Is perforated metal outdated? Exploring new soundproofing material options

Perforated metal is commonly used for the inner walls of soundproof rooms and covers. It is a material made by punching small holes in steel, stainless steel, or aluminum plates. When paired with an acoustic or air layer on the backside, it functions based on the Helmholtz resonator principle. However, since the non-perforated areas reflect sound, attention must be paid to the open area ratio.

Advantages of Perforated Metal

Protects soft sound-absorbing materials.

Can be designed to preserve acoustic performance (Helmholtz effect).

While perforated metal appears to offer many benefits, we do not recommend it for every project. The reason is that it can be very expensive, and the results may not always justify the cost.

The Problem of High Cost 

At our company, we own turret punch presses in-house, allowing us to manufacture perforated metal ourselves and offer it at relatively low cost. However, companies without such equipment must purchase expensive commercial perforated metal. Especially in large-scale soundproof rooms or covers, the cost becomes a major burden.

What are the Alternatives to Perforated Metal? 

The role of perforated metal is to protect the sound-absorbing material while maintaining its performance. However, we propose an innovative alternative product called “BFB.” BFB is made from high-density glass wool with a surface layer of durable Tyvek fabric. It is also certified as non-combustible, making it an ideal material for the interior walls of soundproof rooms.

Advantages of BFB

Lightweight and easy to handle.

Highly resistant to scratches and damage, ensuring long-term durability.

Waterproof, preserving sound absorption performance.

Significantly more cost-effective than perforated metal.

Complies with ISO Class 5 (ISO 14644-1) and Class 100 (Fed-Std-209E) standards. *Under certain conditions

For example, the larger the soundproof room or cover, the more surface area is required for sound absorption—and thus more perforated metal is needed. By switching to BFB, it is possible to reduce costs by several million yen. Furthermore, unlike perforated metal, which can weigh hundreds of kilograms, BFB is lightweight and easy to install.

Toward a New Standard 

Although BFB was only launched at the end of 2020, it has already been widely adopted. We aim to promote it as a next-generation soundproofing material to replace perforated metal.