Custom Aerospace Injection Molding For the Defense Industry

The aerospace industry requires the use of high-performance materials and accurate fabrication. The engineering thermoplastics specialty of Prolean Tech provides dependable solutions, and effective injection molding quality control to these challenges. In molding aerospace products it’s paramount to achieve accurate functional features and uniformity in parts. However, injection molding offers freedom in design, a vast array of materials to use, and is inexpensive to manufacture, still, inaccuracies are there. Usually, it’s applied in the production of aerospace parts such as panels, housings, and ducting to meet the required standards of aerospace engineering. The injection molding process involves heating the polymer material and then injecting it into metal molds to create intricate shapes with close-dimensional control. Prolean Tech specializes in providing these high-quality flight-ready components on time and to the most stringent standards. 

Why Use Injection Molding for Aerospace Industry?

Aerospace injection molding

Injection molding is a typical process in the aerospace industry for producing plastic parts. Here are some reasons engineers prefer it in this demanding industry. 

Design Flexibility 

The aerospace plastic injection molding is highly suitable for design flexibility. Molds are easily and cheaply made by using rapid tooling techniques such as 3D printing. Ideas can be altered during the manufacturing process without much time wasted by the engineers. 

Material Selection 

Aerospace injection molding accommodates a wide range of materials ranging from simple thermoplastic materials to complex composite materials. This makes it possible for engineers to choose the materials they require for strength, thermal conductivity, and the ability of the material to last longer. 

Tight Tolerance and Precision 

The rapid injection molding process provides the parts with dimensional accuracy and allows for achieving tolerances of +/-0.001’’. The parts often require little further processing after the fabrication stage thus making it economical. 

High Strength 

Aerospace parts or products are subjected to extremely tough conditions as in-flight loads and vibrations. The injection molding process also guarantees that these parts possess the requisite mechanical and thermal properties that will enable them to perform effectively in those conditions. 

Lightweight 

Weight is a critical factor in aeronautics. Compared to metals, injection molded plastics are lighter in weight and possess greater strength which means increased fuel efficiency and performance. 

Consistent Quality 

Injection molding processes make it possible to achieve high reliability and create identical parts, multiple thousands of times. This makes it a perfect choice especially when it comes to large production runs as the quality is likely to be well maintained. 

Custom Finishing 

There are many available choices of injection molding finishes ranging from matte to glossy with surface roughness as low as 0.012µm. Manufacturers can also offer different textures on the products in the form of aesthetic or even functional value. 

Low Cost 

Compared to other molding techniques such as die casting or even machining, injection molding is relatively affordable. Molds are cheaper to make while the use of plastic makes it economical to transport and store since it is relatively lighter than metal.

Major Cost Drivers In Aerospace Injection Molding

Let’s figure out some major factors affecting the costs of aerospace injection molding;

Limited Flexibility 

Nonetheless, the injection molding process is not very flexible, which is one of the biggest drawbacks of the method. Molds changeovers, make the process costly, and steep. Although steel molds are a reasonable option for small production; however, their durability is lower. 

Material Constraints 

Tooling is normally designed for a certain material and therefore changing the material would call for a new tool. As has been postulated, the aerospace industry is highly governed, and it involves processes such as testing; thus, changing materials involves additional costs and time. 

High Tooling Costs 

Injection molds are expensive, especially for small runs and this may prove costly when used in making molds. However, if we use aluminum tooling it will be inexpensive and can last up to 20000 parts and for steel tooling, it will be up to 50000 parts. In such circumstances, the conventional techniques of structure construction could be costly and hence other techniques like 3D printing might be the most suitable. 

Aerospace Injection Molding Materials and Components

High-performance polymers including PP, HDPE, and PEEK are utilized in aerospace injection molding to produce various parts including bezels, turbine blades, and chassis parts.

Injection Molding Processes for Aerospace Applications

Injection molding has several techniques that are unique to aerospace engineering as follows. 

Plastic Injection Molding 

This standard process involves the placing of the mold cavity in which the molten plastic is injected to create the intended part. Another benefit of the mold is that it takes into account shrinkage and draft angles thus making the production very precise and accurate especially when producing large quantities. 

 Overmolding 

Overmolding is a process, where two different materials are bonded together to create a single component. It is used to describe a component, created from two different materials. The first part of the mold is made during the first part and the second part of the mold, the second component or the overmold is then made. The over-molding is optimal for such parts as aerospace latches where the core of the part has to be strong while the outer surface is comparatively soft. 

Insert Molding 

Insert molding uses metal and plastic material needs to be placed in the mold to make plastic parts. It entails putting a metal core then the molten plastic is injected around the core to make a part of high mechanical strength. In particular, it is used when it concerns electrical components of aerospace systems. 

Micro Molding 

Micro molding is used in a situation where components are very small and in some instances, the part weighs less than 0.1 gram. Even these components though small in size have high levels of accuracy and thus are applied widely in aerospace parts such as micro gears, sensors, and bearings. 

