(under subclass 100) Processes including a step of forming pores or other type of open space in situ within a felted body during or subsequent to the felting operation, and products of such processes.
(1) Note. The pores are usually formed by introducing a gas under pressure to the interior of the felted body or by generating a gas in situ in such body.
SEE OR SEARCH THIS CLASS, SUBCLASS:
158+, particularly subclass 181 for formation of porous paper by the addition of a porous material thereto, e.g., expanded perlite.
SEE OR SEARCH CLASS
106, Compositions: Coating or Plastic,
601+, and 672+ for processes of making various types of coating or plastic compositions, including a step forming pores in situ in the composition. 501, Compositions: Ceramic,
39, and 80+ for pore-forming ceramic compositions.
521, Synthetic Resins or Natural Rubbers,
50+, for pore-forming, per se, in a synthetic resin composition when the composition in which the pores are formed is a synthetic resin.
