DESC:Field of the invention
The present invention relates to a composition for combustible products comprising burn promoters such as polyethylene glycol (PEG) of having molecular weight ranging from 200 to 600, used in the concentration range of 5-10 wt% and dissolved in a volatile compound e.g. fragrance to achieve a sustained burn rate lasting for 30-45 minutes.

Background of the invention and prior art
Burning of agarbatti (incense sticks) forms an essential part of most religious ceremonies as part of offerings. It is generally considered a bad omen if a pooja agarbatti does not burn completely to its fullest length (a phenomenon referred to as “burnouts” in the industry). Various compositions of the incense sticks are available in the art.
847/MAS/1996 provides an agarbatti (incense stick) composition which comprises natural plant gums, semi synthetic gums and synthetic materials. A mixture of wood powder with charcoal powder when mixed with natural gums from plants or with synthetic and/or semi-synthetic materials, the resulting mixture provides required adhesivity and plastoelasticity. When these mixtures are used as dough to roll on the bamboo stick to prepare the incense sticks they achieve the desired properties. Further materials such as starch powder, calcium carbonate can be used to control the combustion. Natural gums according to the above invention may include guar gum, sodium alginate, isabgul, husk, okra. The semi-synthetic/synthetic materials may comprise hydroxyl alkylated/carboxymethylated guar gum, sodium carboxy methyl cellulose, poly acrylamide resins and salts of methyl/vinyl ether. Agarbatti of ‘847’may not ensure to eliminate or reduce the burnouts without affecting sustained burn rate and the sensory profile.
253/KOL/2003 provides an inflammable composition for igniting incense stick, wherein the composition containing glue formulation and casein formulation. The said glue formulation comprises potassium chlorate, glue, glass powder, sulphur, raisin, potassium bichromate, black powder and said casein formulation comprises potassium chlorate, casein, glass powder, potassium dichlorate, raisin, sulphur, zinc white, liquid ammonia. Further, according to ‘253’ there is also provided a process of manufacturing the inflammable formulation self igniting incense stick and an insect repellant stick comprising subjecting the stick to the step of dipping into an inflammable solution such that only the tip of the stick is coated with the said solution, and then drying the coated stick at room temperature. Said self igniting incense stick is silent to eliminate or reduce the burnouts without affecting sustained burn rate and the sensory profile.
390/KOL/2007 discloses a binder/adhesive composition comprising a mixture of jigat and at least one biopolymer selected from guar, maize, tamarind, ghatti, tragacanth, xanthan, pectin, Na-CMC, Na-alginate and gum karaya and the like. Further the various adhesives were screened based on GRAS (Generally Recognized as Safe) quality, availability and cold/hot set. The short listed adhesives belonged to exudates, extractives, natural and synthetic classes. The primary object was to find a suitable substitute for jigat or a suitable additive for jigat that would at least reduce the consumption of jigat in agarbattis. Masala ingredients typically consist of spent wood and white chips of sandal (kuppam dust), charcoal and binding material. To these three major ingredients, powdered pulverized aromatic herbs, roots, buds and bark are also added. The invention also relates to composition where jigat is completely substituted by a mixture of two or more biopolymers selected from guar, maize, acacia, tamarind gums and the like for use as binder in agarbattis. In order to make the experimental samples, various adhesives were added in place of jigat (complete substitution), whereas to make agarbatti with partial substitution, a mixture of jigat and adhesive in various ratios were added (partial substitution). The composition according to ‘390’ wherein the conventional jigat is either completely or partially substituted by mixtures of biopolymer results in burn time ranging from 35-45 min. However sustain burn rates as well as desired sensory profile might not been attained by using the process as disclosed in ‘390’.
