Binder

A binder is a substance that holds the abrasive grains to the backing of the abrasive tool and positions the individual abrasive grains relative to each other.

Binders include:

• Natural glues – such as bone and hide glues, which are characterized by good adhesion to the backing, easy drying, high flexibility, and low cost.

• Synthetic materials – such as resins, known for their high hardness, excellent adhesive properties, mechanical and chemical resistance to heat, and insensitivity to processing fluids.

Fillers made from powdered organic materials, like chalk, are added to binders to increase heat resistance and reduce friction.

The binder layer typically consists of two sub-layers:

• Base coat – on which the abrasive grains are spread.
• Top binder – which firmly attaches the grains to the backing.

Additionally, in selected abrasive materials, a third layer is used:

• Special (external) coating – a thin layer of special substance applied to facilitate rapid heat dissipation and reduce friction. Other special coatings are also used, such as anti-clogging layers to prevent dust buildup on the surface of abrasive tools during sanding, as well as antistatic materials to prevent the formation of electrostatic charges that complicate the machining process.