There are a wide variety of powder coating technologies used in many different industries. Coaters that are dealing with products that come in contact with electricity such as electrical cabinets, electrical housings, wire harnesses and computers require very specific powders. It is imperative to know how these powders will react to electrical charges. Materials are generally classified as insulators, static dissipative or conductive. These properties are a measure of resistance and resistance is the inverse of conductivity. The unit of measure is called ohms (Ω). The classifications are as follows:
- Insulating materials exhibit resistance greater than 1 X 109 ohms. Insulators have tightly bound electrons whose internal electric charges do not flow freely; very little electric current will flow through it under the influence of an electric field. Most powder coatings are in this range, with epoxy being higher than polyester. These type of applications can be found used to insulate wires, pipes and hoses.
- Static dissipative materials exhibit resistance between 1 X 106 and 1 X 109 ohms. For these materials, the charge flows through the material slowly and in a somewhat more controlled manner than with conductive materials. Dissipative materials are classified “Antistatic” and are considered to be the ideal range for ESD materials. These materials are widely used in and around all computer components to eliminate shock.
- Conductive materials exhibit resistance less than 1 X 106 ohms. Conductors have low electrical resistance, electrons flow easily across the surface or through the bulk of these materials. Charges go to ground or to another conductive object that the material contacts or comes close to. Metals have resistance of 0 to 0.1 ohms. Zinc rich will be less than 1 X 106 ohms. Conductive features are typically not sought after in the coatings that deal directly with electricity. One should always consult the engineer of the project as well as a powder coating specialist to make sure all requirements are being achieved.
Going from a black color to a white color will change the resistance, also additives will influence based on their conductive nature, so If I add zinc to the same formulation, the resistance will drop as I increase the zinc level. If you are a manufacture or a coater of components such as electrical cabinets, robotics, computer housings and /or a surface that requires specific resistance to electricity, contact TIGER and let us help. We have stock options of powders that have been tested to the fullest measures.
National Sales Manager