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Principles of Electrical Insulators

  • Electrical insulators are manufactured from materials that restrict the flow of an electrical current

  • Support electrical conductors without letting current pass through

  • Protect electrical conductors from coming in contact with people

  • Known for their ability to insulate electrical current, withstand moisture/corrosion, and resist arc and flame.

Electrical Insulator Materials We Offer:

  • Polycarbonate

  • Nomex

  • Formex

  • Abs

  • Phenolic

  • G10/Fr4 (Fiberglass Epoxy sheets)

  • GP0-3 (polyester glass)

  • Delrin


Nomex Type 410 is the original form of Nomex paper (by DuPont). It is a high temperature aramid paper. Nomex insulators have high dielectric strength, mechanical toughness, flexibility and resilience. They are used in the majority of electrical equipment applications. Nomex is self-extinguishing, tear resistant, formable, heat barrier, and electrical insulator.  It can also resist temperatures ranging from     -320˚F to 570˚F.  Thicknesses we offer range from .05” – .030”

Formex (Formex, Formex  GK)

Formex offers great flexibility and durability for a variety of uses.  It can be used as a barrier to protect users from electrically charged components, while safe guarding sensitive electronic parts from damage.  It offers exceptional dielectric strength, high temperature rating, and great chemical and moisture resistance.  Formex provides lightweight, flame retardant protection while meeting strict safety and environmental standards at a low cost.  For applications where Formex will be exposed to temperatures 239˚F, we suggest using Formex instead of Nomex due to the reduced cost.

Plastics for Electrical Insulators

  • B.S.: or Acrylonitrile Butadiene Styrene is known for its toughness and impact resistant properties.  It’s easily Machined and high di electrical strength.  Commonly used in electrical housings, computer housings, support blocks, and structural components.

  • DELRIN: Have uses similar to nylon. The material is rigid and has excellent mechanical and electrical properties making its use common in appliances and electronics.

  • G10/FR4 (epoxy/fiberglass): This laminate is very common due to its superior strength and excellent electrical properties even in humid environment. Most modern circuit boards are made from a grade of epoxy/fiberglass. G10/FR4 consists of a filament glass cloth material with an epoxy resin binder. It has high strength and excellent electrical properties. G10/FR4 also provides chemical resistance at room temperature as well as under humid or moist conditions. Also offers dimensional stability, outstanding insulation properties, high tensile strength, and low moisture absorption.

  • LEXAN (polycarbonate): have excellent electrical insulating properties. Has high Optical properties and is so tough that it meets U.L. requirements for burglary-resistance. Machined to make strong insulators, electrical guards, machine guards, and electrical insulators.

  • PHENOLICS: Phenolic is widely used for terminal boards, connectors, boxes, and components.

Electrical Insulators: About
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