Pottery is the ceramic A ceramic is an inorganic, non-metallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous . Because most common ceramics are crystalline, the definition of ceramic is often restricted to inorganic crystalline materials, as opposed to the non- ware made by potters.[1] The place where such wares are made is also called a pottery (plural potteries).[2] Pottery can also refer to the material of which the potteryware is made.[3][4] Major types of pottery include earthenware Earthenware is a common ceramic material, which is used extensively for pottery tableware and decorative objects. Although body formulations vary between countries and even between individual makers, a generic composition is 25% ball clay, 28% kaolin, 32% quartz, and 15% feldspar. Earthenware is one of the oldest materials used in pottery. While, stoneware "Stoneware, which, though dense, impermeable and hard enough to resist scratching by a steel point, differs from porcelain because it is more opaque, and normally only partially vitrified. It may be vitreous or semi-vitreous. It is usually coloured grey or brownish because of impurities in the clay used for its manufacture, and is normally and porcelain Porcelain is a ceramic material made by heating raw materials, generally including clay in the form of kaolin, in a kiln to temperatures between 1,200 °C and 1,400 °C (2,552 °F). The toughness, strength, and translucence of porcelain arise mainly from the formation of glass and the mineral mullite within the fired body at these high. Pottery is one of the oldest human technologies and art-forms, and remains a major industry today. The definition used by archaeologists tends to exclude ceramic objects such as figurines which are made by similar processes, and perhaps the same people, but are not vessels, or made on a potter's wheel In pottery, a potter's wheel is a machine used in the shaping of round ceramic wares. The wheel may also be used during the process of trimming excess body from dried wares and for applying incised decoration or rings of color. Use of the potter's wheel became widespread throughout the Old World but was unknown in the Pre-Columbian New World,.
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Background
Pottery is made by forming a clay body Historically the production of pottery has been a characteristic of human activity in most areas of the world. Over time, each culture has established terms which define tools, ingredients and production techniques. Terms currently in use may be derived from a variety of pottery traditions into objects of a required shape and heating them to high temperatures in a kiln Kilns are an essential part of the manufacture of all ceramics, which, by definition, require heat treatment, often at high temperature. During this process, chemical and physical reactions occur which cause the material to be permanently altered. In the case of pottery, clay materials are shaped, dried and then fired in a kiln. The final to induce reactions that lead to permanent changes, including increasing their strength and hardening and setting their shape. There are wide regional variations in the properties of raw materials used for the production of pottery, and this can lead to wares that are unique in character to a locality. It is common for clays and other materials to be mixed to produce clay bodies suited to specific purposes.
Prior to some shaping processes, 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 Historically the production of pottery has been a characteristic of human activity in most areas of the world. Over time, each culture has established terms which define tools, ingredients and production techniques. Terms currently in use may be derived from a variety of pottery traditions. Wedging can also help to ensure an even moisture content throughout the body. Once a clay body has been de-aired or wedged, it is shaped by a variety of techniques. After shaping it is dried before firing. There are a number of stages in the drying process. Leather-hard refers to the stage when the clay object is approximately 15% mositure content. Clay bodies at this stage are very firm and only slightly pliable. Trimming and handle attachment often occurs at the leather-hard state. Clay bodies are said to be "bone-dry" when they reach a moisture content at or near 0%. Unfired objects are often termed greenware. Clay bodies at this stage are very fragile and hence can be easily broken.
