Compression Force Deflection

Applications that experience periodic compression cycling over time may require a gasket that is capable of compression rebound. In the event that your application uses a material that does not resist compression force, the material may depreciate over time. When your gasket has dwindled or has deteriorated from all of the periodic compression cycling, your gasket will become ineffective and will need to be replaced. In a perfect world, your gasket should rebound to fill any potential gaps. Using a material with great compression resistance will guarantee a long-term sealing performance that will work just as effectively each time you reseal your application.

PVC (Vinyl) Foam is the last foam variety that we will explore in our blog series "Foams for Low Clamping Force Seals".  PVC Foam is a lightweight closed-cell foam material.  It is often used for sealing out water, dirt and air.  It resists weathering and is often laminated with adhesive to create a dynamic foam tape. 

XLPE Foam or Cross-linked Polyethylene Foam is the next material we will explore in our blog series, Foams or Low Clamping Force Seals.  XLPE Foam is a closed-cell material formed of polymers or molecules bonded together (cross-linked).  The strength of these molecule bonds is reflected in the strength of the material.  XLPE foam can stretch, bear loads and return to its shape.  It works well in insulation, gap filling and gasketing applications. 

Light Density Polyester and Polyether Urethane Sponges and Foams have an open cell structure.  The evenly spaced structure of these materials and high proportion of open cells make them suitable for an infinite number of applications. 

As we explore different categories of foams that are used for Low Clamping Force Seals in this blog series, we move to Closed Cell Neoprene and Sponge Blends.  As stated in the previous post, closed cell materials do not allow moisture to pass through, making them good materials for general sealing and gasketing applications.  Keep reading for additional features and benefits 

What is Closed Cell EPDM Sponge?

Closed Cell EPDM Sponge is the third material we will explore in our blog series:  Foams for Low Clamping Force Seals.  EPDM stands for Ethylene Propylene Diene Monomer. "Closed Cell" describes the material at a microscopic level. The material is made with tiny bubbles that are inflated with gas, resulting in a closed cell structure that will not allowing moisture to pass through. This is what makes this material excellent for sealing and gasketing. EPDM is commonly used in the automotive and construction industries for various seals and gaskets due to its excellent environmental factors such as UV, Ozone and weathering. When comparing EPDM to Silicone, EPDM falls short when it comes to temperature resistance.

Features and Benefits of Closed Cell EPDM Sponge

• Non-crystalline material. Contains no plasticizers that can migrate and lead to premature membrane failure.
• Can be formulated in a variety of combinations with other polymer modifiers.
• Performs well in the -40°F to 175°F temperature range.
• Excellent moisture resistance, does not absorb fluids easily
• Used in many applications that require water, UV, ozone, or indirect sunlight resistance (superior to neoprene in this regard)
• Does not meet UL flame rating without additives and will not withstand oil and fuels.

We are continuing with our blog series: Foams for Low Clamping Force Seals. This week we will review the features and benefits of Microcellular Urethane Foam.  Along with the many benefits this foam offers for low clamping force seals, it die-cuts cleanly and adheres to a broad range of pressure sensitive adhesives. 

Adding a gasket to seal a device, whether it is keeping out dust, air, water, or something else, seems like it would be an easy part of design.  However, there are a multitude of material options available for most applications.  Choosing the right one may require some research.  This is why we are starting a blog series outlining the features and benefits associated with the many foams that fit into this large subset of gasket material options:  Foams for Low Clamping Force Seals

We are starting this series with SILICONE FOAM