When choosing rubber gasket material it’s important to consider chemical compatibility. What’s sometimes overlooked though is that compatibility relates to more than just the fluid being sealed. Cleaning agents and solvents that will come into contact with the sealing material must also be considered.
One widely used cleaner/solvent is acetone. While compatible with some types of rubber, it reacts negatively with others. Here’s what to consider.
Although perhaps best known as a nail polish remover, acetone has many other uses. It’s a key ingredient in lacquers used in the automotive and furniture industries, it’s used in some textile manufacturing, and it’s an industrial cleaner, particularly in the printed circuit board sector.
Chemists classify acetone as a ketone. It’s generally harmless to humans, although is very flammable. However, it will damage some types of rubber.
Rubber Takes Many Forms
In its original sense, “rubber” refers to an elastic material made from the sap of the rubber tree. Today though it’s often used as a general term for almost any elastomeric material.
The closest materials to natural rubber are SBR or red rubber, and NBR, also known as nitrile and Buna-N. (These were originally developed as synthetic forms of natural rubber.) Then there are other elastomers like neoprene, EPDM, silicon and FKM/Viton® that behave in similar, often superior, ways to natural rubber. All these are sometimes lumped under the heading of “rubber”. This causes a problem because they react differently to chemicals like acetone.
Positive and Negative Compatibility
The good news is that acetone won’t react with or degrade EPDM. Unfortunately it reacts negatively with many other rubber-like gasket materials.
With natural rubber, SBR and neoprene, the degradation is minimal: brief exposure is unlikely to cause any problems. However, in NBR and FKM/Viton it causes swelling which can quickly lead to failure of the seal. For this reason these types of rubber are best kept away from acetone.
If in Doubt, Ask an Expert
Material compatibility is an important part of gasket material selection. If you have any concerns, contact us and speak with a specialist.