Polyvinyl chloride

Polyvinyl chloride, more correctly but unusually poly(vinyl chloride), commonly abbreviated PVC, is the third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene.

PVC comes in two basic forms: rigid (sometimes abbreviated as RPVC) and flexible. The rigid form of PVC is used in construction for pipe and in profile applications such as doors and windows. It is also used for bottles, other non-food packaging, and cards (such as bank or membership cards). It can be made softer and more flexible by the addition of plasticizers, the most widely used being phthalates. In this form, it is also used in plumbing, electrical cable insulation, imitation leather, signage, inflatable products, and many applications where it replaces rubber.

Pure poly (vinyl chloride) is a white, brittle solid. It is insoluble in alcohol but slightly soluble in tetrahydrofuran.

Discovery

PVC was accidentally synthesized in 1872 by German chemist Eugen Baumann. The polymer appeared as a white solid inside a flask of vinyl chloride that had been left exposed to sunlight. In the early 20th century the Russian chemist Ivan Ostromislensky and Fritz Klatte of the German chemical company Griesheim-Elektron both attempted to use PVC in commercial products, but difficulties in processing the rigid, sometimes brittle polymer thwarted their efforts. Waldo Semon and the B.F. Goodrich Company developed a method in 1926 to plasticize PVC by blending it with various additives. The result was a more flexible and more easily processed material that soon achieved widespread commercial use.

Life

Life is a characteristic distinguishing physical entities having biological processes (such as signaling and self-sustaining processes) from those that do not, either because such functions have ceased (death), or because they lack such functions and are classified as inanimate. Various forms of life exist such as plants, animals, fungi, protists, archaea, and bacteria. The criteria can at times be ambiguous and may or may not define viruses, viroids or potential artificial life as living. Biology is the primary science concerned with the study of life, although many other sciences are involved.

Throughout history there have been many theories about life including materialism, hylomorphism and vitalism. Even today it is a challenge for scientists and philosophers to define life. The smallest contiguous unit of life is called an organism. Organisms are composed of one or more cells, undergo metabolism, maintain homeostasis, can grow, respond to stimuli, reproduce (either sexually or asexually) and, through evolution, adapt to their environment in successive generations. A diverse array of living organisms can be found in the biosphere of Earth, and the properties common to these organisms are a carbon- and water-based cellular form with complex organization and heritable genetic information.

Hacks

Hacks may refer to:

See also

Rubber band

A rubber band, also known as a binder, elastic band, lackey band, laggy band, gum band, or elastic, is usually ring shaped and commonly used to hold multiple objects together. The rubber band was patented in England on March 17, 1845 by Stephen Perry.Mesoamericans (such as Aztecs and Mayans) were using natural rubber products by 1600 B.C.; they mixed latex with other materials to get desired properties. In 1839, Charles Goodyear developed vulcanization which is used to make rubber today. Most rubber bands are manufactured out of natural rubber. Rubber bands come in a variety of sizes.

Manufacturing

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

Material

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

Plastic pipework

Plastic pipework is used for the conveyance of drinking water, waste water, chemicals, heating fluid and cooling fluids, foodstuffs, ultra-pure liquids, slurries, gases, compressed air and vacuum system applications.

Standards

Plastic pipe systems fulfil a wide variety of service requirements. Product standards for plastics pipe systems are prepared within the standards committee known as CEN/TC155. These requirements are precisely described in a complete set of European Product Standards for each application alongside their specific characteristics.

For example:

Conveyance of drinking water: Hygienic requirements

Conveyance of gas: Highest Safety requirements

Plastic pipes for radiant heating and floor heating: Temperature resistance over decades

Sewer applications: High chemical resistance.

Plastic pipes are perfectly capable of fulfilling the specific requirement for each application. They do so with a high level of performance over a long lifetime and with reliability and safety.