US 3091952 A
Description (OCR text may contain errors)
No Drawing. Filed June 30, 1960, Ser. No. 39,786 15 Claims. (Cl. 67-22) This invention relates to an improved candle formulation. It especially relates to a candle composed mainly of a combustible, porous core surrounded by a fusible, flammable solid having incorporated therein a minor amount of fine, combustible fibers; the candle having substantially non-drip characteristics.
The prior art of candle making has diligently been pursuing the art of making a candle with non-drip characteristics. In some cases, the candles have been prepared from wax formulations containing large amounts of high-boiling paraflin Wax. However, the burning characteristics of this type of candle are undesirable in that the flame dies down rapidly and insufi'icient paralfin melts to keep the flame alight.
In more recent times, non-drip candles have been prepared by using varying percentages of stearic acid in paraffin as the dipping progresses. For example, the initial clips are composed of wax containing 5-10% stearic acid. This composition is used until the candle is about /3 complete. The final dips are in a wax mixture containing 2030% stearic acid. During the burning process of this candle, the inner portion melts more rapidly than the outer rim, thus forming a cup that holds the liquid fuel until it is burned. The higher melting point Wax on the outer portion prevents the drip from pouring down the outside of the candle and marring the beauty of the candle.
While the above-mentioned multicomposition candles are generally satisfactory in non-dripping quality, there are attendant disadvantages to the process. The maintenance of wax mixtures of varying compositions is costly and inconvenient. In addition, there is considerable know-how or technique required in obtaining the proper thickness of the higher-boiling wax rim of the candle. If too much higher boiling wax is contained in the candle, the flame dies rapidly and is difiicult to re-light. If too little higher-boiling wax is concentrated along the periphery of the candle, the non-drip feature is not obtained.
The present invention provides a wax composition which, if prepared as a candle, overcomes the disadvantages of the prior art. A candle, prepared with the wax composition of the invention, Will be highly resistant to dripping under conditions of general use. In addition, candles prepared from the improved wax composition are relatively free from deformation or bending at moderately elevated temperatures.
According to the invention, an improved candle wax composition is prepared by incorporating in a wax a small amount of fine, combustible fibers having short fiber lengths. The invention is based upon the discovery that these fine fibers having hereinafter specified lengths, when incorporated into a wax candle, collect at the base of the burning Wick and form a Wax-saturated mat which prevents a pool of free-flowing wax from forming. Further, the wick is easily fed with fuel by the saturated mat. Thus, with the present invention, candles can be prepared from a single wax mixture and such candles will be substantially non-dripping and non-bending throughout general use.
The improved candles of the invention are formulated from wax which has mixed therein an appropriate small amount of fine fibers having the proper dimensions. These fiber dimensions are sufliciently small so that the 309L952 Patented June 4, 1863 2 presence of the fibers in the finished candle is practically unnoticeable. The small, fine fibers are usually the same color as the Wax but may, of course, be of a different color, if desired, for decorative purposes.
Any reasonably heat stable fibers can be used in practicing this invention. However, the fiber should be substantially insoluble in the wax and must be combustible. The material of the fiber need not be completely insoluble as long as the fibers of specified dimensions and amount remain particulate in the finished candle. The fiber material may be any natural or synthetic material which meets the herein described requirements. Examples of satisfactory fiber material to be used in a candle wax composition are: nylon, rayon, Orlon, cotton, silk, jute, and camel hair. Other equally satisfactory fiber materials are the fibers prepared from solid polyolefins such as linear polyethylene and crystalline polymers of propylene, butylenes, pentenes, hexenes, and the like. These polyolefins are especially advantageous in that they have densities close to the densities of petroleum waxes and hence have little tendency to settle out in the molten wax. The nylon, rayon, and polypropylene are the preferred fiber materials. The nylon fiber is especially preferred.
In the manufacture of non-dripping candles according to the invention, the above-described fibers with hereinafter specified dimensions can be incorporated in any fusible, flammable solid suitable for use in candles to produce artificial light through the burning of a combustible, porous core (i.e. Wick). The most common material used as the major component in candles are the Waxes. Specifically, various grades of petroleum waxes can be used and are preferred if the melting point of the wax is above F. Examples of petroleum waxes are the various grades of paratfin or distillate waxes. For example, suitable paraffin wax may have a melt point between 100 F. and 160 F., preferably between F. and F. (ASTM D87-42); a penetration at 77 F. of from 8 to 20 (ASTM Dl5653) and a Saybolt Viscosity at 210 F. of from 35 to 45 seconds. A typical petroleum parafiin Wax, as used herein for illustrative purposes, has a melt point of 132 F., a penetration at 77 F. of 13, and a Saybolt viscosity at 210 F. of 39. Other suitable hydrocarbon waxes include candellilla Wax, carnauba wax, montan wax, spermaceti and the like. Beeswax as used in candles for religious purposes is equally satisfactory.
