Search results
Results from the WOW.Com Content Network
The defining mechanical property of clay is its plasticity when wet and its ability to harden when dried or fired. Clays show a broad range of water content within which they are highly plastic, from a minimum water content (called the plastic limit) where the clay is just moist enough to mould, to a maximum water content (called the liquid ...
All fired ceramic wares or materials which, when shaped, contain a significant amount of clay. Exceptions are those used for technical, structural or refractory applications. Pottery is also: (1) the art and wares made by potters; (2) a ceramic material (3) a place where pottery wares are made; and (4) the business of the potter.
Fire clay is a range of refractory clays used in the manufacture of ceramics, especially fire brick. The United States Environmental Protection Agency defines fire clay very generally as a "mineral aggregate composed of hydrous silicates of aluminium (Al 2 O 3 ·2SiO 2 ·2H 2 O) with or without free silica."
Clay tempered with sand, grit, crushed shell or crushed pottery were often used to make bonfire-fired ceramics because they provided an open-body texture that allowed water and volatile components of the clay to escape freely. The coarser particles in the clay also acted to restrain shrinkage during drying, and hence reduce the risk of cracking.
Key criteria are the composition of the clay and the temper used in the manufacture of the article under study: the temper is a material added to the clay during the initial production stage and is used to aid the subsequent drying process. Types of temper include shell pieces, granite fragments, and ground sherd pieces called 'grog'. Temper is ...
In the making of firebrick, fire clay is fired in the kiln until it is partly vitrified.For special purposes, the brick may also be glazed. There are two standard sizes of fire brick: 9 in × 4 + 1 ⁄ 2 in × 3 in (229 mm × 114 mm × 76 mm) and 9 in × 4 + 1 ⁄ 2 in × 2 + 1 ⁄ 2 in (229 mm × 114 mm × 64 mm). [2]
In the case of pottery, clay materials are shaped, dried and then fired in a kiln. The final characteristics are determined by the composition and preparation of the clay body and the temperature at which it is fired. After a first firing, glazes may be used and the ware is fired a second time to fuse the glaze into the body. A third firing at ...
Clay blocks (sometimes called clay block brick) being laid with an adhesive rather than mortar. Bricks are made in a similar way to mud-bricks except without the fibrous binder such as straw and are fired ("burned" in a brick clamp or kiln) after they have air-dried to permanently harden them. Kiln fired clay bricks are a ceramic material ...