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Human papillomavirus infection ( HPV infection) is caused by a DNA virus from the Papillomaviridae family. [5] Many HPV infections cause no symptoms and 90% resolve spontaneously within two years. [1] In some cases, an HPV infection persists and results in either warts or precancerous lesions. [2] These lesions, depending on the site affected ...
- Human papillomavirus spread by direct contact
- None, warts
- Most people are infected at some point in time
William Bradley Pitt (born December 18, 1963) is an American actor and film producer. He is the recipient of various accolades, including two Academy Awards, two British Academy Film Awards, two Golden Globe Awards, and a Primetime Emmy Award. One of the most influential celebrities, Pitt appeared on Forbes ' annual Celebrity 100 list from 2006 ...
Pneumonoultramicroscopicsilicovolcanoconiosis is the longest word in the English language. The word can be analysed as follows: This word was invented in the daily meeting from the National Puzzlers' League (N.P.L.) by its president Everett M. Smith. The word featured in the headline for an article published by the New York Herald ...
- Uses
- History
- Physical Properties
- Copolymers
- Production
- Environmental Concerns
- Safety
- Bottle Processing Equipment
- Polyester Recycling
- See Also
Textiles
Polyester fibres are widely used in the textile industry. The invention of the polyester fibre is attributed to J. R. Whinfield. It was first commercialized in the 1940s by ICI, under the brand 'Terylene'. Subsequently E. I. DuPontlaunched the brand 'Dacron'. As of 2022, there are many brands around the world, mostly Asian. Polyester fibres are used in fashion apparel often blended with cotton, as heat insulation layers in thermal wear, sportswear and workwear and automotive upholstery.
Rigid packaging
Plastic bottles made from PET are widely used for soft drinks, both still and sparkling. For beverages that are degraded by oxygen, such as beer, a multilayer structure is used. PET sandwiches an additional polyvinyl alcohol (PVOH) or polyamide(PA) layer to further reduce its oxygen permeability. Non-oriented PET sheet can be thermoformed to make packaging trays and blister packs. Crystallizable PET withstands freezing and oven baking temperatures.: 1378 Both amorphous PET and BoPET are trans...
Flexible packaging
Biaxially oriented PET (BOPET) film (often known by one of its trade names, "Mylar") can be aluminized by evaporating a thin film of metal onto it to reduce its permeability, and to make it reflective and opaque (MPET). These properties are useful in many applications, including flexible food packaging and thermal insulation (such as space blankets).
PET was patented in 1941 by John Rex Whinfield, James Tennant Dickson and their employer the Calico Printers' Association of Manchester, England. E. I. DuPont de Nemours in Delaware, United States, first used the trademark Mylar in June 1951 and received registration of it in 1952.It is still the best-known name used for polyester film. The current...
PET in its most stable state is a colorless, semi-crystalline resin. However it is intrinsically slow to crystallize compared to other semicrystalline polymers. Depending on processing conditions it can be formed into either amorphous or crystalline articles. Its amenability to drawing makes PET useful in fibre and film applications. Like most arom...
PET is copolymerized with other diols or diacids to optimize the properties for particular applications. For example, cyclohexanedimethanol (CHDM) can be added to the polymer backbone in place of ethylene glycol. Since this building block is much larger (six additional carbon atoms) than the ethylene glycol unit it replaces, it does not fit in with...
Polyethylene terephthalate is produced from ethylene glycol (usually referred to in the trade as "MEG", for monoethylene glycol) and dimethyl terephthalate (DMT) (C6H4(CO2CH3)2) but mostly terephthalic acid (known in the trade as "PTA", for purified terephthalic acid). As of 2022, ethylene glycol is made from ethene found in natural gas, while tere...
Resource depletion
Compared to the use of petroleum as fuel, however, the amount of crude oil processed into PET is very small. The total production capacity of PET is around 30 million tons, compared to 4.2 billion tons of crude oil production,thus around 0.7% of crude oil is processed into PET.
Commentary published in Environmental Health Perspectives in April 2010 suggested that PET might yield endocrine disruptors under conditions of common use and recommended research on this topic. Proposed mechanisms include leaching of phthalates as well as leaching of antimony.An article published in Journal of Environmental Monitoring in April 201...
There are two basic molding methods for PET bottles, one-step and two-step. In two-step molding, two separate machines are used. The first machine injection molds the preform, which resembles a test tube, with the bottle-cap threads already molded into place. The body of the tube is significantly thicker, as it will be inflated into its final shape...
Worldwide, 480 billion plastic drinking bottles were made in 2016 (and less than half were recycled). While most thermoplastics can, in principle, be recycled, PET bottle recycling is more practical than many other plastic applications because of the high value of the resin and the almost exclusive use of PET for widely used water and carbonated so...
The Mount Edziza volcanic complex (MEVC) is a group of volcanoes and associated lava flows in northwest British Columbia, Canada. Located on the Tahltan Highland, the MEVC has a broad, steep-sided lava plateau; its highest summit is 2,786 metres (9,140 feet). Its volcanoes formed over the last 7.5 million years during five cycles of magmatic ...
Brad Pitt filmography. Brad Pitt (born December 18, 1963) is an American actor and producer. His acting career began at age 23 in 1987 with roles in the hit Fox television series 21 Jump Street. He subsequently appeared in episodes for television shows during the late 1980s and played his first major role in the slasher film Cutting Class (1989 ...
Michael Joseph Jackson (August 29, 1958 – June 25, 2009) was an American singer, songwriter, dancer, and philanthropist. Known as the "King of Pop", he is regarded as one of the most significant cultural figures of the 20th century. During his four-decade career, his contributions to music, dance, and fashion, along with his publicized ...
