Rubber Isolator Mounts: Choosing the Right Materials for Your Vibration Damping Solution
Specifying specs for rubber isolator mounts isn’t just a matter of picking a shape and a size. The polymer behind the part determines how much vibration damping it actually delivers, how long it holds up under repeated flexing, and whether it survives the environment it’s installed in. Two isolators can look identical on a drawing and perform completely differently if one of them is molded from the wrong compound. Material selection is what separates a rubber isolator mount that lasts from one that hardens, cracks, or loses its damping performance long before the equipment around it wears out.
Selecting the Right Vibration Damping Material for Your Rubber Isolator Mounts
Not every flexible rubber compound performs the same way under sustained flexing, and material choice drives how well a rubber vibration isolator manages damping over its service life.
Natural rubber offers excellent resilience and low heat build-up under repeated flexing, making it a strong choice for rubber isolators subjected to constant, moderate-frequency vibration.
Neoprene (CR) adds resistance to oil, weather, and moderate temperature swings, a common requirement for isolators mounted outdoors or near hydraulic systems.
Silicone holds its flexibility across a wider temperature range than most general-purpose compounds, which matters for rubber vibration isolator mounts operating in extreme heat or cold.
Beyond base polymer, durometer (hardness) and compound formulation determine how much deflection an isolator allows before it becomes rigid, which directly affects how much vibration damping the mount delivers. This is a compound-by-compound engineering decision, not a one-size-fits-all spec, and it’s one reason off-the-shelf rubber isolator mounts don’t always hold up once load, temperature, or chemical exposure moves outside general-purpose territory.
Matching the Material to the Industry
The right compound for a rubber isolator mount depends as much on where it’s installed as what it’s damping. A few examples of how material selection tracks with the industries Moldtech serves:
| Industry | Common Material Considerations | Why It Matters |
| Aerospace | Silicone and specialty compounds rated for temperature extremes and weight constraints | Isolators need to maintain damping performance without adding unnecessary mass |
| Military | Neoprene and other weather- and chemical-resistant compounds | Equipment is exposed to harsh, uncontrolled outdoor environments |
| Industrial | Natural rubber and general-purpose elastomers | Pumps and machinery run continuous, moderate-frequency vibration cycles |
| Medical | Silicone and other biocompatible compounds | Devices require precise, low-durometer isolators in tight installation spaces |
| Infrastructure and Construction | Neoprene and durable general-purpose compounds | Mounts are exposed to weather, moisture, and sustained structural loads |
| Electronics | Low-durometer silicone or foam compounds | Small, sensitive assemblies need isolation from shock without added bulk |
This isn’t an exhaustive list of every application Moldtech supports, but it illustrates why “rubber isolator” isn’t a single spec. The compound must match the environment the mount will actually see in service.
Why Custom Material Selection Beats a Generic Isolator
A standard, off-the-shelf rubber isolator mount is formulated for average conditions and average loads. Once an application calls for a specific temperature range, chemical exposure, load capacity, or installation footprint, a generic compound is guessing rather than engineering. Custom material selection lets an isolator’s durometer, polymer, and molding process all be built around the actual vibration frequency and operating environment it will face, which is what keeps a rubber isolator mount performing at spec instead of degrading ahead of schedule.
If you’re specifying rubber isolator mounts, vibration isolators, or other custom molded rubber components, contact Moldtech’s engineering team for a quote, or visit the Dampers and Isolators product page to review Moldtech’s full capabilities.
FAQ’s
What material is best for a rubber isolator mount?
It depends on the application. Natural rubber suits constant, moderate-frequency vibration with low heat build-up. Neoprene adds resistance to oil, weather, and moderate temperature swings. Silicone holds flexibility across a wider temperature range for extreme heat or cold.
Does durometer affect how well a rubber vibration isolator performs?
Yes. Durometer, or hardness, determines how much an isolator can deflect before it becomes rigid, which directly affects how much vibration damping the mount delivers under load.
Can Moldtech match a rubber isolator's material to a specific industry or environment?
Yes. Moldtech engineers custom rubber isolator mounts around the load, frequency, and environmental demands of the application, using thermoset injection molding, compression and transfer molding, overmolding, sponge/foam molding, and LSR/HCR silicone molding.