U.S. patent number 3,613,658 [Application Number 04/383,785] was granted by the patent office on 1971-10-19 for heating composition.
This patent grant is currently assigned to Texaco Inc.. Invention is credited to Edwin C. Knowles, Frederic C. McCoy.
United States Patent |
3,613,658 |
Knowles , et al. |
October 19, 1971 |
**Please see images for:
( Certificate of Correction ) ** |
HEATING COMPOSITION
Abstract
A heating composition consisting essentially of from 75 to 99.8
percent by weight of a wax component containing a microfibrous
material component in contact with the wax in an amount sufficient
to increase the burning rate of the composition. The microfibrous
material component consists essentially of from 0.2 to 25 percent
by weight of an inorganic substantially noncombustible material.
The heating composition can be used as a fire starter and in a
container as a solid fuel heater.
Inventors: |
Knowles; Edwin C.
(Poughkeepsie, NY), McCoy; Frederic C. (Beacon, NY) |
Assignee: |
Texaco Inc. (New York,
NY)
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Family
ID: |
23514716 |
Appl.
No.: |
04/383,785 |
Filed: |
July 20, 1964 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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288866 |
Jun 19, 1963 |
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229205 |
Oct 8, 1962 |
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Current U.S.
Class: |
44/275; 44/519;
12/59.5; 44/540; 431/291; 44/541 |
Current CPC
Class: |
A01G
13/06 (20130101) |
Current International
Class: |
A01G
13/06 (20060101); A01g 013/06 () |
Field of
Search: |
;44/41,7.5,634,38,39,40
;126/59.5 ;67/DIG.22 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Myhre; Charles J.
Parent Case Text
The application is a continuation-in-part application of copending
application Ser. No. 288,866, filed June 19, 1963 which in turn is
a continuation-in-part application of copending application Ser.
No. 229,205, filed Oct. 8, 1962, both now abandoned.
Claims
Obviously, many modifications and variations of the invention, as
hereinbefore set forth, may be made without departing from the
spirit and scope thereof, and therefore only such limitations
should be imposed as are indicated in the appended claims. only
such limitations should be imposed as are indicated in the appended
claims. We claim:
1. A heating composition consisting essentially of from 75 to 99.8
percent by weight of a wax component containing a microfibrous
material component in contact with said wax in an amount sufficient
to increase the burning rate of said composition, said microfibrous
material component consisting essentially of from 0.2 to 25 percent
by weight of an inorganic substantially noncombustible material and
mixtures thereof.
2. A composition as claimed in claim 1 wherein the microfibrous
material has an average fiber diameter between 0.01 and 25
microns.
3. A composition as claimed in claim 1 wherein said wax component
is a refined petroleum wax having a melting point temperature range
of from about 100.degree. to 200.degree. F.
4. A composition as claimed in claim 1 wherein said microfibrous
material component comprises from 0.5 to 15 percent by weight of
glass microfibers having an average fiber diameter between 0.01 and
4 microns.
5. A composition as claimed in claim 1 wherein said microfibrous
material component comprises from 5 to 25 percent by weight of
asbestos microfibers having an average fiber diameter between 0.01
and 4 microns.
6. A composition as claimed in claim 1 additionally containing an
ignitable wick disposed in said wax component having an end portion
accessible for ignition.
7. An article of manufacture comprising a combustible container, a
plurality of charcoal briquettes substantially filling said
container, and a heating composition disposed in said container in
contact with a plurality of said briquettes, said heating
composition consisting essentially of from 75 to 99.8 percent by
weight of paraffin wax containing a microfibrous material
consisting essentially of from 0.2 to 25 percent weight of
inorganic substantially noncombustible microfibers and mixtures
thereof in an amount sufficient to increase the burning rate of
said paraffin wax.
8. An article of manufacture as claimed in claim 7 and comprising
an ignitable wick disposed in said container having one end thereof
accessible for ignition.
9. An article of manufacture comprising a fire-resistant container
having an open end, a heating composition substantially filling
said container, said heating composition consisting essentially of
from 75 to 99.8 percent by weight of a wax component and from 0.2
to 25 percent by weight of a microfibrous material component in
contact with the wax component, said microfibrous material
component being present in the composition in an amount sufficient
to increase the burning rate of said wax, said microfibrous
material consisting essentially of from 0.2 to 25 percent by weight
of an inorganic substantially noncombustible material and mixtures
thereof.
10. An article of manufacture as claimed in claim 9 wherein the wax
component in said composition is from about 75 to about 99.5
percent by weight and the microfibrous material component in said
composition is from about 0.5 to about 25 percent by weight.
11. An article of manufacture as claimed in claim 9 wherein the
microfibrous material component is dispersed in the upper 25
percent of the wax component adjacent to the open end of the
container.
12. An article of manufacture as claimed in claim 9 wherein the
microfibrous material component is partially embedded in that
portion of the wax component adjacent to the open end of the
container.
13. An article of manufacture as claimed in claim 9 wherein the
microfibrous material component is dispersed throughout the wax
component.
14. An article of manufacture as claimed in claim 9 wherein the
microfibrous material component on ignition and melting of the
upper portion of the wax component becomes partially immersed in
the burning wax.
15. An article of manufacture as claimed in claim 9 wherein said
microfibrous material component comprises glass microfibers having
an average fiber diameter in the range of from about 0.01 to about
0.5 micron.
16. An article of manufacture as claimed in claim 9 wherein said
microfibrous material component comprises asbestos fibers having an
average fiber diameter between 0.01 and 4 microns.
