LFC Special Coating

The coating is one of the important link in lost foam casting process and it’s also one of elements for successful lost foam process.

The coating performance required for LFC is different from general casting coating. It must adopt special coating for lost foam casting rather then the general casting coating. In lost foam process,the foam pattern is coated with coating. The following performances must be well controlled for LFC coating:strength, permeability,refractory degree, heat resistance performance, quick cooling resistance & quick heat resistance, low hygroscopicity, good cleaning performance, smearing, dripping performance and suspension performance and so on.

product details

description2

coating stirring

According to the scale of 1:0.6(coating : water),weighting 15kg of clean water used for one bag coating(25kg).Put the water into lost foam blender provided by Ruiou, then add one bag coating in one time(Must use the whole bag). Start the power,after the blender running 30min, observe the stirring state,if the Baume degree is bigger than using request,add 500ml of water every time. Measure again after 15min until it satisfy the using request.

The coating’s site control

There are many coating control performances, shown mentioned above. However, in the production site, it can control coating density, coating layer weight and coating’s PH value.

1 The coating density

The coating density can be tested by density gauge(hydrometer). It can also be tested by volumetric method.

The coating density reflects the dilute and stiff state. In certain brushing methods, it really reflects coating thickness on foam plastic model, that is the coating layer thickness. It is an important performance of coating, which should be controlled.

Many casting coating is tested in flowing cup viscosity in the site. By it, you can control dilute and stiff state. However, the lost foam water-based coating is high thixotropy false fluid with bending value. Its flowing cup viscosity is different to be tested. Therefore, in the production site, it uses the coating density to control the dilute and stiff degree.

2 The coating layer weight

In the production site, it can test white model(foam plastic model)weight(G1). After brushing coating, it can test the whole weight of white model and coating(G2) after coating drying. G2-G1 is coating layer weight G. In producing some product,if you know the weight G,you can estimate the coating thickness.

3 The coating PH value

The lost foam water based coating mainly uses bentonite as inorganic binder. At the same time, it adds all kinds of organic binders.The coating PH value reflects coating stability and performance.It should be controlled.

The coating PH value can be tested by PH test paper.