Preventing Gasket Failure: Solutions for Compression Set in Die-Cut Gaskets
When manufacturing gaskets, understanding compression set is vital for ensuring long-lasting performance. If a gasket loses its original thickness due to constant forces and pressures, gaps can form. These gaps may allow fluids or gases to leak, leading to potential equipment failures.
In this article, we’ll address your most pressing questions about compression set and guide you in selecting the right materials.
What is Compression Set in Gaskets?
Compression set refers to the permanent deformation that can occur in foam gasket materials. Designed to compress, these gaskets create a dense barrier that effectively seals out moisture, dust, and other contaminants.
Over time, continuous pressure can permanently alter the foam, resulting in an indentation. This means the gasket doesn’t return to its original thickness when the enclosure is opened. In essence, compression set happens when a material remains deformed after being subjected to pressure.
How is Compression Set Measured?
Compression set is measured as a percentage. As you compare materials, a lower percentage indicates the material can better withstand long-term pressure without becoming permanently deformed or taking a compression set.
Choosing the Right Materials: What is an Acceptable Value for Compression Set?
Choosing an acceptable compression set value depends on the application and material used. In general, a compression set value of less than 25% is considered adequate for most gasketing applications. However, critical sealing applications, such as medical devices, might call for a lower compression set value of 10%. The same is true for reclosable seals.
For further reading: PORON Selection: Choose the Right Product to Achieve Compression Set Resistance
How is Compression Set Calculated?
Compression set is calculated by measuring changes in the material’s thickness after it’s been compressed. The calculation is based on the material’s original thickness, recovered thickness and and the thickness of the material in a compressed state (test thickness), using the following formula:
Compression set % = original thickness – recovered thickness/original thickness – test thickness x 100
As with many material properties, compression set is evaluated using standardized conditions, so that all materials are tested under the same conditions, including temperature, compression level and duration. These methods are outlined by ASTM D395 in the U.S., and DIN 53517 in Europe.
It’s important to note that the compression set values listed in technical data sheets may differ from real-world applications due to controlled lab testing. Use this data to narrow your selection, but always test prototypes to identify the best fit for your specific needs.
SRP offers rapid prototyping so you can launch test use cases immediately.
Should you Opt for the Lowest Compression Set for your Die-Cut Gaskets?
While it may seem logical to select materials with the lowest compression set for durability, we recommend considering overall value for your specific application. Sometimes, a more affordable material with a higher compression set can perform just as well, making the higher cost unjustifiable.
Our promise at SRP is transparency; we’ll inform you if you’re overspending based on our expertise. Learn more about SRP’s time-tested strategies to control your die-cut gasket costs.
How to Choose the Best Material Based on Compression Set
Selecting the right material to address compression set requires real-world testing to ensure performance under intended conditions.
For reclosable seals—like those on doors or detachable units—a soft material with a low compression set is ideal, as these materials can spring back to their original shape after being compressed.
In contrast, many permanent enclosures perform well with materials that have a higher compression set. However, if these enclosures are opened for repairs or cleaning, it’s essential to inspect the gaskets regularly and replace them as needed for optimal sealing performance.
To get more insight on SRP’s added value as you refine material selection, download our case study on our resources page: Identifying the Right Gasket Material to Restore Function to a Gas Detector.
Top-Quality Die-Cut Gaskets: Customized to your Application
At SRP, we combine material expertise with advanced manufacturing techniques to create gaskets that deliver reliable, long-lasting performance. Contact us today to discuss your latest project.