17. An article of manufacture as claimed in claim 9 wherein said
microfibrous material component comprises a mat of glass
fibers.
18. An article of manufacture comprising a cylindrical
fire-resistant paper container having an open end and a closed end,
a heating composition substantially filling said container
consisting essentially of from 75 to 99.8 percent by weight of a
petroleum wax component and from 0.2 to 25 percent by weight of a
microfibrous material in contact with said petroleum wax, said
microfibrous material consisting essentially of from 0.2 to 25
percent by weight of an inorganic noncombustible material and
mixtures thereof, and wherein the microfibrous material is present
in said container in an amount sufficient to increase the burning
rate of said petroleum wax.
19. An article of manufacture as claimed in claim 18 wherein said
container comprises a paper container externally covered with an
aluminum foil having a thickness in the range of from 0.0002 to
0.005 inch.
20. An article of manufacture as claimed in claim 18 wherein said
container is a seamless convolute kraft paper container externally
coated with sodium silicate.
21. An article of manufacture comprising a seamless cylindrical
convolute cardboard container externally covered with an aluminum
foil having a thickness between 0.00035 and 0.0015 inch, said
container having an open end and a closed end, said container being
substantially filled with a composition comprising 85 to 99.5
percent by weight of petroleum wax and 0.5 to 15 percent by weight
of glass microfibers having an average fiber diameter in the range
of from about 0.01 to about 0.5 microns, said glass microfibers
being in the form of a mat and being in contact with that portion
of the wax adjacent to the said open end of the container.
22. An article of manufacture as claimed in claim 21 wherein a
portion of the glass microfibers is embedded in the wax.
23. A composition as claimed in claim 1 wherein said wax component
is stearic acid.
24. An article of manufacture as claimed in claim 18 wherein said
container comprises a paper container externally coated with a
fire-resistant paint.
25. An article of manufacture as claimed in claim 18 wherein said
container comprises a paper container externally coated with a
fire-resistant coating selected from the group consisting of sodium
silicate or ammonium dihydrogen phosphate.
26. A solid-fueled heater which comprises a container consisting of
a lower end and a body of combustible material, the outside of said
material covered with a flameproof and water-resistant substance; a
wax having a melting point above about 140.degree. F. which
substantially fills said container; and a wax-impregnated,
heat-insulating, noncombustible cap which is in said container
contiguous with said wax and conforms in shape to said lower end of
said container.
27. A solid-fueled heater in accordance with claim 26 wherein said
container is cylindrical.
28. A solid-fueled heater in accordance with claim 26 wherein said
container is rectangular.
29. A solid-fueled heater in accordance with claim 26 wherein said
wax has a melting point within the range of 150.degree. to
170.degree. F.
30. A heater which comprises: a container consisting of a
cylindrical can consisting of a metal lower end and a fiber body,
the outside of said fiber body covered with a flameproof and
water-resistant substance; a wax having a melting point above about
140.degree. F. which substantially fills said container; and a
wax-impregnated, heat-insulating, noncombustible cap which is in
said container contiguous with said wax.
31. A heater in accordance with claim 30 wherein said cap is made
of rock wool.
32. A heater in accordance with claim 30 wherein said cap is made
of asbestos.
33. A heater in accordance with claim 30 wherein said wax has a
melting point within the range of 150.degree. to 170.degree. F.
Description
The present invention relates to novel heating compositions,
methods of making the novel compositions, and methods of using such
compositions. More particularly, the present invention in one
aspect is directed to novel heating compositions for lighting
campfires, signal fires, cooking and heating fires in stoves and
fireplaces, both indoors and outdoors, and also for igniting trash
or rubbish piles and for the protection of growing crops and plants
during intermittent and/or extended periods of cold weather.
Heretofore, fires have been started or lit in various ways, for
example, by first lighting kindling wood or other readily
combustible materials such as paper, rags or relatively low boiling
hydrocarbonaceous compositions added to the fire bed which contains
a more difficult combustible material that will be the ultimate
source of heat or light, such as coal, or logs or mixtures thereof.
Such known methods possess inherent disadvantages that tend to make
them objectionable for various reasons. For example, the use of
paper alone or in combination with kindling wood to start a fire
suffers from the disadvantage that the paper after being lighted
can be relatively easily extinguished by the elements such as the
wind or rain or combinations thereof before the more difficult
combustible material is ignited and burning. Moreover, in modern
times, particularly in the cities and suburbs, ready accessibility
to a source of kindling wood is not as easy as it was heretofore.
In addition, there is the inconvenience, accompanied by a certain
amount of hazard, in cutting up kindling wood to suitable
sizes.
The application of readily combustible liquids such as kerosene or
aromatic distillates, sometimes in the form of aerosol gels or
foams, as a means of improving the ignitibility of firewood is also
commonly practiced. Regardless of the care exercised in using this
type of igniter a definite hazard exists. Furthermore, the storage
of such liquids, gels, or foams around the home involves a definite
risk.
Another fire-starting device now on the market comprises a package
containing a number of cylinders of wax surrounded on the sides by
cardboard covers. The cardboard is lighted and the cylinder placed
in a shallow pound pan containing a round asbestos wick. THe wax
melts, flows into the pan and is taken up and burned on the wick.
This device works satisfactorily provided it is not tipped during
operation, in which case the molten wax can spill. FUrthermore, it
depends for its operation on the pan and wick, which must be
recovered from the fire, cooled and retained for reuse. If the pan
or wick are misplaced or lost, the remaining wax cylinders are
virtually useless.