1802/DEL/2011 provides an alternating binding material other than Jigat powder for making incense sticks. The raw materials used in ‘1802’ are abundantly available from forest/agricultural operations and effectively replace the Jigat in combination with gums and with or without common polymers (in lower ratio) which are readily available. The said binding material is composed mainly of gums of forest/plant/microbial origin especially gum Acacia, Dalbergia, Butea, Anogeissus, Sterculia, Kydia, Grewia, Guar, Tamarind, Agele, Xanthan, Sodium alginate, Carragenan, Agar, Maize and Carboxymethyl cellulose. Saw dust comprises sawdust of abundantly available trees such as Eucalyptus, Sal, Shisham, Teak, Bakain, Acacia, Pine, Poplar, Deodar, Neem, Casuarna, Alinathus, Hollock as well as that abundantly available as by-products of saw mills operating with other species. The composition of gums varies from 1-30% and that of sawdust from 10-50%, charcoal varies from 30-90% and 0.1 -10.0% of polymer comprising of polyvinyl alcohol, polyethylene glycol, polylactic acid, polycaprolactone, polyacrylamide and polyacrylic acid. Said polymer is gummy by nature. The agarbatti according to ‘1802’ can be prepared with or without jigat derived from Machilus macrantha or Litsea chinensis bark powder without affecting its binding and perfumery characteristics. The agarbatti prepared using said binding material is free from any kind of inflammable alkali metal salts. ‘1802 is related to an “improved binding materials for agarbattis”, which includes PEG as one of them. Further PEG in 1802 does not affect the perfumery or sensory profile of the incense stick.
US20120148636 relates to a method for making micro-particles containing actives and a composition comprising microparticles containing the said actives. This composition is well suited for use in various applications like personal care applications, laundry products and fragrance products. Encapsulation according to the invention of US‘636 provides protection of the active in the capsule matrix until the active material is intended to be delivered. The waxes that can be used in the above application is polyethylene glycol like wax of molecular weight 15000-25000, wherein the incorporation of wax or wax-like material provides the melting point to the composition in the range of 65oC to 100oC. Upon melting non-frangible type micro-particles of the composition releases the actives encapsulated within where in the active may be a perfume or a fragrance. One of the limitation of US‘636’ is the mentioning of the use of PEG have a molecular weight more preferable of 15000-25000 g/mole. The major disadvantages of this prior art is the use of higher molecular weight of PEG which cannot be dissolved in fragrance / water. Moreover it needs higher temperature for melting the same. This prior art is related to encapsulation technology and hence the objectives are very different.
WO02068005 provides a reaction mixture especially suited to generate heat in controlled manner. The said reaction mixture includes water soluble coating made of polyethylene glycol of molecular weight 2000-6000, volatile component, a buffer and anti-foaming agent. These said components encase the exothermic generating particles wherein the exothermic generating particles are consisting of uncomplexed metals, metal salts, metal oxides, metal hydroxides, metal hydrides. This composition is to provide the release of volatile components upon increasing the temperature of the reaction mixture to a set temperature. The volatile components are selected from a perfume, a fragrance, an insect repellant, a fumigant, a disinfectant etc. Further the above invention provides a continuous layer system that prevents the separation of water soluble coating and the exothermic particles when stored. This layer system allows quick start of the reaction after storage. These improvements are accomplished by increasing the molecular weight of the PEG used. Again, due to having higher molecular weight (greater than 600) said PEG is insoluble in volatile compound such as fragrance, perfume which therefore consequence improper mixing.
US20040000660 relates to a composition for aroma delivery with improved stability and reduced foaming. This disclosure states the use of PEG 4000-6000 as exothermic generating particles. However it has its own limitation for instance, the said burn modifier is not dissolved in fragrance due to its high molecular weight. Prior to use, it has to be melted using water and coated with additional exothermic particles such as magnesium powder. Further it has mentioned in the same application that PEG with a lower molecular weight e.g. 600 is not desirable since it is being liquid in nature and it delays the exothermic reaction.
Although several prior arts provide various incense stick compositions none of the prior arts address the problem associated with incomplete burning of the incense sticks which are considered to be a bad omen (inauspicious) during a Pooja. Few burn promoters are known in the art such as Tween 80, Span80 etc. However, they were found to interfere with the sensory profile of the combustible product. Thus there is a need to solve the problem existed in the prior art and to provide such incense sticks composition by a cost effective economical yet simple process which ensures to eliminate or reduce the burnouts without compromising on sustained burn rate and sensory profile.

