Biscuit porcelain: characteristics, features, application. Types of porcelain

Tuesday, May 03, 2011 13:10 + to quote book

Porcelain (Turkish farfur, fagfur, from Persian fegfur) is the most noble ceramics. Porcelain tableware is white, durable tableware, characterized by amazing lightness and transparency. You can distinguish porcelain dishes from products made from other types of ceramics by the clear, long ringing sound that they make when struck.

Varieties and production technology

Porcelain is mainly made from kaolin, clay, quartz and feldspar. Some terminology:

Plavni in ceramic masses they play the role of thinning additives. When firing, fluxes promote the formation of a low-melting melt, reduce the firing temperature of products, and increase the density of the shard. Feldspar, pegmatite, nepheline syenite, perlite, chalk, dolomite, talc and other materials are used as fluxes in fine ceramic products. The action of smoothies in mass is not the same.
Feldspars are a universal flux in fine ceramics technology and in the production of glazes. The earth's crust consists of more than 50% feldspathic rocks, but deposits of feldspars suitable for the ceramic industry are very limited and mostly exhausted. They are aluminosilicates of alkaline and alkaline earth metals. Pegmatites, granites, and perlites can also be used in production.

Kaolin– white clay, which is formed during weathering of feldspars. It contains the mineral coalinite and is widely used in industry.

Quartz- another one of the most common minerals in the earth’s crust, a rock-forming mineral in most igneous and metamorphic rocks. It is part of other minerals in the form of mixtures and silicates. In total, the mass fraction of quartz in the earth's crust is more than 60%.

Usually two firings of porcelain products are carried out: the first for “salvage”, the second for “watered”. The first “scrap” firing aims to bake the product and provide it with a certain porosity and strength sufficient for glazing with an aqueous suspension. The second firing is necessary to melt the glaze on the surface of the product and allow it to interact with the shard material.

To improve the molding properties of the raw material, the porcelain mass used to make the famous Chinese “eggshell” porcelain, i.e. products with very thin walls, were kept closed in the ground for 100 years. Nowadays, clay can be subjected to flying, especially if it is of low plasticity. To do this, the excavated clay in the form of small pieces is laid out on the ground in beds, which are periodically watered with water, and shoveled. In this state, for several years the clay is exposed to water, sun, frost and significantly improves its properties. To make fine pottery, clay is soaked in water to remove impurities, coarse fractions are separated, and after partial dehydration, it rots in basements for several months.

Freshly precipitated barium sulfate BaSO4 is used as a standard for assessing the whiteness of porcelain. Whiteness is characterized by the intensity of light scattering, which is recorded by a photometer.

The term “porcelain” in the English-language literature is often applied to technical ceramics: zircon, alumina, lithium, boron-calcium and other porcelain, which reflects the high density of the corresponding special ceramic material.

Porcelain is also differentiated depending on the composition of the porcelain mass into soft and hard. Soft porcelain differs from hard porcelain not in hardness, but in the fact that when firing soft porcelain, more liquid phase is formed than when firing hard porcelain, and therefore there is a higher risk of deformation of the workpiece during firing.

Solid- with small additions of flux (feldspar) and therefore fired at a relatively high temperature(1380...1460°C). The mass of classic hard porcelain consists of 25% quartz, 25% feldspar and 50% kaolin and clay.

Soft– with a high content of flux, fired at a temperature of 1200...1280°C. In addition to feldspar, marble, dolomite, magnesite, burnt bone or phosphorite are used as fluxes. With increasing flux content, the amount of glassy phase increases and therefore the translucency of porcelain improves, but strength and heat resistance decrease. Clay imparts plasticity to the porcelain mass (necessary for molding products), but reduces the whiteness of the porcelain.

Soft porcelain is used primarily for the manufacture of artistic products, and hard porcelain is usually used in technology (electrical insulators) and in everyday use (dishes).

Porcelain products are very diverse in their chemical composition, properties and purpose. Several of the most famous types of porcelain and their characteristic features:

Biscuit porcelain– matte, without glaze. There is an opinion that it is called biscuit because it is fired twice. The prefixes "bis" and "bi" mean two in many languages. When producing porcelain, a firing process is first carried out, which is called waste firing, followed by a glaze firing. Bisque porcelain is also fired twice, but the second time without glaze. Currently, the technology for producing bisque porcelain may not include a second firing. In the era of Classicism, biscuits were used as inserts in furniture products.

Bone china– soft porcelain, indispensable integral part which is the ash of large bones cattle, consisting mainly of calcium phosphate. Currently, it is sometimes replaced by natural calcium phosphates. Products made from bone china are characterized by high whiteness, translucency and decorativeness. Experts believe that I. Spode began producing bone china in 1759 in the vicinity of Stoke-on-Treat (England). In our country, high-quality bone china products are produced by the Porcelain Factory named after. M.V. Lomonosov in St. Petersburg.

Fritted porcelain- highly translucent soft porcelain, produced in France since 1738. It contains 30...50% kaolin, 25...35% quartz, 25...35% alkali-rich glass frit. Frits are compositional additives to the porcelain mass that ensure the formation of a glassy phase, and therefore determine the translucency of porcelain. The composition of frits includes: sand, soda, saltpeter, gypsum, table salt and crushed lead glass.

