Title of Invention

A METHOD OF MANUFACTURING BAMBOO SPLINTS

Abstract

Disclosed herein is a method of manufacturing bamboo splints, which can be used as an alternate for matchwood. Said method comprising the steps of:- i) pretreating the bamboo with caustic soda solution or sodium meta- silicate and ammonia; ii) bleaching the pretreated bamboo by known methods, preferably with hypochloriate or peroxide; iii) carbonizing the bamboo splints using borates and phosphoric acid; and iv) wax fixing the splints of step 3, a treating the said splints with molten wax at a temperature of 80 to 120°C.

Full Text

This inventin relates to a process for development of match sticks from bamboo which can be used as an alternate for matchwood. It is known that matchwood which is used to prepare the splints for safety matches is selected from Poplar (Poplus species), Semuel (Bombax ciba). Rubber (Hevea brazilliesis). and Sawel. Field of Inventin: As stated hereinabove, the primary object of the present invention is the Sustainable Equitable Development of match splmts from bamboo, for replacing the matchwood that is currently being used. At present the match industry is facing problems such as shortage of matchwood and restrictions on imports. To overcome the above problems, replacements by fast growmg species such as bamboo has been tride to conserve wood used in the match industry. This would certainly conserve the forests and reduce the burden on imports. The economic method of treating bamboo splints involves procedures of, improving the colour of the splints for market acceptance, method to suppress post incandescence as a safety aspect and method of waxing to promote easy burning. It is also proved that reducing the thickness of the splints has not affected its strength properties. This research reports confines to Dentrocalumus strictius & Bambusa Bamboo, the bamboo species particularly found in South India, for the reason being most of the match industries are located in southern states such as Tamil Nadu, Kamataka, and Kerala. However, the same technology can be adopted with suitable modifications to the other species of bamboo found elsewhere, as well. Backgroounf of Invemtoin; Since }920's India is importing aspen logs for makmg match splints, as the required quantity of aspen wood is not available. After conducting several studies, aiternative species such as, Semuel, Sawal, Poplar and Rubber has been recognized as suitable for match industry. The match industries are presently using large quantities of semuel and poplar. In the recent years there has been a considerable depletion in internal supply of matchwood. In order to balance the expected shortfall in wood and help the existing match industries to continue to work, rather than reduce its capacity or shutdown due to shortage of raw material. Govt, of India is encouraging the use of any other woody species as an alternative for matchwood. Wax paper is also used as a substitute for wood in making the safety match splints. However, the after glow effect in the splints made of wax paper is high and therefore not advisable. As quoted in the very beginning, a Sustainable Equitable Development scheme has been taken up and utilization of bamboo in place of matchwood has been proved. This will help in conserving forests and thereby, contribute to our efforts for protection of environment Bamboo is a fast growing perennial grass, which matures for harvest in 2-4 years. It can be cultivated under social/farm forestry on homesteads also, in addition to its availability in forests in different climatic-zones. It is known that matchwood in the form splints undergoes a series of treatments such as bleaching, carbonization, waxing etc. before the final stage. BLEACHING It is reported in 1850's that "Wood and other objects get bleached after a long exposure to sun light". History reveals the fact THAT, bleaching of natural fibers containing proteinaceons materials, oils, waxes, dirt etc. can be done by the action of alkali solution, in order to reduce the time of bleaching. Milk of lime is the one that was used extensively in the beginning. Latter on use of sodium hydroxide, chlorine, sodium hypochlorite, calcium hypo chlorite and chlorine dioxide came to practice. Higher concentrations of these chemicals did not give satisfactory results. The method of bleaching incorporated here in the project works efficiently in bleaching 'bamboo splints' as well as in creating voids to fill the wax during wax fixation. CARBONIZATION Carbonization, in this context, is a process of treating the wooden splints in order to nullify the after glow effect, which is not desirable. Generally, the match splints are dipped in a bath of ammonium phosphate to eliminate the after glow effect. Although many chemicals are there for this treatment, much work has not been done with 'bamboo splints*. It is suggested for industrial safety reasons, such as handlings economy etc, that 'Boric acid' is the best chemical for treating bamboo splints to reduce the after glow effect. WO Publication No. WO/01/17929 describes a method of manufacturing matches and the like using bamboo as the support material which involves the treatment of the support material with suitable agents such as inorganic bases, for eg. NaOH, KOH or with a washing agent i.e. commercially available detergent, in order to alter the structure of the material to permit proper impregnation of the anti-giow treatment solution. The inorganic bases