U.S. patent application number 14/468860 was filed with the patent office on 2015-03-05 for membrane-ready fibrous faced gypsum panels, apparatus, and methods.
The applicant listed for this patent is Georgia-Pacific Gypsum LLC, Valspar Sourcing, Inc.. Invention is credited to James E. Bailey, Brian W. Bland, Ali Fadhel, Michael D. Foster, Shaobing Wu.
Application Number | 20150064433 14/468860 |
Document ID | / |
Family ID | 52583641 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150064433 |
Kind Code |
A1 |
Foster; Michael D. ; et
al. |
March 5, 2015 |
MEMBRANE-READY FIBROUS FACED GYPSUM PANELS, APPARATUS, AND
METHODS
Abstract
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.
Inventors: |
Foster; Michael D.;
(Jamestown, NC) ; Bland; Brian W.; (Matthews,
NC) ; Fadhel; Ali; (Atlanta, GA) ; Bailey;
James E.; (Trinity, NC) ; Wu; Shaobing;
(Jamestown, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Georgia-Pacific Gypsum LLC
Valspar Sourcing, Inc. |
Atlanta
Minneapolis |
GA
MN |
US
US |
|
|
Family ID: |
52583641 |
Appl. No.: |
14/468860 |
Filed: |
August 26, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61870341 |
Aug 27, 2013 |
|
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|
61870602 |
Aug 27, 2013 |
|
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Current U.S.
Class: |
428/218 ;
156/346; 156/45; 427/372.2; 428/341; 428/354; 428/537.7; 428/703;
442/386 |
Current CPC
Class: |
Y10T 428/2848 20150115;
C09J 133/08 20130101; B32B 29/005 20130101; B32B 2607/00 20130101;
B32B 2307/546 20130101; B32B 9/045 20130101; B32B 37/24 20130101;
B32B 2315/18 20130101; B32B 38/164 20130101; B32B 2398/10 20130101;
B28B 23/0006 20130101; B32B 37/15 20130101; C04B 2111/00629
20130101; B32B 29/002 20130101; C04B 28/14 20130101; E04C 2/26
20130101; B32B 27/308 20130101; B32B 2307/54 20130101; B32B
2317/125 20130101; Y10T 442/665 20150401; Y10T 428/273 20150115;
Y10T 428/31906 20150401; Y10T 428/31996 20150401; C04B 14/42
20130101; C04B 24/2623 20130101; C04B 38/10 20130101; B28B 19/0092
20130101; B32B 2250/20 20130101; E04C 2/043 20130101; B32B 2255/12
20130101; B32B 2262/101 20130101; C04B 28/14 20130101; Y10T
428/24992 20150115; B32B 2037/243 20130101; B32B 37/12 20130101;
B32B 2607/02 20130101; B32B 27/10 20130101; B32B 2250/04 20130101;
B32B 5/26 20130101; B32B 13/14 20130101; B28B 11/04 20130101; B32B
2255/02 20130101; B32B 2305/20 20130101 |
Class at
Publication: |
428/218 ;
428/703; 428/341; 428/354; 428/537.7; 442/386; 156/45; 156/346;
427/372.2 |
International
Class: |
E04C 2/26 20060101
E04C002/26; E04C 2/04 20060101 E04C002/04; E04C 2/24 20060101
E04C002/24 |
Claims
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.degree. 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.degree. F. (535.7 g/cm at 22.2.degree. 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 (1/4) inch to about
three-quarter (3/4) 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.degree. F. (535.7
g/cm at 22.2.degree. C.).
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/870,341, filed on Aug. 27, 2013, which is
incorporated by reference herein in its entirety.
[0002] Reference is further made to U.S. Provisional Application
No. 61/870,602, filed on Aug. 27, 2013, entitled COATING AND BINDER
COMPOSITIONS FOR GYPSUM BOARDS, which is incorporated by reference
herein in its entirety.
BACKGROUND
[0003] The present disclosure relates generally to the field of
panels for use in building construction, and more particularly to
membrane-ready fibrous faced gypsum panels for use with air barrier
membranes.
[0004] Many modern building codes require the use of vapor barriers
in construction to protect the building from air and water
penetration. For example, building codes in eastern Canada and the
northeastern United States now require air barriers to be used in
all construction. Moreover, the 2006 International Building
Code/International Residential Code (IBC/IRC) requires the use of a
weather restrictive air barrier for all new construction. Air
barriers may be formed from a variety of materials and structures
and applied to the surface of construction sheathing materials
(e.g., fibrous faced gypsum panels).
[0005] A popular air barrier system is self-adhered (i.e., "peel
and stick") membranes. Current peel and stick membranes require the
surface of the sheathing material to be coated with adhesive in the
field before the membrane may be applied, which significantly slows
down the construction process. Additionally, the adhesive
application step is estimated to cost the contractor $0.20/ft.sup.2
($2.15/m.sup.2) in labor and materials.
[0006] Accordingly, it would be desirable to provide a sheathing
panel that can be used with peel and stick membranes and requires
minimal or no field applied adhesive.
SUMMARY
[0007] In one aspect, the present disclosure is directed to a
method of making an unattached, membrane-ready, exterior gypsum
panel, including: [0008] depositing a gypsum slurry onto a surface
of a first fibrous mat; [0009] 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; [0010] drying the
gypsum sandwich structure; [0011] 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 [0012] 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 includes a substantially smooth outer
surface.
[0013] In another aspect, the present disclosure is directed to an
apparatus for fabricating membrane-ready gypsum panels, including:
[0014] a board line for transporting a first fibrous mat; [0015] a
depositing mechanism configured to deposit a gypsum slurry onto a
surface of the first fibrous mat; [0016] 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; [0017] a dryer for drying the gypsum
sandwich structure; [0018] 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 [0019]
a dryer for drying the adhesive coating composition to provide a
material coating and form a membrane-ready gypsum panel, wherein
the material coating includes a substantially smooth outer
surface.
[0020] In yet another aspect, the present disclosure is directed to
a membrane-ready gypsum panel, including: [0021] a first fibrous
mat having a first surface and a second surface; [0022] a second
fibrous mat having a first surface and a second surface; [0023] a
gypsum core in contact with the second surfaces of the first and
second fibrous mats; and [0024] 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, wherein the
material coating is derived from an adhesive coating composition
including a polymeric adhesive. In one embodiment, the polymeric
adhesive includes an aqueous emulsion selected from acrylics,
styrene acrylics, vinyl acrylics, styrene acetate acrylics, and
combinations thereof.
[0025] In yet another embodiment, the present disclosure is
directed to a method for coating an unattached, exterior gypsum
wallboard to make the wallboard membrane-ready, including the steps
of: [0026] applying an adhesive coating composition to an exposed
surface of a fibrous mat of an exterior gypsum panel, wherein the
adhesive coating composition includes water and an acrylic latex;
and [0027] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Referring now to the drawings, which are meant to be
exemplary and not limiting, and wherein like elements are numbered
alike:
[0029] FIG. 1 is a cross-sectional view of an embodiment of a
membrane-ready gypsum panel.
[0030] FIG. 2 is a schematic of an embodiment of an in-process
coating application apparatus.
[0031] FIG. 3 is a schematic of an embodiment of a post-process
coating application apparatus.
DETAILED DESCRIPTION
[0032] Disclosed herein are membrane-ready gypsum panels and
methods and apparatus for manufacturing membrane-ready gypsum
panels. The membrane-ready panels have a substantially smooth outer
surface that can be used with peel and stick membranes using
minimal or no field-applied adhesive.
[0033] As used herein, the term "membrane-ready" refers to panels
that are configured with a material coating layer during the panel
manufacturing process and have a substantially smooth outer surface
that can be used with peel and stick membranes using minimal or no
field-applied adhesive.
[0034] As used herein, the terms "peel and stick," "self-adhering,"
or "self-sealing," membranes refer to adhesive-backed air and
moisture impermeable membranes, or moisture permeable membranes,
commonly used in the building construction industry. For example,
in some embodiments the self-adhering membranes may be asphalt
backed membranes. Exemplary self-adhering membranes include
PERM-A-BARRIER wall membranes or wall flashings, commercially
available from Grace Construction (Cambridge, Mass.); BLUESKIN SA
or LT, commercially available from Henry Company (El Segundo,
Calif.); MIRADRI 860 or 861, commercially available from Carlisle
Coatings and Waterproofing (Wylie, Tex.); and WIP 300 HT or 200,
commercially available from Carlisle Residential (Carlisle, Pa.).
