U.S. patent application number 10/322433 was filed with the patent office on 2004-06-24 for flame-resistant insulation.
This patent application is currently assigned to CERTAINTEED CORPORATION. Invention is credited to Toas, Murray S..
Application Number | 20040121152 10/322433 |
Document ID | / |
Family ID | 32592992 |
Filed Date | 2004-06-24 |
United States Patent
Application |
20040121152 |
Kind Code |
A1 |
Toas, Murray S. |
June 24, 2004 |
Flame-resistant insulation
Abstract
Flame-resistant insulation may be prepared by coating a glass
fiber substrate, such as a fiberglass board, with an aqueous
dispersion of vermiculite and expandable graphite. The insulation
may also be pre-coated with a vermiculite dispersion prior to
coating with a vermiculite/expandable graphite coating, and the
vermiculite/expandable graphite coating may be covered with an FSK
facing, or with a gypsum or portland cement layer. The resulting
coated insulation board has superior flame resistance, and may be
used as a component of a building or in vehicles.
Inventors: |
Toas, Murray S.;
(Norristown, PA) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
CERTAINTEED CORPORATION
Valley Forge
PA
|
Family ID: |
32592992 |
Appl. No.: |
10/322433 |
Filed: |
December 19, 2002 |
Current U.S.
Class: |
428/374 ;
428/388 |
Current CPC
Class: |
C04B 30/02 20130101;
C04B 41/65 20130101; C04B 30/02 20130101; C04B 2111/285 20130101;
C09K 21/02 20130101; C04B 30/02 20130101; Y10T 428/2956 20150115;
C04B 41/5001 20130101; C04B 41/5001 20130101; C04B 41/009 20130101;
Y10T 428/2931 20150115; C04B 41/70 20130101; C04B 41/4539 20130101;
C04B 41/4539 20130101; C04B 41/009 20130101; C04B 41/52 20130101;
C04B 41/52 20130101; C04B 41/52 20130101; C04B 41/0072 20130101;
C04B 41/5001 20130101; C04B 24/302 20130101; C04B 14/42 20130101;
C04B 41/4539 20130101; C04B 41/0072 20130101; C04B 14/202 20130101;
C04B 30/02 20130101; C04B 7/02 20130101; C04B 14/202 20130101; C04B
14/202 20130101; C04B 14/42 20130101 |
Class at
Publication: |
428/374 ;
428/388 |
International
Class: |
D02G 003/00 |
Claims
What is claimed as new and is intended to be secured by Letters
Patent is:
1. Flame and heat-resistant insulation comprising a glass fiber
substrate coated with a mixture comprising vermiculite and
expandable graphite.
2. The flame and heat-resistant insulation of claim 1, wherein the
weight ratio of vermiculite to expandable graphite in the coating
is in the range of 10:1 to 1:10.
3. The flame and heat-resistant insulation of claim 1, wherein the
mixture further comprises an organic binder.
4. The flame and heat-resistant insulation of claim 1, wherein the
mixture further comprises an inorganic binder.
5. The flame and heat-resistant insulation of claim 1, wherein the
coating has a dry weight of 5 to 30 g/100 in.sup.2.
6. The flame and heat-resistant insulation of claim 1, wherein the
coating has a dry weight of 10 to 30 g/100 in.sup.2.
7. The flame and heat-resistant insulation of claim 1, wherein an
FSK facing is adhered to the coating.
8. The flame and heat-resistant insulation of claim 1, wherein a
cement layer is deposited on the coating.
9. The flame and heat-resistant insulation of claim 1, wherein a
gypsum layer is deposited on the coating.
10. The flame and heat-resistant insulation of claim 1, wherein
said glass fiber substrate is selected from the group consisting of
a glass fiber flexible mat, a glass fiber fabric, a glass fiber
sheet, and a glass fiber board.
11. The flame and heat-resistant insulation of claim 10, wherein
the glass fiber substrate is a glass fiber board.
12. The flame and heat-resistant insulation of claim 11, wherein
the board has a density of 2.5 to 6 lb/ft.sup.3.
