Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B21/00—Apparatus or methods for working-up explosives, e.g. forming, cutting, drying
  • C06B21/0091—Elimination of undesirable or temporary components of an intermediate or finished product, e.g. making porous or low density products, purifying, stabilising, drying; Deactivating; Reclaiming
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B25/00—Compositions containing a nitrated organic compound
  • C06B25/18—Compositions containing a nitrated organic compound the compound being nitrocellulose present as 10% or more by weight of the total composition
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S102/00—Ammunition and explosives
  • Y10S102/70—Combustilbe cartridge

Definitions

• ABSTRACT A dry compacted Caseless Propellant Charge comprising in addition to the usual constituents of a propellant explosive, a proportion of nitrocellulose having an average nitrogen content of l 1.0 to 12.0 percent by weight.
• caseless propellant charges as the power source for projectiles and for explosive percussion tools such as nail guns.
• the design of a satisfactory unitary propellant charge having ballistic properties comparable to those of a granular charge presents many problems and as yet caseless charges have not captured any significant proportion of the market.
• a caseless charge must be designed so that, on ignition, burning will not be limited to the surface of the charge but will occur throughout the mass as in a loose charge.
• individual grains of propellant explosive composition are compacted either dry or treated with plasticiser or solvent to stick the grains together in a coherent mass.
• the degree of compaction is intended to be such as to bind the grains sufficiently to prevent breakage in normal handling but to leave the charge sufficiently friable that the grains separate and burn as a loose charge on actuation of the primer which is used to ignite the charge. It is extremely difficult to achieve a balance of the many factors involved so as to produce a satisfactory commercial charge which will burn reliably without leaving a residue which can jam breech mechanism of a nail gun.
• propellant grains containing a proportion of nitrocellulose having an average nitrogen content of 1 1.0 to 12.0% N by weight can be dry compacte d without solvent or adhesives to gi e irnproved unitary caseless propellant charges.
• the charges disintegrate more reliably under the action of the primer to simulate the ballistic effect of a loose charge better than compacted charges hitherto available, and they can be handled in normal use without substantial loss due to breakage.
• the propellant explosive composition of this invention comprises, in addition to the usual constituents of a nitrocellulose based propellant explosive, a proportion of low nitrogen nitrocellulose having an average nitrogen content of 11.0 to 12.0 percent by weight.
• the propellant may conveniently be a singlebase propellant based on high nitrogen nitrocellulose having an average nitrogen content of 13.2 to 13.4 percent by weight (guncotton), a double-base propellant containing nitroglycerine and guncotton nitrocellulose or a triple-base propellant containing nitroguanidine, nitroglycerine and guncotton nitrocellulose.
• the proportion of low nitrogen nitrocellulose is within the range to 30 percent by weight of the total composition.
• the invention includes a unitary caseless propellant charge comprising compacted grains of the aforedescribed propellant composition.
• the charge is conveniently cylindrical. If desired for convenience, the charge may be formed with a surface indent to accommodate an appropriate quantity of a priming composition.
• the invention also includes a method of making a unitary caseless propellant charge which method comprises dry compacting grains of a propellant composition containing, in addition to the usual constituents of a propellant explosive, a proportion of low nitrogen nitrocellulose having an average nitrogen content of l 1.0 to 12.0 percent by weight.
• the grains are compacted at a pressure within the range 30,000 to 70,000 psi.
• the propellant composition may be prepared in gran ular form in conventional manner, for example by incorporating into the composition a solvent or plasticiser for the nitrocellulose constitutents to form a dough and shaping the dough into the required grain by moulding or extrusion as a cord which is subsequently divided.
• the grains may advantageously be porous.
• the porosity may be achieved in known manner by initially including a removable filler in the composition which is subsequently removed from the grains.
• potassium nitrate crystals may be included and re moved by leaching out of the grains with water.
• the amount of filler is preferably in the range 50 to 200 parts per parts by weight of the composition.
