US PATENT SUBCLASS 264 / 603
OUTSIDE OF MOLD SINTERING OR VITRIFYING OF SHAPED INORGANIC ARTICLE OR PREFORM

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264 /   HD   PLASTIC AND NONMETALLIC ARTICLE SHAPING OR TREATING: PROCESSES

603OUTSIDE OF MOLD SINTERING OR VITRIFYING OF SHAPED INORGANIC ARTICLE OR PREFORM {30}
604  DF  .~> Applying hot isostatic fluid pressure to preform using surrounding liquid (e.g., molten glass, melted tin, etc.) or fluid pressure-transmitting deformable sheath (e.g., metal foil, etc.)
605  DF  .~> Particular or specific manner of positioning, arranging, or conveying of plural articles or plural preforms (e.g., stacking, utilizing spacer, etc.) during sintering, vitrifying, or drying {3}
610  DF  .~> Simultaneously burning, vaporizing, or melting of embedded element or core to form nonrandom void
611  DF  .~> Of magnetic (e.g., ferrite, etc.) article or component {2}
614  DF  .~> Of electrical article or electrical component (i.e., not insulator, per se) {5}
621  DF  .~> Utilizing sol or gel {2}
624  DF  .~> Using organometallic or organosilicon intermediate {3}
628  DF  .~> Producing microporous article (e.g., filter, etc.)
629  DF  .~> Producing article having plural hollow channels {1}
632  DF  .~> Producing hollow article (e.g., tube, etc.) {4}
638  DF  .~> Shaping by extrusion (e.g., spinning, etc.) {1}
640  DF  .~> Producing fiber containing article or fiber {1}
642  DF  .~> Shaping or treating of multilayered, impregnated, or composite-structured article {2}
645  DF  .~> Introducing material under pressure into mold (e.g., injection molding, etc.)
646  DF  .~> Utilizing chemically reactive atmosphere other than air, per se, during sintering to convert precursor to ceramic material {2}
649  DF  .~> Utilizing exothermic reaction
650  DF  .~> Casting of film (e.g., sheet, tape, etc.)
651  DF  .~> Removal of liquid component or carrier through porous or absorbent mold surface (e.g., slip casting, etc.)
652  DF  .~> Sintering or vitrifying in a tunnel or channel kiln
653  DF  .~> Including plural heating steps {3}
667  DF  .~> Including specified molding pressure or controlling of molding pressure (e.g., cold isostatic pressing, hydrostatic pressure, etc.) {1}
669  DF  .~> Utilizing binder to add green strength to preform {1}
671  DF  .~> Particular or specific manner of positioning, arranging, or conveying of single article or preform (e.g., utilizing spacer, etc.) during sintering, vitrifying, or drying {2}
674  DF  .~> Involving specified composition of heating atmosphere, other than air {2}
677  DF  .~> Controlling or directing flow of heated gas or exhaust within heating chamber (e.g., sintering furnace, drying chamber, etc.) or against article
678  DF  .~> With article cutting, punching or grinding
679  DF  .~> Of clay containing material {1}
681  DF  .~> Producing metal oxide containing product
682  DF  .~> Producing silicon carbide containing product
683  DF  .~> Producing silicon nitride containing product

DEFINITION

Classification: 264/603

OUTSIDE OF MOLD SINTERING OR VITRIFYING OF SHAPED INORGANIC ARTICLE OR PREFORM:

(under the class definition) Processes for producing or treating inorganic shaped articles in which a self-sustaining shaped article or preform comprising inorganic materials or precursors thereof are fired outside of the mold at temperatures sufficiently high to cause said article or preform to become sintered or vitrified without substantial loss of original self-sustaining shape due to sagging or gravity.

(1) Note. Vitrification is a densification of inorganic ceramic material that results from firing at sufficient temperature to produce a progressive fusion of particles through the assistance of a viscous liquid silaceous-like bonding phase into a body having dense glass-like characteristics (e.g., hardness, brittleness, smoothness, etc.). As vitrification progresses, the proportion of glassy-like bond formed increases and apparent porosity of the substance decreases without appreciable slumping or sagging. Sintering is the coalescence of parts through solid state diffusion into a densified solid mass through heating, generally with fusion limited to only surface layer of each particle, such that some particulate identity remains. The partial melting or vitrification of inorganic materials in the mold is provided for in various subclasses below, such as subclasses 109+ or 332+.