Many methods have been proposed to provide protection to growing
crops, and/or plants against cold weather damage. These known
methods generally provided for the burning of a liquid fuel such as
diesel or fuel oil, or a gaseous fuel such as natural gas or
liquified petroleum gas (LPG) in the growing area or orchard during
periods of actual or anticipated cold weather. Distribution of the
heat produced by the burning fuel throughout the growing area
frequently was accomplished by machine-driven blowers or fans or by
a pipeline distribution system in contact with or buried just below
the surface of the earth and provided with suitable risers above
ground to heat the area surrounding the crop or orchard.
Such liquid fuel systems are objectionable because of the fire
danger of spilled fuel. Another disadvantage is that the spilled
liquid fuel is harmful to the tree root system. Underground and
surface pipeline distribution systems are not satisfactory because
mechanical and cultivating equipment cannot be easily moved
throughout a growing area having a pipeline system. Moreover, such
systems are costly to install and maintain. Another known method of
providing heat to the growing area, especially in orchards
comprises individual stack-type liquid fuel burners. This method
avoids the objections of the pipeline heat system but it too is not
completely satisfactory. Such fuel burners do not provide a uniform
amount of heat to the growing area, particularly in an orchard
wherein the lower portion of the tree is likely to receive too much
heat therefrom while too little heat is provided for the upper
portion of the tree.
Smudge pots have also been used but they are not satisfactory
because of the large number of units required for a given area, the
large fuel consumption thereof, and the relatively small
temperature increase produced thereby. In addition, these devices
are not effective except at relatively low heights, thus severely
limiting their use in orchards.
It has been found that the above disadvantages of the present
methods of starting fires and protecting crops and plants from cold
weather damage can be overcome or materially decreased by the use
of the novel heating compositions of the present invention. The
heating composition of the present invention broadly is a wax
composition of any convenient size or shape having a minor amount
of inorganic substantially noncombustible microfibers or organic
nonfusible microfibers or a mixture thereof in contact therein.
More specifically, the present invention is directed to a heating
composition comprising a wax component and either an inorganic
substantially noncombustible microfibrous material component or an
organic nonfusible microfibrous material component of mixtures
thereof, the microfibrous material being in contact with the wax
and being present in an amount sufficient to increase the burning
rate of the wax component. The term "microfibrous material" as used
in the specification and claims refers to a fibrous material having
an average particle diameter not above about 100 microns.
The term "contact" in the specification and claims means that the
microfibrous material is wholly or partially embedded in the wax,
either by being dispersed throughout the wax or concentrated in the
top layer thereof; also adjacent to but separated from the wax by a
thin layer of a readily combustible substance such as paper or the
like which when ignited permits the microfibrous material to come
in contact with the burning portion of the wax.
The heating composition of the present invention comprises a wax
component in an amount of from about 75 to about 99.8 percent and
the microfibrous material component in an amount of from about 0.2
to about 25 percent by weight, based on the weight of the
composition.
In the embodiment of the present invention to protect crops and
plants against cold weather, the composition of wax and
microfibrous material is provided with a fire-resistant outer
covering or envelope having certain characteristics hereinafter
more fully described.
The advantages of the heating composition of the present invention
will become apparent in the light of the accompanying detailed
disclosure.
It is to be noted that the principal points of superiority of the
compositions of the present invention over current practices are:
(a) compactness and convenience-- the wax-microfiber compositions
provide a large amount of heat energy in a readily storable, easily
transportable form, (b) safety-- these compositions are
nonexplosive, nonvolatile, leakproof and cannot be accidentally
ignited, (c) waterproofness-- these compositions can be soaked or
immersed in water and still burn readily after shaking or blotting
off the adhering moisture; (d) these compositions are
self-contained and do not require any supplementary pans or wicks,
(e) the wax-fiber blend can be readily cast or molded into desired
shape of whatever size is required; and (f) these compositions
avoid the potential harm to plant root systems associated with
liquid fuels.
One of the novel features of the heating composition of the present
invention is its ability to spread the flame from the point of
ignition over the entire exposed surface of the composition. This
novel feature is attributable to the microfibrous material
component in cooperation with the wax component. This novel
spreading power produces an increased amount of light and heat in
comparison with wax of similar size and shape without the
microfibrous material component.
When used as a fire igniter, the ability of the composition to
spread the flame from the point or place of ignition over the
entire exposed surface of the composition causes the more difficult
combustible materials disposed in the fire bed in and about the
composition of the present invention to be ignited much more
rapidly and begin to burn sooner. Thus, the resulting ignited, less
readily combustible materials are not as likely to become
extinguished by external forces such as wind and/or rain.
Consequently, the ignited fire bed is more likely to continue
burning.
Another function of the microfibrous component in this embodiment
is to provide a support for the wax component thereby avoiding
excessive runoff of molten wax when the fire igniter is fully
ignited. This makes the use of a supporting pan unnecessary
although a pan may be use, if desired, to retain the relatively
small amount of molten wax which usually collects at the base of
the lighter.
When used to protect growing crops and plants against cold weather
damage, this spreading ability also provides a ready means of
igniting the top surface of the wax in the container and release of
a relatively large amount of heat therefrom in a short time.
When used to protect growing crops and/or plants against cold
weather damage, the heating composition is provided with an outer
container or envelope having a relatively slower burning rate than
the burning rate of the composition (a) to prevent the liquid wax
formed during the burning period from flowing down the sides of the
shaped composition and away from the composition; and, (b) to
permit substantially unrestricted access of air to the burning
surface throughout the burning period thus helping to provide a
relatively uniform rate of burning for the composition.
