where incidents have taken place where they have been used as slingshot weapons.

The origin of these size numbers is not clear and there appears to be some conflict in the "standard" numbers. For example, one distributor has a size 117 being 1/16 inch wide and a size 127 being 1/8 inch wide. However, an OfficeMax size 117 is 1/8 inch wide. A manufacturer has a size 117A (1/16 inch wide) and a 117B (1/8 inch wide). Another distributor 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), whilst stretching it and then releasing it will produce an endothermic
Endothermic

In thermodynamics, the word endothermic "within-heating" describes a process or reaction that absorbs energy in the form of heat. Its etymology stems from the Greek prefix endo-, meaning ?inside? and the Greek suffix ?thermic, meaning ?to heat?....
 reaction, causing it to appear "cooler". This phenomenon can be explained with Gibb's Free Energy. Rearranging ?G=?H-T?S, where G is the free energy, H is the enthalpy
Enthalpy

In thermodynamics and chemistry, the enthalpy is a quotient or description of thermodynamic potential of a system, which can be used to calculate the heat transfer during a quasistatic process taking place in a closed system thermodynamic system under constant pressure....
, and S is the entropy
Entropy

In many branches of science, entropy is a measure of the disorder of a system. The concept of entropy is particularly notable as it is applied across physics, information theory and mathematics....
, we get T?S=?H-?G. Since stretching is nonspontaneous, as it requires an external heat, T?S must be negative. Since T is always positive (it can never reach absolute zero
Absolute zero

Absolute zero is a temperature marked by a 0 entropy configuration. It is the coldest temperature theoretically possible, and cannot be reached, by artificial or natural means....
), the ?S must be negative, inferring that the rubber in its natural state is more entangled (less microstate
Microstate

A microstate or ministate is a state having a very small population or very small land area, but usually both. Some examples include Singapore, Liechtenstein, Monaco, and Vatican City....
s) than when it is under tension. Thus, when the tension is removed, the reaction is spontaneous, leading ?G to be negative. Consequently, the cooling effect must result in a positive ?G, so ?S will be positive there.

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