US20080083159A1

US20080083159A1 - Synthetic firelog and method for making same

Info

Publication number: US20080083159A1
Application number: US11/870,239
Authority: US
Inventors: John B. Doepker; Thomas C. Doepker
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-10
Filing date: 2007-10-10
Publication date: 2008-04-10

Abstract

A synthetic firelog is made from substantially 100% leaves mixed with a binder. Preferably, the synthetic firelog is comprised of a base material that is substantially 100% tree leaves. The leaves may be from any of a variety of trees, including, but not limited to, oak, maple, poplar, or birch trees, or mixtures thereof. Most preferably, the leaves consist primarily of oak tree leaves. However, it will be appreciated that numerous varieties of tree leaves, and mixtures thereof, may be used. The binder is a wax material, preferably paraffin wax. A method for making the synthetic firelog is disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/850,566, entitled “Leaf Log and Method of Producing the Same,” filed on Oct. 10, 2006.

BACKGROUND OF THE INVENTION

The present invention relates generally to a synthetic firelog made from waste organic matter. More particularly, the present invention relates to a synthetic firelog, and a method for making same, comprised of substantially 100% tree leaves mixed with a binder.
Synthetic firelogs are well known in the prior art and have been sold commercially for years. The earliest synthetic firelogs were comprised of a sawdust base material mixed with a binder, such as wax. However, numerous sawdust substitutes have been used over the years, and synthetic firelogs made from various cellulosic materials, such as wood pulp, paper, cardboard and the like (often obtained as by-products or residues from industrial or agricultural operations) mixed with a wax binder, have been developed.
For example, U.S. Pat. No. 3,297,419 describes the use of rice hulls or shredded paper. U.S. Pat. Nos. 3,843,336 and 3,880,611 disclose the use of reclaimed pulp and Northern Kraft paper beater stock, respectively. U.S. Pat. No. 4,040,796 teaches firelogs composed of ground bark and peanut shells. U.S. Pat. No. 4,043,765 describes firelogs comprises of crushed nut shells, straw, paper pulp, and cotton waste, and U.S. Pat. No. 4,120,666 discloses the use of shredded newsprint.
Other synthetic firelog compositions include: sawdust splinters, cotton linter and charcoal powder, as taught by U.S. Pat. No. 4,302,210; bagasse, chopped straw, waste paper in pulp, shredded or flaked form, sphagnum moss, nut shells, coffee grounds, fibrous residue left after fruit or vegetable juice extraction, cotton waste and bark, disclosed in U.S. Pat. No. 4,326,854; and, green sawdust, coal liquid, and sorghum, described in U.S. Pat. No. 4,333,738.
Additionally, some prior art synthetic firelogs use combinations of various yard waste, such as tree branches, grass and leaves, mixed with a binder. Such synthetic firelogs, and methods of producing the firelogs, are described in U.S. Pat. Nos. 4,102,653; 4,326,854; 4,333,738; 6,136,054; 5,393,310; and, 6,719,816. Formation of such synthetic firelogs, as discussed in the preceding patents, typically involves mixing various cellulosic materials at prescribed percentages, adding a heated (melted) binder material, mixing the binder material with the cellulosic materials, compressing the mixture into a cylindrical mold to form a generally log-shaped structure and allowing the mixture to cool.
Optionally, chemicals that impart specific scents, aromas or sounds (such as crackling) to the synthetic firelogs may be added, such as those disclosed by U.S. Pat. Nos. 6,602,306 and 4,818,249.
While numerous materials and combinations of materials have been used in the prior art as the base materials for synthetic firelogs, to the applicants' knowledge, the prior art has not developed a synthetic firelog comprised of substantially 100% tree leaves as a base material. The closest analogous prior art is U.S. Pat. No. 5,393,310 issued to Wollen, identified above.
The Wollen patent discloses a method for making an artificial fireplace log comprising the steps of mixing grass clippings and leaves taken directly from a lawn without further processing, in an amount from 60% to 80%, by weight, of the total weight of all materials, with wood chips and sawdust in an amount from 10% to 15%, by weight of the total weight of all materials. The grass clippings and leaves mixture preferably comprises 50% grass clippings and 50% leaves. A binder material is added in an amount in the range of 5% to 10%. The binder material is selected from a group consisting of resin glues and waxes in liquid.
The Wollen patent teaches a mixture of grass clippings, leaves, wood chips and sawdust as the base material for its artificial fireplace log. As Wollen notes, such a composition may be useful in light of the many communities that require residential property owners retain all yard waste, including grass clippings, leaves, and twigs, and either compost them, or ship them to a central composting location.
However, it would be even more useful and beneficial if the base material for a synthetic firelog was comprised of substantially 100% tree leaves. First, tree leaves are a renewable resource that are available in abundance. Lawns and forests provide an ample supply of leaves that otherwise would be undesirably deposited in landfills or burned outdoors. Additionally, creating a synthetic firelog from leaves preserves the trees themselves. Thus, the trees may continue to produce new leaves season after season while deforestation is desirably reduced. Lastly, forming a synthetic firelog of a base material comprised of substantially 100% tree leaves, without the inclusion of significant amounts of other yard waste or sawdust, would simplify the manufacturing process, reduce costs and create a firelog having a more uniform and predictable burn.
Accordingly, there is a need for a synthetic firelog formed from a base material comprised of substantially 100% tree leaves. Desirably, the synthetic firelog is comprised of substantially 100% tree leaves mixed with a paraffin wax binder. More desirably, the synthetic firelog produces a uniform and predictable burn. Most desirably, the synthetic firelog may be formed in a variety of diameters and lengths so the firelog may be used in numerous applications, such as fireplaces, fire pits, wood burning stoves, pellet burning stoves and the like.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a synthetic firelog made from substantially 100% tree leaves along with a binder, and a method of making same. The synthetic firelog is comprised of a base material that is substantially 100% tree leaves. The leaves may be from any of a variety of trees, including, but not limited to, oak, maple, poplar, or birch trees, or mixtures thereof. The binder is a wax material, preferably paraffin wax.
The synthetic firelog preferably is comprised of about 50%, by volume, leaves and 50%, by volume, binder, although other leaf/binder compositions are possible depending upon the desired burn time and the shape and size of the firelog. The synthetic firelog may be formed in any number of shapes and sizes, but a typical synthetic firelog is formed in a generally cylindrical shape about 14 inches long and about 4 inches in diameter. Other lengths, diameters and shapes are possible, including pellets, depending on the desired use and burn time. In some embodiments, the synthetic firelog of the present invention may include additives to create a desired scent or aroma when the firelog is burned.
A method for making synthetic firelog of the present invention includes the steps shredding a quantity of dried leaves, mixing with a quantity of liquid binder until the binder coats the mixture, compressing the mixture in a mold to form a compacted mass, extruding the compacted mass in the desired shape and with the desired dimensions and allowing the extruded compacted mass to cool and harden.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:

FIG. 1 is perspective view of the synthetic firelog of the present invention;

FIG. 2 is a block diagram of the various steps in a method for making the synthetic firelog of the present invention;

FIG. 3 is a sectional view of the screw extruder employed in the process of the making the synthetic firelog of the present invention; and,

FIG. 4 is a sectional view of the piston chamber employed in the process of making the synthetic firelog of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.
It should be further understood that the title of this section of this specification, namely, “Detailed Description of the Invention,” relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
Referring now to the drawings, in which similar or corresponding parts are identified with the same reference numeral, and more particularly to FIG. 1, there is shown a synthetic firelog 1 made in accordance with the present invention.
Synthetic firelog 1 is comprised of substantially 100% tree leaves as a base material, mixed with a binder. The leaves may be from any of a variety of trees, including, but not limited to, oak, maple, poplar, or birch trees, or mixtures thereof. Preferably, the binder consists of a paraffin wax.
It has been found that oak leaves, in particular, are quite suitable for use as a base material for synthetic firelog 1 of the present invention since oak leaves tend to be dryer, or tend to dry faster, than other tree leaves. However, it will be appreciated that many different types of tree leaves are suitable for use as the base material of synthetic firelog 1 of the present invention, and all such tree leaves, and mixtures thereof, are included within the scope of this disclosure.
As those skilled in the art will recognize, negligible amounts of grass, sticks or other organic yard waste or natural materials may be present in the base material depending on the source of the leaves. For example, leaves collected from municipalities that have been raked from homeowners' lawns and city properties may contain small amounts of other yard waste (dead grass, twigs, etc.), while leaves collected from a forest floor may contain small amounts of other organic materials (seeds, twigs, etc.). However, the amounts of these non-leaf materials typically are negligible and have no significant effect on the performance or qualities of synthetic firelog 1.
Along those lines, it will be recognized that, while paraffin wax is the preferred binder for synthetic firelog 1, other types of wax, such as refined wax, petroleum wax and commercial wax, may also be utilized both as a binder and to provide fuel for the continual burning of the firelog.
In the preferred embodiment, synthetic firelog 1 is comprised of a mixture of approximately 50%, by volume, shredded tree leaves as a base material and approximately 50%, by volume, paraffin wax as a binder and combustion controller. The tree leaves preferably are shredded to a size of approximately 1 to 3 inches. This may be done using a shredder or mulcher as is known in the art and as is commonly used for lawn maintenance.
It has been found that this composition results in a synthetic firelog having an attractive appearance, an attractive flame while burning and a sufficiently long burn time.
For example, using the preceding composition, a sample synthetic firelog made according to the principles of the present invention was formed in a generally cylindrical shape, having a length of about 14 inches and a diameter of about 4 inches. The firelog weighed approximately 3 pounds, yielding a density of about 30 pounds per cubic foot. The sample log desirably burned for approximately 2 hours and produced an aesthetically attractive flame.
However, those skilled in the art will recognize that various shapes, dimensions, compositions and densities of synthetic firelog 1 are possible without departing from the scope of the present invention.
For example, while synthetic firelog 1 preferably is generally cylindrical in shape and is formed to mimic the size and appearance of a traditional wood firelog, other shapes, such as rectangular or box-like shapes, are possible if needed for specific uses. Similarly, while a 14 inch length and a 4 inch diameter are fairly standard dimensions for prior art artificial firelogs, synthetic firelog 1 may be formed in numerous other lengths and diameters as dictated by the desired use and burn time.
Along those lines, synthetic firelog 1 may also be formed as a pellet, having a relatively small length (approximately ½ inch) and a small diameter (approximately ¼ to ½ inch). As a pellet, the synthetic firelog of the present invention may be used in pellet stoves, central heating furnaces and other heating appliances that use pelletized fuel.
The pellets may be formed by the methods disclosed in the instant application, by cutting larger synthetic firelogs formed according to the present invention or by other pellet formation means as are known to those skilled in the art. When the synthetic firelog of the present invention is to be formed as a pellet, it will be appreciated that the tree leaves used as the base material must be shredded to a smaller size than previously described herein, perhaps on the order of about 1/16 inch to ⅛ inch, or smaller.