The present invention is illustrated by reference to the drawings
in which:
FIG. 1 is an isometric view of an embodiment of a containered
composition of the present invention, with parts cut away;
FIG. 2 is a graph showing burning rates of several examples.
Referring to FIG. 1, the specific embodiment of a heater 1
comprises a container 2 which consists of a body 3 and a
cylindrical lower end 4. The body 3 of the container is made of a
combustible material such as paper and the like. Around the outside
of the body 3 is a light-gauge metal foil 5. The container 2 is
filled with a wax 6, which is solid at room temperatures. On top of
wax 6, a mat 7 of inorganic microfibrous material is placed. The
mat 7 may conform to the shape of the lower end 4 of the
container.
Suitable containers for the composition can be prepared in a manner
well known in the art of container manufacture from paper stock,
cardboard, fiberboard and the like. More specifically, it has been
found that suitable containers include corrugated paper or seamless
cardboard containers that may be externally covered with a
light-gauge metal foil (e.g. aluminum) or externally coated with a
fire-resistant coating such as a sodium silicate or an ammonium
dihydrogen phosphate or a fire-resistant paint. These coatings may
be applied to the container by spraying, dipping, painting or a
combination of such methods.
In general the thickness of the metal foil around the outside of
the container can vary from about 0.0002 to about 0.005 inch. A
metal foil thinner than about 0.0002 inch or thicker than about
0.005 inch is not satisfactory for a heating composition designed
to provide adequate protection to crops and plants against cold
weather damage. Use of a thinner foil is likely to result in
collapse of the container sidewalls during the burning period. A
thicker foil will adversely retard the burning rate of the
composition since the container walls will not be consumed during
ignition at a rate sufficiently rapid to permit substantially free
access of air to the burning surface.
A particularly preferred container is a cylindrical open-top kraft
seamless convolute container with a wall thickness between about
0.01 to 0.08 inch having a 0.00035 -inch aluminum foil coating on
the outside thereof, and a metal bottom. The sidewalls of such a
container burn at a rate slightly less than the burning rate of the
composition and are consumed during ignition.
It has been found that untreated (nonchemically fire-resistant)
containers or nonmetallic foil-covered containers as well as
metallic containers (e.g. of the tin can type) are not satisfactory
containers for use in the present invention. The non-fire-resistant
or nonmetal foil containers burn too rapidly. The metal containers
provide erratic burning rates due to restricted air supply during
the latter stages of burning.
The particular size and/or shape of the heating composition of the
present invention is somewhat dependent on the particular end use
and the methods of manufacture. For example, if the heating
composition is to be used as an igniter to start a fire in an
outdoor grill or fireplace containing a combustible material, such
as wood, charcoal briquettes, coal and the like, including mixtures
thereof, then the fire-starting composition is preferably shaped to
expose a maximum surface area to the atmosphere, thus permitting
fairly rapid combustion of the igniter when lit. Preferred shapes
for fire starting are a square or rectangular tablet or pellet
since these configurations expose a greater surface area to the
atmosphere.
The heating composition also can be shaped in the form of a
relatively flat, thin wafer or tablet or elongated as a candle when
used for starting a relatively small fire.
The heating composition and the container therefor to protect
growing crops and plants also may be of any convenient size and/or
shape. In general it has been found that a substantially
cylindrical or rectangular shape is the most convenient and
satisfactory in most instances. The size is determined to a large
extent by the heat evolution and burning time desired, i.e. the
longer the desired burning time, the greater the depth and the
greater the heat evolution, the larger the surface area.
Alternatively, one can employ one or more of the smaller sized
compositions, igniting them at spaced intervals of time to
accomplish substantially the same results as with the more bulky
composition. It has been found that rectangular-shaped containers
measuring about 8 by 8 by 8 inches and filled nearly to the top
thereof with the composition of the invention including a petroleum
wax of about 150.degree. F. melting point will burn on an average
of about 8 -10 hours.
The wax component of the composition of the present invention can
be a natural animal or mineral wax, a petroleum wax, or a synthetic
wax as well as mixtures of any of the above types of wax.
The term "wax" in the specification and claims is employed in a
generic sense to define both natural waxes, synthetic waxes and
substances chemically similar to waxes, wax substitutes and wax
equivalents. Among such substances are the hydrocarbon waxes
including ceresin, ozocerite, and microcrystalline types such as
wax tailings, mineral beeswax, and the like, vegetable waxes such
as carnauba, montan and others, and animal waxes such as stearin,
stearic acid, beeswax, tallow, spermaceti and the like. Also,
synthetic waxes such as hydrogenated montan wax and higher
alcohols.
THe preferred wax component is a petroleum wax and may be a
paraffin or a microcrystalline wax or a mixture thereof. Such waxes
are normally solid at room temperature and are composed mainly of
long-chain aliphatic hydrocarbons.
The paraffin wax can be a crude slack wax that may be partially
refined, a scale wax, a refined wax or a mixture of such waxes. THe
microcrystalline wax can be a tank bottoms wax, a residual
microcrystalline wax or a mixture of such waxes. Typical physical
properties for a suitable paraffin wax include a melting point
temperature of 150.degree. F. and an oil content of about 15
percent.
Desirably, the melting point temperature of the wax used in the
present invention should be between about 100.degree. and
200.degree. F., preferably about 120.degree. to 180.degree. F., to
achieve fairly rapid melting of the wax and assist in spreading the
flame from the point of ignition to the adjacent exposed surfaces.
