Textile Insert for Combustible Ammunition Case Reinforcement
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Solution Overview
Problem
Combustible ammunition cases are fragile, leading to cracks or breakage during handling, which can result in the unsafe ejection of propellant powder, and existing reinforcement methods increase the case thickness and manufacturing costs.
Innovation Solution
A thin, stretchable textile insert made of knitwear, combining natural fiber yarns like cotton with polyurethane-blended yarns, is embedded within the case to absorb and bridge cracks, maintaining propellant containment without reinforcing the case's structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a large-meshed net made of cotton yarn is wrapped into the jacket wall in multiple layers to reinforce the case, then the strength and resistance to cracks are improved, but the thickness of the jacket wall increases and the manufacturing cost increases
Solution Approach 1:
The patent applies a thin film insert made of woven fabric with plasticized fiber material that can stretch and deform. This flexible thin film provides reinforcement while maintaining a thin profile, directly addressing the contradiction between strength and wall thickness by providing crack-bridging functionality without adding significant thickness.
Solution Approach 2:
The patent uses a composite material consisting of natural fibers (cotton, linen, hemp) combined with plasticizers to create a woven fabric insert with optimized mechanical properties. This composite structure provides both strength and flexibility, enabling the insert to bridge cracks effectively while remaining thin and cost-effective.
2Strength
If a large-meshed net made of cotton yarn is wrapped into the jacket wall in multiple layers to reinforce the case, then the strength and resistance to cracks are improved, but the manufacturing cost increases
Solution Approach 1:
The thin film insert made of woven fabric with plasticized fiber material provides reinforcement in a single layer rather than requiring multiple layers of traditional netting. This reduces manufacturing complexity and cost while maintaining or improving strength through the crack-bridging mechanism enabled by the film's flexibility and plasticization.
Solution Approach 2:
The patent changes the physical and chemical parameters of the fiber material by applying plasticizers, which fundamentally alters the mechanical properties of the woven fabric. This parameter change enables the material to stretch and bridge cracks dynamically, providing superior reinforcement at lower cost and simpler manufacturing compared to traditional multilayer netting.
3Volume of stationary object
If the jacket wall is made thinner to increase usable volume, then the volume for receiving propellant powder is improved, but the fragility and resistance to breakage worsen
Solution Approach 1:
The flexible thin film insert compensates for the reduced structural integrity of a thinner jacket wall by providing active crack-bridging functionality. When cracks form in the thin wall, the stretchable film stretches and holds the cracks together, preventing propellant leakage and maintaining reliability despite the reduced wall thickness.
Solution Approach 2:
The patent introduces a dynamic reinforcement mechanism where the plasticized fiber insert can deform, stretch, and adapt to cracking in the jacket wall. This dynamic response allows the thin-walled case to maintain reliability under stress, as the insert actively responds to and mitigates crack propagation rather than relying on static structural thickness.
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
The insert provides enhanced tear strength and stretchability to prevent propellant powder ejection through cracks, allowing for a thinner case wall and reduced manufacturing costs while ensuring safety and reliability.
Implementation Method 1
the natural fiber-plastic blended yarn has a content of natural fiber from 70% to 95%, especially between 70% and 95%, and/or a content of plastic fiber from 5% to 30%, especially between 5% to 30%. Because of its high stretchability, the plastic material according to one embodiment is polyurethane or includes polyurethane.
Data Source
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AI summary
The invention relates to an insert (5) made of a textile fabric for being received in a jacket wall of a cylindrical case (6) made of a combustible, felted fibrous material, wherein in particular the textile fabric includes one, several or a plurality of yarns which along a longitudinal direction (L) of the insert form a plurality of mesh rows (18) which each include a plurality of meshes (19, 20, 21) that extend in a circumferential direction (U) of the insert.