WO2000006513A2

WO2000006513A2 - Resistant porcelain against heat changes

Info

Publication number: WO2000006513A2
Application number: PCT/TR1999/000031
Authority: WO
Inventors: Nafi Güral; Mehmet Karaova
Original assignee: Gueral Nafi; Mehmet Karaova
Priority date: 1998-07-28
Filing date: 1999-07-23
Publication date: 2000-02-10
Also published as: EP1028925A2; WO2000006513A3; HUP0003889A2; KR20010024310A; CN1274340A; BG104306A; PL340267A1; AU4951499A; JP2003520174A

Abstract

The subject of the presented invention is porcelain used as a house-effect that has a special rational composition of raw materials and resistant against sudden and high graded heat changes and in form of a dish which filled with liquid and placed on heat source with flame there is no fracture, crack and deformation.

Description

DESCRIPTION

RESISTANT PORCELAIN AGAINST HEAT CHANGES

Background of the invention

By using stone and soil as raw material, dish manufacturing is one of the world's oldest industrial branches. Up to now, different kinds of ceramics like china, porcelain etc. were manufactured by using different raw materials and different methods of manufacturing. In now a days technology, porcelain is intensely used both as consumer goods (ex: house-effects etc.) and in various industrial fields.

The porcelain, which is used as house-effect, is manufactured by using various kinds of raw materials, but since centuries there has been no change in its use. Changes occurred mostly in the shape of the products but their functional features remained the same, like plates where food is put in or cups liquid drinks are filled in. The porcelain, which is used as house-effect, is only a means for serving the cooked meal. For example, tea is prepared in teapots, in which water boiled in another cup and poured together with tea and also used for serving. The most important reason for using the porcelain for the mentioned purposes is because of health. The most important feature is the coating on the porcelain, called glaze. Due to this impermeable material there is no environment in the porcelain dishes that let the bacteria live which threats the health of humans. There is no danger for the health that may be caused by the reaction between the chemicals in the cleaning stuff and the glaze. Because of this reason porcelain remains as the most preferable house-effect.

Cooking means are manufactured from various materials. The most frequent used materials are metal or metal alloys. Because of they are good heat conductors and their resistance against heat and fire, they are preferred as cooking means. However this sort of materials may have many negative features. For example, cooking means made from metal loose heat very fast and the food that is in it cools earlier than expected. On the other hand, metal reacts with chemicals that may be in the meal or with chemicals that constitute the raw material of the cleaning stuff and may threat the health of humans. Since there are no other alternatives metal cooking means are still being used.

The aim of presented invention is to create an alternative to the metal cooking means. The main characteristic of the invention is that it carries out all the functions of the metal cooking means and eliminates the negations of the metal cooking means. On the other hand, the aim was to develop a cooking means made of porcelain that the production cost is below than the metal ones, hygienic, worth of quality, can cook more delicious food, uses less energy while cooking than their alternatives and is the most ideal environment for cooking.

The feature of the presented invention is that it is resistant against heat changes of high rate. Porcelain, which is generally used as house-effect is not resistant against heat changes of high rate. When porcelain, is in a form of a cooking dish, is placed directly on fire or on another heating source and get touch with high graded heat, it cracks or fractures. Today's technology has no product made completely out of porcelain, which can be used, for cooking. Up to now, the products developed for cooking are covered with asbestos at their bottom, where it get in touch with fire or heat, in this way it becomes resistant against heat changes and high degree heat. However, using asbestos to this purpose cause danger for health, because there are negative effects in its structure. It's well known that asbestos cause pulmonary cancer. It can be taken a lot of precautions; nevertheless, it is clear that using such dangerous stuff for cooking may cause fatal diseases.

The presented invention has no negation in its body with the consideration of human health like the metal dishes and asbestos covered porcelain. A porcelain which is resistant against high graded heat changes and heat sources with or without flame, that is, if it comes in contact with heat sources working with natural gas, liquid petroleum gas or electricity, there is no crack or fracture, this kind of porcelain is manufactured by using the production methods and the raw material mixture according to their rational composition, which are described below. Description of the invention

Porcelains that need different features according to its purpose of use, are gained these features by changing the used raw materials or by using the same raw material in various rational compositions and different kinds of manufacture methods are applied. By using the same manufacture method and changing only the raw material rational composition, a different kind of porcelain can be obtained.

The basic feature of the presented invention is that when it is in a form of a dish filled with liquid, it shows resistance against sudden and high degree heat changes. The contact with heat may not only be with fire but also with other heat sources where it shows the same resistance. For example, on the flame of heat sources working with natural gas, there was no result such like crack, fracture or deformation. There was also no problem with microwaves and cookers heated with electricity.

The dish which could be put liquid in it was produced according to the described below and presented invention rational composition of raw material mixture, filled with water and frozen in deep freeze, then the dish placed on heat with frozen water in it, waited until it reached to the boiling temperature, but there was no result like crack, deformation or fracture. After the water started boiling, the dish kept on fire and waited the water in it vaporized completely, but there was again no fracture, crack or deformation.

The same experiment was made by putting oil in dish, which was produced according the presented invention; there was again no fracture, crack or deformation.

The field of usage of the presented invention, not limited with the followings, due to its features mentioned above, it can be used for any kind of cooking means and for industrial fields needs porcelain with the features of the submitted invention that resistant sudden and high degree heat changes.

