Regarding the Injection Molding Process of Industrial Special Ceramics

Ceramic injection molding: refers to the molding of a certain shaped model by injecting molten colloids into the mold cavity through pressure. The process principle is to melt solid plastic at a certain melting point, inject it into the mold at a certain speed through the pressure of the injection machine, and solidify the plastic through a water channel to obtain the same product as the designed mold cavity. Mainly used for the molding of thermoplastic plastics, it can also be used for the molding of thermosetting plastics

1. Process flow: The complete injection process includes: 1. Preparation before molding; 2. Injection process; 3. Post processing of products.

2. Preparation before molding: In order to ensure smooth injection molding and product quality, a series of preparation work such as raw material pretreatment, cleaning of machine barrels, preheating of inserts, and selection of release agents need to be carried out before production.

3. Injection process: The injection process generally includes: feeding - plasticizing - injection - cooling - demolding.

4. Injection molding feeding: As injection molding is an intermittent process, quantitative (constant volume) feeding is required to ensure stable operation, uniform plastic plasticization, and ultimately obtain high-quality plastic parts.

5. Injection molding plasticization: The process in which the molding material is heated, compacted, and mixed inside the injection machine barrel, transforming from a loose powder or granular solid state into a continuous homogenized melt.

6. Injection molding injection: The plunger or screw starts from the measuring position inside the barrel and applies high pressure through the injection cylinder and piston to pass the plasticized plastic melt through the barrel. The process of quickly feeding the nozzle at the front end and the pouring system in the mold into the closed mold cavity. Injection can be further divided into three stages: flow filling, pressure maintenance and compression, and backflow.

7. Injection molding cooling: When the plastic in the pouring system is frozen and no longer needs to be kept under pressure, the plunger or screw can be retracted to remove the pressure of the plastic melt in the barrel, and new material can be added. At the same time, cooling media such as cooling water, oil, or air can be introduced into the mold to further cool the mold. This stage is called the cooling after the gate is frozen. In fact, the cooling process starts from the injection of plastic melt into the mold cavity, which includes the period from filling, holding, to demolding.

8. Injection molding demolding: When the plastic part cools to a certain temperature, the mold can be opened, and the plastic part is pushed out of the mold under the action of the pushing mechanism.

9. Post treatment of products: ① Annealing: eliminating residual stress; ② Humidity regulation: stabilizes the color, performance, and size of plastic parts.

10. Advantages and disadvantages of injection molding

① Advantages: It can produce special ceramic materials with small size specifications and special shapes, which can be mass-produced;

② Disadvantage: Cannot produce products with large size specifications