Basic Requirements for Enamel Products Firing
Firing is an important stage in the production of enamel products. If the correct firing time and firing temperature are not mastered, it may cause the enamel products to be burnt or excessive. In addition to the firing time and temperature, the support point of the firing rack and the position, arrangement method and cooling of the powder in the firing kiln will affect the quality of the enamel products. So, how to correctly master the firing process of enamel products?
1. Firing temperature
Firing temperature refers to the temperature at which the temperature gradually increases and the performance reaches the optimum value when the powder is fired. It is an important condition to ensure the internal and external quality of the product, and it must be carried out in strict accordance with the process regulations. The firing temperature depends on the type and nature of the enamel frit, so it is best for enamel factories to adopt a mature solution when purchasing enamel frits.
2. Firing time
At the firing temperature, the time required for the product to go from entering the kiln to exiting the kiln is called the firing time. It depends on factors such as the size and thickness of the iron billet, the properties of the enamel and the thickness of the enamel.
3. Other requirements
Burning rack support point: refers to the contact point between the powder blank and the burning rack tooth tip during firing. Because the enamel will be sticked off and leave the frame eye, which affects the appearance and use, so the supporting points should be few and small, and their positions are generally selected in the non-main parts of the product, such as the lower edge, edge or outer bottom, etc. If the support If the point is not selected properly, the enamel product may be burned and deformed.
The support point should be selected as close to the arc of the iron billet as possible, and the ground coat and cover coat frit can also be selected in different parts to spread the frame eyes and reduce deformation. For example, for a disc with a diameter of 50cm, the support point of the ground coat is far from the inner bottom, and the support point of the cover coat is selected at the outer bottom.
The position and arrangement of enamel products in the firing kiln: 1. The enamel products need to keep an appropriate distance from the kiln wall, generally greater than 8cm, and the bag-shaped kiln should not be fired near the door of the furnace; 2. The products need to maintain an appropriate distance, large Pieces are greater than or equal to 7cm, and small pieces shall not be less than 5cm; 3. The distance between the product and the bottom of the kiln is greater than or equal to 10cm.