Electrical insulating materials

Tufnol materials are synonymous with the electrical industry.

 From the early pioneering days of insulation to the present day, Tufnol has played an enormous part in ensuring safety in the critical operation of low, medium and high voltage electrical equipment.


High temperature electrical insulation

With over 80 years of experience in the electrical industry, our paper based phenolicfine weave cotton epoxy, and woven glass epoxy grades all possess excellent dielectric strength in the most demanding environments.

Paper based phenolic grade

Originally developed for use as a superior rigid electrical insulation material in heavy duty switchgear in the 1920’s, our famous Kite Brand Tufnol is still manufactured today in large quantities to satisfy the requirements of today’s modern electrical industry.

It is the most widely used of all Tufnol phenolic paper grades and is put to use in a multitude of different applications including busbar supports, coil formers, insulating sleeves, mounting panels, insulated enclosures and a myriad of punched parts.



Paper based phenolic grade

Our superior epoxy cotton laminate, Tufnol Grade 6F/45, has
a unique combination of properties.

Using a specially modified epoxy resin system, this material possesses
high insulation resistance and electrical strength and an exceptional
resistance to surface electrical tracking.

This versatile grade is mechanically strong, has low water absorption
and excellent dimensional stability which enables it to be machined to
a superb finish and very close tolerances – not surprising therefore that it is generally regarded as the ‘Rolls-Royce’ of cotton laminates!

Woven glass epoxy grade

The woven glass epoxy grades in the Tufnol range are truly high
performance in terms of electrical strength.

Using a variety of advanced resin formulations, our group of materials in this range are characterised by very high strength properties and
dimensional stability.

The range includes grades with exceptional temperature resistance, first
class dielectric properties, good resistance to surface tracking, assessed flammability and superb structural strength and toughness. These high performance materials are used in applications such as insulation in
large turbine generators, components in cryogenic superconducting
magnets, jigs for electrochemical machining, rail/fishplate insulation, and
structural insulation for electronic equipment.

Benefits of using Tufnol

High insulative resistance
Outstanding electrical strength
Low water absorption
Excellent dimensional stability


Products & applications

Dangers of Electrical Tracking or ‘Treeing’

Insulator tracking refers to partial electrical breakdown along the surface of an electrical insulating material, and the formation of permanent partially-conductive paths (“tracks”) across a portion of the insulator surface. Tracking typically occurs across an insulating surface that has been subjected to prolonged high-voltage stress without the correct selection of insulating material. As these tracks develop, they often resemble ‘tree’ patterns on the insulation material

Over time this tracking can lead to an electrical arc between conductors which can cause catastrophic failure of equipment and likely result in a fire. Thus it is vital that materials used for electrical insulation are appropriate for the equipment.

Our customers include

Interested in finding out more about the applications of our materials?


Quality is an integral part of our culture

Our quality systems are routinely subjected to scrutiny by a number of independent inspection authorities and major international companies.


Our capabilities

Tufnol Composites has a large machining facility for the production of finished machined components from the above materials. Tufnol machine shops are equipped with advanced technology and have the capacity to meet a very wide range of customer requirements.

These include

Why Tufnol?

100 Years in business
Fast, efficient service
Top quality materials
On site manufacture

Speak to the team