• EXAMPLE I 84 parts (as dry) of guncotton nitrocellulose having an average nitrogen content of 13.3% N vetted with 44 parts of ethyl alcohol, 15 parts of low nitrogen nitrocellulose containing an average of l 1.6 to l 1.8% N, 1 part of diphenylamine, 100 parts of potassium nitrate and 66 parts of diethyl ether were mixed to form an extrudable dough. The dough was extruded through a die to form a cord 1.4 mm diameter which was air dried and cut into disc-shaped grains of approximate thickness 0.32 mm. These grains were stepped in hot water (60C) to remove most of the potassium nitrate and air dried.
• the primer indent of each charge was filled with a priming composition consisting of 64 parts of lead styphnate and 36 parts of ground glass slurried in a solution of nitrocellulose. The slurry was dried and covered with a thin protective coating of collodion.
• the caseless propellant charge of this Example was tested in an explosively actuated nail driving gun and it burned cleanly and had ballistic properties comparable to a corresponding loose granular charge. It withstood normal rough handling without breakage.
• EXAMPLE ll 74 parts (as dry) of guncotton nitrocellulose having an average nitrogen content of 13.3% N wetted with 40 parts of ethyl alcohol, 25 parts of low nitrogen nitrocellulose containing an average of l 1.8 to 12.0% N, 1 part of diphenylamine, 50 parts of potassium nitrate and 60 parts of diethyl ether were mixed to form an extrudable dough. The dough was formed into grains which were steeped to remove the potassium nitrate and glazed as described in Example I.
• the composition of the resulting grains was Guncotton nitrocellulose 74 parts Low nitrogen nitrocellulose 25 parts Diphenylamine l part Potassium nitrate l part Graphite 0.4 part 0.30 gram quantities of the grains were pressed in a mould at a pressure of 40,000 psi to form cylindrical unitary charges of approximately the same shape and dimensions as the pressed charges of Example I.
• EXAMPLE III 59 parts of guncotton nitrocellulose having an average nitrogen content of 13.3 percent, parts of low nitrogen nitro-cellulose (average N content 11.5 percent) and 1 part of ethyl centralite were slurried with 800 parts of water and 20 parts of nitroglycerine were mixed into the slurry to form a paste. The paste was dried in hot air, mixed with 36 parts of acetone and four parts water and 200 parts of potassium nitrate were added to form a dough which was extruded and granulated as in Example I. The grains were steeped in hot water (60C) to remove the potassium nitrate and were subsequently air dried and glazed as described in Example I.
• the composition of the grains was Guncotton nitrocellulose 59 parts Low nitrogen nitrocellulose 20 parts Nitroglycerine 20 parts Ethyl centralite 1 part Potassium nitrate 1 part Graphite 0.4 part.
• EXAMPLE IV 69 parts of guncotton nitrocellulose having an average nitrogen content of 13.3 percent, 15 parts of low nitrogen nitrocellulose containing an average of l 1.2 to 11.4% N, and 1 part of ethyl centralite were slurried with 800 parts of water and 15 parts of nitroglycerine were mixed into the slurry to form a paste.
• the paste was dried in hot air, mixed with 40 parts of acetone and 8 parts of water and parts of potassium nitrate were added to form an extrudable dough.
• the dough was formed into grains which were steeped to remove the potassium nitrate and glazed as described in Example I.
• the composition of the grains was Guncotton nitrocellulose 69 parts Low nitrogen nitrocellulose 15 parts Nitroglycerine 15 parts Ethyl centralite 1 part Potassium nitrate 1 part Graphite 0.4 part 0.35 gram quantities of the grains were pressed in a mould at a pressure of 60,000 psi to form cylindrical unitary charges of approximately the same shape and dimensions as the pressed charges of Example I.
• a unitary caseless propellant charge consisting of dry compacted grains of a propellant composition comprising a high nitrogen content nitrocellulose and 10 to 30 percent by weight ofa nitrocellulose of l 1 to 12 percent nitrogen content by weight.
• a propellant charge as claimed in claim 1 formed with a surface indent to accommodate an appropriate quantity of a priming composition.
• a method of making a unitary caseless propellant charge which method comprises dry compacting grains of the composition of claim 1 at pressures in the range of 30,000 to 70,000 psi.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Cosmetics (AREA)
• Toys (AREA)
• Medicinal Preparation (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10427693

Family Applications (1)

Country Status (10)

Cited By (8)

Families Citing this family (32)

Citations (4)

• 0
  • BE BE788664D patent/BE788664A/xx unknown
• 1971
  • 1971-09-16 GB GB4318871A patent/GB1349547A/en not_active Expired
• 1972
  • 1972-08-18 ZA ZA725691A patent/ZA725691B/xx unknown
  • 1972-08-21 US US00282057A patent/US3779820A/en not_active Expired - Lifetime
  • 1972-08-24 AU AU45935/72A patent/AU466642B2/en not_active Expired
  • 1972-09-13 IT IT29140/72A patent/IT967416B/it active
  • 1972-09-15 FR FR7232796A patent/FR2153039B1/fr not_active Expired
  • 1972-09-15 CA CA151,871A patent/CA984155A/en not_active Expired
  • 1972-09-15 DE DE2245510A patent/DE2245510B2/de not_active Ceased
  • 1972-09-16 JP JP47093130A patent/JPS4836313A/ja active Pending

Patent Citations (4)

Also Published As

Similar Documents