Gypsum panels and methods
AssigneeUnited States Gypsum Company
InventorEvan Vincent Rohlf
Life of this patent
Estimating the term…
Abstract
Provided are wallboards in which gypsum core is adhered to a paper cover sheet with an adhesive. Wallboards with laminated paper cover sheets in which an inner water-absorbent cover sheet is adhered to the outer paper cover sheet are provided as well. Methods for making these wallboards are provided as well.
Claims20
A wallboard panel comprising a gypsum core sandwiched between two paper cover sheets, a facer paper cover sheet and a backer cover sheet, each paper cover sheet in contact with and covering the gypsum core,
- wherein each paper cover sheet has a surface proximate to the gypsum core, the bond side of the paper cover sheet, and
- wherein the bond side of at least one paper cover sheet is coated with an adhesive selected from the group consisting of polyacrylate, polyvinyl acetate, polyvinyl acetate and borax, polyurethane, and any combination thereof.
A wallboard panel comprising a gypsum core and at least one laminated paper cover sheet in contact with and covering the gypsum core,
- wherein the laminated paper cover sheet comprises an inner paper sheet, an adhesive layer, and outer paper sheet, the inner paper sheet being in contact with the gypsum core on one surface and the inner paper sheet being in contact with the adhesive layer on the other surface,
- wherein the outer paper sheet is applied over the adhesive layer, and wherein the second adhesive layer is sandwiched between the inner paper sheet and outer paper sheet, and
- wherein the adhesive layer binds the inner paper sheet and outer paper sheet together.
A method of making a wallboard panel, the method comprising:
- Applying a coating to the bond side of a first paper cover sheet, wherein the coating comprises a compound selected from the group consisting of an acrylic resin, PVA resin, PVA resin and borax, polyurethane resin and any mixture thereof;
- Depositing a gypsum slurry over the coated bond side of the paper cover sheet while the coating has not fully cured;
- Covering the gypsum slurry with a second paper cover sheet;
- and
- Allowing the gypsum slurry to set and the coating to cure.
A method of making a laminated wallboard panel, the method comprising:
- Binding water-absorbent paper with the water absorption value in the range from 30 g/M2 to 200 g/M2 as measured by the Cobb test (TAPPI T 441) with an adhesive selected from the group consisting of an acrylic resin, PVA resin, PVA resin and borax, polyurethane resin and any mixture thereof to a paper cover sheet and thereby creating a laminated paper cover sheet;
- Depositing a gypsum slurry over the water absorbent paper of the laminated paper cover sheet;
- and
- Applying a second paper cover sheet over the gypsum slurry.
Dependencies are inferred from the claim text.