Moldtech Inc.'s Custom Application Improves Isolator Protection

Lancaster, NY – Moldtech Inc. was asked to manufacture an isolator that would stand up to continual drenching in diesel-fuel-based cutting fluid and would not experience any degradation in isolation performance or fatigue life.

The traditional isolator manufacturing process bonds natural rubber to metal mounting plates; natural rubber provides optimum isolation ability and excellent fatigue life. The client's isolator had a chemical resistant coating, but constant immersion in the highly-volatile environment under extreme load conditions often compromised the coating layer and led to almost immediate failure of the mount. Replacing a failed mount in the field under such challenging conditions is expensive and time consuming.

Moldtech began by enveloping the isolator in a boot manufactured with HNBR (hydrogenated nitrile butadiene rubber), an approach that had been tried unsuccessfully in the past by others. Initial Moldtech trials showed that the HNBR was unable to withstand the high load and strain present at the surface of the part, so Moldtech chose to alter the physical configuration of the boot. By convoluting (i.e. creating a wavelike pattern) the rubber boot and wrapping it around the isolator's metal plates with a high performance bond and mechanical interlock, the isolator became completely separated from the aggressive environment. The convolutes are designed to "unfurl" but not stretch, as the mount moves through its complete range of motion, which virtually eliminates the failure-inducing strains and allows the HNBR boot to endure as long as the natural rubber isolator.

Although this particular application didn't require heat resistance, the high temperature capabilities of HNBR increase the service temperature of the natural rubber and are an effective barrier. Further resistance to radiant heat can be provided by applying Moldtech's proven reflective coating to the HNBR.

"The unique combination and design," says Rob Paladichuk, Moldtech VP of engineering and operations, "delivers all of the isolation and durability requirements of natural rubber, with the added protection from the HNBR against degradation from fuel and oil. This is another example," he adds, "of our ability to engineer out-of-the-box solutions for our customers, and we are particularly proud of the fact that we were able to successfully iterate on a ‘we already tried that' idea."

After five months in the field under real world conditions, Moldtech's boot isolator remained completely sealed; the isolator showed no evidence of wear or exposure to the cutting fluid. The HNBR boot and isolator combination has applications for companies requiring a high performance (both optimal isolation and strength), chemical resistant option for anti-vibration isolators and dampers, including those in high temperature, harsh environment applications.

About Moldtech Rubber, Inc.

MOLDTECH™ – expert design engineering and manufacturing of custom molded rubber parts to maximize cost savings and assure superior part performance. Moldtech utilizes a full line of elastomers in its custom production of a wide variety of molded rubber products. For more information, visit or contact the company at 716-685-3344 or

Moldtech Inc.

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