Vibration Dampers for Structure-Borne Noise

Vibration DampersVibration dampers dissipate the energy that causes resonant vibrations in built structures. Vibration, a back-and-forth movement or oscillation, produces structure-borne noise in machine enclosures, engine bays, generator sets, heavy trucks, military vehicles, and many other applications. Vibrations can also damage parts, loosen fasteners, weaken soldered connections, and suggest poor quality.

For engineers, it’s important to understand that objects have a frequency at which vibration occurs. With resonant vibrations, multiple objects vibrate at the same frequency. For example, the low-frequency rumble of a big diesel engine can cause a vehicle’s windows to rattle. These vibrations don’t just produce unwanted sounds. They can also damage the window glass.

In this article, the last in a series about custom acoustic insulation, Elasto Proxy explains what engineers need to know about the different types of vibration dampers. You’ll also learn how this type of custom acoustic insulation is cut from sheets and bonded to other types of materials.

Types of Vibration Dampers

Vibration dampers are made of extruded vinyl, asphalt-impregnated paperboard, metal foil, or fiberglass.

Extruded vinyl dampers are flexible, lightweight, and available in grades that meet specific standards. For example, vinyl that meets UL 94 V0 flammability requirements is used in hospital equipment, kitchen appliances, and computer housings. Vinyl that meets ASTM E662 for the optical density of smoke and ASTM 162 for surface flammability is used in buses, trains, and subways.

Asphalt-impregnated paperboard dampers are odorless, wear-resistant, waterproof, lightweight, and  cost-effective. Like extruded vinyl, they’re supplied in sheets that can be cut to size and then laminated to other materials. For example, asphalt-impregnated paperboard can be laminated to sound barriers. Asphalt-impregnated paperboard can also be bonded to flat or curved panels in built structures.

Metal foil dampers can be applied directly to structural components or bonded to other types of insulating materials. For example, aluminum foil can provide the facing for a sandwich-like structure that includes a sound absorber and a heat blocker. To support vibration damping, metal foils can be embossed so that raised features in the foil disrupt sound waves as they travel across the surface.

Fiberglass dampers are made of a reinforced plastic that’s composed of glass fibers embedded in a resin matrix. These thin, composite materials include laminates with a viscoelastic compound that’s sandwiched in the center. For optimum damping performance, both outer layers of the fiberglass may have the same thickness. Applications include acoustic hoods and housings.

How Vibration Dampers are Made

Vibration dampers are cut from sheet materials and can be laminated to other types of insulation. They can also feature a release liner with a pressure-sensitive adhesive (PSA) for peel-and-stick installation. For engineers, it’s important to understand how choosing the right fabrication method affects cost, consistency, and quality.

Cutting can be done in-house or by a custom fabricator. Manual cutting with a knife, saw, or other hand tools may seem cost-effective, but poor-quality cuts can result in rework and material waste. By contrast, water jet cutting creates fine, fast, consistent cuts that maximize material yields. Plus, unlike die cutting, there’s no paying for or waiting for tooling with water jet technology.

Laminating combines vibration dampers with other types of materials in a sandwich-like structure. To avoid delamination, this bonding process requires the right adhesives and the efforts of skilled production personnel. Some vibration damping materials, such a fiberglass with a viscoelastic core, are laminated when they’re manufactured. Other vibration dampers are laminated during custom fabrication.

Find Vibration Dampers for Structure-Borne Noise

The article you’ve been reading is the last in a series about how to stop noise with custom acoustic insulation. For more information, please contact Elasto Proxy. You can also ask for the Elasto Bag to see some sample insulation for yourself.

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Sound Barriers for Noise Control

Sound BarriersSound barriers are custom acoustic insulation that blocks sounds instead of absorbing or damping them. They’re made of dense materials and are used at the source of a sound and along its path. To choose the right noise control product, engineers need to understand how sound barriers work, how they’re made, and the different types that are available. Continue reading Sound Barriers for Noise Control

Sound Absorbers for Noise Control

Sound AbsorbersSound absorbers are custom acoustic insulation that absorbs sounds instead of blocking or damping them. They’re made of foams and facings and used at the source of the sound and at its receiver. To choose the right noise control solution, engineers need to understand how sound absorbers work, which types are available, what questions to ask during material selection, and how sound absorbers are made. Continue reading Sound Absorbers for Noise Control

Stop the Noise with Custom Acoustic Insulation

Custom Acoustic InsulationCustom acoustic insulation absorbs, transmits, or redirects sound waves – vibrations in the air that pass-through objects and result in audible sound. Noise, or unwanted sound, is measured in decibels (dB) and has a specific frequency distribution that’s measured in Hertz (Hz).

Unlike some noise control products, custom acoustic insulation can be “tuned” to address specific frequencies. Examples include the low-frequency rumble of a big diesel engine and high-frequency sounds like squeaking and squealing.

Custom insulation can strengthen product designs, but engineers need to know which questions to ask and what types of solutions are available. In this introductory article, you’ll learn about the basic elements of noise control. You’ll also learn about the basic types of acoustical materials and how they’re fabricated. Continue reading Stop the Noise with Custom Acoustic Insulation

Cold Bonding vs. Injection Molding for Finished Gaskets

Finished Gaskets - BlogCold bonding for finished gaskets joins cut lengths of rubber without the use of heat. This bonding technique isn’t performed under low-temperature conditions but is manual process that requires a brush and glue. By contrast, injection molding is a semi-automated process that uses a C-press machine with a heated barrel, metal plates, and tons of pressure. To join cut lengths, uncured rubber is used.