A special place in the classification of porcelain occupies Chinese porcelain. The history of porcelain and the history of China are inextricably linked. In ancient times, jade was mainly used to make tableware in China. But it was too expensive material. The result of a long search by Chinese craftsmen to replace jade is porcelain, a material that is more accessible and easier to process. Jade remained a sacred stone in China, and porcelain almost immediately conquered the Chinese rulers.

Of all Chinese porcelain, white is especially distinguished. The secret of its unique fragility and at the same time strength lies in the raw materials from which it is produced. Jiangxi Province turned out to be rich in so-called porcelain stone, rock consisting of quartz and mica. By converting all the components into powder and adding kaolin, a mass was obtained, which was stored for many years so that it acquired the necessary plasticity. A special matte shine was achieved by applying several layers of glaze of varying transparency.

Chinese porcelain has become famous for its extraordinary thinness and weightlessness; the walls of the cups are so fragile that they resemble eggshells. Gained popularity in her homeland, first in high circles, and after and among the entire population, Chinese ceramics even BC. began to be exported first to India, Japan and Africa; and only in the 16th century to Europe.

Decoration

Colorful decor.

Porcelain is painted in two ways: underglaze painting and overglaze painting.

At underglaze In porcelain painting, paints are applied to unglazed porcelain. The porcelain piece is then coated with a transparent glaze and fired at high temperatures of up to 1350 degrees.

Palette of colors overglaze paintings are richer, overglaze painting is applied on glazed linen ( professional term unpainted white porcelain) and then fired in a muffle furnace at a temperature of 780-850 degrees.

During firing, the paint fuses into the glaze, leaving behind a thin layer of glaze. After a good firing, paints shine (except for special matte paints used only for decorative purposes), do not have any roughness and in the future better resist mechanical and chemical exposure sour food products and alcohol.

Professional overglaze painting is carried out using gum turpentine and turpentine oil. The paints are pre-soaked on the palette for a day or more. After work, they are thoroughly rubbed with the addition of turpentine oil. Turpentine in jars should be dry, slightly oily and oily (turpentine gradually changes from one state to another). The oil should also be more fluid and thicker. To work, take a piece of soaked paint, add oil and turpentine and dilute it to the consistency of thick sour cream. For brush stroke painting, the paint is diluted a little thicker, for pen painting - a little thinner. Underglaze paint is diluted with water, sugar with the addition of a small amount of glycerin.

Among the paints for painting porcelain, the group of paints prepared using noble metals stands out. The most common paints using gold, platinum and silver paint (or Argentine).

Gold paints with a low percentage of gold content are more decorative, and products decorated with them cannot be subjected to mechanical stress (washed with abrasive agents and in the dishwasher).

Relief decor.

This type of decor porcelain dishes embedded directly into the material of the object itself by engraving, perforation or through relief-like overstatements. Porcelain dishes are either cast in molds together with the relief, or the relief or plastic parts of the decor (flowers, buds, leaves, figurines as handles, etc.) are molded separately and then glued on.

Story

The composition of hard porcelain was invented by the Chinese around the 6th century, but this production secret was kept strictly secret. Chinese porcelain reached a high degree of perfection in the 15th and 16th centuries, and in the 16th century, thanks to Portuguese sailors, a large number of Chinese products came to Europe.

Around 1500, porcelain production was adopted by the Japanese. The Dutch contributed to the introduction of Japanese products to Europe in the 17th and 18th centuries, taking them with them on their way from Arita Harbor in Hitsen Province. This porcelain was called "imari" after the name of the main harbor where goods were loaded. Japanese porcelain shards are inferior in quality to Chinese ones, but their decor is much richer and more varied. In addition to the paints used by the Chinese, the Japanese decorated porcelain with gold.

From time to time, coming to Europe starting from the 13th century, Chinese porcelain was inserted into frames by European jewelers and, along with other precious objects, was kept in church, monastery and noble treasuries.

In the second half of the 15th century, the first attempts were made to imitate porcelain in Italy. In 1575, by the will of the Grand Duke of Tuscany, Francesco I di Medici, a soft porcelain manufactory was established in the famous Florentine Boboli Gardens. The so-called Medici porcelain, in its properties, occupied a middle position between hard and soft porcelain. The manufactory operated until the first quarter of the 17th century inclusive.

In the history of porcelain production, Medici porcelain is only an episode. It was followed by other attempts - in England (Dr. Dwight and Francis Place, both in the 2nd half of the 17th century) and in France (Rouen, Saint-Cloud). This ongoing search was stimulated by the increasing import of Far Eastern porcelain from the beginning of the 17th century. Until the beginning of the 18th century, all attempts remained unsuccessful - the result was materials that vaguely resembled porcelain and were closer to glass.

For example, Johann Friedrich Böttger (1682-1719) conducted experiments in the creation of porcelain, which in 1707/1708 led to the creation of “rothes Porcelain” (red porcelain) - fine ceramics, jasper porcelain.