used are 10 to 30% (W/V) of base in water, at a temperature of 30 to 60' C for a period of 10 to 15 minutes. For impregnation with was including anti-glow treatment instead of bordes, this invention uses phosphoric acid, monoammonium phosphate, etc. Accordingly it is an object of the present invention to provide an inexpensive altemale to substitute match wood by bamboo, which comprises an optional pre-treatment of the bamboo with a bleaching agent at a pH range of 8.5 to 11 for a period of 12 to 16 hours at a temperature of 35 to 50°C and at a concentration of 3 to 10%, followed by carboniztion using borates at 70°C to 90T for 20 to 30 minutes and waxing using molten wax at a temperature of 80 to 120°C and contact time of 10 to 20 seconds. Summary of invention Experiments as per IS: 10374-1982 for the suitabiiity of match splints obtained from Dendrocaiamus and Bambusa have been evaluated for their quality, strength properties and commercial yields. The results are encouraging. Analomical features of bamboo favour in obtaining good strength splints even when the size with respect to cross sectional area is reduced to 75% of the existing ones. Use of Hypochlorite and peroxide bleaching at certain concentration, temperature and pH has given good results. In certain cases hot and cold treatments alter the degree of brightness of the splints. A Temperature of 45-60°C and at a pH between 8.0-12.0 improves the rate of reaction. Mode of pre-treatments, reflect on the pH conditioning chemicals consumption and effluent treatment. Another important feature of the present invention is - Carbonization, that plays important role in safety aspect of using match splints. In most of the existing match sticks this aspect is not practiced. An economic methodology involves, treatment with boric acid at concentration ranges of 0.2 to 10% and at a temperature of 55-85°C. However, borax or Phosphoric acid also can be used for Carbonization instead of boric acid. Burning character of the sticks depends upon wax fixation. This in turn depends on degree of wax penetraion. In ccase of bamboo, this would be achieved only by displacement of air by molten wax at 80-120**C. These experiments being successful in laboratory may need certain minor modifications in large-scale implementation. Detailed Description of the Present Inyention. Bleaching; The process in which natural colouring matter is removed from a fiber to make it white is called "Bleaching". Although oxidizing agents' effects most bleaching, an important class of agents bleaches by reduction action also. Prior to bleaching, a pretreatment step i.e. preliminary process is necessary. This preliminary step helps in uniform bleaching action. Generally bleaching reactions are not reversible. In those few instances in which colors can be restored, the action is probaly mild. Each class of bleaching agents have different properties; therefore a succession of bleaching treatments may be more effective than a single treatm ent. There are five categories of bleaching materials; 1 Chlorine; 2 Hypochlorite & chloramines; 3. Peroxides and other peroxy compounds; 4. Chlorite & chlorine dixoide; and 5. Reducing treats. Considering environmental factor, economy, safety in handling; and effluent treatment aspects, hydrogen peroxide and hypochlorite treatments have been found to be more suitable for bamboo splints. Effective bleaching of the present invention is based on controlled pH and synergistic property exhibited by hypochlorite and peroxide supported by sodium hydroxide and sodium silicate used in the pretreatment/pritiminary step. To achieve the full advantage of the present invention sodium hydroxide and sodium silicate must not be used in excess quantities. Use of these chemicals prior to hypochlorite / peroxide treatment assists in obtaining desirable brightness, without affecting strength and dimensional stability, when used in the match industry. Hydrogen peroxide (H3O3): Commercial hydrogen peroxide is of 30% concentration. It is too strong for many woods as it may make the wood brittle or affect its texture. So usually, it is diluted with water in the ratio 1:1 or 1:2. After dilution with water, ammonia with a specific gravity of 045. approximately 50-lOOcc is added Use of ammonia, m excess, may effect the reverse action, in woods containing tannins. Basically ammonia is used only to neutralize the acids that are formed during bleaching and help to maintain the pH of the bleaching solution. In certain cases, it has been found that, it is more advantageous to use only hydrogen peroxide. And once a required degree of bleaching is attained, the mi^eriai is washed with water. Sodium Hypochlorite : This is also one of the most powerful oxidizing agent. Strength of hypochlorite solution is usually measured in terms of "available chlorine". And the oxidizing power is expressed in terms of elemental chlorine. The rate of decomposition increases sharply with decrease in pH. And hence, it becomes utmost important to maintain the pH of the solution during bleaching, as acids liberated during bleaching tend to decrease the pH. Most suitable pH ranges for bamboo splints is range 9.0 to 11.0. Hypochlorite bleaching is generally done under cold conditions (at room temperature) for 12 to 24 hours. It was also seen that freshly fallen/cut bamboos are easier to bleach that that of dried ones. Keeping in view of cost and ease of operation, for industrial trails bamboo match splints were bleached with