13. A method of preparing the flame and heat-resistant insulation
of claim 1, wherein a mixture comprising vermiculite and expandable
graphite are dispersed in water, said dispersion is coated onto a
glass fiber substrate, and dried.
14. The method of claim 13, wherein said depositing is selected
from the group consisting of spraying, roller coating, gravure
coating, curtain coating, slot-die coating and brushing.
15. A door panel comprising the flame and heat-resistant insulation
of claim 1.
16. A wall comprising the flame and heat-resistant insulation of
claim 1.
17. A building insulation comprising the flame and heat-resistant
insulation of claim 1.
18. A vehicle insulation comprising the flame and heat-resistant
insulation of claim 1.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to flame and heat-resistant
insulation, a process for making the insulation flame-resistant,
and a method of protecting insulation from the effects of fire. The
flame-resistant insulation of the present invention comprises
insulation coated with a mixture comprising vermiculite and
expandable graphite.
[0003] 2. Discussion of the Background
[0004] Insulating materials are commonly used in the fabrication of
components of buildings, such as doors, walls, ceilings and roofs,
or in vehicles such as automobiles, trucks, aircraft, and ships.
Insulating materials are commonly made of inorganic fibers, such as
glass or mineral fibers, in order to provide a degree of
fire-resistance. Preferably, the fibers comprise a glass.
[0005] The majority of glass fiber products used in insulating
materials are composed of either sodium borosilicate glass having a
softening point of approximately 1290.degree. F. or E-type
borosilicate glass having a softening point as low as about
1529.degree. F. More refractory glass fibers are also known, such
as aluminosilicate S-glass, but these higher melting point glass
fibers are relatively expensive, and therefore are unsuitable for
low cost applications, such as building insulation, and are used
primarily in specialty applications where the higher melting point
of these fibers is critical.
[0006] Although glass or mineral fiber insulation materials have
superior flame resistance compared to insulation materials based on
flammable fibers (e.g., lignocellulose derived fibers), glass
insulation materials have only modest flame and heat resistance
because of their relatively low melting point. When exposed to
flames, glass fiber insulation materials melt, thereby allowing
flames and heat to penetrate through the insulation material, and
consequently allowing the fire to spread. It is therefore desirable
to enhance the flame and heat resistance of glass fiber-based
insulation materials.
[0007] Re. 34,020 describes a fibrous composite material that is
coated with a lamellar material such as vermiculite to enhance the
fire-resistance of the material. While the fire-resistance of the
coated fiberglass material is enhanced, the flame-retardancy and
thermal insulation properties of the resulting composite are still
inadequate.
[0008] U.S. Pat. No. 4,888,233 describes fire-resistant composite
materials prepared by coating a polymeric substrate with a mixture
of chemically delaminated vermiculite and a copolymer of ethylene
and a vinyl monomer. While this coating decreases the flammability
of the polymeric substrate, improved flame and heat resistance is
still desirable.
[0009] U.S. Pat. No. 5,968,669 describes a fire-retardant coating
for lignocellulosic materials which comprises a mixture of
expandable graphite particles, an absorbent material such as
calcium carbonate to absorb toxic gases, a polymeric binder, a
"carbonific" material such as pentaerythritol, which forms a
network binding expanded units of expandable graphite together, a
blowing agent to generate an intumescent char foam, and a wetting
agent to improve wetting of the coating onto the substrate.
However, U.S. Pat. No. 5,968,669 only describes coated
lignocellulose-based materials, and the resulting coated articles,
while flame-resistant compared to uncoated lignocellulose-based
materials, are still flammable.
[0010] U.S. Pat. No. 5,972,434 describes fire-resistant glass fiber
products coated with a nitrogen-containing compound and a
boron-containing compound, which upon exposure to fire or high
temperatures react with each other to form a refractory compound on
the surface of the fibers.
[0011] However, there is still a need to provide inexpensive
insulating materials having improved flame and heat resistance.
