How porcelain dishes are made. Everything about porcelain: types, classification, painting. Custom orders, busts and fight

Porcelain vase

Porcelain has always been highly prized and can last for decades, and having china has always been considered a sign of wealth. And what is porcelain made of? What types of porcelain are there? How do porcelain dishes?

Porcelain composition

Porcelain is usually obtained by high-temperature firing of a coarsely dispersed mixture of kaolin, quartz, feldspar and plastic clay (mainly kaolin, with inclusions of chromophore ions).

Depending on the composition, porcelain is divided into hard and soft. The hardness of the finished porcelain is the same, and they got these names because more liquid phase is formed in the manufacture of soft porcelain.

The composition of hard porcelain includes:

47-66% kaolin,
25% quartz,
25% feldspar.

Hard porcelain is richer in kaolin (alumina) and poorer in fluxes. To obtain the necessary transparency and density, it requires a higher firing temperature of 1400 ° C to 1460 ° C.

The hardest porcelain is bone china, which contains up to 50% bone ash, as well as kaolin, quartz, etc., and which is distinguished by its special whiteness, thinness and translucency.

Hard porcelain is usually used in technology (electrical insulators) and in everyday life, more often as dishes.

Soft porcelain consists of:

25-40% kaolin,
45% quartz,
30% feldspar.

The firing temperature usually does not exceed 1300-1350 ° C.

Soft porcelain is used primarily for the manufacture of art products.

Mostly porcelain is glazed. White, opaque, non-glazed porcelain is called biscuit.

Porcelain is painted in two ways:

underglaze painting,
overglaze painting.

Porcelain painting

From the names it is clear how the painting is applied to the porcelain. With underglaze painting on porcelain, paints are applied to unglazed porcelain. Then the porcelain is covered with a transparent glaze and fired smoothly at temperatures up to 1350 degrees.

Overglaze painting is applied on glazed unpainted white porcelain and then fired in a muffle furnace at a temperature of 780 to 850 degrees.

During firing, the paint is fused into the glaze, leaving thin layer 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 the mechanical and chemical effects of acidic food products and alcohol.

The overglaze painting palette is richer than the underglaze painting palette.

Now, using porcelain dishes at home, you will know what they are made of.

Introduction

Porcelain is the main representative of fine ceramics. The characteristic features of porcelain are white with a bluish tinge, low porosity and high strength, thermal and chemical resistance and natural decorative effect. Its features are determined by the chemical composition and structure of the shard, which depend on the purpose of the product, the conditions of their operation and the requirements imposed on them.

Porcelain has high mechanical strength, chemical and thermal resistance, electrical insulating properties and is used for the manufacture of high-quality tableware, decorative and sanitary ware, electrical and radio engineering parts, corrosion-resistant chemical technology devices, low-frequency insulators, etc.

Porcelain is usually obtained by high-temperature firing of a fine mixture of kaolin, feldspar, quartz and plastic clay (this kind of porcelain is called feldspar). The term "porcelain" in the English-language literature is often applied to technical ceramics: zircon, alumina, lithium, boronic and other porcelain, which reflects the high density of the corresponding special ceramic material.

Porcelain is also distinguished depending on the composition of the porcelain mass into soft and hard. Soft porcelain differs from hard porcelain not in hardness, but in 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.

Hard porcelain is richer in alumina and poorer in fluxes. To obtain the required transparency and density, it requires a higher firing temperature (up to 1450 ° C). Soft porcelain is more varied in chemical composition... The firing temperature reaches 1300 ° C. Soft porcelain is used mainly for the manufacture of artistic products, and hard porcelain is usually used in technology (electrical insulators) and in everyday use (dishes).

One of the types of soft porcelain is bone china, which contains up to 50% bone ash, as well as quartz, kaolin, etc., and which is distinguished by its special whiteness, thinness and translucency.

Porcelain is usually coated with glaze. White, opaque, non-glazed porcelain is called biscuit. In the era of Classicism, biscuit was used as inserts in furniture products

PRODUCTION PROCESS

Preparation of raw materials

The composition of the ceramic mass and the method of its preparation are determined based on the purpose of the product, its shape and type of raw material. The purpose of the preparation of raw materials is the destruction of the natural structure of materials to the smallest particles in order to obtain a homogeneous mass and accelerate the interaction of particles in the process of porcelain formation. It is carried out mainly by a plastic method, which provides a mass uniform in composition.

