Claudia Eisermann1 Earthenware, pottery, porcelain, ceramics - which ingredients are needed to allow molding and what happens during burning ?

Claudia Eisermann2 Contents: Overall view Pottery Porcelain Ceramics Which ingredients allow molding ? Burning

Claudia Eisermann3 Overall view Earthenware: - used for pottery - made from clay - slightly porous after first firing (not vitrified) - glaze before second firing -> waterproof

Claudia Eisermann4 Overall view Porcelain: - made from mixture of kaolin and petuntse - differences to stoneware less clear - pottery, resonant against pushes - vitrified pottery

Claudia Eisermann5 Overall view Ceramics: - differences to porcelain in roughness and stability - important material: clay - depending on use high quality claim - able to produce wanted color (porcelain too)

Claudia Eisermann6 Pottery History: - before Christ: vessel - 15th century: decoration; first mould - 18th century: moulds of plaster - 19th century: mechanization (England) Important ages: - ancient world, renaissance (Donatello, Luca della Robbia)

Claudia Eisermann7 Pottery Production: - red clay (Fe) or yellow clay (lime) - clay dug out, dried, ground - water added, mixed 1) moulds: equal layer -> plaster takes water -> pottery shrinks -> precision work 2) handwork: forming with hands, wet cloth, wooden spatula, slow drying before burning

Claudia Eisermann8 Pottery Burning: - dry products (water evaporates ->cracks) °C, 5 – 10 days - slow cool down - to high temperature -> vitrification - to low temperature -> porous - pottery in cool water -> lime extinguished -> pores density increases

Claudia Eisermann9 Pottery Properties: - easy to form - natural warm color - long durable - water-resistant - resistant against frost (high density -> less water taken up -> small expansion)

Claudia Eisermann10 Pottery Use: - vessels, statues of animals - oil lamps - art, decoration, jewelry - building materials and commercial materials: tiles, plates for covering, washbasin, vases, pots

Claudia Eisermann11 Porcelain called “white gold” noble products are hard porcelain and Bone China (made with ash of bones; England) famous factories: Meißen, Fürstenberg, Frankenthal

Claudia Eisermann12 Porcelain History: - developed in year 620 in China in Europe, by Ehrenfried Walther von Tschirnhaus - continued by Johann Friedrich Böttger , Meißen: first manufacture in Europe (which became famous in the world)

Claudia Eisermann13 Porcelain Hard porcelain: - Kaolin (50%), feldspar (25%), quartz (25%) - third burning temperature: 1410 °C Soft porcelain: - Kaolin (40%), feldspar (30%), quartz (30%) - third burning temperature: 1300 °C

Claudia Eisermann14 Porcelain Production: - mixture of 3 materials - forming by hand (spinning slice) or by machines (pressure) - first firing (850 – 950 °C), cool down (slow) - second firing (1300 – 1410 °C) - glaze applied - painting + glaze - third firing (780 – 1410 °C, depending on glaze)

Claudia Eisermann15 Porcelain Forming by hand: - compact mass - pliable Foundry: - liquid mixture - hollow products (solid edge -> liquid rest decanted)

Claudia Eisermann16 Porcelain Properties: - thick fragments - shell-shaped break - high roughness - constant against acids and lye - bright sound - constant against high temperatures - isolation against electricity

Claudia Eisermann17 Porcelain Use: - decoration - isolator - dishes - chemical device (crucible)

Claudia Eisermann18 Ceramics History: - before Christ: rotating potter´s wheel in China - 16th century: fly wheel - 19th century: pedal -> two free hands - 20th century: electric motor (regular speed)

Claudia Eisermann19 Ceramics Production: - clay, water - mixture cast/formed/pressed - burning (600 °C) -> moisture removed - 2nd burning -> smooth surface - decoration (stamp, carving, cut parts out) - glaze

Claudia Eisermann20 Ceramics Properties: - high roughness - resistant against weather - bears high temperatures - electrical isolation - very low wear - dimensional stability - adapted to the use (raw materials, production) - different colors

Claudia Eisermann21 Ceramics Use: - mechanical engineering, process engineering - electronics - high temperature technique - building materials: tiles, plates - sanitary, appliances in the household (dishes) - pots

Claudia Eisermann22 High-performance ceramic since 1960 properties depend on use efficient example: dental ceramic - 1st burning: 1100 °C - 2nd burning: 1700 °C

Claudia Eisermann23 ingredients bigger than product (water evaporate) chamotte -> little loss organic additives: deflocculant, binding agent 1st burning -> additives removed green body (formed, not burned)

Claudia Eisermann24 Burning raw material compacted, less porous adapted temperature, pressure, time carbon built in the material -> stable coking (about 1000 °C) -> organic additives turn to carbon

Claudia Eisermann25 Burning clay + silicic acid -> Silimanit (Al 2 O 3 *SiO 2 ), Mullit (3 Al 2 O 3 *2 SiO 2 ) = double chains of silicate

Claudia Eisermann26 research/development improve specifications resistant against acid corrosion protection electrical isolation ceramic industry connected with chemistry

Claudia Eisermann27 sources Hollemann, Wiberg; Lehrbuch der anorganischen Chemie, de Gruyter,