Winter in precision casting plants

Winter in precision casting plants

For most investment casting factories, it will become very difficult to control the temperature and humidity between shell making in winter due to the decrease in temperature and the drying of the air. Today, precision casting manufacturer Tianyao Metal will talk to you about the winter of precision casting factories.

We have mentioned many important things about shell making earlier, such as: more than 50% of investment casting defects come from the shell making process; The shell making process is by no means a simple matter of playing with mud, simply pouring refractory powder and silica sol together can make a good shell. There is a lot of content and technology inside. The first three processes of investment casting, including wax modeling, shell making, and smelting and pouring, are all important and not a single one is simple.

So, winter is here, as an investment casting manufacturer, which ones do you need to consider?

1、 The problem is the storage of silica sol. Because the storage of silica sol is temperature limited, ranging from 0 to 40 ℃. In many cases, the room temperature may be below zero, so it is necessary to place the silica sol in a suitable temperature place, and it must also be sealed and stored. Otherwise, there is a risk of failure and aging of the silica sol.

2、 Temperature and humidity control in the shell making room, especially in the humidity control between the surface layers. Since entering winter, the air has become very dry, and the humidity will correspondingly decrease. So, the humidity between the surface layers may decrease. Of course, for most products, the impact of humidity changes may not be very significant, but it is still necessary to make corresponding adjustments to the drying time of the surface layer products based on seasonal conditions. For example, what used to take 4 hours to dry may now be reduced to 2.5-3 hours, and it is also necessary to avoid severe drying. Generally speaking, in winter, the spacing between layers of shell making, especially between the surface layer and the transition layer, should be accelerated. In addition, for complex products, it is necessary to ensure humidity. Small areas can be established locally to create a suitable humidity atmosphere. For example, wrapping the hanging car with plastic cloth can increase the local humidity appropriately, and the drying speed can be stable to improve the adverse effects caused by winter drying. For large surface dry spaces, it is necessary to monitor humidity at multiple locations, and watering is also an effective way to ensure humidity.

Generally speaking, winter is also a good thing for melting, because the decrease in ambient temperature is very conducive to the solidification of castings, and some slight shrinkage and looseness may also disappear during normal times. But things always have both positive and negative aspects, where there are advantages and disadvantages. Cooling is not a problem, but the decrease in shell temperature is also not a problem, so there are more undercastings in winter. Wearing cotton clothes on the shell, increasing the shell roasting temperature, increasing the shell thickness, and burying the box for pouring, etc. The solution is something people come up with, there are always more solutions than difficulties!

Precision machining