Plastic materials (clay, kaolin) are dissolved in water in paddle mixers. The resulting mass in the form of a suspension is passed through a sieve (3600 - 4900 holes per 1 cm2) and an electromagnet to remove large inclusions and ferrous impurities.

Depleted materials and fluids are sorted, freed from foreign and harmful impurities. Quartz, feldspar, pegmatite and other components are fired at a temperature of 900-1000 ° C. In this case, quartz undergoes polyform changes, as a result of which it cracks. This, firstly, facilitates grinding, and secondly, it allows you to remove pieces contaminated with ferrous impurities, since during firing quartz with impurities of ferrous compounds acquires a yellow-brown color.

Stony materials, including broken porcelain, are washed, crushed and coarsely ground on runners, and then sieved. Fine grinding is carried out in ball mills with porcelain or uralite balls. To intensify grinding, a surface-active additive is introduced into the mill - sulfite-alcohol stillage (from 0.5 to 1%), which, filling microcracks, has a wedging effect, as it were. Grinding is carried out to a residue of 1-2% on a sieve with 10,000 holes per 1 cm2.

Plastic and lean materials, fluff and porcelain breakage are thoroughly mixed in a propeller-type mixer. The homogeneous mass is passed through a sieve and an electromagnet and dehydrated in special filter presses or vacuum filters. The resulting plastic mass with a moisture content of 23-25% is sent for two weeks to aging in a room with high humidity. During aging, oxidative and microbiological processes, hydrolysis of feldspar and the formation of silicic acid occur, which promotes loosening of the mass, further destruction of the natural structure of materials and an increase in the plastic properties of the mass. After aging, the mass is processed on mass mills and vacuum presses to remove air inclusions, as well as plasticity and other physical and mechanical properties necessary for the formation of products.

Types of porcelain

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

Hard porcelain contains mainly two starting materials: kaolin and feldspar (most often in combination with white mica; it 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, milled and then dried to the degree of a doughy state capable of taking shape. A plastic mass is formed, which can either be cast in molds or grinded on a potter's wheel. Finished items are fired twice: first without glaze at a temperature of 600-800 degrees C, then with glaze - at 1500 0 C. Feldspar or pegmatite is used as fluff. “Sometimes dolomite and lime spar are additionally introduced to enhance translucency. Cover hard china with hard glaze. Thin varieties are glazed with spar without lime, so the products are matte, milky-creamy. But the simpler varieties are covered with a completely transparent lime glaze. Glaze and porcelain are composed of the same substances, only in different proportions. Thanks to this, they are connected and the glaze can no longer be broken off or peeled off. "

Hard porcelain is distinguished by its strength, strong resistance to heat and acids, impenetrability, transparency, conch-like fracture and, finally, clear bell sound. Invented in Europe in 1708 in Meissen by Johann Friedrich Boettger.

Soft porcelain , also called artistic or frit, consists mainly of mixtures of vitreous substances, the so-called frits, containing sand or flint, saltpeter, sea salt, soda, alum and crushed alabaster. After a certain melting time has elapsed, marl containing gypsum and clay is added to this mass. In principle, this means that we are talking about a fused vitreous substance with an addition of clay. All this mass is ground and filtered, bringing to a plastic state. The shaped object is fired at 1100-1500 ° C, making it dry and non-porous. The glaze is mainly made of glass, that is, from a fusible substance, rich in lead oxide and containing, in addition, sand, soda, potash and lime. Already glazed products undergo a secondary firing at 1050-1100 ° C, when the glaze is combined with the shard. Compared to hard, soft porcelain is more transparent, the white color is even more delicate, sometimes almost creamy, but the heat resistance of this porcelain is lower. The fracture is straight, and the unglazed part is granular in the fracture. Initial European porcelain was mostly soft, as exemplified by the beautiful and highly prized Sevres. It was invented in the XVl 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 around 1750 there. In addition to kaolin and feldspar, it contains lime phosphate from burnt bone, which makes it easier to melt. Bone china is fired at 1100-1500оС. So, we are talking essentially about hard porcelain, but one that is softened by mixing the burnt bone.

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 the shard. With the appropriate glowing heat, this glaze melts and bonds firmly to the shard. By its properties, bone china occupies an intermediate position between hard and soft porcelain. It is tougher and harder than soft porcelain and less permeable, but it has a rather soft glaze in common with it. Its color is not as white as hard porcelain, but whiter than soft porcelain. For the first time bone china was used in 1748 in Bau by Thomas Fry.

From the above, we can conclude; that the main ones for the manufacture of porcelain, there are three types that differ in composition, firing temperature and are used for different types products. Also, for each type, its own glaze is made.