In other embodiments, the membranes may include nonwoven moisture
permeable membranes such as those available from E.I DuPont,
Wilmington, Del., under the trade designation TYVEK.
Panels
[0035] As shown in FIG. 1, in one embodiment, a membrane-ready
gypsum panel 100 includes a first fibrous mat 104 having a first
surface 104A and a second surface 104B, and a second fibrous mat
114 having a first surface 114A and a second surface 114B. A gypsum
core 101 is in contact with the second surfaces 104B, 114B of the
first and second fibrous mats 104, 114. A material coating 102
covers the first surface 104A of the first fibrous mat 104 and
forms a substantially smooth outer surface 116. As used herein, the
term "substantially smooth" refers to the outer surface being
completely or mostly free of texturing and voids. For example, the
substantially smooth outer surface may have a board finish from
about a level 1 finish to about a level 5 finish, according to ASTM
C11, ASTM C840, and GA-216 standards for gypsum boards. In one
embodiment, the outer surface has a level 5 finish.
[0036] In certain embodiments, the panels 100 have a thickness from
about 1/4inch (0.64 cm) to about 1 inch (2.54 cm). For example, the
panels 100 may have a thickness of about 1/2 inch (1.27 cm), about
3/4inch (1.91 cm), or about 7/8 inch (2.22 cm).
[0037] The gypsum core 101 may be similar to those used in other
gypsum products, such as, for example, gypsum wallboard, dry wall,
gypsum board, gypsum lath, and gypsum sheathing. For example, the
gypsum core 101 may be formed by mixing water with powdered
anhydrous calcium sulfate or calcium sulfate hemi-hydrate, also
known as calcined gypsum, to form an aqueous gypsum slurry, and
thereafter allowing the slurry mixture to hydrate or set into
calcium sulfate dihydrate, a relatively hard material. The gypsum
core may include about 80 weight percent or above of set gypsum
(i.e., fully hydrated calcium sulfate). For example, the gypsum
core may include about 85 weight percent set gypsum. The gypsum
core may also include a variety of additives, such as accelerators,
set retarders, foaming agents, and dispersing agents.
[0038] In certain embodiments, the gypsum core 101 also includes
reinforcing fibers, such as chopped glass fibers. For example, the
gypsum core 101 may include up to about 0.6 pounds of reinforcing
fibers per 100 square feet (29.3 g/m.sup.2) of panel. For example,
the gypsum core 101 may include about 0.3 pounds of reinforcing
fibers per 100 square feet (14.6 g/m.sup.2) of panel. The
reinforcing fibers may have a diameter between about 10 and about
17 microns and have a length between about 1/4 to 1/2 inch (0.64 to
0.12 cm).
[0039] The gypsum core 101 may also include an additive that
improves the water-resistant properties of the core. Such additives
may include, for example, poly(vinyl alcohol), optionally including
a minor amount of poly(vinyl acetate); metallic resinates; wax,
asphalt, or mixtures thereof, for example as an emulsion; a mixture
of wax and/or asphalt and cornflower and potassium permanganate;
water insoluble thermoplastic organic materials such as petroleum
and natural asphalt, coal tar, and thermoplastic synthetic resins
such as poly(vinyl acetate), poly(vinyl chloride), and a copolymer
of vinyl acetate and vinyl chloride, and acrylic resins; a mixture
of metal rosin soap, a water soluble alkaline earth metal salt, and
residual fuel oil; a mixture of petroleum wax in the form of an
emulsion and either residual fuel oil, pine tar, or coal tar; a
mixture of residual fuel oil and rosin; aromatic isocyanates and
diisocyanates; organopolysiloxanes; siliconates; a wax emulsion and
a wax-asphalt emulsion, each optionally with potassium sulfate,
alkali, or alkaline earth aluminates, and Portland cement; a
wax-asphalt emulsion prepared by adding to a blend of molten wax
and asphalt, an oil-soluble, water-dispersing emulsifying agent,
and admixing the aforementioned with a solution of case including,
as a dispersing agent, an alkali sulfonate of a polyarylmethylene
condensation product. Mixtures of these water-resistance additives
may also be employed. For example, a mixture of two or more of:
poly(vinyl alcohol), siliconates, wax emulsion, and wax-asphalt
emulsion of the aforementioned types, may be used to improve the
water resistance of the gypsum core 101.
[0040] In certain embodiments, the gypsum core 101 has a density
from about 130 pounds per 100 square feet to about 145 pounds per
100 square feet (6347.1-7079.5 g/m.sup.2). For example, the gypsum
core 101 may have a density of about 135 pounds per 100 square feet
(6591.3 g/m.sup.2). In certain embodiments, the gypsum core 101
includes a first gypsum layer 108 in contact with the second
surface 104B of the first fibrous mat 104 and a second gypsum layer
110 having a lower density than the first gypsum layer 108 and in
contact with the first gypsum layer 108 and the second surface 114B
of the second fibrous mat 114. For example, the first gypsum layer
108 may be a densified gypsum layer having a density about 15 to
about 25 percent greater than the density of the second gypsum
layer 110.
[0041] As shown in FIG. 1, in certain embodiments, both surfaces of
the 101 gypsum core are faced with coated fibrous mats 104, 114.
The mats 104, 114 include a plurality of fibers 115 that are
typically enmeshed or entangled with the gypsum core 101 at the
surface interfaces 106, 112.
[0042] In certain embodiments, the fibrous mats 104, 114 include a
non-woven mat of fiber material that is capable of forming a strong
bond with the set gypsum of the gypsum core 101 through a
mechanical-like interlocking between the interstices between the
fibers 115 of the fibrous mats 104, 114 and portions of the gypsum
core 101. Examples of fiber materials for use as the fibers 115 in
the non-woven mats 104, 114 include mineral-type materials such as
glass fibers, cellulosic fibers (e.g., paper), synthetic resin
fibers, and mixtures or blends thereof. Both chopped strands and
continuous strands may be used.
[0043] In certain embodiments, the mats 104, 114 are non-woven
fiberglass mats. For example, the glass fibers 115 in the mats 104,
114 may an average diameter from about 10 to about 17 microns and
an average length from about 1/4inch to about 3/4inch (0.64 to 1.91
cm). For example, the glass fibers 115 may have an average diameter
of 13 microns (i.e., K fibers) and an average length of 3/4inch. In
certain embodiments, the non-woven fiberglass mats 104, 114 have a
basis weight from about 1.5 pounds to about 2.5 pounds per 100
square feet (73.2-122.1 g/m.sup.2) of the mat. The mats 104, 114
may each have a thickness from about 20 mils to about 26 mils.
[0044] The strands of the fibers 115 may be bonded together to form
a unitary mat structure by a suitable adhesive. For example, the
adhesive may be an amine-aldehyde resin (e.g., urea-formaldehyde
resin) adhesive, optionally modified with a thermoplastic extender
or cross-linker, such as an acrylic cross-linker, or an acrylate
adhesive resin.
[0045] The fibrous mats 104, 114 may each also include a mat
coating 120, 122 on one or both surfaces of the non-woven fibrous
mat. For example, as shown in FIG. 1, the first and second fibrous
mats 104, 114 may each be coated on the surface of the mat opposite
the gypsum slurry 101. The mat coating 120, 122 may include a
filler and an adhesive binder. In certain embodiments, the binder
makes up from about 1% to about 17% of the mat coating 120, 122, on
a dry weight basis, with the balance being the filler. Thus, the
weight ratio of the filler to the binder may be from about 5:1 to
about 20:1. In one embodiment, the mat coating 120, 122 has a basis
weight from about 3 to about 6 pounds of solids per 100 square feet
(146.5-292.9 g/m.sup.2) of the non-woven fibrous mat 104, 114.
[0046] In certain embodiments, the filler of the mat coating 120,
122 is an inorganic, mineral filler. For example, the filler may be
ground limestone (calcium carbonate), clay, sand, mica, talc,
gypsum (calcium sulfate dihydrate), aluminum trihydrate (ATH),
antimony oxide, or any combination thereof. The filler may be in a
particulate form. For example, the filler may have a particle size
such that at least 95% of the particles pass through a 100 mesh
wire screen.