However, real porcelain had yet to be discovered. Chemistry as a science in its modern understanding did not yet exist. Neither in China or Japan, nor in Europe could the raw materials for the production of ceramics be determined in terms of chemical composition. The same applied to the technology used. The process of porcelain production is carefully documented in the travel accounts of missionaries and merchants, but the processes used could not be inferred from these reports. For example, the notes of the Jesuit priest Francois Xavier d'Entrecole are known, containing the secret of the technology for the production of Chinese porcelain, made by him in 1712, but which became known to the general public only in 1735.

Letter from François Xavier d'Entrecole on the technology of producing Chinese porcelain, 1712, published by Duald in 1735.

The understanding of the basic principle underlying the porcelain production process, namely the need to fire a mixture of different types of soil - those that are easily fused and those that are more difficult to fuse - arose as a result of long systematic experiments based on experience and knowledge of geological, metallurgical and “alchemical-chemical” relationships. It is believed that Böttger's experiments in creating white porcelain were carried out simultaneously with those in creating "rothes Porcelain", since just two years later, in 1709 or 1710, white porcelain was more or less ready for production.

It should be noted that Chinese porcelain, from a modern point of view, is soft porcelain, since it contains significantly less kaolin than hard European porcelain; it is also fired at a lower temperature and is less durable.

Experts and scientists from various specialties worked together with Böttger to create solid European porcelain. European hard porcelain (pate dure) was a completely new product in the field of ceramics.

At the end of December 1707, a successful experimental firing of white porcelain was carried out. The first laboratory notes on usable porcelain mixtures date back to January 15, 1708. On April 24, 1708, an order was given to create a porcelain manufactory in Dresden. The first examples of porcelain fired in July 1708 were unglazed. By March 1709, Böttger had solved this problem, but he did not present glazed porcelain samples to the king until 1710.

In 1710, at the Easter fair in Leipzig, salable "jasper porcelain" tableware was presented, as well as examples of glazed and unglazed white porcelain.

History in Russia.

Attempts to organize the production of porcelain or earthenware in Russia began under Peter I, a great connoisseur of it. On the instructions of Peter I, Russian foreign agent Yuri Kologrivy tried to find out the secret of porcelain production in Meissen, but failed. Despite this, in 1724, the Russian merchant Grebenshchikov founded a faience factory in Moscow at his own expense, where experiments in the production of porcelain were carried out, but they were not properly developed.

The seemingly proven method of developing science and art in Rus' - inviting foreign specialists - also failed.
There was only one way left, the most difficult and long, but reliable: to organize search systematic scientific and technological work, which as a result should have led to the development of porcelain production technology. This required a person with significant training, sufficient technical initiative and ingenuity. This turned out to be Dmitry Ivanovich Vinogradov, a native of the city of Suzdal.

In 1736 D.I. Vinogradov with his comrades - M.V. Lomonosov and R. Reiser - on the recommendation of the St. Petersburg Academy of Sciences and by imperial decree was sent “to the German lands to study, among other sciences and arts, especially the most important chemistry and metallurgy, to this end that concerns mining or manuscript art.”
D.I. Vinogradov studied mainly in Saxony, where at that time there were “the most famous manuscript and smelting factories in the entire German state” and where the most skillful teachers and masters of this craft worked at that time. He stayed abroad until 1744 and returned to Russia with certificates and certificates conferring on him the title of “Bergmeister,” which in those days enjoyed great authority.

Vinogradov was faced with the task of independently resolving all issues related to the creation of a new production. Based on physical and chemical ideas about porcelain, he had to develop the composition of the porcelain mass, technological techniques and methods for producing a mass of real porcelain. This includes the development of glazes, as well as formulations and manufacturing technologies for ceramic paints of different colors for painting on porcelain.

More than a thousand different experiments were performed by Vinogradov during his work at what was then called the “porceline factory.”

In Vinogradov’s works on organizing porcelain production in Russia, his search for a “recipe” for porcelain mass is of significant interest. These works relate mainly to 1746-1750, when he intensively searched for the optimal composition of the mixture, improved the recipe, leading technological research on the use of clays from various deposits, changing the firing mode, etc. The earliest of all the information discovered about the composition of the porcelain mass has a date of January 30, 1746. Probably, from that time, Vinogradov began systematic experimental work to find the optimal composition of Russian porcelain and continued it for 12 years, until his death, i.e. until August 1758

Since 1747, Vinogradov began making trial products from his experimental masses, as can be judged from individual exhibits stored in museums and bearing his brand and date of manufacture (1749 and later years). In 1752, the first stage of Vinogradov’s work on creating the recipe for the first Russian porcelain and organizing technological process its production.

It should be noted that when compiling the recipe, Vinogradov tried to encrypt it as much as possible. He did not use the Russian language, but used Italian, Latin, Hebrew, and German words, also using their abbreviations. This is explained by the fact that he was given special instructions about the need to keep his work as secret as possible.

Vinogradov’s successes in the production of porcelain at the porcelain factory at this time were already so significant that on March 19, 1753, an announcement appeared in the St. Petersburg Gazette about accepting orders for porcelain “bag snuff boxes” from private individuals.