(2) Note. The terms baking, burning, calcining, or firing recited in a patent is considered to read on either sintering or vitrifying and is included herein, unless disclosed as being for some other purpose or at a clearly too low or inadequate temperature to accomplish sintering or vitrifying. Baking, burning, calcining, or firing outside the mold of shaped articles to decompose binder or organometallic precursors is included hereinunder if other criteria of this

subclass definition are met. However, baking, burning, calcining, or firing, (a) to render a mass friable, (b) at a temperature only sufficient to drive out the moisture content, or (c) to volatilize organic material without decomposition would be excluded from subclasses 603+.

(3) Note. Articles formed by accretion from bulk having embedded therein a form to be removed during or after firing are considered to be self-sustaining bodies for the purpose of this subclass.

(4) Note. Hot isostatic pressing (i.e., HIP) relates to application of an equalized fluid pressure to all external sides or surfaces of an article. This is usually performed outside of a mold in a gaseous atmosphere at substantially elevated temperatures and pressures. Lacking an indication to the contrary, hot isostatic pressing per se of an article or preform will therefore be assumed to occur outside of a mold at a temperature sufficiently high to be proper for this subclass. Shaping by applying hot isostatic fluid pressure to a preform using surrounding liquid (e.g., molten glass coating, melted tin, etc.) or fluid pressure-transmitting deformable sheath (e.g., metal foil, etc.) will be considered to be outside a mold for purposes of this subclass. However, so-called "pseudoisostatic pressing" with loose particulate between solid pressing surfaces and preform will not be considered proper for this subclass.

(5) Note. See Lines With Other Classes, "Lines With the Chemical Classes" (8) of the class definition.

SEE OR SEARCH THIS CLASS, SUBCLASS: 0.5+, for shaping or treating of radioactive materials (e.g., sintering uranium oxide rods, etc.).

15, for processes of spheroidizing or rounding of solid particles.

16+, for shaping ceramic dental type articles.

29.1+, for processes which include a step of carbonizing by a firing operation which produces a product containing elemental carbon therein.

30, for processes of furnace lining or repair which may include a firing operation.

43+, for processes of forming pores in inorganic materials during vitrification or firing.

125+, for sintering or heat fusion of particles to autogenously bond while in a mold (e.g., hipping, etc.)

234+, for applied temperature change out of mold.

332, for fusing or melting inorganic materials, per se, in a

mold or employing a mold and see (5) Note above.

333+, for shaping inorganic settable hydraulic compositions under heat or pressure and see (5) Note above.

345+, for treating shaped or solid articles by a temperature change. 405+, for processes of firing, sintering, or vitrifying wherein wave energy or electric current is involved.

SEE OR SEARCH CLASS

65, Glass Manufacturing, appropriate subclasses for processes under the class definition which include glass fusing or vitrifying. A process directed to (a) heating a material within the scope of Class 65 to the molten state and forming a shaped preform therefrom, or (b) bulk depositing glass fibers into a mold surface and thereafter fusing the fibers to each other is classified in Class 65. See the definitions of Class 65, section III B, with particular reference to the line with this class 264 for processes. See also the search notes to Class 65,

17.3, 376, and 454; and see the class definitions in this class 264 for further delineation of the line with Class 65.

(1) Note. With regard to glass particle uniting, a recitation of placing of glass particles (i.e., other than glass fibers or mineral wool) in their final position in a mold, followed by autogenous uniting or sintering outside the mold in the configuration or shape imparted by said mold, will be classified in this Class 264; whether or not said particles are disclosed to maintain their individual identities to any degree. Class 264 takes processes directed to (a) shaping a mass of green siliceous material and subsequently firing or curing the material to set the material or (b) placing discrete siliceous particles (i.e., other than glass fibers or mineral wool) onto a mold surface which particles are heated on or subsequent to contact with the surface to fuse the particles to each other.

