With excellent electrical properties ranging from fully insulating to electrically conductive, plastics are an essential material in the electrical and electronics industries.
Unmodified plastics have inherent electrical insulating properties. These electrically insulating plastics have a high resistance or are completely resistant to the flow of electrical current. They are typically used in a variety of applications in order to prevent electrical conductivity which could potentially cause damage to persons or property. Electrical insulating plastics are widely used in applications such as switches, light fittings, electric wiring and circuit boards.
The so-called volume resistance of plastics is greater than 1012 Ohm. Thus, unmodified plastics are considered non-conductors. These tend to become electrostatically charged. When materials rub against each other, they absorb electrons from each other to varying degrees. The friction causes the surfaces to acquire different electrical charges. While conductive materials quickly equalise their charges with the ground, charges accumulate on the surface of non-conductors. This can cause problems during discharge.
The CTI (Comparative Tracking Index) is often used to determine the insulating ability of a plastic. This provides a statement on the electrical insulation resistance of the surface of insulating plastics. The tracking resistance thereby characterises the insulation resistance of the surface (creepage distance) of insulating materials.
Creepage currents can occur particularly due to the effect of moisture and impurities (also temporary) on the surface. Even with well-insulating plastics, they can lead to a failure of the component. They are often accompanied by small arcs that, in the event of uneven contamination, can bridge well-isolating areas.
Ensinger offers a wide range of plastics with good properties for electrical insulation. It should be noted that, for example, the electrical properties are influenced by the moisture absorption of a plastic. This must be taken into account, especially in the case of plastics with high moisture absorption such as polyamide (see more here).
Our technical service is also available to advise you on the selection of materials.
To complement our products, we offer a comprehensive range of processing methods as well as customised profiles and tubes to meet your individual requirements for your finished part.
For detailed information, please contact us via our contact form.
