Static electrical charge is generated between materials through friction, pressure or separation of two materials. This is sometimes called the Triboelectric Effect. A material that inhibits the generation of static charges (generally less than 200 volts) from triboelectric generation is classified as anti-static. Anti-static materials used to make brushes include Wood, Hog Bristle, Horse Hair and Goat Hair.

These materials can be used in ESD sensitive areas as long as the brush remains in a liquid environment. In a dry environment only conductive or dissipative materials should be used in ESD safe areas. The most critical aspects of the ESD brush are the fiber, core or handle material, and grounding. Surface resistivity of the brush material largely determines the electrostatic properties of the brush.

Range of surface resistivity (ohms) is:

• 10¹² to 10¹⁶ Insulative materials
• 10⁵ to 10¹¹ Dissipative materials
• 10² to 10⁴ Conductive materials

Anti-Static brushes are made from low charging and natural materials that are near neutral on the triboelectric chart. They neither give nor take electrons and, therefore, remain essentially electrically neutral. There can, however, be a slight charge created. In extreme voltage sensitive applications, these brushes should be used only in a liquid environment.

Mounting
If the mounting location is not grounded, a grounding strap or wire incorporating a 1 megohm resistor should be used between the brush and an electrical ground. Potentially severe bodily harm may result from the use of a conductive brush if a 1 megohm resistor is not used.
Note: Conductive fibers are NOT recommended for use with unencapsulated electronic microcircuits. Minute pieces of conductive material have been known to cause short circuits.

Dissipative Brushes
These dissipative brushes have a surface resistivity of 10⁵ to 10¹¹ ohms, a higher resistivity than the conductive brushes but sufficiently conductive to preclude any static buildup in the brush. These are excellent tools to use in removing any static charge that will result in the adhesion of particles such as dust to an object. Please use these brushes with a wrist strap or other mechanism to provide a path to ground for safety.

Thunderon™ is a very fine (0.04mm, 0.0015"diameter) acrylic fiber chemically bonded with copper sulfide. This special fiber will dissipate a charge on an electrically charged surface. The surface resistivity of Thunderon™ is 10² ohms. The plastic handle is dissipative with a surface resistivity of 10⁵ Ohms