Reasons for the deformation of the blank of the lost foam casting

The lost foam casting process has the obvious characteristics of high casting dimensional accuracy and less environmental pollution. It has developed rapidly in recent years, but forging deformation is one of its common shortcomings. The following foundries will give you a comprehensive understanding of the causes and causes of lost foam casting and forging blank deformation. solution!

The yellow film deformation caused by the forming process and the solution

When the yellow film is forming the posterior tooth model, because some geometric shapes are relatively complex, it is easy to standardize the air pressure and pressure when the mold is drawn, and it will produce physical drawing deformation when the tooth model is made by hand.

Solution:

1. When making molds, use Teflon-coated abrasives as much as possible;

2. The mold draft angle is moderate;

3. Use moderate standard air pressure;

4. The shell type white mold can be fixed with adhesive tape;

White mold deformation and solution when white mold is drying

When the white mold is drying, it is unscientific to place it, and if the layer is too high, it will cause deformation. The drying time of the white mold is not suitable, resulting in insufficient shrinkage or too much shrinkage of the linear specification of the white mold, and the wool damage specifications after pouring do not meet the requirements of the engineering drawings.

Solution:

1. When drying and placing the white mold, use a drying iron shelf, which neither wastes the indoor space of the drying room nor deforms the density of the lost foam casting;

2. White mold drying has two functions, one is to dry the moisture in the internal structure of the white mold, and the other is to make the residual styrofoam in the internal structure of the white mold escape. The white mold will cause linear shrinkage when it is dried. The mold manufacturer always reserves the shrinkage capacity of the white mold when designing the plan. However, for different products, the same drying ambient temperature and drying time, the linear shrinkage of the white mold will not be the same, so different products have different drying processes. During the manufacturing process, not only the two functions of drying the white mold should be taken care of, but also the specification of the casting blank after shrinkage should be ensured.