Making Ceramic Coffee Mugs - Solid and Hollow Grouting

Xinxiang ceramic mug manufacturer Co,. Ltd, Some of the commonly used ceramic coffee mugs are made through a grouting process. Which ceramic coffee mugs are produced by grouting and which are produced by roller pressing? In general: mugs with complex shapes, such as irregularly shaped mass-produced ceramic coffee mugs, are mostly produced by grouting; regular shaped cylindrical coffee mugs, most of which are produced by roller pressing. Of course, there are exceptions. For example, the thinner cylindrical shaped ceramic coffee mugs, there are also produced by injection molding. In fact, many coffee mugs are a combination of both production processes. For example, we commonly use ceramic mugs with handles, where the mug is made by roller pressing and the handle is made by grouting. Roller pressing is relatively simple, and today we will explain the production process of grouting.

Grouting process is the use of gypsum mold absorbency, will have the mobility of the mud into the gypsum mold, so that the mud dispersed adhesion in the model, the formation and the model of the same shape of the billet layer of mud, and with the extension of time and gradually thickened, when it reaches a certain thickness, by drying and contraction and detached from the mold wall, and then take out of the mold, the billet system is completed. Grouting process is divided into: hollow grouting and solid grouting.

1. Hollow grouting

Hollow grouting is the use of gypsum model one-sided suction pulp and the formation of products, the thickness of the blank depends on the mud in the model to stay in the time, generally applicable to the injection system pots, mugs, jars, bottles and other hollow vessels or figures, toys and other artistic bone china. With this method of injection into the body, the shape of the injection depends on the shape of the model work surface. The operation process is: first of all, the model work surface of the dust or dry mud clean, assembled model. The moisture content of the model should be maintained at about 5%, too dry and too wet are prone to cause defects in the blank. Grouting its into the slurry speed should not be too fast, should make the model of the air with the injection of slurry and exhaust away. Mud filled model, after an appropriate period of time, so that the adsorption in the mold wall of the mud layer to reach the required thickness, and then pour out the excess mud. Then when the blank hardens and leaves the mold, it can be removed. In order to prevent deformation of the product, the need to thicken the bottom, you can take the second grouting, that is, first injected a small amount of mud at the bottom (commonly known as “foot”), to be slightly dry, and then all the mud filled, and then operated in accordance with the above process.

Hollow grout used in the mud, its specific gravity is generally smaller than the solid grout, about 1.6-1.8. fluidity is generally 10-15 seconds, the consistency of about 1.1-1.4.

In order to speed up the formation of blanks, improve the quality of products and production efficiency, many porcelain factories have adopted centrifugal grouting, and on the basis of the use of photoresistor control, composed of mechanically operated grouting forming assembly line. Centrifugal grouting operation, is to inject mud into the rotating gypsum model, under the action of centrifugal force, so that the mud close to the mold wall, dewatering the formation of blanks. Due to the lightness of the air bubbles in the slurry, when the model is rotating, most of them are concentrated in the middle, and finally ruptured and disappeared. Using this method of injection into the body, the thickness is more uniform, not easy to deform.

Centrifugal grouting slurry used, the size of its solid particles should not be too different, otherwise the coarse particles will be concentrated in the interior of the body, while the fine particles are easy to concentrate on the surface of the model, resulting in uneven organization, uneven contraction. The speed of the model should depend on the size of the product, large products should be slow, small and medium-sized products can be faster, generally 460-540 rpm. If the rotational speed is too slow, it is easy to appear mud grain.

2. Solid grouting

Solid grouting using two gypsum mold surface (model and mold core) between the cavity, mud by the model and mold core of the working surface of the two sides of the water absorption and the formation of products, it is also known as double-sided grout absorption method. Generally used for injection of cups and spoons, fish plates, duck ponds, juice bucket and other shaped products or porcelain plate, can also be injected into the two sides of different shapes and patterns or large, thick-walled products, the thickness of the blank by the model and the cavity between the mold core size to decide. Operation, will be injected into the mud between the model and the mold core, to be most of the water in the mud by the gypsum mold absorption, the blank contraction away from the mold, at this time you can uncover the model, let the blank in the mold core to dry, until the blank in the basic exclusion of water after the blanks, and then take out the blanks. In order to facilitate the grouting of air discharge, must be reserved in the model of the air release pathway.

Solid grout slurry than hollow grout slurry specific gravity, generally between 171.9. The consistency is also higher, and the fineness can be coarsened appropriately. As the model from two directions to suck out the water in the mud, so near the mold wall of the body is more dense, the center part of the body is more loose, the uniformity is not ideal.

