Abstract: A process for preparing calcined gypsum (stucco) which comprises treating a mass of calcined gypsum by adding, with thorough blending, small portions of water (about 1-10% by weight) to the calcined gypsum, allowing it to heal, and grinding the healed stucco to recapture the rate of strength development and the ultimate strength which are adversely affected by the water addition. The principal advantage provided by the addition of small portions of water is a reduction in water demand which is retained despite the grinding and optional drying of the healed stucco. If the treated calcined gypsum is not used shortly after the healing procedure, it should be dried to provide storage stability. The reduced water demand is particularly useful in gypsum board manufacture.

Abstract: A reinforced gypsum board having glass fibers concentrated in the portions of the rehydrated stucco immediately below the surfaces of the board, these portions being further defined by a density that is substantially greater than that of the interior portion of the board.

Abstract: A composition comprising an aqueous suspension of a polymeric adhesive composition such as a latex or emulsion is coated on a paper cover sheet in a selective pattern such that the composition is disposed only at limited areas of the bond liner surface, and wherein substantial areas of the bond liner surface are free of coating; the coated paper, either in the wet stage or after drying being used in the form of paper cover sheets to form gypsum wallboard by applying an aqueous slurry of calcined gypsum, which may be free of any additional adhesive material, to the coated surface and setting the gypsum, resulting in a gypsum wallboard having excellent adhesion between the paper cover sheets and the gypsum core.

Abstract: A plaster composition containing an agent for reducing the amount of water necessary in forming a pourable aqueous calcined gypsum slurry, the agent comprising a high potassium salt of a condensation product of naphthalene and sulfonic acid having a molecular weight between about 300 and 3,000. Aqueous plaster slurries containing the agent are pourable, moldable and castable with much less excess water than ordinarily required, resulting in dried cast products of increased strength and other physical property benefits.

Abstract: A resilient sheet metal runner for attaching wallboard to a supporting structure comprising a base attaching flange having a resilient web coextensive therewith and integral with a longitudinal edge thereof with a support portion integral with an opposite edge of the resilient web and a stop flange integral with the opposite edge of the support portion. The base flange is disposed in a first plane, the flexible web is disposed in a second plane at an obtuse angle to that of the base flange and with respect to a third plane represented by the support portion. The stop flange extends at an obtuse angle toward the first plane in a fourth plane which it occupies but is of less width than the resilient web so that it does not extend into the first plane.

Abstract: A composition for accelerating the setting of an aqueous calcined gypsum slurry, the composition comprising finely ground calcium sulfate dihydrate and a lignosulfonate. The composition, when added to an aqueous calcined gypsum slurry, accelerates the setting process and shortens the set time period as determined by the temperature rise set test procedure. The composition is useful for making gypsum wallboard.

Abstract: A calcining apparatus comprising a kettle, a heating jacket surrounding the kettle defining a heating chamber, vertical baffles dividing said heating chamber into a plurality of chambers, and a plurality of horizontally disposed heating flues communicating with said chambers defining a path whereby the heating gas provided for heating said apparatus makes at least two horizontal passes through said kettle before being exhausted, the calcining apparatus being adaptable for calcining material such as gypsum in either a continuous or batch process.

Abstract: An atachment system, and attachment clip therefor, is disclosed for attaching panel engaging ceiling runners, positioned either parallel or perpendicular, to air distribution bar structures and inverted-T runner ceiling supporting structures.

Abstract: A metal stud for constructing a fire-rated wall and the wall structure formed of a plurality of studs mounted in runners and having at least a pair of spaced-apart layers of wallboard panels with adjacent panels in abutting relationship, the stud being formed of an integral piece of sheet metal and comprising a single layer web having a first plurality of oppositely directed flange means at one edge thereof and a second pair of oppositely directed flange means connected to the web means at the other end thereof and spaced-apart from the first pair of flange means a sufficient distance to provide a pair of oppositely directed channels receiving the edges of adjacent panels of a single layer, and means extending away from the second pair of oppositely directed flange means and being connected to and supporting a panel spaced apart from the first and second pairs of flange means and adapted to have the wallboard panels of a second layer affixed thereto in parallel spaced-apart relationship with regard to the fir

Abstract: Porous gypsum granules are produced by adding powdered plaster to a stable aqueous foam and agitating the foam until granules of desired size are formed. Agitation is terminated before the foam collapses, but when the foam has subsequently collapsed the damp granules are recovered and dried. The product granules have a generally spheroidal shape mainly in the size range 0.25 to 2 mm, with a fine compact outer surface layer and a coarser interior with voids which confer high absorbency. These can be used as carriers for active materials such as herbicides or insecticides for agricultural or horticultural purposes or as fillers for plastics. Apparatus for continuously mixing fluid materials and suitable for use with foam and gypsum consists of a trough-shaped conveyor with a series of rotary agitators spaced along it.

