U.S. patent application number 11/089058 was filed with the patent office on 2005-07-28 for compression molded inorganic fiber articles, and methods and compositions used in molding same.
This patent application is currently assigned to HON Technology Inc.. Invention is credited to Lyons, David Charles, Schroeder, Ted Victor.
Application Number | 20050165160 11/089058 |
Document ID | / |
Family ID | 25121838 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050165160 |
Kind Code |
A1 |
Lyons, David Charles ; et
al. |
July 28, 2005 |
Compression molded inorganic fiber articles, and methods and
compositions used in molding same
Abstract
A method of forming articles made of an inorganic fiber material
using compression molding. In one respect, a method of forming an
article, wherein the method includes providing a molding
composition comprising inorganic fiber and an inorganic binder, and
compression molding the molding composition into the article. In
another respect, the method including providing a molding
composition comprising inorganic fibers and a binder, and
compression molding the molding composition into the article,
wherein at least 75% by weight of the molded article is inorganic
material. In some embodiments the cured binder is capable of
withstanding temperatures of at least 600.degree. F. without
significant degradation or deterioration due to heat. Articles made
by the use of such methods and a molding composition for use in
compression molding an article are also included.
Inventors: |
Lyons, David Charles; (Red
Wing, MN) ; Schroeder, Ted Victor; (Welch,
MN) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
HON Technology Inc.
Muscatine
IA
|
Family ID: |
25121838 |
Appl. No.: |
11/089058 |
Filed: |
March 24, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11089058 |
Mar 24, 2005 |
|
|
|
09781148 |
Feb 8, 2001 |
|
|
|
Current U.S.
Class: |
524/847 |
Current CPC
Class: |
F24B 1/1808 20130101;
F24C 3/006 20130101; C04B 28/24 20130101; C04B 2111/28 20130101;
C04B 28/24 20130101; C04B 14/46 20130101; C04B 28/24 20130101; C04B
14/42 20130101; C04B 14/38 20130101; C04B 40/0259 20130101; C04B
24/2641 20130101 |
Class at
Publication: |
524/847 |
International
Class: |
C08K 003/00 |
Claims
We claim:
1. A compression molding composition for use in compression molding
an article, said composition comprising: an inorganic fiber, a
binder, and a carrier solvent; wherein the composition comprises
less than about 25% by wt. inorganic fiber in an amount to be bound
by the inorganic binder during the compression molding to form the
article; and wherein substantially all of the inorganic fiber
comprises a fiber length of at least about 1/8 of an inch.
2. The composition of claim 1, wherein the fiber length is less
than about 2 inches.
3. The composition of claim 2, wherein the fiber length is less
than about 1 inch.
4. The composition of claim 3, wherein the fiber length is about
1/8 of an inch to 1/2 of an inch.
5. The composition of claim 1, wherein substantially all of the
inorganic fiber comprises a diameter in a range of 1 micron to 30
microns.
6. The composition of claim 5, wherein the diameter is in the range
of 4 microns to 9 microns.
7. The composition of claim 6, wherein the diameter is in the range
of 5 microns to 7 microns.
8. The composition of claim 1, wherein the inorganic fiber
comprises glass fibers, ceramic fibers, refractory fibers,
refractory ceramic fibers, mineral fibers, or mixtures thereof.
9. The composition of claim 1, wherein the inorganic fiber
comprises chopped fiber glass.
10. The composition of claim 1, wherein the binder comprises
silica, sodium, calcium, and magnesium based binders, or mixtures
thereof.
11. The composition of claim 1, further comprising a carrier
solvent.
12. The composition of claim 11, wherein the carrier solvent
comprises water.
13. The composition of claim 1, wherein the composition comprises
less than about 10% by wt. inorganic fiber.
14. The composition of claim 13, wherein the composition comprises
less than about 5% by wt. inorganic fiber.
15. The composition of claim 1, wherein the composition comprises
in the range of about 15 to 35% by wt. binder.
16. The composition of claim 15, wherein the composition comprises
in the range of about 20 to 30% by wt. binder.
