Disclosed are product (e.g., panels), slurry, and methods relating to an uncooked starch having a mid-range peak viscosity (i.e., from about 120 Brabender Units to about 900 Brabender Units).

Disclosed is an acid-modified flour and a method of making the acid-modified flour. The acid-modified flour is desirably prepared using a dry milling process. A starting flour is combined with a strong acid to form a mixture. The mixture is heated. A neutralizer is added to increase the pH of the mixture. If desired, the mixture can be dried and any agglomerates can be removed. The acid-modified flour can be used as a binder in a slurry for preparing one or more gypsum layers in a gypsum board.

In the present disclosure, a gypsum panel is disclosed. The gypsum panel comprises a gypsum core having a first gypsum layer surface and a second gypsum layer surface opposite the first gypsum layer surface and a fluted layer having a first fluted layer surface and a second fluted layer surface opposite the first fluted layer surface wherein the first fluted layer surface facing the first gypsum layer surface. The present disclosure is also directed to a method of forming the aforementioned gypsum panel.

Disclosed are a composite gypsum board and a method of preparing composite gypsum board. The board contains set gypsum layers sandwiched between two cover sheets. The set gypsum layers are formed from at least stucco and water. The set gypsum layers include a board core and one or more skim coat layers. The set gypsum core makes up a substantial thickness (e.g., at least about 90%, at least about 92%, at least about 95%, or at least about 97%) of the total thickness of all the gypsum layers. A first skim coat layer is included on one side of the core, facing a first (face) cover sheet. A second skim coat layer is included on the other side of the core, facing a second (back) cover sheet. At least the second skim layer is formed from a slurry that contains starch. The stucco material generally includes a high salt impurity content, for example, when the stucco is calcined from certain sources of low-quality synthetic gypsum. For example, in some embodiments, the salts are chloride salts, e.g., sodium chloride (NaCl), potassium chloride (KCl), magnesium chloride (MgCl.sub.2), and/or calcium chloride (CaCl.sub.2).

Disclosed are product (e.g., panels), slurry, and methods relating to an uncooked starch having a mid-range peak viscosity (i.e., from about 120 Brabender Units to about 900 Brabender Units).

An impact resistant exterior sheathing gypsum building panel with an integrated impact resistant woven mesh which protects against impact from projectiles such as those conveyed by hurricane force winds is provided. Methods for manufacturing these exterior sheathing gypsum building panels with an integrated impact resistant woven mesh are also provided. An exterior sheathing system employing the exterior sheathing cementitious building panel is provided.

The present invention is directed to a gypsum panel and a method of making a gypsum panel. The gypsum panel comprises a gypsum core and a facing material. The gypsum core includes gypsum, a foaming agent, and optionally starch in an amount of less than 4 wt. % based on the weight of gypsum. The gypsum core includes air voids having an average void size of 50 microns or more. The gypsum panel has a density of 33 pcf or less, a weight of 1,800 lbs/MSF or less, and an NRC value of 0.2 or more.

A method to make an ultra-stable structural laminate of a cementitious material with a nano-molecular veneer and a foam component catalytically reacted into an expanded closed cell foam having a thickness from .sup.th inch to 8 inches, a density from 1.5 pounds/cubic foot to 3 pounds/cubic foot that inter-engages the cementitious material forming a matrix creating the ultra-stable structural laminate with fire resistance; a lateral nail pull strength from 44 pounds to 300 pounds of force; an insulation R value from 1 to 40; a resistance to seismic impact for earthquakes over 3.1 on the Richter Scale; a break point from 7 lbs/inch to 100 lbs/inch; and a resistance to wind shear equivalent to a 15 mph downburst.

A building with ultra-stable cementitious material with nano-molecular veneer has 29 wt % to 40 wt % of a magnesium oxide dry powder containing 80 wt % to 98 wt % of magnesium oxide based on a final total weight of the cementitious material, 14 wt % to 18 wt % of a magnesium chloride dissolved in water and reacting to form a liquid suspension, a phosphorus-containing material, and wherein the mixture forms a liquid suspension that reacts into an amorphous phase cementitious material, wherein a portion of the amorphous phase cementitious material grows a plurality of crystals. The plurality of crystals are encapsulated by the amorphous phase cementitious material forming a nano-molecular veneer and a wall material that is affixed to a frame of a building.

A plasterboard comprises a gypsum matrix having fibres embedded therein. The plasterboard optionally has a backing lamina attached to one of the faces thereof. The gypsum matrix of the plasterboard optionally comprises a polymeric additive.