The porcelain which is resistant against sudden and high degree heat changes and does not loose its physical, mechanical, chemical and electrical features by such heat changes, the rational composition of the raw material mixture will be explained in detail by the help of the Figure 1.

Porcelain carrying the features of the presented invention was manufactured with a mixture prepared according to the rational percentage in the field between the A, B and C points given in the rational composition system of feldspar, kaolin and quartz in Figure 1.

Detailed Description of the invention

Raw materials generally used in production of the porcelain, 5-10 percent feldspar, 60- 75 percent kaolin and 20-30 quartz are used for the mud of porcelain Table 1. The method used in manufacturing same as the normal household porcelain, the mud prepared with the raw material mixture of the presented invention is given shape on a lathe or by casting. After the shape is given, the semi-manufactured product will be dried in order to remove the water in its body.

Table 1: Percentage of rational mixture of the raw materials

Feldspar 5 - 10 Kaolin 75 - 60 Quartz 20 - 30

The dried products that became semi-products are put in the porcelain kiln for the primary bake for 22-24 hours at a degree of 950-1050 centigrade. After this process, the semi-product is glazed with the spitting and dipping method.

The glasslike layer that covers the porcelain body and after the porcelain became cold it bonds to the porcelain by chemically and physically, is called glaze. Glaze covers the whole porous surface of the porcelain body, so that water or any other liquid can not reach the porcelain body. The composition of the glaze and the composition of the porcelain have to be concordant. Because of this reason every kind of porcelain has a different method for preparing glaze composition.

The glaze composition used for the presented invention is given in Table 2. The segger formulation interval of the said glaze is given in Table 3.

Table 2: Glaze composition interval (percentage)

Feldspar 10 - 16

Kaolin 12 - 8

Quartz 45 - 55

Marble 7 - 13

Dolomite 8 - 3

Table 3: The segger formulation interval of glaze

NaiO 0,050 - 0,090 AI2O3 0,500 - 1,000

K2O 0,100 - 0,150 Fe2θ3 0,005 - 0,010

CaO 0,450 - 0,900 SiO₂ 5,000 - 10,00

MgO 0,080 - 0,130 TiOi 0,001 - 0,003

After the application of glaze, the semi-product is put in the kiln again and baked 24 hours at 1340 - 1350 degrees centigrade in order to bake the glaze.

The production method explained above is used for the manufacture of cooking means which are used as house-effect and is given as examples to explain the invention in details. In the other fields of usage of the invention especially in industrial fields may different production methods be able to be applied. When the raw materials feldspar, kaolin and quartz that bring the content of the invention into existence, have good quality, the result will be better. When the mixture given in Figure 1 and the mentioned raw materials given in Table 1. Are used according to the given rational composition limits and by applying the above described process, the embodiment of submitted invention, porcelain that is resistant against high and sudden heat changes, will be reached.

Claims

Claim 1. Porcelain dishes that can be placed on heat source with or without flame and is resistant against high graded and sudden heat changes, which raw materials rational composition are feldspar 5 - 10 percent, kaolin 75 - 60 percent and quartz 20 - 30 percent used in preparing for the mud of the porcelain, after giving the shape to mud as a dish, the moisture in it dried; then, it is put in kiln for the first baking at 950 - 1050 centigrade for 22-24 hours; between constrains of the glaze formulation and segger formulation given in Table 2 and Table 3, the product glazed using the known methods; the glazed product put in the kilns for the secondary baking at 1340 - 1350 centigrade for 24 hours and obtained a porcelain dish in which food or such things are put in it and can be placed on powerful heat sources with or without flame and there is no fracture, crack or deformation.

Claim 2. The porcelain according to claim 1 characterized in which can be placed directly on heat source with or without flame and is resistance against high graded and sudden heat changes and percentage of rational composition of the raw materials are feldspar 5 - 10 percent, kaolin 60 - 75 percent and quartz 20 - 30 percent and shown in the area which is between the points A, B and C in Figure 1.

Claim 3. The porcelain according to claim 1 characterized in which can be placed directly on heat source with or without flame and is resistance against high graded and sudden heat changes and the method of production that is; shaped as a dish from the mud obtained by using the raw material mixture as described the in claim 1 , first dried to remove the moisture, then put in the kiln for first baking at 950 - 1050 centigrade for 22 - 24 hours and glaze in the semi product by using the known methods with the glaze according to glaze and segger formulation given Table 2 and Table 3, and put in the kilns again for secondary baking at 1340 - 1350 centigrade for 24 hours.

Claim 4. The porcelain according to claims 1 to 3 characterized in which can be placed directly on heat source with or without flame and is resistance against high graded and sudden heat changes and percentage of rational composition of the raw materials are feldspar 5 - 10 percent, kaolin 60 - 75 percent and quartz 20 - 30 percent and using the method of production such as; shaped the mud obtained by using this mixture, first dried to remove the moisture, then put in the kiln for first baking at 950 - 1050 centigrade for 22 - 24 hours and glaze in the semi product by using the known methods with the glaze according to glaze and segger formulation given Table 2 and Table 3. and put in the kilns again for secondary baking at 1340 - 1350 centigrade for 24 hours and using the porcelain in other fields suitable to its characteristics of resistance to sudden and high grade heat changes.