[0047] In certain embodiments, the filler may inherently contain a
naturally occurring inorganic adhesive binder. For example, the
filler may be limestone containing quicklime (CaO), clay containing
calcium silicate, sand containing calcium silicate, aluminum
trihydrate containing aluminum hydroxide, cementitious fly ash, or
magnesium oxide containing either the sulfate or chloride of
magnesium, or both. In certain embodiments, the filler may include
an inorganic adhesive binder as a constituent, cure by hydration,
and act as a flame suppressant. For example, the filler may be
aluminum trihydrate (ATH), calcium sulfate (gypsum), and the
oxychloride and oxysulfate of magnesium.
[0048] In certain embodiments, the binder of the mat coating 120,
122 is a polymer latex adhesive. For example, the binder may be
styrene-butadiene-rubber (SBR), styrene-butadiene-styrene (SBS),
ethylene-vinyl-chloride (EVCl), poly-vinylidene-chloride (PVdCl)
and poly(vinylidene) copolymers, modified poly-vinyl-chloride
(PVC), poly-vinyl-alcohol (PVOH), ethylene-vinyl-acetate (EVA),
poly-vinyl-acetate (PVA) and polymers and copolymers containing
units of acrylic acid, methacrylic acid, their esters and
derivatives thereof (acrylic-type polymers), such as
styrene-acrylate copolymers.
[0049] In one embodiment, the binder is a hydrophobic, UV resistant
polymer latex adhesive. For example, the hydrophobic, UV resistant
polymer latex binder adhesive may be based on a (meth)acrylate
polymer latex, wherein the (meth)acrylate polymer is a lower alkyl
ester, such as a methyl, ethyl or butyl ester, of acrylic and/or
methacrylic acids, and copolymers of such esters with minor amounts
of other ethylenically unsaturated copolymerizable monomers (such
as stryrene) which are known to the art to be suitable in the
preparation of UV resistant (meth)acrylic polymer latexes.
[0050] In certain embodiments, the mat coating composition that
forms the mat coatings 120, 122 also includes water and/or other
optional ingredients such as colorants (e.g., dyes or pigments),
thickeners or rheological control agents, defoamers, dispersants,
and preservatives.
[0051] A material coating 102 covers the first surface 104A of the
first fibrous mat 104 and forms a substantially smooth outer
surface 116. The material coating 102 is derived from an adhesive
composition that can include a wide variety of polymeric adhesives.
A variety of polymers may be employed in the adhesive composition,
including latex polymers, water-dispersible polymers,
water-reducible polymers, and oil-modified polymers.
[0052] Suitable latex polymers include (meth)acrylics, vinyls,
polyesters, polyurethanes, polyamides, chlorinated polyolefins,
ethylene vinyl acetate, polybutadiene, polyvinylidene, styrene
acrylics, vinyl acrylics, vinyl versatic acid esters,
styrene/butadiene, epoxy esters, polyureas, polysiloxanes,
silicones, fluorinated copolymers, and mixtures or copolymers
thereof. Such latex polymers normally contain at least polymeric
particles, water, and one or more emulsifiers. The waterborne latex
polymer particles may include one or more functional groups capable
of reacting with an external crosslinker, and such external
crosslinker may also be a part of the disclosed compositions.
[0053] Suitable latex polymers are typically stabilized using one
or more nonionic or anionic emulsifiers (viz., surfactants), used
either alone or together. If desired, the latex polymers may be
stabilized with an alkali-soluble polymer. A water-soluble free
radical initiator is typically used in the polymerization of a
latex polymer. The latex polymer may optionally also be
functionalized with olefinic groups or other crosslinkable groups
where it is desired to enable the latex polymer to participate in
radiation curing.
[0054] Exemplary commercially available latex polymers include
ALBERDINGK AC 2514, ALBERDINGK AC 25142, ALBERDINGK AC 2518,
ALBERDINGK AC 2523, ALBERDINGK AC 2524, ALBERDINGK AC 2537,
ALBERDINGK AC 25381, ALBERDINGK AC 2544, ALBERDINGK AC 2546,
ALBERDINGK MAC 24, and ALBERDINGK MAC 34 polymer dispersions from
Alberdingk Boley, Inc.; AQUAMAC 720 from Hexion Specialty
Chemicals; EPS 2538 acrylic latex, EPS 2540 styrene acrylic latex
and EPS 2725 acrylic latex emulsions from Engineered Polymer
Solutions, Inc. ("EPS"); RESYN.TM. 7305 vinyl acrylic emulsion from
Celanese Emulsion Polymers; RHOPLEX.TM. 3131-LO, RHOPLEX E-693,
RHOPLEX E-940, RHOPLEX E-1011, RHOPLEX E-2780, RHOPLEX HG-95P,
RHOPLEX HG-700, RHOPLEX HG-706, RHOPLEX PR-33, RHOPLEX TR-934HS,
RHOPLEX TR-3349 and RHOPLEX VSR-1050 acrylic emulsions from Rohm
and Haas Co.; RHO SHIELD.TM. 636 and RHOSHIELD 3188 polymer
dispersions from Rohm and Haas Co.; JONCRYL.TM. 538, JONCRYL 1552,
JONCRYL 1972, JONCRYL 1980, JONCRYL 1982, JONCRYL 1984 and JONCRYL
8383 acrylic emulsions from BASF Resins; NEOCRYL.TM. A-1127,
NEOCRYL A-6115, NEOCRYL XK-12, NEOCRYL XK-90, NEOCRYL XK-98 and
NEOCRYL XK-220 acrylic latex polymers from DSM NeoResins, Inc., and
mixtures thereof.
[0055] The adhesive composition may alternatively or optionally
contain a water-dispersible or water-reducible polymer. Exemplary
water-dispersible polymers include polyurethanes, polyamides,
chlorinated polyolefins, (meth)acrylics, vinyls, polyesters, and
mixtures or copolymers thereof. The water-dispersible polymer
typically will include as a part of the polymer a group or groups
which render the polymer dispersible by itself in water. The
water-dispersible polymer may optionally also be functionalized
with olefinic groups or other crosslinkable groups where it is
desired to enable the water-dispersible polymer to participate in
radiation curing.
[0056] Exemplary commercially available water-dispersible or
water-reducible polymers include acrylic copolymers available from
BASF Corporation under the trade designation JONCRYL; PARALOID.TM.
WR-97 water-reducible acrylic resin from Dow Coating Materials;
AROLON.TM. 562-G2-70 water-reducible acrylic resin from Reichhold
Inc.; MAINCOTE.TM. HG-54D and RHOPLEX.TM. WL-96 waterborne acrylic
resins from Rohm and Haas Co.; AQUAMAC.TM. thermoplastic styrene
acrylic latex resin from Momentive Specialty Chemicals Inc.;
CARBOSET.TM. CR-760 and CARBOSET CR-765 thermoplastic
styrene-acrylic copolymer emulsions from Lubrizol Advanced
Materials, Inc.; TEXICRYL.TM. acrylic and styrene acrylate
dispersions from Scott Bader Inc.; TEXIGEL.TM. dispersions from
Scott Bader Inc.; EPS 6208 water-reducible alkyd resin from EPS;
ANCAREZ.TM. AR555 water-reducible epoxy resin from Air Products and
Chemicals, Inc.; BECKOPDX.TM. EP386W/56WA water-reducible epoxy
resin from Cytec Industries; EPS 3216 water-reducible polyester
resin from EPS; EPS 4213 polyurethane dispersion from EPS;
BAYHYDROL.TM. PR 240 polyurethane dispersion from Bayer Material
Science; and POLIDENE.TM. vinylidene chloride copolymer emulsions
from Scott Bader Inc.
[0057] Oil-modified polymers may also be used as latex polymers or
if appropriately stabilized as water-dispersible polymers. As used
herein, oil-modified polymers include polymers that contain oils or
oil based derivatives such as glyceride oils (monoglycerides,
diglycerides, and the like), fatty acids, fatty amines, and
mixtures thereof. Examples of such oil-modified polymers include
alkyds, oil-modified polyurethanes, oil-modified polyamides,
oil-modified acrylics, and mixtures or copolymers thereof.
[0058] In various embodiments, the adhesive compositions that give
rise to the material coating 102 contain about 90 to about 30% by
weight latex or water-dispersible polymer based on the total weight
of the non-volatile components in the coating system, about 80 to
about 35% by weight, or about 70 to about 40% by weight. If a
water-dispersible polymer is also employed, it may be present in an
amount less than the amount of latex polymer.
