How Are Acoustic Panels Made?

📖 Reading time: 6 min and 43 sec

As a child, did you belong to the group of kids who felt the insatiable urge to take apart their toys just to understand their inner workings? Although it may have caused you a fair bit of trouble, the knowledge gained was undoubtedly invaluable.

Today, we are going to channel this innate curiosity to take you on a journey through the manufacturing process of acoustic panels. Rest assured, not a single panel was harmed during the creation of this article.

Join us as we delve behind the scenes to explore the intricate process of crafting acoustic panels.

 

What Are Acoustic Panels Used For?

Acoustic panels are designed to control sound within a space. They reduce echo and reverberation, making them ideal for recording studios, home theatres, offices, and any area where sound quality is crucial. By improving speech clarity, reducing noise pollution, and creating a more pleasant auditory environment, acoustic panels contribute significantly to the overall sound experience.

 

Acoustic Panels vs. Soundproofing

While often used interchangeably, acoustic panels and soundproofing serve different purposes. Acoustic panels manage sound within a room by absorbing and diffusing sound waves to reduce echo and improve clarity. Soundproofing, on the other hand, aims to prevent sound from entering or leaving a room. For best results, it’s essential to understand when to use each method. Soundproofing typically involves more substantial modifications, such as adding mass to walls or sealing gaps, while acoustic panels are easier to install and focus on improving the sound quality within a space.

 

 

Types of Acoustic Panels

There are various types of acoustic panels, each serving different purposes and offering unique benefits:

1. Wood Perforated Acoustic Panels: Made of MDF and foam, combining aesthetic appeal with functionality.
2. Standard Foam Panels: Cost-effective and efficient, made from polyurethane foam.
3. Textile Panels: Featuring a core of technical polyurethane acoustic foam wrapped in fabric.
4. PET-Felt Panels: Made from recycled PET materials, eco-friendly and effective.
5. MDF and PET-Felt Panels: Combining MDF with PET-felt backing, like HEXYBEL panels.
6. Slatted Wood Panels: Offering a blend of sound absorption and diffusion.

 

How Acoustic Panels Work

Acoustic panels absorb sound waves that strike their surface, reducing the amount of sound that reflects off walls, floors, and ceilings. This absorption decreases echo and reverberation, improving sound clarity. The materials and construction of the panels play a significant role in their effectiveness, with different materials offering varying degrees of sound absorption and diffusion.

 

 

Materials Used in Acoustic Panels

Different acoustic panels are made from various materials, each with its own acoustic properties:

• MDF (Medium Density Fiberboard): Durable and acoustically effective.
• Polyurethane Foam: Excellent sound absorption.
• PET Felt: Eco-friendly and efficient.
• Fabric: Enhances aesthetic appeal and provides additional sound absorption.

 

Manufacturing Process of Acoustic Panels

Wood Perforated Acoustic Panels

Wood perforated acoustic panels are crafted from MDF (Medium Density Fiberboard). The process begins with the selection of high-quality MDF, which is known for its durability and acoustic properties. The MDF sheets are then perforated with precision machinery to create an array of holes. These perforations allow sound waves to pass through the surface and be absorbed by the foam backing. The foam, usually made of polyurethane, is adhered to the MDF, providing additional sound absorption. The final step involves finishing the panels with a veneer or paint, enhancing both their aesthetic appeal and durability. These panels are often used in auditoriums and conference rooms, where both appearance and performance are crucial.

 

Standard Foam Panels

Standard foam panels are typically made from polyurethane foam, known for its excellent sound absorption properties. The manufacturing process begins with the creation of the foam, which involves a chemical reaction between polyols and diisocyanates. This reaction produces a foam that is then poured into moulds of various shapes and sizes. The foam is allowed to cure and solidify before being cut into panels. Some manufacturers may also treat the foam with fire retardants to enhance safety. Standard foam panels are highly effective in absorbing mid to high-frequency sounds and are commonly used in recording studios and home theatres.

 

 

 

Textile Panels

Textile panels consist of a core of technical polyurethane acoustic foam wrapped in a fabric cover. The process begins with the production of the foam core, similar to standard foam panels. Once the foam cores are cut to size, they are covered with a layer of fabric. The fabric not only adds to the visual appeal but also contributes to the sound-absorbing capabilities of the panel. The fabric is often chosen for its acoustic transparency, allowing sound waves to pass through and be absorbed by the foam core. Textile panels are versatile and can be used in various settings, from offices to home entertainment rooms.

 

PET-Felt Panels

PET-felt panels are made from recycled PET (Polyethylene Terephthalate) materials, making them an eco-friendly choice. The manufacturing process starts with the collection of PET materials, which are then cleaned and shredded into small flakes. These flakes are melted and extruded into thin fibres, which are then bonded together to form a dense, fibrous panel. The resulting PET felt is cut into panels of various shapes and sizes. PET-felt panels are effective in absorbing sound and are often used in open office spaces and classrooms. They are also popular for their environmental benefits and sustainability.