PORCELAIN PRODUCTION TECHNOLOGY

... Porcelain production

The production process for the manufacture of ceramic products consists of several stages:

preparation of raw materials;

mass preparation;

product formation, firing;

glazing and decor.

Preparation of raw materials consists in purification of raw materials from impurities, thorough grinding, sieving, drying, etc. Preparation of the mass consists of mixing raw materials in certain proportions and mixing the mixture with water until a homogeneous liquid porcelain mass is obtained. The mass is passed through a sieve, cleaned (by an electromagnet) from iron impurities and dehydrated (on filter presses or vacuum presses) to obtain a molding dough.

· Free forming on a potter's wheel;

· Plastic molding by hand impression in the form;

Plastic forming in rotating plaster form using a forming template or roller;

· Forming the vessel by the method of circular molding. Slip casting into plaster molds;

· Production of ceramic products by a combination of several molding methods.

The method of free molding of ceramic products on a potter's wheel consists in the mechanical action of the potter's hands on the clay blank in the form of a plastic dough. First, the master prepares the potter's wheel for work. The first stage is the primary processing of the workpiece. Then, the inner cavity of the product, the edges of the blank, and again the inner cavity are formed. After that, the master pulls the workpiece to the desired height. During all these operations, he rotates the potter's wheel with his foot or with a drive mechanism. The process ends with finishing the outer surfaces, trimming the bottom, drying. During drying, the product can be decorated with stucco details, seals, stamped with stamps.

Plastic molding by hand impression is carried out using plaster molds. Forms can be open and detachable; open ones are used for forming flat products; detachable - when making products according to volumetric models of complex shapes.

Plastic molding in a rotating plaster mold using a template or roller occurs as follows. The mold, which opens into two halves, is assembled and installed in the rotating bowl of the machine. A lump of clay is fed into the inner cavity of the mold, calculated for the volume of the product being made. A forming template is lowered into the mold cavity, which evenly distributes the clay mass in the inner side of the mold, after which it is lifted and removed from the mold. Then the mold with the product is removed from the setting machine, dried, opened, the product is taken out and further processing is continued (attachment of parts - spouts, handles, lids and other additional mounts).

Slip casting into gypsum molds is based on the property of gypsum, to absorb moisture, and the ability of clay to pass from a liquid slip to a state of plastic dough when moisture decreases. Products are formed as follows. The slip is poured into the inner cavity of the gypsum mold, resulting in a redistribution of moisture between the slip, which gives off moisture, and the gypsum mold, which absorbs this moisture. After the redistribution of moisture on the inner working surface of the gypsum mold, a layer of clay mass is formed from the slip, which turns into a state of plastic dough. When the mold has "gained" a predetermined thickness of the clay layer, the slip is poured from the inner cavity of the mold, and the clay layer on the inner surface of the mold remains. This layer of thickened slip is a molded hollow ceramic product - raw. As it dries, the raw material in the form decreases and separates from its walls.

The manufacture of ceramic products by combining several molding methods makes it possible to obtain products of complex shapes. The combination of a plastic molding method in a rotating plaster mold with a metal template or roller with slip casting and mounting of attachment parts is widespread in the production of teapots, sugar bowls, cups, decanters, bowls and other porcelain and earthenware products, consisting of a body and individual parts. After molding, the products are dried in air and fired.

And what is porcelain made of?