Objects of invention
It is an objective of the present invention to overcome the drawback of the prior art.
It is another objective of the present invention to eliminate or reduce the burnouts in combustible product e.g. agarbatti / incense sticks.
It is yet another objective of the present invention to provide a combustible product with a desired sensory profile and/or enhanced sensory profile.
It is the further objective of the present invention to provide a composition comprising burn promoters such as polyethylene glycol (PEG).
It is an objective of the present invention to provide a composition wherein the said burn promoters PEG having a molecular weight ranging from 200 to 600.
Yet another objective of the present invention is to provide a combustible product with a desired sensory profile and/or enhanced sensory profile comprising PEG as burn promoter.

Brief Description of the Accompanying Drawing
Figure 1 illustrates the in-burn stage of the incense sticks made with and without the burn promoter in accordance with the present invention.

Summary of the invention
According to one aspect of the present invention there is provided a combustible product that eliminate or reduce the burnouts and enhance sensory profile comprising:
(i) a base formulation; and
(ii) an anti-burnout composition
wherein said anti-burnout composition comprising 5-10% by weight burn promoter such as PEG having molecular weight 200 to 600 and volatile compounds such as fragrance in an amount of 90-95% by weight;
and said base formulation comprising 30-60% by weight of charcoal, 30-50% by weight of saw dust and 10-30% by weight of gum or binder.

According to another aspect of the present invention, there is provided a method of preparing combustible product that eliminate or reduce the burnouts and enhance sensory profile of the present invention comprising;
(a) Preparation of an anti-burnout composition comprising the steps of:
(i) adding 5-10 wt% by weight of polyethylene glycol having molecular weight 200 to 600 in volatile compound at room temperature,
(ii) stirring the mixture as obtained in step (i) till polyethylene glycol dissolve completely;
(b) Preparation of a base formulation comprising the steps of:
(i) mixing 30-60% by weight of charcoal, 30-50% by weight of saw dust and 10-30% by weight of gum or binder to form an incense base,
(ii) rolling a bamboo stick into said incense base either manually or using a machine,
(iii) drying the mixture as obtained in step (i) under sunlight;
(c) incorporating the base formulation as obtained in step (b) into said anti-burnout composition (a) at the room temperature and allow settling down for atleast 12-24 hours.

Detailed description of the Invention
The present invention provides a combustible product comprising a base formulation and an anti-burnout composition that eliminate or reduce the burnouts and enhance sensory profile. Anti-burnout composition according to present invention comprises a burn promoter in an amount of 5-10 wt% and a volatile compound in an amount of 90-95 wt%.
According to the present invention the base formulation comprises, charcoal of 40 % by weight, saw dust of 30% by weight and gum or binder of about 30% by weight; said anti-burnout composition comprising burn promoter such as PEG of 5-10% by weight and a volatile compounds such as fragrance in an amount of 90-95% by weight.
The present inventors had aimed not only to eliminate or reduce the burn outs but also enhance the perfumery/sensorial effect of the agarbattis which is highly challenging and none of the prior arts have attempted the same so far. The present inventors have found that the molecular weight of PEG of 200-600 is highly desired and it must be dissolvable in fragrance / water. The present inventors have dissolved PEG 400 in fragrance and not to the agarbatti base composition.
Base formulation
The base formulation of the present invention comprises:
Charcoal : 30-60 wt%,
Saw dust : 30-50 wt%,
Gum or binder or adhesive : 10-30 wt%.
The gum or binder or adhesive according to present invention are selected from jigat, guar, maize, tamarind, ghatti, tragacanth, xanthan, pectin, sodiumcarboxymethyl cellulose, sodium alginate, gum karaya and like.
Anti-burnout composition
According to the present invention anti-burnout composition includes burn promoter at a concentration of 5-10 wt% and volatile compound.

