RU2655315C1 - Method for obtaining a rigid combustible bag - Google Patents

Abstract

FIELD: manufacturing technology.

SUBSTANCE: invention relates to the field of production of products from powder-fiber composition energy materials, including profiled ones. Method includes the preparation of an aqueous suspension of fibrous materials, forming a wet article by depositing fibers and dispersed components on a molding base and removing residual moisture by drying. In this case, a 0.8–1.1 % aqueous suspension is supplied at a pressure of 98.1–196.2 kPa per molding matrix. Brass net of a special structure is inserted into the molding matrix to create vertical cuts with a smaller thickness of the material on the inner surface of the bag. Net cells are sealed in a vertical direction in those places where it is necessary to create cuts on the bag, the width of a sealed band is 4–5 mm, the number of bands is 4–12.

EFFECT: technical result consists in obtaining a rigid combustible bag with vertical bands on the lateral inner surface of the bag, having a lower density of the material, which makes it possible to predict the number of elements of the decay of the rigid combustible bag at the time of the shot.

1 cl, 2 dwg, 1 tbl

Description

The invention relates to the field of production of products from powder fiber composite energy materials, including profiled.

A known method of applying the potassium salt of 4,6-dinitro-5,7-dioxibenzo-furoxan on cellulose nitrate fibers in water-dimethyl sulfoxide in the presence of 0.2-1.5 wt. % surfactant with respect to water at a temperature of 60-65 ° C [1]. The disadvantage of this method is the use of an organic solvent, which is not possible to use for the manufacture of rigid combustible sacks using filtration casting technology.

In the patent [2], a method for producing a propellant porous charge is proposed, which includes preparing an aqueous polymer solution, preparing a mixture of components, molding charges from the resulting mixture by compression, removing water by drying, characterized in that the composition is made from water-moist unplasticized fibers of cellulose nitrate (SC) , as the polymer used is a water-soluble polymer of synthetic or natural origin in an amount of not more than 25 wt. %, and as a filler - blasting explosives in an amount of not more than 70 wt. % The disadvantage of this method is the use of a water-soluble polymer, and aqueous suspensions of the components are used in the filtration casting technology.

The closest technical solution (prototype) is a method of manufacturing molded products from pulp according to the patent [3], which includes preparing an aqueous suspension of the desired concentration from fibrous materials, molding a wet product by depositing fibers on a forming base and removing residual moisture by drying. Liquid and solid modifiers are metered into the prepared aqueous suspension to give the material the required physical and mechanical qualities, the fibers are deposited on the surface of solid-state forms made of porous material, and the formation of a wet product is carried out on the lower surface of the forming base according to the bottom-up scheme by building fibrous material by filtering water from the suspension through the pores of the forming base due to the pressure drop created on it, while simultaneously with drying the product is subjected to prepressing, and drying the product is carried out in a heated detachable solid-state form with the simultaneous removal of water vapor due to vacuum pumping from the upper and lower parts of the specified detachable form.

The disadvantage of this method is that in a porous solid-state form with a uniform distribution of pores in the volume it is impossible to obtain burning elements with different density of the walls of the product. In addition, drying is carried out in a detachable solid state form, from the upper and lower parts of which vacuum is pumped out. When this form of connector is used, the workpiece in the dry state is difficult to remove from the forming base,

The objective of the invention is to obtain a hard burning cap with vertical stripes on the side inner surface of the cap having a lower material density, which allows us to predict the number of decay elements of the hard burning cap at the time of the shot.

The problem is solved due to the fact that the method of obtaining a hard burning cap, including the preparation of an aqueous suspension of fibrous materials, molding a wet product by depositing fibers and dispersed components on a forming base and removing residual moisture by drying, differs in that 0.8-1.1% the aqueous suspension is supplied under a pressure of 98.1-196.2 kPa to a forming matrix into which a specially designed brass mesh is inserted to create vertical notches with a smaller material thickness on the lateral inner surface and his cap, this brass mesh cell sealed in the vertical direction in those places where it is necessary to create notches on cap, sealed strip width is 4-5 mm, the number of lanes 4-12.

Due to the fact that the material of the hard burning cap (HCC) is energetic, in the process of firing six modules of the propellant charge during its combustion in the gun’s chamber, the pressure of the powder gases additionally increases by ~ 4.9 MPa (500 atm). Vertical stripes of lower density on the lateral surface of the HBC make it possible to predict the number of decay elements of the hard burning cap at the time of the shot and thereby change the nature of the combustion of the product in the gun’s chamber. Thus, a smaller dispersion in the pressure of the powder gases created at the time of the shot is achieved.