[0059] In some embodiments, aqueous emulsions such as acrylics,
styrene acrylics, and vinyl acrylics have been found to work well
in the adhesive composition. In some embodiments, the polymers and
copolymers in these emulsions have a glass transition temperature
(Tg) of about -45.degree. C. to about 115.degree. C., and in other
embodiments the polymers and copolymers can have glass transition
temperatures (Tg) of about 0.degree. C. to about 30.degree. C. In
some embodiments, (meth)acryl monomers can be copolymerized with
styrene or vinyl monomers, and may be incorporated into the gypsum
slurry in water-borne or 100% solids form. In some embodiments, the
resins range in pH from about 1.5 to about 11, or from about 1.78
to about 10.0, have particle sizes that range from about 30 to
about 400 nanometers, and NVM ranges from about 21% to about
65%.
[0060] Suitable polymers for use in the adhesive composition
include, but are not limited to, acrylic aqueous emulsions
available from EPS, under the trade designations EPS 2103, EPS
2111, EPS 2113, EPS 2117, EPS 2257, EPS 2293, EPS 2705, EPS 2708,
EPS 2757 and EPS 2772, as well as styrene acrylic aqueous emulsions
EPS 2272, EPS 2507, EPS 2510, EPS 2512, EPS 2514, EPS 2526, EPS
2533, EPS 2535, EPS 2537, EPS 2548, EPS 2550, EPS 2561, EPS 2568,
EPS 2572, and EPS 2851. Other examples include vinyl acetate
acrylic copolymer emulsions available from Dow Chemical Co.,
Midland, Mich., under the trade designation Rovace, particularly
Rovace 9100.
[0061] In various embodiments, the adhesive composition may also
include a wide range of additives including, but not limited to,
water, glass, paper or wood fibers, mineral fillers, strength
additives, accelerators, retarders, crystallized gypsum particles,
surfactants, dispersants, fire retarders, water absorbers, water
repellants, mold inhibitors, ultraviolet (UV) light resistant
compounds, pH adjusters, rheology modifiers, flow control agents,
defoamers, and the like.
[0062] Suitable thickeners may include hydroxyethyl cellulose;
hydrophobically modified ethylene oxide urethane; processed
attapulgite, a hydrated magnesium aluminosilicate; and other
thickeners known to those of ordinary skill in the art. For
example, thickeners may include CELLOSIZE QP-09-L and ACRYSOL
RM-2020NPR, commercially available from Dow Chemical Company
(Philadelphia, Pa.); and ATTAGEL 50, commercially available from
BASF Corporation (Florham Park, N.J.). In other embodiments,
nonionic surfactants may be incorporated into the adhesive
composition. Examples include, but are not limited to, compounds of
block copolymers based on ethylene oxide and propylene oxide
available under the trade designation Pluronic from BASF SE, such
as Pluronic L31 (difunctional block copolymer terminating in
primary hydroxyl groups), Pluronic 17R2 (difunctional block
copolymer terminating in secondary hydroxyl groups), and Pluronic
25R2 (difunctional block copolymer terminating in secondary
hydroxyl groups). These compounds have an HLB value of about 1 to
about 7. Other suitable surfactants include nonionic octylphenol
ethoxylates and nonionic nonylphenol ethoxylate available from Dow
Chemical Co. under the trade designation Triton X-405 (HLB=17-18)
and Tergitol NP-10 (HLB=13-14), as well as other nonionic
surfactants like those available from Air Products and Chemicals,
Allentown Pa., under the trade designation Dynol, particularly
Dynol 607 (HLB=8). Other suitable surfactants may include
HYDROPALAT 44, commercially available from BASF Corporation.
[0063] Defoamers may include multi-hydrophobe blend defoamers and
other defoamers known to those of ordinary skill in the art. For
example, defoamers may include FOAMASTER SA-3, commercially
available from BASF Corporation.
[0064] Fillers may include inorganic, mineral fillers, such as
sodium-potassium alumina silicates, microcrystalline silica, talc
(magnesium silicate), and the like. For example, fillers may
include MINEX 7, commercially available from the Cary Company
(Addison, Ill.); IMSIL A-10, commercially available from the Cary
Company; and TALCRON MP 44-26, commercially available from
Specialty Minerals Inc. (Dillon, Mont.).
[0065] Biocides may include broad-spectrum microbiocides that
prohibit bacteria and fungi growth, antimicrobials such as those
based on the active diiodomethyl-ptolylsulfone, and other compounds
known to those of ordinary skill in the art. For example, biocides
may include KATHON LX 1.5%, commercially available from Dow
Chemical Company, POLYPHASE 663, commercially available from Troy
Corporation (Newark, N.J.), and AMICAL Flowable, commercially
available from Dow Chemical Company. Biocides may also act as
preservatives.
[0066] Ultraviolet (UV) absorbers may include encapsulated
hydroxyphenyl-triazine compositions and other compounds known to
those of ordinary skill in the art, for example, TINUVIN 477DW,
commercially available from BASF Corporation.
[0067] Transfer agents such as polyvinyl alcohol (PVA) and other
compounds may also be included in the material coating
composition.
[0068] In some embodiments, the adhesive composition may optionally
include an ammonia composition including ammonium hydroxide, for
example, AQUA AMMONIA 26 BE, commercially available from Tanner
Industries, Inc. (Southampton, Pa.).
[0069] These additives are optionally present in the adhesive
composition at up to about 5 wt %, or at about 0.01 wt % to about 2
wt %, or about 0.1 wt % to about 1 wt %, based on the total weight
of the composition.
[0070] The adhesive composition from which the material coating 102
is derived may be varied based on the type of applicator used to
apply the adhesive composition to the first fibrous mat 104. For
example, for curtain coat applicators, the adhesive composition may
be formulated as given in Table 1. In some embodiments, the curtain
coat compositions may include a self-crosslinking latex that allows
the gypsum panel 100 to be completely covered by the primer and not
block when stacking
TABLE-US-00001 TABLE 1 Material Coating Composition for Curtain
coat Applicators Composition 1 Composition 2 Ingredients
Description (Parts By Wt) (Parts By Wt) Water 10.59 16.28 Thickener
1.34 1.10 Surfactant 0.71 1.22 Defoamer 0.11 0.20 Base 0.05 0.10
Minex 7 Filler 7.52 12.70 Imsil A-10 Filler 6.98 11.80 Talcron MP
44-26 Filler 7.52 12.70 Biocide 0.47 0.40 Joncryl 1987 Self
Crosslinking 63.91 43.00 Latex UV Absorber 0.8 0.20
[0071] In another embodiment, for direct roll coat applicators, the
adhesive composition may be formulated as given in Table 2. The
direct roll coating composition may include a PVOH transfer agent
that allows for higher application rates with the increased
smoothness needed for improved interfacial adhesion.
TABLE-US-00002 TABLE 2 Material Coating Composition for Direct Roll
Coat Applicator Composition Ingredients Description (Parts By Wt)
Water Water 29.36 Thickener 1.19 Surfactant 1.43 Defoamer 0.2 Base
0.15 Minex 4 Filler 18.88 Imsil A-10 Filler 12.92 Talcron MP 44-26
Filler 11.92 Biocide 0.55 Acrylic emulsion Latex 22.66 PVA Solution
Transfer Agent 0.74
[0072] In another embodiment, for airless applicators, the adhesive
composition may be formulated as given in Table 3. The airless
coating composition may have a reduced viscosity to allow a more
uniform deposition due to finer atomization of the coating.
TABLE-US-00003 TABLE 3 Material Coating Compostion for Airless
Applicators Composition Ingredients Description (Parts By Wt) Water
29.23 Thickener 0.90 Surfactant 1.40 Defoamer 0.20 Base 0.15 Minex
4 Filler 19.00 Imsil A-10 Filler 13.00 Talcron MP 44-26 Filler
12.00 Biocide 0.55 Acrylic emulsion Latex 22.84 PVA Solution
Transfer Agent 0.73
[0073] In certain embodiments, the adhesive composition giving rise
to the material coating 102 has an applied weight from about 5
pounds per 1000 sq ft (24.41 g per 1000 sq m) to about 100 pounds
per 1000 sq ft (4882.43 g per 1000 sq m). For example, the material
coating 102 may have an applied weight from about 6 pounds per 1000
sq ft (29.29 g per 1000 sq m) to about 10 pounds per 1000 sq ft
(48.82 g per 1000 sq m). In certain embodiments, the adhesive
composition from which the material coating 102 is derived contains
solids in an amount from about 35 to about 100 weight percent, or
from about 50 to about 60 weight percent.
