Lossy Foam Block Absorber (EHP-LFBCL)

Lossy Foam Block

Lossy Foam Block (LFB) is a flat multi-purpose absorber that can be readily customized for shapes to cover corner areas or positioning equipment.

ETS-Lindgren's Extra High Performance Lossy Foam Block Combustion LImiting (EHP-LFBCL) broadband absorber is part of a line of combustion limiting polyurethane absorber made from urethane foam impregnated with a dielectrically matched conductive carbon, and cut into blocks. LFB materials is a flate multi-purpose absorber typically used as a corner treatment or for covering positioning equipment and can be cut into any thickness and dimensions to suit the application. LFB absorber effectively reduces reflections between 30 MHz and 100 GHz. ETS-Lindgren guarantees its EHP series absorber to absorb 1/2 Watt per square inch without material damage.

Key Features
  • Reduces reflections between 30 MHz and 100 GHz
  • Absorbs 1/2 Watt per square inch
  • Customizable for thickness and dimensions for any application
Product Details
Product Features

To produce our polyurethane absorber material, ETS-Lindgren uses a unique two-step impregnation process to maximize carbon distribution uniformity achieving higher performance consistency and better fire resistance. Urethane foam block is first compressed and submerged in a mixture of dielectrically-matched conductive carbon suspended with a mixture of neoprene latex. The foam absorbs the carbon-neoprene mixture, permeating the foam cells and ensuring complete distribution. The second step utilizes a solution of fire retardant ingredients. This two-step process allows us to uniformly impregnate the absorber, giving rise to its consistent RF performance over a broad frequency band.

Non-Hygroscopic (Moisture-Resistant) Substrate

Traditionally, the most widely used fire-retardant salts are ammonium based compounds that are highly hygroscopic (strong tendency to absorb water molecules from ambient air humidity). Developments in chemical engineering have allowed ETS-Lindgren to utilize a non-hygroscopic, moisture-resistant substrate. ETS-Lindgren absorber experiences a mass increase of less than 3% when subjected to 95% relative humidity at 100 degrees Fahrenheit for at least 240 hours. This new fire-retardant formula also improves our absorber fire resistance with a lower level of fire retardant loading. The most critical aspect of the non-hygroscopic substrate is that the absorber performance is not adversely impacted by absorbed moisture from the surrounding air, which may affect overall system performance. This makes ETS-Lindgren chamber solutions preferred solutions when there are any doubts about the stability of the climatic conditions in the chamber or the parent facility.

Physical Specifications

Fire Retardancy

  • NRL Report 8093 (Tests 1, 2, and 3)
  • MIT Lincoln Laboratory Specification MS-8-21 (1, 2 and 3)
  • UL 94-5VA and UL 94-5VB
  • UL 94 HBF
  • DIN 4102 Class B-2
Electrical Specifications

Power Handling

0.5W per in (775W per m)

Product Options

With FlexSorb, you can enjoy the same excellent performance characteristics as our traditional absorbers, with the advantages of improved durability. FlexSorb is a special absorber treatment that allows an absorber to bend but not break. It's ideal for high traffic areas like chamber doorways and interior walls, or for tests that require an anechoic floor treatment. And, being that FlexSorb is also non-hygroscopic: its weight does not change in the presence of atmospheric moisture. 

As a baseline, FlexSorb coated absorber material is provided on all included Lossy Foam Block.