US2495575A - Methods and materials for stiffening paper match splints - Google Patents

Description

Patented Jan. 24, 195

METHODS AND MATERIALS FOR STIFFEN- ING PAPER MATCH SPLINTS Herbert Ellern, St. Louis, Mo., assignor to Universal Match Corporation, St. Louis, Mo., a corporation of Delaware No Drawing. Application March 7, 1947, Serial No. 733,190

1 Claim.

This invention relates in general to certain new and useful improvements in methods and materials for stiffening paper match splints and, more particularly, to methods and agents for impregnating formed paper match splints for increasing the strength and general utility thereof.

In the manufacture of book-matches, a web of a certain type of cardboard is transformed in a punch-press, or by other means, into so-called strips or combs consisting of a solid strip of cardboard e. g. 12 inches Wide and inch from which extend normally 100 sticks or splints, each commonly 1% inches long and /8 inch wide. The caliper or thickness of the matchboard is usually around 0.040 inch, the apparent density of the board is close to 0.70. In the further process of book-match making, the tips of the splints are immersed to a small fraction of an inch into molten paraffin, whereby a small part (usually to inch) of the splint is impregnated with paraihn, for the purpose of later enabling the ignited pyrotechnic mixture forming the head to transfer its flame to the stick which otherwise would not catch fire.

For purposes of economy, the paraffin used for this impregnation is mostly a crude yellow or white parafi'in of high oil content and low melting point and, therefore, fairly soft at room temperature. Better grades of parafiin are used occasionally in smaller factories, but, in any case, the sole purpose of the impregnation has always been the need for easy transfer of flame to the stick and not a modification of the physical properties of the splint. In fact, whenever, by accident, the impregnation exceeds the usual length of imbibition, e. g. during a stop in operation, such match splints are regarded as waste and are destroyed.

It is well known that the book-match splint is much inferior in strength to the wooden match. Notwithstanding its width of 0.125 inch, it is necessary to grasp the splint fairly close to the head and withdraw the fingers immediately after the lighting has taken place, and when the paper match is drawn across the striking strip with the wider edge of the head and stick facing and pressed against the striking surface, danger of breakage is even greater. While individual habits vary widely as to the pressure applied and positions of the match in the act of striking, it frequently happens that the paper match splint, after the act of striking, is deformed, partly broken through, and occasionally broken into two pieces. This flimsiness of the book-match causes many people to avoid their use since they are afraid of getting burned in the act of striking, due to the proximity of the fingers to the point of ignition, and they are unwilling, or unable, to submit to a routine of quickly shifting the fingers, a form of dexterity which is not needed in the'use of the highly rigid wooden match.

On the other hand, there is an increasing scarcity of wood suitable for wood-match making, as well as an enormous waste in such woods because of the need of producing flawless wood blocks free from knots and crooked fibers. Furthermore, the need for shipping Wood-blocks from remote wooded regions to the centers of match manufacture creates a substantial freight problem. In addition, match-splint cutting operations not only require the use of very small wood-blocks which must be hand-fed into the machine, but also require experienced operators, because the blocks must be fed only in a certain direction in reference to the direction of the grain, to avoid oblique splitting of the splints.

It is, therefore, the primary object of the present invention to provide methods and materials for making an improved paper match-splint of such rigidity and breaking strength that it approaches the strength of a wooden splint of equal dimensions.

It is also an object of the present invention to provide impregnants for treatment of matchboard which are inexpensive, low-melting, which burn freely without producing soot or noxious fumes, and which are low in viscosity at the temperature range in which treatment is carried out.

It is, furthermore, an object of the present invention to create a paper match-splint of reatly reduced width, increasing the number of lights per book for the same area of frontage, While still maintaining a strength superior to the regular paper splint, thus not only saving paper board, but also reducing the amount of head composition clue to the smaller cross-section of the tip.

It is also an object of this invention to provide a book-match of greatly reduced width, but increased thickness or caliper, approaching more or less a square cross-section, thus creating a book-match which, no matter which point of the surface of the head is pressed against the striking surface, will have higher rigidity and breaking strength superior to the conventional bookmatch, and which, aside of other advantages, e. g. reduction in dimensions of splint area and cover area, also take a much smaller head than an ordinary book-match.

