Zinc alloy die-casting process has been proved to be one of the reliable processing methods for mass production. At present, there are always runner and overflow parts in the processing of zinc alloy die castings. Although these parts can be recycled, they are still a great waste.
In zinc alloy die casting, if we can find a solution to the hot runner process, we can save the remelting of the runner and overflow part, and save a lot of energy consumption.
This new zinc alloy die-casting technology was introduced by Fulai Company at the International Foundry Industry Expo. FGS technology (Free Gating System - Fulai gating System) has been proved by a series of on-site demonstrations that the system can save about 45% - 80% of the material to participate in recycling.

1、 FGS system composition
The core problem of FGS die-casting process is how to reduce the original gating system. The molten metal is introduced into the mold cavity near the part, where it is adjusted to the level of molten metal. Many advantages of traditional gate are maintained for filling zinc alloy die castings. That is to maintain the flow state, and do the corresponding program to simulate the filling as before.
The system is composed of heating runner components embedded in the die-casting mold. In this flow channel, the molten material is always in a liquid state. It includes complete heating and sensor technology, and temperature control is ensured by the machine. There is no mechanical seal in the system because it is not reliable in the practice of die casting process.
Such components are installed into the die-casting mould, and the corresponding die-casting mould structure is required. When designing die casting dies, heat balance should be carefully considered. In addition, the die-casting process should be matched with FGS, and the die-casting machine should ensure that the casting system and FGS system are always filled with molten metal during the whole die-casting cycle with appropriate process. In the hot chamber die casting machine, the channel of molten metal, from the furnace to the mold and FGS system, becomes an integral part in the machine and process control.
The casting process is the process of adding heat energy to the die-casting mold through the molten liquid. Therefore, this energy is brought into the system, and no other heat sources enter here. That is to say, there is no other energy in the cavitation erosion and molten liquid guide channel.
The FGS - process guidance of die casting machine can optimize the die casting process and matching through die casting itself under the influence of energy introduction into the die casting mold and casting system.
2、 FGS --- technical advantages
The use of this system has many advantages. In fact, although a heated FGS system is applied in the die casting mold, the energy balance is positively affected, because the reduction of circulating materials plays a good role.
The quality of zinc alloy die castings is significantly improved due to less air left in the system. This is also related to vacuum pumping to a certain extent.
The porosity of zinc alloy die castings has been greatly improved under better filling conditions under the alternate action of temperature regulating melt and corresponding reduction of flow filling speed.
Due to the moderate reduction of energy (pressure and speed) and the decrease of the amount of molten metal used in the pouring process, the process efficiency is greatly improved compared with the original zinc alloy die casting processing. One of the characteristics of this process is that compared with the ordinary die casting process, the material to be recycled is greatly reduced due to the multiple gaps caused by the composite runner.
FGS process is very effective, because the condensation of zinc alloy die castings is completely determined by the cycle at this time, rather than a gate of corresponding size. In addition, at present, the required first stage of zinc alloy die casting process is shortened, that is, the so-called pre-filling stage of molten metal from the pouring chamber to the gate is shortened.
When FGS technology is used for die casting, heat source is a focus of the process. Therefore, it is meaningless to reform the existing die casting mold. From the beginning, the die casting mold should be considered so that all advantages can be utilized.