Flexible Solutions

3 Questions Answered about Compression Set Resistance in Foams

Posted by Katie Sullivan

January 18, 2017 4:34 PM

When choosing a foam for a product design, one feature that should be considered is the compression set resistance of the foam.  C-Set is one of the most important characteristics to consider, and this blog post answers three basic questions to explain why. 


Compression Set Resistance is the ability of a foam to return to its original thickness after a compression load, under a specific time and temperature, is released.  Simply put, the compression set of a material is the permanent deformation remaining when a force (that was applied to it) is removed. 


The following describes the most common method: A foam specimen 0.50″ thick is compressed 50% for 22 hours at 158°F, the load is released and the foam is allowed to sit for 24 hours at room temperature. Then thickness is measured. Based on the thickness of the foam after the 24 hours, compression set is calculated as a % value.  The lower the % value, the better the Compression Set Resistance of the foam.

3.  SO WHAT?  

Compression Set Resistance is one of the most important characteristics of foam materials especially if the engineer/designer is looking for a medium or long product life cycle. A high C-Set indicates that the foam material is degrading and losing performance values. If the product is to be used once and discarded, then C-Set is not important. However, the longer the product is expected to perform, the more important C-Set is to the application.

To see a demonstration showing the compression set resistance of 4 different foams, check out the video below.   



Marian converts many different foams and has the experience and knowledge to help you chose the right foam for your application.  Contact us to help you with your next project.  

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Topics: Foams, BISCO Silicone, PORON, compression set resistance, Elastomers