Note: Descriptions are shown in the official language in which they were submitted.
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002RIDGE-IN-GROOVE FIRELOG STARTER
004FIELD OF THE INVENTION
005This invention relates to composition firelogs and
006 m~ore particularly relates to a composition firelog including a
007 fire-starter means. The fire-starter means allows rapid, even
008 ignition of the composition firelog without using any
009 additional flammable materials.
010 Composition firelogs are well known and are commer-
011 cially available. The commercially available composition fire-
012 logs are of two general types. The first type consists of saw-
013 dust compressed with sufficient force to make the composition
014 log relatively dense and to cause the sawdust particles to
015 adhere to each other. The sawdust composition log may contain
016 a small amount of a binding agent to help maintain its
017 integrity. The other type of composition log is an intimate
018 mixture of wax and a cellulosic material. The cellulosic
019 material is generally a sawdust, but may be another material
020 such as waste paper, wood chips, or other types of cellulosic
021 particles. I
022 BACKGROUND OF THE INVENTION
023 A serious disadvantage of the composition firelog is
024 that it must be started by using accessory combustible
025 materials, materials which are inconvenient to use or generally
026 more flammable than the firelog itself. It would be advan-
027 tageous for the firelog user to be able to ignite the firelog
028 directly. U.S. Patent 1,310,004 describes a fuel stick made of
029 pressed material and having longitudinal grooves for retaining
030 wires. U.S. Patent 1,050,535 describes an artificial firelog
031 including petroleum and U.S. Patent 2,789,890 describes one
032 covered with an inflammable wrapper. U.S. Patent 3,726,652
033 describes a means of achieving ignition of a firelog by using a
034 solid fuel igniter.
035 SUMMARY OF THE INVENTION
036 In an artificial firelog consisting of an elongated
037 body comprising about 25-50 weight percent of a cellulosic
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002 material and 50-75 weight percent of a wax having a congealing
003 point or AMP of 50-95C, the improvement comprising at least
004 one longitudinal groove extending substantially along the outer
OOS surface of said body, said longitudinal groove having a longi-
006 tudinal ridge extending parallel to and within said groove.
007 BRIEF DESCRIPTION OF THE DRAWINGS
008 FIG. 1 is a perspective view of an artificial firelog
009 incorporating one embodiment of the fire-starting means of the
010 present invention.
011 FIG. 2 is a cross-sectional view of the artificial
012 firelog of FIG. 1.
013 ~ETAILED DESCRIPTION OF THE INVENTION
014 Applicants found that a wax/sawdust firelog can be
015 made easily ignitable by the inclusion of an elongitudinal
016 groove, slot or notch in its outer surface, if, and only if,
017 the longitudinal groove also contained a ridge, preferably a
018 thin ridge of dimensions appreciably narrower and of less
019 height than the groove. The discovery of this simple fire-
020 starter means is a substantial improvement over previous fire-
021 starter means which comprise contacting the firelog with more
022 combustible materials or filling a groove with more inflammable
023 materials than the artificial firelog composition.
024 In use, a match or ignition means is applied to the
025 ridge at one or both ends of the groove. The thin ridge is
026 easily heated and ignites more easily than the groove edges.
027 The ridge and its critical spatial relationship to the groove,
028 propagates the flame along the length of the log more quickly
029 than an ignited groove alone. No other ignition fuel is
030 needed, but an ignitable wrapper may also be included. In
031 positioning the log in the fireplace, the ridge-in-groove
032 indentation should be located on the substantially upper most
033 portion of the firelog. The firelog will contain at least one
034 ridge-in-groove, but may contain two or more ridge-in-groove
035 indentations in its outer surface. With two, three or more
036 ridge-in-groove indentations in the firelog, there will be
037 little need to rotate the log after placement in the fireplace
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002 in order to achieve easy ignition. When the ~aximum number of
003 ridge-in-groove indentations (about ten for a four-inch
004 diameter log) is utilized, the log will have the appearance of
005 alternating wide (about 1/2") and narrow (about 1/4") ridges
006 separated by about 1/4" wide grooves.
007 Time-lapse motion pictures directly comparing the
008 ignition characteristics of a plain groove vs. ridge-in-groove,
009 show the advantages for the ridge-in-groove include, more
010 reliable ignition, much faster flame propagation along the
011 length of the log, and shorter overall ignition time.
012 The cross-sectional shape of the ridge-in-groove has
013 not been found to be as important as the relative dimensions.
014 That is, the groove may be a slot or a notch having square,
015 round or V-shaped bottom portions. The ridge may be rounded,
016 rectangular or have an inverted V cross-section. Preferably,
017 the ridge is roughened by the natural adhesion of the composi-
018 tion to the die from which it is extruded ! to form a rough
019 ridge, as shown in FIG. 1, which is even more easily ignited.
020 Roughening of the ridge surface can be enhanced but the choice
021 of a forming die, for example the use of a die having a
022 slightly funnel shape will assist the formation of rough spots
023 on the ridge.
024 It is preferred that the groove have an overall
025 maximum width of from about 1/2 to about 1 inch and an overall
026 maximum depth of similar dimension. The ridge within the
027 groove must, of course, be of maximum width less than that of
028 the groove, and critically, will be of a width such that there
029 is at least 1/4~ of air space on either side of the ridge
030 between the outer surface of the ridge and the surface of the
031 groove. The height of the ridge is not critical, but will
032 normally be chosen to be less than the depth of the groove in
033 order to maintain the integrity of the ridge during wrapping,
034 shipping and storage of the artificial firelog.