Burn promoters
The burn promoters should have the properties such as they should be rich in oxygen content, should have a capacity to release oxygen slowly to support continuous burning of the incense stick from start to end and that should not affect the sensory performance of the fragrance.
According to the present invention polyethylene glycol (PEG) having a molecular weight ranging from 200 to 600 (PEG 200-PEG 600) can be used preferably as burn promoter in anti-burnout composition.
According to the preferred embodiment the molecular weight of polyethylene glycol (PEG) is 400.
Volatile compounds
According to the present invention volatile compound as used in anti-burnout composition can be fragrance, perfumes etc which may be selected from any perfume or fragrance to be used in agarbattis/incense sticks; importantly those are dissolvable in PEG molecular weight 200-600, e.g. sandal, jasmine, rose, fragrance. This includes commercially available perfume and fragrances which are commonly used in agarbattis such as Mahadivya, Aatmika, Northern Rose, Bouquet, Dwaitham, Wind Fusion, Adore Madhurai Pooh, Shreyen, Adwaita and the like.
According to the present invention volatile compound at a concentration of 90-95 wt% is used in anti-burnout composition.
In another embodiment the present invention provides a process for making the combustible product such as incense sticks comprising:
(a) Process of making anti-burnout composition comprising the steps of (i) mixing the required amount of PEG (200-600), preferably, 400 with the volatile compound such as fragrance at quantity sufficient at room temperature (RT); (ii) stirring the mixture until the PEG is completely dissolved.
(b) incense base is prepared by mixing charcoal, saw dust and gum or binder to form an incense base
(c) Base composition can be conventionally prepared comprising the steps of (i) rolling the bamboo stick into incense base either manually or using a machine; (ii) drying the mixture under sunlight.
(d) The sticks with the dried up incense base is incorporated into said anti-burnout composition at RT and allowed to settle down for atleast 12-24 hours to obtain the desired or enhanced sensory profile and sustained burn rate.
Accordingly to the present invention there are two components in the present invention, (1) base formulation and (2) anti burn out formulation. Firstly, using the base formulation as prescribed in the below table, the battis are made. Secondly, those battis are dipped in the anti-burnout formulation as given below.
(i) Base formulation Wt% (in range) Wt% exact
Charcoal 30-60 40
Saw dust 30-50 30
Gum/binder Oct-30 30
(ii) Anti burnout formulation Ingredients E.g. 1 E.g. 2 Claiming range wt%
PEG 5 10 5-10%
Fragrance 95 90 90-95%

The final product can be stored or remain sealed (packed conditions) for longer duration which still provides the desired results.
The combustible product as described herein may be selected from but not limited to agarbattis/incense sticks, batti, dhoop, Joss sticks, insect repellant stick or coil.
The following features are intended to describe the expression used in context of the present invention.
"Neat" as herein referred to as incense stick is still not lit.
"In Burn" refers to incense stick which is burning.
"Post Burn" means when incense sticks are burnt completely.
“Burn out” as herein referred to as agarbatti/incense stick extinguishes in between instead of burning completely.
The present invention is now being illustrated by way of non-limiting illustrative examples.

Example 1
Incense stick composition
Table 1: Anti-burnout composition of combustible product e.g. incense stick
Ingredients Concentration wt%
PEG 400 5
Fragrance 95

Table 2: Base formulation of combustible product e.g. incense stick
Incense stick base formulation Concentration wt%
Charcoal 40
Saw dust 30
Gum / binder (e.g. jigat, guar, maize, tamarind, ghatti, tragacanth, xanthan, pectin, Na CMC, Na alginate and gum karaya and the like) 30
Bamboo sticks

Process for making the anti-burnout combustible product such as incense stick
i. Preparation of anti-burnout composition
PEG 400 is added at 5 wt% to the volatile compound such as fragrance, perfume (qs) and mixed by stirring at RT till PEG 400 is dissolved completely.
ii. Preparation of incense stick
The bamboo-sticks are rolled into the incense stick base/masala, which are prepared by any conventional method, either manually or using a machine and dried under sunlight. Once dried, the sticks are dipped into the anti-burnout composition at the RT and allowed to settle down for atleast 12-24 hours to obtain the desired or enhanced sensory profile and sustained burn rate. The final product can be stored after sealing.
These incense sticks were compared with sticks prepared without the anti-burnout composition to evaluate the burn characteristics
Result:
The present invention contemplates zero or reduced burn outs of the incense sticks. When the control sample (composition which does not contain anti-burn composition) and incense stick treated with anti burn out composition, the control samples burn only for about 20-25 minutes, leaving 40-50% of agarbatti unburnt, while, the treated incense sticks, burnt completely.
As evident from Figure 1, the incense stick on the left has extinguished midway during the process of burning which was prepared without the anti-burn composition while the right hand stick is still in the in-burn stage.