Methods of shaping
A man shapes pottery as it turns on a wheel. (Cappadocia Cappadocia is a region in central Turkey, largely in Nevşehir Province, Turkey Turkey , known officially as the Republic of Turkey ( Türkiye Cumhuriyeti (help·info)), is a Eurasian country that stretches across the Anatolian peninsula in western Asia and Thrace (Rumelia) in the Balkan region of southeastern Europe. Turkey is one of the six independent Turkic states. Turkey is bordered by eight countries: Bulgaria to the).Pottery can be shaped by a range of methods that include:
Handwork pottery in Kathmandu Kathmandu is the capital and largest metropolitan city of Nepal. The city is the urban core of the Kathmandu Valley in the Himalayas, which also contains two sister cities namely Patan or Lalitpur, 5 kilometres (3.1 mi) to its southeast (an ancient city of fine arts and crafts) and Bhaktapur, 14 kilometres (8.7 mi) to its east (city of devotees), Nepal Nepal (pronounced /nəˈpal/ nə-PAHL, /-pal/ -PAWL; Nepali: नेपाल [neˈpal] ), officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India. With an area of 1.Hand building. This is the earliest forming method. Wares can be constructed by hand from coils of clay, from flat slabs of clay, from solid balls of clay, or some combination of these. Parts of hand-built vessels are often joined together with the aid of slip A slip is a suspension in water of clay and/or other materials used in the production of ceramic ware. Deflocculant, such as sodium silicate, can be added to the slip to disperse the raw material particles. This allows a higher solids content to be used, or allows a fluid slip to be produced with the a minimum of water so that drying shrinkage is, an aqueous suspension of clay body and water. Hand building is slower than wheel-throwing, but it offers the potter a high degree of control over the size and shape of wares. The speed and repetitiveness of other techniques is more suitable for making precisely matched sets of wares such as tablewares Tableware or Table Appointments includes the dishes, sauce boats, glassware, and cutlerys used to set a table for eating a meal. The nature, variety, and number of objects varies from culture to culture, and may vary from meal to meal, although some studio potters Studio pottery is made by modern artists working alone or in small groups, producing unique items or pottery in small quantities, typically with all stages of manufacture carried out by one individual. Much studio pottery is table ware or cook ware but an increasing number of studio potters produce non-functional or sculptural items. Since the 1980 find hand building more conducive to create one-of-a-kind works of art Art is the product or process of deliberately arranging symbolic elements in a way that influences and affects the senses, emotions, and/or intellect. It encompasses a diverse range of human activities, creations, and modes of expression, including music, literature, film, photography, sculpture, and paintings. The meaning of art is explored in a.
A potter shapes a piece of pottery on an electric-powered potter's wheel Classic potter's kick wheel in Erfurt Erfurt is the capital city of Thuringia and is the main city nearest to the geographical centre of Germany, located 100 km SW of Leipzig, 150 km N of Nürnberg and 180 km SE of Hannover. Erfurt Airport can be reached by plane via Munich. It lies in the southern part of the Thuringian Basin, within the wide valley of Gera River, a tributary of the, Germany A region named Germania, inhabited by several Germanic peoples, has been known and documented before AD 100. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire, which lasted until 1806. During the 16th century, northern Germany became the centre of the Protestant Reformation. As a modern nation-state,The potter's wheel In pottery, a potter's wheel is a machine used in the shaping of round ceramic wares. The wheel may also be used during the process of trimming excess body from dried wares and for applying incised decoration or rings of color. Use of the potter's wheel became widespread throughout the Old World but was unknown in the Pre-Columbian New World,. In the process that called "throwing" (coming from the Old English Old English or Anglo-Saxon is an early form of the English language that was spoken and written by the Anglo-Saxons and their descendants in parts of what are now England and south-eastern Scotland between at least the mid-5th century and the mid-12th century. What survives through writing represents primarily the literary register of Anglo-Saxon word thrawan, which means to twist or turn[5]), a ball of clay is placed in the center of a turntable, called the wheel-head, which the potter rotates with a stick, with foot power or with a variable speed electric motor An electric motor uses electrical energy to produce mechanical energy, very typically through the interaction of magnetic fields and current-carrying conductors. The reverse process, producing electrical energy from mechanical energy, is accomplished by a generator or dynamo. Many types of electric motors can be run as generators, and vice versa.
During the process of throwing the wheel rotates rapidly while the solid ball of soft clay is pressed, squeezed and pulled gently upwards and outwards into a hollow shape. The first step of pressing the rough ball of clay downward and inward into perfect rotational symmetry Generally speaking, an object with rotational symmetry is an object that looks the same after a certain amount of rotation. An object may have more than one rotational symmetry; for instance, if reflections or turning it over are not counted, the triskelion appearing on the Isle of Man's flag has three rotational symmetries (or "a threefold, is called centering the clay, a most important skill to master before the next steps: opening (making a centered hollow into the solid ball of clay), flooring (making the flat or rounded bottom inside the pot), throwing or pulling (drawing up and shaping the walls to an even thickness), and trimming or turning (removing excess clay to refine the shape or to create a foot).