In order to speed up the injection of the body into the speed of the body to promote the structure of the body dense, to prevent the plaster mold on both sides of the slurry caused by the body delamination, resulting in cracking, blistering and other defects occur, so many porcelain factories switch to pressure grouting, will be placed in a bucket of slurry to raise the position of the use of slurry to increase the pressure of the slurry bit of energy. There is also the use of compressed air to increase the mud pressure, that is, compressed air pipeline grouting.

Pressure grouting slurry pressure, should be based on the shape and specifications of the product (size and thickness), generally should be controlled in 500-800 millimeters of mercury column, the minimum should not be less than 300 millimeters of mercury column. Practice has proved that increasing the pressure of mud, can improve the strength of the billet ring, reduce porosity, but must pay attention to the model of the reinforcement and close, otherwise prone to rotten mold and run pulp phenomenon.

Production of different requirements of ceramic products, China Ceramic Mug Manufacturers technical engineers will choose hollow grouting or solid grouting. These two ways in addition to the mold is not the same, using two ways of mud is also different. The key point is the difference between the liquidity of the two types of slurry. What determines the fluidity is a substance called diluent. We can understand that it is like the role of water in coffee. The more diluent there is, the more fluid the mud will be; conversely, the less fluid it will be. This is the same type of mud used in the common ceramic coffee mugs that we see when the handle is bonded to the mug.

Is it safe to microwave ceramic mugs and plates?

Xinxiang custom ceramic mug manufacturer co.,ltd, In our daily life, we often come across the microwave heating, ceramic mugs, ceramic plates can be used? To get an accurate answer, then we have to analyze the raw materials, production process and the characteristics of ceramic products. Most of the ceramic products (ceramic coffee mugs, ceramic plates) is suitable for microwave ovens. Of course there are exceptions exist.

To get an accurate answer, then, we have to first understand the working principle and characteristics of microwave ovens.

1. The working principle of microwave oven

Microwave oven is the use of food in the microwave field to absorb microwave energy and make their own heating cooking appliances. In the microwave oven microwave generator generated microwaves in the microwave oven cavity to establish a microwave electric field, and take certain measures to make this microwave electric field in the oven cavity as uniformly distributed, the food into the microwave electric field, by the control center to control the cooking time and the intensity of the microwave electric field, to carry out a variety of cooking processes.

In layman's terms, microwave is a high-frequency electromagnetic waves, which itself does not produce heat, in the universe, nature, there are microwaves everywhere, but the existence of nature's microwave, because the dispersion is not centralized, so it can not heat the food. Microwave oven is the use of its internal magnetron, the electrical energy into microwaves to 2450MHz oscillation frequency penetrate the food, when the microwave is absorbed by the food, food within the polar molecules (such as water, fat, protein, sugar, etc.) that is attracted to the speed of 2.45 billion times per second of rapid oscillation, the macro-expression of this vibration is the food is heated.

2. Three characteristics of microwave ovens

1). Reflectivity. Microwaves touching metal will be reflected back, so the use of specially treated steel plate made of the inner wall, according to the microwave oven wall caused by the reflection, so that the microwave back and forth to penetrate the food, to strengthen the thermal efficiency. However, the furnace shall not use metal containers, otherwise it will affect the heating time, and even cause the furnace discharge fire.

2). Penetration. Microwave penetration of general ceramics, glass, etc., so the common utensils used for microwave cooking. Glassware should use high-temperature glass material, low-temperature glass is not suitable for microwave heating utensils. Most of the daily ceramic products can be used for microwave oven. For example: ceramic plates, ceramic bowls, ceramic mug supplier and so on. But with gold, silver, and plastic accessories of ceramic products, can not be used as microwave heating utensils. The gold and silver edges in ceramic products are real metal, which will cause harm in the high temperature of the microwave oven. As for plastic fittings, most of them are not heat resistant and are not suitable for microwave oven.

3). Absorption. Various types of food can absorb microwaves, resulting in molecules within the food through oscillation, friction and heat. However, the degree of penetration of various foods depending on its quality and quantity of size, thickness and other factors vary.

We know how the microwave oven is heating food, then ceramic products are suitable for it? Then we also have to understand what the raw materials of ceramic products; raw materials have what characteristics; in the production of ceramic products, what process is used. Finished ceramic products have what kind of characteristics?

3. Raw materials for ceramic mugs

Ceramic products (including ceramic coffee cups, ceramic tableware, etc.) of raw materials, production plants generally become: porcelain clay. The composition of porcelain clay is mainly clay (Al2O3-2SiO2-H2O), feldspar (K2O-Al2O3-6SiO2), quartz (SiO2) and mullite (SiO2-Al2O3). Early ceramic products, including ceramic coffee mugs, ceramic plates, etc., are made of a single clay mineral raw materials, and later, with the development of ceramic technology and improve the performance requirements of the products, people gradually added to the blanks of other mineral raw materials, that is, in addition to the use of clay as a plastic raw material, but also the appropriate addition of quartz as a barren raw material, add feldspar, and other alkali and alkaline earth metal containing minerals as a flux material. Minerals as flux raw materials. At present, there is no uniform method of classification of ceramic raw materials, generally according to the process characteristics of raw materials are divided into plasticity raw materials, barren raw materials, fusible raw materials and functional raw materials of four categories.

