Prefabricated Explosive Grain Casting Process

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Solution Overview

Problem

Current methods for casting explosive materials with reduced vulnerability are complex, expensive, and difficult to demilitarize, requiring precise control of material associations and casting parameters, especially for fusionable explosives that incorporate high proportions of phlegmatizers and emulsifiers, making them challenging to implement and recycle.

Innovation Solution

A method involving prefabricated grains of explosive material with reduced vulnerability, comprising a solid phase and a fusionable phase, where the grains are heated and stirred in a melting tank under vacuum to ensure homogeneous emulsion and simplified casting, using a mixture of trinitrotoluene, oxinitrotriazole, and a phlegmatizer, with optional aluminum powder and emulsifier, allowing for easier implementation with conventional equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fusion explosive processes are used to create homogeneous emulsion with high proportion of phlegmatizer, then the explosive material achieves reduced vulnerability, but the manufacturing process becomes complex and requires precise control of multiple parameters

Engineering Contradiction:
Improvereduced vulnerabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-coating solid explosive particles with the phlegmatizer-emulsifier mixture before mixing with the fusible explosive. This pre-coating step ensures that the solid particles are already protected when the final mixture is prepared, eliminating the need for complex vigorous stirring and emulsification processes during final mixing. The pre-coated particles maintain their protective coating throughout the casting process, achieving reduced vulnerability without complex manufacturing control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the manufacturing process into distinct stages: first preparing and applying the phlegmatizer-emulsifier coating to solid explosive particles, then separately preparing the fusible explosive mixture, and finally combining them. This segmentation allows each component to be optimized independently - the coating can be precisely controlled on individual particles while the bulk mixture can be simply mixed and cast, greatly reducing overall process complexity while maintaining the homogeneous distribution needed for reduced vulnerability.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If solid explosive particles are mixed with fusible explosive and phlegmatizer requiring vigorous stirring, then homogeneous composition is achieved, but the process requires precise temperature control and complex equipment

Engineering Contradiction:
Improvehomogeneous compositionVSAvoidease of implementation
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-coating solid explosive particles with the phlegmatizer-emulsifier mixture before mixing with the fusible explosive. This pre-coating step ensures that the solid particles are already protected when the final mixture is prepared, eliminating the need for complex vigorous stirring and emulsification processes during final mixing. The pre-coated particles maintain their protective coating throughout the casting process, achieving reduced vulnerability without complex manufacturing control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical state parameters by conducting the coating process at temperatures above the melting point of the phlegmatizer, allowing it to flow and coat particles uniformly. During final mixing and casting, the temperature is maintained above the melting point of the fusible explosive, ensuring fluidity and homogeneous distribution. This parameter control simplifies the process by using temperature-driven phase changes rather than mechanical emulsification.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If prefabricated grains are used to simplify casting, then the process becomes easier to implement, but the grains must maintain structural integrity during heating and stirring

Engineering Contradiction:
Improveease of castingVSAvoidstructural integrity of grains
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent creates composite material structure by coating solid explosive particles with a phlegmatizer-emulsifier mixture, then embedding these coated particles in a fusible explosive matrix. This composite structure provides mechanical strength to the prefabricated grains - the solid explosive core maintains particle integrity while the surrounding fusible explosive and phlegmatizer layers provide binding and protection. During heating and stirring, this composite structure allows the grains to withstand mechanical stress while still melting and distributing uniformly.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes phase transitions to resolve the structural integrity requirement. The prefabricated grains are heated above the melting point of the fusible explosive, causing it to transition from solid to liquid state. This phase transition allows the grains to become pliable and adapt their shape without breaking, while the solid explosive particles maintain their integrity. The liquid fusible explosive flows around and binds the solid particles, forming a homogeneous mixture that can be easily cast.

Inventive Principle:
Principle #36Phase transitions

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach simplifies the casting process, reduces material complexity, and enables easier recycling by maintaining the structural integrity of the explosive grains, ensuring consistent composition and stability during remelting, thus facilitating the loading of ammunition bodies with reduced vulnerability.

Implementation Method 1

the grains are heated and stirred in a melting tank

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

heated and stirred in a melting tank under vacuum to ensure homogeneous emulsion

Methodology Applied
Scientific EffectEmulsion: Emulsion

Implementation Method 3

the grains are heated and stirred in a melting tank under vacuum

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP2318331B1Process for tasking an explosive material of reduced vulnerability and material employed in such a process
Publication Date: 2020.04.08 NEXTER MUNITIONS SA
  • EP2318331B1 patent drawingFigure 1~2d
  • EP2318331B1 patent drawingFigure 3a~3b

AI summary

The subject of the invention is a process for casting an explosive material of reduced vulnerability which combines, on the one hand, a solid phase comprising at least one solid explosive of reduced vulnerability, on the other hand, a fusionable phase which comprises at least one fusionable explosive, at least one phlegmatizer and at least one emulsifier. This process is characterized in that the explosive material is placed in the solid state in a vessel (4) fitted with heating means (8a, 8b) and provided with stirring means (5), the explosive material being placed in the vessel in the form of prefabricated particles having a size greater than the coarsest initial particle size of the materials of the solid phase that they enclose. The subject of the invention is also such a material in particle form.