This is the first in a two-part series about thermal acoustic insulation from Elasto Proxy, a global supplier of specialty “insulation sandwiches” that reduce both heat and sound.
Thermal acoustic insulation is used to reduce heat and sound in commercial, industrial, and military applications. In manufacturing and processing facilities, this multi-functional insulation is used with machine enclosures, pipes, and valves. On-road and off-road, composite structures that include both thermal and acoustic materials are also found in the floors, doors, side panels, and engine bays of mobile equipment and military vehicles.
Many different types of insulating materials are available, but you don’t need to have a PhD in material science to make the right choice. In this two-part series from Elasto Proxy, you’ll learn why you need thermal acoustic insulation, how thermal insulation and acoustic insulation work, and about two solutions from Elasto Proxy that may be right for your application. You’ll also learn how we manufacture these two products, and how we can custom-fabricate a specialty “insulation sandwich” to satisfy your application’s particular appetite.
Why You Need Thermal Acoustic Insulation
Thermal acoustic insulation may not be visible to machine operators or drivers, but product designs that fail to account for heat and noise put vehicles, equipment, and personnel at risk. Big diesel engines run loud and hot, and high levels of noise and heat can violate occupational safety standards and make driving uncomfortable or unsafe. Heat can also damage sensitive components such as electronics. If machine sensors or on-board GPS systems fail, downtime can hurt more than just the design team’s reputation.
For product designers, specifying the right kinds of materials for thermal acoustic insulation is critical. First, however, engineers need to ensure that they understand how thermal insulation and acoustic insulation work. Then, by choosing the right insulating materials, you can specify materials that meets all of your application’s requirements.
How Thermal Insulation Works
Thermal insulation reduces the transfer of heat between objects with different temperatures. According to the second law of thermodynamics, heat always flows in the direction of the object with the lower temperature (such as from a hot diesel engine to a cool passenger cab). Different materials conduct heat at different rates, however, so engineers need to consider the thermal conductivity of an insulator. It’s also important to remember that heat is transferred by conduction, convection, and/or radiation.
In layman’s terms, conduction is heat that’s transferred by direct contact. Convection is heat that flows or is blown through the air, and radiated heat is transmitted by infrared waves. By using different types of thermally-insulating materials, product designs can more fully address the heat source. For example, fiberglass is a good choice for reducing heat transfer from conduction and convection. For radiated heat, aluminum foil or Mylar provides a reliable, cost-effective solution.
How Acoustic Insulation Works
Acoustic insulation absorbs, transmits, or redirects sound waves – vibrations in the air that pass through objects and result in audible sound. Noise, or unwanted sounds, is measured in decibels (dBA) and has a specific frequency distribution. In outdoor environments, reflective and damping materials are used in structures such as highway noise barriers. For indoor and enclosed environments such as offices and engine bays, sound absorption and decoupling materials are used.
Sound absorbing materials include open-cell elastomeric foams such as polyester and polyurethane. When sound is absorbed, part of the sound energy is converted to a very small amount of heat. Acoustic insulation that’s made of open-cell foams absorbs this friction within the material’s cellular structure. Open-cell foams can absorb noise across a range of frequencies, but a foam’s sound-absorption profile is determined by factors such as cell size, porosity, material thickness, and material density. With decoupling, gaps in parts of the structure prevent the sound vibration from continuing along its path.
What to Expect In Part 2
In Part 2 of this series from Elasto Proxy, we’ll examine two thermal-acoustic insulation “sandwiches” that may meet your application requirements for a complete sealing and insulation solution. In learning about how these composite structures are made, you’ll also see how Elasto Proxy can custom-fabricate a specialty thermal-acoustic sandwich specifically for your application. Until then, please contact us for more information about thermal acoustic insulation.