April 10, 2019 | Case Studies

The Right Material Keeps Coal Miners Safer

The Customer

The customer is a leading global provider of products and services that increase safety for the mining and energy sector across a variety of environments. One of their specialties is advanced safety products that monitor proximity in both underground and above ground mining environments.

In this case, the product was an armor housing for a proximity detection system for underground mining, which would sound audible and visual alarms if a worker came within a certain range of equipment. The goal of this product is to reduce the instance of crushing or pinning type accidents in underground environments.

The Challenge

The customer came to Cope Plastics looking for assistance in material selection for the armor housing that covered the electromagnetic sensor in this proximity system. There were several requirements this material needed to satisfy in order to work for the customer.

First, the armor housing needed to be strong enough to withstand rock falls, which are a chief concern in mining environments. The strength of this component was even more crucial because it served a key function in a safety system that could save coal miners’ lives.

They also needed a material that could stand up to the harsh chemicals of the mining environment in addition to one that would machine to the tolerances needed for the application.  The part was 4 inches thick, so material availability was a small challenge. Finally, the housing’s design was very intricate and required special equipment to machine the part per its design.

The Solution

The Cope Plastics design assistance team worked with the Cope rep and customer to test several solutions to satisfy the requirements of the part. After testing with several materials, they identified acetal as the ideal solution.

Acetal is durable and proved able to resist rock falls, in addition to being highly machinable. We were able to not only recommend acetal as the material for the project, but also because of our experience and equipment capabilities, we were able to provide the customer with the finished part.

Our team understood the importance of accomplishing the goals of our customer—keeping coal miners safe and even saving lives.


We tested many different materials when determining the best method to manufacture this part. Our team understood the importance of accomplishing the goals of our customer—keeping coal miners safe and even saving lives. They approached this project with passion and determination to continue testing and prototyping until they found the perfect material that would help accomplish exactly that.

According to the customer, this armor housing has not had a single failure in the field. In fact, this product has been so successful that it is one of the preferred systems of MSHA, which is the United States Mine Safety and Health Administration.

Our customer continues to expand their market reach both domestically and internationally. Also, because of the success of the acetal material in this case, more metal parts have been converted to plastic in this application—improving safety and efficiency across the customer’s entire industry.

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