Manufacturers today use the hot runner system technique to fill the cavities in the mold parts. The temperatures of the runner and gate are controlled so that the material is heated to its flow temperature while the mold keeps cooling down. The hot runner system enables molding high-quality plastic products with shorter cycle times and lower production costs.
Figure 1: Hot runner system
It is widely used in the plastics industry and is growing in popularity in other industries as well. This technique has many advantages over traditional injection molding techniques. In this blog, we will discuss the importance and usage of hot drop injection molding.
Hot Runner System – Introduction
It is an important injection molding method that enables the production of high-quality plastic products with shorter cycle times and lower production costs. This system allows the assembly of heated components to inject molten plastic into molds. These systems are classified according to their method of heating, that is internal or external.
This system is often used in injection molding, over-molding, and plastic extrusion applications. The main advantages are:
- Reduced cycle times
- Reduced molding costs
- Increased production efficiencies
- Increased product quality
Difference between hot and cold runner system
Figure 2: Hot runner vs. cold runner system
Knowing the difference between the hot and cold runner systems is crucial because many users become confused.
- The main difference between hot and cold runner injection molding systems is that the runner is heated in a hot runner system, whereas in a cold runner system, it is not.
- Secondly, the gate in a hot runner system is also heated so that the plastic can flow easily into the mold cavity, whereas in a cold runner system, the gate is not heated.
- Thirdly, it is more expensive than a cold runner system.
- Finally, it produces less waste because the plastic does not solidify in the runner, whereas the cold runner system produces more waste because the plastic solidifies in the runner.
Hot runner injection molding process
Every injection molding industrialist must know the hot drop injection molding process to avoid defects in the mold parts. If the process is carried out correctly, it can result in the production of high-quality molded parts. The hot runner injection molding process is as follows:
- First, the material is placed into the hopper of the injection molding machine.
- Then, the material is heated to its flow temperature in the machine barrel.
- After that, the material is injected into the mold cavity at high pressure. The hot runner system lets the material flow into every corner of the cavities.
- Finally, the mold is opened, and the molded parts are ejected.
It is very beneficial in mass production because it reduces the cycle time and production cost. Moreover, it increases the productivity and quality of the product.
Hot runner system types
With time, manufacturers have discovered many types of hot runner systems. The most common types of hot runner systems are as follows:
Manifold-type hot runner system
It is the most commonly used system. In this system, the molten plastic is injected into the mold cavity through the manifold. The hot runner manifold is connected to the nozzles placed in the mold cavity. This system’s advantage is that it is very simple to use and maintain.
Shuttle-type hot runner system
It is mostly used for large molded parts. In this system, the molten plastic is injected into the mold cavity through the shuttle, which is connected to the nozzles placed in the mold cavity. This system has the advantage of being able to handle large molded parts.
Valve gate hot runner system
This type of hot runner system is mainly used for small molded parts. In this system, the molten plastic is injected into the mold cavity through the valve gate, which is connected to the nozzles placed in the mold cavity. This system’s advantage is that it can be used for small molded parts.
Price of the hot runner system
The price depends on many factors, such as the type of system, the number of nozzles, and the size of the system. However, in general, the price of a hot runner system ranges between thousands.
If you want a hot runner system for your business, please get in touch with us, and we will give you the best price.
Business compatibility with hot runner injection molding
Now the question arises if your business is compatible with hot runner injection molding, which means whether your business gains profit by using this procedure. So, the following are the circumstances where hot runner injection molding is advantageous:
- If you manufacture products that require many colors
- If you want to save money on the mold
- If you want to reduce the cycle time
- If your molded parts are large
- If you want to produce high-quality molded parts
- If you want to increase the productivity of your business
- If you want to reduce the production cost
These are the circumstances under which hot runner injection molding is advantageous. You should use this procedure if your business meets any of these conditions.
Molding services at Go4Mould
Go4Mould is well known for its molding services in almost 40 countries. We use high-quality raw materials to make our mold parts. Our injection molding gallery is filled with numerous molds successfully running worldwide, including pipe fitting molds, crate moulds, basket moulds, and many others. Our clients are satisfied and leave good feedback, hence increasing our monthly selling score.
FAQs
Why do we use the hot runner system?
We use this system because it is cost-effective and enhances project productivity. It can be used for making small, large, and mass-produced parts.