(2) Note. Using a glass in a molten state as a fluid pressure transmitting media in hot isostatic pressing of shaped articles is acceptable in Class 264, if the glass is subsequently removed and is not part of the final pressed product.

75, Specialized Metallurgical Processes, Compositions For Use Therein, Consolidated Metal Powder Compositions etc., particularly

751+, for processes of heat treating (e.g., calcinating, fusing, indurating, roasting, sintering, vaporizing, etc.) to preparing consolidated shaped metalliferous charges (e.g., ore, tailings, flue dust, fluxes, etc.) or metalliferous treating agents amenable to Class 75 or Class 420 refining or

alloying operation.

156, Adhesive Bonding and Miscellaneous Chemical Manufacture,

89.11+, for vitrification or firing of a ceramic material when combined with a laminating step joining preforms.

419, Powder Metallurgy Processes, 10+, for processes of making articles from particulate material containing a metal and nonmetal involving pressure and heat (e.g., sintering, etc.).

(1) Note. Combined operations involving sintering particulate metal and particulate ceramic is proper for Class 419.

(2) Note. If, after Class 419 consolidation of metal particles, subsequent processing eliminates completely all free metal from the consolidated shaped particulate free metal by total conversion thereof to a metal compound or composition (e.g., metal oxide, metal nitride, etc.) as a result of firing or sintering outside of the mold under reactive conditions, placement is to be considered proper in this section of Class 264.

427, Coating Processes, for processes including the combination of (a) firing and coating, or (b) nominal molding, significant coating, and firing; regardless of the sequence of the respective steps. However, combinations of (a) significant molding, firing, and coating, or (b) nominal shaping and nominal coating are classified in Class 264;regardless of the sequence of the respective steps. See this class

129, Note (1), for a discussion of shaping and coating combinations.

(1) Note. When sintering or firing of a coated or impregnated fibrous material results in decomposition of the fibrous material which acts as a shaping surface and production of a noncoated or nonimpregnated shaped product, the process will be considered proper for Class 264.

432, Heating,

6, for a residual heating process including a step of stacking or aligning the objects to be heated and subclasses 258+ for means for supporting ceramic work during heating; (i.e., kiln furniture).

501, Compositions: Ceramic, appropriate subclass for ceramic compositions, per se, and processes of preparing such compositions.

(1) Note. When nominal molding of a Class 501 composition

is involved, placement in Class 501 is proper if limited to the conditions set forth in any one of the following situations: (a) No conditions are specified. (b) Firing for a specified time at a specified temperature (e.g., firing for 10 minutes at 1000 deg.F, etc.). (c) Blending or mixing of ingredients of said composition during or prior to the molding step and a chemical reaction present.

(2) Note. When molding of a Class 501 composition is involved, Class 264 is proper if any one of the following situations are present: (a) Significant molding. (b) Nominal molding and specifying firing or sintering temperature without specifying time of heating. (c) Nominal molding and raising to specified temperature in a specified time (e.g., raising to 1000 deg. F in 10 minutes, etc.). (d) Nominal molding and plural heating steps during or after molding (e.g., ramping in stages, etc.). (e) Nominal molding, firing and controlled cooling. (f) Nominal molding and specifying pressure. (g) Nominal molding and blending or mixing ceramic with a temporary binder and firing which decomposes the binder. (3) Note. When there is any doubt concerning placement between Class 501 and Class 264 concerning nominal molding, resulting from variations not addressed by the above notes (1) or (2), original placement will go to Class 264 with a mandatory cross-reference to Class 501.

(4) Note. When there is (a) a process claim present that is proper for Class 264 and (b) a product claim classifiable as Class 501 composition expressed in terms of starting material, placement of original goes to Class 264. However, when there is (a) a process claim present that is proper for Class 264 and (b) a product claim classifiable as a Class 501 composition expressed in terms of a final processed state (e.g., "sintered" composition, etc.), placement of original goes to Class 501.

588, Hazardous or Toxic Waste Destruction or Containment,

252+, for the use of vitrification in the treatment of hazardous or toxic waste for purposes of containment.