[0074] The adhesive composition giving rise to the material coating
102 may be applied in an amount and composition such that a
self-adhering membrane (not shown in FIG. 1) applied directly to
the outer surface 116 of the membrane-ready gypsum panel 100 has a
peel strength similar to a traditional self-adhering membrane
applied with an adhesive primer, for example a peel strength above
3 pounds per linear inch (535.7 g/cm) at 22.2.degree. C. In one
embodiment, the adhesive composition giving rise to the material
coating 102 is applied on the surface 104A of the fibrous mat 104
such that a self-adhering membrane applied directly to the outer
surface 116 of the membrane-ready gypsum panel 101 has a peel
strength above from about 3.3 pounds per linear inch (589.3 g/cm)
to above about 5.1 pounds per linear inch (910.8 g/cm). In some
embodiments the fibers 115 from the fibrous mat 104 extend through
the mat coating 120 (if present) and into the material coating 102,
and the adhesive composition enters the interstices between the
fibers 115 such that the material coating 102 bonds to the fibrous
mat 104.
[0075] The membrane-ready gypsum panels 100 may be configured to
have certain material properties to keep water or air or both from
permeating the panels. For example, the membrane-ready gypsum panel
100 may have a Cobb value below about 5 grams, more preferably
below 2 grams, even more preferably below 0.84 grams. In one
embodiment, the membrane-ready gypsum panel 100 has a Cobb value of
0.5 grams or below. The membrane-ready gypsum panel 100 may also
have a vapor permeance equal to or greater than 1.5, more
preferably equal to or greater than 5, most preferably equal to or
greater than 10 perms. The membrane-ready gypsum panels 100 may
also have additional properties desirable for building materials.
For example, the membrane-ready gypsum panel 100 may have a class 1
fire rating according to the ASTM E84 standard. The membrane-ready
gypsum panel 100 may also have a mold growth resistance rating of
10 according to the ASTM D3273 standard.
Methods & Apparatus
[0076] Methods and apparatus for making membrane-ready gypsum
panels 100 as described herein are also provided. The method of
making a membrane-ready gypsum panel may include 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, and applying a material
coating to a surface of the first fibrous mat, such that the
material coating covers the surface of the first fibrous mat
opposite the gypsum slurry to form a membrane-ready gypsum panel
having a substantially smooth outer surface.
[0077] The first and second fibrous mats may be coated or uncoated
upon contacting the gypsum slurry. In certain embodiments, both the
first and second fibrous mats are coated on the surfaces opposite
the gypsum slurry. For example, coated fibrous mats may be obtained
in a pre-fabricated form. For example, the fibrous may be
wet-formed into a continuous non-woven web of any workable width,
coated with a binder, and dried to remove excess water and cure the
binder to form a fibrous mat. Any suitable method may be used to
apply a mat coating (i.e., the filler and binder composition
described above) to the fibrous mat, such as roller coating,
curtain coating, knife coating, spray coating and the like,
including combinations thereof. For example, the mat coating may be
applied in an amount from about 4 to pounds to about 12 pounds of
aqueous coating per 100 square feet (195.3-585.9 g/m.sup.2) of mat.
Following application of the aqueous coating to the mat, the
composition may be dried to cure the mat coating, usually by heat
to form the pre-coated mat. For example, the coated fibrous mats
may be prepared in accordance U.S. Patent Application Publication
No. 2009/0208714, which discloses using pre-coated non-woven
fibrous mats for improved adherence of gypsum board to membranes in
roofing applications. Thus, coated fibrous mats may be provided
having a dried, adherent coating applied to one of their surfaces.
These mats may be substantially liquid impermeable, but allow water
vapor to pass through during manufacturing of the gypsum panel.
[0078] In certain embodiments, a gypsum slurry may be deposited
onto a non-coated surface of a fibrous mat, i.e., the slurry is
deposited on a surface of the fibrous mat opposite the surface to
which the mat coating composition was applied. In certain
embodiments, the gypsum slurry contains excess water (i.e., water
in excess of that needed to hydrate the calcined gypsum from which
the slurry is made). Reinforcing fibers may also be included in the
gypsum slurry.
[0079] The slurry may be deposited on the non-coated side of a
horizontally oriented moving web of pre-coated fibrous mat. A
second coated fibrous mat may be deposited onto the surface of the
gypsum slurry opposite the first coated fibrous mat, i.e., the
non-coated surface of the second coated fibrous mat contacts the
gypsum slurry. For example, another moving web of a pre-coated
non-woven fibrous mat may be placed on the upper free surface of
the aqueous gypsum slurry. The gypsum slurry is sandwiched between
the coated fibrous mats. Using the coated fibrous mats may allow
the use of less coating and allow the fibrous mat to be saturated
with a gypsum slurry without excessive bleed through. This
saturating helps to insure a maximum bond of the fibrous mat to the
gypsum core.
[0080] In other embodiments, the fibrous mats are both uncoated,
only one mat is coated, the mats are coated on both surfaces, or
the mats are coated on the surfaces contacting the gypsum
slurry.
[0081] In certain embodiments, the step of depositing the gypsum
slurry includes 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.
[0082] The gypsum sandwich structure is subsequently dried to
evaporate the excess water from the gypsum slurry and set the
gypsum core. An adhesive coating composition as described above is
applied to an exposed surface of the first fibrous mat, i.e., the
outward-facing surface of the fibrous mat onto which the gypsum
slurry was deposited, and then may be at least partially cured or
dried to form a material coating layer. The adhesive coating
composition is applied to cover the surface of the first fibrous
mat opposite the gypsum and, when cured or dried, forms a
membrane-ready gypsum panel having a substantially smooth outer
surface suitable to accept a membrane. For example, the adhesive
coating composition may be applied to a coated surface of the first
fibrous mat opposite the gypsum. In certain embodiments, the step
of applying the adhesive coating composition occurs after drying
the gypsum sandwich structure. In alternative embodiments, the step
of applying the adhesive coating composition occurs before drying
the gypsum sandwich structure.
[0083] In certain embodiments, the adhesive coating composition is
applied by spray coating, ribbon coating, or direct roll coating
the material coating on the surface of the first fibrous mat
opposite the gypsum. For example, the adhesive coating composition
may be applied such that the exposed outer surface of the
membrane-ready gypsum panel (e.g. the surface 116 in FIG. 1) has a
finish from about a level 1 finish to about a level 5 finish. In
certain embodiments, the adhesive coating composition is applied
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 (535.7 g per lineal cm) at
22.2.degree. C. In certain embodiments, methods include applying a
membrane, such as the self-adhering membranes described herein, to
the substantially smooth outer surface of the membrane-ready gypsum
panel. For example, Table 4 shows exemplary coating specifics, film
thickness, and spread rate for the material coatings applied to the
gypsum sandwich structure.
TABLE-US-00004 TABLE 4 Material Coating Application Parameters Film
Thickness Coating Specifics Liq. Film Transfer Spread rate Wt/gal
Weight wt. g/ft.sup.2 efficiency ft.sup.2/gal gal/MSF lbs/MSF
Product (kg/L) solids (g/m.sup.2) (100% = max) (m.sup.2/l) (L/MSM)
(g/MSM) Curtain 9.94 50.45% 8.7 100 261.42 1.56 38.97 Coat 1 (1.19)
(28.54) (6.42) (5.91) (190.27) Curtain 11.13 57.21% 14.5 100 199.17
2.15 53.62 Coat 2 (1.33) (47.57) (4.89) (8.14) (261.79) DRC 11.79
58.54% 3.5 100 894.37 0.45 11.17 (1.41) (11.48) (21.95) (1.70)
(54.54) Airless 11.8 58.61% 3 100 1045.56 0.38 9.57 (1.41) (9.84)
(25.66) (1.44) (46.72) Airless 11.8 58.61% 6.8 100 461.28 0.87
21.69 (1.41) (22.31) (11.32) (3.29) (105.90) Airless 11.8 58.61%
15.4 100 203.68 1.96 49.11 (1.41) (50.52) (5.00) (7.42)
(239.78)
[0084] As shown in FIGS. 2 and 3, apparatus for fabricating
membrane-ready gypsum panels as described above are also provided.
