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Injection mold processing is to first add plastic into the mold, and then the mold is continuously rotated along two vertical axes and heated. Under the action of gravity and heat energy, the plastic in the mold is gradually and evenly coated, melted and adhered to the entire surface of the mold cavity, formed into the required shape, and cooled and shaped. The injection process generally includes: feeding-plasticization-injection-cooling-demolding. So what preparations should be made before injection mold processing? Let me share with you today.

1. Preparation before injection mold processing
In order to make injection molding go smoothly and ensure the quality of products, a series of preparations such as raw material pretreatment, cleaning, barrel, preheating inserts and selecting release agents are required before production. The injection process generally includes: feeding-plasticization-injection-cooling-demolding.
Feeding: Since injection molding is an intermittent process, quantitative (constant volume) feeding is required to ensure stable operation, uniform plasticization of plastics, and finally obtain high-quality plastic parts.
Plasticization: The process in which the molding material is heated, compacted and mixed in the barrel of the injection machine, and is transformed from a loose powder or granular solid into a continuous homogenized melt.
Injection: The plunger or screw starts from the metering position in the barrel, applies high pressure through the injection cylinder and piston, and quickly sends the plasticized plastic melt through the barrel, the front nozzle and the gating system in the mold into the closed mold cavity. Injection can be further divided into three stages: flow filling, pressure holding and shrinkage compensation, and backflow.
Cooling: When the plastic in the gating system is frozen, it is no longer necessary to continue to hold the pressure, so the plunger or screw can be returned to remove the pressure of the plastic melt in the barrel, and new material can be added. At the same time, cooling water, oil or air and other cooling media are introduced into the mold to further cool the mold. This stage is called cooling after the gate freezes. In fact, the cooling process starts from the injection of the plastic melt into the cavity, which includes the period from filling, holding pressure to demolding.
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 by the ejection mechanism.
Injection molding: refers to a model with a certain shape, which is formed by injecting the molten colloid into the mold cavity through pressure. The process principle is: melt the solid plastic according to a certain melting point, inject it into the mold at a certain speed through the pressure of the injection machine, and the mold is cooled by the water channel to solidify the plastic to obtain a product with the same design cavity. It is mainly used for the molding of thermoplastics and can also be used for the molding of thermosetting plastics.

2. Compared with traditional blow molding and injection molding processes, the rotational molding process has the following advantages

1. Cost advantage: In the rotational molding process, only the strength of the frame is required to support the weight of the material, mold and the frame itself to prevent the closing force of the material leakage; and the material is almost not affected by any external force except the natural gravity during the entire molding process, so it has the advantages of convenient machine mold processing and manufacturing, short cycle and low cost.

2. Quality advantage. The products of the rotational molding process have more stable product quality and structure due to the lack of internal stress during the entire production process.
3. Flexibility and versatility. The machine mold of the rotational molding process is easy to manufacture and inexpensive, so it is particularly suitable for multi-variety and small-batch production in new product development.
4. Personalized design advantage. The products in the rotational molding process are very easy to change color and can be hollow (seamless and weldless). The surface treatment of the product can achieve the effects of pattern, wood, stone and metal, meeting the personalized needs of modern consumers for goods.

The products produced by this process include: fuel tanks, water tanks, mechanical housings, fenders, etc. The main substitutes are metal parts and fiberglass products.

Injection molding is a process developed based on micro-manufacturing technology such as LIGA, of course there are many other methods. The LIGA process is to first produce a model required for injection molding, which is commonly known as a "mold", and then pour liquid plastic into the mold, and finally separate it to form the final product required. For example, plastic toys, plastic housings of home appliances, injection molded parts of medical equipment, plastic packaging materials for cosmetics, plastic products for pet supplies, etc.