Composite Materials: Lunch Is Served

What do composite materials have in common with lunch? Plenty, if you enjoy a sandwich for your mid-day meal. In material science, composites are made from two or more materials with different physical or chemical properties. Combining these ingredients forms a new substance with distinct, and hopefully superior, characteristics. Hungry for more information? Let's step into the kitchen and make a few ham sandwiches.

Building in Layers

Some people like open-faced sandwiches because there's fewer calories in one slice of bread than in two. Others prefer thicker sandwiches with three slices of bread, plenty of ham, and even some cheese and mayonnaise. No matter how you make your sandwich, the combination of layered ingredients produces a taste that's different than any one ingredient alone. Yet you wouldn't add jelly to a ham and cheese on wheat. Jelly provides flavor, of course, but it doesn't complement the other ingredients.

The texture, calorie count, and nutritional value of sandwiches can differ, too. Does that mean a ham sandwich is better than a slice of bread? Is a triple-decker sandwich better than an open-faced one? The answer depends upon your application requirements for lunch. The triple-decker may taste better and provide more carbohydrates and protein, but the open-faced sandwich is probably the right choice if consuming fewer calories is your goal. Still, it's unlikely you'd want to add jelly to either sandwich.

Sandwiches vs. Stews

If ordering lunch is this challenging, how can buyers select the right composite materials? Knowing your application requirements is important, but understanding this sandwich-like structure helps. Still, some buyers think that all composites have a stew-like structure instead. These so-called matrix materials do resemble a stew of sorts, perhaps one with bits of beef and potatoes "embedded" in a hearty broth. Yet just as stews can be served for lunch, they're not the only items on the menu.

Sandwich-like composites satisfy the appetites of applications that require thermal insulation, acoustic insulation, and/or vibration dampening. These composites aren't built with food, but consist of foams, fillers or barrier materials, and adhesives. Just as smoked ham tastes different than honey ham, foams made of ether, ester, and Triamid have different material properties. Just as you can make a sandwich with wheat or rye bread and mayo or mustard, you can choose different barriers, filler, and adhesives.

Meeting (Not Eating) Application Requirements

So what's the "secret recipe" for building the perfect sandwich-like composite for your insulation application? Balancing all of your requirements is critical. Just as you wouldn't add jelly to a ham and cheese sandwich, it's essential to avoid epoxy adhesives if you need to meet requirements for flame, smoke, and toxicity (FST). Today, buyers in industries such as mass transit and aerospace often choose water-based adhesives instead of products that use toluene or heavy metals.

Striking a balance between strength, toxicity, and the use of "green" materials can be difficult, but it's not the only challenge to overcome. What types of foam can you use? How many foam layers do you need? Do the barrier materials need to have a felt-like appearance, such as the headliner in a car? Do you need to bond the composite to a metal substrate and, if so, what is the metal's thickness? If the prospect of designing a ham sandwich seems more appetizing, you're not alone.

How Can We Help You?

Do you need to source composite materials for cars, tractors, or military transports? How about thermal insulation for engine compartments or acoustic insulation for the cabs of mobile specialty vehicles? Let's talk about how custom composites can meet your application requirements. For 25 years, Elasto Proxy has been solving challenges and providing solutions.

About the Author: Doug Sharpe is the President of Elasto Proxy, Inc. (Boisbriand, Quebec, Canada), supplier of sealing solutions and custom-fabricated rubber and plastic parts to a variety of industries, including green power, automotive, aerospace, and defense.