combination number 2 as given in Table 2, i.e. pretreatment with Sodium meta-silicate followed by treatment with Hydrogen peroxide. Test of strength on bleached bamboo splints revealed that there is no significant change in the strength and bleached match splints met the strength requirem ent as per IS 10374-1982. Carbonization; The method of carbonization treatn involves impregnation of a fire retardant compound that forms a non penetrable glass film that excludes oxygen and prevents further propagation or existence of post incandescence. Low melting inorganic borates and phosphoric acid in the concentration ranges of 0.5-8.0% at temperature 65-90°C produces desired level of after glow suppressant characteristics. The post incandescence measured in seconds and should not be greater than 3 seconds as per the specification IS: 2653-1993-Spec. for Safety Matches in Boxes. This carbonization is effected by dipping/soaking the splmts in hot solution for 20-45 minutes followed by dippmg/soaking in cold solution for 10-30 minutes or by cooling the hot solution to room temperature. Temperture maintenance on higher side would favour the impregnation there by reducing the time of hot treatment. However, the studies show with lesser time of hot treatment the effect is not up to the mark. Hence it is not advisable to reduce the dipping/soaking time less than 15 minutes. In accordance with an important feature of the invention, boric acid alone would exhibit the required degree of carbonization that can be accepted by match industry standards with respect to safety. Synergistic properties of boron compounds are utilized to effect carbonization. Boric acid in the range of 0.1 to 5.0% and/or Boric acid/borax mixture in the concentration range of 0.1-4.0% give positive response to the results. More encouraging results are obtained in the concentration ranging from 0.2-2.0% / 0.1-4.0% at temperature of 60-80'C. Phosphoric acid in the concentration, ranging from 0.5-3.0% at temperature of 60-80°C with soaking period of 10-25 minutes produces the same effect as that of boric acid. The time of soaking being most important determines the color of the bleached splints. The procedure of cold soaking or cooling hot sotation to room temperature is not followed because of the reason that long contact of splints with either concentrated or dilute phosphoric acid fades the color of the splints. A comparative study of general characteristics of Boric acid and phosphoric acid are given in Table-2 below that forms the basis for selection of the chemical for Carbonization. Treatment; Both manually made and machine made splints, which were bleached are treated in the Boric acid (0- 2.0%), Boric acid- Borax mixture (0-2.0%) and Phosphoric acid (0-1.0%). The results obtained are summarized in Table -3. Waxing of Match splints is one of the important steps from the point of view of uniform burning, which is a prerequisite for any matchstick. Normally, Match wood splints are dipped in molten wax and immediately head fixed and dried. In case of bamboo, wax does not penetrate easily and as a result burning becomes a problem. Hence several methods have been tried to improve the wax penetration. Viz. a. By increating the temperature of molten wax, preferably betwem 80- 12°C b. By increating the contact time with the molten,wax, preferably 10-20 second!. c. By pre-treatmet during bleaching which also helps in creating voids for wax. Voids created are observed through microscope. The above-mentioned methods are novel and they help to obtam good wax penetration and easy buring. The drawings accompanying the Provisional Specification illustrate the foHowing:- Figure 1 illustrates the Bar chart of Post incandescence of untreated bamboo Splints Vs cross-sectional area; Figure 2 illustrates Post incandescence curves of Bamboo splints treated with different concentrations of Boric acid and Borax mixture sohition; and Figure 3 illustrates Post incandescence curves of Bamboo splints treated with different concentrations of Boric acid and borax mixture sohition. HEAD FIXING A matchstick has an inflammable head that ignites only when struck on the friction surface. Composition of the head plays an essential role in making wooden splints is fired effectively when stroked against the friction surface of the matchbox. The temperature of the flame attained is also one of the major factors that determine the degree of flame transmission from head to the splint. After a series of analysis carried-out at the Institute laboratory, it is understood that varying percentages of Potassium Chlorate" in match head would give better result6s with respect to flam e transmission to the solints. However, two formulations presently used in Indian match industries are given in Table 4. Of these the second formulation, which is more widely used compared to the first, was used for "heads" for bamboo matchsticks. As facilities were not available in the institute laboratory, head fixing was done at a factory in Sivakasi. Testing for damp-proonfess Apart from the burning characteristics, adherence of the head to the match splint in different humidity conditions, is an important property that has a bearing with the material of the splint. Therefore, tests as per IS 2653-1993 were carried out by exposing the bamboo matchsticks at high humidity to see whether the head comes out. The test shall be carried out at a temperature of 27+2° C. the Matchsticks shall be conditioned at 27+2deg C and 