Considerable skill and experience are required to throw pots of an acceptable standard, and whilst the ware may have high artisitic merit the reproducibility of the method is poor[6]. Because of its inherent limitations, throwing can only be used to create wares with radial symmetry Symmetry in biology is the balanced distribution of duplicate body parts or shapes. The body plans of most multicellular organisms exhibit some form of symmetry, either radial symmetry or bilateral symmetry or "spherical symmetry". A small minority exhibit no symmetry on a vertical axis A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length. These can then be altered by impressing, bulging, carving, fluting, and incising In geomorphology, the term Incised refers to when a river has cut downward through its riverbed. The river may have been incising through sediment or bedrock. The river begins at one elevation and incises downward through its bed while leaving its floodplain behind . Although, it is possible for the floodplain to be lowered at the same time. In addition to the potter's hands these techniques can use tools, including paddles, anvils & ribs, and those specifically for cutting or piercing such as knives, fluting tools & wires. Thrown pieces can be further modified by the attachment of handles, lids, feet and spouts.
Granulate pressing: As the name suggests, this is the operation of shaping pottery by pressing clay in a semi-dry and granulated condition in a mould A mold or mould is a hollowed-out block that is filled with a liquid like plastic, glass, metal, or ceramic raw materials. The liquid hardens or sets inside the mold, adopting its shape. A mold is the opposite of a cast. The manufacturer who makes the molds is called the moldmaker. A release agent is typically used to make removal of the hardened/. The clay is pressed into the mould by a porous die through which water is pumped at high pressure. The granulated A granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact . The constituents that compose granular material must be large enough such that they are not subject to thermal motion fluctuations. Thus, the lower size limit for grains in granular material is about 1 clay is prepared by spray-drying to produce a fine and free flowing material having a moisture content of between about five and six per cent. Granulate pressing, also known as dust pressing, is widely used in the manufacture of ceramic tiles A tile is a manufactured piece of hard-wearing material such as ceramic, stone, metal, or even glass. Tiles are generally used for covering roofs, floors, and walls, showers, or other objects such as tabletops. Alternatively, tile can sometimes refer to similar units made from lightweight materials such as perlite, wood, and mineral wool, and, increasingly, of plates.
Injection Moulding Injection molding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Material is fed into a heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the configuration of the mold cavity. After a product is designed, usually by an industrial designer or an engineer,: is a shape forming process adapted for the tableware industry from the method long established for the forming of thermoplastic A thermoplastic, also known as thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently. Most thermoplastics are high-molecular-weight polymers whose chains associate through weak Van der Waals forces ; stronger dipole-dipole interactions and hydrogen bonding (nylon); or and some metal components.[7] It has been called Porcelain Injection Moulding, or PIM.[8] Suited to the mass production of complex-shaped articles one significant advantage of the technique is that it allows the production of a cup A teacup is a small cup, with or without a handle, generally a small one that may be grasped with the thumb and one or two fingers. It is typically made of a ceramic material. It is usually part of a set, composed of a cup and a matching saucer. These in turn may be part of a tea set in combination with a teapot, cream jug, covered sugar bowl and including the handle in a single process, and thereby eliminating the handle fixing operation and producing a stronger bond between cup and handle.[9] The feed to the mould die is a mix of approximately 50 - 60% unfired body, in powder form, together with 40 - 50 % organic additives composed of binders A binder is an ingredient used to bind together two or more other materials in mixtures. Its two principal properties are adhesion and cohesion, lubricants and plasticisers Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effect is slightly different. The worldwide market for plasticizers in 2004.[10] The technique is not as widely used as other shaping methods.[11]
Jiggering and jolleying Historically the production of pottery has been a characteristic of human activity in most areas of the world. Over time, each culture has established terms which define tools, ingredients and production techniques. Terms currently in use may be derived from a variety of pottery traditions: These operations are carried out on the potter's wheel and allow the time taken to bring wares to a standardized form to be reduced. Jiggering is the operation of bringing a shaped tool into contact with the plastic clay of a piece under construction, the piece itself being set on a rotating plaster mould on the wheel. The jigger tool shapes one face whilst the mould shapes the other. Jiggering is used only in the production of flat wares, such as plates, but a similar operation, jolleying, is used in the production of hollow-wares, such as cups. Jiggering and jolleying have been used in the production of pottery since at least the 18th century. In large-scale factory production jiggering and jolleying are usually automated, which allows the operations to be carried out by semi-skilled labor.