Additionally, it may be desirable to increase or decrease the desired burn time by increasing or decreasing the amount of paraffin wax binder in the composition of synthetic firelog 1, or by substituting a different wax binder for the preferred paraffin wax binder. Therefore, the density of synthetic firelog 1 of the present invention may vary and may preferably range from about 10 pounds per square foot (or lower) to about 40 pounds per square foot (or higher).
In some embodiments, synthetic firelog 1 may also include additives to create a desired scent or aroma when the firelog is burned. Such additives are well known to those skilled in the art.
All such variations in the shape, dimensions and composition of synthetic firelog 1 are included within the scope of the present disclosure.
As shown in FIG. 2, the preferred method to manufacture of synthetic firelog 1 of the present invention comprises five primary steps, including shredding a collection of dried leaves, mixing with a liquid binder until the binder coats the mixture, compressing the mixture in a mold to form a compacted mass, extruding the compacted mass in the desired shape and with the desired dimensions and allowing the extruded compacted mass to cool and harden.
First, a collection of dried leaves is shred to a desired size. As discussed above, the leaves may be from any of a variety of trees, including, but not limited to, oak, maple, poplar, or birch trees, or mixtures thereof. Most preferably, the leaves consist primarily of oak tree leaves. However, it will be appreciated that numerous varieties of tree leaves, and mixtures thereof, may be used.
The leaves may be obtained from various sources, such as from municipalities that collect leaves from residential properties or from forests. As noted above, negligible amounts of grass, sticks or other organic yard waste or natural materials may be mixed in with the leaves depending on the source of the leaves. However, the amounts of these non-leaf materials typically are negligible and have no significant effect on the performance or qualities of the synthetic firelog of the present invention.
If the leaves are wet, the leaves preferably are dried using techniques known to those skilled in the art, such as by spreading them out under the sun or by passing air through the leaves as they are stored in a storage vessel. However, the leaves preferably should not be so dry that they crumble into very fine dust particles when handled.
The collection of dried leaves is then passed through a shredder device. Any number of shredders or mulchers as are known in the art and as are commonly used for lawn maintenance may be used. The tree leaves preferably are shredded to a size of approximately 1 to 3 inches (as noted above, for creating a pelletized synthetic firelog, the leaves should be shredded to a smaller size).
A predetermined quantity of dried, shredded leaves is then mixed with a heated liquid binder until the binder coats the mixture. The mixture is compressed in a mold to form a compacted mass. The compacted mass is then extruded in the desired shape and dimensions and allowed to cool and harden, thereby forming the synthetic firelog of the present invention.
In one embodiment, the method for forming a synthetic firelog according to the principles of the present invention can be accomplished using a screw press 10 as shown in FIG. 3.
A predetermined quantity of shredded dry leaves 11 is fed into a hopper 12 where the leaves are introduced into a screw chamber 13. A predetermined quantity of paraffin wax is heated using a heater (not shown) to temperature suitable to liquefy the wax (typically 120-160 degrees Fahrenheit) and is added to screw chamber 13 through port 14. In the preferred embodiment, the quantity of wax is approximately equal to the quantity of leaves, as discussed above.
Leaves 11 are mixed with the wax in screw chamber 13 such that the wax coats leaves 11. This is accomplished by means of a flighted screw element 15 affixed on a rotating shaft 16. Shaft 16 is driven by a motor 17 that causes shaft 16 to rotate and screw element 15 to mix leaves 11 and the wax and to advance the mixture through screw chamber 13. The end of screw chamber 13 is tapered (shown at 19) and formed with an opening 19 through which the compressed mixture 20 is extruded.
Compressed mixture 20 is then allowed to cool and harden, after which is may be cut to the desired length to form the synthetic firelog.
In a second embodiment, the method for forming a synthetic firelog according to the principles of the present invention can be accomplished using a piston press 30 as shown in FIG. 3.
In this embodiment, a predetermined quantity of shredded dry leaves is mixed with a predetermined quantity of melted paraffin wax. In the preferred embodiment, the quantity of wax is approximately equal to the quantity of leaves, as discussed above.
The mixture of leaves and wax is introduced into a chamber 32 and a piston 33 is used to compress the mixture in chamber 32 to form a compressed mixture 31. Compressed mixture 31 may then be ejected from chamber 32 and permitted to cool and harden, after which is may be cut to the desired length, if necessary, to form the synthetic firelog.
All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.
In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.

