【What is Hot Runner?】
Hot runner technology is an advanced technology applied to the gating system of plastic injection molds, and it is a hot development direction in the field of plastic injection molding processes.
The so-called hot runner molding refers to that the plastic delivered from the injection machine nozzle to the gate remains in a molten state at all times, and does not need to be solidified and taken out as waste during each mold opening. The melt retained in the gating system can be injected into the cavity during the next injection. 
An ideal injection molding system should produce parts with consistent density, unaffected by all runners, flash, and gate vestiges. Compared with cold runners, to achieve this with hot runners, it is necessary to maintain the molten state of the material in the hot runner without being ejected with the molded part. The hot runner process is sometimes called a hot manifold system or runnerless molding.

Basically, the hot manifold can be regarded as an extension of the barrel and injection machine nozzle. The function of the hot runner system is to deliver the material to each gate inside the mold

Principle of Hot Runner
The hot runner system consists of three main parts: hot nozzles, runner plates, and temperature control cabinets, and it is a complete gating structure form in plastic injection molding.
The working principle of the hot runner system is to install heaters inside the plastic mold and use the principles of heating and temperature control to keep the mold's runner in a molten state. It is like the injection unit of the injection molding machine directly extending to the gating point of the product cavity, enabling the product to be molded more directly and easily. Advantages of Hot Runner
Shorten injection molding cycle.
Improve production efficiency and reduce costs.
No sprue waste, enabling fully automated production and solving the problem of sprue waste recycling.
Improve product consistency and balance.
Enhance product quality.
Improve gate appearance.
Reduce injection pressure and clamping force.
Make difficult-to-process products easier to manufacture.

Performance of Hot Runner
Precisely control melt plastic temperature to eliminate material degradation. Balanced runner design ensures uniform filling of part cavities. No dead zones in the runner ensure fast color change, prevent material degradation, and minimize pressure loss.

Composition of Hot Runner
The hot runner system is composed of hot nozzles, hot runner plates, high-precision temperature controllers, etc.,and a single mold can be equipped with a single nozzle or multiple nozzles (up to148nozzles).

Selection of Hot Runner
Many conditions are factors to consider when selecting hot nozzles, such as: different plastic characteristics, product shape, size, thickness, weight, cavity arrangement and gate position. We have several types of hot nozzles and runner plates with different shapes and sizes to adapt to various products.