Aluminum has uniform heat conduction, easy molding and beautiful appearance, and can be compounded with other metals or alloys. It is the main material of mid-range cookware. However, in the actual use process, the aluminum liner can not directly contact with food, and the surface must be protected. Thinning and stretching technology is often used in the manufacture of aluminum liner, which can keep the necessary thickness of the pot edge and bottom, and the liner looks thicker on the premise of saving materials.

2, stainless steel liner:

The best stainless steel liner is made of 304 plate, which has excellent corrosion resistance and intergranular corrosion resistance. Generally, 4L cylinder liners are made of about 0.5 plates, and 5L and 6L cylinder liners are made of about 0.8 plates. 202 plate will be used to process slightly inferior stainless steel liner, and the rust prevention ability of 202 plate is slightly worse than that of 304 plate. The stainless steel liner at the lower end is 20 1 plate. Because the 20 1 stainless steel that can be purchased in China at present is difficult to meet the National Hygienic Standard for the Dissolution of Harmful Metals from Stainless Steel Tableware Containers, the stainless steel rice cooker with extremely low price must be carefully selected.

3, composite multilayer material gasket:

The composite multi-layer material liner is made of many materials, which is divided into two layers: outer aluminum and inner steel. Its inner surface is stainless steel, which not only meets the requirement of stainless steel, but also makes use of the integral soaking effect of aluminum to improve the thermal conductivity of stainless steel. The inner wall of the liner is made of aluminum and the outer layer is made of stainless steel. The surface of inner aluminum can't directly contact with food, so it needs protection. The steel-aluminum-steel three-layer composite liner is made of stainless steel inside and outside, with an aluminum interlayer in the middle.

4, ceramic (purple sand) liner:

Purple sand belongs to pottery and is a safe inorganic material. The inner container made of purple sand is rich in natural iron, zinc, calcium and other trace elements beneficial to human health. Cooked food has good taste, super hard surface, wear resistance, acid and alkali corrosion resistance and good heat preservation performance.