WO2016062839A1

WO2016062839A1 - A colored candle and a method for manufacturing thereof

Info

Publication number: WO2016062839A1
Application number: PCT/EP2015/074555
Authority: WO
Inventors: Jaroslaw Pawel Wolowiec; Krzysztof Tomanik; Andrzej Wrobel; Monika Zawadzka; Marcin Hurylski
Original assignee: Korona S.A.
Priority date: 2014-10-22
Filing date: 2015-10-22
Publication date: 2016-04-28
Also published as: EP3012317A1

Abstract

A method for manufacturing a colored candle, comprising the steps of: providing (11) a fragmented, non-opaque solid fuel; compression molding (12) the fragmented solid fuel to form a candle core;treating (13) the candle core with a liquid colorant solution comprising a solvent or a mixture of solvents based on organic volatile ingredients capable of dissolving fat compounds of the solid fuel in the amount of from 97 wt. % to 99,9 wt. % and a liquid colorant or a liquid colorant composition of a fat base in amount of from 0,1 wt. % to 3 wt. %, until the liquid colorant solution penetrates at least 50% of the candle core volume;and conditioning (16) the candle core until the colorant solution penetrates 100% of the candle core volume.

Description

A COLORED CANDLE AND A METHOD FOR MANUFACTURING THEREOF

TECHNICAL FIELD

The present invention relates to a colored candle and a method for manufacturing thereof.

BACKGROUND

Typical candles are formed of a solid body of a fuel source in which a wick is embedded. Fuel sources for candles, typically waxes, can cover a broad spectrum of products that include petroleum-, animal-, vegetable- and synthetic- based materials. Waxes refined from petroleum are used most commonly. However, other types of waxes have become popular in the last number of years - such as vegetable or plant based waxes such as palm stearin, hydrogenated vegetable oils and waxes from insects such as beeswax.

A typical process for manufacturing candles involves filling a mold, in which a wick has been positioned, with molten wax, allowing the wax to cool and then removing the formed candle from the mold. Another known technique involves compression molding, wherein the candle is made by using a powered wax or a mixture of powered waxes. The fine wax powder is compressed in a mold provided with a wick to make a candle.

The above-described manufacturing methods can involve producing colored candles or candles having the color of the natural wax. It is known to dye candles using two methods: by dyeing the wax before making the candle, so that a solid colored candle is produced; and by over-dipping plain white candles with layers of colored wax. To color the candle wax it is possible to use dyes or pigments or a combination thereof.

A US patent US1825785 discloses a method for manufacturing colored candles which involves coating a candle's white core with a permanent inner layer of a colored wax. This method involves mixing a powdered pigment with a molten wax mass, allowing the mass to set, re-melting the colored wax, adding stearic acid to the mass and over-dipping white candle cores with the mass. A US patent US7655054 discloses a method for producing colored glow through candles, wherein a candle core provided with a wick is over-dipped multiple times with a first liquid pigmented wax to form a first pigmented inner layer, followed by applying a second pigmented wax layer to three-quarters of the candle ball, a third pigmented wax layer to one-half of the candle ball, and a fourth pigmented wax layer to one-quarter of the candle ball.

Another method for preparing colored candles is known form a US patent application US20100132250. The method relates to manufacturing of compressed candles involving charging the mold with a prilled wax particles, in a single step, comprising hydrogenated natural oil and additives including coloring agents, compressing the prilled wax particles followed by thermally fusing an outer layer of the compressed prilled wax particles to form a thermally fused outer layer of the colored candle.

A US patent application US2012052455 describes a candle, in which coloring agents are limited to the outer peripheral surface of the candle and method of its production. The method involves dispensing, on an inner mold cavity surface, a wetting agent and dispensing into said cavity a coloring agent in a finely divided dry form and causing a portion of the coloring agent to adhere to the wetting agent, followed by dispensing a combustible candle composition into the mold cavity to form the colored candle.

A PCT patent application W09636685 describes a method for manufacturing colored paraffin and stearin in powder form, wherein a colorant is dissolved in a solvent before being added to the paraffin. It also relates to dipping (i.e. immersing just for a short time) of blocks of compressed paraffin and several other paraffin products (in the candle industry) in a solution containing a desired quantity of colorant. The dipping process is known in the candle industry as a process of immersing for the purpose of surface coating only, and not deep impregnation. Therefore, as a result of dipping, the colorant only coats the external surface of the block of compressed paraffin and does not penetrate inside the volume of the block.

