Give Shape to your ideas in Composite Materials

Simply put, a composite is a combination of various components. In the industry, composite material are materials made by combining two or more natural or artificial elements (with different physical or chemical properties) that are stronger as a team than as individual players. The component materials don’t completely blend or lose their individual identities; they combine and contribute their most useful traits to improve the outcome or final product. Composites are typically designed with a particular use in mind, such as added thermal insulation, electric insulation, mechanical strength, durability, chemical resistance or more importantly manufacturability.

Composites, also known as Fiber-Reinforced Polymer (FRP) composites, are made from a polymer matrix that is reinforced with an engineered, man-made or natural fiber (like glass, carbon, cotton or aramid) or other reinforcing material. The matrix protects the fibers from environmental and external damage and transfers the load between the fibers. The fibers, in turn, provide strength, stiffness, temperature or even fire resistance to reinforce the matrix—and help it resist cracks and fractures.

Not all plastics are composites. In fact, most plastics—the ones used in toys, water bottles and other familiar items—are not composites. They’re pure plastics. But many types of plastic can be reinforced to make them stronger. This combination of plastic and reinforcement can produce some of the strongest (ex: mechanical, electrical, thermal higher resistance), most versatile materials (for their weight) ever developed by technology. Polymer resins (such as polyester, vinyl ester, epoxy or phenolic) are sometimes referred to as plastic.

Composites offer advantages over to other materials like aluminium - wood: Composites are strong, yet flexible – Composites ski poles, for instance, usually offer more flexibility and durability than standard aluminum ones: They can bend significantly without snapping. Composites are excellent at insulation - Fiber based products have a very low coefficient of thermal conductivity (up to 0.18–0.3 W/mK) or unparalleled dielectric strength (up to 30 KV/mm thickness). Compared to conventional materials such as steel (15–58 W/mK), composites the avoidance of thermal or electric bridges. Composites are heat and electrical resistant – Composites retain their integrity when exposed to high temperatures or high voltages (ex: mica). Conversely, granite or magnetic surfaces can’t absorb heat or electricity, so they can chip if hot pans and high voltage are placed on them. Composites are non-porous – This makes them much more sanitary than granite, which can conceal bits of food and bacteria in its crevices. Composites also can withstand disinfectant and agressive chemical products without damaging the material, unlike granite. Composites are dimensionally stable – They retain their shape and size when they are hot or cool, wet or dry. Wood, on the other hand, swells and shrinks as the humidity changes. Composites are excellent at handling tension – In highly tension-loaded applications, such as the airplanes wing leading edges, railways component, this helps decrease fatigue and maintenance. Aluminum is sensitive to tension loads. Composites can create one-piece designs – Fabricating a product in one piece, whether it’s an airplane wing or a wind blade, reduces maintenance because there aren’t any fasteners or joints. Composites are long lasting – Wood eventually rots, but composites are durable. Think about the marine industry: Wooden boats require considerable care to last an owner’s lifetime, while many composite boats remain afloat for 50-plus years with routine maintenance. Composites are low maintenance – In an application such as a residential deck, this is critical. Composite decks can be cleaned with soap and water, while wood decks need to be regularly power washed, inspected for rot, sanded and stained. Composites offer endless appearance options – They can be easily formed into any shape and customized into any color, making composites a preferred choice for homeowners who want distinctive counters, shower surrounds, bathtubs and more. Granite must be carefully selected, matched and cut and is available in a limited number of colors. Composites are easy to maintain – They do not require sealants or special cleaning products. Because some alternative material are often porous, it must be sealed annually to prevent staining. And cleaning products such as degreasers and glass cleaners strip the sealant. Composites allow for precise weight distribution – In an application such as baseball bats, this allows for either balanced loading that contributes to an effortless, fast swing or end loading, which helps power hitters gain more distance. Aluminum alloy bats have less precise weight distribution. Composites absorb vibrations – Because they are non-elastic, composites dissipate the energy of vibrations, making them well-suited for applications ranging from equipment mounts to athletic shoe insoles. Aluminum doesn’t absorb vibrations as well as composites. Composites are easy to transport and install – Because they are lightweight, composites are an ideal replacement for steel in applications. They cost less to transport and are simpler to install in remote locations than their steel counterparts. Composites are inexpensive – Granite sinks or steel sheets, for example, routinely cost five to 10 times that of composite sinks. Plus, they require professional installation, which boosts the cost. Installing lightweight composite sinks can be a do-it-yourself project.

Any designer of composite parts and structures knows full well the challenges and opportunities posed by fiber-reinforced composite materials. The wide selection of resins, fibers, fiber formats and manufacturing processes allows a designer to custom-engineer a solution that puts fiber reinforcement exactly where it’s needed to meet a specific physical load (mechanical, thermal, electric or chemical). But designing for that fiber orientation is a complex and sometimes daunting task, fraught with potential for error that is best met by a well-trained, experienced designer working with complex CAD and CAE software. Dedicated simulation software are today capable to predict with a relative prevision the behavior and the life time of a part in fiber-reinforced material.

These same design challenges, than in the part design, exist when it comes to manufacturing with fiber-reinforced additive manufacturing, although the landscape is, in some ways, more complex (wide variety of material all with different manufacturing characteristics). A wide variety of machining technologies are possible : the traditional mechanical machine, the CNC milling, the laser cut or the jet water process (not exhaustive). Each approach is suitable for a given material and design but the combination of innovate and traditional techniques is often the success combo. The machining equipment suppliers attempt to help users with that decision via manufacturing simulation software. Such software, is typically proprietary and does not always make good decisions about the drill - tap and mill sequence selection or the machine settings - drill rotation speed, forward speed. A consequence is a degradation of the fiber reinforced material by the machining equipment. The machine operator expertise with strong programming skills will play an important role in the final setup of the equipment to guarantee the expected productivity. Thanks to his large knowledge of each material behavior and constraints during the process, he will fine-tune the strategy to successfully manufacture the final part.