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What is gasket paper?
A gasket sheet - often referred to as ‘gasket paper’, despite usually being made from silicone rubber, cork, nitrile or any other robust flexible material - is a large piece of sheeting intended to be used in making quick, cost-effective gaskets (seals), for joining surfaces or components together.
Gasket paper is sold in a wide variety of material types and thicknesses, with the best choice for any given application being entirely dependent on the nature of the task the gasket will be performing. In this guide, we’ll look at some of the different types and uses of gasket sheeting, and give a run-down of some of the various options on the market.
What is gasket paper used for?
In its simplest form, a gasket is really just a small part cut out of some sheet material, very often in an ‘o-ring’ shape, that helps form a compressible leak-proof seal between two surfaces or components. Gaskets are usually made from a robust, flexible, and/or chemical/heat/acid-resistant substance.
They’re most commonly used in pipework and ducting systems, where they’re called flange gaskets. Here they help join two sections of pipe together seamlessly to form a continuous, non-leak channel through which liquids or gases can flow.
Some gaskets are defined by their intended application, such as vehicle gaskets in the engines of cars, planes, boats and more. Others are defined by their physical composition and materials, or by the specific nature of the role they’re made to perform (such as acid resistance or high-pressure functionality).
Buying gasket sheets is a cost-effective way to enable the production of new replacement or bespoke gaskets quickly and easily, as older ones eventually begin to stiffen, degrade or fail.
Types of gasket paper and sheeting
Important considerations to factor in when choosing gasket sheet materials include operating temperature, pressure, chemical compatibility and long-term cost-effectiveness of more robust products over cheaper but less reliable alternatives.
There are many different types of gasket paper on the market, all of which have their own strengths and advantages when used in specific scenarios. In this section, we’ll go over some of the most common and widely available types of gasket sheeting.
Rubber gasket sheets |
Rubber gasket sheet is often thought of as a sort of ‘entry level’ or general-purpose gasket material. It offers good protection against the passage of most gases, and can cope with mild acids/alkalis fairly well. However, the properties of natural rubber gasket sheet material (along with that of most other elastomers) make it a broadly unsuitable choice for oils, fuels, or very high pressure/temperature applications |
Cork gasket sheets |
Cork gasket sheet is another commonly found choice for gasket paper materials, and it offers several key benefits - it’s relatively economical, easy to compress, and doesn’t react aggressively in contact with very many substances (it’s generally suitable for oils, fuels and solvents). While it does have excellent vibration-damping properties, cork gaskets are seen as somewhat lacking in mechanical strength, particularly under significant flex or torsion. |
Asbestos gasket sheets |
For that reason, nearly all asbestos components today are being replaced with materials cut from non-asbestos gasket sheets of other compressed fibre material, combined with elastomers for added flexible strength. They’re good for use in a wide range of tough applications including oils, acids and steam. |
Exhaust gasket sheets |
Nitrile cork and multiple variants of non-asbestos fibre are common materials found all over the exhaust gasket sheet market - along with a range of older graphite laminate formulas, although these can be somewhat more prone to blowouts. Other high-performance options include steel and copper reinforced gaskets. Whatever the material, it’s also important that exhaust gaskets offer good resistance to gas leaks, and are fairly easy to access and maintain. |
High-temperature gasket sheets |
One of the main challenges for high-temperature gasket paper material is that the better resistance to thermal extremes, the less flexible and compressible a material tends to be. Natural and silicone rubbers will struggle as the temperature rises beyond about 300 Celsius, whereas something like ceramic fibre can operate perfectly well at three times that - but the latter is very brittle compared to rubber seals, and therefore tricky to use in high vibration applications, or where leakage must be completely eliminated. Graphite laminates and compressed foils are also good choices for some high-temperature gasket sheets, which often tend to demand resistance to high pressure, saturated steam or hot oils too. Unsuitable material choices for any of these elements can quickly lead to gasket failure when intense heat is added to the equation. |
Nitrile gasket sheets |
Nitrile rubber gasket material is a fairly broad-spectrum type, useful in a wide range of applications. It’s particularly effective at protecting against leaks of water, oils, hydrocarbons and silicone greases, and offers better performance under high temperatures than neoprene alternatives. Nitrile rubber sheet suppliers also note that it’s relatively chemical resistant, but remains unsuitable for handling certain media such as strong oxidising agents, chlorines and ketones. Along with various other types of gasket paper, nitrile is available in sponge form too - these can be in open-cell varieties when compressibility is key, or closed-cell if leak prevention is the main aim. |
Silicone gasket sheets |
Silicone sheet gasket material is fairly temperature-resistant and extremely flexible, with excellent waterproofing and electrical insulation properties. This makes it a sensible choice for gasket papers that need to be used in outdoor applications or around any powered machinery/components that may come into contact with moisture, although it’s not well suited to withstand oils or steams. Like nitrile, silicone rubber gasket sheeting is also available in open-or-closed-cell sponge variants. Silicone gaskets are commonly found in food production environments when produced to the necessarily approved grade. |
Graphite gasket sheets |
Graphite gasket sheet is something of a traditional material for gasket production, but still very widely used in a range of environments and applications. The higher the carbon content of the graphite gasket paper, the more flexible it will be, but also more brittle. For this reason, high-carbon graphite sheet gasket material is often sold reinforced with various metal cores or fillers. Graphite gaskets are frequently found in high temperature or pressure environments, or where hazardous chemicals must be sealed away. Example industries include petrochemicals and refineries, steam services and vibration damping. |
Where to buy gasket materials and paper
When looking for where to buy gasket papers and gasket sheeting materials, it’s important to speak to a supplier that knows exactly which types of material to recommend for which specific applications.
RS Components stock a wide selection of high-quality rubber, nitrile, silicone and graphite gasket sheets, as well as various other materials in a range of thicknesses and surface areas, from industry-leading brands and manufacturers.