SUMMARY OF THE INVENTION
[0012] Accordingly, it is an object of the present invention to
provide an improved flame and heat resistant insulating material
comprising glass fibers coated with a mixture comprising
vermiculite and expandable graphite. A second object of the present
invention is to provide a method of preparing such flame-resistant
insulation. A third object of the present invention is to provide a
method of protecting insulation with a coating comprising
vermiculite and expandable graphite.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The insulation of the present invention comprises a glass
fiber substrate coated with a mixture comprising vermiculite and
expandable carbon. The substrate may include products formed from
at least one layer of fibers. The fiber layers may comprise loose
fibers, or may be woven, knitted, needle punched, felted, or
otherwise combined in various ways to provide a unified structure.
The fibers may be continuous, filamentary fibers, or discontinuous,
staple fibers or agglomerations of such fibers. The fibers may
comprise any conventional glass fiber commonly used in insulation
products, including an E-glass, a C-glass, or a high boron content
C-glass.
[0014] The fibrous substrate may be flexible or rigid. For example,
the fibrous substrate may be a flexible batt, mat, blanket, fabric,
or sheet, or a rigid slab or board. The density of the fibrous
substrate may range from 1.0 lb/ft.sup.3 to 10 lb/ft.sup.3,
including 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5,
8, 8.5, 9, and 9.5 lb/ft.sup.3, inclusive of all values and
subranges therebetween. If the substrate is a rigid board, the
density is preferably 2.5 to 6 lb/ft.sup.3. The substrate may be as
thin as 1/2 inch or as thick as two inches, preferably 1 to 2
inches thick.
[0015] A binder may be used to capture and hold the fibers of the
fibrous substrate together. The binder can be organic or inorganic.
The binder can be a thermosetting polymer, a thermoplastic polymer,
or a combination of both thermoplastic and thermosetting-polymers.
Preferably, the thermosetting polymer is a phenolic resin, such as
a phenol-formaldehyde resin, which will cure or set upon heating.
When binder is used in the insulation product, the amount of binder
can be from 1 to 30 wt %, preferably from 3 to 25 wt %, more
preferably from 6 to 18 wt %.
[0016] The fibrous substrate may be composed only of glass fibers,
or may have at least one additional layer laminated thereto. The
additional layer may include a woven or non-woven fiberglass fabric
layer, or may be a FSK (foil-scrim-kraft) sheet glued onto the
surface, a gypsum cement layer, or a quick-set cement layer. For
example, the quick-set cement layer may be a conventional Portland
type cement product. The gypsum cement may be any cementitious
material containing gypsum. These coatings can be applied to one or
both surfaces of the fiberglass substrate.
[0017] The coating of the present invention, which is applied to
the substrate, comprises a dispersion of vermiculite mixed with
expandable graphite. The vermiculite may include the minerals known
both scientifically and commercially as vermiculite, including the
chloride-vermiculites. For example, the vermiculite may be any
naturally occurring micaceous hydrated magnesium-aluminum-silicate
which has been chemically delaminated, for example by dispersing
the vermiculite in an aqueous solution containing cations such as
alkylammonium cations, and lithium cations. Particularly effective
vermiculite dispersions include MicroLite.RTM. dispersions (W.R.
Grace & Company). The dispersion of vermiculite may consist of
only the chemically delaminated vermiculite and water, but may also
include vermiculite dispersions which include a small amount of an
organic binder or other additives to stabilize the dispersion and
facilitate coating and adhesion to the fibrous substrate (e.g.,
dispersing agents or organic adhesion promoters). The dispersion of
vermiculite may have as low as 1% solids, or levels as high as 50%
solids. Solids contents of approximately 5 to 25%, more preferably
10 to 20%, most preferably approximately 16.5% are desirable.
[0018] Any conventional type of expandable graphite may be used.