17. The composition of claim 1, wherein the composition comprises
in the range of about 15 to 45% by wt. carrier solvent.
18. The composition of claim 17, wherein the composition comprises
in the range of about 20 to 40% by wt. carrier solvent.
19. The composition of claim 18, wherein the composition comprises
in the range of about 25 to 35% by wt. carrier solvent.
20. The composition of claim 1, wherein the composition comprises
in the range of about 0 to 70% by wt. additional additives.
21. The composition of claim 20, wherein the additional additives
comprise an inorganic filler in the range of 15 to 70% by weight of
the total composition.
22. The composition of claim 1, wherein the composition has a
moisture content in the range of 20 to 35% by weight of the total
composition.
23. The composition of claim 1, wherein the composition comprises
in the range of about 15 to 35% by wt. inorganic binder, in the
range of about 15 to 45% by wt. carrier solvent, and in the range
of about 0 to 70% by wt. additional solid additives.
24. A molding composition for use in forming an article, said
composition comprising: an inorganic fiber, an inorganic binder,
and a carrier solvent; wherein the composition comprises less than
about 25% by wt. inorganic fiber in an amount to be bound by the
inorganic binder during the forming of the article; wherein the
composition comprises in the range of about 15 to 35% by wt.
inorganic binder; wherein the composition comprises in the range of
about 15 to 45% by wt. carrier solvent; and wherein the composition
comprises in the range of about 0 to 70% by wt. additional solid
additives.
25. The composition of claim 24, wherein at least a portion of the
inorganic binder is suspended in at least a portion of the carrier
solvent.
26. The composition of claim 24, wherein the inorganic binder and
at least a portion of the carrier solvent form a colloidal
silica.
27. The composition of claim 24, wherein the molding composition is
a compression molding composition.
28. A molding composition for use in forming an article, said
composition comprising: an inorganic fiber and an inorganic binder,
wherein at least a portion of the inorganic binder is suspended in
a carrier solvent; wherein the composition comprises less than
about 25% by wt. inorganic fiber in an amount to be bound by the
inorganic binder during the forming of the article; wherein the
composition comprises in the range of about 15 to 35% by wt.
inorganic binder; and wherein substantially all of the inorganic
fiber comprises a fiber length of at least about 1/8 of an
inch.
29. The composition of claim 28, wherein the molding composition is
a compression molding composition.
30. The composition of claim 28, wherein the fiber length is less
than about 2 inches.
31. The composition of claim 28, further comprising in the range of
about 15 to 45% by wt. carrier solvent.
Description
RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/781,148 filed on Feb. 8, 2001 and titled
"Compression Molded Inorganic Fiber Articles, and Methods and
Compositions Used in Molding Same," the entirety of which is hereby
incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to a method of compression
molding, and to articles produced using compression molding. The
invention also relates generally to a molding composition including
inorganic fibers for use in such compression molding methods and
compression molded articles. More specifically, the invention
relates to compression molding an inorganic fiber matrix to form
articles made up of inorganic fiber.
BACKGROUND OF THE INVENTION
[0003] Vacuum formed articles made of ceramic or refractory fibers
are generally known. For example, it is known to mix chopped dry
ceramic fibers with water and various fillers to form a slurry, and
then vacuum form the slurry into various articles composed mainly
of chopped ceramic fibers. Such articles are often used in high
temperature environments, and can withstand high temperatures
without decomposition or deformation of the articles. For example,
fireplace boxes and artificial fireplace logs have been produced by
using such vacuum forming techniques.
[0004] Vacuum forming techniques of forming ceramic fiber articles
have been very useful, but it would be desirable to provide an
alternative method of forming ceramic fiber articles that does not
involve vacuum forming. Vacuum forming techniques tend to be slow,
dirty, and relatively complicated. Additionally, it would be
desirable to provide ceramic fiber articles that have increased
strength, dimensional stability, and thermal conductivity
properties as compared to those formed using vacuum forming
techniques.
SUMMARY OF THE INVENTION
[0005] The invention provides a method of forming articles made of
an inorganic fiber material using compression molding. The use of
compression molding to form inorganic fiber articles is distinctly
different from vacuum forming techniques of making such articles.