While waxes having a melting point temperature of less than
100.degree. F. and greater than 200.degree. F. can be used, such
waxes do not perform as well as the 120.degree. to 180.degree. F.
melting point temperature waxes in the composition of the present
invention.
The fibrous material component can be an inorganic substantially
noncombustible microfibrous material or an organic nonfusible
microfibrous material or mixtures thereof.
The inorganic substantially noncombustible microfibrous material
can be of the inorganic microfibrous type such as asbestos, glass,
rock wool and the like including mixtures thereof. Effective
inorganic microfibrous materials include glass fibers of various
types, such as soda-lime glass fibers, borosilicate (Pyrex) fibers
and lead glass fibers, asbestos fibers and quartz fibers. These
inorganic microfibers are at least substantially insoluble in and
nonreactive with most liquid hydrocarbons.
A preferred type of microfibrous material are chrysotile asbestos
microfibers of the Group 7 Milled Fibers as classified by the
Quebec Asbestos Producers Association. A particularly preferred
type of glass microfibers are Johns-Manville Code Numbers 102 and
104. Johns-Manville glass fibers Codes 106, 108, 110 and 112 can
also be used.
It is desirable to employ inorganic microfibers having an average
fiber diameter not greater than about 5.0 microns, preferably
between 0.01 and 4 microns in diameter for the most consistent
results. THe use of inorganic microfibrous materials having
diameters greater than about 5 microns tends to give erratic
spreading of the flame in the fire-starting embodiment.
A satisfactory range in a fire igniter for the glass microfibers is
from about 0.2 to about 2 percent by weight when the smaller
diameter glass microfibers are used and at least 1 percent when
glass microfibers above 0.75 micron are used. A satisfactory range
for glass microfibers is from about 0.5 to about 15 percent when
the heating composition is in the container. A satisfactory range
for asbestos microfibers in a fire igniter is from 2 to 10 percent,
while in the container, a satisfactory range is from about 5.0 to
about 25 percent by weight, preferably 10 to 15 percent by
weight.
The organic nonfusible microfibrous materials can be obtained from
cotton linters, woodpulp such as newsprint pulp, sawdust, wood
shavings, reconstituted cellulose, such as rayon, or mixtures
thereof. The organic microfibrous material must be of the
nonfusible type to perform in a satisfactory manner in the heating
composition of the present in invention. Organic fusible fibrous
materials such as "Dacron," polypropylene and "Orlon" microfibers
are representative of the fusible type of organic fibers. These
materials will not perform satisfactorily in the composition of the
invention because they do not permit the flame to spread from the
point of ignition of the composition to the remaining exposed
surface and/or the flame to continue to burn after spreading to the
relatively adjacent surfaces. A preferred type of an organic
nonfusible microfibrous material is microfibrous cotton
linters.
The organic nonfusible microfibers may have an average diameter
between about 1 and about 100 microns, but a range between 10 and
25 microns has been found most suitable in many instances.
Excellent results have been attained with cotton linters having an
average fiber diameter of about 15 microns.
The average length of the organic nonfusible microfibers can vary
from about 0.05 to about 20 millimeters. Use of lengths in the
range between 2 and 5 millimeters are particularly preferred for
rapid spreading of the flame about the exposed surface of the
finished composition.
A satisfactory range for the organic nonfusible microfibers in the
composition is from about 2 up to about 25 percent by weight. Use
of amounts less than about 2 percent by weight, does not provide
satisfactory flame-spreading properties while amounts in excess of
about 25 percent by weight are economically unattractive besides
being hard to incorporate. It is to be stressed that the percentage
of the microfibrous material in the composition is based on the
overall weight of the composition.
When the heating composition is used as a fire starter the
microfibrous material must be dispersed throughout the wax to
permit rapid spreading of the flame to the exposed surfaces. If the
microfibrous material is concentrated at or near one or more
exposed surfaces the flame will not spread rapidly to the remaining
surfaces and the more difficulty combustible materials will not be
as easily ignited.
The heating composition of the invention can be prepared for use in
several ways. For example, the container can be substantially
filled with the hot wax material, and during cooling the
microfibrous material can be added thereto so as to concentrate the
fibers in or near the exposed end portion of the wax.
Alternatively, the microfibers can be placed in the empty
container, then the wax added and allowed to cool. The end portion
of the container near the fibers is removed and a cap or suitable
sealing means placed on the other end of the container. A still
further modification comprises filling the container almost full of
wax and, after a cooling period, adding on top a slurry of the wax
and microfibrous material. A preferred method, particularly when
glass fibers are used comprises filling the container with wax and
adding a mat of glass wool to the partially cooled wax so that the
mat is in contact with or partially embedded in the exposed surface
of the wax. This method is particularly effective when the glass
wool pads are from about 0.5 to 3 inches in thickness. Prior to
placing the shaped mat in the container, one may insert a thin
layer of paper or cardboard on the top of the wax to support the
mat on the wax during the time it takes for the wax to
solidify.
In filling the container with the composition, one may also mold
the wax separately, shape or form the microfibrous material mat
separately, place the molded wax in the container, and add the
shaped mat of microfibrous material thereto. THe microfibrous mate
can be brought into contact with the upper wax surface just prior
to the time the composition is ignited.
The composition of the present invention provides satisfactory
protection to growing crops and plants when the microfibers are
distributed through the wax but the most effective compositions for
this purpose are those wherein the bulk of the microfibers are
concentrated at or near an exposed surface of the composition, i.e.
the top 25 percent of the space occupied by the wax. Such a
composition lends itself to ease of ignition and ease of
manufacture and its burning rate is more uniform. Equally good
results are obtained using the microfibrous mat of fibers which is
in contact with or initially is separated from the wax surface by a
thin layer of paper or the like, but which on ignition of the
composition come in intimate contact with the burning wax.