65+5% relative humidity for six hours. Five numbers match box shall be placed in such a way that head side of each box is half open and each box is resting on its edge with the friction surface vertical as well as head up. One matchbox at a time is taken out and immediately each of the sticks is struck against the friction surface one by one for ignfting. The test shall be repeated with other boxes also. The numbers of matchsticks, which blink, fizz, does not ignite or whose head fly off, are recorded. Percent of damp proofness shall be calculated as follows: Damp-pro ofn ess (%) = (N-n)*100/N Where N='Total number of matchsticks taken for test, n-Total number of matchsticks which blink, fizz, do not ignite or whose head fly off. About 100 matchsticks were tested as per and it was found that none of the sticks blinked, fizzed, did not ignite or whose head flew off, indicating that head fixing was very good. Burning characteristics Bamboo match sticks after head fixing was subjected to burning test. It was found that the 'sticks caught fire in a single stroke plate 5 & 6 and the temperature goes up to 300°C which is comparable to the wood matchsticks available m the market. The burning was continuous and flame proceeded up to the end indicating that waxing of stick has taken place effectively. There was 'no after glow" and fire puts off quickly showing the effectiveness of carbonization. The novel feaures of the present invention can be characterized as follows: 1. Carefully controlled pH and temperature for bleaching should be in the range of 8.6- 11.0 and 30-50°C. The time required for bleaching is 12-16 hours. 2. The conditions stated in paragraph 1, holds good in pretreatment step using caustic soda solution of concentration ranging from 3 to 10% at temperature 35-50°C followed by the addition of 120 - 165 volumes of hydrogen peroxide, to carry out the bleaching. 3. In the pretreatment step, the caustic soda can be replaced by sodium-meta-silicate of 10-40% concentration with a suitable quantity of ammonia required to maintain the pH of 8-12. This is followed by the bleaching step. 4. Bleaching by hypochlorite/peroxide mixture in the ratio 1:7 to 2:5 gives the required degree of bleaching. 5. Strengths specified in paragraph 4 refer to Hypochlorite strength of 80-130 gpl of available chlorine and 65-130 volumes of peroxide. 6. The method of impregnation, which helps to avoid the after glow, consists of cooking the splints in a predetermined percentage composition of fire retardancy compound solution at 70°'-90°'C, where in fixation is favored by a soaking period of 20-30 minutes. An important point to be noted is that the concentration must not change with time. 7. In the step of paragrph 6, the predetermined percentage concentration can be varied depending upon time of soaking, batch size and temperature. 8. The waxing of bamboo splints can be improved of either by increasing the temperature of die molten wax or by increasing the contact time or by creating voids during bleaching process. We claim; 1. A method of manufacturing bunboo splints for use as match sticks comprising the steps of: a) optional pre treatment/bleaching of the bamboo splints using Sodium Metasiiicate of 10 to 40% concentration with a suitable quantity of ammonia required to maintain the pH of 8 to 12 or with Sodium Hydroxide solution at a temperature of 35-50°C followed by the addition of 120 - 165 volumes of Hydrogen peroxide; b) bleaching the pretreated bamboo splints under controlled pH and temperature in the range of 8,6 - 11.0 and 30°C-50°C for a period of 12 to 16 hours using hypochlorite/peroxide mixture in the ratio of 1:7 to 2:5; c) impregnating/carbonizing the bleached bamboo splints of step (b) which consists of cooking the splints in a predetermined percentage composition of a fire retardancy compound solution such as herein described at 70°C o 90°C for a period of 20 to 30 minutes; and d) wax fixation of the impregnated bamboo splints wherein the splints are dipped in molten wax at a temperature of 80-120°C for a contact time of 10 to 20 seconds. 2) A method as claimed in claim 1, wherein the strength of Hypochlorite is 80-130 gpl of available chlorine and 65-130 volumes of peroxide. 3) A method as claimed m claim 1 or claim 2, wherein the fire retardant compound is selected from inorganic borates and phosphoric acid in the concentration ranges of 0.5 to 8.0%. 4) A method as claimed in claim 3, wherein the borates are boric acid and/or boric acid/borax mixture. 5) A method as claimed in any one of claims 1 to 4, wherein the carbonization/impregnation is effected by dippmg/soaking the splints in hot solution for 20-45 minutes followed by dipping/soaking of die splints in cold solution for 10 to 30 minutes. 6) A method as claimed in claim 5, wherein the hot solution is cooled to room temperature to avoid the dipping of the splmts in cold solution. 7) A method of manufacturing bamboo splints for use as match sticks-substantiaily as herein before described and illustrated in the foregoing description.

Documents:

627-mas-2000-abstract.pdf

627-mas-2000-claims filed.pdf

627-mas-2000-claims granted.pdf

627-mas-2000-correspondnece-others.pdf

627-mas-2000-correspondnece-po.pdf

627-mas-2000-description(complete) filed.pdf

627-mas-2000-description(complete) granted.pdf

627-mas-2000-drawings.pdf

627-mas-2000-form 1.pdf

627-mas-2000-form 26.pdf

627-mas-2000-form 3.pdf

627-mas-2000-form 5.pdf

627-mas-2000-other documents.pdf