It is, furthermore, an object of the present invention to adapt the methods and materials of the present invention to conventional methods of book-match splint production, for the manu-- facture of an improved match splint, such as a splint of approximately square cross-section.

t is another object of the present invention to eliminate and replace the customary paraffining of the splint without requiring elaborate, costly, or space-consuming changes or additional equipment.

With the above and other objects in view, my invention resides in the novel processes and compositions of matter presently described and pointed out in the claim.

Broadly speaking, my invention comprises the treatment of match-board, during the course of its progress through the match-making process, with a relatively inexpensive, low-melting impregnant, which burns freely without objectionable smell or soot, and which is low in viscosity in the temperature range in which treatment is carried out. It is also possible to employ combinations of impregnating substances with or without admixture of resinous substances and other modifying agents which, at a suitable temperature, form a homogeneous or practically homogeneous melt, are easily and quickly imbibed into the immersed cut splint, filling the interstices between, and binding together, the fibers of the match-board splint, and which congeal rapidly at room temperature to produce a marked increase in stiffness and breaking strength of the resulting match-splint, and at the same time replace the conventional parafiining of the splint for the purpose of transferring the flame of the burning tip composition to the stick. A preferable form of impregnant may comprise a medium to high melting point parafiln wax combined with a small quantity of opal wax and carnauba wax, and the latter waxes may be supplanted partly or totally by waxy substances of the class of microcrystalline Waxes of the hard or brittle type, stearic acid, ozocerite, montan and ceresin wax.

It is also possible to use an impregnant including resinous substances especially rosin itself, or in modified form, e. g. as salt, ester gum, or modified ester gum. It has been found that especially the products commercially known as limed resins, when incorporated with paraifin wax, provide excellent impregnants which form clear thin homogeneous melts at practical temperatures in various proportions, though I practically limit the addition to about 20% since, with increased amounts of rosins beyond this point, the combustion of the compound becomes more and more sooty and, also, no appreciable gain in strength is achieved beyond this amount. I do not limit myself, however, to this particular type of modified rosin, having found that plain rosin, hydrogenated rosin, especially after liming, and other salts beside the calcium resinate, especially zinc resinate and also lithium resinate, as well as ester gum and modified ester gums, can be incorporated in parafiin or wax combination melts with varying ease and in varying amounts, though sometimes requiring the addition of a compatibility-promoting substance. I have found that the breaking strength of an ordinary match stick determined at 150 grams plain can be increased up to 450 grams'with the addition of rosin derivatives, which latter figure approaches closely the calculated strength of a wooden splint of the same dimensions.

It is also possible to incorporate into paraffin wax varying amounts of materials of the class of the cumar-resins, fused copal gum, and ethylcellulose mostly using third substances to promote compatibility and other suitable properties. It has also been found that hard varieties of gilsonite in quantity up to 20% can be incorporated into paraffin wax melts and not only greatly improve the strength of the splint, but also cause a jet-black coloration, which heretofore could only be achieved at a considerable added expense.

I have also incorporated into paraffin-gilsonite combinations an appreciable amount of sulphur with further improvement of the strength and while the smell of burning sulphur in matches is nowadays regarded as objectionable, in this country, I claim the incorporation of sulphur as an addition to my melt since it is efficient, low in price, and tolerated by people on a lower economic level.

It is also possible to incorporate into the melt such other substances which will promote compatibility, modify the viscosity of the melt, or melting point of the compound, or both, produce a distinctive color of the stick, impart fragrance to the match, or to the gases of combustion, or both, and improve or retard speed of combustion of the burning wax or act as a glow preventative for the burnt out fiber mass, as for example, small amounts of high-boiling solvents, oil-soluble salts of fatty acids and high melting point synthetic waxes for modification of the physical properties especially viscosity of the melt itself oil-soluble or wax-soluble dye-stuffs and oil dispersible pigments especially the dye base fatty acid compounds for colorings; perfume oils or other fragrancy imparting substances; and derivatives of the class of organic compounds of phosphorous and boron, as well as other compounds of the class of phosphor or boron-acids, which are soluble in the wax melt or finely dispersible in it as flame-retarding and/or glowpreventing compounds.

