Dongguan mold temperature machine can improve the quality of castings. Currently, most die casting factories are using Dongguan mold temperature machine, and Dongguan mold temperature machine has become a standard peripheral equipment for die casting. How to use mold temperature machines to improve the quality of castings is the key to mold design. Using cold water to control the internal cooling of molds is currently a commonly used method in China. The advantage is that the use cost is low, the cooling efficiency is high, and the pipe diameter is required to be small. The disadvantages are: 1. Scale accumulates on the pipe wall, which is a heat insulating material that can reduce heat transfer efficiency, change cooling capacity, and is not conducive to automated production. The solution is to regularly clean the pipes and treat the water from the cooling tower. 2. The cold water temperature is low, the temperature difference between the cold water and the mold surface is large, and the internal stress is large. 3. High flow requirements, generally requiring 10-20 lpm of flow. The larger the casting, the higher the flow requirement, and also considering the requirement of sufficient water pressure for long distances. If the production department is stable and often interrupts production, the mold water cooling often needs to be turned off, and even the mold needs to be properly preheated, resulting in ineffective mold temperature control. When adjusting the machine, it is difficult to adjust the mold temperature with a water cooler.
Both the mold temperature controller and the cold water controller use the cooling pipes of the mold to adjust the mold temperature. The main difference is that the mold temperature controller can not only heat but also cool. Dongguan mold heaters are divided into two types: water heaters and hot oils. Proper use of mold heaters has the following benefits:
1. Improve mold life. Contact between molten metal and cold metal can cause severe thermal impact on the mold, which can quickly warm the mold; On the contrary, if the mold is preheated to above 150 degrees, the thermal impact strength of the mold can be greatly improved. Therefore, preheating the mold, especially for large and expensive molds, is necessary.
2. Reduce thermal shock. Higher fluid temperatures can increase the basic temperature of the mold (shortening the production cycle is also possible), while increasing flow can reduce the maximum temperature of the mold (strengthening internal cooling). Both can reduce the thermal shock temperature difference.
The mold temperature machine is very important for the production of thin parts. Thin walled parts require a high mold temperature to improve metal fluidity, and must be heated for a long time to maintain a high mold temperature. Especially for magnesium alloy thin-walled parts, their thermal capacity is small and the required heating power is also large.
4. Don't worry about pipe scale. Even water heaters are circulating water, which is not a big problem.
Reduce the use of release agents, reduce the cost of use, and also reduce the chance of mold enthusiasm.
6. Reduce pre production waste.
The use of point cooled cooling pipes can reduce the overheating of the core.
8. The surface quality of castings has been significantly improved.
9. The mold temperature is not affected by production interruptions, such as downtime/mold repair/shift change.
10. Stable production quality without relying too much on the experience of operators.
11. Reduce the temperature gradient of the mold, improve mold temperature imbalance, and reduce deformation.
12. The casting size is stable.
13. The mold temperature is stable and the number of mold repairs is reduced.
Effect of mold temperature on casting quality:
Improper mold temperatures can affect the quality of castings, and excessive temperatures can lead to:
1. The cycle time is too long
Excessive consumption of release agent
3. Reduced dimensional accuracy
4. Mold/tool deformation
5. Shrinkage/surface depression
6. Surface blistering
7. Sticking mold
8. Difficulty in ejection
9. Mold wear
Low mold temperature can lead to:
1. Cold veins
2. Filling material shortage
The following is the recommended surface temperature range for various alloy die casting molds
Zinc alloy 120-200C
Aluminum alloy 180-300C
Magnesium alloy 200-300C
Copper alloy 300-350C
Therefore, it is important to control the mold temperature within the set range. Dongguan mold warming machine is also designed for this purpose.