Example 2
Determining the Burn-out % and Sensory Profile of the anti-burnout compositions
i. Burn out % determination

ii. Sensory profile determination
Stage Wise Performance of an agarbatti sample is calculated by averaging the parameter scores under each stage as follows.
· In-Burn Stage Performance = average (AVG) of ratings# of Profile likeability (Note*) and Diffusion.
· Neat Stage Performance = AVG of ratings# of Profile likeability (Note*) and Strength.
· Post-burn Stage Performance = AVG of ratings# of Profile likeability (Note*) and Diffusion

Further determination of the sensory profile is dependent on following parameters:
Sensory Overall Performance is calculated based on AVG (a, b)
a. Likeability Performance = AVG of ratings of the Profile likeability (Note*) in the neat, in-burn and post-burn stages.
b. Impact Performance = AVG of ratings of the Strength of neat stage, Diffusion of the in-burn stage and Retentivity of the post-burn stage

*Parameter Definitions
· Note - A distinctive odor, which can be recognized or identified (e.g. Rose, Sandal, Minty)
· Profile Likeability - The extent to which one likes the odour
· Strength - Intensity of the odour
· Impact - The sudden, sharp, but very short-lived sensation, which is noticed immediately at the first sniff
· Diffusion - Even distribution of the fragrances within the available space.
· Retentivity - Lingering of fragrance in the evaluation room

# Rating the note / Profile, Impact / Diffusion, Retentivity is on a scale of 1 – 5.
5 – Too strong; 4 – Strong; 3 – Average (desired); 2 – Weak ; 1 – Very faint.

Comparison of Burn-out% and sensory profile of the compositions containing various anti-burnout promoters
The burn out% and sensory profile were determined in absence and presence of various burn promoters using the method as described in example 1. The various burn promoters used in the present invention are Tween 80, PEG 400 and Span 80. The results are shown in table 3.

Table 3: Burn out% and sensory profile of the compositions containing various anti-burn out promoters
CONTROL-Incense sticks Burn out % Sensory Over All Performance(Average of likability & impact performance)
Lot 1 Lot 2 Lot 3
Fragrance 100% 5 1.7 1.3 3.1
SPAN80 5% + Fragrance QS (sufficient quantity) 0.0 NTC* NTC* 2.9
Tween 80 5%+ Fragrance QS 0.0 0.3 1.0 3.3
PEG 400 2% + Fragrance QS 8.8 NTC* NTC* 3.6
PEG 400 5% + Fragrance QS 0.3 0.3 0.3 3.6
Note: Lot 1, Lot 2, and Lot 3 comprise at least 200 incense sticks in each lot. When the anti-burnout composition was not used, the burnout % variation was high. Span80 although has given reduced burn outs but did not give desired sensory profile and hence no further tests have been made; *NTC: No Tests Conducted.

Result:
The data show that SPAN80 at 5 wt% concentration results in zero burnout in Lot 1 but at the same time it does not yield the "desired sensory profile" which is below the desired level of 3%. Tween80 at 5% though results in desired sensory profile, however lot to lot variations are observed with respect to % burn out.
PEG 400 at 2% results in high burnout while at 5% concentration desired results are obtained such as reduced and uniform burnout and "desired sensory profile".

