In this article, we will explore the following topics:

• Why modern appliances, especially those designed for commercial use, can create excessive noise and vibration for operators and customers.
• How certain acoustic materials, including melamine and hydrophobic melamine foams, are used to absorb airborne sound. Vibration damping materials can also help prevent resonance.
• When custom molded foam solutions designed by our PMP division may be necessary to address specific energy management challenges where precision is a must.

 

Commercial blenders and grinders are engineered for durability and performance in high-use settings. However, the same power that enables them to process dense materials efficiently also generates substantial airborne and structural noise. In cafés, restaurants, and even office breakrooms, this noise can interfere with conversation, harm concentration, and diminish the user experience.

For manufacturers, a loud appliance is a design flaw that could hurt brand perception. Many are increasingly focused on acoustic engineering as a core part of appliance design. And this is where Polymer is often called to help. We’ll identify common sources of noise for commercial blenders and grinders and explore insulation materials and solutions for absorbing sound and controlling vibration.

Acoustic Challenges in Appliances

Engineers tasked with reducing noise in a new or existing appliance product will likely target three common sources to identify where it originates:

Motor Noise

The motor provides the power needed to blend dense or frozen ingredients efficiently. Even without a load, it produces a steady hum caused by electromagnetic vibrations as electrical currents interact with magnetic fields. Because the motor relies on airflow for cooling, it can’t be completely sealed off, which presents an acoustic challenge: air vents that help manage heat also allow noise to escape.

Blade or Grinder Interaction

The loudest noise will come from the blades in a blender or the burrs in a grinder. When these components process hard materials, they generate significant impact and friction noise.

Structural Vibration and Resonance

Motor vibrations travel through the appliance’s frame and housing during operation. When these vibrations match the natural resonant frequency of a structural component, that part begins to oscillate more intensely, producing audible rattling or buzzing. This resonance effect can amplify both the motor’s hum and the noise generated by the blades.

Acoustic and Damping Materials to Bring the Noise Down

Mitigating noise requires addressing both airborne sound and structural vibration. Advanced acoustic foams and damping materials are among the most effective solutions available to appliance manufacturers.

Insulation Foams to Absorb Airborne Noise

Melamine foam is a lightweight, open-cell material widely used for acoustic insulation. Its porous structure traps sound waves, converting their energy into heat and preventing noise from escaping the appliance. When applied around the motor compartment or along walls of the appliance, POLYDAMP® Melamine Foam (PMF) helps reduce noise without adding significant weight or bulk.

Of course, many foodservice and kitchen environments involve a lot of moisture, which requires a slightly different material. Hydrophobic melamine foam maintains all the acoustic benefits of standard melamine while repelling water and resisting mold growth. POLYDAMP® Hydrophobic Melamine Foam can stay dry and stable under frequent use and cleanings to ensure performance.

Custom Molded Foam for Precise Absorption

In some cases when a custom solution is required, our PMP division can develop a molded foam solution for a specific appliance application. With custom molded foam, engineers can pinpoint the exact composite and shape to mitigate structural vibration and reduce noise. It is often paired with damping materials or can be used as an alternative for preventing resonant vibration.

By choosing a custom solution for motor housing, manufacturers can enjoy fewer parts and components, streamlined assembly, and effective sound absorption and vibration mitigation for a quieter end product.

Our custom molded foam solutions for modern appliances include the following:

• POLYFORM® High-Density Molded Foam – Integral Skin (PHDM-IS)
• POLYFORM® High-Density Molded Foam – Non-Skinned (PHDM-NS)
• POLYFORM® Low-Density Molded Foam – High Resilient (PLDM-HR)

We have partnered with appliance manufacturers for custom molded solutions to solve a wide range of energy management challenges.

Vibration Damping Materials for Structural Shocks

While melamine foam manages airborne sound, vibration damping materials reduce structure-borne noise. High-density viscoelastic foams or elastomeric pads absorb mechanical energy and convert it into heat before it absorbs through the housing. A POLYDAMP® V-0 Extensional Damping Pad (EDPV0) helps prevent resonance to reduce airborne sound.

EDPVO, along with our melamine foams and aluminum film facings, all carry a UL 94 V-O rating, which is critical for fire safety and compliance. This rating signifies that the material self-extinguishes and does not produce any flaming drips. Our vibration and sound absorption materials provide excellent thermal control based on the latest regulations and appliance industry standards.

Finding the Right Insulation Solution for Quieter Appliances

If a product is making too much noise that creates a difficult user experience, let the experts at Polymer take a look at what might be causing the issue. We were asked to do this for a high-end blender manufacturer and ultimately determined that the commercial appliance needed a few modifications for a quieter experience.

• We counseled the manufacturer on creating a tortuous path for the air inlet to ensure optimal cooling without sound escaping from the base openings.
• We contour-cut PHM at a 45-degree into a funnel shape in the base of the blender to create clearance for a sound baffle.
• Damped rubber feet used by the manufacturer helped minimize movement and vibration amplification.
• An enclosure was added around the blender to reduce airborne sound generated by the blades and motor.

In this particular solution, the manufacturer was able to ensure operators could operate the high-speed blender at the lowest sound level possible, providing a quieter environment for customers without compromising on safety.

Contact us today to learn more about our acoustic and damping solutions for today’s modern appliances. No matter the challenge, our engineers will find the right materials to address your energy management needs.