Backings

Materials used for the backing of flexible abrasive tools include:

Paper:

• Thin paper (80-105 g/m²) – Used for hand sanding or with handheld sanders.
• Medium-thickness paper (105-160 g/m²) – Also used for hand sanding or with handheld sanders.
• Thick paper (200-300 g/m²) – Suitable for large stationary sanders.

Due to their sensitivity to high temperatures, paper-backed tools are primarily used for manual and machine sanding of wood, wood-based materials, and lacquers.

Fabrics:

• Cotton fabric backings – Compared to paper, cotton backings are more resistant to stretching, with a tear strength of around 300 N/cm. Cotton backings, available in various levels of flexibility, are used in all sanding operations, both manual and machine-based, for materials such as metals, wood, glass, rubber, and plastics.

• Synthetic fabric backings (mainly polyester) – These are three times stronger than cotton, with a tear strength of around 950 N/cm, and are much more rigid. They are used in machine processing, especially for metals, but also for glass, plastics, wood, and wood-based materials. These backings can also be used in grinding operations that involve cooling and lubricating agents.

Fiber:

Fiber backings come in various thicknesses, ranging from 0.4 mm (J-flex) to 0.85 mm (X).

Common Backing Modification Processes:

• Flexing – A process used to achieve the appropriate flexibility for a specific sanding operation by “breaking” the surface of the fabric (usually cotton) in various planes.