In addition to developing the formulation of porcelain masses and studying clays from various deposits, Vinogradov developed glaze compositions, technological methods and instructions for washing clays at deposits, tested various types of fuel for firing porcelain, drew up designs and built furnaces and furnaces, invented a formulation of paints for porcelain and decided many related problems. We can say that he had to develop the entire technological process of porcelain production himself and, in addition, at the same time prepare assistants, successors and employees of various qualifications and profiles.

As a result of “diligent work” (as he himself assessed his activities), original Russian porcelain was created. The factory has achieved great success both in the quality of porcelain and in the variety of products made from it. In conclusion, it should be noted that M.V. Lomonosov also took a significant part in the creation of original porcelain in Russia, although his share of participation in this matter was incomparably less than that of D.I. Vinogradov. Which, however, did not prevent the Imperial Plant from being subsequently named after Lomonosov, and not Vinogradov.

Labeling of porcelain products

Marking as a way to indicate that a product belongs to a specific production began to be used in Europe soon after the creation of large ceramic manufactories. But long before this, for example, oriental (Japanese and Chinese) marks were reproduced on Delft faience of the 17th century. By the way, the largest European porcelain factories - Meissen and Vienna - also started with these same brands.

Original stamps were first introduced in Europe at the Meissen manufactory in 1723-24. Following this, other factories began to label their products. The stamps, as a rule, were blue underglaze and were placed on the bottom of the product. For a long time, the presence or absence of a mark was left to the discretion of the porcelain manufacturers themselves, and only in the last third of the 18th century in the main manufacturing countries (France, Germany, Austria) marking became mandatory, and marks had to be registered in the relevant public services.

As the number of porcelain productions in Europe increases and the obvious leadership is recognized, and therefore of greatest value products of Sevres, Meissen, Vienna and some other manufactories, such a marking function as protection against imitation and counterfeiting began to come to the fore. For this purpose, for example, in the 19th century, Sèvres, Vienna and Berlin introduced the practice of double marking: one mark - usually blue underglaze - was placed during the manufacture of the product, a second - most often red - during its overglaze decoration.

Example of early Ming Dynasty porcelain markings

If we talk about the content of brands, then with all their diversity, the following main elements can be distinguished: names of factories or cities (localities) where they are located; surnames, initials or monograms of the owners or their high patrons; heraldic motifs - crowns, coats of arms or parts of coats of arms; figures of animals, birds, fish; flowers or other plants; ships, anchors, other marine motifs; castles and various buildings; religious or mythological motives; various kinds of emblems and symbols; geometric figures.

If the product is not marked, then it has to be identified by the method of execution, shape, nature of the shard, glaze color and decorative style. Marking marks for porcelain and earthenware are collected in special reference books and catalogs.

P.S. According to historians, a porcelain cup with a handle - the one we fill with fragrant tea every day - appeared not so long ago. It really happened an important event around 1730 in Vienna, when some inventive and enterprising porcelain maker came up with the idea of equipping the Chinese gaiwan (bowl) with a side handle, and this design became more convenient for Europeans - after all, for many years before that, they had been drinking coffee from metal cups with with a pen, and water, beer or milk from mugs.

Pottery is one of the most ancient crafts on Earth. From its inception to this day, clay products are used every day almost everywhere: in everyday life, technology, construction, transport and many other areas of life. With the development of progress, the range of goods and the materials used to make them have expanded significantly. Porcelain, earthenware, majolica... It’s easy for an ignorant person to get confused. How to distinguish them from each other and what to choose?

What is the difference between ceramics and porcelain and earthenware?

A short excursion into the history of the appearance of these materials and their manufacture will help us answer the question about the difference between faience and porcelain or ceramics.

A little history

If we talk in simple language, then ceramics are fired clay. People learned to make the first ceramic objects in ancient times, long before the advent of our era. Thus, the first products made of baked clay date back to 29-25 millennia BC. With the development of this trend, a variety of materials began to be added to clay. inorganic substances and mineral supplements. But only at the beginning of our era more advanced materials were invented - earthenware and porcelain. They are a type of ceramics and differ from each other in composition, production conditions and characteristics.

Ceramic products are produced by sifting and mixing clay with mineral additives and inorganic compounds, and then fired at very high temperatures (up to 1500 degrees Celsius). Depending on the amount of additives and firing temperature, fine and coarse ceramics are distinguished. Fine ceramics have a fine-grained or glassy shard, while coarse ceramics have a coarse-grained shard. The first includes porcelain, majolica, earthenware and other types, and the most popular and expensive of them are earthenware and porcelain. Coarse ceramics are materials obtained during the pottery production process.

Earthenware and porcelain have similar production. They are made from the same materials, but taken in different proportions and fired under different conditions. At the first stage, the raw materials are prepared and processed, sifted and filtered. After this, the mass is kept in a cool room and processed again. At subsequent stages, the products are formed, dried, fired in special ovens and decorated using special paints and relief decor.

Faience is a material that contains more impurities than clay, and the firing temperature is 1000–1300 degrees. It is used most often for household purposes (for example, everyone in the house has earthenware). Porcelain contains a higher percentage of clay and is fired 2 times - before applying the glaze and after. In this case, the second firing occurs at a temperature of about 1500 degrees. In addition to household use, it is used for decorative and research purposes (for example, in laboratories).

