Method of manufacture of glass reinforced gypsum board and apparatus therefor

• US 6,878,321 B2
• Filed: 11/30/2001
• Issued: 04/12/2005
• Est. Priority Date: 06/06/2001
• Status: Expired due to Term

• Current Assignee: Bpb Placo (Compagnie De Saint-Gobain)
• Original Assignee: Bpb Placo (Compagnie De Saint-Gobain)
• Inventors: Sanders, Christopher J., Hauber, Robert J., Hennis, Mark E., Fahey, Michael P.
• Primary Examiner(s): Colaianni, Michael P.
• Assistant Examiner(s): Poe, Michael I.
• Application Number:
  US09/997,446
• Publication Number:
  US 20020187298A1
• Time in Patent Office: 1,229 Days
• Field of Search: 156/40, 156/41, 156/45, 156/202, 156/216, 156/221, 156/280, 264/129, 264/255, 264/256, 264/261, 264/295, 264/339
• US Class Current: 264/129
• CPC Class Codes: B28B 11/0845 for smoothing
• CPC Class Codes: B28B 19/0092 to webs, sheets or the like, e.g. of paper, cardboard
• CPC Class Codes: B32B 13/02 with fibres or particles being present as additives in the layer
• CPC Class Codes: B32B 2260/021 Fibrous or filamentary layer layers of natural mineral fibres or particles being impregnated in a plastic substance B32B19/02
• CPC Class Codes: B32B 2260/044 Water-setting substance, e.g. concrete, plaster
• CPC Class Codes: B32B 2607/00 Walls, panels
• CPC Class Codes: E04C 2/043 of plaster E04C2/049 takes precedence
• CPC Class Codes: Y10T 156/1011 Overedge bending or overedge folding
• CPC Class Codes: Y10T 156/1034 Overedge bending of lamina about edges of sheetlike base
• CPC Class Codes: Y10T 156/1043 Subsequent to assembly
• CPC Class Codes: Y10T 428/22 Nonparticulate element embedded or inlaid in substrate and visible
• CPC Class Codes: Y10T 428/23 Sheet including cover or casing
• CPC Class Codes: Y10T 428/232 Encased layer derived from inorganic settable ingredient
• CPC Class Codes: Y10T 428/237 Noninterengaged fibered material encased [e.g., mat, batt, etc.]
• CPC Class Codes: Y10T 428/239 Complete cover or casing

Abstract

Gypsum board having inorganic fiber, preferably glass fiber, preferably glass fiber, includes providing face sheets which have been completely impregnated with a gypsum slurry so as to penetrate through said random interstices between the inorganic fibers and to thereby cover the board surfaces with gypsum slurry. The gypsum board product is formed by passing the wet gypsum board through a board forming station having double forming plates, an upper forming plate having at least a portion thereof being set at a predetermined angle relative to a lower forming plate and having a separation between the forming plates defining a predetermined dimension substantially equal to the desired thickness of the manufactured gypsum board product. The method provides a multilayer gypsum board having a polymeric compound added to unset gypsum so as to provide a gypsum board ready for finishing.

Claims

1. A method of manufacture of gypsum board having inorganic fiber face sheets, comprising the steps of:

providing a first gypsum slurry having a first consistency;

applying a predetermined amount of said first gypsum slurry onto at least a first continuous sheet, said sheet including randomly aligned, inorganic fibers having random interstices between said fibers;

passing said first continuous inorganic fiber sheet through a gypsum application station, said station including two applicator wheels for passing the inorganic fiber sheet therethrough, so as to cause the first gypsum slurry having a first consistency to penetrate through said random interstices between the inorganic fibers and to thereby coat both top and bottom surfaces of said first inorganic fiber sheet with said gypsum slurry having a first consistency;

depositing a second gypsum slurry having a second consistency on said first inorganic fiber sheet and causing said second gypsum slurry to be essentially evenly distributed over an upwardly facing top surface of said first inorganic fiber sheet;

