NBR? HNBR? Viton? FKM? MVQ? ...
What material should I choose now?
In this article we summarise the most important things to know!
Choosing the correct rubber material is crucial in the field of sealing technology. Seals are components that prevent the flow of liquids or gases between two or more connected surfaces. Therefore, it is essential to select the appropriate rubber material for seals to ensure effective and reliable sealing.
Choosing the correct rubber material primary consideration in sealing technology is chemical compatibility. The materials, fluids, or gases present in a given environment or application can have different effects on rubber materials. For instance, if a seal is exposed to oils, acids, alkalis, or other aggressive substances, a rubber material must be chosen that can resist these chemicals without eroding or swelling.
The second important factor is operating temperature. Seals must withstand temperature fluctuations without compromising their properties or efficiency. Different rubber materials exist that are specifically designed to function effectively in high-temperature or low-temperature environments.
Other factors include pressure resistance, wear resistance, UV resistance és weather resistanceSelecting the optimal rubber material takes into account these characteristics, ensuring long-lasting and reliable sealing performance.
In conclusion, choosing the correct rubber material is vital in sealing technology to achieve effective and reliable seals. Considering factors such as chemical compatibility, temperature resistance, and other properties enables the seals to function optimally and have a long service life.
The following table summarises the main types of materials and their main characteristics. Keeping these in mind will make it easier to choose.
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Main properties and characteristics of the most commonly used vulcanised rubber types |
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| NBR (Nitrile rubber) |
HNBR (Hydrogenated Nitrile Rubber) |
Silicone (VMQ, MVQ) Vinyl silicone |
Viton (FKM, FPM) (Fluorine rubber) |
EPDM (Ethylene-Propylene-Diene Rubber) |
|
| Hardness (Shore A) | 60-90 | 60-90 | 60-90 | 60-90 | 40-90 |
| Heat resistance (°C) | -50 – +100 | -30 – +150 | -55 – +210 | -25 – +200 | -40 – +150 |
| Tensile Strength: | good | excellent | poor | medium | good |
| Elongation | good | good | excellent | medium | good |
| Resilience: | medium | medium | good | insufficient | good |
| Tear resistance | medium | poor | not recommended | not recommended | medium |
| Wear Resistance/Abrasion resistence: | excellent | excellent | not recommended | poor | good |
| Residual deformation | medium | medium | insufficient | insufficient | not recommended |
| Gasoline | medium | medium | not recommended | excellent | insufficient |
| Mineral oil | excellent | excellent | medium | excellent | insufficient |
| Inorganic acids | medium | medium | medium | excellent | not recommended |
| Inorganic alkalis | poor | medium | not recommended | excellent | poor |
| Hot water | medium | good | medium | excellent | poor |
| Ozone, weather | not recommended | excellent | excellent | excellent | poor |
| Application environment and resistance characteristics | Vegetable and animal oils and fats, mineral oils and fats, (fuel, fuel oil), dilute acids, alkalis, brines, water, air, gases (butane, ethane, methane, propane), hydraulic oils. NOT resistant to: aromatic and chlorinated hydrocarbons, glycol-based vehicle brake fluids and ozone contamination. | Resistant to oils and greases as in NBR materials and to hot water up to 100 °C, good resistance to hypoid gear oils up to +130 °C. NOT resistant to: aromatic and chlorinated hydrocarbons, vehicle brake fluids. | Glycol based brake fluids, high temperature air, oxygen, hot water, high molecular weight chlorinated aromatic hydrocarbons. NOT resistant to: concentrated acids and alkalis, water above 100°C, steam. | High temperature vegetable and animal oils and fats and mineral oils and fats, various chemicals (aromatic, aliphatic, chlorinated hydrocarbons), highly oxidising acids, vacuum, petrol. NOT resistant to: acetone, amines, alkalis, vehicle brake fluids, acetic acid, hot water and steam. | Hot water, steam, air, vehicle brake fluids up to 150 °C, glycol-based fluids, dilute acids, alkalis. Excellent abrasion resistance, resistance to ozone, UV and ageing. NOT resistant to: any petroleum products (lubricants, fuels) and hydrocarbons. |