Electrical Insulation: things to consider when choosing electrical tape

Electrical insulation is used in electrical engineering to separate parts through which an electric current flows, either between themselves or to prevent contact with such a part. It is also used to protect electrical equipment from external influences.

Electrical Insulation Tapes can be utilised in various types of industries, especially:

• Electric machines, motors and transformers
• Electronics
• Automotive electronic parts
• Within the new Electrical Vehicles Battery industry sector

When choosing the right insulation, we must pay attention to the two following parameters:

• Product Stability – Whether we mean mechanical strength, resistance of hot or cold temperatures, resistance to chemical or oil exposure or the key property of dielectric strength,  product stability is an important factor in its choice. The insulation must remain the same after a long time and for safety reasons must always have the same properties
• Weight and Dimensions – when choosing the right insulation, it is important to consider its weight and any specific dimensions. As with the choice of tape materials, selecting the best electrical tape thickness and width depends entirely on the application and the environment it is used in.

There are many types of Electrical insulation on the market today and many materials that we can use for it. PPI Adhesive Products offers a wide range of special tapes suitable for electrical insulation.

The exceptional properties of PPI Electrical Insulation Tapes:

• Mechanical Strength and Resistance
  • high mechanical strength and high performance
  • various types of materials and corrosion resistant adhesives
  • adhesives have high resistance to solvents, impregnating or molten resins and have good adhesion
• Heat Resistance: temperature range from -200°C to + 400°C
• The key property of Electrical Insulation materials is Dielectric Strength. It is defined by the type of material and its thickness. We usually want the dielectric strength to reach as high a value as possible, and those materials that are able to reach such a value have a wide range of applications, for example Nomex®, Polyester or Polypropylene.

Our products can be manufactured in a wide range of thicknesses, length and roll width, with various types of adhesive, double-sided/single-sided options, laminates, with/without a liner. Tapes are available in Printed or  Die-Cut pieces. Working closely with our R&D Department, we can provide innovative, bespoke solutions based on your ideas and specifications.

Guide to electrical insulation materials: which one to choose?

PPI Electrical Tapes are constructed from a complete range of backing materials:

Polyester Electrical Tapes

Electrical tapes based on polyester film exhibit very good dielectric strength combined with excellent mechanical strength. PET film can be used continuously at a temperature of 130°C (266°F). The film possesses good tensile strength, flexibility and chemical inertness to most solvents. PET film is rated as flame retardancy class UL 94 VTM-2. PET based tapes serve as general purpose film for electrical applications, such as phase separation of motors and core and inter-layer insulation of coils and transformers and slot insulation in general.

Nomex Polyamide Paper Tapes

Insulation tapes based on Nomex polyamide paper offer good temperature resistance, dielectric strength, mechanical toughness, flexibility, and flame retardancy. Polyamide paper is an excellent insulator designed to operate in the temperature range of 150°C to 220°C (302°F to 428°F). Nomex Mica Paper is used with high voltage equipment where corona is an issue. The flame retardancy is improved due to the mica content.

Applications: Insulation for bar wound armature, Phase and Layer Insulation, Coil Banding and Wrapping

Glass Cloth Electrical Tapes

Glass cloths are the most flexible and conformable backings used for adhesive tapes. Due to the glass fibers in the cloth (an inorganic material), it is non-flammable and high temperature resistant. Glass cloths can be used at a constant temperature of 180°C (356°F), and offers good solvent and chemical resistance.

Having excellent tensile strength, glass cloth tapes are widely used in applications such as insulation, inner and outer layer wrapping of electrical coils, and bobbins.

Polyimide Electrical Tapes

Polyimide tape is mainly preferred in applications where a durable tape with high-temperature stability is required.

Polyimide film has the best thermal properties of films available. It has no melting point and can be used over a temperature range of -269°C to 350°C (-450°F to 660°F) and constantly at a temperature of 240°C (465°F). Its physical properties are excellent and include high tensile strength, high resistance to creep, cut-through, abrasion, solvents and chemicals. It has high dielectric strength which makes it an ideal insulating material for use with high voltage. Polyimide film will resist radiation and ultraviolet light. Polyimide tape is generally flame-resistant and can withstand much higher short-term temperature than other electrical tapes.

Main Applications: Insulation for high-stress conditions in traction machine manufacturing, generator production; Outer wrap for transformers, toroidal coils, motor coils; Bundling of armature coils

Teflon™ PTFE Electrical Tapes

PTFE has a wide range of temperature use from -265°C to 260°C (-509°F to 500°F). It has superior resistance against all types of solvents, chemicals and stresses. Teflon displays high dielectric strength and is flame retardant, rated at 94 VTM-O. It’s flexible and conformable properties make it ideal for wrapping irregular shapes.

Tear resistant Teflon® (PTFE) film based electrical tapes are suitable for high temperature insulation for coils, transformers and motors. Laminated with glass cloth are suitable for cable harnessing at high temperatures, interphase insulation, core and coil lead anchoring and high temperature ground insulation. High quality glass cloth reinforced substrate combines excellent mechanical properties — tensile strength, puncture and tear resistance — plus non-stick / low friction characteristics of PTFE backed materials. The silicone adhesive also gives this product ideal high temperature performance and ideal long-term age resistance.

Acetate Silk Cloth Electrical Tapes

Acetate cloth tapes are used only for moderate applications, due to the fact that they cannot exceed 120°C (248°F). Among the main types of electrical tapes, cloth tape is generally less associated with strong dielectric properties, meaning it’s not the best choice for applications where insulation is the key factor. However it is prized for its mechanical properties. Acetate silk cloth electrical tapes are very conformable, flexible, hand tearable, printable and suited for varnish impregnation. The main application for these tapes is the outer wrap and identification of coils and relays. They are used for cable harnessing, lead holding and interwinding insulation where high mechanical strength is required.

Electrical insulation requirements in demanding environments are achieved using a unique combination of backings and adhesives.  

Need help with choosing right product? Visit PPI Adhesive Products website and get in touch with one of PPI regional sales representative www.ppiadhesiveproducts.com/contacts-ppi-worldwide.