Claims

1. A synthetic firelog comprising:

a base material; and

a binder;

wherein the base material is comprised of substantially 100% tree leaves, and wherein the binder is comprised of a wax.

2. The synthetic firelog of claim 1 wherein the tree leaves are shredded.

3. The synthetic firelog of claim 2 wherein the tree leaves are shredded to a size of about 1 to 3 inches.

4. The synthetic firelog of claim 1 wherein the tree leaves are selected from a group consisting of oak leaves, maple leaves, poplar leaves, birch leaves and mixtures thereof.

5. The synthetic firelog of claim 1 wherein the wax is a paraffin wax.

6. The synthetic firelog of claim 1 wherein the wax is selected from a group consisting of paraffin wax, refined wax, petroleum wax and commercial wax.

7. The synthetic firelog of claim 1 wherein a volume of the base material is about equal to a volume of the binder.

8. The synthetic firelog of claim 1 wherein a volume of the base material is different than a volume of the binder.

9. The synthetic firelog of claim 1 wherein the firelog is formed in a generally cylindrical shape.

10. The synthetic firelog of claim 1 wherein the firelog is formed as a pellet.

11. The synthetic firelog of claim 1 wherein the firelog has a density of about 30 pounds per cubic foot.

12. The synthetic firelog of claim 1 wherein the firelog has a density from between about 10 pounds per cubic foot to about 40 pounds per cubic foot.

13. A method for making a synthetic firelog comprising the steps of:

shredding a quantity of tree leaves to form a base material comprised of substantially 100% tree leaves;

melting a binder;

mixing a quantity of the base material with a quantity of the binder to form a mixture;

compressing the mixture to form a compacted mass;

extruding the compacted mass; and

allowing the extruded compacted mass to cool and harden.

14. The method for making a synthetic firelog of claim 13 wherein the tree leaves are shredded to a size of about 1 to 3 inches.

15. The method for making a synthetic firelog of claim 13 wherein the tree leaves are selected from a group consisting of oak leaves, maple leaves, poplar leaves, birch leaves and mixtures thereof.

16. The method for making a synthetic firelog of claim 13 wherein the binder is a paraffin wax.

17. The method for making a synthetic firelog of claim 13 wherein the binder is selected from a group consisting of paraffin wax, refined wax, petroleum wax and commercial wax.

18. The method for making a synthetic firelog of claim 13 wherein the quantity of the base material is about equal to the quantity of the binder.

19. The method for making a synthetic firelog of claim 13 wherein the quantity of the base material is different than the quantity of the binder.

20. The method for making a synthetic firelog of claim 13 further comprising the step of cutting the extruded compacted mass to a desired length.