Additionally, in at least some embodiments, the use of compression
molding to form inorganic fiber articles provides for an
improvement over vacuum forming techniques, and in some
embodiments, provides for inorganic fiber articles having desirable
strength and integrity characteristics.
[0006] In one respect, the invention is directed to a method of
forming an article, the method including: providing a molding
composition comprising inorganic fiber and an inorganic binder, and
compression molding the molding composition into the article.
[0007] In another respect, the invention is directed to a method of
forming an article, the method including: providing a molding
composition comprising inorganic fibers and a binder, and
compression molding the molding composition into the article,
wherein at least 75% by weight of the molded article is inorganic
material.
[0008] In another respect, the invention is directed to a method of
forming an article, the method including: providing a molding
composition comprising inorganic fibers and a binder, and
compression molding the molding composition into the article such
that the binder cures, wherein the cured binder is capable of
withstanding temperatures of at least 600.degree. F. without
significant degradation or deterioration due to heat.
[0009] In another respect, the invention is directed to a method of
forming an article, the method including: providing a molding
composition comprising inorganic fibers and a binder, and
compression molding the molding composition into the article,
wherein the article is capable of withstanding temperatures of at
least 600.degree. F. without significant degradation or
deterioration due to heat.
[0010] In another respect, the invention is directed to articles
made by the use of such methods.
[0011] In another respect, the invention is directed to a molding
composition for use in compression molding an article.
[0012] In some preferred embodiments, the compression molded
inorganic fiber articles are intended for use in high temperature
environments. For example, some embodiments are contemplated for
use as a component of: a fireplace assembly, a grill assembly, a
campfire assembly, a burner assembly, or the like. Examples of such
articles can include a fireplace box, a surround, a combustion
chamber, a fireplace door, a log or log set, a burner, and a
refractory member. However, as will be understood by those of skill
in the art and others, while certain specific embodiments of the
invention will be illustrated in describing preferred embodiments
of the invention, the invention is not to be limited to use in such
embodiments. The invention is contemplated for use in a broad
variety of applications and industries, and to create inorganic
fiber articles made of any desired shape or size. These and other
modifications of the invention will be understood by those skilled
in the art in view of the following description of the invention,
with reference to specific embodiments thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Referring to the figures, wherein like numerals represent
like parts throughout the several views:
[0014] FIG. 1 is a front perspective view of a compression-molded
combustion chamber in accordance with one embodiment of the
invention;
[0015] FIG. 1B is a back perspective view of the compression molded
combustion chamber of FIG. 1;
[0016] FIG. 2 is a front view of the compression molded combustion
chamber of FIG. 1;
[0017] FIG. 3 is a top view of the compression molded combustion
chamber of FIG. 1;
[0018] FIG. 4 is a bottom view of the compression molded combustion
chamber of FIG. 1;
[0019] FIG. 5 is a back view of the compression molded combustion
chamber of FIG. 1;
[0020] FIG. 6 is a side view of the compression molded combustion
chamber of FIG. 1;
[0021] FIG. 7 is cross-sectional view of the compression molded
combustion chamber of FIG. 1 taken along line 7-7 of FIG. 2;
[0022] FIG. 8 is a cross-sectional view of the compression molded
combustion chamber of FIG. 1 taken along line 8-8 of FIG. 2;
[0023] FIG. 9 is a cross-sectional view of the compression molded
combustion chamber of FIG. 1 taken along line 9-9 of FIG. 2;
[0024] FIG. 10 is a cross-sectional view of the compression mold
used to mold the combustion chamber of FIG. 1 showing the mold in
an open position with unmolded inorganic fiber composition in the
bottom portion of the mold;
[0025] FIG. 11 is a cross-sectional view of the compression mold of
FIG. 10 showing the mold in a closed position and molding the
inorganic fiber composition;
[0026] FIG. 12 a cross-sectional view of the compression mold of
FIG. 10 showing the mold in an open position and the compression
molded combustion chamber in accordance with one embodiment of the
invention.
