Four Shell Making Processes for Precision Casting

Water glass shell

This process has a production history of nearly 50 years in China. After half a century of unremitting efforts of colleagues in the precision casting industry, the application and research of the water glass shell process has reached a very high level. Over the years, due to the improvement of the back layer shell refractories and the popularization and application of new hardeners, the strength of the water glass shell has increased exponentially. Low cost, shortest production cycle, excellent shelling performance and high air permeability are still the advantages that any other shell process can't do.

Water glass shell

This process has a production history of nearly 50 years in China. After half a century of unremitting efforts of colleagues in the precision casting industry, the application and research of the water glass shell process has reached a very high level. Over the years, due to the improvement of the back layer shell refractories and the popularization and application of new hardeners, the strength of the water glass shell has doubled. Low cost, shortest production cycle, excellent shelling performance and high air permeability are still the advantages that any other shell process can't.

Composite shell

Compared with the water glass shell, the surface quality of the casting has been greatly improved, the surface roughness is reduced, the surface defects are reduced, and the repair rate is reduced. It can be used for high alloy steel such as stainless steel and heat-resistant steel. The production cycle is much shorter than the low-temperature wax-silica type shell, which is close to the water glass type shell.

Silica sol (low temperature wax) type shell

This process conforms to the national conditions, and has greater adaptability and superiority when casting more than 1kg, especially 5kg or more large and medium castings. It is more stable in quality than the composite shell, especially the dimensional accuracy of the casting, because it has no water glass, the shell has high temperature performance, and the shell has high permeability and high creep resistance after firing at 1000-2000 degrees, which can be applied Thin-walled parts and small and medium-sized parts with complex structure can also produce extra large parts weighing 50-100kg, such as water pumps, impellers, diversion casings, pump bodies, ball valve bodies, valve plates, etc. For thin-walled small and medium-sized pieces or large pieces, fork shell or shell lifting can be directly poured in front of the furnace, and a high yield can be obtained.

Silica (medium temperature wax) shell

This is an internationally-precise production process for precision castings. It has the highest casting quality and the lowest repair rate. It is especially suitable for small and medium-sized pieces and extra-small pieces (2-1000g) with high surface roughness and high dimensional accuracy. However, due to equipment and cost constraints, it is rarely used in medium and large parts (5-100kg)