Presspahn Washers

Presspahn Washers

Presspahn Washers

Advanced Seals & Gaskets Ltd stock sheets and rolls of Presspahn materials ready for supply or conversion - one of which is our Presspahn washers.  Presspahn is just one of a selection of electrical insulation materials used by ASG for the production of washers.  

Presspahn is also known in the industry as pressboard, press paper and elephantide.   As with other electrical insulation materials, Presspahn doesn’t allow the free flow of electrical current,  protecting electrical conductors from coming into contact with people or tools during installation, repairs or when an electrical appliance or device is being used.   Presspahn electrical insulation materials are manufactured in a paper form on a roll available  in thicknesses from 0.13mm to 1mm thick and also in rigid board from 0.5mm to 25mm from which washers can be  cut.    

As well as selecting a suitable material, the quality of the cut is also major factor in producing a reliable and perfectly fitting washer, therefore we ensure our in-house manufacturing team follow our customers drawings or samples which detail the Outer Diameter (OD), Internal Diameter (ID) and the thickness, in order to create an exact match reducing the risk of the washer failing when it is placed within its application. 

A combination of a skilled workforce and high spec machinery including a range of presses and CNC machines allows us to produce Pressphan washers in a wide range of sizes and quantities with or with self adhesive faces.

Product Enquiry

For information on Presspahn Washers please complete the following quick enquiry or call us on +44(0)1384 252555.

    Characteristics of Presspahn Electrical Insulation

    • Colour: Natural/brown
    • Thickness- Presspahn Paper: 0.13mm - 0.5mm
    • Presspahn Board: 1mm - 25mm
    • Density: 1-1.3g/cm
    • Voltage Strength (in oil): 35-40Kv/mm (depending on thickness)
    • Temperature:  105℃

    Full technical data can be supplied upon request,
    or downloaded from our online portal.

    What are Presspahn Washers?

    Electrical insulation Presspahn washers are formulated to create barriers, restricting the free-flow of electrical current.

    Presspahn materials are produced using electrical grade kraft wood pulp, designed as a surface insulation material on cellulose for insulation class A and can withstand high heat exposure for short periods of time.

      Presspahn materials are available in paper and board form, in a choice of different thicknesses both of which can be used to cut washers.  Presspahn Washers are a flattened ring  material which are placed between two surfaces in order to reduce friction, and unsteadiness and in this case to create an insulating barrier.


    Why use Presspahn Washers?

    Like other washers made from Electrical Insulation materials, those made from Presspahn papers and boards are manufactured for use as electrical barriers, restricting the free flow of current, protecting electrical conductors from coming into contact with tools and people during usage, repairs and installation. 

    Applications in which washers cut from Presspahn papers can be found include insulation within cables carrying electrical current or signals such as telephone cables, power cables, capacitors and even submarine power cables, whereas those made using presspahn boards are more often found as transformer boards in oil-filled transformers as an insulating structure. 

    Other Types of Electrical Insulation materials available

    Advanced Seals & Gaskets work with a multitude of material manufacturers, giving our customers more choice and ensuring we can offer a solution to just about any application. When it comes to Electrical Insulation materials, our most popular alternatives to Presspahn washers include:

    • Epoxy Glass - a green coloured material with good mechanical strength, good chemical, electrical and radiation resistance, low moisture absorption and a working temperature range of upto +120℃.
    • Kapton - is a polyamide film which offers a combination of mechanical and tear strength along with chemical, electrical and thermal properties that enables the gasket to withstand vibration and extreme temperatures in demanding environments.
    • Leatheroid - is a grey/blue coloured paper gasket material, also sometimes called Elephantide.  This material is used within the electrical industry to insulate hot elements.
    • MYLAR is an extremely strong, flexible polyester film.  MYLAR is an excellent insulation material with dielectric strength, moisture resistance and is an excellent insulation material.
    • Nomex can be manufactured using nomex paper or nomex board, it can withstand high temperatures, has high mechanical and dielectric strength, and is  an excellent insulation material for all kinds of electrical equipment and applications.
    • Mica is made by bonding layers of mica paper together with a resin, which are cured into a choice of rigid or flexible boards, which can be used to restrict the flow of electric current, by supporting electrical conductors - without allowing the current to pass through.
    • SRBF is resin bonded fibre material which is tough and rigid, with an operating temperature of 120℃, low water absorption and is resistant to wear, impact chemicals.
    • SRBP (synthetic resin bonded paper) is manufactured using layers of paper and synthetic resins.  This material is suited to high and medium voltage application.  SRBP has good mechanical and excellent electrical insulation properties, with low water absorption.
    • Valox is an excellent electrical insulation material which also offers flame retardant properties.
    • PTFE is a non- conductive plastic material used to produce electrical insulation sheets.  PTFE sheets are suitable for high temperature applications and have a high melting temperature.  This material has excellent dielectric properties and can be often found used in circuit boards.
    • PVC is a tough, lightweight abrasion, chemical and moisture resistant material which has good dielectric strength making it a great material to use for electrical insulation applications.

    Benefits of using Presspahn Washers

    • Can withstand high heat for short periods of time high
    • Utilised in 105ºC rated (Class A) electrical applications
    •  Excellent mechanical strength and absorption characteristics
    • Can be punched, folded and cut
    • Good machinability
    • Available in rigid board or flexible paper

    Advantages of Using Presspahn Electrical Insulation Washers

    Presspahn washers are found highly utilised within transformer and other power transmission equipment offering an excellent insulating structure.  Presspahn washers offer properties including resistance to ageing, insulation performance and mechanical properties and are available in a choice of rigid board and paper variants.  Presspahn can be taken in full rolls or sheets of material for conversion into washers at a later date but the customer or end user, or alternatively sawn, routered and pressed into bespoke washers here onsite at Advanced Seals & Gaskets Ltd.  

    During the formulation of the raw material, the compound is treated through several non-chemical processes, ensuring maximum purity free from fillers and impurities allowing for the washers to be used in even more stringent applications.  Presspahn Electrical Insulation washers offer excellent mechanical strength and oil penetration therefore suitable for both dry and oil based transformers and other equipment and can be used across a range of currents and voltages. 

    Some of the applications in which Presspahn washers can be found include insulation within cables carrying electrical current or signals such as telephone cables, power cables, capacitors and even submarine power cables, whereas those cut from presspahn boards are more often found as transformer boards in oil-filled transformers as an insulating structure.


    Have a Question about Presspahn Washers?

    Please contact us using the form below or by calling us on +44(0)1384 252555.