Cast Explosive Composition Using Microencapsulated Cross-Linking Reagent
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Solution Overview
Problem
Conventional casting techniques for polymer-bonded explosives often result in inhomogeneous cross-linking and air bubbles, leading to reduced performance and increased sensitivity to impact, friction, and heat, which can cause inadvertent initiation.
Innovation Solution
A pre-cure castable explosive composition is developed, featuring a microencapsulated cross-linking reagent that allows for controlled curing, ensuring uniform distribution and delayed reaction initiation, reducing the risk of premature solidification and improving stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional casting techniques are used with immediate cross-linking, then the explosive composition sets quickly, but inhomogeneous cross-linking and air bubbles occur, reducing performance and increasing sensitivity
Solution Approach 1:
The cross-linking reagent is pre-encapsulated in microcapsules and uniformly distributed throughout the polymer binder before casting. This preliminary encapsulation action prevents premature cross-linking during mixing and pouring, allowing the composition to be cast in a homogeneous state. The cross-linking then occurs uniformly after casting when the microcapsules are activated, eliminating the inhomogeneous cross-linking and air bubble problems associated with immediate cross-linking.
Solution Approach 2:
Microcapsules serve as an intermediary carrier for the cross-linking reagent. Instead of adding the cross-linking reagent directly to the mixture, it is encapsulated in microcapsules that protect it from premature reaction. These microcapsules distribute the reagent uniformly throughout the composition and control its release timing, enabling homogeneous cross-linking throughout the entire volume of the explosive composition.
2Productivity
If cross-linking reagent is added directly to the mixture, then cross-linking occurs immediately, but the material solidifies too quickly, causing rejection of material and disposal costs
Solution Approach 1:
The cross-linking reagent is pre-encapsulated in microcapsules that remain stable during mixing and pouring operations. This preliminary encapsulation extends the pot life of the composition, allowing sufficient time for complete filling of munitions and moulds before cross-linking begins. The microcapsules prevent premature solidification, ensuring all material can be processed and filled without waste.
Solution Approach 2:
The physical state and reactivity of the cross-linking reagent are changed by encapsulating it in microcapsules. This encapsulation modifies the release characteristics of the reagent, transforming it from an immediately reactive state to a controlled-release state. The parameter change in reagent delivery timing extends the working time window for processing and filling operations.
3Temperature
If high melting point binders are used for melt casting, then high temperature processing is achieved, but processing hazards increase
Solution Approach 1:
The invention changes the processing parameters by using a two-stage process: first mixing and pouring at low temperatures with the polymer binder in its original state, then activating cross-linking at moderate temperatures after casting. This avoids the need for high-temperature melt processing, significantly reducing processing hazards while achieving the desired final product properties through controlled cross-linking.
Solution Approach 2:
The microcapsules act as an intermediary that enables low-temperature processing. By encapsulating the cross-linking reagent, the system allows mixing and pouring to occur at safe, low temperatures. The cross-linking reaction is then activated at moderate temperatures after casting, achieving the desired material properties without exposing operators to high-temperature hazards.
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 enhances the stability and reduces sensitivity to stimuli, allowing for the production of high-quality, homogeneous polymer-bonded explosives with improved safety and performance by controlling the curing process and minimizing exposure to hazardous reagents.
Implementation Method 1
a microencapsulated cross linking reagent, which comprises a cross linking reagent encapsulated in a microcapsule
Implementation Method 2
Upon addition, an immediate polymerisation reaction occurs, leading to the formation of an inhomogeneous crosslinked rubber matrix
Data Source
AI summary
The invention relates to a cast explosive composition, particularly to a pre-cure castable explosive composition comprising an explosive material, a polymerisable binder, a microencapsulated cross linking reagent, said microencapsulated cross linking reagent, comprising a cross linking agent encapsulated in a microcapsule.