7/27/2019 Definition of Term Porcelain

1/2

DEFINITION OF TERMS

Bisque-firing - After being formed, the porcelain parts are generally bisque-fired, which entails

heating them at a relatively low temperature to vaporize volatile contaminants and minimize

shrinkage during firing.

Bone China - Stronger than hard-paste porcelain and easier to manufacture. Its ivory white

appearance is created by adding bone ash to the ingredients for hard-paste porcelain.

Calcined bone ash - is used in the production of bone china and makes up about 50% by weight

of the final body recipe. It is produced from animal bone, which is first processed to remove any

adhering meat which is generally sold as pet food.

Clay - a stiff, sticky fine-grained impermeable earth that can be moulded when wet and baked

to make bricks and pottery.

Feldspar - an abundant rock-forming aluminosilicate mineral, typically colourless or pale-

coloured.

Firing - is a further heating step that can be done in one of two types of oven, or kiln. A periodic

kiln consists of a single, refractory-lined, sealed chamber with burner ports and flues (or electric

heating elements).

Fluxes - reduce the temperature at which liquid glass forms during firing to between 1,835 and

2,375 degrees Fahrenheit (1,000 and 1,300 degrees Celsius).

Glaze - is a layer of decorative glass applied to and fired onto a ceramic body.

Hard Paste Porcelain - Hard-paste porcelain is made from a mixture ofchina clay(kaolin)

and china stone (petuntse). The use of china stone dispenses with the need for the 'frit' used in

soft-paste porcelain. The strength and whiteness of the porcelain was improved by ageing the

paste in store.

Kiln - The final manufacturing phase is firing, a heating step that takes place in a type of oven.

Porcelain - is a ceramic material made by heating raw materials, generally including clay in the

form ofkaolin, in a kiln to temperatures between 1,200 C (2,192 F) and 1,400 C (2,552 F).

http://www.thepotteries.org/types/chinaclay.htmhttp://www.thepotteries.org/types/chinastone.htmhttp://www.thepotteries.org/types/frit.htmhttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Clayhttp://en.wikipedia.org/wiki/Kaolinhttp://en.wikipedia.org/wiki/Kilnhttp://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Fahrenheithttp://en.wikipedia.org/wiki/Fahrenheithttp://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Kilnhttp://en.wikipedia.org/wiki/Kaolinhttp://en.wikipedia.org/wiki/Clayhttp://en.wikipedia.org/wiki/Ceramichttp://www.thepotteries.org/types/frit.htmhttp://www.thepotteries.org/types/chinastone.htmhttp://www.thepotteries.org/types/chinaclay.htm

7/27/2019 Definition of Term Porcelain

2/2

The toughness, strength, and translucence of porcelain arise mainly from the formation

ofglass and the mineral mullite within the fired body at these high temperatures.

Pressing -This is used to compact and shape dry bodies in a rigid die or flexible mold.

Silica - silicon dioxide, a hard, unreactive, colourless compound which occurs as quartz and as

the principal constituent of sandstone and other rocks.

Slip Casting - in which slurry is poured into a porous mold. The liquid is filtered out through the

mold, leaving a layer of solid porcelain body.

Soft Paste Porcelain - First produced in Europe in 1738.Soft-paste porcelain is produced by

mixing white clay with 'frit' - a glassy substance that was a mixture of white sand, gypsum, soda,

salt, alum and nitre. Lime and chalk were used to fuse the white clay and the frit, the mixture is

then fired at a lower temperature than hard-paste porcelain.

Soft Plastic Forming - , where the clay is shaped by manual molding, wheel throwing, jiggering,

or ram is pressing.

Stiff Plastic Forming - This is used to shape less plastic bodies.

http://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Mullitehttp://www.thepotteries.org/types/frit.htmhttp://www.thepotteries.org/types/frit.htmhttp://en.wikipedia.org/wiki/Mullitehttp://en.wikipedia.org/wiki/Glass