Aerospace & Defense

Plastic Injection Molding for Aerospace & Military/Defense Industries

Aerospace Plastic Injection MolderPlastics and composite materials are critical to modern component design for airplanes and defense products. They combine light weight with high strength and temperature resistance for structural components, electrical products and optical applications.

Parts can be highly engineered to meet demanding requirements, and careful quality control is needed to ensure consistent product. Typical tolerances are +/- 0.00025” (0.0064mm), confirmed using either measuring microscopes or fully automated (CMM) Coordinate Measuring Machines.

In general, molding is not optimized for high-volume production, but carefully-controlled to reduce stress that would affect characteristics of the finished piece.

Materials & Processes

Most applications involve engineered resins and complex mold cavities. Careful control of the molding process, including gate design, temperature and pressure, is necessary to yield quality parts.

Additionally, many parts require multiple post-processing steps, including drilling, machining, plating and fabrication. Plastic Molded Concepts provides these services under one roof to maintain consistent management control – ‘One throat to choke.’ This helps reduced the cost of purchasing.

Plastic Molded Concepts is frequently the ‘Go To’ molder to complete the job after another molder has tried and failed to deliver parts. Our experience with complex projects, and our tight relationship with multiple resin suppliers gives us the knowledge base to get it done right.

Special Considerations

Engineered resins and complex part design require a molder to go far beyond standard operations. It is important to consider the physics of the molding process, and the chemistry of what happens to resins at elevated temperatures.

Plastic Molded Concepts was an early champion of in-mold monitoring of shot pressure. By studying the behavior of viscous fluids (rheology), we can optimize the molding process for every cycle. (Insight: molding is not ‘set and forget.’ There are many reasons why resins will NOT behave the same way from one shot to the next).

Just as important, some resins are sensitive to temperature and pressure. Even if barrel temperatures are held to a minimum, sensitive compounds can undergo degradation if frictional gate dynamics are not monitored.

Finally, many defense contracts require US manufacture, with tight access controls, a disaster recovery plan and compliance with ITAR regulations. Our centrally-located Eagle, Wisconsin, facility meets all these requirements.

How to Get the Best Results

Many aerospace and defense contractors partner with a molder early in the design/engineering process. They find this the best way to get the product characteristics they need in a finished system. Sometimes this involves adjusting part design assistance based on molding physics, in order to minimize stresses and resin failures. The molder will suggest changes in draft angle and gate placement to distribute resin evenly in the cavity.

Molders may also address dimensional stability (Insight: some resins show dimensional changes long after molding – these changes are predictable and critical to understanding how to make parts with critical size requirements).

At the same time, program specifications are subject to change, and molders must be able to respond quickly to change orders. Even contractors that typically work with foreign suppliers find that they get better results by ‘Onshoring’ molding operations.

A centrally-located US manufacturer can reduce time-to-market and turn a project into a revenue-generator quickly.