DE202014006882U1 - Active body with an active mass and a coating - Google Patents

Abstract

Active body, comprising an active compound (1) for pyrotechnical generation of a fog or for the provision of a pyrotechnic decoy target and a casing (2) for enclosing the active substance (1) and optionally an ignition set, wherein between the active substance (1) and the casing (2) at least one gap (3) is present, the gap (3) being such that it extends over at least 75% of an entire surface of the active material (1) and a flame extends through the entire gap (3) between the active material (1) and the envelope (2) can spread, the envelope (2) being such that it only after the flame has spread through the entire gap (3) under one in the envelope (2) by a reaction the active mass (1) and - if present - the ignition rate breaking up pressure

Description

The invention relates to an active body, comprising an active mass for pyrotechnic generation of a mist or for providing a pyrotechnic decoy target and a sheath for enclosing the active mass. Optionally, the active body may additionally comprise a firing kit.

From the GB 2 300 035 A a cartridge for an infrared light target is known. The cartridge contains a pyrotechnic active mass which emits infrared radiation (IR radiation) of a defined wavelength when burned, and means for firing the pyrotechnic active mass. The pyrotechnic active mass is formed by a plurality of blocks, which have different surfaces and / or different volumes. The cheek can ignite all blocks. The cartridge has retention means which hold the blocks together and which are capable of releasing the blocks almost simultaneously after ignition thereof. The cheek set may at least partially surround the blocks. The blocks may have furrows filled by the priming set. The cartridge may comprise a tubular sleeve made of aluminum or a heat-meltable plastic. The openings of the sleeve are each closed with a lid, which can be held in each case by an annular rim of the sleeve. The production of such an active body is relatively expensive.

The WO 02/48641 discloses an infrared light target having a housing, two pyrotechnic components housed therein, and an igniter for igniting the pyrotechnic components. The housing may consist of a unilaterally open cylindrical container which is closed at its open side with a closure which is held by an engaging in a groove of the closure brim of the housing. The two pyrotechnic components may each be wrapped in an aluminum foil and then wrapped together in another aluminum foil. After ignition of the pyrotechnic components, this film would melt very quickly and thus have no effect.

From the DE 10 2009 030 871 B4 an active body is known, which has a plurality of successively arranged or stacked flares as an active mass in particular for the production of decoys. The active body is enclosed by a plastic-like container. Between the inner wall of the container and the active body a Anzündübertragungsschicht is involved. The intermediate layer can consist of NC and / or RP granules. The object underlying this invention is to show an active body which has a residue combustible shell. To create the container, a plastic film, possibly also shrinkable, or a shrink tube can be used. On the front pages plastic discs or films are placed, which are glued or welded. This creates a spoiler lip, which favors the opening of the decoy during combustion. The container is hermetically sealed, thus ensuring protection against environmental influences.

• – die Strukturen an der Oberfläche Rillen und/oder Aufrauungen sind,
• – die Strukturen im Inneren durch Kanäle und/oder Hohlräume gebildet werden,
• – der Wirkmassenblock im Inneren Gas-/Temperaturbrücken zwischen den Kanälen und/oder Hohlräumen besitzt, die durch Schlitze, Perforationen und/oder Bohrungen gebildet werden und
• – in die Strukturen im Inneren fein strukturierte Materialien aus Wirkmassensubstanzen eingebracht sind, die gegenüber dem Wirkmassenblock ein deutlich erhöhtes Oberflächen-/Masseverhältnis aufweisen.

The DE 10 2004 047 231 B4 discloses a pyrotechnic active body for fake target generation, consisting of at least one pyrotechnic active mass block with specific structures on the surface and in the interior, wherein

• The structures on the surface are grooves and / or roughenings,
• The structures inside are formed by channels and / or cavities,
• - The active mass block has inside gas / temperature bridges between the channels and / or cavities, which are formed by slots, perforations and / or holes and
• - In the structures inside finely structured materials are incorporated from Wirkmassensubstanzen, which have a significantly increased surface / mass ratio compared to the effective mass block.

The active mass block may have a flow protection of a protective cap and a protective film. Through the cavities / channels in the interior of the active mass block, an inflow-protected initiation of the effective mass block in the interior is possible. In combination with, for example, metallic cover plates and protective films, this ensures that losses of the IR radiation at high flow velocities, such as occur when the active body is ejected from the aircraft, are avoided.