It is not difficult to distinguish porcelain or earthenware from ceramics. Porcelain and earthenware look delicate, elegant and beautiful, while ceramics seem rougher and less skillful. It is much more difficult to distinguish porcelain from earthenware. Let's name the main differences:

porcelain, even covered with glaze, shines through in the sun's rays, while earthenware is dense and does not allow light to pass through;
on the lower part of a porcelain figurine or cup there are necessarily roughnesses due to the fact that the bottom is not covered with glaze, while the surface of earthenware is completely smooth and has no irregularities;
if you lightly hit a porcelain product, it makes a long, high-pitched sound like a crystal ringing, while earthenware makes a sharp crack, similar to the sound of broken glass or a dull sound;
earthenware has low thermal conductivity properties, so the handle of a earthenware cup with hot tea will always remain cold, while the porcelain container will heat up;
Despite the fact that porcelain has no pores, it is much lighter than earthenware.

Products made of porcelain, earthenware and ceramics

Ceramics turned out to be such a practical material that objects from its different types are very extensive. Let's consider their main groups from the field of decorative and applied arts.

Behind porcelain products lies a centuries-old history from the heroic invention of the recipe to the discovery of the finest forms and the purest paints for painting. Thanks to the work of talented craftsmen from all over the world, porcelain tableware was born that is striking in its beauty and diversity. These are luxurious for the royal table, exquisite and mesmerizing with the subtlety of the design, and much more.

The second group of porcelain products is represented by interior items. These are a variety of flowerpots, chandeliers, iconostases, etc. These are figurines and porcelain layers.

They have enjoyed success at all times, because porcelain makers in this direction managed to achieve unprecedented skill. Looking at the figurines, we, together with the authors, experience the cheerfulness of a milkman starting a new day, the joy of frolicking animals, admiring the beauty of porcelain princesses or reflecting on life while seeing genre scenes.

They are picturesque paintings, panels or inserts that never fade or crack. Bright and skillfully made porcelain paintings will immortalize an event or become an expensive gift for an art connoisseur.

The third group is household items. These are inkwells, press folders for papers, cutting knives and others that will not only decorate the room, but also be useful in everyday life.

Earthenware products are also very diverse. This includes numerous earthenware dishes, elegant figurines, and household items. They cost less than porcelain products, but they will also last much less than their porcelain counterparts. Earthenware is more fastidious in care (more on the properties of earthenware below).

Vases, jugs, tea pairs, sugar bowls and other utensils are also made from ceramics. Ceramic products are thicker and rougher and are best suited for making large dishes or household items.

More ceramics, good and different!

There are many more varieties of ceramics. The highest grade faience with the least amount of impurities is opaque. It is whiter than traditional earthenware and more durable. The art of majolica - elegant painting on decorative items and finishing tiles - is widely known throughout the world. For better distribution of paint on the surface, highly porous clay is used, fired at low temperatures, onto which opaque enamel is applied. This clay is used as a raw material and has no value in itself.

IN individual species Ceramics can be distinguished into so-called hard and soft porcelain. Hard porcelain contains more kaolin, sometimes cow bone ash is added to it. Soft porcelain is actually such and is more susceptible to mechanical damage.

In general, according to the complexity of the technological process and cost, types of ceramics can be arranged in the following order (from cheap to expensive): majolica - faience - opaque - porcelain.

Earthenware or porcelain - which is better to buy?

When choosing dishes, the question invariably arises: whether to give preference to porcelain or earthenware. The characteristics of these materials will help answer this question.

The advantages of porcelain are:

has excellent quality, including a flawless glazed surface;
resistant to temperature changes;
distinguished by its sophistication, variety of shapes and splendor of decoration;
Dishwasher resistant;
resistant to aggressive detergents;
environmentally friendly;
has low moisture absorption (less than 0.2%);
The service life of regularly used products exceeds 50 years.

Faience has the following characteristics:

It has good quality;
due to temperature changes, microcracks may appear in it; when coloring substances (coffee, tea) get into them, indelible marks remain;
the products are varied, elegant and beautiful, but are not distinguished by such whiteness and thin walls as porcelain;
the earthenware coating may be damaged by washing in hot water and in the dishwasher;
has a relatively low moisture absorption level of 9-12% (much more than porcelain, which means a greater risk of cracks and chips);
the service life of regularly used products is about 20-25 years;
costs much less than porcelain.

As we can see, porcelain is superior to earthenware in many properties. Porcelain dishes are more durable, practical and elegant, but they are also more expensive. However, the latter does not apply to rare items. Antique earthenware can cost more or equal to antique china. Here, a lot depends on the rarity, age of the item, the fame of its author and other factors.

You can purchase antique porcelain, earthenware or ceramics in our gallery. We have collected for you a collection of the best factories and craftsmen of past centuries. Famous or rare porcelain and many other porcelain companies are presented in our catalogue. To order, go to the page of the product you like and read the terms of sale.

Types of porcelain

Ceramics

True ceramic is a dark, opaque, vitrified product and, when broken, always colored, sometimes brown and often light grey.

Ceramics were freely combined with local clay deposits. The clay itself ensures that the flux powder transitions to a vitrified state at temperatures between 1100-1300’C.

