Anechoic Chamber
Polyurethane (PU) foam plays a vital role in the engineering and performance of anechoic chambers, serving as one of the primary materials for effective sound absorption. These specialized chambers are designed to eliminate sound reflections, echoes, and external noise, creating an acoustically “dead” environment essential for high-precision audio testing. PU foam’s unique physical and acoustic properties make it the preferred material for lining walls, ceilings, and sometimes floors inside these controlled spaces.
In anechoic chambers, PU foam is typically manufactured in wedge or pyramid shapes, which increase surface area and enhance sound-absorbing efficiency.The foam absorbs a wide frequency range by trapping sound waves within its porous structure, converting acoustic energy into heat.This ensures minimal echo, extremely low reverberation time, and isolation from external noise. Such conditions are crucial for applications like testing microphones, speakers, hearing aids, communication devices, sonar systems, and conducting psychoacoustic or audio research experiments.
Description
PU foam used in these chambers is engineered for high sound absorption, flame resistance, and long-term stability, maintaining performance even under continuous acoustic exposure.
Its lightweight nature and ease of installation also make it a practical choice for constructing both full-scale professional anechoic chambers and smaller testing booths.
Whether in research labs, industrial testing facilities, audio product development centers, or defense and aerospace environments, PU foam remains an essential component for achieving the precise acoustic control required in modern sound analysis and testing.
Note: For low-frequency absorption, PU foam is often used alongside bass traps or hybrid materials like mineral wool or fiberglass.
Why Polyurethane Foam Is Used in Anechoic Chambers
PU foam is engineered into pyramid, wedge, or convoluted (egg crate) shapes to:
Absorb sound energy across a wide frequency range (especially mid to high frequencies)
Prevent sound reflections by diffusing and dissipating acoustic waves
Control reverberation time, ensuring a reflection-free environment
Improve sound isolation from external noise sources
Key Features of PU Foam for Acoustic Use
| Feature | Benefit |
| Open-cell structure | Traps and converts sound energy into heat, enhancing absorption |
| Lightweight & flexible | Easy to install, shape, and mount on walls, ceilings, and floors |
| Custom shapes (wedge/pyramid) | Enhances surface area for greater sound absorption |
| Frequency tuning | Foam thickness and shape can target specific frequency ranges |
| Fire-retardant grades available | Meets safety standards for industrial and commercial test environments |
Common Applications in Anechoic Environments
- Electroacoustic Testing (speakers, microphones, smartphones)
- Radar & RF Anechoic Chambers (with foam treated for electromagnetic absorption)
- Noise Measurement Chambers (automotive, appliance industries)
- Audio Product Development (headphones, studio monitors, hearing aids)
Specifications for PU Acoustic Foam in Anechoic Chambers
| Parameter | Typical Value |
| Density | 25–40 kg/m³ (1.5–2.5 lb/ft³) |
| Thickness | 2–12 inches depending on frequency coverage |
| NRC (Noise Reduction Coefficient) | 0.75–1.00 (varies by design) |
| Shape | Wedge, pyramid, egg-crate, or custom-molded |
| Fire Rating | UL 94 HF-1, FMVSS 302, or BS 476 Class 1 |
Advantages of PU Foam in Anechoic Chambers
- High acoustic absorption with minimal space requirement
- Customizable in shape, density, and thickness
- Cost-effective compared to alternative materials
- Non-dusting & safe for indoor use (when certified)
- Lightweight — ideal for suspended or mobile chambers
Related Products and Applications
Mattress Toppers
Mattress ToppersPolyurethane (PU) foam is a popular choice for mattress toppers because of its ability to enhance sleeping comfort, adjust firmness, and prolong the life of your mattress. PU foam mattress toppers provide an additional layer of cushioning, making any mattress feel softer, more supportive, and ergonomically balanced. Available in a variety of densities and formulations, including memory foam and high-resilience foam, PU foam can be tailored to meet individual sleep preferences.
Memory foam PU toppers contour to the body, providing targeted pressure relief for sensitive areas such as the shoulders, hips, and lower back, reducing discomfort and promoting restful sleep.High-resilience PU foam offers a bouncier, supportive feel, helping maintain spinal alignment and improving overall posture during sleep. Beyond comfort, PU foam mattress toppers help extend the lifespan of your existing mattress by absorbing daily wear and reducing sagging over time. They are lightweight, easy to install, and simple to maintain, often featuring removable, washable covers for hygiene and convenience.
Sofa
SofaPolyurethane (PU) foam is the most widely used material in sofa manufacturing, making it the top choice for sofa cushions, armrests, and backrests. Known for its perfect balance of comfort, durability, and affordability, PU foam provides consistent support and long-lasting performance, making it ideal for residential, commercial, and hospitality seating solutions. High-resilience (HR) PU foam is commonly used in sofa cushions for its firm, bouncy support that retains shape over years of use, while memory foam variants contour to the body to relieve pressure points and enhance ergonomic comfort.
This versatility allows PU foam sofas to cater to a wide range of preferences, from soft and plush seating to firm, orthopedic support. PU foam is lightweight, adaptable, and easy to mold, allowing manufacturers to craft sofas in various designs, shapes, and firmness levels. When combined with other materials such as latex, fiber, or pocket springs, PU foam delivers enhanced comfort, responsiveness, and structural integrity. Choosing PU foam for sofa cushions and backrests ensures long-lasting comfort, excellent support, and high value for money.
Filtration
FiltrationPolyurethane (PU) foam is widely used in automotive filtration systems due to its open-cell, reticulated structure that provides excellent airflow while effectively trapping dust, debris, and other contaminants. Lightweight, flexible, chemically resistant, and highly customizable, PU foam is an ideal material for both air and fluid filtration applications in modern vehicles.
Key Applications of PU Foam in Automotive Filtration
Engine Air Filters: PU foam is often used as a primary or secondary filtration layer in engine air filters. It efficiently traps coarse particles, protecting the engine from dust and debris while enhancing performance and longevity.
Cabin Air Filters: In HVAC systems, PU foam captures dust, pollen, and airborne particles, improving cabin air quality and passenger comfort. Its flexibility allows it to conform to various filter shapes, maximizing filtration efficiency.
Office Chairs
Office ChairsPolyurethane (PU) foam is one of the most versatile materials used in the production of ergonomic office chairs, offering a unique combination of comfort, support, durability, and adaptability. Designed to withstand long hours of sitting, PU foam provides the cushioning necessary to reduce pressure on the back, hips, and thighs while maintaining proper posture and ergonomic alignment.
Its high resilience and flexible properties allow chair manufacturers to create seats and backrests that conform to the body’s contours without losing shape over time.This ensures consistent support throughout the day, helping prevent fatigue, discomfort, and posture-related health issues.PU foam can also be formulated in varying densities, offering options from softer cushioning for comfort to firmer support for enhanced posture management.