[0027] FIG. 13 is a schematic top view of a monolithic panel for a
gas burner according to one embodiment of the invention;
[0028] FIG. 14 is a schematic cross-sectional view of the
monolithic panel of FIG. 13, taken along line 14-14 of FIG. 13;
[0029] FIG. 15 is a schematic cross-sectional view of the
monolithic panel of FIG. 13, taken along line 15-15 of FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] The invention relates to the use of compression molding
techniques to mold a matrix including inorganic fibers into useful
articles. In some embodiments, methods of the invention generally
include providing a molding composition including inorganic fibers
and a binder, and compression molding the molding composition into
the article.
[0031] Compression Molding
[0032] The first step involved in one embodiment of such a molding
method entails providing the molding composition. The molding
composition generally includes inorganic fibers, binder, carrier
solvent, and optional additives. A more detailed discussion of some
embodiments of the molding composition will be provided below.
[0033] The next step entails compression molding the molding
composition. Compression molding as used herein generally involves
the use of a heated mold and compressive pressure produced by the
mold to form the moldable composition into a desired shape. Many
compression molding techniques may be used. For example, in some
embodiments the mold comprises a plurality of matched dies, and in
some embodiments, a pair of dies, for example male and female dies,
that mate with each other to form a mold cavity or mold cavities.
In some embodiments, the dies are attached to equipment that is
designed to bring the dies together with enough compressive
pressure to perform the molding. It is contemplated that in other
embodiments, the weight of the dies can create enough compressive
pressure to perform the molding. The dies are typically preheated
to a molding temperature, and a measured quantity of moldable
composition including inorganic fiber is placed in the heated mold.
In some embodiments, the moldable composition is placed in the
heated mold when the mold is in the open position. The mold is then
closed and the moldable composition, through pressure applied from
the closing of the mold, fills the mold cavity. Continued heating
at least partially cures the moldable composition within a
relatively short period of time, in some embodiments within a
matter of minutes, such that the molded article retains its shape.
Pressure is then released, the dies are separated, and the molded
article is removed from the mold.
[0034] It should also be understood that in some embodiments of
compression molding, the moldable composition is forced into the
heated mold through one or more injection ports using appropriate
injection techniques when the mold is in the closed position. The
moldable composition, through pressure from the injection process,
and compression from the closed mold dies, fills the mold cavity,
and is formed into the desired shape. Therefore, it will be
understood that as used herein, the terms "compression molding" is
intended to include embodiments using all types of known
compression molding, including such injection techniques.
[0035] One particular embodiment of compression molding the
moldable composition including inorganic fiber will now be
described, with reference to FIGS. 10-12.
[0036] Referring to FIG. 10, a cross section of a compression mold
120 in an open position is shown, including a top die 122 and a
bottom die 124 which together define a mold cavity 126 in the
desired shape of the article to be molded. In the embodiment shown,
the article to be molded is a monolithic combustion chamber for use
in a fireplace assembly, for example a combustion chamber of a gas
fireplace assembly. The mold cavity 126 includes an upper surface
135 and a lower surface 136. Typically, the mold surfaces 135 and
136 are hardened and highly polished. The mold may also include
ejector pins (not shown), or other such structures as generally
known in the art, to aid in the removal of the article when the
molding process is complete. The dies are mounted on platens 140
and 142 of a press 144, for example a vertical hydraulic press. The
press 144 is operated to open and close the mold 120, and typically
is able to create the necessary compression pressure for
molding.
[0037] The dies 122 and 124 are preheated to a predetermined
molding temperature. In some embodiments, the molding temperature
is over 400.degree. F., preferably in the range of 425.degree. F.
to 475.degree. F., or in the range of 440.degree. F. to 460.degree.
F., and more preferably about 450.degree. F. In some embodiments,
the dies 122 and 124 are preheated using heated platens 140 and
142, and heat is transferred from the platens 140 and 142 to the
dies 122 and 124.
