All about porcelain. Types of porcelain in dishes (classification, properties, appearance)

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sugar bowl, hard porcelain, Herend, decor "classic Victoria"

Depending on the composition of the mass and the firing temperature, there are ( which is fired at a temperature of 1350-1500 ° C) and ( fired at 1350°C).

Unlike from soft contains more kaolin - up to 36% or less feldspar- up to 28%.

This type of porcelain is called hard, because it is this quality that distinguishes it - hardness. It is opaque and heat resistant. When tapped, it gives a clear, ringing deep sound.

hard porcelain- this is a homogeneous, white mass, conchoidal and fine-grained in the fault. It consists of two main components - and feldspar. - pure clay, fusible, greasy and very plastic.

hard porcelain depends on the proportion of kaolin and feldspar. The more kaolin in the mass, the more difficult it is to melt and the harder the product is obtained.

butter dish, hard porcelain, Herend, decor "classic Victoria"

The resulting mass hard porcelain kneaded, subjected to fine grinding and dried to a plastic pasty state.

Finished objects are fired twice: first without glaze (at a temperature of 600-800 degrees C), then with glaze (at 1500 degrees C). Feldspar or pegmatite are used as fluxes.

Sometimes, to enhance translucency, dolomite, calcareous spar are additionally introduced. Cover hard porcelain with hard glaze. Thin varieties are glazed with lime-free spar, so the products are matte, milky-cream in color. But simpler varieties are covered with a completely transparent lime glaze.

Glaze and porcelain mass consist of the same substances, only in different proportions. Thanks to this, they are connected, and the glaze can no longer be beaten off or peeled off. hard porcelain, which is fired without glaze, is called "biscuit".

panther figurine, hard white porcelain, Augarten Wien

tea pairs, from the "Nyon" service, hard white porcelain, Herend

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are siblings, but not twins. The older brother is strong and strong - the younger is thin and hard. Faience is plentiful in body and coarse in appearance - porcelain is delicate in appearance and famous for its refined beauty. One of the brothers is dark by nature, but he likes to decorate himself colorfully and brightly. The other - shines with light and prefers pastel colors. At the same time, both do not shy away from gold - and glory!

Faience and porcelain - noble ceramics

This is where the similarities end.

Differences between porcelain and faience

Unpainted areas of porcelain and faience differ not only in light transmission, but also in color. Porcelain is always whiter than faience! The difference is determined by the recipe: faience contains more clay, which darkens during sintering. However, there are separate varieties of faience, the whiteness of which can compete with the whiteness of porcelain due to the additions and.

Crockery made of faience is usually thicker than porcelain counterparts. First of all, because the strength of faience is lower than the strength of porcelain. The relative fragility of faience is explained by the less "baking" of its shard. Numerous pores penetrating the earthenware thickness and making up up to 12% of the volume of ceramics reduce the object's resistance to mechanical stress.

Porosity contributes to the wetting of the ceramic mass. In order to reliably isolate faience from moisture, the glaze on the surface of the product is made with a layer thicker than that of porcelain. The thickened glaze smoothes the reliefs - that's why earthenware is simple in shape.

Faience and porcelain in the history of mankind

Pottery, made from light clay and covered with a layer of glaze, became known as faience in honor of the city of Faenza (province of Emilia-Romagna, Italy). Faenza manufactories became famous in the Renaissance - however, materials similar to modern faience were produced for a long time and everywhere, starting from ancient egypt and Ancient China, and ending with the most remote regions of the spread of civilization.

The invention of porcelain, associated with the discovery and development of deposits, spurred the growth in the quality of faience. It is safe to say that modern faience was born in an attempt to uncover the secret of porcelain recipes. Here's a causal paradox...

Artistic differences between porcelain and faience

Porcelain dishes are richer than earthenware relief details? So, she does not need abundant coloring. But the smooth contours of massive faience are like a primed canvas for a painter! Faience painting has long been a separate variety visual arts. True, the golden details of the artistic decor - strokes, ornamental stripes and solid edging - look equally advantageous on porcelain and faience.

Faience or porcelain: what is better in everyday life?

Porcelain is expensive and therefore suitable for making designer jewelry and ceremonial services. Faience is cheap to manufacture and therefore is used much more widely than porcelain.

At the same time, porcelain is not afraid of heating and sudden changes in temperature. In faience, such tests can cause cracking of the glaze, followed by moisture penetration into the shard. Strong coffee poured into a faience cup with microscopic cracks in the glaze will leave indelible marks...

