Properties of Moulding Sands :

Properties of Moulding Sands :

1: porosity or permeability :

It is the property of sand which permits the steam and other gases to pass through the sand mould. The porosity of sand depends upon its grain size, grain shape, moisture and clay components are the moulding sand. If the sand is too fine, the porosity will be low.

 

2: Plasticity :

It is that property of sand due to which it flows to all portions of the moulding box or flask. The sand must have sufficient plasticity to produce a good mould.

 

3: Adhesiveness :

It is that properties of sand due to it adheres or cling to the sides of the moulding box.

 

4: Cohesiveness :

It is the property of sand due to which the sand grains stick together during ramming. It is defined as the strength of the moulding sand.

 

5: Refractoriness :

The property which enables it to resist high temperature of the molten metal without breaking down o r fusing.

6: Chemical Stability :

The property of sand to resist chemical reaction with molten metal is termed as chemical stability.