US 3928677 A
A process of treating natural wood by heating the wood pieces in a bath of hydrocarbon, petrolatum or paraffin to a temperature which first expells the moisture and other gases from the wood products and then is cooled to fill the pores with the petroleum substance. The bath should be heated initially to a temperature of between 140 DEG C. and 180 DEG C. and then is cooled to the range of between 70 DEG C and 75 DEG C. The cooling bath may be the same or a different bath as desired.
Description (OCR text may contain errors)
United States Patent [191 Anthony Dec. 23, 1975 1 PROCESS OF TREATING WOOD Wilson B. Anthony, Auburn, Ala.
 Assignee: Firewood, Inc., Covington, Ga.
 Filed: Dec. 8, 1972  Appl. No.: 313,527
 US. Cl. 427/374; 44/40; 44/41; 427/393; 427/401; 427/441  Int. Cl. C10L 11/00; B05D 1/00; B05D 3/00;
B05D 1/18  Field of Search 117/147, 59, 149, 116; 44/40, 41; 427/393, 374, 401, 441
 References Cited UNITED STATES PATENTS 937,008 10/1909 Nelson 117/116 1,023,784 4/1912 Marr 117/116 1,121,645 12/1914 Marr 117/116 1,217,559 2/1917 Broady 117/116 1,235,895 8/1917 Herbein 117/116 1,382,103 11/1919 Lyon 117/116 1,572,905 2/1926 Stewart 117/149 1,648,294 11/1927 Coolidge 117/149 1,827,737 12/1927 C001idge.... 117/149 1,892,658 12/1932 Wiezevich 117/149 2,652,347 9/1953 Hudson 117/147 2,860,070 11/1958 McDonald 117/59 2,867,543 l/l959 Braun ..1 117/59 3,200,003 8/1965 Bescher 117/59 Primary Examiner-Michael R. Lusignan Attorney, Agent, or Firm-Burns, Doane, Swecker & Mathis  ABSTRACT A process of treating natural wood by heating the wood pieces in a bath of hydrocarbon, petrolatum or paraffin to a temperature which first expells the moisture and other gases from the wood products and then is cooled to fill the pores with the petroleum substance. The bath should be heated initially to a temperature of between 140C. and 180C. and then is cooled to the range of between 70C and 75C. The cooling bath may be the same or a different bath as desired.
10 Claims, 6 Drawing Figures U.S. Pateant Dec. 23, 1975 SheetlofZ 3,928,677
LIGHTER STRIPN US. Patent Dec. 23, 1975 Sheet 2 of2 3,928,677
PROCESS OF TREATING WOOD SUMMARY OF THE INVENTION followed by pulverizing and finally forming into bril5 quettes. Thus, it is a man-made product. It is granular in nature and provides pores or cavities after it is pressed into briquettes. It can be immersed in a liquid which will saturate the formed pores.
Sawdust, even if combined with a petroleum product and pressed into the form of a log, has the property of quick burning and leaves a substantial residue often accompanied by a considerable petroleum odor.
One object of this invention is to improve the process of treating natural wood as contrasted from both sawdust logs and charcoal briquettes to improve the effects obtained therewith, both the combustion properties and the finish.
Another object of the invention is to utilize natural wood to obtain a saturation thereof substantially throughout, with a suitable petroleum product such as paraffin to provide for ready combustion thereof or to improve the finish of the product as desired.
Still another object of the invention is to produce a fire log which will have provisions for immediate ignition or lighting and which will be useful for combustion with very little resultant ash.
These objects may be accomplished according to one embodiment of the invention by treating natural wood objects so as to obtain substantially complete saturation thereof with a petroleum substance such as paraffin. This is accomplished by initially heating the wood products in a bath of liquid petroleum such as paraffin to a temperature sufficient to expel] from the pores of the wood all moisture and gases contained therein and then to cool the wood products either in the same bath or in another bath in the liquid petroleum to effect an absorption'of the liquid in the pores of the wood products, substantially saturating the latter throughout. The wood products, if used for ignition, such as fire logs, may be enclosed in a suitable wrapper and provided with lighter strips at the opposite ends thereof to facilitate the initial combustion and complete burning of the log.
