PEEK Plastic Injection Molding Military/Aerospace Case Study

Self-Destruction in Military/Aerospace Part Solved

Here at Plastic Molded Concepts, customers turn to us for solutions to complex plastic molding failures.

This particular customer had a unique and complex PEEK plastic injection molding issue that its previous supplier was unable to solve: product self-destruction.

Find out below how Plastic Molded Concepts solved and corrected this critical product failure issue in a military/aerospace component that was using PEEK plastic injection molding.


A military and aerospace hardware manufacturing company came to Plastic Molded Concepts with a product failure issue that persisted with their existing plastic injection manufacturer.

The company called us and explained that their product was self-destructing within months of being received from the molding processor.

They told us that when they opened the parts on the assembly line to add them to the assembly what was supposed to be one part had deconstructed into many parts, resulting in a defective and unusable part.

After asking a series of technical troubleshooting questions, the company requested we visit the plant for an in-depth review and analysis of the molding process and tooling in place at their present supplier.

What Went Wrong: Molding Process

When we arrived on-site we immediately identified that one of the major sources of failure was caused by an improper PEEK plastic injection molding process.

The supplier the company was using was a high volume molding house and had not developed the process correctly. The molding house was not experienced in dealing with complex engineering-grade resins. The supplier did not realize they needed to process the resin, 50% carbon-filled PEEK (Polyetheretherketone), according to the exact requirements laid out in the resin manufacturer’s manual.

The molder was processing the resin cold, not realizing that the mold temperature had to be 360 degrees. This meant part properties could not be attained, which is why the product was self-destructing within months.

What Went Wrong: Tooling Equipment & Process

During our analysis, we also found that a deformation was occurring specifically in the direction of an out-of-tolerance condition. When we reviewed the tooling equipment and process it was apparent that the product could never maintain its specified dimensions because of an absence of underlying structural support in the mold.

We also knew the part production required very high pressures and the molding machine would have to have a transducer in order to control actual cavity pressure of the resin.

When we reviewed the tooling, we identified that the molding machine being used did not have a transducer installed and closed looped with the mold. This made it unable to effectively and consistently control the amount of plastic pressure being injected into the mold.

The absence of consistent and accurate pressure control meant every part was being produced to a different measurement, contributing to a variety of out-of-tolerance conditions.

Since the machine could not consistently control the molding process to tight enough tolerances and could not maintain a reliable consistent cavity pressure, a steady state condition could not be established.

Furthermore, as these out-of-tolerance conditions began at the molding process and the parts were moved to the final stages of machining additional out-of-tolerance conditions would appear.

Our Findings

We provided extensive documentation to the customer that detailed our findings and recommendations. We explained that the result of our findings meant that nearly half of all parts this supplier produced were defective.

We also explained that a commodity molder who specializes in the shoot-and-ship molding process was not suitable for the kind of parts they needed produced and the engineering resin that was required for production.

After meeting with the customer to explain our findings and recommendations, they determined it was critical to transfer part production away from their current supplier.

Since the customer already trusted our expertise and now understood our capabilities & how our equipment was different than their current supplier, they chose to immediately transfer part production to us.

The Solution

First, we installed support pillars to improve underling structural support in the mold, as well as a transducer to eradicate parts being produced out of tolerance.

Next, we began by processing the resin to exact manufacturer specifications to eliminate part self-destruction, as well as consistent dimensional results.

Finally, we provided the necessary machining and CMM checks to ensure every single part was produced to exact dimensions.

The Follow-Up

The customer was grateful for the industry knowledge we provided them. They told us it was immensely helpful to have all that information moving forward, so they can try to troubleshoot issues that could arise down the road with other vendors.

Since this project, the customer has worked with us on 15 other projects, as well as consulted us for research and product development needs.

Why Customers Choose Plastic Molding Concepts

In an industry saturated with commodity molding, it’s incredibly difficult to find a qualified domestic plastic molder who specializes in complex molding and engineering-grade resins.

Plastic Molded Concepts is one of very few molding companies in the entire world who has the expertise and capabilities to handle technical, high level molding projects. Get a quote today!

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