GYPSUM BOARD FROM GYPSUM HAVING HIGH LEVEL OF CHLORIDE SALT AND A PERFORATED SHEET AND METHODS ASSOCIATED THEREWITH

    公开(公告)号:US20200055277A1

    公开(公告)日:2020-02-20

    申请号:US16401675

    申请日:2019-05-02

    摘要: Gypsum boards formed from synthetic gypsum and other gypsum sources having high chloride salt concentrations. The gypsum boards may include a set gypsum board core layer between a front and back paper cover sheets. The back paper cover sheet has a plurality of perforations extending therethrough. Methods of making the gypsum boards, and a wall system for employing the gypsum boards, are also provided. The concentration of the chloride anion in aqueous gypsum slurry used to make the set gypsum board core layer and to perform the methods of the invention may range from about 500 ppm to about 3000 ppm, typically from about 500 ppm to about 2000 ppm per 1,000,000 parts by weight calcium sulfate hemihydrate, more typically from about 500 ppm to about 1500 ppm per 1,000,000 parts by weight calcium sulfate hemihydrate.

    SILOXANE POLYMERIZATION IN GYPSUM WALLBOARD
    2.
    发明申请

    公开(公告)号:US20200024191A1

    公开(公告)日:2020-01-23

    申请号:US16401658

    申请日:2019-05-02

    摘要: A method of making a gypsum board including: preparing an aqueous slurry including a mixture of: calcium sulfate hemihydrate, water at a weight ratio of water to calcium sulfate hemihydrate of 0.2:1 to 1.2:1, and on a dry basis per 100 parts by weight (pbw) calcium sulfate hemihydrate: 0.2 to 2 pbw siloxane, 0.01 to 2 pbw siloxane polymerization catalyst including magnesium oxide and optionally fly ash, and 0.01 to 0.2 pbw triethanolamine (TEOA); allowing the siloxane to polymerize to polysiloxane; and depositing the slurry on a first cover sheet and covering the slurry with a second cover sheet to shape the slurry, and allowing the shaped slurry to set to form the gypsum board. Also, disclosed is the gypsum board resulting from the method.

    FIRE RESISTANT GYPSUM BOARD AND RELATED METHODS

    公开(公告)号:US20210238096A1

    公开(公告)日:2021-08-05

    申请号:US17156258

    申请日:2021-01-22

    摘要: Disclosed are a composite gypsum board and a method of preparing composite gypsum board. The board contains a set gypsum core sandwiched between two cover sheets. The core is formed from a slurry containing stucco, water, and optional ingredients such as foaming agent, accelerator, retarder, polyphosphate, starch, and dispersant, and core intumescent material. The board also contains at least one skim coat and/or hard edges. A face skim coat layer can be included on one side of the core, facing a face cover sheet. A back skim coat layer can be included on the other side of the core, facing a back cover sheet. Hard edges are known in the art and can be formed, e.g., continuously from a stucco slurry for forming the face and/or back skim coats. Preferably, the back skim coat layer and/or the hard edges are formed from a slurry containing stucco, water, skim coat or edge intumescent material (which have the same desired characteristics), and other optional additives as desired. The skim coat or edge intumescent material can be composed of the same material as the core intumescent material, if desired, but the skim coat and/or edge intumescent material is present in a higher relative concentration in its respective slurry than the amount of core intumescent material in the core slurry. Examples of suitable intumescent materials include expandable vermiculite (e.g., No. 4 or No. 5 according to the US naming system, or combinations thereof), expandable graphite, perlite, or any combination thereof.

    ALUMINATE-ENHANCED TYPE I PORTLAND CEMENTS WITH SHORT SETTING TIMES AND CEMENT BOARDS PRODUCED THEREFROM

    公开(公告)号:US20200331802A1

    公开(公告)日:2020-10-22

    申请号:US16801083

    申请日:2020-02-25

    摘要: Aqueous cementitious slurries including predominantly Type I Portland cement containing an aluminate additive. The aluminate additive is an aluminate salt other than calcium aluminate or calcium sulfoaluminate, preferably sodium aluminate. Cementitious reactive powders of the slurry include the Type I Portland cement and 0.1-10 wt. % of the aluminate additive as an accelerator. The slurries may have a set time of about 10 minutes or less. Due to the short set time, the cementitious reactive powders may facilitate cement board fabrication by continuous manufacturing processes. Methods for making cement boards may include disposing the aqueous cementitious slurry including the cementitious reactive powders in a continuous layer, preferably upon a porous support, and setting the aqueous cementitious slurry with a set time of about 10 minutes or less.

    MULTI-LAYER GYPSUM BOARD AND RELATED METHODS AND SLURRIES

    公开(公告)号:US20190352232A1

    公开(公告)日:2019-11-21

    申请号:US16401899

    申请日:2019-05-02

    摘要: Disclosed is a composite gypsum board comprising a board core and a concentrated layer, as well as related methods of preparing board and slurries. The board core and the concentrated layer both are formed from water and stucco. The concentrated layer is designed to have higher density and/or nail pull than the core. The concentrated layer is further formed from one or more of starch thickener, cellulose, and/or copolymer containing polyacrylamide and acrylic acid. In some embodiments, the concentrated layer is formed from an enhancing additive to enhance strength therein, while the core is formed without using enhancing additive or less enhancing additive than used in forming the board core.