Natural sand generally not well suited for casting purposes. On continued use of molding sand, the clay coating the sand particles causing gets thinned out to reduce its strength.
Thus conditioning right sand binder accomplish uniform distribution around the grains of sand, moisture content control, eliminate foreign particles and aerates the sand.
Therefore, sand conditioning is needed for better results be achieved.
- The foreign materials, such as nails, hard sand and metal lumps from the sand used to enjoy. For removing the metal pieces, particularly ferrous pieces, the sand from the station shake out subject magnetic separator, which separates out the pieces of iron, nails etc. from the sand used.
- Next, the sand is examined in a separate measuring out the hard sand lumps etc. The measurements can be manual as well as mechanical. Mechanical measurements may be operated compressed air or electricity works. But electricity measurements are faster and can handle large quantities of sand in a short time. – After all these foreign particles to remove and the sand free from hard lumps etc., proper amount of sand pure, clay and additives have added to for the loss due to the burned, clay and other materials. As the moisture content of the sand back on knowledge, it is tested and after knowing the moisture on the required amount of water added.
- There are two ways to add water to clay and sand. In the first method, the first water is added followed by clay sand, and other means, is clay followed by addition of water. It has been said that the best order of ingredients adding sand to clay bonded sand with water followed by the binders. In this way, the clay is faster and uniformly spread the sand grains. A further advantage of the mix order is less dust produced during the mulling operation. – Now, what mix well in muller mix. The main objectives of a mix muller to distribute the binders, additives and moisture or water content uniformly across every grain of sand and helps develop the best physical properties can by kneading the sand grains. Mulling makes inadequate weak sand mixture can be compensated only by more binder.
- The final step in the cooling sand conditioning mixture of sand about the fact that if the hot molding sand mixture, it will cause difficulties in molding.