Appearance Quality Standard:
Appearance quality is an important indicator of product rating. The current product standards in my country divide products into three categories: high-quality products, first-class products and qualified products. First-class products correspond to the international advanced level, first-class products correspond to the domestic advanced level, and qualified products correspond to the domestic general level. The appearance quality of high-end products mainly meets the requirements of “five digits and one small”, that is, no stains, no slag, no paint and dirt, no holes, no enamel scratches and small deformation. The spots (black spots) are commonly known as fly droppings. If there are stains on the product, people will always feel dirty, which will affect their appetite. First-class products and qualified products have less stringent requirements than superior products in terms of allowable defects.
Solubility standard for lead and cadmium:
The dissolution of lead and cadmium is an important indicator of the safety and health of ceramic products. The presence of lead and cadmium is caused by their components contained in ceramic pigments in decorative images located on the surface of the product. The presence of lead may also occur due to the addition of lead-containing components to reduce the fire temperature of the surface glass layer of the product. If the manufacturing process is not properly controlled, excessive dissolution of lead and cadmium can occur very easily during use. Frequent use of these products can easily lead to heavy metal poisoning with lead and cadmium.
National standard GB12651-2003 “Permissible limits for the dissolution of lead and cadmium in ceramic products in contact with food” is a mandatory national standard, which covers all ceramic kitchenware in daily use. The standard specifies that lead and cadmium dissolved in one product must not exceed the specified allowable amount, including flat products (products where the depth from the lowest internal level of the product to the end height is less than 25 mm).
Reported values are: lead dissolution rate 7 mg/L, cadmium dissolution rate 0.50 mg/L; Small hollow products (products whose depth from the inner plane of the product to the height of the mouth edge is greater than or equal to 25 mm and the volume is less than 1.1 L) are represented as follows: the amount of lead dissolution is 5.0 mg/L, the amount dissolved cadmium is 0.50 mg/liter; Large hollow products (products whose depth from the inner plane of the product to the height of the mouth edge is greater than or equal to 25 mm and the volume is greater than or equal to 1.1 L) are shown as follows: lead dissolving dose 2.5 mg/L and a cadmium dissolution rate of 0.25 mg/L.
Criteria for thermal stability:
Thermal stability means that the product does not crack or break when changing between cold and heat. The quality of thermal stability can reflect the service life of ceramic products. The greater the temperature difference between the cold and the heat exchanger, the longer it lasts. The standard generally states that it is heated to 180°C and then placed in hot water at 20°C. Take it out and check for any damage. There will be no damage at this temperature and the service life can be more than 2~3 years.
Post time: Aug-01-2022