In various rubber sheets, there are EPDM and FKM rubber sheets that have the performance acid-alkaline resistance. This article will introduce and explain how to choose these two kinds of rubber sheets.
This article will be composed of two parts, the first part introduces the performance of the EPDM rubber sheet and FKM rubber sheet in acid and alkali resistance. The second part introduces the other characteristics of these two rubber sheets.
Performance Comparison in Acid and Alkali Resistance
About acid and alkali resistance, FKM is resistant to inorganic acid, resistant to most organic and inorganic solvents, resistant to strong oxidation of inorganic acids such as fuming nitric acid, concentrated sulfuric acid has a high chemical resistance to organic liquids, concentrated acids, high concentration of hydrogen peroxide, and other strong oxidants.
EPDM has good resistance to various polar chemicals such as alcohols, acids, bases, oxidants, refrigerants, detergents, animal and plant oils, ketones and lipids. However, it has poor stability in lipid and aromatic solvents (such as gasoline, benzene, etc.) and mineral oils. Its performance will also decline under the long-term action of concentrated acid.
All in all, FKM rubber has a high degree of chemical stability and is the best medium resistance among all elastomers at present. It is chemically more stable than any other rubber when dealing with organic liquids, concentrated acids, high concentrations of hydrogen peroxide, and other strong oxidants.
Other Performances and Applications
Regarding other properties and applications of EPDM and FKM rubber sheets, the most outstanding performance of FKM is that it has excellent heat resistance and oxidation performance, which can be comparable to silicone. FKM has heat resistance, oxidation resistance, oil resistance, corrosion resistance and atmospheric aging resistance, and has been widely used in the fields of aerospace, aviation, automotive, petroleum and household appliances, and is an irreplaceable key material in the cutting-edge industry of national defense. The relative shortcomings also have the following, poor cold resistance, tensile strength decreases quickly with the increase of temperature, the price is very expensive, and the processing performance is not good.
EPDM has ozone resistance, heat resistance, weather resistance, excellent aging resistance, can be widely used in automotive parts, building waterproof materials, wire and cable sheath, heat-resistant hose, tape, automotive seals and other fields. The relative shortcomings also have the following, low cohesion energy, glue is easy to spray frost, so self-adhesion and mutual adhesion is poor. And it is poor stability in aliphatic, aromatic and mineral oils. Under the long-term action of concentrated acid, the performance will also decline.
Summary
In genernal, EPDM rubber sheet is resistant to the general degree of acid and alkali, but its resistance to the high concentration of strong acid and alkali is not good. To resist this high concentration of acid and alkali, FKM rubber can be chosen.