By way of illustration, and not by way of limitation, it has been found that the following specific formulae will produce excellent results:

Example I Parts by weight White refined paraffin Limed rosin (4.75% Ca(OH)2) 20 Melt together until a clear melt is achieved, cool to a suitable dipping temperature, preferably not exceeding 275 F. Add dye-stuffs, etc., if so desired.

Splint strength 450 grams grams).

(untreated Example II Parts by weight White refined paraffin 83 Gilsonite 17 Color jet black. (untreated 150 Combine as under Example I. Splint strength 430 grams grams).

Example III Parts by weight White refined paraflin 61 Limed rosin 18 Gilsonite 18 (untreated 150 Example IV Parts by weight White paraffin 67 Limed rosin Opal wax '7 Carnauba wax 11 splint strength 520 grams (untreated 150 grams) I have found that with ordinary mat0h-board the most suitable temperature of impregnation for Example I is 240 to 260 F., the compound imparting to the stick a pleasing mat effect against a mottled appearance at higher temperatures, and increasing and useless surface impregnation at lower temperatures. Since, customarily, a paper match is held not lower than at the middle of the splint, it would suffice to immerse the splint to about /3 or even lessof the total length into the melt, and still benefit fully from the strengthening action. However, as a result of the stiffening action of the impregnants, and the penetration thereof to the base of the splint and the region of scoring line, the resulting match can be torn off much more readily, a fact that is very important in the case of the use of hard-pressed board of heavier caliper which presents a scoring problem.

It has also been found feasible to pre-im-' pregnate the board in the web on one or both sides preliminary to entering the punch-die with the same or a different Wax compound, the sheet taking up from 2% to 10% and, incidentally, promoting a cleaner cut edge and a better, smoother looking splint. Such pre-impregnation of the web alone will contribute only little to the improvement of strength and may not suffice for a satisfactory transfer of flame.

It is true that some efforts have heretofore been made to achieve greater stiffness in the match-splints by incorporation of stiffening agents directly into the paper as it is being made. For instance, various chemicals have been experimentally added to the pulp while in the beater. Such methods, however, are limited to certain types of soluble or dispersed resins or resin-wax combinations which can be precipitated more or less thoroughly by chemical reaction, and even then suffer losses in the white water of the paper machine. The amount of material thus incorporated into the fiber mass is neces sarily limited since higher percentages interfere seriously with the dehydration of the Web on the sieve, not to speak of the clogging up of screenwire, press and drying felts, and cylinders. Resin and waxes, incorporated in this manner, primarily improve tensile strength which is relatively unimportant in a match-splint and do not appreciably improve the stiffness, since the interstices between the fibers cannot be filled sufliciently to cause a material increase in rigidity. Lastly, even if such properties as achieved by the present invention were attainable by beater or paper machine application, it would be impossible to wind this board in the form of rolls due to the stiffness and brittleness of the final product.

In contradistinction to these conventional methods, imp-regnants of the present invention enter the individual splints from all points around the periphery thus being deposited primarily where the maximum increase of strength can be achieved. Due to thorough satiation of the interstices between the fibers, these impregnants create a state of rigidity and increase the breaking strength, which latter may reach 400 of the breaking strength of untreated match-board, thereby closely approximating the essential strength properties of white pine.

Although the present invention has been described primarily with reference to improvements in the manufacture of book matches, it should be understood that these same methods and improvements can, with equal facility, be applied to the manufacturing, from paper-board, of single splints which can be employed in making single splint matches which are competitively equivalent and, in many cases, superior to wooden matches.

It should also be understood that changes in the methods, compositions, percentages, and combinations above set forth may be made without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- A stiffening impregnant for paper-board having approximately the following composition:

Parts by weight White paraflin 6'7 Limed rosin 15 Opal wax 7 Carnauba wax 11 HERBERT EILEEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 16,256 Moscini Jan. 26, 1926 632,781 Mar Sept. 12, 1899 2,325,085 Vore July 27, 1943 2,325,167 Vore July 27, 1943