applying a third gypsum slurry having a third consistency to a second of said at least one continuous, inorganic, fiber sheets, said second inorganic fiber sheet having random interstices between the fibers and causing said third gypsum slurry to penetrate essentially completely through said random interstices and to thereby coat both top and bottom surfaces of said second inorganic fiber sheet with said third gypsum slurry;

applying said second inorganic fiber sheet onto the second gypsum slurry thereby sheathing said second gypsum slurry within said first and second inorganic fiber sheets to form a wet gypsum board; and

forming said gypsum board product by passing said wet gypsum board through a board forming station having a lower forming plate and an upper forming plate, said upper forming plate having at least a portion thereof being set at a predetermined angle to said lower forming plate, the separation between said lower forming plate and said portion of said upper forming plate defining a predetermined dimension substantially equal to the desired thickness of the manufactured gypsum board product.

2. The method of manufacture of gypsum board according to claim 1 wherein said step of providing said first gypsum slurry further comprises providing said first gypsum slurry having a slurry consistency which is substantially denser relative to said second gypsum slurry consistency.

3. The method of manufacture of gypsum board according to claim 1 wherein said step of applying said third gypsum slurry further comprises applying a third gypsum slurry having a third gypsum slurry consistency which is substantially identical to said first gypsum slurry consistency.

4. The method of manufacture of gypsum board according to claim 1 wherein said steps of applying said first and third gypsum slurries to said first and second inorganic fiber sheets further comprise obtaining said first and third gypsum slurries from an identical gypsum slurry supply.

5. The method of manufacture of gypsum board according to claim 1, wherein said inorganic fiber of said first and second fiber sheets further comprises a glass fiber.

6. The method of manufacture of gypsum board according to claim 1 further comprising a step for folding the lateral edges of said first continuous inorganic fiber sheet over said second gypsum slurry prior to said step of applying said second inorganic fiber sheet onto the second gypsum slurry.

7. The method of manufacture of gypsum board according to claim 1 wherein said step of passing said first continuous inorganic fiber sheet through a gypsum application station further comprises rotating said two applicator wheels in the forward direction relative to the motion of said inorganic fiber sheet through said gypsum application station.

8. The method of manufacture of gypsum board according to claim 1 wherein said step of passing said first continuous inorganic fiber sheet through a gypsum application station further comprises rotating said two applicator wheels in the reverse direction relative to the direction of movement of said first inorganic fiber sheet through said gypsum application station.

9. The method of manufacture of gypsum board according to claim 1 wherein said step of depositing said second gypsum slurry on said first continuous inorganic fiber sheet is followed by dispersing said unset second gypsum slurry over said first continuous inorganic fiber sheet so as to uniformly cover said unset second gypsum slurry over an upwardly facing surface of said first inorganic fiber sheet.

10. The method of manufacture of gypsum board according to claim 1 wherein said step of passing said first continuous inorganic fiber sheet through a gypsum application station further comprises passing said first continuous inorganic fiber sheet through two applicator wheels, at least one of said applicator wheels including a thin film polymer coating on the surface thereof.

11. The method of manufacture of gypsum board according to claim 1 wherein said step of passing said first continuous inorganic fiber sheet through a gypsum application station further comprises passing said first continuous inorganic fiber sheet through two applicator wheels, at least one of said applicator wheels including a thin film polymer coating on the surface thereof, said thin film polymer coating further comprising at least one compound selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene fluorocarbon and fluorinated ethylene propylene.

12. The method of manufacture of gypsum board according to claim 1 further comprising passing the wet gypsum board through an edger bar assembly, after the board forming step, so as to form the lateral edges of said gypsum board product and to complete the smoothing of the upper surface of said gypsum board product.

13. The method of manufacture of gypsum board according to claim 1 further comprising, after the board forming step, a step of applying an acrylic coating over the gypsum slurry containing said polymer layer on said gypsum board surface, and then curing said polymer layer.

