DESIGN NEWS REPORT OPEN-PORE POLYURETHANE FOAM AND FELT
November 25, 1964
[DESIGN NEWS REPORT pamphlet page 1]
Good chemical and physical properties make the material well-suited to a variety of applications. These include air and liquid filtration, humidification, demisting, sound absorption and abrasive polishing and cleaning.
Open-pore polyurethane felt is a recently introduced, compressed variation of the standard foam material. The felt provides greater density, smaller pore sizes, finer textures and much higher mechanical strength. To date, primary applications of open-pore felt have been in the field of sound absorption, capillary conveyance of liquids and extremely fine particle filtration.
Porosity and texture
Open-pore foam is produced in a number of standard porosity grades. Rated in terms of pores per lineal inch (ppi), these range from 10 to 100 ppi. Tolerance on porosity is closely controlled and is generally + 5 ppi in most grades.
Texture of the open-pore foam ranges from coarse and abrasive in the 10 ppi grades to soft and downy in the 100 ppi grade. Void volume is constant at 97 percent for all grades. Density is also constant at a nominal 2 lb. per cu ft.
Porosity, density and texture of the open-pore felt depend on the porosity of the original standard foam and on the extent