The process of dyeing candles with over-dipping technique requires using large amounts of coloring additives released in molten wax. Moreover, candles manufactured this way usually lose their uniform color during burning process, as the outer colored layer tends to peel off or burn together with the candle core.

In turn, uniform color characteristic of candles obtained by dyeing the whole volume of the wax mass before preparing the candle core, requires production of large amounts of wax mass having a predetermined color. This necessitates fabrication of candles having the same color within the whole production batch. In consequence, changing the color of produced candles requires time-consuming cleaning of machines arranged in the production line, as well as storage of residual colored wax mass to be used, which may further lead to deterioration of wax quality.

Therefore, there exists a need for developing a method for manufacturing colored wax candles, in which the manufacturing process may be performed so that the candles color may be changed more easily within a production batch, without undue labor.

SUMMARY

There is dicsclosed a method for manufacturing a colored candle, comprising the steps of: providing a fragmented, non-opaque solid fuel; compression molding the fragmented solid fuel to form a candle core; treating the candle core with a liquid colorant solution comprising a solvent or a mixture of solvents based on organic volatile ingredients capable of dissolving fat compounds of the solid fuel in the amount of from 97 wt. % to 99,9 wt. % and a liquid colorant or a liquid colorant composition of a fat base in amount of from 0,1 wt. % to 3 wt. %, until the liquid colorant solution penetrates at least 50% of the candle core volume; and conditioning the candle core until the colorant solution penetrates 100% of the candle core volume.

The fragmented solid fuel can be compression molded to form a candle core having a density of 70% to 90% of the nominal density of the solid fuel.

The solid fuel can be translucent in a solid phase at a room temperature.

The solid fuel can be transparent in a solid phase at a room temperature. The candle core can be treated with the liquid colorant solution by immersing the candle core in a bath with the colorant solution.

The method may further comprise drying the candle core after being treated with the liquid colorant solution.

The method may further comprise coating the treated candle core with a molten, non-opaque solid fuel.

The molten, non-opaque solid fuel may have the same composition as the fragmented, non-opaque solid fuel.

The solvent can be selected from the group consisting of natural esters. There is also disclosed a colored candle manufactured according to the method as described above.

BRIEF DESCRIPTION OF DRAWINGS

The present invention is shown by means of an exemplary embodiment shown in a drawing, wherein:

Fig. 1 is a flow chart showing the process steps of the method of producing colored candles;

Figs. 2A, 2B show schematic cross-sectional views of a colored candle. DETAILED DESCRIPTION

There is disclosed herein a method for manufacturing a colored candle having a relatively homogenous colorant distribution in the candle core. The candle is formed by using a known compression molding technology. The presented method involves the use of raw materials (fuels) which are colorless, non-opaque, at least translucent, and preferably transparent in a solid phase at room temperature. For example, suitable raw materials are the known translucent, and preferably transparent, synthetic or natural waxes or mixtures thereof, such as, but not limited to: paraffin, palm stearin and fully hydrogenated palm oil and their compositions. The following are non-limiting examples of the raw material composition:

- 60 wt. % of palm stearin and 40 wt. % of paraffin

- 70 wt. % of palm stearin and 30 wt. % of fully hydrogenated palm oil - 100 wt. % of paraffin

- 60 wt. % of palm stearin and 20 wt. % of paraffin and 20 wt. % of animal fat

- 80 wt. % of palm stearin and 20 wt.% of animal fat

Optionally, the fuel composition may further include additives, such as fragrances.

Fig. 1 presents a flow-chart of the process for manufacturing colored candles. At the first stage 1 1 , solid waxes are grinded into smaller fragments and mixed uniformly using a known grinding technology. The fragments have a grain size from 0,05 mm to 15mm. In one example, the fragments may have a form of a powder, such as fragments having a size below 1 mm. In other embodiment, the fragments may be a mix of a powder and larger particles. In yet another embodiment, the fragments may be only larger particles, such as particles above 1 mm. In this stage, different additives, such as fragrances, can be added to the raw material. Then, the obtained fragments of fuel composition enters the compression molding station 12 wherein the fuel composition is compressed in the compression mold to form a colorless, non-opaque, translucent or preferably transparent candle core provided with a wick. The density of the candle core depends on the compression force applied at the mold. The candle core is preferably compressed to a density of 70% to 90% of the nominal density of the solid fuel (raw material) from which the fragments are made. During compression, the mold is preferably non-heated or heated up to the temperature not exceeding +60 °C in order to achieve the proper pore characteristic of the compression candle core, as well as its coherency.

