الخزف ( السيراميك ) ١ _ a , من كتاب تكنولوجيا التصوير , د.م محمد حماد

- Porcelain (ceramic)

General word:

Porcelain or ceramico ceramic is glazed pottery and is made from clay or clay that is fired and pottery is... After painting it, porcelain is produced. Therefore, porcelain is a malleable raw material, as it can be shaped and used for several purposes. From utensils and dishes to small art paintings and figures, it can also be used to produce mosaic panels consisting of small pieces that are assembled and colored in the shape of the required design, and make huge wall panels that are fixed on the internal or external walls, so they resist weather fluctuations in cold and heat

The Egyptian knew the art of ceramics after the first attempts, which were in the form of primitive pottery since ancient times, as he used the clay found on the banks of the Nile and made various utensils from it to preserve his food. with sufficient rigidity. Since that time, man has gradually diversified his production in this section and decorated his artefacts with motifs that are consistent with his renewed culture to this day. So we see in the antiquities of ancient Egypt pottery vessels with distinctive lines with simple, innocent motifs, as we see in the antiquities of “Tutankhamun” the (alternative) Oshini statues painted with turquoise glass materials, which is a rare color that humans did not reach to produce something similar until very recently. They were in those historical days in Badawon planning to bring out the required color from the beginning of the installation of the clay, so they would give the body of the clay the appropriate atmosphere of raw materials that help show the vessel or the statue in the required color ... Then it continues in the steps of the work stages by burning, glazing, and then burning again until the piece looks like in the required color.

The main materials in the composition of Egyptian ceramics are aqueous aluminum wires with a small percentage of foreign materials, such as iron oxide, sand, mica, soda, potash, manganese, and calcium carbonate. Natural pottery tends to be gray or pale yellow, but it may also have a slight red color, and this redness is always due to the amount of iron compound in the clay... This compound turns into iron oxide when the clay is exposed to heat after being placed in it.
Qarn al-Hariq, and the Egyptians used the aura for this purpose: because the aura is nothing but a natural mud of iron oxide.

In addition to the Egyptian interest in colors, he was also interested in making the shiny glass layer on the surface of pottery vessels, which is what the glass industry developed after that, and this step is considered one of the greatest industries invented by the ancient Egyptians for the benefit of humanity.

And he mentions - Birsh » Birsh The pottery industry originated from white sand, and it was melted a little and then covered with colored glaze. We do not, in fact, consider the Egyptian Chinese as a type of Chinese, but rather a type of faience.

As for the colors used by the Egyptian, they are standing blue, light or greenish, and it appeared from their analysis that they are copper compounds, which gave the blue color, and cobalt compounds were also used since the eighteenth dynasty. As for the green color, its color is due to the compounds of copper and iron, and the yellow color is due to antimony with lead... As for the black color, it is due to the presence of copper and manganese or a large proportion. new from

The art of ceramics continued here in Egypt in the Coptic era, influenced by ancient Egypt, as it is an extension of the Pharaonic era, and it also continued in the Islamic era, the manufacture of ceramics with a beautiful distinctive character, which is characterized by geometric motifs derived from abstract nature, according to Islamic traditions that prohibit human drawing. Pieces of this ceramic were found covering the walls of some ancient houses. One of the characteristics of Islamic ceramics is their use of a beautiful metallic luster, by giving their kilns a reduced atmosphere, and by using a mixture of silver and copper oxide, or either of them, over the coatings after leveling them... provided that the temperature of the kiln is adjusted as needed; If the temperature is higher than required, the color mixes with the paint and loses the effect of the metallic colors. And you can see in metal ceramics one of the great innovations that the Arabs found in the Islamic era, and it was made in the Arab East and in Egypt in Fustat factories. As for the colors that were used in this era, the white ones depended on mixing them with sure tin, the green ones depended on copper, antimony or lead, the yellow ones depended on antimony, lead and iron, the light yellow ones depended on lead and antimony and a little table salt and potash, and the purple ones depended on manganese, and the blue color So he was working

