RU2666852C2 - Method of preparing thermoplastic energy composition - Google Patents

Abstract

FIELD: manufacturing technology.SUBSTANCE: invention relates to a process for preparing energy compositions. After dosing the binder, powdered components are dispensed into the blade mixer with the jacket, while the mixing of each portion of the powdered components with a thermoplastic binder in a viscous flow state is carried out in a heated mixer with subsequent grinding of the finished composition with the supply of cooling liquid to the shafts and the mixer jacket until the power consumption is stabilized.EFFECT: method allows to reduce technological losses when unloading the finished composition from the mixing equipment.1 cl

Description

The invention relates to the field of preparation of thermoplastic energy compositions, including explosive compositions using a thermoplastic binder, and can be used in chemical, defense and other industries.

The method can be applied in the manufacture of compositions for engineering ammunition and other products of a similar purpose.

Thermoplastic energy compositions along with powder components (metals, oxidizing agents, explosives) contain polymeric materials or mixtures of several polymers, which transform into a plastic viscous flow state when heated. When cooled, the composition loses its plastic properties and becomes solid.

The formation of products from thermoplastic energy compositions by pressing in closed molds remains the most simple and universal way to obtain products of various shapes that do not require sophisticated equipment, easily implemented in mass production.

The dispersion of particles has a significant effect on the density of pressed products; therefore, preliminary grinding of the compositions before pressing is required.

A known method of mixing components of an explosive composition according to the patent of the Russian Federation No. 22259982 class. C06B 21/00, publ. 09/10/2005 (prototype), according to which the mixing method involves preparing liquid-viscous and powdery components, portioning the liquid-viscous components into the mixer, dispensing the powdery components into the mixer, first with large and then with a small particle size, mixing each portion of the powdery components with liquid-viscous components ( binder).

In the manufacture of thermoplastic energy compositions by this method, unresolved issues regarding unloading and further grinding of the composition remain unresolved. As shown by the practice of manufacturing thermoplastic compounds in mixing equipment, when it is unloaded from the mixing equipment, about 1/3 of the composition remains on the shafts of the mixer. The unloading of the energy composition in a plastic state is carried out in the form of pieces of unregulated sizes. After cooling, the unloaded pieces require additional grinding.

In the literature, there are known methods of grinding compositions (explosive materials) in devices whose working bodies are two rotors rotating towards each other with a set of disks similar to mills (RF patent No. 2077131 class. B02C 13/22, publ. 04/10/1997, No. 2102364 class C06B 21/00, publ. 01/20/1998, utility model No. 17918 C. C06B 21/00, publ. 05/10/2001), or disks installed with a gap between each other and offset by step (RF patent No. 2111198 class. C06B 21/00, published on January 20, 1998).

Also known are methods of grinding elastomers by pre-cooling them (application for invention No. 95101194 class B29B 17/00, publ. 01.27.1997).

The technical result of the proposed method is the development of a method for preparing a thermoplastic energy composition, which allows to reduce technological losses during unloading of the finished composition from mixing equipment.

The specified technical result is achieved in that the grinding of the energy composition is carried out immediately after its preparation in the same mixing equipment.

The preparation of a thermoplastic energy composition includes the preparation of a binder and powder components, dosing the binder into the mixer, dosing the powder components, mixing each portion of the powder components with a thermoplastic binder in a heated mixer with load control on the mixer drive until the power consumption is stabilized, which indicates the completion of the grinding process.

Immediately after the preparation of the composition in the same mixer, it is crushed by mixing while supplying coolant to the jacket and shafts of the mixer. When the composition is cooled, its viscosity increases, ductility decreases, and it passes from a plastic state to a solid state and begins to crush upon shear action of shafts with blades.

The following are examples of the preparation of the composition of the prototype and the proposed solution.

Prototype Experience

In a pre-warmed up to (70-80) ° С double-shaft paddle mixer, the binder was first loaded - divinyl styrene thermoplastic elastomer plasticized with industrial oil, then, after the binder was transferred from elastic to viscous-flowing state, powdery components, including explosive ones, were sequentially loaded. First of all, portions of coarse components were loaded. Mixing each portion of the powdered components with a binder was carried out until the mixture reached a temperature of 90 ° C. Mixing after loading the last portion was also carried out until the mixture reached a temperature of 90 ° C, then - until the stabilization of the power consumption value. The composition was unloaded using the unloading auger in the form of pieces of an unregulated form. About 1/3 of the composition remained on the shafts of the mixer, which was unloaded manually. After cooling the composition, its grinding was carried out in other equipment.

The experience showed the possibility of manufacturing a thermoplastic energy composition. However, in the manufacture of thermoplastic compositions by this method, unresolved issues of unloading and further grinding of the composition remain unresolved.

Experiments on the proposed technical solution

Mixing after loading the last portion of the dispersed components was carried out until the mixture reached a temperature of 90 ° C, then - until the stabilization of the power consumption, as described above.

Then, after preparation of the composition in the same equipment, it was crushed by stirring when water was supplied at a temperature of (10-15) ° C into the jacket and shafts of the mixer or other coolant until the mixture reached a temperature of (40-50) ° C. Grinding was carried out to stabilize the amount of power consumed.

When sieving the powdered energy composition thus prepared, the following quantitative size distribution was obtained:

- 46% with a particle size of 5 to 10 mm;

- 54% with a size of less than 5 mm.

With this method of preparation of the composition is achieved almost complete unloading from the mixing equipment. The resulting composition does not require additional grinding and can be used to form products by pressing.

Claims (2)

1. A method of preparing a thermoplastic energy composition, including preparing a binder and powder components, dispensing a binder in a paddle mixer with a jacket, dispensing powder components, wherein each portion of the powdered components with a thermoplastic binder is mixed in a viscous-flowing state in a heated mixer, followed by grinding of the finished composition when coolant is supplied to the shafts and the mixer jacket until the value stabilizes th power. 2. The method according to p. 1, characterized in that the mixing is carried out at a temperature of 90 ° C.