In one embodiment, shown in FIG. 2, the apparatus 200 includes a
board line 202 for transporting a first fibrous mat 201A, a
depositing mechanism 203 configured to deposit a gypsum slurry 211
onto a surface of the first fibrous mat 201A, a conveyor 205
configured to deposit a second fibrous mat 201B 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. The
resulting gypsum sandwich structure 206, i.e., the gypsum slurry
between two fibrous mats, may be transported to a dryer 214 for
drying the gypsum sandwich structure. For example, the dryer 214
may be an oven operated at a temperature to heat and set the gypsum
slurry.
[0085] The apparatus also includes adhesive coating composition
applicator 210, which is configured to apply an adhesive coating
composition to the surface of the first fibrous mat opposite the
gypsum slurry, i.e., the outward-facing surface of the first
fibrous mat. The adhesive coating composition is applied to cover
the surface of the first fibrous mat to form a membrane-ready
gypsum panel 216 having a substantially smooth outer surface. In
certain embodiments, the first fibrous mat includes a mat coating
on the surface opposite the gypsum, such that the adhesive coating
composition is applied to the surface of the mat coating.
[0086] In certain embodiments, as shown in FIG. 2, the adhesive
coating composition applicator is configured to apply the adhesive
coating composition to the first fibrous mat before the gypsum
sandwich structure 206 is dried in dryer 214. In alternative
embodiments, as shown in FIG. 3, the adhesive coating composition
applicator 306 of apparatus 300 is configured to apply the adhesive
coating composition to the first fibrous mat after the gypsum
sandwich structure 302 is dried in dryer 314.
[0087] In certain embodiments, the apparatus includes a transfer
mechanism configured to overturn the gypsum sandwich structure 206
such that the outer surface of the first fibrous mat, i.e., the
surface opposite the gypsum, is exposed prior to application of the
adhesive coating composition. In certain embodiments, the apparatus
includes a cutting mechanism 204 to cut the continuous gypsum
sandwich structure into panels 206A having the desired dimensions.
In certain embodiments, a roller or a forming plate (not shown in
FIG. 2) compresses the sandwich assembly to the desired
thickness.
[0088] The dry ingredients from which the gypsum core is formed may
be pre-mixed and fed to a mixer 220, such as a pin mixer. Water and
other liquid constituents, such as soap, used in making the core
may be metered into the mixer 220 and combined with the desired dry
ingredients to form the aqueous gypsum slurry. The reinforcing
fiber may be added to the slurry in the mixer 220. Foam (e.g.,
soap) may be added to the slurry in the mixer 220 to control the
density of the resulting core and/or gypsum layers.
[0089] The gypsum slurry may be dispersed in the depositing
mechanism 203 through one or more outlets from the mixer 220 onto a
moving sheet (i.e., non-woven fibrous mat 201A), which is
indefinite in length and is fed from a roll thereof onto a board
line and advanced by the conveyor 205. In certain embodiments, the
fibrous mats have a basis weight, in the absence of the coating, of
about 2 pounds per 100 square feet (97.65 g/m.sup.2). The fibrous
mat may have a mat coating on what constitutes the bottom surface
of the mat as the mat is fed to the board line. As described above,
the mat coating may include a dried aqueous mixture of a filler and
a polymer latex adhesive. The basis weight of the mat coating may
be between about 3 and 6 pounds per 100 square feet (146.5-293.0
g/m.sup.2) of mat.
[0090] One stream of gypsum slurry may be discharged through an
outlet to provide a relatively thin layer of aqueous calcined
gypsum slurry 211 on the surface of the first fibrous mat 201A.
When used, the thin layer of gypsum slurry is somewhat denser than
the aqueous slurry of gypsum that is used to form the main portion
of the core of the gypsum board, which is dispensed from another
outlet. As shown schematically in FIG. 1, this higher density
region of the core may penetrate into the interstices of the
fibrous mat and help to form a strong bond between the lower
density portion of the core and the fibrous mat face. For example,
the first gypsum layer may be a densified gypsum layer having a
density about 15 to about 25 percent greater than the density of
the second gypsum layer. Another fibrous mat may be fed onto the
top of the gypsum slurry to form a gypsum sandwich structure.
[0091] The membrane ready gypsum panels may be used in conjunction
with a variety of different suitable membranes. In general,
suitable membranes provide air barrier and/or weather resistive
barrier properties. Examples of such suitable membranes include the
commercial membranes listed in Table 5, as well as any other
suitable membranes known in the art.
EXAMPLES
[0092] Embodiments of the membrane-ready gypsum panels disclosed
herein were constructed and tested for adhesive properties. The
results were compared to traditional self-adhering membranes
requiring on-site adhesive primer application.
[0093] Examples of comparative membrane/primer systems are listed
in Table 5 below. These systems require the outer surface of the
fibrous mats on the gypsum panel to be prepped with a solvent-based
or water-based adhesive primer before the membrane is overlaid and
applied directly to one of the exterior faces (e.g., walls, roof)
of the building. Traditional adhesive primers must be spray or
roller applied in the field after raw substrate installation and
before the air and moisture impermeable membrane is manually
applied to the surface of the fibrous mats and/or pressed with a
roller until the membrane is adhered.
[0094] The interfacial adhesion between the membrane and the raw
fibrous mat substrate is low, such that the primer is necessary and
the membrane cannot be adhered directly to the substrate. A raw
substrate of the fibrous mat can be very irregular at the membrane
interface, locally minimizing the actual contact of the membrane
with the board and leading to less than 1.0 lb/linear in (178.6
g/cm) adhesive strength that will not allow the membrane to stick
without a supplemental adhesive primer. Adhesive strength is
measured by the accepted peel strength test outlined in ASTM D903
at room temperature (RT), approximately 72.degree. F. (22.2.degree.
C.), and 35.degree. F. (1.7.degree. C.). Adhesion force data was
attained from AMETEK Test System 500 with 50LBF Module after the
asphalt membrane, 2 inches wide (5.08 cm), was roller applied onto
the coated board after 24 hours of conditioning at RT,
approximately 72.degree. F. (22.2.degree. C.), with an
approximately 3.5 pound (1588 g) roller.
[0095] The application coverage for the standard adhesive primers
is also high because the bare substrates soak up the adhesive,
thereby requiring significant amounts to reduce the Cobb value and
obtain the desired weathering properties. Application coverage
rates of traditional adhesive primers are given in table 6 below.
Field applied adhesive primer is not normally required with the
panels of the present invention. However, if one were to apply such
primers to the panels of the present invention, one would be
expected to use much lower amounts than listed in Table 6.
TABLE-US-00005 TABLE 5 Comparative Self Sealing Membrane/Adhesive
Primer Systems Company Adhesive Membrane Carlisle CCW-702 WIP 300
HT Carlisle CAV-GRIP WIP 200 Carlisle CCW AWP MiraDRI 860 Carlisle
CCW AWP MiraDRI 861 Henry Blueskin .RTM. Spray Adhesive BlueSkin SA
Henry Aquatac .TM. Primer BlueSkin LT Grace Perm-A-Barrier .RTM. WB
PermaBarrier Wall Membrane Grace Perm-A-Barrier .RTM. WB
PermaBarrier Wall Flashing
TABLE-US-00006 TABLE 6 Comparative Adhesive Primer Application
Rates Company Adhesive Application Rate Carlisle CCW AWP 400
ft.sup.2/gal (9.82 m.sup.2/l) Henry Blueskin .RTM. Spray Adhesive
125 to 250 ft.sup.2/gal (3.07-6.14 m.sup.2/l) Henry Aquatac .TM.
Primer 250-500 ft.sup.2/gal (6.14-12.27 m.sup.2/l) Grace
Perm-A-Barrier .RTM. 250-350 ft.sup.2/gal (6.14-8.59 m.sup.2/l)
[0096] Adhesive coating compositions as described in Tables 1, 2,
and 3 were prepared and applied to a DENS sheathing product,
commercially available from Georgia Pacific (Atlanta, Ga.), which
is a gypsum sandwich structure produced in accordance with the
methods described herein. For each of the adhesive coatings, the
following tests were performed, unless otherwise indicated: (1)
Block--two gypsum boards 6 in by 6 in (15.24 cm by 15.24 cm) were
placed face to back at 120.degree. F. (48.9.degree. C.)/20 PSI
(0.137 N/mm.sup.2)/2 hrs. The boards were tested while still hot
after applying and curing two coats at 2-4 mils wet and baked at
210.degree. F. (98.89.degree. C.) BST for 23 seconds per coat. The
test was considered passed when the boards freely release; and (2)
Adhesion--measured by the accepted peel strength test outlined in
ASTM D903 at room temperature (RT), approximately 72.degree. F.
