At NEDC, we cut all kinds of cellular sponge products. One thing we have never really discussed on this blog, is “What is Open Cell Foam?” We discussed the differences between Open Cell Sponge, and Closed Cell Sponge, but I thought to myself, maybe a more comprehensive blog could be required.
What is Open Cell Sponge/Foam?
Open Cell Sponge/Foam is a material class that has cells that are blown similar to closed cell, but are not completely closed off like closed cell sponge. This means a few things:
- The compression set is usually not as bad because theres less material to take a set.
- The water sealing properties are not as good comparatively to closed cell materials. However, open cell materials can seal under more compression.
- They do compress a lot easier in general. With less material to compress, it’s easier to do it. As an anecdote, we use open cell materials mostly for our ejection during die-cutting.
Designations/Specifications for Open Cell Sponge
ASTM D1056 is pretty simple when it comes to the difference between Open Cell, and Closed Cell materials.
A typical callout for ASTM D1056 looks like this:
ASTM D1056 2D3
ASTM D1056 1C1
ASTM D1056 1A1
The first number in the callout means that its either closed, or open cell. “2” means closed cell, well “1” means open cell. So ASTM D1056 1A1, and 1C1 are open cell materials.
Another specification that designates open cell from closed cell foams is ASTM D6576.
ASTM D6576 has open cell and closed cell designated by Type I, and Type II respectively.
Types of Materials for Open Cell Sponge
Natural Rubber Open Cell Sponge
RO-11, ASTM D1056 1A1
RO-12, ASTM D1056 1A2
RO-13, ASTM D1056 1A3
EPDM Open Cell Sponge
-EnsoLite EF0, ASTM D1056 1A0
PORON® Polyurethane by Rogers
-Most PORON® materials are open cell. These materials are designed to take less of a compression set but also be very versatile for general space taking as pads, and for general sealing- for example for dust.
PVC-Nitrile Sponge
-EnsoLite SF0, ASTM D1056 1A0
More Information on Open Cell Sponge/Foam Gaskets
Standard colors for open cell sponge/foam materials are either color black, or color tan. Thicknesses for 1/16’’ , up to 1’’ thick is what is available for these materials. NEDC does die-cutting, and waterjet cutting for custom gasketing parts, or shock absorption pads. For more information on cellular sponge, and gasketing- please contact sales@nedc.com.