Basically, real ceramics has non-standard components, but consists mainly of natural clay. Typically, additions of other components are not included.

Ceramics can be made from purified clay, which usually gives the pottery a dark yellow color, the flux then adds a vitrified appearance to the product at the required temperature.

This condition applies loosely to items including tableware and cookware that may be used in the oven and then placed directly on the table. Both, clay and various glazed substrates, are sometimes used in this direction. Ideally, bakeware should be made from a glass base that has low thermal expansion.

However, sometimes it is produced cheaply, Low quality, clay kitchenware that does not require a complex technological process. Even with casserole dishes/cooking utensils, you need to take care of both the cookware itself and to avoid uneven baking, which can cause pressure inside the item and increase the possibility of thermal shock.

The most basic materials used to produce ceramic products

Clay

The clay can be cream or white Thus, the cream shade contains a higher percentage of ball clay, the white shade contains a higher percentage of white clay. A type of clay base becomes porous when fired. Absorbs about 6-8% water and becomes lighter in weight.

The advantage of clay is that it can be fired unglazed at least 12 items at a time. When glazed firing, pin levers should be used separately on the ware; this is the reason for the creation of the 3-pin brand standard. This also makes it possible to capture the largest surface area during firing; The main difference between clay and other bases is that the factory can produce large volumes in spans, making the product very attractively priced for production. Clay bases are generally not recommended for use in restaurants and hotels as they deteriorate and have poor impact protection compared to other bases.

Vitrified clay

This characteristic applies to bases that have a water adsorption of less than 0.5%. When such a base is fired, it increases strength and reduces the likelihood of chipping, increasing the life of the cookware. Because, low thermal expansion will give better thermal capabilities. This product can be recommended for use in restaurants and hotels, as well as for baking.

Porcelain

The word porcelain is used as a term that includes all ceramic dishes, which is white and translucent. Bone china may, for example, be included in this classification, although it is certainly not porcelain.

Porcelain is a white, translucent glazed product that is usually fired at a low temperature, resulting in a blue-gray hue to the porcelain.

Porcelain can be glazed or unglazed; unglazed porcelain can be used to make figurines. The production process for glazed porcelain allows the decoration to be applied either in the firing or in the glaze.

A solid porcelain mass, the most typical for porcelain tableware, the first firing takes place at a temperature of 900-1000'C, giving sufficient strength to the base, then the glaze is applied to the base and fired at a temperature from 1400'C to the required temperature.

The composition of the soft porcelain mass includes more flux and less clay, this allows the glaze and base to be fired together at lower temperatures of 1250-1300’C.

Bone china

Bone china has a base that is extremely white, glazed, and translucent. Curved pin marks are not possible on this basis, and therefore, each item must be mounted on individual mounting mechanisms and each item placed on a stand. As a result of this, you need more space in a kiln. Added to this is the cost of the material and bone china becomes one of the most expensive bases.

Types of porcelain

Porcelain is the noblest and most perfect type of ceramics. At the same time, it differs from all other types in some special properties, for example, in the fact that its mass is absolutely white not only on the surface, but also in the fracture.

Transparency is also characteristic in the thinnest places of the shard. Have you tried reading through porcelain? This cannot be done through a plate of modern production, but through a saucer or the wall of a tea cup, which was made in the 17th century. Chinese masters, it is quite possible to distinguish large letters - the shard is so thin.

Porcelain consists of a mixture of different types of clay and a translucent glaze that covers the shard. If the twice-fired porcelain mass is left without glaze, as was customary at some porcelain factories in the manufacture of small plastic items, medallions, and, less commonly, tableware, such porcelain is called bisque porcelain.

Depending on the composition of the porcelain mass and glaze, hard and soft porcelain are distinguished. An intermediate type is represented by the so-called bone china.

Hard porcelain

contains mainly two starting materials: kaolin (pure clay - a refractory, fatty and extremely plastic mass) and feldspar (most often combined with white mica - melts relatively easily). Quartz or sand is added to these basic substances.

The properties of porcelain depend on the proportion of two main substances: the more kaolin its mass contains, the more difficult it is to melt and the harder it is. This mixture is ground, kneaded, washed and then dried to a dough-like state. A plastic mass appears, which can either be cast in molds or turned on a potter's wheel. Molded objects are fired twice, first at 600-800°C, and then with glaze - at 1300-1500°C.

The glaze consists of the same components as the shard, only in different proportions, and thanks to this, a completely homogeneous mass can be combined with the shard. The glaze cannot be beaten off or peeled off.

Hard porcelain is distinguished by its strength, strong resistance to heat and acids, impenetrability, transparency, conchoidal fracture, and finally, a clear bell sound. In Europe, it was invented in 1708 in Meissen by Johann Friedrich Boettger.

Soft porcelain,

also called artistic or frit, consists primarily of mixtures of glassy substances, so-called frits, containing sand or flint, saltpeter, sea salt, soda, alum and crushed alabaster. After some melting time, marl containing gypsum and clay is added to this mass. This entire mass is ground and filtered, bringing it to a plastic state. The molded object is fired at 1100-1500°C, making it dry and non-porous.

