Which Elastomer Offers The Best Low Temperature Flexibility?
When a product or component is required to operate in a low temperature environment, it is important in many instances that a base elastomer is chosen which offers a sufficient degree of low temperature flexibility.
This comes given that elastomer performance becomes less predictable near the limits of its service temperature range, however it is often one of the most overlooked properties, yet one which can be crucial to optimal performance.
Low temperature applications are common in industries including:
- Pharmaceutical
- Chemical
- Automotive
- Petroleum
- Textiles
- Electronics
- Aerospace
When operating at low temperatures:
- Elastomers become harder and less flexible until, at the brittle point, they may crack.
- Elastomers can lose their rubber-like properties, with the TR-10 (temperature of 10% retraction) reflecting the ability of a material to retract (behave like rubber) at low temperatures.
- Fluid may penetrate a component and act as a plasticizer, lowering the brittle point below that experienced in dry air.
- Changes which occur are physical, not chemical and, as such, may be reversible, however any movement whilst cold and inflexible may result in damage.
As such, when selecting the correct material for use when an end product will be required to operate in a low temperature environment, base elastomer selection is key to ensure optimal performance.
rubber sheeting, reinforced rubber sheeting and rubber coated textiles, utilising the correct base for each individual project, dependent upon both the operating environment and also the performance requirements. Whilst these 12 are most often used as a base material, in many instances it is necessary to manufacture a blend or formulation specific to the end product or component in question, with the characteristics of a material being able to be improved through the use of additives.
Below you’ll find a comparison of our 12 most commonly utilised elastomers based upon their low temperature flexibility, rated ‘poor’ to ‘excellent’:
Please note: Whilst most main rubbers are outlined below, our capabilities and experience allow us to manufacture a much wider range of blends and formulations. The inherent characteristics of a polymer can be improved through the inclusion of additives, including the low temperature flexibility.
| Elastomer | Low Temperature Flexibility |
| Silicone | Excellent |
| EPDM | Good / Excellent |
| Butyl | Good |
| Natural Rubber | Good |
| Polyurethane | Good |
| SBR | Good |
| Thermoplastic Elastomer | Good |
| Hypalon | Fair / Good |
| Neoprene | Fair / Good |
| Nitrile | Fair / Good |
| Vamac | Fair |
| Viton | Poor / Fair |
When it comes to selecting the most suitable base elastomer when low temperature flexibility must be a key characteristic of a product or component, we can clearly see that, when specifically looking at this single characteristic, silicone is the most attractive option, offering an excellent level of flexibility when operating at low temperatures.
Silicone stays flexible at the lowest temperatures of all elastomers, without noticeable change in its properties. When silicone is compared to other elastomers, it is clearly seen that it stays elastic at lower operating temperatures whilst other such materials become brittle, as would be expected.
Looking at the wider scope of the usage of silicone as a base elastomer for products and components which are required to operate in low temperature environments, it is also the case that the material offers a wider range than most, with operating temperatures of between -60 and 300ºC, meaning it is not only able to be utilised in temperatures as low as -60ºC but also in temperatures as high as 300ºC.
As a whole, silicone as a material has been proven to be more resistant to degradation, does not become soft and irreversibly deform when subjected to low temperatures, is naturally flexible at low temperatures and can withstand compression set. In addition, the material offers excellent resistance to ozone, oxygen, UV, moisture and fungus as well as offering excellent vibration damping and maintains its dielectric strength. Silicone is also generally odourless and non-toxic, making it suitable for use in a whole host of different applications.
Common applications of silicone include:
- Gaskets
- Seals
- O-Rings
- Fabricated Products
In many instances, the correct base material for use in the manufacturing of a product or component for low temperature environments will need to be a compromise between a number of different characteristics and properties including both the usage specification and the economics.
Although silicone technically stands up it is also relatively expensive when compared to other options. Alternatives such as EPDM may therefore become a prime candidate.
For detailed and in-depth, backed up information and data surrounding the suitability of a particular elastomer for use in a specific environment which may result in a requirement to operate at a low temperature, we welcome you to give our technicians a call on 01524 585200 or email us on [email protected] where we will be only more than happy offer guidance and assistance or discuss in more detail a specific project.