(22.2.degree. C.), and 35.degree. F. (1.7.degree. C.). Adhesive
force data was attained from AMETEK Test System 500 with 50LBF
Module after the asphalt membrane, 2 inches wide (5.08 cm), was
roller applied onto the coated board after 24 hours of conditioning
at RT, approximately 72.degree. F. (22.2.degree. C.), with an
approximately 3.5 pound (1588 g) roller. The comparative sample was
a raw gypsum based substrate with no coatings applied to the
face.
[0097] The curtain coat applicator material coating compositions
(shown in Table 1) were prepared and had the properties shown in
Table 7.
TABLE-US-00007 TABLE 7 Curtain Coat Applicator Material Coating
Properties Coating Property Composition 1 Composition 2 Units
Solids 50.45 57.21 % NVM PVC 25.08 44.98 % VOC 0 0 g/l (--H.sub.2O
and Exempts) VHAP 0 0 g/l (--H.sub.2O and Exempts) Application
653.85 685.23 ft.sup.2/gal Rate (16.05) (16.82) (m.sup.2/l)
[0098] Coated boards, 4 in.times.11 in (10.2 cm by 27.9 cm) were
produced with two coats (8 mils wet each), air flashed for 5 min
and dried at 220.degree. F. (104.4.degree. C.) for 10 min. An
asphalt membrane, 2 in by 18 in (5.1 cm by 45.7 cm), was roller
applied onto the coated board after 24 hours of conditioning at RT.
A control panel with no adhesion had membrane applied directly to
the raw substrate. A second control panel included a solventborne
adhesive (Henry BLUESKIN Adhesive) applied at 8 mils each for two
coats and dried at RT for 30 min. For the Block test, two gypsum
boards, 6 in by 6 in (15.2 cm by 15.2 cm), were placed face to back
at 120.degree. F. (48.9.degree. C.) under 20 psi (0.137 N/mm.sup.2)
for 1 hour and 30 minutes after applying two coats at 8 mils
(.about.200 micron) each. The test results of the curtain coated
samples are given in Table 8.
TABLE-US-00008 TABLE 8 Curtain Coat Material Coatings Performance
for Adhesion (g/cm) Time 15 min 1 hour 48 hour Temperature 35 F. RT
35 F. RT 35 F. RT Coating Avg. .sigma. Avg. .sigma. Avg. .sigma.
Avg. .sigma. Avg. .sigma. Avg. .sigma. Block Control with No 0.0
0.0 44.6 26.8 0.0 0.0 53.6 17.9 0.0 0.0 44.6 8.9 Pass Adhesive
Control with 455.4 294.7 544.7 232.2 750.0 535.7 571.5 241.1 1125.1
455.4 678.6 276.8 NA Blueskin Adhesive Curtain Coat 375.0 285.7
535.7 214.3 705.4 535.7 562.5 232.2 1134.0 482.2 660.7 267.9 Pass
Composition 1 No Adhesive Curtain Coat 285.7 241.1 473.2 232.2
589.3 455.4 482.2 223.2 937.5 437.5 571.5 276.8 Pass Composition 2
No Adhesive
[0099] The direct roll coat (DRC) applicator material coating
compositions (shown in Table 2) were prepared and had the
properties shown in Table 9.
TABLE-US-00009 TABLE 9 DRC Applicator Material Coating Properties
Coating Property Composition 1 Units Solids 58.54 % NVM PVC 59.92 %
VOC 2.40 g/l (--H.sub.2O and Exempts) VHAP 1.20 g/l (--H.sub.2O and
Exempts) Application Rate 15.72 m.sup.2/L
[0100] A control was coated with a solventborne adhesive (Henry
BLUESKIN adhesive) at 6-8 mils each and dried at RT for 30 min. A
second control was prepared without a coating. For the Block test,
two coats at 2-4 mils wet were applied and baked at 210.degree. F.
(98.9.degree. C.) BST for 23 seconds per coat. The test results of
the direct roll coated samples are given in Table 10.
TABLE-US-00010 TABLE 10 DRC Material Coatings Performance for
Adhesion (g/cm) Time 15 min 1 hour 48 hour Temperature 35 F. RT 35
F. RT 35 F. RT Coating Avg. .sigma. Avg. .sigma. Avg. .sigma. Avg.
.sigma. Avg. .sigma. Avg. .sigma. Block Control with 89.3 35.7
526.8 44.6 89.3 44.6 508.9 71.4 80.4 44.6 875.0 142.9 NA Blueskin
Spray Adhesive Control No 0.0 0.0 44.6 26.8 0.0 0.0 53.6 17.9 0.0
0.0 44.6 8.9 Pass Adhesive DRC Variable No 348.2 71.4 660.7 44.6
330.4 80.4 678.6 53.6 696.5 125.0 821.5 267.9 Pass Adhesive
[0101] The airless applicator material coating compositions (shown
in Table 3) were prepared and had the properties shown in Table
11.
TABLE-US-00011 TABLE 11 Airless Applicator Material Coating
Properties Coating Property Composition 1 Units Solids 58.61 % NVM
PVC 59.75 % VOC 2.40 g VOC/l (--H.sub.2O and Exempt Solvents) VHAP
1.20 g VHaps/l (--H.sub.2O and Exempt Solvents) Application Rate
15.84 m.sup.2/L
[0102] A control was coated with a solventborne adhesive (Henry
BLUESKIN adhesive) at 6-8 mils each and dried at RT for 30 min.
Comparative samples were prepared using the DRC composition applied
with a Dubois direct roll coater run in DRC mode with a 40
durometer blue rubber roll at 85 KU (1 Pa-s) viscosity at
66.degree. F. (18.9.degree. C.), double passed wet-on-wet
application of 0.9 to 1.1 g/ft.sup.2 (9.7 to 11.8 g/m.sup.2) and
cured with IR heat to a 190.degree. F. (87.8.degree. C.) BST after
the first coat and 205.degree. F. (96.1.degree. C.) BST after the
second coat with burners at 70% intensity on 16'' (40.64 cm)
centers. The airless composition samples were prepared by applying
the airless composition with a 1226 tip and a 33 restrictor using a
single spray gun approximately 12'' (30.48 cm) above the board
surface and centered over the board as the material was sprayed in
a single pass application of 6 to 8 g/ft.sup.2 (64.6 to 81.6
g/m.sup.2), and curing the samples with IR heat to 205.degree. F.
(96.1.degree. C.) BST after two passes with burners at 70%
intensity on 16'' (40.64 cm) centers. The test results of the
airless coated samples are given in Table 12.
TABLE-US-00012 TABLE 12 Airless Material Coatings Performance for
Adhesion (g/cm) Time 15 min 1 hour 48 hour Temperature RT RT RT
Coating Avg. .sigma. Avg. .sigma. Avg. .sigma. Block Control with
Blueskin Spray Adhesive 1046.5 107.1 1107.2 125.0 1075.0 133.9 NA
DRC Composition with Blueskin Spray Adhesive 1044.7 142.9 1091.1
116.1 1139.3 116.1 Pass Airless Composition with Blueskin Spray
Adhesive 1432.2 35.7 2091.2 133.9 2953.7 160.7 Pass Airless
Composition with Blueskin Spray Adhesive 1355.4 80.4 2112.6 133.9
2846.5 366.1 Pass Control No Adhesive 94.6 53.6 100.0 26.8 78.6
17.9 NA DRC Composition No Adhesive 671.5 267.9 626.8 80.4 809.0
98.2 Pass Airless Composition with No Adhesive 921.5 89.3 1030.4
44.6 1087.5 17.9 Pass Airless Composition with No Adhesive 948.3
62.5 1037.5 66.1 1057.2 26.8 Pass
[0103] As can be seen from the above test results, the
membrane-ready gypsum panels displayed membrane adhesion properties
comparable, and often stronger, than the primed control samples.
The membrane-ready gypsum panels also display improved application
rates and simplify the panel/membrane installation process, thereby
increasing productivity and lowering installed system cost. The
membrane-ready gypsum panels also advantageously reduce or
eliminate high VOC primers on site. The membrane-ready gypsum
panels also display the necessary block resistant properties needed
for the panels to be stacked in preparation for shipping and
transportation.