[0038] The molding composition including inorganic fibers 150 is
then introduced into the lower die 122, and the press 144 is
operated to close the mold 120. (FIG. 11). As the mold 120 is
closed, an appropriate amount of compression molding pressure is
applied to achieve the desired molding. As will be understood by
those of skill in the art and others, the necessary amount of
molding pressure is dependent upon many variables, for example the
size and complexity of the article being molded, the properties of
the particular molding composition used, and other such parameters.
In some embodiments, a compression pressure of up to 50 tons is
applied. In other embodiments, a compression pressure in the range
1 to 20 tons, or in the range of 3 to 10 tons is applied.
[0039] The moldable composition 150, through pressure applied from
the closing of the mold 120, fills and is formed into the shape of
the mold cavity. Continued heating of the composition in the mold
at least partially cures the moldable composition within a
relatively short period of time, in some embodiments within a
matter of minutes, such that the molded article retains its shape.
The amount of time necessary can vary, depending upon the size and
shape of the part, the properties of the particular molding
composition used, and other such parameters.
[0040] Referring now to FIG. 12, the press is operated to separate
the dies 122 and 124, and the molded article 151 is removed from
the mold 120. After the molding process is complete, and the molded
article is removed from the mold, it can be further dried by either
air drying, or in some cases, by oven drying or firing. In some
embodiments, however, the article can be dried by being held in the
heated mold for a longer period of time to achieve the desired
drying.
[0041] For larger articles, for example, a molded combustion
chamber, additional drying can be achieved by oven drying after
removal from the mold at a temperature in the range of 350.degree.
F. and 1800.degree. F., more preferably in the range of 650.degree.
F. to 750.degree. F. for a sufficient amount of time to drive off
any of the remaining excess carrier solvent, for example water,
from the mold composition. The dry time depends greatly upon the
method of drying used, and the article being formed.
[0042] After the drying, the article can be trimmed or machined to
a final desirable shape, if needed, and colored as desired.
[0043] Molding Composition Formulation
[0044] The molding composition generally includes inorganic fibers,
binder, carrier solvent, and optional additional additives.
[0045] The inorganic fiber is generally described as fibers made of
one or more inorganic materials. Some examples of inorganic fibers
include glass fibers, ceramic fibers, refractory fibers, refractory
ceramic fibers (RCF), mineral fibers, or other like inorganic
fibers, or mixtures thereof. Such fibers can include, for example,
staple fiber, spun fiber, continuous fiber, bulk fiber, filament
fiber or wool fibers or the like, or mixtures thereof.
Additionally, the fibers can be in a broad variety of forms, for
example, in a crystalline or polycrystalline form, or the like, or
mixtures thereof. Refractory ceramic fibers (RCFs), along with
fibrous glass and mineral wool, are often times grouped as man-made
materials generally referred to as synthetic vitreous fibers (SVF).
All these products are made from molten masses of raw materials,
under controlled conditions.
[0046] In some embodiments the fibers are selected from chopped
fiber glass, alumina silicate RCF, or mixtures thereof. In some
embodiments, especially those for use in high temperature
environments, it is preferable to use fibers that can withstand
high temperatures. For example, in such embodiments, it is
preferable to use fibers that can withstand temperatures of at
least 800.degree. F., more preferably at least 1000.degree. F.,
more preferably at least 1200.degree. F., and more preferably
1300.degree. F., without significant degradation or deterioration
due to the heat.
[0047] The size of the inorganic fibers can vary greatly, depending
upon many variables, for example the particular article being
molded, or the desired properties or characteristics of the molding
composition or the finished article. In some embodiments, the
fibers range in length from less than {fraction (1/16)} of an inch
to two inches, preferably from {fraction (1/16)} of an inch to 1
inch, and more preferably from 1/8 of an inch to 1/2 of an inch. In
some embodiments, the fibers have a diameter in the range of 1
micron to 30 microns, preferably in the range of 4 microns to 9
microns, and more preferably in the range of 5 microns to 7
microns.
[0048] The fibers can make up a major component of the composition,
for example in some envisioned embodiments, up to 80% or more of
the composition. However, in some embodiments, a significant amount
of fillers, for example inorganic fillers, can be used, thereby
reducing the necessary concentration of inorganic fiber.
