The present invention relates to a system and method for the production of gypsum board using starch pellets. In accordance with the present disclosure, the starch necessary for board formation is provided in the form of starch pellets. These pellets are mixed with a gypsum slurry in a mixer. The pellets are initially insoluble and do not dissolve. However, during subsequent drying stages, the pellets become soluble and dissolve into the gypsum phase. This both provides the desired starch component and also results in the formation of voids within the set gypsum.

A sound damping wallboard and methods of forming a sound damping wallboard are disclosed. The sound damping wallboard includes a gypsum layer having a first side with a first gypsum surface, a first encasing layer at least partially covering the first gypsum surface to form a first encasing layer portion, and a sound damping layer on the first side covering at least part of the first encasing layer portion.

A sound damping wallboard and methods of forming a sound damping wallboard are disclosed. The sound damping wallboard comprises a gypsum layer with a gypsum surface having an encasing layer. The encasing layer is partially removed to expose the gypsum surface and form a gypsum surface portion and a first encasing layer portion on the gypsum layer. A sound damping layer is applied to the gypsum layer to cover at least part of the gypsum surface portion and the encasing layer portion.

An electrically conductive sandwich panel (10) supplies at least one electrical device to be pushed into the panel. The sandwich panel (10) has two electrically conductive layers (13, 15) insulated from each other and a layer (11) formed by a board (12, 14) insulated from said electrical layers. The board has two sheets (111, 112) of cardboard enclosing an electrically insulating material, such as plaster. Connectors are used to connect the electrically conductive layers to a power supply. The panel may be screw-fastened on a support by means of suitable screws and may be fitted with a suitable electrical device. A punch tool facilitates pushing the electrical device into the 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).

An adhesive binder composition for adhering a paper sheet to a gypsum article with a gypsum layer having at least one paper sheet on a major surface thereof. The adhesive binder composition includes a polymeric adhesive and at least one surfactant. The adhesive binder composition resides at a boundary between the gypsum layer and the paper sheet.

An example plasterboard includes a layer of hardened plaster material having a first surface and an opposed second surface and a layer of molded material having a surface that faces away from the layer of hardened plaster material. The surface of the layer of molded material has one or more raised features. The plasterboard also includes a liner between the first surface of the layer of hardened plaster material and the layer of molded material. Other examples include a method of forming such plasterboards and a method for installing such plasterboards.

An example plasterboard includes a layer of hardened plaster having a first surface and an opposed second surface, a layer of polymer material having particles of one or more cementitiously-active substances mixed therein, and a liner between the first surface of the layer of hardened plaster and the layer of polymer material. Another example is a method of forming such a plasterboard. The method includes loading an extruder with the polymer material having the particles of one or more cementitiously active substances mixed therein, extruding the polymer material through a die to form the layer of polymer material on a surface of the liner, contacting with a layer of wet plaster material, the liner having the polymer material applied thereon such that the surface of the liner faces away from the wet plaster material, and drying the layer of wet plaster material to form the layer of hardened plaster.

An example plasterboard includes a layer of hardened plaster material having a first surface and an opposed second surface and a layer of molded material having a surface that faces away from the layer of hardened plaster material. The surface of the layer of molded material has one or more raised features. The plasterboard also includes a liner between the first surface of the layer of hardened plaster material and the layer of molded material. Other examples include a method of forming such plasterboards and a method for installing such plasterboards.

A sound damping wallboard and methods of forming a sound damping wallboard are disclosed. The sound damping wallboard includes a gypsum layer having a first side with a first gypsum surface, a first encasing layer at least partially covering the first gypsum surface to form a first encasing layer portion, and a sound damping layer on the first side covering at least part of the first encasing layer portion.