What is the most commonly used type of injection mold?

1, Two plate mold (single parting surface injection mold)
Two plate mold, also known as single parting surface injection mold, is the simplest and most basic form of injection mold. Its structure is relatively simple, consisting of two parts: a moving mold and a fixed mold. The moving mold and the fixed mold are separated by a parting surface to form a mold cavity. During the injection molding process, the plastic melt is injected into the mold cavity through the nozzle of the injection molding machine, and after cooling and solidification, the moving mold and the fixed mold are separated to remove the injection molded part.
Structural features: The design of the two plate mold is flexible and can be designed as a single cavity mold or a multi cavity mold according to product requirements, meeting different production needs. Meanwhile, its mold structure is simple, the manufacturing cost is relatively low, and it is easy to maintain and upkeep.
Working principle: During injection molding, the moving mold and the fixed mold are closed, forming a closed mold cavity. Plastic melt is injected into the mold cavity through a nozzle under the action of an injection molding machine. After the injection molding is completed, the moving mold and the fixed mold are separated, and the injection molded parts are left on one side of the moving mold or fixed mold together with the flow channel system. The injection molded parts are removed from the mold through the ejection mechanism.
Applicable scenarios: Two board molds are widely used in the production of plastic products with simple structures and low dimensional accuracy requirements, such as daily necessities, toys, packaging materials, etc.
Advantages and disadvantages: The advantages of the two-board mold are its simple structure, low manufacturing cost, and ease of operation and maintenance. However, its disadvantages are also quite obvious, such as the easy wear of the mold parting surface, scratches during the removal of injection molded parts, and waste of raw materials in the flow channel system.
2, Three board mold (double parting surface injection mold)
Three board mold, also known as double parting surface injection mold, has a relatively complex structure consisting of three parts: moving mold, intermediate plate, and fixed mold. Compared with the two plate mold, the three plate mold adds a partially movable intermediate plate (also known as a movable sprue plate) in the fixed mold part, which is used to separate the runner system and injection molded parts.
Structural features: The structural design of the three plate mold is more complex, but it can achieve the separation of the flow channel system and injection molded parts, reducing raw material waste. At the same time, its mold structure is more flexible and can be designed with various feeding methods such as point gates and side gates according to product requirements.
Working principle: During injection molding, the moving mold, intermediate plate, and fixed mold are closed to form a closed mold cavity. The plastic melt is injected into the mold cavity through a nozzle, and after cooling and solidification, the moving mold separates from the intermediate plate, and the intermediate plate separates from the fixed mold again, thereby achieving the separation of the flow channel system and the injection molded parts. The injection molded parts are removed from the mold through an ejection mechanism, while the flow channel system remains on the middle plate or fixed mold side.
Applicable scenarios: Three board molds are suitable for producing plastic products with complex structures and high dimensional accuracy requirements, such as automotive parts, electronic product casings, etc. At the same time, it is also suitable for situations that require reducing raw material waste and improving production efficiency.
Advantages and disadvantages: The advantage of the three plate mold is that it can separate the flow channel system from the injection molded parts, reduce raw material waste, and improve production efficiency. However, its structure is complex, the manufacturing cost is high, and it requires high precision in mold processing and assembly.
3, Hot runner mold
Hot runner mold is a special type of injection mold, characterized by a heating system inside the mold to keep the plastic melt in a molten state until injection molding is completed. Hot runner molds can avoid the waste of raw materials caused by solidification of the channel system in traditional cold runner molds, and improve the utilization rate of raw materials.
Structural characteristics: The structure of the hot runner mold is complex, including components such as heating system, nozzle, and flow channel system. Heating systems usually use heating elements such as electric heating wires and electric heating rods to heat the inside of the mold, keeping the plastic melt in a molten state. The design of the nozzle and flow channel system is customized according to product requirements to meet different production needs.
Working principle: During injection molding, the plastic melt is injected into the mold cavity through the nozzle under the action of the injection molding machine. Due to the heating system inside the mold, the plastic melt remains in a molten state inside the mold until injection molding is completed. After injection molding is completed, the mold is opened and the injection molded parts are removed from the mold through the ejection mechanism. At the same time, the heating system continues to heat the inside of the mold, maintaining the molten state of the plastic melt for the next injection molding.
Applicable scenarios: Hot runner molds are suitable for producing small batches, high-precision, high-value plastic products, such as medical devices, electronic products, etc. At the same time, it is also suitable for situations that require reducing raw material waste and improving production efficiency.
Advantages and disadvantages: The advantage of hot runner molds is that they can improve raw material utilization and reduce raw material waste. At the same time, it can also improve production efficiency and reduce production costs. However, its structure is complex, the manufacturing cost is high, and it requires high precision in mold processing and assembly. In addition, the maintenance cost of hot runner molds is relatively high, requiring regular inspection and replacement of heating elements and other components.