[0049] The binder used acts to bind the components of moldable
composition together when cured during the molding process. The
binder includes inorganic or organic binders generally known, or
mixtures thereof. Examples of binders include silica, sodium,
calcium, and magnesium based binders, and the like, or mixtures
thereof. Other examples include polymeric materials, petroleum
distillate, polyethylene oxide, and the like, or mixtures thereof.
In some embodiments, the binder can be hydrous, anhydrous,
crystalline, or amorphous. In some embodiments, the binder within
the molding composition in the form of a dispersion, emulsion,
slurry or solution with the carrier medium.
[0050] In some embodiments, especially those for use in high
temperature environments, it is preferable to use binders that can
withstand high temperatures. For example, in such embodiments, it
is preferable to use binders that can withstand temperatures of at
least 600.degree. F., or at least 800.degree. F., or least
1000.degree. F., or at least 1200.degree. F., and more preferably
at least 1300.degree. F., without significant degradation or
deterioration due to the heat. The preferred binders include
amorphous silica.
[0051] The carrier solvent typically acts to create a dispersion,
emulsion, slurry or solution with the rest of the components.
Preferably, the moldable composition is in the form of a slurry. In
most embodiments, the carrier solvent is burned off or leaves due
to the heat during the molding process, and little or none remains
in the finished molded article. The preferred carrier solvent for
most embodiments is water. In at least some embodiments, the
moldable composition preferably includes water as the primary
carrier solvent. The composition preferably has a moisture content
in the range of 20 to 35%, more preferably 23 to 30%, and most
preferably 25 to 27% by weight of the total composition.
[0052] Additional additives can optionally be included within the
molding composition to provide the molding composition or the final
molded article with desirable properties. For example, additives
can be included to enhance the emulsion or dispersion of the
components of the composition, to enhance the moldability of the
composition or to enhance the appearance or physical properties of
the molded article. Some examples of additives include inorganic or
organic fillers, surfactants, diluents, thickeners, solvents, dyes
or colorants, or other appearance enhancing materials, and the
like, or mixtures thereof.
[0053] Fillers can be used, for example, to increase the volume of
the composition and reduce the necessary amount of inorganic fiber.
Additionally, some fillers can be added to impart desired
properties to the final molded article. Examples of fillers include
inorganic or organic fillers that are compatible with the other
components in the composition. Preferred fillers include inorganic
fillers, for example silica compounds, such as alumina silicate,
crystalline silica, and the like. Another example of an inorganic
filler includes ceramic micro spheres, and the like.
[0054] In some embodiments, an example of a preferred emulsion or
dispersion agent is petroleum distillate, hydrotreated light. This
material can also act as a carrier in the formulation. Nonylphenol
polyethylene oxide is another example of a dispersing or
emulsifying agent that can also act as a surfactant.
[0055] In some embodiments, an organic polymer, such as an acrylic
polymer, is added to the composition to act as a dispersing agent,
and also to act as a molding thickener to help the composition hold
shape when it is being molded. Typically, this type of material is
burned off during the molding process. The organic polymer can be
present in the composition in the range of about 0.1 to about 5%,
more preferably in the range of 0.1 to 1%, and more preferably in
the range of 0.1 to 0.5%, by weight of the total composition. It is
contemplated that these, and many other additives can be used in
compositions embodying the invention.
[0056] Representative constituent concentrations for base
components of some examples of moldable compositions embodying the
invention can be found in Table 1, wherein the values are given in
wt. % of the ingredients in reference to the total composition
weight.
1TABLE 1 Exemplary wt. % Preferred wt. % More Preferred Component
Range Range wt. % Range Inorganic Fiber up to 80%, but 25% or less
10% or less preferably 75% or less Binder 10 to 40% 15 to 35% 20 to
30% Carrier Solvent 15 to 45% 20 to 40% 25 to 35% Additives 0 to
70% 25 to 80% 33 to 54%
[0057] Some embodiments of moldable compositions comprise the
constituent concentrations for base components as found in Table 2,
wherein the values are given in wt. % of the ingredients in
reference to the total composition weight.