By understanding how these joining processes work, engineers can make better decisions about which types of finished gaskets to choose. It’s also important to understand the advantages of disadvantages of each bonding technique. In this week’s article, we’ll compare cold bonding with injection molding in terms of capabilities, costs, and quantities. Continue reading Cold Bonding vs. Injection Molding for Finished Gaskets

Hot Splicing vs. Vulcanizing for Bonded Gaskets

Bonded GasketsHot splicing uses heat, pressure, and a film splice to join the ends of rubber profiles into bonded gaskets. This joining technique uses either a conventional heating source or infrared (IR) light and polyethylene (PE) film. Hot splicing creates strong bonds at the molecular level and generally provides better results than vulcanization, a bonding technique that uses uncured rubber instead of a film splice.

Choosing the best way to bond rubber gaskets can be a complex decision, however. The profile material is just one of many considerations. You also need to consider the size and shape of the seal, production quantities and costs, and the way that lengths of rubber are cut. In addition, it’s important to inspect and install your gaskets properly to ensure reliable sealing and prevent avoidable waste.

Is hot splicing better than vulcanizing for the rubber gaskets that you need? Let’s take a closer look. Continue reading Hot Splicing vs. Vulcanizing for Bonded Gaskets

What’s the Best Way to Bond Rubber Gaskets?

Bonding GasketsRubber profiles come in lengths that are cut-to-size and fabricated into finished gaskets. Examples include picture frame or bezel gaskets, O-rings, and gaskets with rounded corners.

There are four ways to bond or join the ends of rubber profiles.

  • Hot Splicing
  • Vulcanization
  • Cold Bonding
  • Molding

Each bonding or joining method has its advantages, but what’s the best choice for your application? Let’s examine each method in detail so that you can make the right decision. Continue reading What’s the Best Way to Bond Rubber Gaskets?

Rubber Floor Mats Reduce Wear, Danger, and Noise

Rubber Floor MatsRubber floor mats for mobile equipment protect cabin floors from damage and operators from slip-and-fall hazards. Rubber flooring that’s laminated to acoustic insulation also absorbs noise from the engine compartment, which is often directly below the cab where the operator sits. Rubber matting can even be used as a kick-plate to protect cabin walls from contact with an operator’s boots.

For mobile equipment manufacturers, choosing the right type of cabin flooring is an important design consideration. The metal floors that are used inside a cab are durable, but operators track mud, snow, dirt, and water inside. Rubber floor mats can protect these metal surfaces from rust, corrosion, and scratching. Sheet metal flooring can become slippery, but rubber surfaces can offer surer footing.

As manufacturers are discovering, rubber floor mats are part of a complete cabin solution that promotes operator safety and equipment performance. By understanding how rubber flooring is designed and made, manufacturers can determine if a custom-fabricated solution is the right choice. For starters, however, engineers may want to compare rubber to other flooring materials. Continue reading Rubber Floor Mats Reduce Wear, Danger, and Noise

Custom Cab Insulation Reduces Sound, Costs, and Mistakes

Custom Cab InsulationCustom cab insulation absorbs sound and provides a finished appearance to mobile equipment interiors. This acoustic insulation can be cut by hand and applied with spray adhesives, but that process is expensive, wasteful, and even hazardous to human health. Plus, manual cutting can result in cabin insulation that’s unappealing. Buyers who see mis-cuts may question the quality of your overall equipment design.

As mobile equipment manufacturers are discovering, there’s a better way to design and build quieter cabs. Custom-fabricated insulation that’s waterjet cut creates straight lines and chamfered angles. There’s less material waste, reduced cutting times, and closer control of material usage. Engineers can also get design assistance and help with material selection. Installers can avoid messy, toxic spray adhesives.

Parts marking, kitting, and packaging provide benefits, too. By taking a closer look at how custom-fabricated cab insulation is made, you can determine if it’s the right choice for your company. Continue reading Custom Cab Insulation Reduces Sound, Costs, and Mistakes

Engine Compartment Insulation for Heat and Noise Reduction

Engine Compartment InsulationEngine compartment insulation keeps heat and noise in the engine bay from reaching a vehicle’s interior. Thermal insulation protects drivers, operators, and passengers from high temperatures that can also damage on-board electronics such as GPS tracking systems. Acoustic insulation dampens damaging sound-induced vibrations and protects personnel from decibel levels that can harm human hearing.

With forestry equipment, military land systems, and other types of mobile specialty vehicles, the cab where the operator sits is usually next to the engine compartment. If the cab is directly above the engine bay, installing thermal-acoustic insulation under the cabin floor is a smart choice. Cabin insulation supports additional noise reduction. Inside the engine compartment, insulation is attached to the firewall.

For mobile equipment manufacturers, choosing the right engine bay insulation is an important design consideration. Product designers and engineers need to understand their options, but it’s also important to understand how thermal-acoustic insulation is made. Engine compartment insulation that’s custom-fabricated doesn’t just reduce heat and sound. It helps you to control costs and improve quality. Continue reading Engine Compartment Insulation for Heat and Noise Reduction