THe composition of the invention can be ignited in a known manner
such as, for example, by use of a match, a blowtorch, and the like.
It has been found that the covered heating composition can be
readily ignited by pouring into the container a small amount of a
volatile, flammable fuel such as a 50/50 mixture of isooctane and
kerosene and applying a lighted match or taper thereto.
Following is a description by way of example of methods of carrying
out the practice of the present invention.
EXAMPLE 1
There was introduced into a Waring Blendor 97 grams of a refined
petroleum paraffin wax, Petroleum Wax D, having a melting point
temperature range of 125.degree. - 127.degree. F. and an oil
content of less than 5 percent and 3 grams of cotton linters
microfibers having an average diameter of about 15 microns. The
admixture was heated to a temperature of about 150.degree. F. with
stirring as the wax became liquefied. The stirred mixture was
poured into a cylindrical-shaped mold having a diameter of
approximately 2 inches and a height of about 3.5 inches and allowed
to cool. The cooled composition was removed from the mold and a
lighted match applied to one edge of the molded composition. The
flame spread over the composition until the exposed surfaces were
burning.
EXAMPLE 2
Following the procedure of example 1, above, another composition
was prepared from an admixture of 93 grams of the same Petroleum
Wax D and 7 grams of chrysotile asbestos, Johns-Manville grade 7R-
06. The mixture was liquefied and cast into a block about 4 inches
square and 2 inches high. From this cast block, smaller blocks
about 2 inches high and 1 inch square were cut. One of the smaller
blocks was ignited by a lit match held against one corner. The
flame rapidly spread over the block.
EXAMPLE 3
There was introduced into a Waring Blendor 199 grams of a Petroleum
Wax D. The wax was liquefied by applying external heat to the
blendor and then there was added 1 gram of finely divided
microglass fibers, sold under the trade name J-M 102. The resulting
mixture was stirred for 1 minute to distribute the fibers randomly
in the wax. The stirred mixture was then poured into a 150-ml.
glass beaker and allowed to cool. The resulting solid,
cylindrical-shaped mass was removed from the beaker; a small hole
was made in the middle of one end and a cotton yarn candle wick 0.5
inch in length was inserted therein.
The resulting candle was placed in a circular metal pan 23/8 inches
in diameter and three-eighths of an inch high. A lighted match was
applied to the wick and within a few minutes the resulting flame
had spread over the entire exposed surface. The height of the flame
after the entire exposed surface was ignited amounted to about 12
inches. Considerable heat developed during the 30 -minute burning
period. After all of the wax had been consumed there remained an
ash residue of glass fibers.
EXAMPLES 4 TO 20, INCLUSIVE
Following the procedure of example 3 above, additional
fire-starting compositions were prepared in a similar manner using
various amounts of wax of various types and with varying
percentages of different kinds of fibrous materials. Particulars as
to the compositions of these examples are shown in the tables
below.
Tables I and II below summarize the results of tests performed on
the fire-starting compositions prepared in accordance with examples
1 to 20, inclusive. In addition, the tables show the percentage
composition of the various components. No wick component was
present in either of the fire-starting compositions of examples 1
and 2. The size of each of the fire-starting compositions of
examples 3- 20 was approximately 13/4 inches in diameter and 3
inches in height. The wick inserted in the compositions of these
examples was approximately three-fourths of an inch in length.
##SPC1## ##SPC2##
Inspection of the results in table I above shows that the heating
compositions of the present invention are effective in spreading a
flame across the entire exposed surfaces thereof. Moreover, the
data show that the combination of glass microfibers of relatively
small diameters, i.e. below 0.75 micron, in amounts of 0.2 percent
or more are effective, whereas the use of less than about 0.2
percent of glass fibers of the same size (example 7) does not
produce satisfactory results. The data also show that it is
necessary to employ more than 1 percent by weight of asbestos
microfibers (example 5) or more than 0.5 percent of glass
microfibers (example 10) of relatively large diameter in the
compositions in order to obtain satisfactory spreading of the flame
from the wick across the surface of the composition. The data in
the table further illustrate (example 2) that a wick component is
not required to spread the flame across the exposed surfaces of the
composition.
The results shown in table II above illustrate the effectiveness of
the specific organic nonfusible microfibrous materials to spread
the flame from an ignited portion of the composition across the
exposed surfaces thereof.
Examples 1, 12 and 13 demonstrate that amounts of cotton linter
microfibers above 2 percent are satisfactory whereas an amount of 1
percent or less (example 14) is not effective to spread the flame.
Example 1 further shows that the composition does not require a
wick component for effective flame spreading.
Examples 16 to 19 inclusive demonstrate that other organic
microfibrous materials of the fusible type, such as "Dacron,"
"Orlon" or polypropylene microfibrous materials are not effective
materials for use in the compositions of the present invention.
These materials cause the flame to extinguish before spreading
across the exposed surfaces of the composition.
The composition of example 17 was unsatisfactory because the flame
was extinguished when the fibers reached their fusion point. In a
similar manner the "Orlon" fibers in the composition of example 19
fused, shortly after the flame from the wick spread to them with
the resultant formation of a crust on the exposed surfaces adjacent
thereto. The crust prevented the flame from spreading and in a
relatively short time it was extinguished.
Example 20 illustrates the utility of mixtures of inorganic fibers
and nonfusible organic fibers in preparing the compositions of this
invention.
