"It's not rocket science." When people say this, they are indirectly acknowledging how intensely complicated aerospace engineering is when compared to most mundane things. Flight requires a complex balance of innumerable factors far more complex than worth listing here.
Polymeric microspheres are not rocket science, but they are used in rocket science. These microspheres are ultra–lightweight fillers made from a flexible polymer shell. They are commonly added to materials, improving their physical properties and enhancing overall performance.
We often see polymers added to silicone, sealants, clay, and composite materials. Now, we look at their implementation in aircraft design. Let's review a few ways microspheres have helped the aerospace industry.
Lightweight Aircraft Coatings and Paints
Microspheres primarily help as material additives to lower the overall weight of a substance. Looking at paint, microspheres occupy a controllable amount of space in the mixture; and being a lower weight, they create a lighter final product at the same volume. In aviation, Dualite microspheres are used in two specific paint-based applications.
Aircraft require visible exterior marking. One such case is to indicate the aircraft registration number. This is essential information required by regulatory authorities (like the FAA or EASA) to monitor the comings and goings of aircraft. This paint must be bold enough to be seen at a distance. Ideally, they do so without adding much weight.
Keeping the aircraft weight as low as possible helps save fuel and reduces required engine torque; the latter mitigates one common source of component failure and costly repairs. Lightweight microsphere additives help ensure the paint is as light as possible without sacrificing any of its cosmetic properties, ensuring it is visible, spreads evenly, and lasts against harsh weather conditions.
We also see microspheres used in the coatings that line fuel tanks. Fuel can put a lot of chemical strain on unprotected substrates. To ensure the inner linings of fuel tanks stay in good condition, protective coatings are applied to the inner chamber. These coatings would be heavy if not for the inclusion of microspheres in their formulation. Microspheres are unique as they can withstand exposure to the harsh chemicals found in fuel. This makes them irreplaceable as weight and cost savers.
Improving the Properties of Aircraft Sealants and Composites
In addition to the weight savings previously mentioned, sealants and composites enjoy unique benefits from added microspheres.
Microspheres for Composite Materials
The composite manufacturing process is involved; some essential considerations include their long exotherms and surface roll-out times. In post-production part fabrication, machinability issues can occur from either the cracking of brittle parts or due to constant blade wear. Polymeric microspheres address these issues along with addressing other integral factors.
In terms of material overhead, polyester resins can be quite costly. By comparison, microspheres have a far lower gallon cost. By substituting resins for polymeric microspheres, you save on material expenses. Microspheres are also good insulation, which allows them to reduce exotherm and increase production cycle times.
Additionally, being hollow yet sturdy plastic spheres, they take impact well, improving the durability of the material. They also offer great structural support as they take screw holds well due to their flexible nature.
To summarize, composite metals have greater impact tolerance, more manageable exotherms, and improved production variables. They are also cheaper to produce and lighter as a final product.
Microspheres for Aerospace Sealants
For all the properties listed above, especially the benefits for weight and thermal management, microspheres offer unique advantages when incorporated into aircraft-grade sealants.
The use of polymeric microspheres allows formulators to customize the properties of sealants as to meet specific requirements. By selecting microspheres with specific characteristics (such as size, shape, or material composition), the performance of the sealant can be tailored to the intended application. One example of this is their influence on the rheological properties of the sealant, providing control over its flow and sag resistance. This is particularly important in vertical or overhead applications where the sealant needs to stay in place during curing.
Microspheres also improve the overall durability and toughness of the sealant. This is important in applications where the sealant is exposed to environmental stressors, such as temperature fluctuations, moisture, or mechanical forces. This improved durability includes vibration dampening. This trait is especially critical to protect delicate components from the extreme stresses brought on during flight.
Related Article: Testing the Thermal Compatibility of Polymeric Microspheres
Microspheres aren't rocket science, but they are instrumental to it. As a quick summary, their benefits to aviation alone include:
- Weight Reduction
- Material Cost Reduction
- Thermal Management
- Vibration Protection
- Improved Control over Rheology and Application
- Improved Durability and Impact Dampening
Your organization doesn't need to do rocket science to experience these benefits either. Microspheres are easy to apply across a wide range of applications. If you're interested in learning more about microsphere and how they can fit into your operation, reach out by leaving a comment below or pressing the contact us button. Our specialists would be happy to discuss the best solution for your needs.
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