At this stage, the four shell making processes widely used in the precision casting manufacturing industry in the market are water glass shells, composite shells, silica sol shells, and silica sol shells. Each has its own merits. Next, the editor will also introduce the difference between the four shell-making processes of Dongguan precision casting.

The first water glass shell
This process has been manufactured in China for nearly 50 years. After half a century of hard work by colleagues in the precision casting industry, the application and scientific research of the water glass shell technology has exceeded the very high quality. Over the years, due to the improvement of the refractory insulation materials of the back layer shell and the application and promotion of the new cinnamyl alcohol, the compressive strength of the water glass shell has doubled. Inexpensive cost, minimum manufacturing cycle time, high-quality molting characteristics and high air permeability are still the inferior advantages of all other molding processes.
Second compound shell
Compared with the water glass shell, its casting process performance has been greatly improved, the roughness is reduced, the surface defects are reduced, and the failure rate is reduced. It can be applied to high-alloy steel such as stainless steel plate and heat-resistant steel. The manufacturing cycle time is much shorter than that of the ultra-low temperature wax-silica sol shell, which is similar to the water glass shell.
The third type of silica sol (ultra-low temperature wax) shell
This process is in line with national conditions, and has greater adaptability and advantages when forging about 1kg, very large and medium-sized object castings of about 5kg. Compared with composite shells, the quality is stable, especially for castings with high-precision specifications. Because there is no water glass, the shell has good high-temperature characteristics. After firing at 1000-1200℃, the shell has high air permeability and strong stress relaxation resistance. , It can be used for thin-walled parts and large and medium-sized parts with complicated structures, as well as large objects weighing about 50-100kg, such as centrifugal pumps, centrifugal impellers, drainage casings, pump casings, gate valve bodies, valve bodies, etc. For thick, medium or large objects, fork shells or lifting shells can be used for immediate pouring in front of the furnace, and high output rates can be obtained.
The fourth type of silica sol (medium temperature wax) shell
It is an internationally versatile precision casting manufacturing process. It has the largest casting quality and the least failure rate. It is very suitable for medium and large parts with high roughness requirements and high precision specifications (2-1000g). However, due to the limitation of equipment and cost, it is less used for medium and large objects (5-100kg).
The four shell-making processes of Dongguan precision casting have their own different targets, which are based on the quality regulations, prices and delivery cycles of the castings. With full consideration, appropriate use of the most economically developed and effective shell-making process plan is the basis to ensure the production of high-quality, low-cost castings.