BRIEF DESCRIPTION OF DRAWINGS This embodiment of the invention is illustrated in the accompanyingdrawings, in which:
FIG. 1 is a diagrammatic side view of treating apparatus which may be used for dipping the products in the respective baths;
FIG. 2is a perspective view, with a part broken away, showing a fire log according to this invention;
FIG. 3 is a cross section therethrough on the line 3-3 in FIG. 2;
FIG. 4 is a detail cross section through the lighter strip;
FIG. 5 is'a perspective view of a fire log of a different shape made of natural wood and split and illustrating an application of this invention thereto; and
FIG. 6 is a perspective view of a wood product made according to this invention. 1
DETAILED DESCRIPTION OF THE DISCLOSURE This process is useful with natural wood products as they are cut from the tree to proper or desired lengths. It may utilize pieces of wood which are debarked and either left whole or split or sawed according to the size and character of the wood product to be formed. One such size of a starter piece which has been found suitable is l X 1 inches and 16 inches long. However, larger pieces may be used as starter logs or for other purposes.
Natural wood products contain pores extending throughout the body thereof and which are initially filled with moisture and other gases and often waxes are absorbed in these pores. It is necessary to remove the moisture and other gases from within the wood products before the pores can be filled with a combustible liquid.
According to this process, the woodproducts are initially deposited in a receptacle, as indicated generally at l in FIG. 1, which contains a body of liquid petroleum 2, such as petrolatum or paraffin. Any suitable, readily combustible hydrocarbon may be used for this purpose, even the lower grades of paraffins or crude oil that will not vaporize at or below approximately C. A conventional burner is illustrated at 3 in FIG. 1 to heat the contents of the tank 1 to a cooking temperature of between C. and C. The temperature should be sufficient to volatize the moisture and gases within the wood products and will vary somewhat according to the size of the products. For example, wood products of the order of l X l X 16 inches or 2 X /2 X 16 inches may be cooked for a period of approximately 3 hours in the liquid bath 2, which will be sufficient to expel all of the moisture and gases from the pores of the wood products and to remove the encrusting substances therefrom which are partially changed in the process. This cooking action is for the purpose of degassing the wood products and does not of itself cause the paraffin or other petroleum product to be absorbed into the pores of the wood. This cooking is sufficient to remove all substances from the pores and to leave the pores substantially open throughout the body of the wood product.
After thus cooking the wood products in the paraffin or other petroleum product in the bath 2, the wood products are cooled either in the same bath or in another in the presence of the paraffin or other petroleum to a temperature of approximately between 70 C. and 75 C. which will have the effect of impregnating the paraffin throughout the pores of the wood products and throughout the depth of the latter.
I have shown in FIG. 1 a suitable container, generally indicated at 4, for containing the wood products immersed in the bath 2 and which may be lifted out of the bath if the products are to be transferred to a cooling bath 5 in a separate container 6. This may be accomplished by a suitable gantry crane or other device that will lift and transfer the receptacle 4 with the wood products contained therein. A heater 7 provides heat adequate to maintain the second bath 5 at the lower temperature of between 70 C. to 75 C., thereby to absorb the paraffin or other petroleum product.
This process produces an effective degassifying of the wood and a change in physical property of the wood fiber encrusting substances, including hemicellulose. The degassifying along with change in the hemicellulose binding property opens up cavities in the wood which are filled with the melted paraffin or other petroleum product. The change in physical properties are such that even the pressure of a fingernail along the grain can demonstrate the change in properties. Furthermore, these cavities so induced are permanent.
Either hard or soft wood may be treated in this manner, such as pine or oak. The wood products may be either debarked or sawed to proper size or split according to the uses to which they are to be applied.
An example of a split log is illustrated at 8 in FIG. 5, which is shown as partially broken away to illustrate the natural grain of the wood. This is suitable for many uses, including rail fences or as a starter log.
Another form of wood product is shown at 9 in FIG. 6. In this instance, the product is sawed and the natural graining effect is maintained either for combustion or for finish. The grain is changed, as described above, in the initial cooking.
Still another form of lighter log is illustrated in FIGS. 2 to 4. Here the wood product is indicated generally at 10 and is treated as described above so as to absorb the paraffin or other hydrocarbon throughout the pores of the wood. This wood product is wrapped individually in a suitable covering material, indicated generally at 11. It has been found to be practical to use a wax paper covering for this purpose which will properly enclose the entire area of the wood.
