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Plastic Molded Bearings vs. Powdered Metal Bushings


Engineers are turning to molded plastic bushing and bearings as a replacement for powdered and sintered metal wear components.  In this article, we are going to take a look at four specific reasons why.

Other articles on advanced polymer bearings and bushing:


1. Reason #1 Outstanding Mechanical Properties

When compared to metal bushings and thrust washers, polymers have low to no maintenance and with some polymers improved dimensional stability.  Polymer bearings typically provide a tighter, more space efficient fit and weight much less.  They are relatively easy to install.   Another positive aspect of plastic wear components is the fact that they can provide more effective heat transfer, thus preventing an unnecessary build-up of heat.

Polymers are low-friction materials to begin with, and many plastic components are self-lubricating.  This can eliminate the need for grease or other lubricants.  Another plus for polymers is that there are no requirements or special requests needed when it comes to the mating material.


2. Reason #2 Improvement Through Composites

There are a variety of additives and reinforcement materials that can be added to a plastic bushing to improve its mechanical properties (such as strength and impact resistance) and increase its self-lubrication. 


3. Reason #3 Homogenous Structure

This leads to another important difference when it comes specifically to injection molded plastic bearings and bushings:  because the reinforcing fibers and additives are combined prior to injection molding, the resulting bearing has a homogenous structure.  As the bearing starts to wear, there is no change in performance due to a new layer of material now being exposed.  This was a problem with composite bearings in the past, where the exterior layer would wear away and leave exposed a layer with a higher coefficient of friction, leading to catastrophic failure.


4. Reason #4 Large Variety of Environments and Applications

Another benefit of utilizing plastic materials for wear applications is the variety of products available suitable for your specific application, such as high strength, FDA compatable, high performance, anti-static, chemical resistence and low frction.  They are used in everything from copier machines and exercise equipment to food processors and industrial equipment.


As a replacement for powdered metal bushings and thrust washers, molded plastic has proven to be more cost effective and more reliable, as downtime for repairs and replacement of bushings is reduced.  The result is equipment that is safer and more environmentally friendly because of the reliability of plastic wear products. 

For more in-depth information on the process of bearing selection in engineering design get a free copy of the Advanced EMC Technologies, “7 Step Process in Bearing Selection.”



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