DE10044588A1 - Combustible ammunition molding production comprises precipitating raw felt from pulp, pressing felt to desired thickness, and pressing it to its final thickness, followed by drying - Google Patents

Abstract

Production of a combustible ammunition molding (13) comprises precipitating a water containing raw felt (4) from a pulp, and then pressing the felt to the desired wall strength and drying. Pressing comprises at least two stages. In the first stage the felt is pressed to the desired thickness, so the pre-compressed raw sleeve (8) still contains water and can be formed. The sleeve is then pressed to its final thickness during the second stage, and dried.

Description

The invention relates to a method for producing a combustible ammunition mold part according to the preamble of claim 1.

It is known to use cellulose, nitrocellulose and synthetic fibers Plastic binders, e.g. B. polyurethanes, by technically known felting flammable molded ammunition, such as propellant charge cases, ignition tubes and the like. Like. To produce. With the exception of the binder, if necessary, all components are suspended in water and from the resulting pulp the raw felt from the aqueous slurry made by immersion and suction on a mandrel. Then the Raw felt is compressed in a heated press and dried, and the raw tube obtained then impregnated.

In the known methods, the raw felt is usually pressed in one single-stage compression process, z. B. for the production of combustible propellant Large-caliber ammunition sleeves (e.g. 120 mm KE tank ammunition) with a wall presses heated by 3 mm with a pressing force of 70 tons can be used. Since the wall thickness must not exceed a tolerance of ± 10% and such Muni tools have a length of approx. 60 cm, the tools of the press need a lot  be guided precisely (precision process).

A reduction in the wall thickness of such combustible sleeves from 3 to 2 mm to to increase the amount of propellant charge to be placed in the sleeve and thus a power To increase the corresponding ammunition is to increase the pressing force connected. This can only be achieved with a larger sized press, however usually does not have the required precision. There is also a risk that when using a one-step process by means of a heated press due to the high load on the felt the raw felt tears.

The invention has for its object a method of the type mentioned admit with the smaller wall thickness without complex pressing work and pressing tools ken of the respective molded ammunition than can be produced with known molded ammunition are. In addition, the tolerance of the wall thickness of the respective molded part should according to the Conventional procedures manufactured ammunition molded parts, with none Tear the raw felt may come during the pressing process.

This object is achieved by the features of claim 1. width re, particularly advantageous embodiments of the invention disclose the dependent claims.

The invention is essentially based on the idea that the pressing process does not occur fig, but to be carried out at least in two stages. The raw felt is in a first Partial pressing process with a press without drying the felt to a first wall thickness pre-compressed value, the z. B. corresponds to that of the prior art (z. B. 3 mm). Then the pre-compressed raw sleeve is then in a second part pressing process compressed to the final dimension and thereby or subsequently heated or ge dries.

This two-stage compression results in the following advantages, among others:

• - The pre-compression to z. B. 3 to 4 mm increases the stability of the raw sleeve by itself the compressed packing of the fiber material, so that the maximum permissible load  of the felt during the compression process in the second compression stage is taken.
• - The effort is significantly reduced in the second compression stage because of Compression factor is only 1.5 to 2. In the case of a one-step process this compression factor, however, is approximately 4.0.

Further details and advantages of the invention will become apparent from the following a figure illustrated embodiment for producing a large-caliber burn removable cartridge case (e.g. 120 mm tank ammunition) with a wall thickness of 2 mm.

In the figure, 1 denotes a storage tank in which a suspension (make-up pulp) made of kraft pulp, nitrocellulose, water and a stabilizer is contained. To produce the cartridge case, a corresponding part of the pulp is poured into a felting container 2 , in which a shaping mandrel 3 is located. Through openings (not shown) in the mandrel 3 , the pulp is sucked towards the mandrel 3 , so that an outer contour of the mandrel 3 corresponding raw felt 4 is formed on the upper surface thereof.

The wet raw felt 4 is removed from the felting container 2 and positioned on the lower stem 5 of a press 6 . The press 6 is then closed by pressing on a first upper punch 7 and the raw felt 4 is pre-compressed into a raw sleeve 8 . The pressing force is chosen such that the wall thickness of the raw sleeve 8 is reduced from initially approximately 8 to approximately 3 mm. The pressing process takes place without drying the raw sleeve 8 . Only the excess water is pressed out of the felt of the raw sleeve 8 .

After the first partial pressing operation, the first upper punch 7 is removed from the press 6 and a second upper punch 9 is pressed onto the pre-compressed raw sleeve 8 . The pressing force is chosen in this case such that the wall thickness of the raw sleeve 8 reaches its final dimension of 2 mm by appropriate redensification.

The press 6 is evacuated either during the pressing process or after its termination for dewatering and drying and heated to a temperature of 120 ° C.

The raw sleeve 8 is then removed from the press 6 and impregnated in an impregnation bath 10 with polyurethane removed from a container 11 .

If necessary, a (mechanical) finishing of the raw sleeve can finally take place in a mechanical processing station 12 and the finished cartridge sleeve 13 can then be transported to a warehouse.

The invention is of course not based on the embodiment described above example limited.

If, for example, it turns out that the rapid combustion by the compression Availability of the molded ammunition part and / or residues occur, so the Proportion of nitrocellulose can be increased somewhat at the expense of kraft pulp. The mechanical strength of the molded part, which is essentially due to the proportion of kraft pulp is then determined, for example, by impregnation under vacuum conditions are increased.  

LIST OF REFERENCE NUMBERS

1

storage tank

2

Verfilzungsbehälter

3

Shaped mandrel, mandrel

4

raw felt

5

lower punch

6

Press

7

first upper stamp

8th

Rohhülse

9

second upper stamp

10

impregnation

11

container

12

mechanical processing station

13

Cartridge case, ammunition molding

Claims (3)

1. A method for producing a combustible ammunition molded part ( 13 ), in which a water-containing raw felt ( 4 ) is first deposited from a batch pulp from the corresponding substance components, which is then compressed to a predetermined wall thickness by a pressing process and is dried simultaneously or subsequently, characterized in that the pressing process comprises at least two partial pressing operations, the raw felt ( 4 ) being compressed in a first partial pressing operation without drying to a first wall thickness value, so that the resulting pre-sealed raw sleeve ( 8 ) remains water-containing and thus malleable, and that then the pre-compressed raw sleeve ( 8 ) is compressed to its final wall thickness value in a second partial pressing process and is dried only during this compression process or after completion of this compression process. 2. The method according to claim 1, characterized in that the pressing force in the second partial pressing process is selected such that the pre-compressed raw sleeve ( 8 ) is compressed by a factor between 1.5 to 2. 3. The method according to claim 1 or 2, characterized in that for the production of a combustible sleeve for large-caliber tank ammunition with a wall thickness of 2 mm in the first partial pressing process, the pressing force is chosen such that the pre-compressed raw sleeve ( 8 ) has a wall thickness of 3 to 3 , 5 mm.