from cobalt

In modern Egypt (at the beginning of the thirties), there were no ceramic and pottery works in the industry except for zeer, salas, qulla, and similar drinking vessels, as well as glazed vessels such as pots, tagines, brams, and the like. There were no ceramic works made of artistic ceramics... until it appeared The Department of Ceramics in Applied Arts The first Egyptian artists to study it was Professor Mahmoud Saber, who traveled on a mission to study ceramics at the expense of
The late Ms. Hoda Shaarawy. And Mr. Saeed Al-Sadr came after him in 1934, and he is rightfully considered the founder of the School of Ceramics in Egypt, and most of those who work in ceramics today in Egypt are students from him... The first of them to work in the field of artistic ceramics since his graduation in 1938 until now is the artist, Professor Hassan Heshmat, who took raw material Porcelain is a material for producing his beautiful artwork that bears his distinctive Egyptian fingerprints

In 1953, the example, Mr. Fathi Mahmoud, turned to the ceramics industry and opened a factory to produce works of art. The General Company for Porcelain and Porcelain Products was also established, and its factory began production around 1960.

Materials needed:

The materials needed for ceramic works are the colored glass materials whose elements agree with that layer, the brushes needed for coloring or the airbrush, and then the firing furnaces needed for this purpose, and we explain them as follows:

1- Tine:

Aswan slurry is usually used, with a density of 2.29, and it is composed of 48.62% wire, manganese 8.41/8, lime 5.85, iron and manganese 56 11, bromine 17.57, sulfuric acid 3.18/ and humidity 8.41.

Before using the mud, it must be purified, by soaking it in water, so it can be turned into a liquid that is filtered in a fine strainer.... However, despite that, some foreign materials remain integrated into the mud and are not visible to the naked eye. There are several ways to purify the mud other than the filter, through running water Slowly, it carries with it the pure mud and the bad sedimentation with impurities. . This method is used in large factories. It should be noted that the clay must be soaked in water for about a week to disintegrate and absorb a larger amount of water and become more suitable for shaping after kneading it. It can be shaped by hand, by wheel, or by casting

Colored glass materials:

Its base is kaolin, quartz, feldspar, lead oxide and borax in varying proportions with the required degree of burning, then oxides are added to it that give the required colors such as:

Tin oxide .... gives a white color

White titanium oxide gives a white color and helps to fade and lack of luster. Zinc oxide .... It gives a white color if used in a large proportion and helps with luster.

Antimony oxide ... gives a bright yellow color
Yellow titanium oxide gives a yellow-brown color and helps

On the dark.

Uranium oxide.... gives an orange-red color, vermilion iron oxide... gives a honey-brown color, reddish-brown, and participates in the extraction of black. Nickel oxide ... gives a gray color. Bismuth oxide ... gives a golden aubergine red color when reducing the paint. Cobalt oxide gives the blue color and participates in producing the black color.

. Copper oxide manganese oxide black color. It gives a turquoise and metallic green color, gives a violet and brown color, and participates in excretion

Chromium oxide gives olive green and red color. Silver oxide... It gives silver when the paint is reduced.

We notice that some oxides give different effects to the compositions, helping to increase or decrease the luster of the composition, and some of them increase the transparency of the composition or make it opaque. Also, the temperature difference may affect the composition and change its color, as well as the shape of the kiln has a special effect on production... If we burn the glazed colors that contain copper oxide in an open kiln, the green color can be obtained first, and if the fire increases, it turns red .

We also note that the oxides, if mixed, may affect each other... Therefore, we must learn about the effects of colors on each other before mixing and using them in coloring and glazing... Also, the strength of the oxides' tolerance to heat varies, and therefore this point must be taken into account in the fire to stabilize the temperature The temperature is at the appropriate degree for the nature of the required colors.

Brush and airbrush:

It is felt to use soft types of brushes, such as those made of natural squirrel hair, marter, or goat hair brushes that were used in the past. It is also possible to use an airbrush on large surfaces and print drawings by stamping or silk screen.

Ovens:

The types of ceramic and pottery fire ovens differ in terms of their design, so we find some of them with a reductive fire box, and some of them are ovens without a fire box