Rubber band

Rubber band

Five rubber bands
A rubber band (in some regions known as a binder, elastic band, lackey band, "laggy band" or gumband) is a short length of rubber and latex formed in the shape of a loop. Such bands are typically used to hold multiple objects together. Some are used as weapons. The rubber band was patented in Australia

Rubber Band
Background
Rubber bands are one of the most convenient products of the twentieth century, used by numerous individuals and industries for a wide variety of purposes. The largest consumer of rubber bands in the world is the U.S. Post Office, which orders millions of pounds a year to use in sorting and delivering piles of mail. The newspaper industry also uses massive quantities of rubber bands to keep individual newspapers rolled or folded together before home delivery. Yet another large consumer is the agricultural products industry. The flower industry buys rubber bands to hold together bouquets or uses delicate bands around the petals of flowers (especially tulips) to keep them from opening in transit. Vegetables such as celery are frequently bunched together with rubber bands, and the plastic coverings over berries, broccoli, and cauliflower are often secured with rubber bands. All in all, more than 30 million pounds of rubber bands are sold in the United States alone each year.

Manufacturing

The manufacturing process is a complicated one which involves 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 along the width of the tube into little bands.[1][2] While other rubber products may use synthetic rubber, rubber bands are still primarily manufactured using natural rubber because of its superior elasticity.
Processing the natural latex
1 The initial stage of manufacturing the harvested latex usually takes place on the rubber plantation, prior to packing and shipping. The first step in processing the latex is purification, which entails straining it to remove the other constituent elements apart from rubber and to filter out impurities such as tree sap and debris.
2 The purified rubber is now collected in large vats. Combined with acetic or formic acid, the rubber particles cling together to form slabs.
3 Next, the slabs are squeezed between rollers to remove excess water and pressed into bales or blocks, usually 2 or 3 square feet (.6 or .9 square meter), ready for shipping to factories. The size of the blocks depends on what the individual plantation can accommodate.
Mixing and milling
4 The rubber is then shipped to a rubber factory. Here, the slabs are machine cut (or chopped) into small pieces. Next, many manufacturers use a Banbury Mixer, invented in 1916 by Femely H. Banbury. This machine mixes the rubber with other ingredients—sulfur to vulcanize it, pigments to color it, and other chemicals to increase or diminish the elasticity of the resulting rubber bands. Although some companies don't add these ingredients until the next stage (milling), the Banbury machine integrates them more thoroughly, producing a more uniform product.
5 Milling, the next phase of production, entails heating the rubber (a blended mass if it has been mixed, discrete pieces if it has not) and squeezing it flat in a milling machine.
Extrusion
6 After the heated, flattened rubber leaves the milling machine, it is cut into strips. Still hot from the milling, the strips are then fed into an extruding machine which forces the rubber out in long, hollow tubes (much as a meat grinder produces long strings of meat). Excess rubber regularly builds up around the head of each extruding machine, and this rubber is cut off, collected, and placed back with the rubber going into the milling machine.
Curing
7 The tubes of rubber are then forced over aluminum poles called mandrels, which have been covered with talcum powder to keep the rubber from sticking. Although the rubber has already been vulcanized, it's rather brittle at this point, and needs to be "cured" before it is elastic and usable. To accomplish this, the poles are loaded onto racks that are steamed and heated in large machines.
8 Removed from the poles and washed to remove the talcum powder, the tubes of rubber are fed into another machine that slices them into finished rubber bands. Rubber bands are sold by weight, and, because they tend to clump together, only small quantities can be weighed accurately by machines. Generally, any package over 5 pounds (2.2 kilograms) can be loaded by machine but will still require manual weighing and adjusting.