Our daily use of ceramics, generally wearing a smooth, smooth clothes, especially daily-use ceramics, “clothes” is more concerned, some white as jade, some colorful, very beautiful. Ceramics of this garment, called “glaze”.

4. Ceramic mug glaze

Glaze is attached to the surface of the ceramic coffee mug a continuous vitreous layer, or a mixture of vitreous and crystalline layer. Ancient people may be inspired by the beautiful texture of the surface of the shell, it is consciously using shellac as the earliest glaze. China Ceramic Mug Factory learned that as early as three thousand years ago in the Shang Dynasty in China, our ancestors have learned to use rocks and mud to make glaze to decorate ceramics. The glaze used in the production of modern ceramic mugs is divided into lime glaze and long ancient glaze. Lime glaze is used to glaze fruit (similar to porcelain stone of a natural mineral raw materials) and gray glaze (the main ingredient of calcium oxide) formulated, feldspar glaze is mainly composed of quartz, feldspar, marble, kaolin and so on. In the lime glaze and feldspar glaze in the addition of metal oxides, or infiltration of other chemical ingredients, it will become a variety of glaze colors. Glaze according to the appearance of the characteristics can be divided into transparent glaze, opalescent glaze, color glaze, light glaze, lightless glaze, crackle glaze (open flake), crystalline glaze. These kinds of glazes are widely used in the current ceramic industry, if you want to know the details of these 7 kinds of ceramic glazes, please refer to: The characteristics and functions of 7 glazes of ceramic mugs

5. Ceramic mugs flower paper

We see the beautiful patterns on the outside of the ceramic coffee mugs and the logo of the company on the bottom of the mugs, all of which are flower paper. Flower paper is made of the bottom layer of the base paper (also known as paper base), the middle layer of the sol, and the surface of the cover oil composition. The printing form of flower paper can be flat printing, screen printing and stencil transfer printing, the most commonly used of these three is screen printing. Flower paper is a particularly absorbent, the surface is coated with a water-soluble adhesive film of paper, printed flower paper soaked in water, the paper absorbs water, dissolve the surface of the water-soluble adhesive, it can make the pattern of the oil agent by the surface of the paper sliding separation, after the separation of the pattern is still a little water-soluble adhesive, it can be pasted on the ceramic products. Ceramic mugs of flower paper according to the baking temperature is divided into: low-temperature flower paper and high-temperature flower paper. Low-temperature paper baking temperature is 120-180 degrees Celsius, high-temperature paper baking temperature is about 1000 degrees Celsius. Because low-temperature flower paper has a lower firing temperature, it is not suitable for microwave ovens. Ceramic mugs or ceramic tableware with high-temperature floral paper are suitable for microwave. So how to distinguish between ceramic mugs with low-temperature floral paper and high-temperature floral paper? In the future, Xinxiang ceramic mug factory will do a special topic, talk about the difference between the two.

6. Which ceramic mugs are not suitable for microwave oven

The above information can be seen, ceramic products are more suitable for microwave use. So, are all ceramic mugs, ceramic plates are suitable for microwave oven? There are also special ceramic products that are not suitable. For example: ceramic items with gold and silver edges are not suitable for microwave use. Because gold and silver wires are made of real metal, it is not resistant to high temperature. Ceramic coffee mugs with low-temperature floral paper are not suitable for microwave. Especially if the inside of the mug is printed with low-temperature floral paper and the top of the ceramic plate is printed with low-temperature floral paper. This low-temperature floral paper of ceramic products, after microwave heating, the color of the pattern will change, affecting the beauty and health. Coated ceramic mugs because the outer wall is coated with low-temperature coating, we see daily with personalized customized photos of the mug, this kind of mug is coated mug. This coating transfers the photo to the mug at 200-400 degrees Celsius. Therefore, coated mugs are not heat resistant and are not suitable for use in the microwave. For more information about coated mugs, please refer to: Custom Coated Mugs with Coating, Foil and Printing Processes .

7. In summary

Ceramic mugs and other daily-use ceramics, including coffee mugs and tableware, are made from porcelain clay (clay) that is mechanically pressed and molded or slurry molded, covered with glaze, and fired at high temperatures. Therefore, whether it is the raw materials of ceramic mugs, glaze raw materials, or production process, ceramic mugs are not afraid of high temperatures, it will be suitable for microwave use.