Quiet-Pro is a light weight, water resistant,
sound and energy absorbing panel system. It has principal uses as an acoustic
liner within air inlet trunks and other sea water exposed (occasional splash
wetting) areas. It is also used as an energy absorbing treatment to dampen sound
and vibration on thin panels, and as a light weight thermal treatment that does
not absorb condensation.
This product is made of expanded polypropylene pellets
formed into rigid boards. The technology is based on recent developments related
to energy absorbing plastics used for automobile crash protection. The material
exhibits high chemical and moisture resistance derived from the special
chemistry of the polypropylene resin.
These chemistry modifications also enhance
its unique sound absorption and damping properties. The material is molded using
a process of expanding polypropylene beads with hollow cavities.
beads are non-porous, but the hollow cores and cracks between adjacent beads
allow sound into a labyrinth-like path where energy is absorbed. The hydrophobic
nature of QuietPro allows sound absorption from a material that holds much less
water than fiber based acoustic materials. Sound absorption in 2" thickness
achieves a value of NRC = 0.50. This value provides good sound absorption in
moist applications, where fibrous or cellular foam materials cannot be used.
structural stability of QuietPro combined with its sound and energy absorbing
properties make it an ideal core material in marine interiors, machinery spaces,
etc.A comparison of wall panels using 1.75" core with .625" skin showed that QuietPro increased the sound transmission coefficient by 9dB due to its
excellent mechanical energy absorption characteristics. Because of its excellent
mechanical energy absorption characteristics QuietPro is an ideal light weight