In using a wax paper covering, if this were ignited, it would burn off the wood without igniting the latter. However, it has been found that lighting strips, indicated generally at 12, can be applied to each opposite end portion of the wood product over the paper covering 11 and will be effective not only to ignite the paper covering, but to cause burning of the wood itself. Each of the lighter strips 12 is shown in FIG. 2 as secured along opposite edges of the wrapped wood product. The outer ends of these lighter strips 12 may be turned over and secured upon the ends of the wrapped wood product, as illustrated at the right in FIG. 2. Then these end portions may be peeled back, as shown at the left in FIG. 2, to cause ignition of the product.
Each' of the lighter strips 12 is preferably formed of a strip of paper, indicated at 13, with a backing of paraffin l4 and which serves to secure the paper strip 13 to the edge portion of the wrapped wood product. The paraffin layer 14 will be interposed between the paper strip 13 and the paper covering 11 in the relation shown in FIG. 2. The wrapped wood product provided with the lighter strips will make it possible to burn a single log and to ignite it by means of a single match which cannot ordinarily be accomplished with prior known processes.
This kindler log, as illustrated in FIGS. 2 and 3, may be used for igniting fire wood placed over the log or around it or for igniting charcoal in home grills. When made of paraffin, it is substantially nonvolatile, essentially odorless, and does not bleed and be absorbed by the paper container in which it is stored. Moreover, the log burns slowly, thus creating no danger to a person lighting it. Once it is ignited, it will continue to burn until the wood product is reduced to a minimum ash, whether using oak or pine wood. It is possible to burn in a fireplace even a single log made according to this 4 invention. The log is long burning and for an average size may require'as much as two hours for consumptron.
Wood products treated according to this invention may also be used for imparting desirable properties thereto for finishing, especially when these are used for corral fencing, truck bodies, implement handles, furniture and table tops, flooring and the like. The process will impart to the wood a high wax finish, especially when hard wood is treated in this way that will find many uses in service.
If it be desired to vary the natural wood finish, any suitable color or dye may be added to the paraffin bath and will be absorbed in the wood pores along with the thus colored paraffin.
While the invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein without departing from the invention set forth in the claims.
1. A process of treating wood to provide improved burning characteristics comprising immersing a natural wood product in a hydrocarbon bath, heating the bath to a temperature between about C. and C and sufficient to vaporize moisture from the wood and to form pores and passages therein, immediately thereafter cooling the wood product in the presence of hot hydrocarbon, which hydrocarbon provides improved combustion and burning characteristics to the wood, thereby absorbing the hydrocarbon in the pores and passages of the wood product and achieving substantially complete saturation thereof at ambient pressure, and wrapping the cooled wood product in a combustible covering material.
2. A process of treating wood according to claim 1, wherein the cooling of the wood product is in the same bath of hydrocarbon as that used for heating thereof.
3. A process of treating wood according to claim 1, wherein the cooling step is in a second bath.
4. A method of treating wood comprising immersing natural wood products in liquid paraffin, heating the paraffin to a temperature between 140 C. and 180 C. thereby removing substances from the pores and passages of the natural wood forming voids therein, and thereafter immersing the natural wood products in paraffin heated above the melting point of the paraffin and below approximately 75 C. causing the last-mentioned heated paraffin to enter the voids of the natural wood products.
5. A method of treating wood according to claim 4, wherein the paraffin fills the voids and becomes solidified therein.
6. A process of treating wood according to claim 1 wherein the said hot hydrocarbon further includes a color or dye.
7. A method of treating wood according to claim 4 wherein the said hot hydrocarbon further includes a color or dye.
8. A treated wood product of improved burning characteristics comprising a block of natural wood having a hydrocarbon filling the pores thereof, which hydrocarbon provides improved combustion and burning characteristics to the wood, a combustible wrapping extending around the block of wood throughout its length, and lighter strips effective to initiate burning of the wrapping and the wood adhesively secured to the outside opposite end portions of the wrapping, said lighter strips containing a hydrocarbon ignitible mate- 10. The treated wood product of improved burning characteristics of claim 8 wherein said lighter strips are secured along the ends of the wrapper whereby the end portions may be partially removed from the wrapped product to promote ignition of the wood product.