PORCELAIN: The composition of which the best stone dishes are made: porcelain clay, kaolin, weathered feldspar with quartz.
V. Dahl
Over a thousand years ago, people in China drank from jade cups. They were very expensive.
After many years of searching and many failures, Chinese potters made a material that surpassed jade in its qualities, turned out to be more accessible and easier to process.
It was porcelain. For a long time it was called "imitation of jade". The "China Secret" was the secret of the raw materials. In the province of Jiangxi, there were huge reserves of "porcelain stone" - a rock consisting of quartz and mica. The porcelain mass was made from briquetted powder of "porcelain stone" (pe-tun-tse) and kaolin, which gave the product whiteness. Kaolin was abundant in the same province. The mass was "aged" for more than a dozen years, so that they acquired plasticity. The glaze was composed of several layers of different transparency, obtaining a special matte sheen.
Porcelain was used not only for dishes (the imperial court received 31,000 dishes, 16,000 plates with dragons, 18,000 cups every year), but also benches and gazebos, and in 1415 the Nanking Pagoda was built. Porcelain vessels were in China and musical instruments: tapping a thin stick on their walls gave birth to a melody.
All porcelain can be divided into three main groups - oriental porcelain, European hard porcelain and soft porcelain (semi-porcelain). The main constituent part of Eastern and European hard porcelain is kaolin (non-melting porcelain clay and feldspar). There is more kaolin in European porcelain than in eastern porcelain, and it requires a hotter fire when fired. This gives it transparency, but in such a fire all colors fade, except for blue. Therefore, European porcelain has to be painted over glaze, while oriental porcelain allows you to use a number of paints for underglaze painting.
Hard porcelain, or simply porcelain, is a homogeneous, white, strongly ringing, hard and difficult to melt, with an insignificant thickness, a very transparent mass, in a fracture, greasy, shiny, concha, fine-grained; hard porcelain consists mainly of kaolin and feldspar mixed with quartz, lime, etc., and is covered with hard glaze.
Soft porcelain consists of not completely melted, glassy, \u200b\u200bfine-grained mass, with lead, crystal-like, siliceous glaze. The fusible glaze, making it look like Chinese porcelain, allows for thick writing and much softer tones than hard porcelain. The English soft porcelain (bone china) contains burnt bone, phosphate salts, kaolin, etc. It occupies a place between the stone mass and hard porcelain, resembles white alabaster and is extremely transparent.

Porcelain is the finest ceramics of white translucent color with a bluish tint, used for sculpting tableware and sculptures.
It has a second name "singing dishes", hitting the edges of which, you can hear a melodic ringing, as if thousands of bells are hidden at the bottom.
Nowadays, such products are objects of good taste, an attribute of luxury, they are always "timeless classics" that make an impression not only as a table setting item, but also have a great value.

The basis in the production is porcelain mass, consisting of koalin clay, feldspar and quartz.
Due to the high temperature regime of firing, the material becomes dense, without pores. Products acquire thermal strength and at the same time lightness, do not have smudges and seams.

The origin of porcelain is China.
During the reign of the Tang dynasty of the 6th-7th centuries BC, dishes were made mainly from jade, which was considered a rather rare and expensive stone, and cheap clay and wood were short-lived.

It took several decades until a rock formed from quartz and mica, called porcelain stone, was found in Jiangxi province.
The first items were elongated jugs with embossed decor in blue and greenish tones.
In the 9th century BC, China unofficially became the "porcelain capital".
Mass production of tableware and export to Europe and East Asia begins.
The secret of production for many centuries was kept in the strictest secret, which the German chemist Boettger managed to reveal.
Thanks to the deposits of white clay in the vicinity of Saxony, he made a cup and presented it to King Augustus the Strong.
From that moment on, "Saxon porcelain" began to sound. The secret was revealed.

Classification

There are three types of porcelain: hard, bone and soft.
They differ in the main components and firing temperature conditions.
The production of porcelain began precisely with the hard look.

Hard porcelain

It consists mainly of a large part of koalin and a smaller part of feldspar, to which quartz and sand are added. Thanks to this proportion, the cookware has good strength, value and popularity in production.
Double fired. First, at a low temperature of 900 degrees, then when applying the glaze - 1350-1450 degrees.
Moreover, each stage undergoes strict quality control. Sometimes exceeding the marriage threshold of 20-25%.
This type of porcelain has several purposes:

household - tea room, dining room and kitchen utensils;
artistic - vases, figurines, bas-reliefs, dishes;
industrial - electrical insulating materials;
chemical - glassware, details for the chemical and perfumery industry.

Bone china

Intermediate, it is considered much more valuable than hard porcelain. It is obtained by adding bone ash to the bulk.
It is also subjected to double firing, but first at a high temperature of 1200-1300 degrees, then the temperature is gradually reduced for better hardening to 1050-1100 degrees. Due to this, it has complete absence since.
Products are distinguished by a special white color and belong to the elite category.

Soft porcelain

As a result of attempts to create an analogue of the hard type of ceramics, it was first invented in Europe.
The products are creamy. Consists of sand, saltpeter, crushed alabaster and clay.
It undergoes a one-time heat treatment at 1050-1100 degrees. The ceramic mass is not completely sintered, because of this it has a porous surface, low heat resistance, high sensitivity to temperature changes, the glaze is easily exposed to mechanical stress.
Used in the production of art products.
This porcelain has several types.

French is very similar to Chinese. Perfect for painting and painting with gilding interior items.

English - due to the addition of phosphoric acid salt to the composition, it has a structure similar to white alabaster. Ideal for gemstone work.

