To understand the challenges that arise on the quality front, you first have to understand how polyester acoustic panels are made.
1. Define the desired outcome
The process to create a finished acoustical panel starts with determining what characteristics we want the finished panel to have. We can affect acoustical curves (NRC), stiffness, surface texture, or color by changing the fiber material or size, product density or thickness, or manufacturing processing of our finished panels. Each variable lets us dial in the ideal finished characteristics. Our standard Eco panels are comprised of recycled polyester fiber and special lower melting point polyester fiber.
2. Manufacture the needle punch felt
Next, we start the manufacturing process. Every polyester acoustic panel starts out life as a nonwoven, needle punch felt. This felt is similar to the felt kids make craft projects out of, but much thicker and denser!
We begin by taking raw fiber and turning it into a “web”. We then build density and surface characteristics by adding batts and needling the material together. The repeated needling that the felt receives is one of the keys to creating a stiff panel while maintaining a super smooth-surfaced panel. From this process, we create a “master roll” of felt.
The felt moves to the heat-setting machinery following the creation of the master roll. This could be a mold for 3d shaped panels or some form of flat pressing system. This process changes the material from a roll of flexible felt to a stiff polyester acoustic panel.
When heat hits the polyester fibers, they melt and flow like a liquid thermo-plastic. Fibers like these are specially designed to have a low melt point. As this material cools, it turns back into plastic but is now spread throughout the felt, attached to all the fiber around it, and (with the assistance of the needling) creates the stiffness of the finished acoustic panel.
The heat-setting process is one of the most difficult to perfect. This is because the material will shrink three-dimensionally while being heated. And any imperfections in needling will create very obvious surface defects.
The final manufacturing step is to cut the panels to their final dimensions or shape. Most architects and interior designers need tolerances of +/- 1/8th of an inch. Some elaborate designs require tighter than +/-1/16th of an inch. This would normally favor a die-cutting process but in many cases, the variety of shapes and rectangular dimensions needed would make this cost-prohibitive. Only with extremely precise cutting tools such as CNC machinery using oscillating blades, lasers, or waterjet cutting can near-perfect acoustical panels be cut every time.