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Everything You Need To Know About Foam Gaskets

What are gaskets, and why is foam a good gasket material?

A gasket is a (usually) flexible component, inserted between the join of two surfaces, for various reasons, including:

  • Preventing the seepage of liquid, air or gas
  • Reducing vibration or sound
  • To reduce fluid loss in mechanical equipment
  • To aid the sealing process

What are gaskets made from?

Gaskets are made from a range of materials, including cork, rubber, paper, metal, such as copper, and of course, foam. Each of these materials has particular benefits, which are often purely practical, or sometimes, economical.

Practical reasons for gasket material choice comes down to:

  • Chemical, alkaline or acid resistance
  • How the material reacts in extremes of temperatures
  • How the material reacts under extremes of pressure, particularly in deepwater environments

Which industries are gaskets used in?

Most of today's industries benefit from gaskets in some way or another, whether directly or indirectly. The more obvious industries include automotive, petrochemical, pharmaceutical, water, gas, mining (including deep sea), and the food and drinks manufacturing industry.

How does a gasket work?

Simply put, a gasket works by creating an airtight or liquid-tight barrier between one surface and another. To achieve this barrier, the gasket needs to be compressed, so it can reach its maximum efficiency.

Once in place, the gasket allows liquid or gas to pass freely through the joint, without the risk of leakage, or contamination from external liquids or gas. As mentioned above, a gasket can also act as a sound barrier, as well as an anti-vibration component.

Why is foam a good gasket material

To answer this question, it’s important to first understand what we mean by foam, when used in the manufacture of foam gaskets, foam bungs, foam plugs or foam spacers.

The foam we’re talking about is EPE (Expanded Polyethylene) foam, which generally speaking, is a closed-cell foam, meaning each cell in its construction is like a tiny, sealed nitrogen-filled bubble.

This closed cell state, and many other features of EPE foam, makes it an extremely good gasket material for several reasons, including:

  • Foam is chemical resistant - Chemical resistance is a vital feature in many types of gaskets, particularly those used in the petrochemical and pharmaceutical industry.

    Foam, such as ZOTEK® N, provides extremely good chemical resistance, especially to oils, including brake, power steering and antifreeze fluids, hydrocarbons, and most fuels, making it a vital gasket material to the automotive industry.

  • Foam has antivibration features – Antivibration is essential in a wide variety of industries, especially the aerospace or aviation industries, where excessive vibration of certain components can cause serious malfunctions.

    Closed-cell foam such as Plastazote is regularly used in the manufacture of components, including gaskets and spacers, for the aerospace and aviation industry, due to its ability to perform, even under constant vibration.

  • Foam is easily formed – Gaskets in many industries, are required to be highly intricate in design, to ensure a snug fit between certain components, and provide the optimal performance in extreme situations.

    One outstanding benefit of foam, particularly EPE foam, is its ability to be formed into highly technical designs, and to close tolerances, using a variety of foam-forming processes, including: