Rubber materials are commonly used in shock absorbing and vibration dampening applications, but they can also be used for sealing and cushioning. Rubber materials are known for their flexibility, weather resistance, and cost effectiveness.
In this guide, we’ll discuss the top advantages, the different types, and how rubber material compare to polyurethane.
Components That Use Rubber Materials
Rubbers are commonly used for:
Outside of these products, rubber can also be used for:
- Gaskets
- O-rings
- A base for many products, such as bolts, to reduce vibration.
Machined plates, sheets, and cords of different rubber materials are also available.
Advantages of Choosing a Rubber Material
Excellent weather resistance and vibration dampening are two properties that rubber materials provide in an application.
In addition to these two properties, there are many other reasons to use rubber over other materials.
Here are the top benefits of choosing a rubber material.
1. Flexible
Many rubbers have great elongation properties, which allow them to withstand loads with a low risk of deformation. A general rule is that as the hardness of a rubber material lowers, its maximum elongation will also improve. Although this is not true 100% of the time, lower hardness rubbers tend to be very flexible and can recover easily from compression.
2. Temperature Resistant
Certain rubber materials can operate within very large temperature ranges, like silicon rubber, which can withstand temperatures as low as -70°C. Fluoro rubber can operate as high as 230°C. On top of these great operating temperatures, most rubbers also have excellent water resistance properties, which helps them thrive in humid environments.
3. Noise and Vibration Dampening
Rubber materials are commonly used as a cushioning material due to its good elongation and shock absorption properties. Vibration dampening and flexibility go hand in hand, as a more flexible rubber can absorb shock and reshape itself quickly.
In cases where extreme shock absorption is necessary, low elasticity rubbers can have elongation percentages up to two times of a standard rubber.
4. Cost-Effective
Rubber materials are typically less expensive than other materials. However, parts made from rubber may not be as durable as other metals or polymers, so replacement is needed more often. If your system is dealing with low compression loads, a rubber product could be used as a great option to reduce costs.
Comparison of Rubber Material Types
There are many different types of rubber that may be better suited for certain applications over others due to their unique properties. This section will help narrow down which rubber could be best suited for your application by going over strengths and weaknesses of each type.
| Rubber Material Type | Benefits |
| Nitrile Rubber (NBR) | Abrasion and Oil Resistant Low Cost |
| Chloroprene Rubber (CR) | Well-Balanced Properties High Mechanical Strength |
| Ethylene (EPDM Synthetic Rubber) | Weather Resistant Low Cost |
| Butyl (IIR) | Weather Resistant |
| Fluorine/ Fluororubber (FPM) | Excels in Most Properties |
| Silicon Rubber (SI) | High Heat Resistant |
| Low Elasticity Rubber (Hanenaito®) | Shock Absorbent Vibration Absorbent Oil Resistant |
Nitrile Rubber (NBR)
Nitrile rubber, often shortened to NBR, is one of the most used types of rubber across many different industries. Despite being one of the most economical options of rubbers, it still offers excellent abrasion resistance and oil resistance.
The mechanical strength of NBR is on par with many other more expensive rubbers, making it a great option to use in many different applications. Its main drawback is its poor temperature resistance qualities and below-average chemical resistance.
Chloroprene Rubber (CR)
Chloroprene rubber has very well-balanced properties with no true weaknesses. Its mechanical strength is of the highest quality, beating out all other available rubbers in allowable tensile strength.
If your application calls for a high strength rubber, chloroprene is a great economical choice. Outside of its mechanical strength and being a jack of all trades, chloroprene rubber’s biggest downside is that it does not truly excel at anything else. It has very average weather resistance, abrasion resistance, and oil resistance.
Ethylene (EPDM Synthetic Rubber)
Ethylene, also known as EPDM, is one of the best options when looking for a rubber with excellent weather resistance properties. It has great resistance to water and can be used in both cold and warm temperatures.
Ethylene is a great option if your system needs to operate in harsher weather conditions while keeping overall costs low. EDPM’s weaknesses are its poor oil resistance and fire resistance properties.
Butyl (IIR)
Butyl rubber excels in sealing applications due to its airtightness. Due to this and its great weather resistance properties, Butyl is commonly used for the inner tube of an air tire. Butyl should not be used in applications where it can be exposed to oil, as its oil resistance properties are inferior to most other rubbers.
Fluorine/Fluoro Rubber
Fluorine, or Fluoro rubber, is a rubber that stands out among its competitors due to its performance in many different properties. Compared to the rest of the rubbers on this list, it performs the best in weather resistance, abrasion resistance, heat resistance, and oil resistance, while also having great mechanical strength on top of that.
While it does not have any major weaknesses, it is among one of the most expensive types of rubber offered. If price isn’t an issue, Fluorine will perform exceptionally well in most applications.
Silicon Rubber (SI)
Silicon rubber offers excellent temperature resistance when used. As mentioned earlier, the allowable temperature ranges all the way from -70°C up to 200°C, allowing for a total 270°C range that Silicon rubber can excel in.
One downside is its mechanical strength and abrasion resistance properties, performing the worst out of the mentioned rubbers. If you are operating under extreme temperatures, Silicon rubber would be a great choice if you are not using it for heavy load bearing applications.
Low Elasticity Rubber (Hanenaito®)
Hanenaito® is a type of low elasticity rubber that is used for its stellar shock absorption properties. Low elasticity rubber is used mostly as a cushioning material since it has excellent vibration absorption properties.
During shock absorption tests, we found low elasticity rubber can fully absorb the load more than three times faster than standard natural rubber. Although Hanenaito® is great in shock absorbing applications, it does fall short with its heat resistance and lower temperature resistance.
Rubber Materials Compared to Polyurethane
Rubber materials have excellent shock absorption properties, and due to their flexibility they can be used over polyurethane as long as loads aren’t high.
Rubber materials do not have as high tensile strength as polyurethane, but their great elongation properties can make up for lower strength if the shock or vibration that is being absorbed is a lower strength or widely distributed load. The flexibility of rubber allows for a much lower impact acceleration and convergence time in test cases.
If your application does not need to withstand high forces as polyurethane material would, rubber material would likely be a great alternative due to its cost-effectiveness. Rubbers like chloroprene and NBR still have good mechanical strength while often being a less expensive option.
Rubbers also perform better than polyurethane under high heat and in chemical applications. As stated earlier, certain rubbers can withstand temperatures as low as -70°C to as high as 230°C. The temperature ranges for polyurethane are only from about -20°C to 120°C. Many rubbers also have excellent chemical resistance and water resistance, while the chemically resistant properties of polyurethane are generally rated as not acceptable.
As it was alluded to throughout this reading, polyurethane should still be used over rubber if your shock-absorbing application needs to withstand high loads. The tensile strength of polyurethane can range anywhere from 2-4x higher than rubber, making them a much better choice if needed to absorb or help dampen stronger or faster moving forces.
Although rubber can still be used across different industries in many unique ways, the high strength and durability of polyurethane allows it to be a slightly more versatile material that can excel in multiple different kinds of applications.
| Polyurethane | Rubber | |
| Advantages | Durable Oil Resistant Higher Load Capacity Heat Resistant | Flexible Chemical Resistant Cost-Effective Biodegradable |
| Disadvantages | More Costly Less Flexible | Less Durable Lower Load Capacity |
Configurable Bolts, Pushers, and Stoppers
MISUMI offers a wide range of bolts, pushers, and stoppers with different material options.