German - consists of clay, externally and in quality is close to glass. Due to the low firing temperature, painting with paints acquires a beautiful shine.

To obtain the desired surface shape and use different ways decoration, several varieties of soft porcelain are used.

Feldspar - contains in the base a high content of feldspar 50%, quartz sand - 20% and white clay - 30%. It goes through one stage of thermal firing, due to which the material has a high density. Differs in heavy weight, low strength and low cost. Convenient when painting products.
High-feldspar - has a difference in high quartz content of 45% and feldspar 40%, the least amount of clay - 15%. Due to such proportions, it belongs to the category of elite.
Just like feldspar porcelain, it is subject to low firing temperatures, which open up great possibilities for decoration.
Frit is one of the most inexpensive types of ceramics.
Due to the addition of a salt-glass alloy (frit) to the clay, the lowest possible firing occurs. It has mechanical strength, heat resistance and a high degree of protection against chemical attack.
It is widely used in sculpting compositions.

Biscuit porcelain

Another type of porcelain, the main difference of which is that it has passed only the primary firing at a temperature of 800-1000 degrees. This results in a rough porous structure. The material is more reminiscent of high-quality marble in structure. Most often, the biscuit is not covered with glaze, leaving a matte surface resembling velvet leather. The birthplace of biscuit is the French town of Sevres. The first masters began working in this technique in the second half of the 18th century. For the reason that porcelain is not protected by glaze, it is not used for the production of tea and dining sets. It makes magnificent figurines, vases, sculptures and furniture decor elements.

For more than one century, porcelain dishes and interior items have distinctive features in the painting technique.

Underglaze painting is a rather complicated and time-consuming painting and expensive.
Typical mainly for Chinese antique porcelain. The drawing is applied with a pen or brush before firing, so the master needs to accurately calculate the proportions of dyes and paints to avoid dissolving the drawing in the glaze. Be sure to add aluminum oxide or kaolin.
This technique also uses spray guns and special underglaze pencils.
Overglaze is the simplest painting in a product, making it affordable.
Paints must have thermal and chemical resistance, since after being applied to the glazed surface, they are fired in a muffle furnace.
This painting is most often used in the design of services.

Decor

These can be mini-figures of people and animals, flowers, curls, elements of church symbols and much more.
Individual elements, also made of porcelain, are fixed with adhesives.
Thanks to such additions, the products acquire an exquisite look.
The dishes become more elegant and fragile.

Conclusion

Porcelain will forever remain associated with history, tradition and art.
It is no coincidence that it is called "white gold".
It is an ageless value that can be preserved for centuries and passed on for generations.
Nowadays, there are many factories for the production of porcelain, not only in Russia, but also abroad.
Porcelain products are able to create warmth and comfort in every home.

The production of porcelain is a delicate art, chemistry, magic, it is not for nothing that the material is called "white gold". There were times when tableware made of it was valued more expensive than precious metals, was considered the privilege of crowned persons.

History of appearance

The secret of the production of porcelain has long been a mystery. The birthplace of the material is China, where it appeared in 620. For almost a thousand years, Chinese craftsmen remained monopolists, carefully guarded the recipe and the secret of making kaolin products.

Meanwhile european masters experimented to get the optimal formula. As a result, in 1708, two German scientists succeeded - Bettger and Chirnhaus. They managed to obtain quality raw materials for porcelain. Thus began his era in Europe.

In the same 1708, the first manufactory was opened in Dresden, which was engaged in the production of unglazed cutlery. Two years later, the craftsmen presented the products to the German king - he approved them. And soon German sets conquered other countries.

A detailed description of raw materials and technology appeared later, after 20 years. Gradually, production was mastered in France, England, Russia.

Description

In the classic version, this is a translucent material, thin glazed ceramics. Its characteristic features:

white with a blue tint;
high strength - it will not work to scratch the product with a sharp object;
low porosity;
resistance to chemical and temperature effects;
natural beauty.

Composition and preparation of raw materials

For the manufacture of porcelain, a mass is used, which includes:

50% kaolin;
25% quartz;
25% feldspar.

With such proportions, the mixture turns out to be white, with the required degree of transparency, plastic. Not every clay is suitable - only certain varieties.

The preparation of raw materials is necessary in order to break down natural solid materials into the smallest granules and obtain a homogeneous mass. To obtain a uniform composition, plastic kaolin is dissolved in water using stirrers with paddles.