14. The A method of manufacture of gypsum board having inorganic fiber face sheets, comprising the steps of:

providing a first gypsum slurry having a first consistency;

introducing a polymeric compound additive to said first gypsum slurry;

applying a predetermined amount of said first gypsum slurry onto at least a first continuous sheet, said sheet including randomly aligned, inorganic fibers having random interstices between said fibers;

passing said first continuous inorganic fiber sheet through a gypsum application station, said station including two applicator wheels for passing the inorganic fiber sheet therethrough, so as to cause the first gypsum slurry having a first consistency to penetrate through said random interstices between the inorganic fibers and to thereby coat both to and bottom surfaces of said first inorganic fiber sheet with said gypsum slurry having a first consistency to produce a gypsum polymer layer;

depositing a second gypsum slurry having a second consistency on said first inorganic fiber sheet and causing said second gypsum slurry to be essentially evenly distributed over an upwardly facing top surface of said first inorganic fiber sheet;

applying a third gypsum slurry having a third consistency to a second of said at least one continuous, inorganic, fiber sheets, said second inorganic fiber sheet having random interstices between the fibers and causing said third gypsum slurry to penetrate essentially completely through said random interstices and to thereby coat both top and bottom surfaces of said second inorganic fiber sheet with said third gypsum slurry;

applying said second inorganic fiber sheet onto the second gypsum slur thereby sheathing said second gypsum slurry within said first and second inorganic fiber sheets to form a wet gypsum board; and

forming said gypsum board product by passing said wet gypsum board through a board forming station having a lower forming elate and an upper forming plate, said upper forming plate having at least a portion thereof being set at a predetermined angle to said lower forming plate, the separation between said lower forming plate and said portion of said upper forming plate defining a predetermined dimension substantially equal to the desired thickness of the manufactured gypsum board product.

15. The method of manufacture of gypsum board according to claim 14 further comprising a steps, following the board forming step, of applying an acrylic coating onto at least one of said lower and upper surfaces of said gypsum board and thereby causing said acrylic coating to bond with said polymeric additive in said first gypsum slurry.

16. The method of manufacture of gypsum board according to claim 14 wherein said additive step includes adding to said unset gypsum at least one polymeric compound selected from a group consisting of polyacrylamide, polymethylacrylamide, polyvinyidene chloride (PVDC), polyamide, polyvinylchloride (PVC), polyethylene, cellulose acetate, Nitrile Rubber, polycarbonate, polypropylene, polystyrene, styrene, butadiene, styrene butadiene copolymer, polychloroprene, polytetrafluorethylene, tetrafluoroethylene fluorocarbon, fluorinated ethylene propylene, natural rubber, poly (2,6 dimethyl pentene oxide), poly 4, methyl pentene-1 and polydimethyl siloxane.

17. The method of manufacture of gypsum board according to claim 14 further comprising, after the board forming step, a step of applying an acrylic coating over the gypsum slurry containing said polymer layer on said gypsum board surface, and then curing said polymer layer.

18. The method of manufacture of gypsum board according to claim 17 wherein said acrylic coating is applied by flood coating.

19. The method of manufacture of gypsum board according to claim 14 wherein said additive step includes adding to said unset gypsum at least one polymeric compound selected from a group consisting of polyacrylamide, polymethylacrylamide, polyvinyidene chloride (PVDC), polyamide, polyvinylchloride (PVC), polyethylene, cellulose acetate, Nitrile Rubber, polycarbonate, polypropylene, polystyrene, styrene, butadiene, styrene butadiene copolymer, polychloroprene, polytetrafluorethylene, tetrafluoroethylene fluorocarbon, fluorinated ethylene propylene, natural rubber, poly (2,6 dimethyl pentene oxide), poly 4, methyl pentene-1 and polydimethyl siloxane.

20. The method of manufacture of gypsum board according to claim 19 further comprising, after the board forming step, a step of applying an acrylic coating over the gypsum slurry containing said polymer layer on said gypsum board surface, and then curing said polymer layer.