[0104] Without intending to be bound by a particular theory, it is
believe that the material coating fills voids in the fibrous mesh,
thereby smoothing the surface, which facilitates increased adhesion
surface area between the gypsum panel face/back and the membrane
barrier. Additionally, the application of a material coating to a
fibrous faced gypsum panel can reduce adhesive/primer penetration
into the glass fiber mat and gypsum board, which as a result can
reduce or eliminate primer usage.
[0105] The membrane-ready gypsum panels disclosed herein may be
suitable for use in any applications where fibrous mats or other
glass mats are used, for example in roof boards, wall boards,
soffits, etc. The membrane-ready panels may also be suitable for
applications in which it is desirable to limit air infiltration
into a building, for example in health care and
educational/research and development settings.
[0106] Embodiments of the present disclosure further relate to any
one or more of the following paragraphs:
[0107] 1. A method of making an unattached, membrane-ready,
exterior gypsum panel, comprising: [0108] depositing a gypsum
slurry onto a surface of a first fibrous mat; [0109] 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;
[0110] drying the gypsum sandwich structure; [0111] 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
[0112] 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.
[0113] 2. The method of paragraph 1, wherein the first fibrous mat
has a mat coating on the surface of the first fibrous mat opposite
the gypsum slurry.
[0114] 3. The method of paragraph 1, wherein the second fibrous mat
has a mat coating on the surface of the second fibrous mat opposite
the gypsum slurry.
[0115] 4. The method of paragraph 1, wherein applying the adhesive
coating composition occurs after drying the gypsum sandwich
structure.
[0116] 5. The method of paragraph 1, wherein applying the adhesive
coating composition occurs before drying the gypsum sandwich
structure.
[0117] 6. The method of paragraph 1, wherein applying the adhesive
coating composition comprises spray coating, ribbon coating, or
direct roll coating the adhesive coating on the surface of the
first fibrous mat opposite the gypsum slurry.
[0118] 7. The method of paragraph 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.
[0119] 8. The method of paragraph 1, wherein the adhesive coating
composition contains solids in an amount from about 35 to about 100
weight percent.
[0120] 9. The method of paragraph 1, wherein the adhesive coating
composition comprises a polymeric adhesive comprising at least one
of a latex polymer, a water-dispersible polymer, a water-reducible
polymer, or an oil-modified polymer.
[0121] 10. The method of paragraph 9, wherein the polymeric
adhesive comprises a polymer selected from acrylics, styrene
acrylics, vinyl acrylics, styrene acetate acrylics, and
combinations thereof.
[0122] 11. The method of paragraph 10, wherein the polymeric
adhesive comprises a polymer or a copolymer with a glass transition
temperature of 0 to 30.degree. C.
[0123] 12. The method of paragraph 1, wherein depositing a gypsum
slurry comprises: [0124] depositing a first gypsum slurry onto the
surface of the first fibrous mat; and [0125] depositing a second
gypsum slurry onto the first gypsum slurry, the second gypsum
slurry having a lower density than the first gypsum slurry.
[0126] 13. The method of paragraph 1, further comprising: [0127]
attaching the membrane-ready gypsum panel to a building; and [0128]
applying a membrane to the substantially smooth outer surface of
the membrane-ready gypsum panel.
[0129] 14. The method of paragraph 13, wherein the membrane
comprises WIP 300 HT, WIP 200, MiraDRI 860, MiraDRI 861, Blueskin
SA, Blueskin LT, PermaBarrier Wall membrane, or PermaBarrier Wall
flashing.
[0130] 15. The method of paragraph 1, wherein the adhesive coating
composition is applied 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.degree.
F. (535.7 g/cm at 22.2.degree. C.).
[0131] 16. The method of paragraph 1, wherein the first fibrous mat
is a fiberglass mat.
[0132] 17. The method of paragraph 1, wherein the first fibrous mat
is paper.
[0133] 18. An apparatus for fabricating membrane-ready gypsum
panels, comprising: [0134] a board line for transporting a first
fibrous mat; [0135] a depositing mechanism configured to deposit a
gypsum slurry onto a surface of the first fibrous mat; [0136] 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; [0137] a dryer
for drying the gypsum sandwich structure; [0138] 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 [0139] 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.
[0140] 19. The apparatus of paragraph 18, wherein the applicator is
configured to apply the adhesive coating composition to the first
fibrous mat before the gypsum sandwich structure is dried.
[0141] 20. The apparatus of paragraph 18, wherein the applicator is
configured to apply the adhesive coating composition to the first
fibrous mat after the gypsum sandwich structure is dried.
[0142] 21. The apparatus of paragraph 18, 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.
[0143] 22. A membrane-ready gypsum panel, comprising: [0144] a
first fibrous mat having a first surface and a second surface;
[0145] a second fibrous mat having a first surface and a second
surface; [0146] a gypsum core in contact with the second surfaces
of the first and second fibrous mats; and [0147] 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.
[0148] 23. The membrane-ready gypsum panel of paragraph 22, wherein
the material coating is derived from an adhesive coating
composition comprising a polymeric adhesive, wherein the polymeric
adhesive comprises an aqueous emulsion selected from acrylics,
styrene acrylics, vinyl acrylics, styrene acetate acrylics, and
combinations thereof.
[0149] 24. The membrane-ready gypsum panel of paragraph 22, wherein
the outer surface of the material coating has a finish from about a
level 1 finish to about a level 5 finish.
[0150] 25. The membrane-ready gypsum panel of paragraph 22, wherein
the gypsum core comprises: [0151] a first gypsum layer in contact
with the second surface of the first fibrous mat; and [0152] 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.
[0153] 26. The membrane-ready gypsum panel of paragraph 22, wherein
the membrane-ready gypsum panel has a Cobb value below 5 grams.
[0154] 27. The membrane-ready gypsum panel of paragraph 22, wherein
the membrane-ready gypsum panel has a vapor permeance equal to or
greater than 1.5 perms.
[0155] 28. The membrane-ready gypsum panel of paragraph 22, 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).
[0156] 29. The membrane-ready gypsum panel of paragraph 22, 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.degree. F. (535.7 g/cm at 22.2.degree.
C.).
[0157] 30. The membrane-ready gypsum panel of paragraph 22, wherein
the first and second fibrous mats each comprise a non-woven fibrous
mat comprising glass fibers.
[0158] 31. The membrane-ready gypsum panel of paragraph 22, wherein
the first and second fibrous mats each comprise paper.
[0159] 32. The membrane-ready gypsum panel of paragraph 30, wherein
the glass fibers have an average diameter from about 10 to about 17
microns and an average length from about one-quarter (1/4) inch to
about three-quarter (3/4) inch (0.64 to 1.91 cm).
[0160] 33. The membrane-ready gypsum panel of paragraph 22, wherein
the mats further comprise a mat coating on a surface thereof,
wherein the mat coating comprises a filler and an adhesive
binder.
[0161] 34. A method for coating an unattached, exterior gypsum
wallboard to make the wallboard membrane-ready, comprising the
steps of: [0162] 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 [0163] 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.
[0164] 35. The method of paragraph 34, further comprising: [0165]
attaching the membrane-ready gypsum wallboard to a building; and
[0166] applying a membrane to the substantially smooth outer
surface of the membrane-ready gypsum panel without a field-applied
adhesive.
[0167] 36. The method of paragraph 35, wherein the membrane
comprises WIP 300 HT, WIP 200, MiraDRI 860, MiraDRI 861, Blueskin
SA, Blueskin LT, PermaBarrier Wall membrane, or PermaBarrier Wall
flashing.
[0168] 37. The method of paragraph 35, wherein the membrane has a
peel strength of above 3 pounds per linear inch at 72.degree. F.
(535.7 g/cm at 22.2.degree. C.).
[0169] While the disclosure has been described with reference to a
number of embodiments, it will be understood by those skilled in
the art that the invention is not limited to such disclosed
embodiments. Rather, the invention can be modified to incorporate
any number of variations, alterations, substitutions, or equivalent
arrangements not described herein, but which are commensurate with
the spirit and scope of the invention. Additionally, while various
embodiments of the invention have been described, it is to be
understood that aspects of the invention may include only some of
the described embodiments. Accordingly, the invention is not to be
seen as limited by the foregoing description, but is only limited
by the scope of the appended claims.
* * * * *