US1594861A - Dynamite composition - Google Patents

Description

Patented Aug. 3, 1926.. l

' UNITED}: STATES I 1,594,851 Paras-r orrica.

WENDELL R. SWINE, OF WHIHINGTON, DELAWARE, ASSIGNOB 'I'O E. I. DU PONT DE moons &. GOHPANY, OF WILMINGTON, DELAWARE, A. CORPORATION OF'DELA- WABE.

Ho Drawing.

This invention relates to dynamite composltions, and consists essentially in the use of ,balsa wood as a new absorbentmaterial for the liquid high explosive component of dy- 8 namite.

In an ordinary dynamite containing nitroglycerine, the material used to absorb nitroglycerine will depend upon the percentage of nitroglycerine in the explosive. Thus, 10 for example, a so-called straight dynamite containing 60% of nitroglycerine usually contains approximately 18% of wood flour or. wood pulp, whereas a dynamite containing 40% nitroglycerine may contain about 10% of wood our or wood pulp, and a dynamite containing of nitrogl cerine may be made without any wood our or wood pulp at all, the other in edients such as sodium nitrate, corn meal, our, etc., having suificient power of absorption to retain the nitroglycerine without the latter exuding from the dynamite. i

have discovered thatdynamites having new and distinctive properties may be obi tained by using finely divided balsa wood as the chief absorbent material for the nitroglycerine or other liquid high explosive constituent. -My invention contemplates the use of balsa wood, repared in a way to be described below, 1n place of all or a part of the wood pul or wood flour ordinarily used. Balsa. wood Ochroma Zagopue) is a tropical wood which is distinctive in that it has a very low specific gravity. Commercial balsa 5 wood hasa specific gravity of from 0.115-

0130. The reason for this extreme lightness is its loose structure and the softness of its tissue. '1 have found that if balsa wood is subjected to the ordinary procedure in manufacturing wood flour, such as grinding in suitable mills, for example buhrstone mills or other suitable attrition mills, the wood pul or wood flour so produced retains the 'ghtness of the original wood and J provides a very satisfactory absorbent for nitroglycerine. Because of the extreme lightness of the wood flour or wood pulp so produced, a given weight will absorb a higher percentage of nitroglycerine than will l wood pulp or wood flour made from ordinary wood, such as spruce, fir, pine, etc. taking advantage of this fact, I can produce a 60% dynamite containing a lower .percentage of wood pulp or wood flour than is fineness.

DYNAMITE COMPOSITION. I

Application filed April 18, 1922. Serial No. SIS 2,844.

ordinarily used when wood pulp or wood flour made from ordinary northern woods is employed. Thus, for example, a dynamit e can be made with from 12-15% of wood flour made from balsa wood as compared with 20% of wood pulp or wood flour made from ordinary northern woods.

I have also discovered that sawdust produced as a waste product of balsa wood by, the ordinary methods of wood working may be used to great advantage in dynamite compositions where the .percentage of nitroglycerine is not high, and where a lowdensity explosive is desired. Thus, for example, in explosives of the permissible type such as are used in coal mines, it is sometimes desirable touse a very low density explosive. The explosives now in use ordinarily have a density corresponding toa weight of 160-180 grams for a cartridge 1%" in diameter by t 8" long. B the use of a specially high grade wood our or wood pulp, it is possible to obtain a density corresponding to a weight of about 145 grams for a cartridge 1 A in diameter .by 8" long.- I have discovered that by using sawdust made from balsa wood, I can produce a permissible explosive having a density correspondingto a weight of approximately 125 grams for a cartridge 1%" in diameter by 8' long. The sawdust for use in compositions of this type may vary within quite widelimits as to That which I have found to be most suitable is of such afineness that none 'isheld on a 10 mesh screen and from '10- 30% passes a-40 mesh screen. Similar results can be obtained, using 'wood flour or wood pulp made from balsa wood. Asanexample of such an explosive, I cite the following Per cent. Nitroglycerine 10' Ammonium nitrate 75 Sodium nitrate 5 Balsa wood sawdust 10 It will, of course, be understood that I may vary this-composition greatly without departing from the spirit of the. invention. Thus,'for example, I may use tetranitrodi-- glycerine in place of-nitroglycerine in order to make the ex losive low reezing, or I may omit sodium nitrate entirely or mc'rease its percentage appreciably. Instead of sodium nitrate, I may use sodium chloride or I may use any of the well-known methods for depressing the temperature of the flame in order to secure an explosive which will be safe to use in dusty and gaseous coal mines. For a portion of the balsa wood, I may substitute other carbonaceous materials, such as corn meal, ivory nut meal, flour, etc.

The most important ranges of proportions may be indicated as follows (for permissible explosives) I Percent. Nitroglycerine from 7-15 Ammonium nitrate from 4085 Sodium nitrate from 20 Sodium chloride "from" 0-20 Balsa wood pulp or flour fi'om -15 I claim:

1. An explosive composition characterized b its low density and comprisin from about 7 to of a normally liqu1d high explosive, from about 5 to 15% of finely divided balsa wood, and ammonium nitrate.

2. An explosive composition characterized b its low density and comprisin from aliout 7 to 15% of a normally liquid hi h explosive, from about 5 to 15% of finely ivided balsa wood, from 40 to 85% of ammonium nitrate, and a salt adapted to reduce the flame temperature upon explosion of the composition.

3. An explosive composition characterized by its low density about 7 to 15% of nitroglycerine, from about 5 to 15% of finely divided balsa wood, and ammonium nitrat 4. An explosive composition characterized by its low density and comprisin about 10% of nitroglycerine, about 75% o ammonium nitrate, about 5% of sodium nitrate, and about 10% of finely divided balsa wood.

In testimony whereof I aflix my signature.

WENDELL R. SWINT.

and comprising from,