Gas-Assisted Injection Molding 

When using gas-assisted injection molding, the nitrogen gas is injected into the mold cavity after the plastic. It helps in reducing the amount of material to be used and at the same time reduces problems like warpage and shrinkage. In aerospace, it assists in the formation of high-density and thin-walled structures which are vital to sustain the aerodynamic feature of the plane. 

Co-Injection Molding 

The technique enables aerospace engineers to bond two or more materials with dissimilar properties such as the hardcore and soft skin. It is particularly effective in enhancing the mechanical properties of parts and at the same time reducing the cost. 

Micro-Injection Molding 

Micro injection molding is used to create small-sized aerospace parts with sizes in the micrometers range. This is important in aerospace to produce small parts including sensors and micro-electronic connectors because precision and strength are critical. 

Liquid Silicone Rubber Molding 

LSR molding injects and cures silicone to create a part that has very good thermal stability, flexibility, and strength. In aerospace, LSR is used in all the areas where the seals, gaskets, or any other parts are needed to be able to withstand both high and low temperatures and sealing. 

(Read about our guide to automotive injection molding for custom auto-cars, and vehicles)

Key Aerospace Products Made Using Injection Molding

Injection molding proves useful for the creation of mandatory aerospace parts due to its accuracy as well as versatility in the choice of materials. 

Battery Housings 

Battery housing design

Battery casings in aircraft are made of injection mold which holds electrical parts and fluid. These are robust to shield other delicate parts of the battery from in-flight vibrations. Further, more chemical-resistant plastics are applied to avoid corrosion by battery fluids. 

Circuit Enclosures 

Circuit enclosures

These enclosures protect electronic circuits in aircraft while at the same time protecting them from vibration. The electrical insulation of the plastic makes it possible to shield the internal circuitry from electrical interference during flight. 

 Radomes 

Aircraft radomes

In simplest terms, radomes are used to shield communication devices from the outside environment as well as from electrical interferences. Fluoropolymers are one of the types of thermoplastics, which are used due to their high durability and resistance to weather conditions. 

Pitot Tubes 

Airplane pitot tube

Pitot tubes are used to measure airflow for pilots and their surface should be smooth so that they can work properly. With injection molding, it is possible to achieve accurate part shapes using materials that will not crack under cold conditions and high altitudes. 

Turbine Blades 

Small windmill

In small aircraft and drones, plastic turbine blades are used so that they don’t add much weight to the aircraft. Injection molding provides the strength and the smooth surface, needed for effective propelling. 

Chassis Parts 

Some of the plastic chassis parts are the ones used in drones and small aircraft industries. All of these components are most suitable to be made by injection molding because this process is favorable in the mass production of strong and smooth-surfaced parts at a low cost. 

Bezels 

Bezels are applied to seal aircraft windows and in this process, the gaps have to be made airtight to prevent the penetration of air. Plastics are suitable for these components because the part is lightweight and not load-bearing and the material is easily formed and creates a good seal.

The Future of Injection Molding in Aerospace and Defense

The aerospace and defense sectors are experiencing innovation in injection molding.

Innovative Hybrid Manufacturing  

The integration of additive manufacturing and conventional mold making is enhancing the quality of injection molding. This hybrid approach forms complicated mold inserts which improve the cooling and increase the productivity. 

Advanced Lightweight Materials  

New types of composite materials such as thermoplastic composites and polymers reinforced with nanomaterials are being used more frequently. They offer aerospace components with enhanced mechanical properties though offering less mass. 

Automation and Smart Systems 

Current trends in the industry are being made possible by the integration of AI and IoT that automates injection molding processes. These systems learn and improve the manufacturing parameters to better utilization of resources and quality of products. 

Sustainable Material Solutions 

Biopolymers and post-consumer recycled polymers are being adopted in substitution to hazardous polymers, to minimize the environmental footprint in aerospace products manufacturing. 

Design Optimization with the Help of Simulation Software 

Design for manufacturing (DFM) software enables engineers to optimize parts at the initial stages of the design process. This makes certain that there is the best kind of performance and efficiency in the injection molding process in aerospace applications.

Injection Molding of Custom Aerospace Prototypes and Parts by ProleanTech

Prolean Tech provides overmolding, insert molding, and premium injection molding services for aircraft components, and the defense industry. Prolean has a competent and committed staff and advanced technology to guarantee both prototyping and production at a very fast rate. 

Our online quoting system is fast. So, upload your design, receive your quote, and a thorough Design for Manufacturing (DFM) report. Moreover, we ensure efficient service delivery as well as providing quality support during the process.

Summing Up

The purpose of this article is to bring out the major advantages of aerospace injection molding as well as the steps involved in the process. The manufacturing method allows for designs to be changed freely, weightless parts, and compatibility with high-performance materials, which is why the aerospace industry is an appropriate one for this method. Prolean Tech also offers professional services to improve production efficiency, decrease expenses, and satisfy the strict demands of aerospace projects. We have the capability of supporting you in achieving the precision, durability, and efficiency in your aerospace manufacturing requirements. For more information and specific services, please contact ProleanTech.