Expandable graphite differs from other forms of graphite in that it
is specially treated to expand in volume upon heating. In order to
become expandable, the graphite may be treated, for example, with
sulphuric acid in order to intercalate sulphuric acid between the
layers of the graphite. The treated graphite is then washed and
dried, providing a dry pourable material. Upon heating, the
intercalated material, e.g., sulphuric acid, volatilizes between
the graphite layers, thereby expanding the volume of the graphite
flake. The high volume provided by this expansion provides an
insulative layer which reduces heat transfer through the material,
mass loss, and reduces the generation of smoke.
[0019] The volume expansion of the expandable graphite may be up to
100 times the original thickness of the flake, depending on the
specific type and amount of intercalant used. The percent expansion
is typically in the range of 50 to 250% by volume, depending upon
the amount of intercalant added to the graphite. The onset
temperature of the expansion typically occurs at temperatures
between 230.degree. C. and 280.degree. C. Suitable particle sizes
are in the range of 50 to 220 mesh.
[0020] The relative amounts of vermiculite and expandable graphite
in the coatings of the present invention may range from 10:1 to
1:10 (dry weight of vermiculite: dry weight of expandable
graphite). The preferred ratio of vermiculite to expandable
graphite is 5:1 to 1:5, more preferably 3:1 to 1:3, most preferable
approximately 2:1. The total solids content of the coating of the
present invention, prior to application, may be approximately 15 to
60 wt. %, preferably from 15 to 50 wt. %, more preferably from 15
to 30 wt. %.
[0021] The coating may be prepared by mixing an aqueous dispersion
of vermiculite, optionally containing dispersing agents, binders,
and adhesion promoters, with an aqueous dispersion of expandable
graphite, or dry expandable graphite. Alternatively, the
vermiculite and expandable graphite may be mixed as dry powders,
and then dispersed in water using conventional dispersing
equipment. The coating of the present invention may be coated onto
the substrate by any conventional method such as brushing,
spraying, roller coating, gravure coating, curtain coating, and
slot-die coating.
[0022] The coating of the present invention may be applied as a
single coating to the substrate, or applied in two or more coating
steps. In addition, a coating of vermiculite or expandable graphite
may be applied to the substrate, prior to coating with the mixture
of vermiculite and expandable graphite. The coating may be
air-dried, or oven-dried. The dry weight of the coating may be 5 to
30 g/100 in.sup.2, preferably 10 to 30 g/100 in.sup.2, more
preferably 15 to 30 g/100 in.sup.2, most preferably 15 to 25 g/100
in.sup.2.
EXAMPLES
[0023] The flame and heat-resistance of insulation boards, both
coated and uncoated with the coating composition of the present
invention, were tested for flame resistance in the following
manner. The coated board was mounted horizontally above a Bunsen
burner flame so that the coated surface of the board was exposed
directly to a flame having an approximate flame temperature of
1750.degree. F. The temperature of the board was measured over a
one hour period at the middle of the thickness of the board,
directly above the flame, and the opposing surface of the board
directly above the flame (i.e., the surface opposite the side
directly exposed to the flame). The maximum temperature measured at
the center of the thickness of the board (i.e., the maximum center
of thickness temperature) and the maximum temperature at the top
surface (i.e., the maximum top surface temperature) were measured
for one hour after exposing the board to the flame. Lower
temperatures are indicative of better flame and
heat-resistance.
Example 1
[0024] A 4.8 lb/ft.sup.3 fiberglass insulation board
(ULTRADUCT.TM., CertainTeed), having a thickness of 1 inch was
coated with a mixture of MicroLite.RTM. HTS vermiculite dispersion
(W. R. Grace) and MYZR802 expandable graphite (Hebei Maoyuan
Chemical Industry Company of China) in a weight ratio of 2:1
vermiculite:expandable graphite, and a solids content of 17.2 wt.
%. The mixture was painted onto one surface of the board using a
paint brush, and after air drying for 48 hours, had a dry weight of
18.7 g/100 in.sup.2. After exposure to a Bunsen burner flame, as
described above, the maximum center thickness temperature was
666.degree. F. and the maximum top surface temperature was
424.degree. F. The surface of the board was somewhat discolored by
exposure to the flame, but no obvious melting of the glass fibers
was observed.