Faience is not porcelain

Physical Properties:

• porcelain is whiter, faience is darker;
• porcelain is louder, faience is duller;
• porcelain is translucent, faience is opaque;
• porcelain is strong, faience is fragile.

• porcelain is dense, faience is porous;
• fused into a monolithic mass, sintered grains are observed in the faience structure;
• porcelain is covered with a thin glaze, faience glaze is thicker and not always uniform;
• porcelain tableware has an unglazed rim on the bottom. Earthenware dishes are most often covered with continuous glaze.

• porcelain figurines are beautiful with detailed details and amaze with the subtlety of plasticity. Faience objects are less intricate in form;
• The color range of faience products is rich in colors due to the painting over the glaze. Artistic porcelain is usually not as flamboyant;
• porcelain does not age. Over the years, faience products are covered with a network of small cracks (craquelure) - which does not in the least affect the value of antique faience.

• mass-produced porcelain is more expensive than mass-produced faience;
• porcelain antiques are not necessarily more expensive than rare earthenware.

Instead of a conclusion

Porcelain is the noblest and most perfect type of ceramics. As a rule, several main types are distinguished in porcelain: hard and biscuit, soft, bone.

HARD and BISCUIT

The German manufactory Meissen in Saxony became the discoverer of a new "hard" porcelain at that time. Hard porcelain is sometimes referred to as "real" porcelain. It contains much more kaolin and quartz in its composition. Hard porcelain has greater mechanical strength, density, resistance to heat, impermeability and chemical resistance. Due to the large presence of kaolin clays in the composition of the porcelain mass, their melting requires a higher firing temperature. It is 1350-1500°C. Accordingly, the product is harder. The glaze of such porcelain is thin and shiny. It consists of the same substances as the porcelain mass, only in different proportions, due to which it can be tightly and uniformly connected to the shard. It cannot be beaten off or peeled off.

Hard porcelain that is fired without glaze is called "biscuit". It is noteworthy that in the era of European Classicism, "biscuit" was used as inserts in furniture products.
In hard porcelain, the fragment is snow-white, smooth, even, shiny and with a sharp edge. To the touch, such porcelain is colder than soft. Meissen porcelain is classic hard porcelain.

SOFT

Soft porcelain is sometimes referred to as "artificial" as well as art or frit. The beginnings of such porcelain can be traced back to the 16th century in Italy, the so-called Medici porcelain. Its final formula was invented in France in 1673 in an attempt to find a formula for Chinese porcelain. It contains less kaolin, but more quartz, feldspar and mixtures of crushed vitreous substances, the so-called frits. The presence of minerals such as flint, saltpeter, sea ​​salt, alabaster, as part of soft porcelain, helps to increase the translucency of products and give them a delicate white-creamy color. The firing temperature of products made from such porcelain is below 1300 ° C, therefore its strength and heat resistance are much lower. Soft porcelain retains heat for a long time. The structure of such porcelain is porous, so the product from it is more fragile. The glaze on soft porcelain is much thicker than on hard porcelain. The composition of the glaze mainly consists of glass, that is, of a low-melting substance rich in lead oxide, and additionally containing sand, soda and lime. The unglazed part at the break of this type of porcelain is grainy. Most of the world-famous Chinese porcelain can be attributed to soft porcelain. The Sevres manufactory also mainly made its products from soft porcelain.

BONE

England is the birthplace of bone china. The formula for bone china as a type of soft china was discovered by the English ceramicist Josie Spoud in the mid-18th century. It is mainly used to create tea sets and tableware. The composition of the porcelain mass of bone china is 60% composed of lime phosphate - the ash of burnt bones cattle, which makes it possible to more easily melt the porcelain material. Horse bones are excluded in this case, since they give the dishes a yellowish tint. The hip bones of a cow turned out to be the most suitable. Bone china is fired at 1100-1500°C. Its glaze is basically the same as on soft porcelain, but contains, in addition to lead oxide, a certain amount of borax for better connection with skull. The glaze on bone and soft china is soft and brittle. The advantage of bone china is its extraordinary thinness and transparency. Bone china is more durable and harder than soft porcelain, but it is much inferior in its characteristics to hard Saxon porcelain.

It is a type of ceramic. Porcelain products are products obtained by sintering high-grade white clay (kaolin) with the addition of quartz, feldspar and other impurities. As a result of firing, the resulting material becomes waterproof, white, sonorous, translucent in a thin layer, without pores. Pottery is an art that has been practiced since ancient times by various cultures around the world.

