Cellulose Ester Ignition Charge for Uniform Propellant Firing
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Solution Overview
Problem
Existing ignition charges for propellant charges in igniter tubes face challenges such as complex handling due to pyrotechnic risks, non-uniform ignition due to variable powder mass, and difficulties in disassembly, which are not adequately addressed by prior solutions like agglomerated powder tablets or flexible sheet-based compositions.
Innovation Solution
An ignition charge composed of cellulose ester-based support films with discontinuously distributed ignition powder patterns, obtained through molding or extrusion, which allows for controlled geometric patterns and reduced pyrotechnic risks, facilitating easy industrial production and modular energy distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If agglomerated powder tablets are used for ignition charge, then the ignition charge can be contained in a fuel tube, but the operation of filling the fuel tube is delicate and requires special tooling, and the evaporation time of the collodion solvent is long
Solution Approach 1:
The ignition charge is segmented into multiple individual tablets rather than a single agglomerated mass. Each tablet is independently formed and then placed into the fuel tube, simplifying the filling operation and eliminating the need for special tooling while maintaining reliable ignition through distributed combustion points
Solution Approach 2:
The ignition powder tablets are pre-formed outside the fuel tube using a simple mold, allowing the collodion solvent to evaporate before insertion. This preliminary formation eliminates the long evaporation time problem during the filling operation, as the tablets are already dry and stable when placed in the tube
2Adaptability or versatility
If the ignition charge occupies volume proportional to its mass, then the mass can be adjusted for ignition specifications, but the ignition of the propellant charge is not always uniform and synchronous along the channel's length
Solution Approach 1:
Different regions of the fuel tube receive different numbers of ignition tablets based on the specific ignition requirements. The tablets are distributed at different positions along the channel length, creating localized ignition zones that ensure uniform and synchronous propagation of the ignition wave across the entire propellant charge
Solution Approach 2:
Multiple identical ignition tablets are used instead of a single variable-mass charge. Each tablet has standardized dimensions and composition, providing consistent ignition characteristics. The number of tablets is varied to achieve different total ignition masses while maintaining uniformity through replication of the same reliable unit
3Ease of operation
If the ignition charge is extracted from the propellant tube for disposal, then the igniter tube can be removed, but direct contact with the agglomerated powder creates a pyrotechnic hazard
Solution Approach 1:
The ignition tablets are designed as disposable, non-recoverable components. After ignition, the tablets are consumed and transformed into combustion products. This eliminates the need for extraction and disposal operations, as the ignition charge naturally disappears after use, removing the pyrotechnic hazard entirely
Solution Approach 2:
The ignition function is extracted from a recoverable powder form and embedded into consumable tablet units that are intentionally designed to be destroyed during operation. This extraction of the ignition function into a disposable format eliminates the hazard of handling residual ignition material
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 cellulose ester-based ignition charge enables simple, safe, and efficient production, ensuring uniform ignition and easy disassembly, while reducing pyrotechnic risks and enhancing energy distribution, overcoming limitations of prior art.
Implementation Method 1
The firing tube consists of a combustible tube enclosing an ignition charge based on fast-burning propellant powder
Implementation Method 2
the evaporation time of the collodion solvent is long due to the confinement of the loaded collodion in the tube
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to an ignition charge consisting of a cellulose ester-based support film having, on one of its faces, an ignition charge distributed discontinuously in solid geometric volumetric patterns across multiple areas of the film, said ignition charge comprising at least an ignition powder and a cellulose ester. The invention also relates to a method for obtaining said ignition charge and to the use thereof in an igniter tube for ammunition.