2TABLE 2 Example wt. % Preferred wt. % More Preferred Component
Range Range wt. % Range Inorganic Fiber 25% or less 10% or less 5%
or less Inorganic Binder 10 to 40% 15 to 35% 20 to 30% Water 15 to
45% 20 to 40% 25 to 35% Inorganic Filler 15 to 70% 20 to 60% 30 to
54% Other additives 0 to 10% 0 to 5% 0.1 to 2%
[0058] In some embodiments, the molding composition is made by
mixing the inorganic fibers and any filler with a binder solution
that is in aqueous form and includes any additional additives.
After the combination of fibers, filler and binder solution are
mixed together, they are agitated so that the fibers completely
adsorb the binder solution. After the mixing and agitation occurs,
a slurry or paste is formed that is of a consistency that permits
the mixture to be used to fill the compression mold, and is ready
to be compression molded.
[0059] One specific example of a molding composition comprises the
constituent concentrations for base components as found in Table 3,
wherein the values are given in wt. % of the ingredients in
reference to the total composition weight.
3 TABLE 3 Component Weight Percent Chopped Fiber 3.3% Glass
Colloidal Silica (in 60% a 50% water solution) Alumina Silicate 34%
Acrylic Polymer 0.2% Ceramic Micro 2.5% spheres
[0060] Another specific example of a molding composition comprises
the constituent concentrations for base components as found in
Table 4, wherein the values are given in wt. % of the ingredients
in reference to the total composition weight.
4 TABLE 4 Component Weight Percent Chopped Fiber 3.66% Glass
Colloidal Silica (in 19% a 50% water solution) Alumina Silicate
48.35% Acrylic Polymer 0.22% Ceramic Micro 2.77% spheres Water
26%
[0061] One preferred moldable slurry of ceramic fibers is a product
named THERMOSEAL.RTM. Moldable P244, which is commercially
available from Mid-Mountain Materials Incorporated of Seattle,
Wash. Another preferred moldable slurry of ceramic fibers is a
product named THERMOSEAL.RTM. Moldable P254, which is commercially
available from Mid-Mountain Materials Incorporated of Seattle,
Wash.
[0062] In some embodiments, the molding composition or the finished
article, are made up of primarily inorganic materials. For example,
in some embodiments, the molding composition or the finished
article, include at least 75% by weight inorganic material, or in
other embodiments, at least 90% by weight inorganic material, and
in still other embodiments, at least 95% by weight inorganic
material, and sometimes at least 99% by weight inorganic material.
It is also contemplated that in some embodiments, the molding
composition, prior to molding, includes a mixture of inorganic and
organic material, but that a significant portion of the organic
material will be burned off, or leave during the molding process,
leaving the final compression molded article to be made up of
primarily inorganic materials. In some embodiments, especially
those for use in high temperature environments, it is preferable
that the final compression molded article comprises materials that
can withstand high temperatures. For example, in such embodiments,
it is preferable to use fibers, binders, or any other optional
ingredients, such as fillers, that when molded into the final
article can withstand temperatures of at least 600.degree. F., or
at least 800.degree. F., or least 1000.degree. F., or at least
1200.degree. F., and more preferably at least 1300.degree. F.,
without significant degradation or deterioration due to the
heat.
[0063] Combustion Chamber Enclosure
[0064] FIGS. 1-9 show one embodiment of a compression molded
article that was molded in accordance with the invention.
Specifically, a compression molded monolithic combustion chamber
enclosure 251 for use in a fireplace, for example a gas fireplace,
is shown. The combustion chamber enclosure 251 defines an outer
surface 254 and inner surface 256. The combustion chamber enclosure
includes a bottom panel 258, side panels 260 and 262, a top panel
264, and a back panel 265. Optionally, the combustion chamber
enclosure 251 can define one or more apertures that are formed
through the one or more of the panels during the compression
molding process. Alternatively, the one or more apertures can be
formed through one or more of the panels after the molding
process.