Example 2
[0025] A 4.6 lb/ft.sup.3 fiberglass insulation board was coated as
in Example 1, above, except that the solids content of the coating
mixture was 46.9 wt. %, and dry weight of the coating was 21.3
g/100 in.sup.2. After exposure to a Bunsen burner flame, the
maximum center thickness temperature was 476.degree. F. and the
maximum top surface temperature was 488.degree. F.
Example 3
[0026] A 4.3 lb/ft.sup.3 fiberglass insulation board, as in Example
1, was first coated with MicroLite.RTM. HTS vermiculite dispersion
(16.4 wt. % vermiculite), and dried for 24 days, thereby forming a
vermiculite film having a dry weight of 6 g/100 in.sup.2. A coating
of a 2:1 mixture (by weight) of a MicroLite.RTM. HTS vermiculite
dispersion and MYZR802 expandable graphite (solids content 47.5 wt.
%), was then applied over the vermiculite film and dried for 12
days. The coating of the mixture of vermiculite and expandable
graphite had a dry weight of 15.1 g/100 in.sup.2. The coated board
was then exposed to a flame, as in Example 1. The maximum center
thickness temperature was 698.degree. F. and the maximum top
surface temperature was 348.degree. F. The surface of the board was
somewhat discolored by exposure to the flame, but no obvious
melting of the glass fibers was observed.
Example 4
[0027] A 4.5 lb/ft.sup.3 fiberglass insulation board was first
coated with a MicroLite.RTM. HTS vermiculite dispersion (16.1 wt. %
vermiculite), then coated with a mixture of MicroLite.RTM. HTS
vermiculite and MYZR802 expandable graphite (weight ratio of 2:1;
solids content of 46.9 wt. %) as in Example 3, above. The dry
weight of the vermiculite coating was 5.2 g/100 in.sup.2 and the
dry weight of the vermiculite/expandable graphite coating was 14.4
g/100 in.sup.2. After exposure to a flame, the maximum center
thickness temperature was 382.degree. F. and the maximum top
surface temperature was 426.degree. F.
Example 5
[0028] A 4.7 lb/ft.sup.3 fiberglass insulation board, as in Example
1, was coated with a mixture of MicroLite.RTM. HTS vermiculite and
MYZR802 expandable graphite (weight ratio 2:1; solids content of
45.3 wt. %). After dryng for 10 days, the coating had a dry weight
of 18.7 g/100 in.sup.2. A 6.4 g FSK facing (COMPAC FB30) having a
dry weight of 7.3 g/100 in.sup.2 (0.9 grams of dry glue) was
applied over the vermiculite/expandable graphite coating with a
water-based polyvinyl acetate type adhesive manufactured by Henkel
Corporation. The side of the board having the FSK facing was then
exposed to a Bunsen burner flame, as described above. The maximum
center of thickness temperature was 584.degree. F., and the maximum
top surface temperature was 449.degree. F. The FSK facing was
melted and distorted by the expansion of the expandable graphite,
but no melting of the glass fibers was observed.
Example 6
[0029] A 4.5 lb/ft.sup.3 fiberglass insulation board was first
coated with a mixture of MicroLite.RTM. HTS vermiculite and MYZR802
expandable graphite (weight ratio 2:1; solids content of 45.6 wt.
%), then covered with a FSK facing as described in Example 5,
above. The dry weight of the vermiculite/expandable graphite
coating was 16.9 g/100 in.sup.2 and the dry weight of the FSK
facing and adhesive (6.1 g facing; 2.4 g adhesive) was 8.5 g/100
in.sup.2. After exposure to a Bunsen burner flame, the maximum
center thickness temperature was 756.degree. F., and the maximum
top surface temperature was 366.degree. F.
Example 7
[0030] A 4.4 lb/ft.sup.3 fiberglass insulation board was first
coated with mixture of MicroLite.RTM. HTS vermiculite and MYZR802
expandable graphite (2:1 weight ratio; solids content of 48.5 wt.