Abstract: A hollow wall partition assembly is disclosed which comprises a flanged ceiling rail, two opposing spaced apart rows of wall panels, snap-on trim pieces engaging grooves on the ceiling rail whereby the snap-on trim pieces conceal exposed unfinished portions of the ceiling rail. The partition assembly includes a snap-on glazing cover for window framing which is engageable with the assembled ceiling rail and snap-on trim pieces. A mullion and jamb attachment clip is provided for attaching door frame jambs and vertical mullions to the assembled ceiling rail and snap-on trim pieces.

Abstract: An improved process for forming cast articles of plaster reinforced with fibers is disclosed wherein low consistency plaster slurries that include a fluidizing agent and fibrous reinforcing materials are co-sprayed onto a sectionalized casting bed having a flexible membrane section connecting rigid sheet forming bed portions; allowed to stand in a horizontal position through initial stiffening; and then before the slurry has set, the sectionalized casting bed is reformed so as to produce a contoured shape to the gypsum cement sheet.

Abstract: A pallet comprising a generally flat top sheet and a generally flat bottom sheet spaced from the top sheet. A plurality of sills constructed from elongate generally flat rehydrated gypsum strips are sandwiched between the top and bottom sheets. A water-impervious cover is closely positioned over the sheets and over the edges of the sills.

Abstract: This invention pertains to an integral one piece corner trim member for an outside corner of a building structure or interior partition wherein the trim piece comprises an extruded section formed from a suitable vinyl material and having an integral barb at the inner side thereof to hold the corner piece in position on the building structure until it is fixedly secured to the building walls.

Abstract: Profiles may be extruded directly from powdered ABS or other similar thermoplastic materials without pelletizing the feed material, by compounding under dry air flush conditions; maintaining dry air atmosphere conditions on the compounded materials until charged into the extruder; and providing vacuum venting in the decompression zone of the extruder, with optional condensation inducement and entrapment in the vent. Method and apparatus are disclosed.

Abstract: A specially prepared paper bond liner, gypsum wallboard, and gypsum wallboard process which bonds the liner to the core by an adhesive confined to the paper-core interface, the adhesive comprising certain starches placed on the bond liner in their raw state.

Abstract: A carpet stretcher or kicker operable by engagement with the knee of an operator, the carpet stretcher or handle having a shank, a head with carpet-engaging pins adjustably mounted therein positioned at one end of the shank, and a kicking plate having a padded cover at the other end, the shank being formed of telescoping shank members which may be rotated ninety degrees with respect to each other for disengagement, moved longitudinally with respect to each other to obtain the desired shank length, and then rotated ninety degress with respect to the original relative position to lock the members axially with respect to each other.

Abstract: A composition comprising water, finely particulate gypsum and starch is coated on a paper cover sheet in a selective pattern such that the starch composition is disposed only at limited areas of the bond liner surface, and wherein substantial areas of the bond liner surface are free of the coating; the coated paper, either in the wet stage or after drying being used as paper cover sheets to form gypsum wallboard by applying an aqueous slurry of calcined gypsum, which may be free of starch, to the coated surface and setting the gypsum, resulting in a gypsum wallboard having excellent adhesion between the paper cover sheets and the gypsum core.

Abstract: A clip is disclosed for securing sound absorbing panels or the like to supporting structures. The clip has a wall plate, a projection extending outwardly from the wall plate and at least two securing members at the end of the projection opposite the wall plate, with the securing members each extending further in one direction from the projection than their extension from the projection in the opposing direction.A sound absorbing system is disclosed and includes a supporting structure, clips, as defined above, attached to the supporting structure, and sound absorbing panels attached to the clips. The sound absorbing panels comprise a sound absorbing panel with a frame extending around the exterior perimeter of the panel, and the frame has a plurality of openings for accepting the securing members. The securing members are placed into the openings to attach the sound absorbing panels to the supporting structure.

Abstract: A joint compound which is preferably asbestos-free, for use in finishing joints between wallboards, comprising a filler, a binder, and any two or all three of a water-holding agent; a slip-inducing colloid; and a non-swelling clay having sufficient pseudoplasticity to render the composition non-leveling.