Anechoic Chamber
Polyurethane (PU) foam plays a critical role in the design of anechoic chambers, where it is used as a sound-absorbing material. These chambers are designed to eliminate sound reflections and external noise, creating an acoustically “dead” environment—ideal for testing microphones, speakers, sonar devices, or conducting psychoacoustic experiments.
Description
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
Automotive Cushioning
Automotive CushioningPolyurethane (PU) foam is a key material in automotive cushioning due to its excellent balance of comfort, durability, and cost-effectiveness. Here’s a breakdown of its applications, benefits, and technical considerations in the automotive sector:
Mattresses
MattressesPolyurethane foam is one of the most commonly used materials in the mattress industry, known for its comfort, support, adaptability, and cost-effectiveness. It serves as a core material or comfort layer in many types of mattresses, including all-foam, hybrid, and spring-based mattresses.
Interior Trim And Upholstery
Interior Trim And Upholstery
Interior Trim And Upholstery
Interior Trim And UpholsteryPolyurethane (PU) foam is a fundamental material in automotive interior trim and upholstery, providing essential comfort, cushioning, and aesthetic appeal. Its versatility, durability, and ability to be customized in firmness and density make it ideal for seats, door panels, headliners, and other interior components.
Upholstered Furniture
Upholstered Furniture
Upholstered Furniture
Upholstered FurniturePolyurethane foam is a widely used material in the upholstery and furniture industry due to its versatility, comfort, durability, and cost-effectiveness. Here’s a comprehensive breakdown of its application and usage:
There are two main types:
Flexible polyurethane foam (FPF) – Soft and used in cushions, mattresses, etc.
Rigid polyurethane foam – Used for insulation and structural applications, not typically for furniture.
