Ceramic dining utensils are popular with consumers for their ease of cleaning, acid and alkali resistance, and convenience of high temperature disinfection and steaming, cooking, burning, and baking foods. Beautiful shape, beautiful decoration of high-end ceramic vessels not only has practicality, more artistic appreciation, is a daily necessities.

  Ceramic classification

  (I) Classification by porcelain species. At present, the main circulation in the market is daily fine porcelain, daily common porcelain, daily porcelain, bone porcelain, exquisite daily porcelain, glazed(medium) daily porcelain, daily fine pottery and so on.

  (II) Classified by flower surface decoration method. According to the characteristics of the flower face can be divided into glaze color, glaze color, glaze color, color glaze, white porcelain and so on.

  Glaze color refers to a product that is decorated with ceramic pigments on the glaze of a ceramic product and then baked at 700 ~ 850 °C. Because the baking temperature did not reach the melting temperature of the glaze layer, the decorative pattern did not sink into the glaze and was only attached to the glaze surface. The luster of the decorative pattern was significantly different from the luster of the glaze.

  The decoration method of the glaze color is the same as that of the glaze, but the baking temperature is higher than that of the glaze, reaching the melting temperature of the ceramic glaze. The ceramic pigment sinks into the glaze when the glaze melts, and is covered by the glaze after cooling. The gloss of the decorative pattern is the same as that of the glaze.

  The underglaze color decoration is carried out on the mud billet. After the glaze is applied, the high temperature is burned at one time. This product is the same as the glaze color. The decorative pattern is covered by the glaze layer. The luster of the decorative pattern is consistent with the luster of the glaze.

  Color glaze porcelain is to add a high temperature agent to the ceramic glaze, so that the fired product glaze presents a certain specific color, such as yellow, blue, bean blue and so on.

  White porcelain usually refers to ceramics that have not been decorated with any color.

  Different decorative methods bring different decorative effects. The decorative effects of glaze color products are bright and colorful. Glaze color products and underglaze color products are generally more elegant, and the colorful degree of color is not as good as glaze color products. Consumers can choose products with different decoration methods according to their own preferences.

  Analysis of Important Indicators

  (I) Lead dissolution, cadmium dissolution

  The index of daily ceramic products related to human health is the dissolution of heavy metal elements such as lead and cadmium. Glaze color products, underglaze products, color glaze porcelain, white porcelain lead dissolution amount, cadmium dissolution amount is very little or almost no, most glaze color products lead dissolution amount, cadmium dissolution amount is also very low, In the national standard control range. A handful of glaze colored products use inferior pigments, or excessive use of pigments containing lead and cadmium in the flower surface design, or insufficient temperature and ventilation conditions during roasting, lead dissolution and cadmium dissolution will exceed the national standard. The maximum allowable limit.

  (2) Adaptability of microwave oven, refrigerator to microwave oven, refrigerator to oven

  This indicator is a new indicator that is closely related to consumer use of daily pottery products in GB/T 3532-2009 "Daily China" and is a characteristic indicator that indicates whether the product is suitable for use in microwave ovens and ovens.

  Since daily ceramic products have a certain amount of water absorption, the billet will inhale some water during the cleaning process after use. The vaporization of water during the use of microwave ovens and ovens may cause cracking or damage of the product. Very few products may be due to the speed of water gasification, water vapor can not escape through the products glaze, causing the product to burst in the microwave oven and oven.

  (III) Water absorption and thermal shock resistance

  The water absorption rate is a characteristic indicator of the density of ceramic products after firing. The water absorption index is the basis for dividing ceramic porcelain species. The water absorption rate ≤ 0.5 %, ≤ 1.0 %, ≤ 5.0 % ceramics, respectively, are fine porcelain, porcelain, and enamel. The water absorption rate ≥ 10 % is pottery. In general, the smaller the absorption of water, the longer the service life of the product.

  Thermal shock resistance is a characteristic index that indicates that ceramic products do not have cracks or breakage when they resist rapid changes in external temperatures. It is an important performance indicator. Daily ceramic products are mostly exposed to heated foods during the use of ceramic products. Products with poor thermal shock resistance can cause cracks or breakages in the products under the action of thermal impact. The strength of the products is low and they may break when they contain food. Causing damage to the human body.

  III. Points to Note

  (I) Product appearance quality

  Consumers can first look at the product box or box documents indicated by the product name and grade; Secondly, the actual quality of the product can be observed with the naked eye. When purchasing, we should try to select products with no obvious defects on the surface and standard device type. Disk, bowl products, the size of several products can be stacked together, to observe the distance between them, the distance is not uniform, indicating that the type of the device is not regular, large deformation. For a single product, it can be placed flat or buckled on the glass plate to see if it is consistent with the glass plate to determine the size of the deformation. For porcelain products, you can hold it on your hand and tap the edge with your finger. If you make a muffler, there is a crack inside.

  (2) Preliminary judgment of lead dissolution and cadmium dissolution

  Glaze color, underglaze color products lead dissolution amount, cadmium dissolution volume is very little or almost no, you can be assured to purchase.

Glaze color products should be purchased according to the purpose of use. To reduce the impact of lead dissolution and cadmium dissolution, the following methods can be adopted:

  1, used to contain acidic food vessels, should try to choose products with less surface decoration patterns.

  2, should pay attention to the color of the pattern when shopping, if not bright, may be the temperature does not meet the requirements at the time of roasting, the amount of lead dissolution of such products and/or cadmium dissolution is often higher.

  3),Pay special attention to products that can erase patterns by hand. This product often has extremely high lead dissolution and/or cadmium dissolution.

  4, for products that are not assured, can be soaked in vinegar for several hours, if found to have obvious changes in color should be abandoned.

  (III) Use precautions

  For products that may be used in microwave ovens, ovens and dishwashers, please choose the products marked "suitable for microwave ovens, suitable for ovens, suitable for dishwashers".

For products with large usage, such as catering industry, it is advisable to select products with thicker edges with arc-shaped reinforced edges. Such products are not easily damaged in use.

  3) It is recommended not to use products that have been cracked. The strength of such products is low, they may break up when they contain food, causing damage to the human body, and due to the presence of cracks, they will hide dirt during use and are not easy to clean, which may cause bacteria to breed. It affects human health.

  For products marked for decoration, they can not be used to contain food. The dissolution of lead and cadmium of such products is not controlled by the standard limit.