In the following step, the candle core is supplied to a dyeing station 13 and treated with a colorant solution. Treating of the translucent or transparent candle core with the colorant may be accomplished by any suitable known technique, such as spraying or preferably immersing. The colorant solution comprises a solvent or a solvent composition based on organic (natural) volatile ingredients capable of dissolving fat compounds and a liquid hydrophobic colorant or liquid hydrophobic colorant mixture of fat base. The liquid colorants used may be either dyes or pigments or a mixture thereof. The weight ratio of the solvent component to the colorant component may vary from 97:3 to 99,9:0,1 . For example, the dyeing composition may comprise a solvent in amount of 99 wt. % and a colorant agent in amount of 1 wt. %, or the dyeing composition may comprise a solvent in amount of 98 wt. % and a colorant agent in amount of 2 wt. %. The percentage of the colorant affects the color intensity of produced candles. Preferably, the solvent is selected from the group consisting of natural esters, such as carboxylic acid esters (odorless), such as 2-methylglutaric acid dimethyl ester. Other suitable solvents are volatile ketones and aldehydes of hydrophobic properties.

The advantage of using organic (natural) ingredients is that they are well flammable, easily dissolve in fats and can easily penetrate the candle core.

During the dyeing, the colorant solution gradually penetrates the candle core and chemically reacts with the compressed fragments of the solid fuel from which the candle core is made, so that at least the outer surface of the compressed fragments is colored, but the colorant solution also penetrates into the compressed fragments. In other words, during dyeing, the candle core is impregnated with the colorant solution. The more intense the treatment, the deeper the colorant solution penetrates into the candle core to react with more and more fragments inside the core. Treatment intensity can be controlled for example by controlling the force of spraying, the amount of sprayed colorant, the time of immersion or the pressure during immersion. The treatment intensity is selected such as to allow the colorant solution to penetrate at least 50% of the candle core volume, i.e. that at least 50% of the compressed fragments are coated by the coating solution.

Preferably, the dyeing process 13 according to the invention is accomplished as follows. The transparent or translucent candle cores produced in step 12 are provided into a bath with the colorant solution under mild conditions. Preferably, the atmospheric pressure is maintained during all the dyeing process. Alternatively, increased pressure may be applied. The colorant solution temperature is maintained at the room level, e.g. about 20°C during the dyeing. The bath treatment is executed for a period that is necessary for the colorant solution to penetrate inside the candle core, which depends on the type of solid fuel and the colorant solution. Typically, this period is less than a minute, preferably 3 - 6 seconds. After the treatment time, the candle cores are removed from the bath. The treatment time affects the shade of color of the candle. When it is desired to produce candles of a lighter shade, the bathing time should be shorter. Extension of the bathing period is advised when candles of larger diameter are dyed.

After treating with the colorant solution, the candles are subject to a drying process 14. Herein, candles may be air-dried in an ambient temperature or the excess of the colorant solution may be removed from the outer surface of the candle by a compressed air stream. During the drying process 14, the colorant solution that was absorbed by the candle core during bathing 13, penetrates the candle core and is incorporated into the deeper core regions. The coherency and core density affect the depth of core penetration by the coloring agent.

Next, the candles are conditioned in step 16 in order to continue the penetration process. The penetration process may be continued even when the candles are assembled in end-user packaging and stored at the warehouse. During the storage, the penetration process continues to color the volume not colored during the dyeing. Preferably, the amount of colorant solution introduced during the dyeing process is such that during the conditioning phase the colorant solution penetrates 100% of the volume of the candle core. It was discovered that for the typical solid fuels as listed above and colorant solutions as defined above, impregnation of 50% of the candle core volume at the dyeing process is enough to achieve the effect of 100% impregnation after the conditioning process. The conditioning process typically takes a few days, or even 14 days.

