What are the different types of runners in the mold?

In the process of plastic product processing, the mold is an indispensable key component, and the runner, as an important component of the mold, has a significant impact on the flow and filling of plastic melt, as well as the quality of the product. The quality of runner design is directly related to production efficiency, product cost, and product quality. Therefore, a deep understanding of the different types and characteristics of flow channels in molds is of great significance for improving the production efficiency and quality of plastic products.
1, Mainstream channel
The main channel is the part of the mold that is directly connected to the nozzle of the injection molding machine, responsible for introducing plastic melt from the injection molding machine into the mold cavity. The design of the main channel should take into account factors such as the flow performance of the melt, injection pressure, and temperature. The common types of mainstream channels are conical and cylindrical. The conical main channel is conducive to the smooth introduction of the melt and reduces flow resistance; The cylindrical main channel has the characteristics of simple structure and convenient processing.
2, Diversion channel
A diversion channel is the connecting part between the main flow channel and the mold cavity, which is used to distribute plastic melt from the main flow channel to various cavities. The design of the diversion channel should take into account factors such as the flow balance of the melt, flow velocity, and pressure loss. According to different shapes and layouts, diversion channels can be divided into various types such as U-shaped, V-shaped, trapezoidal, and semi-circular. These types of diversion channels each have their own advantages and disadvantages, such as U-shaped diversion channels with low flow resistance but high processing difficulty; The trapezoidal diversion channel has good flow balance.
3, Sprue
The gate is a narrow passage between the diversion channel and the mold cavity, and is the last gate for plastic melt to enter the mold cavity. The design of the gate has a significant impact on the quality, appearance, and performance of the product. There are various types of gates, including direct gates, point gates, side gates, hidden gates, and sector gates. Each type of gate has its specific application scenario and advantages and disadvantages, such as a simple direct gate structure, but the surface of the product is prone to leaving gate marks; The latent gate can effectively conceal the gate marks, but it is more difficult to process.
4, Cold material well
A cold well is a cavity located at the end of the main flow path, used to collect cold materials and impurities generated at the beginning of injection molding. The design of the cold material well helps to prevent cold materials and impurities from entering the mold cavity, which affects the quality of the product. The common types of cold well are conical and cylindrical, which can be selected according to the mold structure and product requirements.
5, Exhaust groove
The exhaust groove is a channel in the mold used to expel gas from the mold cavity. During the process of filling the mold cavity with plastic melt, a large amount of gas is generated. If not discharged in time, it can lead to defects such as porosity and shrinkage in the product. Therefore, reasonable design of exhaust slots is crucial for improving product quality. The position and number of exhaust slots need to be determined based on the shape and size of the product to ensure smooth gas discharge.
6, Temperature control system flow channel
With the continuous development of mold technology, the application of temperature control system runners in mold design is becoming increasingly widespread. This type of channel achieves temperature control of plastic melt in the channel through built-in heating or cooling elements. This helps to maintain the stable flow performance of the melt, improve the quality and consistency of the product. The design of temperature control system flow channels needs to consider factors such as the layout of heating or cooling components, power, and control methods.
There are various types of runners in molds, each with its own specific application scenarios and advantages and disadvantages. In practical applications, it is necessary to comprehensively consider factors such as product requirements, production efficiency, and mold structure, select appropriate flow channel types, and carry out reasonable design. Meanwhile, with the continuous progress of mold technology, new types and technologies of flow channels will continue to emerge, bringing more innovation and development opportunities for the plastic product processing field.