Shaping on a potter's kick wheel; Gülşehir Gülşehir, formerly Arapsun, ancient Zoropassos, is a town and district of Nevşehir Province in the Central Anatolia region of Turkey, in the vicinity of the Fairy Chimney valley of Göreme. According to 2000 census, population of the district is 31,664 of which 9,377 live in the town of Gülşehir, and the remainder in surrounding villages. The, TurkeyRoller-head machine Historically the production of pottery has been a characteristic of human activity in most areas of the world. Over time, each culture has established terms which define tools, ingredients and production techniques. Terms currently in use may be derived from a variety of pottery traditions: This machine is for shaping wares on a rotating mould, as in jiggering and jolleying, but with a rotary shaping tool replacing the fixed profile. The rotary shaping tool is a shallow cone having the same diameter as the ware being formed and shaped to the desired form of the back of the article being made. Wares may in this way be shaped, using relatively unskilled labor, in one operation at a rate of about twelve pieces per minute, though this varies with the size of the articles being produced. Developed in the UK just after World War II by the company Service Engineers roller-heads were quickly adopted by manufacturers around the world; they remain the dominant method for producing flatware.[12]
Pressure casting - specially developed polymeric materials allows mould to be subject to application external pressures of up to 4.0 MPa, and so much higher than slip casting in plaster moulds where the capillary forces correspond to a pressure of around 0.1 - 0.2 MPa. The high pressure leads to much faster casting rates, and hence faster production cycles. Furthermore the application of high pressure air through the polymeric moulds upon demoulding the cast means a new casting cycle can be started immediately in the same mould, unlike plaster moulds which require lengthy drying times. The polymeric materials have much greater durability than plaster and, therefore, it is possible to achieve shaped products with better dimensional tolerances and much longer mould life. Pressure casting was developed in the 1970s for the production of sanitaryware, although more recently it has been applied to tableware.[13][14][15][16]
RAM pressing A RAM press is a machine, invented in the USA in the mid-1940s, that is used to press clay into moulded shapes, such as plates and bowls. In operation a slice of de-aired clay body is placed in between two shaped porous moulds, and vertical movement of the moulds presses the body into the required shape: A factory process for shaping table wares and decorative ware by pressing a bat of prepared clay body into a required shape between two porous molding plates. After pressing, compressed air is blown through the porous mould plates to release the shaped wares.
Slipcasting Slipcasting is a technique for the mass-production of pottery, especially for shapes not easily made on a wheel. A liquid clay body slip is poured into plaster moulds and allowed to form a layer, the cast, on the inside cavity of the mould. In a solid cast mould, ceramic objects such as handles and platters are surrounded by plaster on all sides: is often used in the mass-production of ceramics and is ideally suited to the making of wares that cannot be formed by other methods of shaping. A slip A slip is a suspension in water of clay and/or other materials used in the production of ceramic ware. Deflocculant, such as sodium silicate, can be added to the slip to disperse the raw material particles. This allows a higher solids content to be used, or allows a fluid slip to be produced with the a minimum of water so that drying shrinkage is, made by mixing clay Clay is a naturally occurring material composed primarily of fine-grained minerals. Clay deposits are mostly composed of clay minerals, a subtype of phyllosilicate minerals, which impart plasticity and harden when fired or dried; they also may contain variable amounts of water trapped in the mineral structure by polar attraction. Organic materials body with water, is poured into a highly absorbent plaster mold. Water from the slip is absorbed into the mould leaving a layer of clay body covering its internal surfaces and taking its internal shape. Excess slip is poured out of the mold, which is then split open and the molded object removed. Slipcasting is widely used in the production of sanitary wares and is also used for making smaller articles, such as intricately detailed figurines.
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auction to mark 15 years Richmond County Daily Journal Several supporters of the FirstHealth Hospice Foundation consider a bid for the silent auction portion of the 2009 Pottery Plus Auction. ...
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Some native american indian textiles show very Western geometric forms such as rectangles triangles parallelograms circles and trapezoids Their pottery also includes some of these shapes Images from R B Ravens
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www.arttvllc.com HDTV documentary for WETA aired nationally on PBS taped in New Mexico and the National Museum of Women in the ARts. Features the ... youtube.com.