The term wax as used herein includes the abovedescribed Waxes containing therein the proper amount of stearic acid plus the proper amount of additives such as anti-oxidants plus any other component normally used by those skilled in the art in formulating a candle wax composition for a particular use. The latter category includes such components as reodorants, dyes, and non- Wax-like materials which produce a particular burning effect, i.e., chemicals, etc. For example, the petroleum parafiin wax suitable for use in candles may contain from 5% to 30%, preferably 20%, stearic acid and from 0.001% to 0.002% di-tertiary-butyl-para-cresol as an oxidation inhibitor.
The Word candle as used herein is intended to include all objects which are capable of producing artificial light and which contain a combustible, porous core surrounded by any fusible flammable solid. Specifically the invention is applicable to those candles of the taper type which are usually used in a candelabra during banquet activities. Also, the invention produces an improved candle for decorative purposes, and is limited in shape only to the imagination of the manufacturer. In each case, the finished candle made according to the invention will have non-dripping and non-bending qualities.
The illuminating part of the candle is the combustible porous core commonly called a wick. The modern e3 candle wick is composed of strands of yarn in plaited form. A suitable wick material is selected cotton yarn which may be chemically treated to give better burning characteristics.
The actual preparation of the candle can be by any of the means known to the art. Such procedures include the older methods of dipping and pouring and the newer method of molding or casting. According to the invention, the improved candles are prepared by placing fibers of the proper dimension in molten wax using suitable agitation to insure proper mixing of the fibers therein, followed by molding the wax-fiber mixture around a wick in the desired form or shape.
The amount of fibers which should be employed varies with the diameter of a particular fiber used but generally should be less than 1% by Weight, for example, in the range of 0.005% to 0.5%. Unless the desired candle is of unusual size or shape, quantities of fibers less than 0.1%, usually in the range of 0.01% to 0.07% having a denier in the range of 1 to are preferred. It is particularly advantageous to use fibers having a denier in the range of 3 to 6. In some cases, the denier of the fiber may be as high as but the use of fibers of this diameter are restricted to highly specilized candles. Also a denier as low as 0.5 can be used if fiber strength is high. While the term denier normally applies to only synthetic fibers, it is intended herein to spply to both synthetic and natural fibers used for the present purpose.
The unexpected benefits of the present invention are dependent to a considerable extent on the length of the fibers used in admixture with the candle wax. It has been discovered that if the fibers are too short, no matting of the fibers will occur at the base of the burning wick and consequently the non-drip feature will not be obtained. For example, candles formulated with wax containing fibers of less than inch /2 millimeter) in length will drip to the extent of an ordinary non-fibrous wax candle. On the other hand, fibers which are too long will produce ends of fibers which stick up from the candle. These fiber ends become charred and destroy the pleasing appearance of the candle. In addition, fibers which are too long tend to agglomerate around the wick and cause the wick to burn unevenly with a flare-up effect.
According to the invention, fibers having a length of A; inch to 4 inch give excellent results. A general range of fiber length which should be satisfactory in most candles is from V to /2 inch, with the length of fiber selected in any given case largely dependent upon the particular fibers and amounts thereof used. It has been found, for example, that with nylon or rayon fibers a tendency for fiber ends to char and glow occurs when the fiber length exceeds 4 inch. Therefore it is desirable that the length of the fibers be less than /2 inch for inclusion in candle wax and it is distinctly preferable that the fiber length be between A; inch and inch.
The invention may be better understood by a study of the following illustrative examples. In each example, the wax composition was formed into a conventional candle about 14 inches long and about 1 inch in diameter with a slight taper, i.e., the top of the candle being of somewhat smaller diameter than the bottom. The data presented are the result of lighting the wick of the candle and observing its burning characteristics. The standard test consists of measuring the length of time required for the candle to develop a visual drip. By drip is meant the obvious formation of molten wax which flows over the periphery of the candle and which solidifies slowly as it falls down the side of the candle. The tests were conducted in an open room with minimum elfort made to avoid drafts.
Example I A petroleum paraffin wax having previously-mentioned properties and containing 20% stearic acid was used in preparing the following candle formulations. These re- 4. sults show the effect of using 3 denier nylon fibers, A: inch long.