%), air dried for 10 days, then coated with a layer of gypsum. The
gypsum was allowed to cure for 72 hours. The dry weight of the
vermiculite/expandable graphite coating was 19.2 g/100 in.sup.2 and
the dry weight of the gypsum cement coating was 71 g/100 in.sup.2.
After exposure to a Bunsen burner flame, the maximum center of
thickness temperature was 645.degree. F., and the maximum top
surface temperature was 368.degree. F. The gypsum layer flaked off
of the surface of the board, and the surface of the board was
somewhat discolored by exposure to the flame, but no obvious
melting of the glass fibers was observed.
Example 8
[0031] A 4.8 lb/ft.sup.3 fiberglass insulation board was first
coated with a mixture of MicroLite.RTM. HTS vermiculite and MYZR802
expandable graphite (weight ratio 2:1; solids content of 52.5 wt.
%), as in Example 7, dried for 10 days, and then coated with a
layer of quick-set cement. The quick-set cement was allowed to cure
for 72 hours. The dry weight of the vermiculite/expandable graphite
layer was 23.2 g/100 in.sup.2, and the dry weight of the quick-set
cement was 56.4 g/100 in.sup.2. After exposure to a Bunsen burner
flame, the maximum center of thickness temperature was 636.degree.
F., and the maximum top surface temperature was 454.degree. F. The
quick-set cement layer flaked off of the surface of the board where
it was exposed to the flame, and the board was somewhat discolored
by exposure to the flame, but no obvious melting of the glass
fibers was observed.
Example 9
[0032] A 4.5 lb/ft.sup.3 fiberglass insulation board was first
coated with a mixture of MicroLite.RTM. HTS vermiculite and MYZR802
expandable graphite (weight ratio 1:1; solids content of 42.7 wt.
%), and dried for 10 days. The dry weight of the
vermiculite/expandable graphite coating was 16.6 g/100 in.sup.2.
After exposure to a Bunsen burner flame, the maximum center of
thickness temperature was 900.degree. F., and the maximum top
surface temperature was 434.degree. F. The coating was notably
expanded where the flame contacted the board, but no melting of the
glass fibers was observed.
Example 10
[0033] A 4.6 lb/ft.sup.3 fiberglass insulation board was first
coated with a mixture of MicroLite.RTM. HTS vermiculite and MYZR802
expandable graphite (weight ratio 3:1; solids content of 36.6 wt.
%), and dried for 10 days. The dry weight of the
vermiculite/expandable graphite coating was 14.1 g/100 in.sup.2.
After exposure to a Bunsen burner flame, the maximum center of
thickness temperature was 1144.degree. F., and the maximum top
surface temperature was 442.degree. F. The coating was notably
expanded where the flame contacted the board, but no melting of the
glass fibers was observed.
Example 11
[0034] A 4.6 lb/ft.sup.3 fiberglass insulation board was first
coated with a mixture of MicroLite.RTM. HTS vermiculite and MYZR802
expandable graphite (weight ratio 5:1; solids content of 29.9 wt.
%), and dried for 10 days. The dry weight of the
vermiculite/expandable graphite coating was 10.5 g/100 in.sup.2.
After exposure to a Bunsen burner flame, the maximum center of
thickness temperature was 682.degree. F., and the maximum top
surface temperature was 367.degree. F. The coating was notably
expanded where the flame contacted the board, but no melting of the
glass fibers was observed.
Example 12
[0035] A 4.6 lb/ft.sup.3 fiberglass insulation board was first
coated with a mixture of MicroLite.RTM. HTS vermiculite and MYZR802
expandable graphite (weight ratio 10:1; solids content of 22.9 wt.
%), and dried for 10 days. The dry weight of the
vermiculite/expandable graphite coating was 8.2 g/100 in 2. After
exposure to a Bunsen burner flame, the maximum center of thickness
temperature was 796.degree. F., and the maximum top surface
temperature was 385.degree. F. The coating was notably expanded
where the flame contacted the board, but no melting of the glass
fibers was observed.
