Replacing Metal Parts with Plastic Yields Better Field Performance

Engineering plastics are a great alternative to metal parts in a wide range of applications. They aren’t subject to corrosion, they make for lighter, quieter operation, and they can prolong the life of mating parts. What sets engineering plastics apart is that their chemical composition allows them to withstand tougher environments and more demanding applications than traditional consumer plastics. Depending on the material, engineering plastics may offer lower coefficients of friction, greater thermal resistance, and higher PV ratings, among other features. 

The Customer

Cope’s engineering plastics team was visiting one of our large OEM customers who specializes in construction equipment used for asphalt paving. They were conducting an educational seminar for the customer’s team of engineers, showing off the capabilities of Cope’s specialized plastics.

The Challenge

A thrust washer (also referred to as a thrust bearing or thrust plate), is a round component that sits between parts on a shaft and permits rotation of the parts. They are designed to support predominantly axial loads. Traditionally, thrust washers have been made of metals such as bronze. 

The customer had been using steel thrust washers in their equipment that were causing binding issues and hindering performance. The gear on their shaft was coming in contact with other metal components on the shaft, preventing it from rotating freely. As we were discussing different available plastics and showing some of the parts we had fabricated, the engineers in the room got curious about whether an engineering plastic would resolve the issues they were having with their thrust washers.

The Solution

Our team spent time talking with the customer’s engineers to determine the requirements of their application: continuous use temperature, compressive strength, and wear resistance. They also learned about the types of environments where the trust washers would need to function: asphalt paving can be a dirty job. After analyzing the customer’s application, the Cope team determined that NylatronⓇ GSM Blue (a type of Nylon 6) was the ideal material for the job. 

NylatronⓇ GSM Blue offers the same strength in load capacity as NylatronⓇ GSM PA6, but with improved frictional characteristics. It is ideal for lower speed, high-pressure applications, making it a perfect fit for the customer’s application.

The Result

The customer provided drawings to our team to help guide the prototyping process. We fabricated a small run of the parts using NylatronⓇ GSM Blue and the customer began testing the parts in the field. During testing, the shaft was able to move freely and the plastic thrust washers were not causing any premature wear on other parts they were interacting with on the shaft. The customer also reported no noticeable wear on the plastic thrust washers themselves.

After successful testing, the customer decided to switch from steel to NylatronⓇ GSM Blue plastic for its thrust washers in the paving equipment they were manufacturing. Cope’s solution continues to work well in the field and has eliminated the problems the steel thrust washers had been causing before making the change.