The glaze is predominantly made of glass, that is, a fusible substance rich in lead oxide and containing sand, soda, potash and lime. Already glazed products are subjected to secondary firing at 1050-1100°C to combine the glaze with the shard.

Compared to hard porcelain, soft porcelain is more transparent, its white color is delicate, sometimes almost creamy, but the heat resistance of this porcelain is lower. The fracture is straight, and the unglazed part in the fracture is grainy.

From the beginning, European porcelain was in most cases soft, as exemplified by the fine and highly prized ware of old Sèvres. It was invented in the 16th century in Florence (Medici porcelain).

Bone china

represents a well-known compromise between hard and soft porcelain. Its composition was discovered in England, and its production began there around 1750.

In addition to kaolin and feldspar, it contains lime phosphate from the burnt bone, which makes smelting easier. Bone china is fired at 1100-1500°C. We are essentially talking about hard porcelain, but one that is made softer by mixing in burnt bone.

Its glaze is based on the same as on soft porcelain, but contains, in addition to lead oxide, a certain amount of borax for better connection with a shard. At the appropriate temperature, this glaze melts and bonds firmly to the shard.

In its properties, bone china occupies an intermediate position between hard and soft. It is more durable and harder than soft porcelain and less permeable, but it has a fairly soft glaze. Its color is not as white as that of hard porcelain, but whiter than that of soft porcelain. Bone china was first used in 1748 in Bow by Thomas Fry.

Porcelain decoration

There are two fundamentally different types of decor: relief or plastically applied decor and painting. Relief decoration is embedded directly into the material of the object itself - by engraving, perforation or through relief-like overstatements. The object is either cast in molds together with the relief, or the relief or plastic parts of the decor (flowers, buds, leaves, figures as handles, etc.) are formed separately and then glued on.

Colorful decor is performed either under the glaze or above it. During underglaze painting, which is especially common on Chinese porcelain, metal oxides that can withstand high heat (cobalt, hematite) are applied directly to the shards and then fired along with the glaze.

The oldest overglaze technique is painting with enamel paints, the palette of which is quite limited.

On hard porcelain, paints often stand out plastically on the surface of the glaze, since they cannot be fired at high temperatures and therefore do not combine with the glaze. On soft porcelain, they often melt along with the glaze and merge with it. So-called muffle paints and gilding are also applied to the glaze. Muffle paints are lead or drill glazes colored with metal oxides that melt at low temperatures. The glaze contained in the paint acts like a flux, combining the paint with the background glaze during heat, so that the paint does not protrude. Firing occurs at 600-800°C.

Visiting a restaurant is an opportunity not only to eat deliciously, but also to have a good time. A beautifully set table with exclusive porcelain tableware will add sophistication and uniqueness to even an ordinary dinner - nuances that distinguish restaurants and cafes high level from regular catering establishments.

Do you often have to cut up carcasses? Description necessary equipment link.

Czech companies

Czech porcelain produced by Rudolf Kämpf is known under three brands:

Actually Rudolf Kämpf - Handmade premium class for an exclusive consumer.
Leander - tableware and porcelain products for consumers in the mass‑market segment.
Leander HoReCa - professional porcelain tableware for hotels and restaurants.

The products of Rudolf Kämpf are very diverse and at the same time original. The factory's craftsmen also create exclusive tableware in various styles: romantic, futuristic, art deco, etc. Designers are constantly finding new solutions, embodying them in porcelain, for example, products based on the masterpieces of Salvador Dali.

Prices for products vary: from very affordable for Leander HoReCa porcelain to high for dishes for individual use.

Yulia Artyukhova, brand manager at RADIUS, shares her impressions of the dishes:

Professional tableware from the Czech factory Rudolf Kämpf creates new possibilities for serving. Excellent products often unusual shapes and avant-garde design solutions. The quality is simply amazing. This type of cookware is very pleasant to use. The warmth put in by the craftsmen emanates from it.

This is a white, durable clay dish characterized by amazing lightness and transparency. You can distinguish porcelain dishes from products made from other types of ceramics by the clear, long ringing sound that they make when struck.

Porcelain tableware symbolizes luxury and comfort. A porcelain tea set can turn an ordinary breakfast into a ceremony of beauty and taste. Using elegant porcelain cups and plates, you not only enjoy the true taste of drinks and dishes, but also receive extraordinary aesthetic pleasure. One of the important advantages of porcelain tea sets is their amazing ability to retain the warmth of drinks. Porcelain dishes can decorate your home and improve your mood. Among wealthy people Lately It has become fashionable to purchase porcelain dishes to match the style and interior design of your home.

History of porcelain tableware

Porcelain dishes are a classic. Time simply has no power over her.

Porcelain dishes appeared back in the fourth century in China. And for ten centuries it gave joy only to its founders-producers. This precious gift from the Chinese to the world was seen by the Old World only in the 14th century. But it was immediately received with a bang. Europeans valued amazingly beautiful and airy porcelain dishes as worth their weight in gold. And not only figuratively, but also literally: porcelain dishes in those days were very expensive pleasure. Not everyone could afford to buy it for their home. Meanwhile, Chinese manufacturers for a long time kept the secret of porcelain tableware production. Europeans could not figure out the secret of its manufacture. Only at the beginning of the 18th century was the German alchemist Better able to finally reveal the secret of porcelain production. It turned out that the Chinese obtained it from kaolin (white clay) and feldspar by firing at high temperatures. Thanks to Better's discovery, today we can all enjoy the convenience and beauty of porcelain tableware in our homes.