EXAMPLE 21
The out-of-doors utility of the heating composition of the present
invention as a fire starter was tested outside on a moderately
windy day using the composition of example 8 modified by the use of
Petroleum Wax D in place of the microcrystalline wax of example 8.
The composition was placed on the bare ground, rather than on a
pan, and was protected on one side only by a foot-high partition.
After ignition the flame spread over the whole exposed surface. The
composition burned to completion and was not extinguished by a
number of strong wind gusts. The relatively small amount of wax
which ran down the sides was absorbed in the surrounding soil.
EXAMPLE 22
A single layer of conventional egg-shaped charcoal briquettes was
placed on the bottom of a cylindrical wooden basket 91/2 inches in
diameter at the top, 81/2 inches in diameter at the bottom and 51/4
inches high. In the middle of this layer of briquettes was placed a
11/2 inch cube of the wax-fiber composition of example 2, having
inserted in its upper surface a T-shaped strip of wax-impregnated
blotting paper. The wax-fiber igniter was then surrounded by
charcoal briquettes until only about one-half inch of the
wax-impregnated paper strip protruded above the charcoal. A
tight-fitting paper cover having a slot in the center was then
fitted over the top layer of charcoal so that the wax-impregnated
paper strip protruded through the slot. When ready for use, the
wax-impregnated paper strip was ignited. This ignited the paper
cover and at the same time transmitted the flame to the wax-fiber
igniter. The charcoal was ignited from the inside and eventually
the basket burned and was consumed. After about 20 -25 minutes a
bed of burning charcoal, suitable for cooking, remained.
A further embodiment of this example comprises the combustible
container without the close-fitting cover, wherein one end of the
wick is in the heating composition and the other end thereof
extends at least to the upper level of the charcoal briquettes in
the container.
EXAMPLE 23
A blend of 49 percent by weight of Petroleum Wax A and 51 percent
by weight of Petroleum Wax B was prepared. A 1 gallon motor oil can
"RC Foil Kan" 6.5 inches in diameter by 7.75 inches high was filled
with a molten blend of 3,000 parts by weight of the wax mixture and
158 parts by weight (5.27) percent of Johns-Manville Paperbestos
No. 3 asbestos fiber (Group 7 of Quebec Asbestos Producers
Association). The sides of the container were made of heavy paper
covered with aluminum foil 0.00035 inch thick (inside and out). The
bottom was tinplate. The net weight of the filled can was
approximately 7.5 pounds. Wax A melted at about 124.degree. F. and
Wax B at 132.degree. F.
EXAMPLE 23A
Example 23 was repeated using a motor oil can "Foil Kan" that had
the aluminum foil removed from the inside surface. The net weight
of the filled can was about 7.5 pounds.
EXAMPLE 23B
The filled cans of example 23 and 23A were ignited outdoors and
weighed at hourly intervals. The can of example 23A burned for 7
hours at an hourly rate ranging from 1.5 pounds during the first
hour to 0.75 pound during the seventh hour. The can of example 23
showed a rate of 1.5 pounds for the first hour and only 0.25 pound
for the seventh hour. After 7 hours the example 23 can still
contained considerable unburned wax in contrast to the example 23A
can which contained only about 30 grams unburned wax. The
relatively unsatisfactory result for the example 23 container was
apparently due to the failure of the container sides to
disintegrate on burning, because of the extra thickness of aluminum
foil separated by the thickness of the container wall. The inner
aluminum foil acted like insulator for the container walls, which
carbonized and also acted as an insulator. The walls of the
container coated on the outside only with foil collapsed and were
consumed during the period of ignition.
EXAMPLE 24
A rectangular-shaped corrugated paper box 63/4 inches wide .times.
8 inches long .times. 63/4 inches high was covered on the outside
with 0.0015 -inch-thick aluminum foil. Hot Petroleum Wax C in an
amount of 3,200 parts by weight was poured into the box and cooled
to room temperature. A hot slurry, composed of 225 parts
Paperbestos No. 3 and 1,075 parts of petroleum Wax C, was poured on
the upper surface of the wax in the container and allowed to cool.
The concentration of asbestos in the upper layer was 17.3 percent
by weight (equivalent to 5 percent in the overall wax-asbestos
blend).
EXAMPLE 24A
Example 24 was repeated except that all of the asbestos (225 parts
by weight) and all of the Wax C (4,275 parts by weight) were
intimately mixed at a temperature of about 160.degree. F. and
charged to the container. The container was cooled to room
temperature. The concentration of asbestos in the mixture was 5
percent by weight.
EXAMPLE 24B
Example 24A was repeated except that no fiber was incorporated.
Only Wax C (4,275 parts by weight) was charged to the container and
cooled to room temperature.
EXAMPLE 24C
The containers of examples 24, 24A and 24B were ignited and burned
outdoors. The respective burning rates are shown in FIG. 2 of the
accompanying drawing. The container of example 24 gave a
substantially uniform rate for the first 5 hours of burning and
continued burning for a total of 7 hours. The container of example
24B shows relatively erratic rates especially after 2 hours. The
desirability of concentrating the fiber component near the burning
surface (upper 25 percent of the wax) is evident from the results
with example 24. The results with example 24A show that dispersing
the microfibers throughout the wax increases the burning rate for
the first hour which is desirable for lighting a fire and producing
a considerable amount of heat and light.
EXAMPLE 25
EXample 24 was repeated except that the top layer consisted of
1,075 parts of Petroleum Wax C and 140 parts of Paperbestos No. 3.