Examples of a method for manufacturing a rigid burning cap with vertical notches with a lower density of material on the side (peripheral) surface of the cap are shown in the table.

An aqueous suspension with a concentration of 0.8%, consisting of cellulose, milled up to 42-48 ° C (Schoper Riegler), binder and energy-saturated materials is mixed in a mixer, then through the pipeline (Fig. 1, item 1), the suspension flows from bottom to top molding tool (pos. 2) under pressure of 98.1 kPa, in which there is a reflector (pos. 3), from which the suspension is reflected and enters the internal cavity of the forming matrix (pos. 4), which has drainage holes (pos. 5 ), to filter the suspension, a brass mesh (pos. 6) with cf. the single mesh size is 0.54 mm. To create notches, the brass mesh is soldered in the form of vertical (longitudinal) strips along the height of the forming tooling, the width of the soldered strip is 4-5 mm, the number of vertical (longitudinal) diametrically strips on the side surface is from 4 to 12.

So, when filtering a suspension with a concentration of 0.8% through a forming matrix, where there is a continuous (soldered) surface of the strip on a brass grid, the suspension is flowing onto this surface. Thus, the HBC blank (Fig. 1, item 7) after molding has a different wall thickness. Where filtration occurs freely, the thickness of the preform is 7-8 mm, and where there is an influx of filtrate, the thickness is 5-6 mm, respectively. The appearance of the molded product with notches on the inner side surface is shown in FIG. 2.

The obtained molded billets of the hard burning cap are dried to constant weight and pressed in a thermal press to obtain the final shape and density of the material of the hard burning cap.

At the final pressing, the wall thickness of the side surface of the finished product around the circumference is similar, and the density of the material in the locations of the vertical stripes is less by 0.2-0.25 g / cm ³ . On the remaining surface of the HCC, the density of the material is 0.9-0.95 g / cm ³ . The wall thickness of the finished HBC is 2.2-2.6 mm.

The molding pressure varies depending on the concentration of the fibrous suspension from 98.1 to 198.2 kPa. The higher the concentration of the suspension, the greater the pressure necessary to create for its submission to the matrix (examples 1-3).

A decrease in suspension concentration of less than 0.8% reduces the productivity of the installation (molding time increases to 70-80 s instead of 40-50 s), and an increase of more than 1.1% leads to an uneven thickness of the workpiece after molding.

An increase in the number of continuous bands of more than 12 can lead to uneven decay of a hard burning cap at the time of the shot. With an increase in the bandwidth of more than 5 mm, through holes in the HCC material can form due to the low density. Then the HBC will not be guaranteed to protect the main propellant charge from external influences. If the strip width is reduced to less than 4 mm, the density will be negligible, which can also lead to uneven decay of the hard burning cap at the time of the shot.

The table shows that due to the presence of continuous vertical stripes on the brass grid, it is possible to control the nature of the density change of the material of the side surface of the HBC, and by varying the number of vertical stripes - the number of decay elements of the shell at the time of the shot.

Obtained by the developed method, a hard burning cap with a different density of material of the side surface allows us to predict the number of decay elements of a hard burning cap at the time of the shot, that is, the nature of the burning of hull in the gun chamber.

Literature

1. RF patent No. 2473566. IPC С08В 15/00, С06В 21/00. The method of obtaining filled cellulose nitrates / T.A. Eneykina, L.M. Yusupova, R.F. Gatina, A.I. Khatsrinov and D.R. - declared. 04/05/2011, publ. 01/27/2013.

2. RF patent No. 2382019. IPC С06В 21/00, С06В 25/00. Block propellant porous charge (options) and method of its manufacture / V.V. Namestnikov I.V. Krivenko, Yu.M. Filippov. - declared. 05/30/2008, publ. 02/20/2010.

3. RF patent No. 2270895 of 02.27.2006, IPC D21J. A method of manufacturing molded products from pulp / Martynov V.N., Lankov A.E., Martynov S.N. - Application No. 2004117922 of 06/15/2004.

Claims (1)

A method of obtaining a rigid combustible cap, comprising preparing an aqueous suspension of fibrous materials, molding a wet product by depositing fibers and dispersed components on a forming base and removing residual moisture by drying, characterized in that a 0.8-1.1% aqueous suspension is supplied under pressure 98.1-196.2 kPa per forming matrix, into which a specially designed brass mesh is inserted to create vertical notches with a lower material density on the side inner surface of the cap, for this cell l the atomic mesh is sealed in the vertical direction in those places where it is necessary to create notches on the cap, while the width of the sealed strip is 4-5 mm, the number of strips is 4-12.

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