Frit porcelain

from Wikipedia, the free encyclopedia
İznik ceramics , style: “ saz and rosette ”
Collection: British Museum
Example: for frit porcelain

Frit porcelain ( French porcelaine tendre , English fritware ) is a semi, pseudo or fake porcelain . It was mostly made in 18th century France. The production method was evidently developed from glass technology by using the process of fritting, i.e. the production of a sintered or premelted granular raw product. White opacifiers were added to this crude product, as were customary in glass melting and faience glazes. In the classic composition, frit porcelain does not contain kaolin , which is an essential difference to real porcelain.

Specification according to the classification of ceramic bodies
Class:

Earthenware

Subclass:

Other earthenware

Group:

Crockery

Subgroup:

glazed

Frit porcelain also chips

Demarcation

A different assignment to soft porcelain is not correct because it cannot be assigned to the sintered product after its composition and manufacture . This is why this special ceramic is more appropriately referred to as fritware in the English-speaking area and moved into the neighborhood of stonepaste , pottery or fayance, i.e. clearly differentiated from china .

A reason for the ambiguous naming can also be found in the manufacturers' need for recognition. Since the production of the frit porcelain falls in the early phase of the European efforts for the "white gold", it promised higher prestige to be able to lay claim to the oldest production process. French frit porcelain manufacturers like the Manufacture royale de porcelaine de Sèvres avoided clear boundaries.

Manufacturing

Fries for the ceramic glaze

The production of frit porcelain is lengthy and complicated, so it was considerably more expensive than porcelain. First, quartz sand , saltpeter , table salt , soda , alum and calcium sulfate (in the form of alabaster or plaster of paris ) were mixed and fired until a glassy substance - the frit - was created. This material was broken up and ground up and then mixed with marl containing chalk or gypsum in a 3: 1 ratio. Green soap was also added to the mixture to increase the malleability of the mass. After a laborious release of air bubbles by kneading and rolling, the mass was shaped, glazed and fired to the end product.

properties

Frit porcelain is more sensitive to temperature fluctuations and more sensitive to shock. The glaze is also softer and can be damaged with cutlery, for example. However, it also has a higher refraction, which increases the luminosity of the colors. On top of that, frit porcelain is fired at lower temperatures, which means that a wider range of colors can be used. Since it becomes softer, “more fluid” during firing, no overly complicated figures could be created in it.

Manufactories

The following French manufacturers, for example, produced frit porcelain:

See also

literature

  • Gustav Weiß: Ullstein porcelain book. A history of style and technology of porcelain with a list of brands . Ullstein, Berlin a. a. 1964, p. 58 u. 63.
  • Sven Frotscher: dtv - Atlas ceramics and porcelain. dtv Verlag 2003. ISBN 3-423-03258-8 .

Web links