US PATENT SUBCLASS 162 / 63
.~ Gas, vapor or mist contact

Current as of: June, 1999
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162 /   HD   PAPER MAKING AND FIBER LIBERATION

1  DF  PROCESSES OF CHEMICAL LIBERATION, RECOVERY OR PURIFICATION OF NATURAL CELLULOSE OR FIBROUS MATERIAL {33}
63.~ Gas, vapor or mist contact {4}
64  DF  .~.~> Sulfur dioxide
65  DF  .~.~> Oxygen, ozone or air
66  DF  .~.~> Chlorine containing material {1}
68  DF  .~.~> Steam only

DEFINITION

Classification: 162/63

(under subclass 1) Processes wherein the fibrous material is forcibly and directly contacted with a gas, vapor or mist during digestion or chemical treatment for some purpose other than drying.

(1) Note. Admission of a gas or vapor into a portion of a reaction vessel in which the fibers are immersed in a liquid is not sufficient basis for classification in this or indented subclasses unless it positively appears that there is direct contact with the fibrous material. Nor is the generation of a gas in situ by a chemical reaction of two liquids sufficient basis for classification in this group of subclasses.

(2) Note. The gas, vapor or mist may be nonreactive with the fibers.

SEE OR SEARCH THIS CLASS, SUBCLASS:

23, for processes of digestion including a mechanical

defibration in the presence of a gas under elevated temperatures and pressures.