The amount of the colorant solution used to color the candle core is dependent on the solid fuel and the colorant composition, but preferably the dried candle core may comprises from 1 % to 10% of the colorant solution, preferably about 5%. In an optional step 15, the candle may by optionally coated with a transparent or translucent coating material, for example the same material that was used for the candle core. Preferably, within the manufacturing line, a part of the mixture of raw material obtained at the grinding station 1 1 is added as a coating material at the station 15. The coating material (e.g. a wax composition) is melted, prior to being added, by using a suitable melting technique such as heating. The candle core, prior to being coated, may be put into a container made from a material sufficiently resistant for flame and heat released during burning of the candle, preferably translucent, or more preferably transparent, such as a glass jar. The coating process 15 is implemented by applying the melted wax composition onto the colored candle core, so that it creates an outer translucent or preferably transparent layer 24, as shown in Fig. 2B. The applied layer 24 is optional as it smoothes the candle surface. In order to make the candle with more porous surface, this coating step 15 can be omitted, as for the candle 20 shown in Fig. 2A.

Fig. 2A-2B shows exemplary cross-sectional views of the candle 20 manufactured according to the described method. The candle core 22 is provided with the wick 21 . The distribution of the coloring agent is schematically shown as dots 23. In the example shown, the colorant solution comprises about 5 wt. % of the colored candle, wherein the colorant agent is distributed substantially uniformly within the candle core of about 80% of the external candle core volume. Greater concentration of the colorant agent is distributed near to the core surface and decreases uniformly towards the core center. EXAMPLE EMBODIMENT OF A PROCESS

A raw material composition, comprising a mixture of natural and synthetic transparent waxes: 60 wt. % of palm stearin and 40 wt. % of paraffin, was grinded to a form of a fine powder. The powder was formed into the shape of a candle by compression molding. Next, the obtained core was introduced for 3 seconds into a bath with a colorant solution consisting of a solvent in the amount of 99 wt. % and of a liquid dye of fat base in the amount of 1 wt. % of the colorant solution, which resulted in that the colorant solution penetrated 50% of the candle core. Then, the candle core was naturally air-dried in the room temperature for 10 minutes. After absorption of the colorant solution (during the bath and air-drying) the colored core was put into a glass jar and coated with molten wax of the same composition as the candle core to form the outer candle layer. Next, the candle was conditioned for 2 weeks, and after that time the colorant solution diffused such that 100% of the candle core was colored.

The method described above enables making candles of different colors within one production batch without necessity of exchanging the whole batch of the raw material processed in the manufacturing line as well as time consuming cleaning the machines or expensive storing the residual wax mass. The candles obtained according to presented invention show substantially homogenous colorants distribution, and they do not lose their uniform color appearance during the burning process. By impregnating only 50% of the candle core during the dyeing phase, and allowing the colorant solution to penetrate the candle core later during the conditioning (storage) phase, the production efficiency (speed) is increased, economic efficiency is improved, as a relatively short time is spent on dyeing.

Claims

1 . A method for manufacturing a colored candle, comprising the steps of:

- providing (1 1 ) a fragmented, non-opaque solid fuel;

- compression molding (12) the fragmented solid fuel to form a candle core;

- treating (13) the candle core with a liquid colorant solution comprising a solvent or a mixture of solvents based on organic volatile ingredients capable of dissolving fat compounds of the solid fuel in the amount of from 97 wt. % to 99,9 wt. % and a liquid colorant or a liquid colorant composition of a fat base in amount of from 0,1 wt. % to 3 wt. %, until the liquid colorant solution penetrates at least 50% of the candle core volume;

- and conditioning (16) the candle core until the colorant solution penetrates 100% of the candle core volume.

2. The method according to claim 1 , wherein the fragmented solid fuel is compression molded (12) to form a candle core having a density of 70% to 90% of the nominal density of the solid fuel.

3. The method according to any of previous claims, wherein the solid fuel is translucent in a solid phase at a room temperature.

4. The method according to any of previous claims, wherein the solid fuel is transparent in a solid phase at a room temperature.

5. The method according to any of previous claims, wherein the candle core is treated (13) with the liquid colorant solution by immersing the candle core in a bath with the colorant solution.

6. The method according to any of previous claims, further comprising drying (14) the candle core after being treated with the liquid colorant solution.

7. The method according to any of previous claims, further comprising coating (15) the treated candle core with a molten, non-opaque solid fuel.

8. The method according to claim 7, wherein the molten, non-opaque solid fuel has the same composition as the fragmented, non-opaque solid fuel.

9. The method according to any of previous claims, wherein the solvent is selected from the group consisting of natural esters.

10. A colored candle manufactured according to the method of any of previous claims.