Skip to content
Telephone +44 (0) 1305 264669
Precision Acoustics

Aptflex F28P

Pyramidal structured absorber for radiation force balance targets for acoustic power greater than 2W but less than 100W/

This product is available to buy direct through our secure online shop.​

aptflex f28p tile


NPL Technology AppliedThe combination of the acoustic and physical properties of the Aptflex F28P acoustic absorber makes it the cost-effective solution for a Radiation Force Balance target for devices measuring acoustic power in the range 2-100W.

Physical specification

  • Based on a polyurethane rubber material, single-ply nominally homogeneous layer.
  • Pyramidal structured surface with maximum thickness of tiles: 8mm.
  • Tile dimensions: 200mm X 250mm x 10mm.
  • Coefficient of Linear thermal expansion: 200ppm/oC.
  • Specific gravity is 1.01g/cm3 is close to that of water.
  • Longitudinal wave speed (1-10MHz) is ≈1500 m/s.
  • Acoustic Impedance is 1.5 MRayls.
  • There is a resistance to Isopropyl Alcohol (IPA) and Trichloroethylene.
  • It can be affected by ketones (MEK, Acetone) which causes it to swell and Dichloromethane which also cause swelling and break down.
  • Avoid prolonged exposure to Ozone and UV.
  • The stability of F28P is very stable due to cross-linked nature of polymer.
  • The material can be cut with a sharp craft knife to make various geometries to meet exact end-user requirements.

Acoustical specification

  • High insertion loss, approximated by 20 dB/cm/MHz.
  • High echo-reduction, greater than 42 dB at 1 MHz, to greater than 1 to 20 MHz.