Porcelain
The Shang dynasty began its rule in 1600 BCE, marking the start of centuries-long ceramic experimentation that would eventually yield true porcelain. Early glazed wares from this era evolved into what Chinese historians define as high-fired ware by the time of the Eastern Han dynasty between 25 and 220 CE. By the late Sui dynasty spanning 581 to 618 CE, artisans had achieved the standard requirements of whiteness and translucency seen in Ding ware types. The technology matured fully between approximately 200 and 800 CE, creating a material distinct from all previous pottery forms. These early pieces were already exported to the Islamic world where they held immense value. The dragon kilns excavated from the Song dynasty period could fire as many as 25,000 pieces at one time. Over 100,000 items could be produced by the end of that same historical period.
Raw materials generally include kaolinite heated in a kiln to temperatures between 1200 and 1400 degrees Celsius. The greater strength and translucence arise mainly from vitrification and the formation of the mineral mullite within the body at these high temperatures. Kaolin is the primary material even though clay minerals might account for only a small proportion of the whole mixture. Other raw materials can include feldspar, ball clay, glass, bone ash, steatite, quartz, petuntse and alabaster. Clays used are often described as being long or short depending on their plasticity. Long clays are cohesive and have high plasticity while short clays are less cohesive with lower plasticity. Small changes in water content produce large changes in workability because the range of water content is very narrow. This requires careful control during the forming process before firing begins.
Hard-paste porcelain was invented in China and later used in Japanese porcelain production. Most of the finest quality wares are made from this specific material type. Early European porcelains were produced at the Meissen factory in the early 18th century using a paste composed of kaolin and alabaster. These pieces were fired at temperatures up to 1450 degrees Celsius in wood-fired kilns producing great hardness and strength. Later compositions replaced alabaster with feldspar and quartz allowing pieces to be fired at lower temperatures. Soft-paste porcelins date back to early attempts by European potters using mixtures of clay and frit. Soapstone and lime were known to have been included in these compositions but they were not yet actual porcelain wares. As these early formulations suffered from high pyroplastic deformation they were uneconomic to produce and of low quality. Soft-paste porcelains are generally less hard than hard-paste varieties due to lower firing temperatures.
Ehrenfried Walther von Tschirnhaus produced a hard white translucent type of porcelain specimen in 1708 using ingredients mined from a Saxon mine in Colditz. Johann Friedrich Böttger had originally been trained as a pharmacist before turning to alchemical research claiming to know the secret of transmuting dross into gold. Augustus II King of Poland and Elector of Saxony imprisoned Böttger as an incentive to hasten his research on porcelain manufacture. A workshop note records that the first specimen of hard vitrified European porcelain was produced in 1708 though Tschirnhaus died shortly after. It was left to Böttger to report to Augustus in March 1709 that he could make porcelain successfully. The Meissen factory was established in 1710 after developing a kiln suitable for use with Böttger's porcelain requiring firing at temperatures up to 1450 degrees Celsius. A visitor reported seeing a white-hot teapot being removed from the kiln and dropped into cold water without damage.
Porcelain wares were exported to Asia Africa and Europe via the Silk Road during the Ming dynasty spanning 1368 to 1644 CE. In 1517 Portuguese merchants began direct trade by sea with the Ming dynasty while Dutch merchants followed in 1598. Imported Chinese porcelains were held in such great esteem in Europe that china became a commonly used synonym for porcelain in English. The first mention of porcelain in Europe appears in Il Milione by Marco Polo in the 13th century. Early in the 16th century Portuguese traders returned home with samples of kaolin which they discovered in China to be essential. Countless experiments to produce porcelain had unpredictable results and met with failure until secrets were revealed through Jesuit correspondence. François Xavier d'Entrecolles published elaborate Chinese manufacturing secrets throughout Europe in 1712 within letters republished by Jean-Baptiste Du Halde in 1735. These revelations allowed European factories to begin producing their own versions of the coveted material.
Porcelain has been used for electrical insulators since at least 1878 according to records from the Institution of Electrical Engineers. A body for electrical porcelain typically contains varying proportions of ball clay kaolin feldspar quartz calcined alumina and calcined bauxite. UK manufacturers typically fired the porcelain to a maximum of 1200 degrees Celsius in an oxidising atmosphere whereas reduction firing is standard practice at Chinese manufacturers. In 2018 a porcelain bushing insulator manufactured by NGK in Handa Japan was certified as the world's largest ceramic structure by Guinness World Records. It stands 11.3 meters in height and 1.5 meters in diameter. The global market for high-voltage insulators was estimated to be worth US$4.95 billion in 2015 with porcelain accounting for just over 48 percent. Porcelain tiles have been defined as dense fine-grained smooth ceramic mosaics usually impervious with clear luminous colors or granular blends thereof. Italy remains the global leader producing over 380 million square metres in 2006 alone.
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Common questions
When did the Shang dynasty begin its rule and start ceramic experimentation?
The Shang dynasty began its rule in 1600 BCE, marking the start of centuries-long ceramic experimentation that would eventually yield true porcelain. Early glazed wares from this era evolved into what Chinese historians define as high-fired ware by the time of the Eastern Han dynasty between 25 and 220 CE.
What raw materials are used to make porcelain and at what temperatures is it fired?
Raw materials generally include kaolinite heated in a kiln to temperatures between 1200 and 1400 degrees Celsius. The greater strength and translucence arise mainly from vitrification and the formation of the mineral mullite within the body at these high temperatures.
Who invented hard-paste porcelain and when was the Meissen factory established?
Hard-paste porcelain was invented in China and later used in Japanese porcelain production. The Meissen factory was established in 1710 after developing a kiln suitable for use with Böttger's porcelain requiring firing at temperatures up to 1450 degrees Celsius.
How were porcelain wares exported to Europe during the Ming dynasty?
Porcelain wares were exported to Asia Africa and Europe via the Silk Road during the Ming dynasty spanning 1368 to 1644 CE. In 1517 Portuguese merchants began direct trade by sea with the Ming dynasty while Dutch merchants followed in 1598.
When did porcelain begin being used as electrical insulators and what are its modern dimensions?
Porcelain has been used for electrical insulators since at least 1878 according to records from the Institution of Electrical Engineers. In 2018 a porcelain bushing insulator manufactured by NGK in Handa Japan was certified as the world's largest ceramic structure by Guinness World Records standing 11.3 meters in height and 1.5 meters in diameter.