| abstract |
Molded filtration products, such as disposable face masks, are prepared by assembling at least one fibrous shaping layer and one fibrous filtration layer in face-to-face contact and subjecting the assembly to heat and molding pressure. Preferably the assembly comprises two shaping layers, one on each side of the filtration layer. The shaping layers in total weight no more than about 150 pounds per ream and contribute no more than about 20 percent of the total pressure drop through the filtration product. At least one of the shaping layers comprises fibers that can be bound together at points of fiber intersections by coalescence of binder material on the fibers. |