[0065] In one embodiment, the top panel 264 defines an aperture
268, for example, for venting combustion products, the back panel
265 defines an aperture 270, for example, for supplying air or gas
to the combustion chamber 251, and the bottom panel 258 defines an
aperture 272, for example, for supplying air or gas to the
combustion chamber, as shown in FIGS. 1-9. In this embodiment, the
aperture 268 and the aperture 272 were formed in the combustion
chamber in post molding operations, while the aperture 270 was
formed in the combustion chamber during the molding process. The
combustion chamber enclosure 251 includes raised portions 274 on
the outer surface 254, for example, to provide a space between the
combustion chamber enclosure 251 and a structure into which the
combustion chamber enclosure is eventually inserted.
[0066] The combustion chamber enclosure 251 can also include a
design, such as a masonry design 276 formed into at least a portion
of the inner surface 256. For example, FIG. 2 shows a simulated
brick design 276 on the back panel 265 and side panels 260 and 262
of the combustion chamber enclosure. The masonry design can also be
formed into the bottom panel 258 and top panel 264. Other masonry
designs include, but are not limited to, stone or concrete.
Alternatively, the combustion chamber enclosure can be formed
without a masonry design, or with other designs.
[0067] Burner Panel
[0068] Another particular embodiment of an article that can be
molded in accordance with the invention is shown in FIGS. 13-15.
Specifically, a compression molded monolithic gas burner panel 351
is shown. The monolithic gas burner panel 351 defines a top surface
354 and a bottom surface 356. The top surface 354 defines a raised
upper portion 360 and a lower portion 362. The raised upper portion
360 is defined by one or more elevated areas 374 and 376, shown for
example, in FIGS. 14 and 15. The elevated area or areas 374 and 376
can be formed into any number of generic shapes including, but not
limited to, rounded, trapezoid, crescent, or any other desired
shape. For example, FIGS. 13-15 show elevated areas of a general
trapezoid shape having areas of irregular shape. Optionally, the
elevated area is formed into at least one preformed log that
includes contours and detail in the top surface of the burner panel
that simulates a log.
[0069] The bottom surface 356 defines at least one cavity 364 below
at least one of the elevated areas 374 and 376. A portion of at
least one cavities 364 extend above at least a portion of the top
surface 354, as shown in FIGS. 14 and 15. In some embodiments, the
bottom surface 356 defines a cavity 364 under each of the elevated
areas 366. In other embodiments, there can be elevated areas that
do not include a cavity there under that extends above the top
surface 354. The burner panel 351 can be formed as a bottom panel
of a combustion chamber enclosure, such as the combustion chamber
enclosure shown in FIGS. 1-9.
[0070] The burner panel 351 can optionally define one or more
apertures, for example burner apertures that are formed into the
burner panel 351 during the compression molding process.
Alternatively, the one or more apertures can be formed into the
burner panel after the molding process.
[0071] The burner panel 351 can also include a masonry design 370
formed, for example, into a portion of the lower portion of the top
surface. For example, FIG. 13 shows a simulated brick design on
part of the lower portion. Other masonry designs include, but are
not limited to, stone or concrete. Alternatively, the burner panel
can be formed without a masonry design, or with another design.
[0072] Although a number of specific embodiments of the invention
for use in fireplace or burner applications have been discussed, it
will be understood by those of skill in the art and others, the
invention is contemplated for use in and to form a broad variety of
articles made of any desired shape or size and for use in a broad
variety of applications or industries. Some examples of additional
structure contemplated in the fireplace or burner industry include
compression molded combustion chamber enclosures or burners for
direct vent, universal vent, B-vent, dual direct vent, multisided
unit having two or three glass panels as combustion chamber side
panels, or in any fireplace or combustion unit, stove, or insert
are contemplated. Some specific examples of other fiber structures
that can be molded in accordance with the compression molding
methods of this invention are disclosed in U.S. Pat. Nos. 5,941,237
and 5,996,575, which are herein incorporated by reference.
[0073] The above specification provides a basis for understanding
the broad meets and bounds of the invention. Variations within the
concepts of the invention are apparent to those skilled in the
art.
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