Concentration of Nylon Fiber, Wt. Percent l The candle had burned down to about 2 inches in height.
2 Slight drip observed. The candles composed of wax containing from 0.01% to 0.07% fibers had excellent non-dripping qualities. The candles containing 0.1% and 0.2% nylon fibers developed a drip sooner than the blank composition containing no fibers, but the appearance of the fiame was excellent and a mat had formed around the base of the wick.
Example II The experiments of Example I were repeated except that polypropylene fibers were used instead of nylon fibers. The candle containing 0.1% fibers, inch long and 3 denier dripped slightly after 200 minutes. However, the candle containing 0.05% fibers of the same quality did not drip after burning for 570 minutes. These data indicate that a fiber concentration of less than 0.1% may be necessary before substantially nondripping properties are imparted to the candle; although in some cases, candles containing 0.1% to 0.2% fibers may have improved dripping characteristics.
Example III A candle was formulated from the wax of Example I and 0.2% of rayon fibers which were about 1 millimeter (0.039 inch) in length. This candle burned with a clear even flame and with no dripping for minutes. Visually, this candle was performing well. The dripping noticed after 180 minutes of burning was slight but again demonstrates that a concentration of from 0.1% to 0.2% fibers may be too high to impart the non-drip characteristic to the long, narrow tapered candle used hereinabove.
Thus, it is concluded from the above data that a candle composed mainly of a wick, petroleum wax, and less than 0.1% fine combustible fibers selected from the group consisting of nylon, rayon, and solid polyolefins having a fiber length of 0.039 inch to inch has substantially reduced dripping characteristics.
1. A candle having substantially non-drip characteristics composed mainly of a combustible porous core and a fusible, flammable solid having incorporated therein from 0.005% to 1% by weight fine, combustible fibers having a fiber length of inch to inch.
2. A candle having substantially non-drip characteristics comprising essentially a wick and wax having incorporated therein from 0.005% to 0.1% by weight fine, combustible fibers selected from the group consisting of nylon, rayon, and solid polyolefins having a fiber length of inch to inch.
3. A candle according to claim 2 are nylon.
4. A candle comprising essentially a wick, a major proportion of a wax selected from the group consisting of petroleum parafiin wax, beeswax, candellilla wax, rnontan wax, spermaceti wax, and carnauba wax; having incorporated therein 0.005% to 0.5% by weight fine, combustible fibers having a denier of 0.5 to 20 and a fiber length of 1 inch to inch.
5. A candle according to claim 4 wherein said wax is petroleum paraifin wax.
6. A candle according to claim 4 wherein said wax is spermaceti wax.
7. A candle according to claim 4 containing 0.01%
wherein said fibers to 0.07% fine, combustible fibers having a denier of 3 to 6 and a fiber length of inch to inch.
8. A candle according to claim containing 0.01% to 0.07% fine, combustible fibers having a denier of 3 to 6 and a fiber length of 4; inch to inch.
9. A candle according to claim 5 wherein said petroleum paratfin Wax has a melt point of from 120 F. to 160 F., a penetration at 77 F. of from 8 to 20, and a Saybolt viscosity at 210 F. of from 35 to 45 seconds.
10. A candle according to claim 8 wherein said petroleum paraifin wax has a melt point of from 120 F. to 160 F., a penetration at 77 F. of from 8 to 20, and a Saybolt viscosity at 210 F. of from 35 to 45 seconds.
11. A candle having substantially non-drip characteristics composed mainly of a wick and petroleum parafiin Wax having incorporated therein less than 0.1% by weight of fine, combustible fibers selected from the group consisting of nylon, rayon, and solid polyolefins, having a denier of 0.5 to 2-0 and a fiber length of inch to /2 inch.
12. A candle according to claim 11 wherein said fibers are nylon.
13. A candle according to claim 11 containing 0.01% to 0.07% of said fibers having a denier of 3 to 6 and a fiber length of inch to A inch.
14. A candle according to claim 13 wherein said fibers are nylon.
15. A candle according to claim 14 wherein said petroleum parafiin wax has a melt point of from 120 F. to 160 F., a penetration at 77 F. of from 8 to 20, and a Saybolt viscosity at 210 F. of from to seconds.
References Cited in the file of this patent UNITED STATES PATENTS 1,454,759 Nadler et a1. May 8, 1923 FOREIGN PATENTS 292,128 Germany May 26, 1916 23,286 Great Britain 1896