 

 

Wood Slatted Panels & HexyBEL

Panels like HexyBEL and wood-slatted panels combine the durability of MDF with the sound-absorbing properties of PET-felt. Slatted wood panels consist of wooden slats mounted on a backing material, often foam or felt. The manufacturing process begins with the selection of high-quality wood, which is then cut into slats of various sizes or into hexagons needed for HexyBEL panels. These slats and plates are attached to a backing material that provides additional sound absorption. The MDF surface diffuses sound waves, while the backing material absorbs them, providing a balanced acoustic treatment. Slatted wood panels and its upgraded version - HexyBEL, are ideal for spaces requiring both sound absorption and diffusion, such as concert halls and high-end home theatres.

 

Wood Wool Acoustic Panels

The production begins with selecting high-quality wood, usually spruce or pine. The wood is shredded into thin, curly fibres known as wood wool. The wood fibres are then mixed with a mineral binder, typically cement, which acts as both a binder and a fire retardant. The ratio of wood wool to cement can vary, but it is usually around 60-70% wood wool to 30-40% cement. The mixture is poured into moulds to form panels of various sizes and thicknesses. The moulds are then subjected to high pressure to ensure the fibres are thoroughly bonded and the panels have a uniform density. The pressed panels are left to cure for several days. During this time, the cement hardens, and the panels gain their structural integrity. This curing process is crucial for achieving the desired acoustic and thermal properties. Once cured, the panels are removed from the moulds and trimmed to the desired dimensions. They can be left in their natural state or painted in various colours to match different interior designs.

 

 

Benefits and Disadvantages of Acoustic Panels

Benefits:

• Improved sound quality and clarity
• Reduced echo and reverberation
• Enhanced aesthetic appeal
• Versatile applications in various environments

Disadvantages:

• The initial cost can be high
• Installation may require professional assistance
• Not a substitute for complete soundproofing

 

Where to Place Acoustic Panels

For optimal performance, place acoustic panels on walls and ceilings where sound reflections are most prominent. Common placement areas include:

• Behind speakers
• Opposite reflective surfaces
• On side walls at ear level
• On the ceiling above the listening or seating area

 

 

DIY Acoustic Panels: Are They Worth It?

DIY acoustic panels can be a cost-effective solution for those on a budget. However, they may not offer the same level of performance as professionally manufactured panels. If you have the skills and materials, DIY panels can be a worthwhile project, but for best results, investing in high-quality panels is recommended.

 

Testing of Acoustic Panels

Before acoustic panels reach the market, they undergo rigorous testing to ensure their effectiveness in sound absorption and diffusion. These tests are conducted in controlled environments to measure the panels' performance across various frequencies. Key metrics evaluated include the Noise Reduction Coefficient (NRC) and Sound Absorption Coefficient (SAC), which indicate how much sound the panel can absorb. For example, panels with an NRC of 0.75 absorb 75% of the sound waves that strike them. Additionally, flame resistance and durability tests are performed to ensure safety and longevity. This comprehensive testing guarantees that the panels meet industry standards and deliver reliable acoustic performance.

 

 

Interesting Facts About Acoustic Panel Production. Did You Know That?

1. Some acoustic panels are made from 85% recycled materials. This includes products like PET-felt panels, which are crafted from recycled plastic bottles.

2. Producing perforated wood acoustic panels creates thousands of tiny holes. These perforations can total up to 30% of the panel's surface area, enhancing sound absorption while maintaining a natural wood appearance.

3. Acoustic foam panels undergo a special curing process. This process ensures they have the optimal density and cellular structure for effective sound absorption, typically reducing noise levels by up to 50%.

4. Textile-wrapped acoustic panels are tested for both fire resistance and acoustic performance. They often meet stringent safety standards, making them suitable for commercial and public spaces.

5. The manufacturing process for PET-felt panels includes melting and extruding recycled plastic. This method transforms plastic waste into durable, sound-absorbing panels, contributing to a circular economy.

6. HexyBEL acoustic panels require precise cutting and finishing. Each hexagon-shaped plate must be accurately spaced to ensure optimal sound diffusion, which helps create a balanced acoustic environment.

7. Ceiling baffles can be customised to fit specific room dimensions. This customisation ensures maximum sound absorption and aesthetic integration into various architectural designs.

8. The production of bass traps involves creating materials with high mass and density. These properties are essential for absorbing low-frequency sounds, which are often the most difficult to control.

9. Acoustic panel manufacturers often conduct reverberation chamber tests. These tests measure the effectiveness of panels in reducing sound reflections, providing data on their performance in real-world scenarios.

10. Some high-end acoustic panels are handcrafted. This artisanal approach allows for meticulous quality control and the creation of unique, aesthetically pleasing designs that also deliver superior sound absorption.