Then the previously prepared mass (it has the consistency of a suspension) is sifted through industrial sieves. Each sieve has 3500-5000 holes per 1 cm 2. An electric magnet is built into them, which cleans the mixture from large metallic impurities.

Feldspar and quartz are cleaned of impurities, after which they are fired in special furnaces. The firing temperature is 900-1000 degrees. In the process of heat treatment, quartz cracks, it is easier to grind and clean from iron compounds.

Removing iron is a mandatory step, because if this is not done finished products there will be a dirty brown tint.

For the finest grinding possible, special additives are added to industrial mills. They are superficial and do not affect the quality of porcelain products.

When a homogeneous mass is obtained, it is sieved again, then dehydrated in filter presses and sent for aging. The raw mass is cured in damp rooms for two weeks. During this time, it loosens, its plastic properties increase. Then, air is removed from the raw material in vacuum presses and sent to form blanks.

Molding

Porcelain production technology is a complex multistage process. This largely explains the high cost of the products. Plaster or PVC molds are used to mold blanks.

Forming is carried out in a semi-automatic or automatic way. A special roller and a rotating mold are used to roll out a layer of the same thickness.

Items of complex shape, having decorative and artistic value and complex configuration, are made by casting. For blanks, plaster or split forms are used.

Drying

When the future cup, vase, teapot, plate are formed, they need to be dried. The initial moisture content of the raw material is 22-24%, and after drying the indicator is reduced to 2-4%. This is necessary to obtain durable products, without internal cracks and deformation.

Drying consists of two stages:

Preliminary - the workpieces are dried in molds up to 15-16% humidity, after which they are removed from the molds.
Final - the workpieces are dried without molds to 2-4% moisture.

Processing is carried out in special dryers, which significantly speeds up the process. Dried kaolin products are cleaned from seams, removed dirt, dust and sent for firing.

Burning

The first firing is carried out at a temperature of 900 degrees and takes about 12 hours. Then the product is covered with glaze and fired again.

The re-firing temperature is higher, it starts from 1000 degrees - the exact figure depends on the type of porcelain and the technique of its production.

Types of porcelain

The material is classified by manufacturing technique as:

solid;
soft;
biscuit;
bone.

Solid

It contains from 47 to 66% kaolin. Firing takes place at a temperature of 1400-1600 degrees. Initially, there is less moisture in such raw materials - the workpieces practically do not deform.

Bone

This type is considered the most durable, while it is valued for its thin, translucent walls. With an apparent external fragility, it is more difficult to break it than the classic one.

Half of the composition of bone china is bone meal - hence the name.

Biscuit

Biscuit porcelain has a porous, rough structure that looks like marble. This feature is explained by the fact that the workpieces undergo only primary firing at temperatures from 800 to 1000 degrees.

The matte texture looks so impressive that it is usually not covered with glaze. This technique is used to make vases, figurines and other interior items. Biscuit china is not made.

Soft

The composition of soft raw materials contains less kaolin - 25-40%. At the same time, the amount of feldspar and quartz is increased - 45 and 30%, respectively. The kaolin mass turns out to be not so strong, but very plastic.

There are several varieties of soft china:

Feldspar. It contains 50% spar and only 30% white clay. The material is dense, heavy, but not durable, therefore it is much cheaper than analogues. It is fired once.
High feldspar. It differs from feldspar in a large amount of quartz - 45%. Specific gravity clays - only 15%. Products made from it are considered elite, they are fired at a low temperature.
Frit - durable, resistant to thermal effects, chemicals, affordable. Fired at the lowest temperature. In addition to clay, the composition includes alloys of salts and glass. Frit mass is often used to sculpt figurines and other original things.

Soft kaolin mass was preferred by craftsmen Ancient China, and hard - European craftsmen.

Painting

There are two types of painting: underglaze and overglaze.

With underglaze painting, first paints are applied to the product, and then the painted layer is covered with glaze. The glaze is transparent, gives an elegant shine to products, protects against microcracks, ultraviolet radiation, and alkalis. These dishes can be washed many times without compromising quality.

The overglaze technique is performed in the reverse order: first, the product is covered with glaze, and paint is already applied to it. The colors are bright, saturated, but eventually fade and fade.

For sets and accessories of mass production, the drawings are applied using the decal technique. First, the drawing is printed on special paper, then it is glued onto a cup, tureen, plate and fired. The paper burns out and the paints are imprinted on the surface of the dishes.

Premium-class porcelain is a piece product; craftsmen paint it by hand, decorate it with gold and silver. The cost of the work is high, but real works of art are obtained.

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