This reduced the concentration of asbestos in the upper layer to
11.5 percent (equivalent to 3.2 percent in the overall wax-asbestos
blend), while leaving the thickness essentially unchanged from
example 24.
EXAMPLE 25A
The container of example 25 was burned outdoors and the burning
rate thereof was satisfactory. Considerable windiness between the
third and sixth hours resulted in a moderate increase in the
burning rate for the container of example 25. This example
demonstrates that reducing the asbestos content of the top layer
from 17.2 percent to 11.5 (example 24 vs. example 25) did not
adversely affect the burning rate.
EXAMPLE 26
Example 24 was repeated except that the top layer consisted of a
hot slurry of 1,075 parts Petroleum Wax C and 225 parts SOLKA FLOC,
a commercial grade of wood cellulose having an average fiber
diameter of about 20 microns. After cooling to room temperature,
the container was taken outdoors and ignited in the usual way with
20 ml. of a 50/50 blend of isooctane/kerosene. It burned
satisfactorily in a moderate breeze for 7 hours.
EXAMPLE 27
A corrugated paper box like the one used in example 24 with no
aluminum foil covering was coated on the outside with two coats of
a commercially available fire-retardant paint containing antimony
oxide and calcium carbonate (DU Pont Fire Retardant Flat Paint 2101
Ivory). The contents of the treated container were the same as in
example 24. The container burned outdoors for 61/2 hours in a
satisfactory manner.
EXAMPLE 28
A corrugated paper box of the size shown in example 24 with no
aluminum foil covering was dipped in 40.degree. sodium silicate
solution and allowed to dry. It was then filled with approximately
4,500 grams of a molten slurry of 93 percent by weight of Petroleum
Wax C and 7 percent by weight of type 7RO6 asbestos fiber,
uniformly dispersed. A similarly filled container was prepared
using an untreated box of the same type. The containers were
ignited outdoors using a propane torch. After about 2 hours the
untreated box was burning at an excessive rate and was ready to
disintegrate. It was therefore extinguished. The
sodium-silicate-treated container burned satisfactorily for 5
hours, at which time the wax was almost completely consumed.
EXAMPLE 29
The container of example 23A was filled with a molten blend of
2,250 parts by weight of Petroleum Wax C and 2.25 parts by weight
of dicyclopentadienyl iron (ferrocene) and cooled to room
temperature. A hot slurry of 750 parts Petroleum Wax C, 0.75 part
ferrocene and 158 parts Paperbestos No. 3 was poured on top of the
solidified wax in the container. When the cooled container was
ignited outdoors with isooctane/kerosene it burned at a
satisfactory rate for 12 hours, during which time significantly
less smoke was evolved.
EXAMPLE 30
A cardboard box 41/2 inches .times. 41/2 inches .times. 4 inches
deep was coated on the outside with 0.0015 -inch-thick aluminum
foil. It was filled with 900 grams molten Petroleum Wax C and
cooled to room temperature. A piece of felt made of glass fibers
about 8 microns in diameter was placed on top of the solidified wax
and enough molten Wax C to wet the felt mat was poured on. The
dimensions of the mat were 41/4 inches .times. 41/4 inches .times.
one-half inches thick. The container was ignited outdoors and
burned for 6 hours at a satisfactory rate.
EXAMPLE 31
A corrugated paper box of the type used in example 24 was coated on
the outside with aluminum foil having a thickness of 0.0007 inch.
Into the box was poured 3,250 parts by weight molten Petroleum Wax
C. After cooling the container to room temperature, a molten slurry
of 1,075 parts Wax C and 225 parts sawdust was poured onto the
solidified wax in the container. After cooling again to room
temperature, the box was ignited outdoors with isooctane/kerosene.
It was slow to ignite but when ignited burned satisfactorily at a
somewhat lower burning rate for 9 hours than the container of
example 24.
EXAMPLE 32
A cardboard box 6 inches .times. 6 inches .times. 4 inches deep was
covered on the outside with 0.0015 -inch-thick aluminum foil. A
quantity of Wax C was heated above its nominal melting point of
150.degree. F. and was then continuously stirred in a vessel
equipped with counterrotating, side-scraping paddles. The vessel
was gradually cooled until the wax temperature was 125.degree. F.
At this point the wax was readily pourable having a consistency
like that of cake batter. The above box was filled with 1,420 parts
of the stirred wax and a53/4 inch square of blotter paper was
placed on the surface of the still semifluid wax. Immediately
thereafter, a molten slurry of 442 parts Wax C and 58 parts
Paperbestos No. 3 was poured onto the blotter paper. By this
technique the container was filled and layer separation was
achieved with none of the waiting required for cooling when molten
wax at 160.degree. -170.degree. F. is used.
The container was burned outdoors and performed satisfactorily.
EXAMPLE 33
A field test was carried out with the container prepared as
described in example 24.
One container was positioned on the ground within about 1 foot of
the trunk of a grapefruit tree, and another container was placed on
the ground on the other side of the tree about the same distance
from the trunk. The tree was about 15 feet high and its lower
branches were about 3 feet above the ground at the trunk.
Thermocouples had been placed at various points on the test tree
and also on a similar tree about 30 feet away in order to obtain
temperature increase data.
The two containers were ignited using a lighting torch commonly
employed in citrus groves and the flames were allowed to reach an
equilibrium condition. Temperature rises of from 3.degree. to
13.degree. F. were observed at various points throughout the tree
as compared with an adjacent unheated tree. These temperature rises
were judged sufficient to protect the tree against damage by cold
weather and also against the loss of fruit due to frost.
* * * * *