Electrostatic discharge materials
Electrostatic discharge materials are plastics that reduce static electricity to protect against damage to electrostatic-sensitive devices or to prevent the accidental ignition of flammable liquids or gases.
Materials
The properties relevant to a material in an ESD context are:- Conductivity: how well it passes electricity. When dealing in thin sheets, sheet resistance is used, describing the resistance of a square of the material for a current flowing from one edge to the opposite edge. The value is depends on the thickness of the material.
- Antistatic: whether rubbing can cause dangerous electrostatic buildup on the material via triboelectric effect.
- Static-dissipation: whether any existing static charge can be gradually removed by conducting through the material.
- Shielding: whether the electromagnetic field due to an electrostatic discharge from the outside results in a non-dangerous amount of voltage on the inside.
- Isolation: whether the two sides of the material are electrically isolated enough, so that any discharge that happens across the material is weak enough.
| Material | Ohms per square | Shielding | Antistatic | Dissipation | Isolation | Purpose |
| Metals | < 10−3 | Used as shielding layer in some moisture-barrier laminates. | ||||
| Metalized film | 10-1 to 102 | Used as part of shielding laminates and some moisture-barrier laminates. Always appears silvery-translucent. | ||||
| Carbons | 1 to 103 | Not used in pure form as it generates powder easily. May be incorporated into composite materials. | ||||
| Conductive plastic | 103 to 105 | Used as a film to make ESD bags. Also used to make solid plastic pieces, foam, and bubble-wrap. Always appears opaque black. Carbon-loaded elastomers such as rubber and Ethylene-vinyl acetate are also used. | ||||
| Dissipative plastic | 107 to 1011 | Used as a film to make ESD bags. Also used as a part of shielding laminates. Also used to make foam and bubble-wrap. Typically translucent pink due to added coloring. | ||||
| Insulators and base polymers | > 1013 | Not an ESD material: charges will build up. |