Porcelain is believed to have been invented in China in the 6th-8th centuries AD, a thousand years before it was made in Europe. In this regard, the word "China" (China (English)) has become synonymous with porcelain (Chinese porcelain). For a long time Chinese craftsmen kept secret the technology of its production. However, after 500 years, China's neighbors, the Koreans, learned how to produce the so-called "hard" porcelain, that is, white clay products subjected to high-temperature firing. AT Central Asia porcelain came through the Great Silk Road in the 9th century. closer to XVI century the secret of making porcelain tableware Japan took over, and then European manufacturers. It was not until the end of the 17th century that porcelain production began in the United States.

Porcelain differs from other types of ceramics in composition and manufacturing process. The two most simple type ceramics, faience and stoneware are made using only natural clay, which is fired. In most cases, such products are coated with a glassy substance called glaze. Unlike faience and stoneware, porcelain is made from a mixture of two components - kaolin and Chinese stone (a type of feldspar). Kaolin is a pure white clay that forms when the mineral feldspar breaks down. Chinese stone is ground into powder and mixed with kaolin. This mixture is fired at a temperature of 1250°C to 1450°C). At such high temperatures, Chinese stone sinters, that is, fuses and forms a non-porous, natural glass. Kaolin, which is very resistant to heat, does not melt and allows the product to retain its shape. The process is completed when the Chinese stone is fused with kaolin.

Types of porcelain

There are several types of porcelain that differ from each other in production technology, quality characteristics and properties.

The main types are:
. soft porcelain;
. hard (high-temperature) porcelain;
. bone china.

Hard porcelain (high temperature porcelain)

Solid (real or natural) porcelain has always been the standard and model of excellence for the creators of porcelain. This is porcelain, which the Chinese were the first to produce from kaolin and Chinese stone. The proportions of kaolin and Chinese stone in the composition of hard porcelain can be different. It is believed that the more kaolin in porcelain, the stronger it is. Hard porcelain is usually quite heavy, opaque, has White color with a shade of gray, the enlarged surface resembles an egg shell due to small pits.

The technology for the production of hard porcelain is quite complicated, since the production of this type of porcelain requires very heat firing (1400-1600 °C), while the product is fired repeatedly. Hard porcelain is strong but breaks quite easily. It has a blue or gray tint if it is not subjected to special treatment. However, the materials used to make this type of porcelain are not expensive, and the quality of hard porcelain is inferior to that of bone china. Accordingly, hard china has a lower price than bone china.

Bone china

Bone china is a special kind of hard porcelain with the addition of burnt bone. Bone china is very durable, while it is distinguished by its special whiteness and transparency. Strength is achieved by melting the main ingredients during the firing process.

Bone china was first created in England in an attempt to recreate the formula for making the famous Chinese porcelain in Europe. At the end of the 18th century, bone ash was added to the porcelain mass. During the development of this technology, a basic formula for the manufacture of bone china: 25% kaolin (special white clay), 25% feldspar mixed with quartz and 50% burnt animal bones. The first firing is done at a temperature of 1200-1300 °C, the second firing is carried out at a temperature of 1050-1100 °C. For use in the composition of the porcelain mass, the bones are processed in a special way to remove glue from them and heated to a temperature of approximately 1000 ° C, while all organic matter are burned, and the structure of the bone changes to a state suitable for the production of bone china.

Due to its milky white color, transparency and strength, bone china has gained an excellent reputation and a leading position in sales in the world market. Distinctive features bone china dishes are light, thin-walled and transparent (fingers are visible through the walls to the light). There is no eggshell effect - this is achieved by the fact that it is bone ash that fills all the voids between particles of white clay.

soft porcelain

Soft (sometimes called faux) porcelain was created European masters who tried to reproduce Chinese hard porcelain. They tried to create a hard, white and transparent material from a variety of ingredients and obtained soft porcelain by mixing finely ground clay with a vitreous substance. Soft porcelain is fired at more than low temperatures than hard porcelain, so it does not sinter completely, that is, it remains slightly porous. It is believed that the first European soft porcelain was produced in Florence, Italy around 1575. In the 18th century, France became the leading producer of soft porcelain. The first manufactories for the production of soft porcelain were opened in Rouen, Saint-Cloud, Lille and Chantilly.

Soft porcelain has its advantages over hard porcelain. Most of products made from it have a creamy color, which some people prefer to the milky white color of hard porcelain. In addition, the paints that are usually used for painting soft porcelain merge with the glaze and give the products lightness and elegance.