Bone china is a kind of soft-paste porcelain consisting of bone ash, feldspathic material, and kaolin. It has been defined as ware with translucent body containing at least 30% phosphate derived from animal bones and calcium phosphate calculated. Bone china is the strongest of porcelain or china ceramics, has a very high mechanical strength and chip resistance, and is known for its high level of white and translucent. Its high strength allows it to be produced in thinner sections than other porcelain types. Such a pot is vitrification, but translucent because of the properties of different minerals.
The first developed porcelain bone was developed extensively by British Potera Josiah Spode in the early 1790s. From early development and to the end of the 20th century, bone china is almost exclusively an English product, with effectively localized production at Stoke-on-Trent. Most of the major UK companies are made or are still making it, including Fortnum & amp; Mason, Mintons, Coalport, Spode, Royal Crown Derby, Royal Doulton, Wedgwood and Worcester.
In the United Kingdom, references to "porcelain" or "porcelain" may refer to bone china, and "British porcelain" has been used as a term for it, both in England and around the world.
Video Bone china
Histori
The first development of what would be known as bone china was made by Thomas Frye at the Bow porcelain factory near Bow in East London in 1748. The factory is located very close to the cattle market and the slaughterhouse of Essex, and hence easy access to the animal bones. Frye uses up to 45% bone ash in his formulation to create what he calls "fine porcelain". Despite rivaling porcelain imported from Europe and China in quality, the plant was not commercially successful.
Then, Josiah Spode in Stoke-on-Trent developed the concept between 1789 and 1793, introducing "Stoke China" in 1796. He died suddenly a year later, and his son Josiah II quickly revived the "Bone china". Among its developments is abandoning Frye's procedure for calcining bone along with some other body raw materials, rather than just calcining bone. Bone china quickly proved very popular, leading to its production by other UK pottery manufacturers. Both the Spode formulation and the business succeeded: the formulation of 6 parts of the ash bone, 4 parts of china and 3.5 parts of clay china, remains the basis for all bone china, and it was only in 2009 that his company, Spode, went to the curator before finally bought by Portmeirion.
Maps Bone china
Production
The production of bone china is similar to porcelain, except that more care is needed because of lower plasticity and a narrower range of vitrification. The traditional formulation for bone china is about 25% kaolin, 25% Cornish stone and 50% bone ash. Bone ash used in bone china is made of cow bone which has a lower iron content. These bones are destroyed before being demolarized and then calcined up to 1250 ° C to produce bone ash. Ash is ground into fine particle size. The kaolin component of the body is required to provide untreated body plasticity that allows the goods to be formed. This mixture is then fired at around 1200 ° C. The raw material for bone china is relatively expensive, and its production is labor intensive, which is why bone china maintains its luxurious status and high price.
Bone china consists of two phases of crystals, anorthite (CaAl 2 Si 2 O 8 ) and? -tricalcium phosphate/whitlockite (Ca 3 (PO 4 ) 2 ) is embedded in a substantial amount of glass.
Production location
For nearly 200 years of china its development bone almost exclusively produced in England. During the middle of the 20th century producers in other countries started production, with the first successful outside Britain being in Japan: Noritake, Nikko, and Narumi.
In recent years, production in China has grown rapidly, and the country is now the world's largest producer of bone. Other countries producing large quantities of bone china are Bangladesh, India, Indonesia, Iran, Sri Lanka and Thailand.
From the start of the first plant, Bounty Potteries, in 1964, bone china production from factories in India has increased to 10,000 tonnes per year in 2009. Rajasthan has become a center for bone china in India, with 16- 17 tons per day.
Lenox is the only major bone china producer in the United States, and has supplied presidential services to the White House.
Cultural issues
Because of the use of animal bones in certain bone porcelain production, some vegetarians and vegans avoid using or buying them.
See also
- Hard porcelain portions
References
External links
- Media related to Bone china in Wikimedia Commons
Source of the article : Wikipedia
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