1. What is the difference between egg crate foam and regular foam, and how much better is the sound absorption?
Egg crate foam has a convoluted, wave-shaped surface (like an egg tray) that increases the contact area with sound waves and lengthens the reflection path. Its open-cell structure converts sound energy into heat, so its sound absorption (especially in the mid and high frequencies) is clearly better than flat regular foam. It is more suitable for recording studios, KTV rooms, equipment rooms, machine noise reduction and cushioning for precision packaging. Regular foam is mainly used for filling or simple cushioning.
2. How do I judge sound absorption performance, and how do I choose density and thickness?
Key parameters are density (commonly 18-35 kg/m3 or higher), thickness (commonly 2-5 cm, measured by overlapping two peaks), open-cell ratio and NRC (noise reduction coefficient). Moderate density combined with sufficient thickness and a high open-cell ratio performs better in the low and mid frequencies. When purchasing, ask the supplier for a sound absorption coefficient report at specified frequencies, or third-party testing such as SGS.
3. Is it flame retardant? What certifications are available? Can it be used for export?
Standard PU egg crate foam is not flame retardant. Flame retardants must be added to achieve self-extinguishing properties (Class B1, UL94, etc.). Exports to Europe and the US often require flame retardant reports, RoHS, REACH and VOC compliance documents. Manufacturers in Shanghai and the Yangtze River Delta region (e.g. suppliers in Pudong, Changzhou and Zhejiang) usually offer flame retardant customization together with test reports.
4. Can it be customized, and what services are included?
Yes, it can be customized to your requirements. Standard services include die-cut special shapes according to drawings, bevel and wedge processing, self-adhesive backing (for easy mounting), foaming in different densities, colors, and lamination with fire-retardant fabric.