Comparative Example 1
[0036] An uncoated 4.6 lb/ft.sup.3 fiberglass insulation board,
which was otherwise identical to the insulation boards which were
coated in Examples 1-8, above, was exposed to a Bunsen burner
flame. The maximum center of thickness temperature was 972.degree.
F., and the maximum top surface temperature was 794.degree. F. The
board was discolored, and the glass fibers were melted nearly
through the thickness of the board, where exposed to the flame.
Comparative Example 2
[0037] A 4.96 lb/ft.sup.3 fiberglass insulation board was coated
with a dispersion of MicroLite.RTM. HTS vermiculite (solids content
of 17.2 wt. %). The dry weight of the vermiculite coating was 5.6
g/100 in.sup.2. After exposure to a Bunsen burner flame, the
maximum center of thickness temperature was 800.degree. F., and the
maximum top surface temperature was 673.degree. F. The surface of
the board was somewhat discolored by exposure to the flame, and the
glass fibers were melted to a depth of approximately half of the
thickness of the board where exposed to the flame.
Comparative Example 3
[0038] A 4.5 lb/ft.sup.3 fiberglass insulation board was coated
with a dispersion of MicroLitee HTS vermiculite (solids content of
17.0 wt. %). The dry weight of the vermiculite coating was 5.9
g/100 in.sup.2. After exposure to a Bunsen burner flame, the
maximum center of thickness temperature was 982.degree. F., and the
maximum top surface temperature was 631.degree. F.
[0039] As shown in the above Examples (Summarized in Table 1,
below), a glass fiber insulation board coated with a mixture of
vermiculite and expandable carbon provides significantly better
flame and heat resistance compared to uncoated insulation, or
insulation coated with vermiculite alone
1TABLE 1 Horizontal Insulation board exposed to a Bunsen burner
flame - approximately 1750.degree. F. Maximum Maximum Center of Top
Dry weight Thickness Surface of Treat- Tempera- Tempera- ment for
ture ture 100 square within within Description inch board 1 hour 1
hour Examples 1 2:1 by Weight HTS Vermicu- 18.7 666 424 lite:
Expandable Graphite 2 2:1 by Weight HTS Vermicu- 21.3 476 488 lite:
Expandable Graphite 3 1) HTS Vermiculite 6 698 348 2) 2:1 by Weight
HTS Ver- 15.1 miculite: Expandable Graphite 4 1) HTS Vermiculite
5.2 382 426 2) 2:1 by Weight HTS Ver- 14.4 miculite: Expandable
Graphite 5 1) 2:1 by Weight HTS Ver- 18.7 584 449 miculite:
Expandable Graphite 2) 6.4 g FSK facing applied 7.3 with Henkel
glue 6 1) 2:1 by Weight HTS Ver- 16.9 756 366 miculite: Expandable
Graphite 2) 6.1 g FSK facing applied 8.5 with Henkel glue 7 1) 2:1
by Weight HTS Ver- 19.2 645 368 miculite: Expandable Graphite 2)
Gypsum (43 g cement 21 g 71 H2O) 8 1) 2:1 by Weight HTS Ver- 23.2
636 454 miculite: Expandable Graphite 2) Quick Set Cement (90 g
56.4 cement 17.5 g H2O) 9 1:1 by Weight HTS Vermicu- 16.6 900 434
lite: Expandable Graphite 10 3:1 by Weight HTS Vermicu- 14.1 1144
442 lite: Expandable Graphite 12 5:1 by Weight HTS Vermicu- 10.5
682 367 lite: Expandable Graphite 13 10:1 by Weight HTS Ver- 8.2
796 385 miculite: Expandable Graphite Comparative Examples: 1
Untreated Board 972 794 2 HTS Vermiculite 5.6 800 673 3 HTS
Vermiculite 5.9 982 631
[0040] Obviously, numerous modifications and variations on the
present invention are possible in light of the above teachings. It
is therefore to be understood that within the scope of the appended
claims, the invention may be practice otherwise and as specifically
described herein.
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