A knitted spacer fabric has a tightly knitted bottom layer, a more loosely knitted upper layer and linking fibres extending across the space between the lower and upper faces. Settable material, e.g. cement, is introduced into the space between the upper and lower faces and can be caused to set by the addition of a liquid, e.g. water. Until set, the fabric is flexible and can be shaped but after the material in space has set, the fabric is rigid and can be used as a structural element in a wide range of situations. The bottom layer has an extension that extends beyond the upper face and is connected to the upper face by elastic connecting fibres that draw the extension towards the other face, thereby at least partly closing the space at the edge of the cloth and preventing the settable material from spilling out. In addition, the packing of the settable material and maximum space between the faces are such that only a predetermined amount of liquid can be accommodated within the space and that amount is matched to the water required to set the cement.

One variation of a method for fabricating a dermal heatsink includes: fabricating a substrate defining an interior surface, an exterior surface opposite the interior surface, and an open network of pores extending between the interior surface and the exterior surface; activating surfaces of the substrate and walls of the open network of pores; applying a coating over the substrate to form a heatsink, the coating comprising a porous, hydrophilic material and defining a void network; removing an excess of the coating from the substrate to clear blockages within the open network of pores by the coating; hydrating the heatsink during a curing period; heating the heatsink during the curing period to increase porosity of the coating applied over surfaces of the substrate; and rinsing the heatsink with an acid to decarbonate the coating along walls of the open network of pores in the substrate.

This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.

Disclosed herein are low density fiber cement articles, such as fiber cement building panels and sheets, comprised of multiple overlaying fiber cement substrate layers having small and uniform entrained air pockets and low density fillers distributed throughout. The combination of entrained air pockets and low density fillers provide a low density fiber cement matrix with physical and mechanical properties similar to comparable low density fiber cement matrix without entrained air pockets.

Disclosed herein are low density fiber cement articles, such as fiber cement building panels and sheets, comprised of multiple overlaying fiber cement substrate layers having small and uniform entrained air pockets distributed throughout. Also disclosed herein are air entrainment systems and methods for manufacturing aerated low density fiber cement panels or sheets with consistent air void content and uniform air void distribution. Also disclosed herein are air entrainment technologies adapted to work in conjunction with the Hatschek process to produce aerated fiber cement articles having controlled air void content and distribution.

A gypsum board comprises a cover sheet and a gypsum layer disposed on the cover sheet. The gypsum layer comprises the reaction product of an isocyanate, water, and stucco. The isocyanate increases the moisture resistance of the gypsum board. A method of manufacturing the gypsum board comprises the steps of combining the isocyanate, the water, and the stucco to form a slurry, and applying the slurry to a cover sheet to form the gypsum layer on the cover sheet.

This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.

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.

A reduced weight, reduced density gypsum panel that includes high expansion vermiculite with fire resistance capabilities that are at least comparable to (if not better than) commercial fire rated gypsum panels with a much greater gypsum content, weight and density.

One variation of a method for fabricating a dermal heatsink includes: fabricating a substrate defining an interior surface, an exterior surface opposite the interior surface, and an open network of pores extending between the interior surface and the exterior surface; activating surfaces of the substrate and walls of the open network of pores; applying a coating over the substrate to form a heatsink, the coating comprising a porous, hydrophilic material and defining a void network; removing an excess of the coating from the substrate to clear blockages within the open network of pores by the coating; hydrating the heatsink during a curing period; heating the heatsink during the curing period to increase porosity of the coating applied over surfaces of the substrate; and rinsing the heatsink with an acid to decarbonate the coating along walls of the open network of pores in the substrate.