035 While the artificial firelog containing at least one
035 ridge-in-groove is easily produced by extrusion of the firelog
037 in its usual production, the ridge-in-groove may also be formed
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0û2 later by the user of the firelog in the following manner.
003 During the manufacture of the firelog, two filamentary-means,
004 such as strings, wires, rods or other flexible elongated
005 bodies, will be embedded longitudinally at a depth of about
006 1/4-1 inch below the surface of said firelog and about 1/4-1/2
007 inch apart. Removal of said embedded filamentary-means prior
008 to ignition of the firelog will produce the ridge-in-groove
009 firelog of the present invention ready for ignition.
010 Preferably, the ridge-in-groove firelog of the present
011 invention is produced by longitudinally embedding two
012 filamentary-means about 1/2" below the surface of said firelog.
013 The composition artificial firelogs useful in this
014 invention comprise an intimate mixture of a cellulosic material
OlS and a wax. These firelogs are prepared by melting the wax and
016 combining the molten wax with the cellulosic material. The
017 intimately mixed mass of the wax and the cellulosic material is
018 allowed to cool and then placed in the feed to an extruding
01~ machine, generally a screw extruder. The mixture is extruded
020 as a continuous round or oval shaped rod of about 2 to 6 inches
021 in diameter, generally about 4" in diameter. The continuous
022 rod is then cut into lengths of from 6 to 18 inches, and
023 generally about 15" in length. The extruder would normally con-
024 tain a die which would form the ridge-in-groove indentation in
025 the rod as it is extruded. It is generally preferred that the
026 die have the approximate shape and dimension to produce a ridge-
027 in-groove of the aforementioned dimensions, and preferably,
028 that the die be tapered to produce the aforementioned roughness
029 in the ridge.
030 The cellulosic material useful in the composition
031 firelogs of this invention include practically any combustible
032 cellulosic material. Examples of suitable materials include
033 sawdust, paper, particularly paper waste, and, more particular-
034 ly, waste paper, fibers, particularly waste fibers, such as
035 cotton fibers, hemp fibers, waste vegetable matter, such as
036 coconut husk, straw, leaves, and the like.
037 A variety of waxes are suitable in preparing the
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002 composition log useful in this invention. Suitable waxes
003 include unrefined and refined waxes, with or without wax
004 additives. Suitable refined waxes include those having an AMP
005 (Average Melting Point) of about 50-95C, preferably of about
006 50-75C. These refined waxes generally contain in the neighbor-
007 hood of about 1% oil. Suitable unrefined waxes include slack
008 waxes which have an oil content of between 25 and 50 weight
009 percent, generally 40-50~ by weight. Because their high oil
010 content, slack waxes generally do not have a well-defined
011 melting point as determined by the AMP method. Suitable slack
012 waxes generally have a congealing point of between 50 and 95C.
013 Because of their lower cost, the slack waxes are generally pre-
014 ferred over the refined waxes.
015 Composition firelogs containing sawdust typically con-
016 tain between 50-60% by weight wax and 40-50~ by weight sawdust.
017 Composition firelogs made from waste paper typically contain
018 75-65~ by weight wax and 35-25% by weight of waste paper. The
019 composition of the log is adjusted to yield the lowest wax con-
020 tent consistent with good burning qualities.
021 Typically commercial firelogs are prepared from slack
022 waxes which have a high oil content. For this reason, they are
023 usually inserted into a paper bag, generally a polyethylene-
024 coated paper bag, to keep the oil of the slack wax from soaking
025 into objects with which the artificial firelog may come into
026 contact.
027 The firelogs including the ridge-in-groove firelog of
028 this invention can also be and desirably are, inserted into a
029 sack. However, the sack or wrapping, when it burns, typically
030 forms a certain amount of ash which can interfere with the even-
031 ness of the ignition obtained from the fire starting ridge-in-
032 groove of this invention. For this reason, it is preferred
033 that the sack containing the firelog be slit along the length
034 of the firelog adjacent to the ridge-in-groove. The slit sack
035 is then opened from the ridge-in-groove which may then be
036 easily ignited. The ash then formed when the sack burns does
037 not interfere with the flame propagation along the ridge-in-
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002 groove. Alternatively, and more preferably, the sack into
003 which the firelog is inserted has a "zipper strip" running the
004 length of the sack. The "zipper strip" is nothing but two
005 longitudinally oriented filamentary-means, such as strings,
006 which may also be imbedded in the log, as heretofore described,
007 to both open the wrapping and form the ridge-in-groove in one
008 step. The user places the firelog in the fireplace, preferably
009 on a grate, pulls the zipper strip which opens the sack from
010 end to end, and the resulting ridge-in-groove fire-starter is
011 then ignited. This causes rapid, even ignition of the firelog.
012 The paper wrapper generally catches fire and is rapidly
013 consumed.
014 The following example is included for further under-
015 standing of the invention.
016 The following are the results of a side-by-side
017 burning test comparing a plain groove log with ridge-in-groove
018 ~RIG) log. The test was recorded by a time-lapse movie camera.
021 TABLE
023 - Plain Groove RIG
024 Number of Ends Ignited 2 2
025 Tptal Top Ignition Time,
026 Minutes 20 5
029 In other single-log tests, the plain groove log has
030 required as long as one-half hour for the flame to spread
031 across the top of the log while the RIG log has consistently
032 done so in ten minutes or 1ess
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