The Functions of Starch Ether in Mortar

Starch ether used in gypsum – based products

The demand of gypsum plaster in dry mixed mortar products is huge, whether plastering by hand or machine, while starch ether plays a very important role. Starch ether can provide thickening effect for the mortar so that the mortar can obtain good consistency during application. Starch ether is a very effective thickener for plaster. Adding low dosage of starch ether-usually within the range of 0.03%- 0.1%, can achieve a very good thickening effect, so that the mortar can be available immediately. Co- using with retarder will extend the working time.

In traditional mortar, the consistency increases rapidly when gypsum powder is mixed with water, resulting in the expected and applicable consistency of the mortar for very short time. Hence the working time is too short.

The addition of the retarder extends the working time of the mortar, but it has to wait for required interval till consistency is reached to be applied. It is suitable for application with shorter operation time.

When starch ether and retarder are added to mortar together, the desired consistency is immediately achieved and the gypsum plaster can be used immediately. The operation time can be adjusted by the amount of retarder added.

The amount and type of starch ether determines the consistence/thickness of plaster. By special chemical treatment of starch ether, higher thickening effect can be obtained with lower dosage in both neutral and alkali systems.