What is the difference between hot runner and cold runner in injection molding?

What is the difference between hot runner and cold runner in injection molding?

Hot runner: It is a heating component system used in injection molds to inject melted plastic particles into the mold cavity. Hot runner: As a commonly used component in injection mold systems, it ensures that the plastic in the runner and gate maintains a molten state through heating. Because there are heating rods and heating rings near or in the center of the flow channel, the entire flow channel from the nozzle copy outlet of the injection molding machine to the gate is in a high temperature condition, allowing the plastic in the flow channel to persist in melting. After stopping the machine, it is generally not necessary to open the flow channel to remove the condensate. When restarting, only heating the flow channel to the required temperature is required. Therefore, the hot runner process is sometimes referred to as a hot manifold system, or perhaps as runner free molding.

The hot runner skill has the following benefits compared to the conventional cold runner:

1. Save raw materials and reduce costs.

2. Shorten the molding cycle and improve machine efficiency

3. Improve the surface quality and mechanical properties of the product.

4. Point gates can be used without the need for a three plate mold.

The difference between the two is as follows:

1、 Different references

1. Hot runner: It is a new structure that heats the runners and runners of traditional or three plate molds, and does not require the removal of the runners and runners at each forming stage.

2. Cold runner: After cooling in the mold, it is taken out along with the product. Removing the pouring cold material and trimming the pouring day can obtain the final product with no obvious pouring marks.

2、 Different uses

1. Hot runner: With different plastic characteristics, the shape, size, thickness, weight, cavity arrangement, and gate orientation of the product, there are several different shapes and sizes of hot nozzles and runner plates available on the market to adapt to various products.

2. Cold runner: The mold design is simple and widely used.

3、 Different characteristics

1. Hot runner: The method of overheating ensures that the plastic in the runner and gate adheres to the melting state. Because there are heating rods and heating rings near or in the center of the flow channel, the entire flow channel from the nozzle outlet of the injection molding machine to the gate is in a high temperature condition, allowing the plastic in the flow channel to persist in melting. After shutdown, it is generally not necessary to open the flow channel to remove the condensate. When restarting, only heating the flow channel to the required temperature is required.

2. Cold runner: The cold material that occurs needs to be crushed and recycled again.

Chiko precision is providing various of hot runner accessories, cold runner accessories,including not not limited to sprue bushing,edge gate,pin-point gate,valve pin,valve pin sleeve,nozzle,locating ring,thermocouples,hot sprue,switching runner,gate and etc.