Types of porcelain

Depending on the composition and processing method, the following types of porcelain tableware are distinguished:

soft porcelain dishes;
bone china dishes;
dishes made of hard porcelain.

Porcelain dishes certainly contain elements such as kaolin, spar and clay.

“Real” (hard porcelain) is often called spar porcelain, based on its main constituent element.

Hard and soft varieties of porcelain differ from each other in the concentration of kaolin. The more of this substance in the composition, the harder the porcelain becomes.

As for hard porcelain, it has amazing strength, amazing heat resistance, and good resistance to acids. Externally, dishes made of hard porcelain are distinguished by their refined transparency, snow-whiteness, giving off a faint blue, and conchoidal fracture.

Soft porcelain contains glassy substances (frits) in large quantities. This porcelain can be described as a fused glass-like substance with a small proportion of clay. Externally, dishes made of soft porcelain are distinguished by even greater transparency, a creamy white tint, and a straight (grainy in areas not covered with glaze) fracture. Soft porcelain is inferior to the hard variety not only in terms of whiteness and strength, but also in resistance to high temperatures.

Bone china got its strange name due to its unusual composition. In addition to kaolin and feldspar, this porcelain contains lime phosphate from burnt bone. In terms of quality characteristics, bone china is somewhere between soft and hard varieties. Unlike soft porcelain, bone porcelain has greater strength, hardness, and a lower degree of permeability. But these two varieties have the same soft glaze. The color of bone china is whiter than that of soft china, but not as snow-white as that of hard china.

All three types of porcelain dishes are suitable for use in the kitchen. However, dishes made of hard porcelain are more valued due to their perfect whiteness, amazing strength and heat resistance. It can even be found in high-end restaurants and at dinner parties. outstanding people states. The remaining varieties of porcelain are less popular in high society, but are simply irreplaceable in our everyday life!

Porcelain tableware decor

Today, the most popular dishes are made from natural white porcelain, classic, without any decoration. Pure porcelain tableware - elegant and luxurious - simply demonstrates its high origin and exceptional external properties. The series of white porcelain tableware differ only in design; the quality of the products in all is equally impeccable.

However, many people prefer original porcelain sets with unique decor.

There are two main types of porcelain tableware decoration:

Colorful decor.

This decoration of porcelain dishes is done either under the glaze or above it. As for underglaze painting, it is especially common on Chinese porcelain. This method involves applying a design directly to the shard, after which the product is fired along with the glaze. The oldest overglaze technique is painting porcelain dishes with enamel paints, the disadvantage of which is that their palette is rather limited.

Different types of porcelain have their own characteristics of drawing. On hard porcelain, for example, such paints often stand out plastically on the surface of the glaze, since they cannot be fired at high temperatures and therefore do not combine with the glaze. On soft porcelain, they often melt along with the glaze and merge with it.

Relief decor.
This type of decoration of porcelain tableware is embedded directly into the material of the object itself by engraving, perforation, or through relief-like elevations. Porcelain dishes are either cast in molds together with the relief, or the relief or plastic parts of the decor (flowers, buds, leaves, figurines as handles, etc.) are molded separately and then glued on.

Caring for porcelain dishes

One of the disadvantages of porcelain dishes is that after prolonged use they darken and lose their flawless original appearance. But porcelain dishes can always be restored to their former whiteness by wiping them with baking soda, or salt and vinegar, or a piece of cloth moistened with turpentine or tartaric acid. Stains on porcelain dishes (plates, soup bowls, etc.) can be removed by wiping them warm water with the addition of a small amount ammonia. To preserve the design on porcelain dishes, it is not recommended to wash them very much. hot water. To keep porcelain plates that are rarely used well, you can line them with white paper cut to the size and size of the plates.

Video: making porcelain tableware

Date of publication - 05/05/2008
Update date - 12/10/2010
Reproduction without an active link is prohibited!

Olga 01.04.2014 17:27
A friend bought porcelain saucepans from the Lakidaki store, brand Vabene. Has anyone bought this brand? How high quality is it? What are the differences between using metal pans?

Yana 22.05.2013 10:27
Natalya, bone china of the traditional recipe had a milky white color, but now the shade depends on the manufacturer’s factory.

Natalia 22.05.2013 10:13
So what color is bone china?? As I understand it, it no longer looks blue, but it doesn’t sparkle with white either???:ir:

Anastasia 05.01.2013 12:36
Lyudmila, no: the unpainted bottom of porcelain dishes does not at all indicate a defect. This is a common occurrence. It is said that this unglazed fragment of a cup/saucer reveals the true color of the porcelain.

Lyudmila 30.11.2012 23:33
Very interesting article. I bought some cups and decided to read about porcelain. Enough information, thank you. And if the glaze on the bottom is a little worn off, is it a defect?