A collection of documents disclosing the use of a material, usually covering or enclosing a device of the class, that have microscopic pores severely limiting the passage of solids or liquids through said materials.
(1) Note. This collection includes covers that permit the passage of air, but not the passage of an allergen such as dust, mites, and mite feces.
(2) Note. This collection includes covers that severely limit the rate of passage of vapors through the cover.
SEE OR SEARCH THIS CLASS, SUBCLASS:
482+, for bedclothing such as a pillow case, sheet, etc.
689, for a fluidized bed in which covers that are porous to gases, such as air, cover small fluidized beads.
699, for mattresses that have a waterproof or allergenproof outer surface.
