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Pottery is the ceramic material which makes up potterywares,〔'Pottery Science: materials, process and products.' Allen Dinsdale. Ellis Horwood Limited, 1986.〕 of which major types include earthenware, stoneware and porcelain. The place where such wares are made is also called a ''pottery'' (plural "potteries"). Pottery also refers to the art or craft of a potter or the manufacture of pottery.〔'An Introduction To The Technology Of Pottery. 2nd edition. Paul Rado. Institute Of Ceramics & Pergamon Press, 1988〕 A dictionary definition is simply objects of fired clays.〔(Pottery, meaning 3, mass noun ), Oxford English Dictionary, Oxford University Press, 2015〕 The definition of ''pottery'' used by the American Society for Testing and Materials (ASTM) is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products."〔'Standard Terminology Of Ceramic Whitewares And Related Products.' ASTM C 242–01 (2007.) ''ASTM International''.〕 Pottery originated before the Neolithic period, with ceramic objects like the Gravettian culture Venus of Dolní Věstonice figurine discovered in the Czech Republic date back to 29,000–25,000 BC,〔 and pottery vessels that were discovered in Jiangxi, China, which date back to 20,000 BC.〔 Early Neolithic pottery have been found in places such as Jomon Japan (10,500 BC),〔 the Russian Far East (14,000 BC),〔 Sub-Saharan Africa and South America. Pottery is made by forming a clay body into objects of a required shape and heating them to high temperatures in a kiln which removes all the water from the clay, which induces reactions that lead to permanent changes including increasing their strength and hardening and setting their shape. A clay body can be decorated before or after firing. Prior to some shaping processes, clay must be prepared. Kneading helps to ensure an even moisture content throughout the body. Air trapped within the clay body needs to be removed. This is called de-airing and can be accomplished by a machine called a vacuum pug or manually by wedging. Wedging can also help produce an even moisture content. Once a clay body has been kneaded and de-aired or wedged, it is shaped by a variety of techniques. After shaping it is dried and then fired. ==Production stages== Clay ware takes on varying physical characteristics during the making of pottery. * Greenware refers to unfired objects. At sufficient moisture content, bodies at this stage are in their most plastic form (they are soft and malleable, and hence can be easily deformed by handling). * Leather-hard refers to a clay body that has been dried partially. At this stage the clay object has approximately 15% moisture content. Clay bodies at this stage are very firm and only slightly pliable. Trimming and handle attachment often occurs at the leather-hard state. * Bone-dry refers to clay bodies when they reach a moisture content at or near 0%. It is now ready to be bisque fired. * Bisque 〔"The Fast Firing Of Biscuit Earthenware Hollow-Ware In a Single-Layer Tunnel Kiln." Salt D.L. Holmes W.H RP737. ''Ceram Research''.〕〔"New And Latest Biscuit Firing Technology". Porzellanfabriken Christian Seltmann GmbH. ''Ceram.Forum Int.''/Ber.DKG 87,No.1/2, p.E33-E34,E36. 2010〕 refers to the clay after the object is shaped to the desired form and fired in the kiln for the first time, known as "bisque fired" or "biscuit fired". This firing changes the clay body in several ways. Mineral components of the clay body will undergo chemical changes that will change the colour of the clay. * Glaze fired is the final stage of some pottery making. A glaze may be applied to the bisque form and the object can be decorated in several ways. After this the object is "glazed fired", which causes the glaze material to melt, then adhere to the object. The glaze firing will also harden the body still more as chemical processes can continue to occur in the body. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pottery is the ceramic material which makes up potterywares,'Pottery Science: materials, process and products.' Allen Dinsdale. Ellis Horwood Limited, 1986. of which major types include earthenware, stoneware and porcelain. The place where such wares are made is also called a ''pottery'' (plural "potteries"). Pottery also refers to the art or craft of a potter or the manufacture of pottery.'An Introduction To The Technology Of Pottery. 2nd edition. Paul Rado. Institute Of Ceramics & Pergamon Press, 1988 A dictionary definition is simply objects of fired clays.(Pottery, meaning 3, mass noun ), Oxford English Dictionary, Oxford University Press, 2015 The definition of ''pottery'' used by the American Society for Testing and Materials (ASTM) is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products."'Standard Terminology Of Ceramic Whitewares And Related Products.' ASTM C 242–01 (2007.) ''ASTM International''.Pottery originated before the Neolithic period, with ceramic objects like the Gravettian culture Venus of Dolní Věstonice figurine discovered in the Czech Republic date back to 29,000–25,000 BC, and pottery vessels that were discovered in Jiangxi, China, which date back to 20,000 BC. Early Neolithic pottery have been found in places such as Jomon Japan (10,500 BC), the Russian Far East (14,000 BC), Sub-Saharan Africa and South America.Pottery is made by forming a clay body into objects of a required shape and heating them to high temperatures in a kiln which removes all the water from the clay, which induces reactions that lead to permanent changes including increasing their strength and hardening and setting their shape. A clay body can be decorated before or after firing. Prior to some shaping processes, clay must be prepared. Kneading helps to ensure an even moisture content throughout the body. Air trapped within the clay body needs to be removed. This is called de-airing and can be accomplished by a machine called a vacuum pug or manually by wedging. Wedging can also help produce an even moisture content. Once a clay body has been kneaded and de-aired or wedged, it is shaped by a variety of techniques. After shaping it is dried and then fired.==Production stages==Clay ware takes on varying physical characteristics during the making of pottery. * Greenware refers to unfired objects. At sufficient moisture content, bodies at this stage are in their most plastic form (they are soft and malleable, and hence can be easily deformed by handling).* Leather-hard refers to a clay body that has been dried partially. At this stage the clay object has approximately 15% moisture content. Clay bodies at this stage are very firm and only slightly pliable. Trimming and handle attachment often occurs at the leather-hard state.* Bone-dry refers to clay bodies when they reach a moisture content at or near 0%. It is now ready to be bisque fired.* Bisque "The Fast Firing Of Biscuit Earthenware Hollow-Ware In a Single-Layer Tunnel Kiln." Salt D.L. Holmes W.H RP737. ''Ceram Research''."New And Latest Biscuit Firing Technology". Porzellanfabriken Christian Seltmann GmbH. ''Ceram.Forum Int.''/Ber.DKG 87,No.1/2, p.E33-E34,E36. 2010 refers to the clay after the object is shaped to the desired form and fired in the kiln for the first time, known as "bisque fired" or "biscuit fired". This firing changes the clay body in several ways. Mineral components of the clay body will undergo chemical changes that will change the colour of the clay.* Glaze fired is the final stage of some pottery making. A glaze may be applied to the bisque form and the object can be decorated in several ways. After this the object is "glazed fired", which causes the glaze material to melt, then adhere to the object. The glaze firing will also harden the body still more as chemical processes can continue to occur in the body.」の詳細全文を読む スポンサード リンク
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