Example 3
Test for efficacy of PEG 400 in reducing burnouts in agarbattis when added to agarbatti base/masala composition

PEG 400 added on to Agarbatti base composition (negative example)
· 50gms of PEG 400 (5%) was added to 1000gms of agarbatti base composition (dry premix)
· The premix was homogenised in a mixer for half-an-hour
· Dough was made from this premix and battis rolled out
· The dried raw agarbattis were fragranced with fragrance (containing no PEG 400) & tested for burnouts. Results showed high variability i.e. 0.4 to 0.8% burnouts. The observed variability is mainly due to non-homogeneity of PEG 400 added directly on to the agarbatti base.
· However when the readily made agarbattis are dipped in the fragrance containing PEG 400, showed greater consistency in terms of reduced burn outs.
· Hence it was concluded that presence of PEG 400 in the anti-burn out composition along with the fragrance is more effective in reducing burnouts than the said PEG 400 being present in the base composition.

Results are given in the table 4 below:
Table 4
Example Burnouts (%) – Lot 1 (200 sticks) Burnouts (%) – Lot 2 (200 sticks) Burnouts (%) – Lot 3 (200 sticks)
PEG 400 added onto the agarbatti base: (negative example)Agarbattis made with Dry premix(base composition + PEG 400 @ 5% dosage) + Fragrance (e.g. Mahadivya) Inference: Shows high variability 0.4 0.8 0.7
PEG 400 added to fragrance in anti-burnout composition: (positive example)Agarbattis made with Dry premix (base composition) + anti-burnout composition (comprising fragrance + PEG 400 @ 5% dosage)Inference: Greater consistency in all the lots. 0.3 0.3 0.3
,CLAIMS:1. A combustible product that eliminate or reduce the burnouts and enhance sensory profile comprising;
(i) a base formulation; and
(ii) an anti-burnout composition
wherein
said anti-burnout composition comprises 5-10% by weight burn promoter such as PEG having molecular weight 200 to 600 and a volatile compounds such as fragrance in an amount of 90-95% by weight;
and
said base formulation comprises 30-60% by weight of charcoal, 30-50% by weight of saw dust and 10-30% by weight of gum or binder.

2. The combustible product as claimed in claim 1, wherein said polyethylene glycol has a molecular weight preferably 400.

3. The combustible product as claimed in claim 1, wherein said volatile compound is fragrance or perfume.

4. The combustible product as claimed in claim 1, wherein said gum or binder or adhesive is selected from jigat, guar, maize, tamarind, ghatti, tragacanth, xanthan, pectin, sodium carboxymethylcellulose, sodium alginate and gum karaya.

5. The combustible product as claimed in any preceding claim is an incense stick, batti, dhoop, joss stick, insect repellent stick or coil.

6. The combustible product as claimed in any preceding claim preferably is an incense stick.

7. A method of preparing a combustible product that eliminate or reduce the burnouts and enhance sensory profile as claimed in any of claims 1-6 comprising :
(a) Preparation of an anti-burnout composition comprising the steps of:
(i) adding 5-10 wt% by weight of polyethylene glycol having molecular weight 200 to 600 in volatile compound at room temperature,
(ii) stirring the mixture as obtained in step (i) till polyethylene glycol dissolve completely;
(b) Preparation of a base formulation comprising the steps of:
(i) mixing charcoal, saw dust and gum or binder to form an incense base,
(ii) rolling a bamboo stick into said incense base either manually or using a machine,
(iii) drying the mixture as obtained in step (i) under sunlight;
(c) incorporating the base formulation as obtained in step (b) into said anti-burnout composition (a) at the room temperature and allow settling down for atleast 12-24 hours.

8. The process as claimed in claim 7, wherein said polyethylene glycol is preferably polyethylene glycol 400.

9. The process as claimed in claim 7, wherein said volatile compound is fragrance or perfume.

10. The process as claimed in claim 7, wherein said base formulation comprises charcoal in an amount of 30-60% by weight; saw dust in an amount of 30-50% by weight; gum or binder or adhesive in an amount of 10-30% by weight and a bamboo stick.

11. The process as claimed in claim 10, wherein said gum or binder or adhesive is selected from jigat, guar, maize, tamarind, ghatti, tragacanth, xanthan, pectin, sodium carboxymethylcellulose, sodium alginate and gum karaya.

12. The process as claimed in any preceding claim for preparation of an incense stick, batti, dhoop, joss stick, insect repellent stick or coil.