MEMBRANE-READY FIBROUS FACED GYPSUM PANELS, APPARATUS, AND METHODS
Membrane-ready fibrous faced gypsum panels, methods, and apparatus are provided. The panels include a first fibrous mat having a first surface and a second surface, a second fibrous mat having a first surface and a second surface, a gypsum core in contact with the second surfaces of the first and second fibrous mats, and a material coating that covers the first surface of the first fibrous mat and forms a substantially smooth outer surface.
1 . A method of making an unattached, membrane-ready, exterior gypsum panel, comprising:
depositing a gypsum slurry onto a surface of a first fibrous mat;
depositing a second fibrous mat onto a surface of the gypsum slurry opposite the first fibrous mat, such that a surface of the second fibrous mat contacts the gypsum slurry, to form a gypsum sandwich structure;
drying the gypsum sandwich structure;
applying an adhesive coating composition to a surface of the first fibrous mat opposite the gypsum slurry, such that the adhesive coating covers at least a portion of the surface of the first fibrous mat; and
drying the adhesive coating composition to form a material coating on the first fibrous mat and form a membrane-ready gypsum panel, wherein the material coating comprises a substantially smooth outer surface.
2 . The method of claim 1 , wherein the first fibrous mat has a mat coating on the surface of the first fibrous mat opposite the gypsum slurry.
3 . The method of claim 1 , wherein the second fibrous mat has a mat coating on the surface of the second fibrous mat opposite the gypsum slurry.
4 . The method of claim 1 , wherein applying the adhesive coating composition occurs after drying the gypsum sandwich structure.
5 . The method of claim 1 , wherein applying the adhesive coating composition occurs before drying the gypsum sandwich structure.
6 . The method of claim 1 , wherein the adhesive coating composition is applied such that the outer surface has a finish from about a level 1 finish to about a level 5 finish.
7 . The method of claim 1 , wherein the adhesive coating composition contains solids in an amount from about 35 to about 100 weight percent.
8 . The method of claim 1 , wherein the adhesive coating composition comprises a polymer or a copolymer with a glass transition temperature of 0 to 30° C.
9 . The method of claim 1 , wherein depositing a gypsum slurry comprises:
depositing a first gypsum slurry onto the surface of the first fibrous mat; and
depositing a second gypsum slurry onto the first gypsum slurry, the second gypsum slurry having a lower density than the first gypsum slurry.
10 . The method of claim 1 , further comprising:
attaching the membrane-ready gypsum panel to a building; and
applying a membrane to the substantially smooth outer surface of the membrane-ready gypsum panel.
11 . The method of claim 10 , wherein the membrane comprises WIP 300 HT, WIP 200, MiraDRI 860, MiraDRI 861, Blueskin SA, Blueskin LT, PermaBarrier Wall membrane, or PermaBarrier Wall flashing.
12 . The method of claim 1 , wherein the first fibrous mat is a fiberglass mat.
13 . The method of claim 1 , wherein the first fibrous mat is paper.
14 . An apparatus for fabricating membrane-ready gypsum panels, comprising:
a board line for transporting a first fibrous mat;
a depositing mechanism configured to deposit a gypsum slurry onto a surface of the first fibrous mat;
a conveyor configured to deposit a second fibrous mat onto a surface of the gypsum slurry opposite the first fibrous mat, such that a surface of the second fibrous mat contacts the gypsum slurry, to form a gypsum sandwich structure on the board line;
a dryer for drying the gypsum sandwich structure;
an applicator configured to apply an adhesive coating composition to a surface of the first fibrous mat opposite the gypsum slurry, such that the adhesive coating composition covers the surface of the first fibrous mat; and
a dryer for drying the adhesive coating composition to provide a material coating and form a membrane-ready gypsum panel, wherein the material coating comprises a substantially smooth outer surface.
15 . The apparatus of claim 14 , further comprising a transfer mechanism configured to overturn the gypsum sandwich structure such that the surface of the first coated fibrous mat opposite the gypsum slurry is exposed prior to application of the adhesive coating composition.
16 . A membrane-ready gypsum panel, comprising:
a first fibrous mat having a first surface and a second surface;
a second fibrous mat having a first surface and a second surface;
a gypsum core in contact with the second surfaces of the first and second fibrous mats; and
a material coating that covers at least a portion of the first surface of the first fibrous mat and forms a substantially smooth outer surface thereon.
17 . The membrane-ready gypsum panel of claim 16 , wherein the outer surface of the material coating has a finish from about a level 1 finish to about a level 5 finish.
18 . The membrane-ready gypsum panel of claim 16 , wherein the gypsum core comprises:
a first gypsum layer in contact with the second surface of the first fibrous mat; and
a second gypsum layer having a lower density than the first gypsum layer and in contact with the first gypsum layer and the second surface of the second fibrous mat.
19 . The membrane-ready gypsum panel of claim 16 , wherein the membrane-ready gypsum panel has a Cobb value below 5 grams.
20 . The membrane-ready gypsum panel of claim 16 , wherein the membrane-ready gypsum panel has a vapor permeance equal to or greater than 1.5 perms.
21 . The membrane-ready gypsum panel of claim 16 , wherein the material coating has a weight from about 5 lbs/MSF (24.41 g per 1000 sq m) to about 100 lbs/MSF (4882.43 g per 1000 sq m).
22 . The membrane-ready gypsum panel of claim 16 , wherein the outer surface is substantially smooth such that a self-adhering membrane applied directly to the outer surface of the membrane-ready gypsum panel has a peel strength of above 3 pounds per linear inch at 72° F. (535.7 g/cm at 22.2° C.).
23 . The membrane-ready gypsum panel of claim 16 , wherein the first and second fibrous mats each comprise a non-woven fibrous mat comprising glass fibers.
24 . The membrane-ready gypsum panel of claim 16 , wherein the first and second fibrous mats each comprise paper.
25 . The membrane-ready gypsum panel of claim 23 , wherein the glass fibers have an average diameter from about 10 to about 17 microns and an average length from about one-quarter (¼) inch to about three-quarter (¾) inch (0.64 to 1.91 cm).
26 . A method for coating an unattached, exterior gypsum wallboard to make the wallboard membrane-ready, comprising the steps of:
applying an adhesive coating composition to an exposed surface of a fibrous mat of an exterior gypsum panel, wherein the adhesive coating composition comprises water and an acrylic latex; and
drying the adhesive coating composition to form a material coating, wherein the coating provides a non-tacky, substantially smooth outer surface capable of adhering to an adhesive-backed membrane, and the coating composition penetrates the fibrous mat to enhance the cohesive strength thereof.
27 . The method of claim 26 , further comprising:
attaching the membrane-ready gypsum wallboard to a building; and
applying a membrane to the substantially smooth outer surface of the membrane-ready gypsum panel without a field-applied adhesive.
28 . The method of claim 27 , wherein the membrane has a peel strength of above 3 pounds per linear inch at 72° F. (535.7 g/cm at 22.2° C.).