The object of the present invention is to specify an active body for the pyrotechnical generation of a mist or for the provision of a pyrotechnic decoy target, in which a reliable and rapid ignition of the effective mass contained therein can be achieved in a manner which is easy to implement.

The object is solved by the features of patent claim 1. Advantageous embodiments result from the features of claims 2 to 10.

According to the invention, an active body, comprising an active mass for pyrotechnic generation of a mist or for providing a pyrotechnic decoy target and a sheath for Inclusion of the active mass and optionally provided a set of firing. Either at least one gap is present between the active mass and the casing, or the casing is such that at least one gap forms between the active mass and the casing after ignition of the active mass and / or the firing rate, if such exists. The gap is such that it extends over at least 75%, in particular at least 80%, in particular at least 85%, in particular at least 90%, in particular at least 95%, in particular at least 98%, of the entire surface of the active mass and a flame passes through can spread the entire gap between the active mass and the envelope.

In order for the flame to propagate through the entire gap between the active mass and the cladding, the gap must have a geometry allowing for propagation, i. H. it must starting from an area at which the flame is to arise within the envelope at the beginning of the ignition of the active mass to at least 75%, in particular at least 80%, in particular at least 85%, in particular at least 90%, in particular at least 95%, in particular at least 98%, the entire surface of the active mass to be consistent.

The envelope is such that it does not break open until the flame has spread through the entire gap under a pressure built up in the envelope by a reaction of the active mass and, if present, the firing rate. This late break up is achieved by a suitable pressure and heat resistance of the envelope. This can be experimentally z. B. can be determined by measuring the time between ignition and breaking the envelope at variable thicknesses of the envelope. The time it takes for the flame to propagate through the entire gap can also be determined experimentally by firing on one side of the gap and with a high-resolution camera through a window in the envelope on the other side of the gap Slit or an indicator indicating the arrival of the flame is determined when the flame arrives on the other side of the gap.

The gap can be formed by various measures. For example, the active mass may have such unevenness that forms a gap between the envelope and the active mass when wrapping the active material with a sheath. For this it is sufficient, for example, that the active material is equipped with a rough surface. Alternatively, the active mass may also be shaped so that it forms at least one web on the surface of the active mass, which provides the gap between the active mass and the envelope. At least one web can also be provided by means of a cardboard strip, an elongate piece of wood or an inner wall of the wrapping. It is also possible that the gap is formed by a material which burns immediately by the propagating flame, thereby leaving a gap. Such a material may be, for example, nitrocellulose. The gap can also be formed by the fact that the wrap around the active mass expands due to the pressure forming during the burning of the firing set and / or the active mass and thereby stands out from the effective mass.

Due to the gap and the short-term resistance to the pressure forming within the envelope immediately after ignition, it is achieved that the flame formed by the firing set and / or the effective mass itself over at least a large part of the surface of the active mass, in particular over the entire Surface of the active mass, spread and can ignite the active mass over a large area before the wrapper breaks and releases the active mass thereby. As a result, the effect desired by igniting the active mass can be provided reliably and quickly. Due to the pressure increase occurring within the envelope in the short term, the burnup of the active mass and, if present within the envelope, of the firing rate are also accelerated. Furthermore, the active body according to the invention also makes it possible to use firing sets which are relatively slow-burning and therefore also more insensitive. These are not as dangerous during processing and are not as sensitive as fast-burning firing packs. The safety in the production of the active body according to the invention can be increased thereby.

If the active mass is an active mass for the pyrotechnical production of a mist, the envelope can be designed so that the pressure rise before breaking the envelope is not too high and does not occur too quickly. This can be achieved, for example, by selecting an envelope consisting of an elastic material. In the case of nebulizing effective masses, under certain circumstances, a large heating of the active mass may occur before the casing is broken up. This would cause the fog to be very hot and rise in the air as a smoke candle, rather than forming a near-surface fog.

The active material may be formed as a powder or granules, as a solid block or as a stack of smaller blocks of active substance, tablets or platelets. It can be one, in particular under Pressure, cast, extruded or pressed active mass act.

The Anfeuerungssatz for the active mass for pyrotechnic generation of a mist may be red phosphorus or black powder. In the Anfeuerungssatz for an explosive material to provide a pyrotechnic decoy may be MTV, ie a mixture of magnesium, Teflon ^® (polytetrafluoroethylene) and a performance elastomers marketed by DuPont under the name Viton ^® fluoroelastomer act when with him the Sham target is a so-called blackbody target. For a spectrally radiating decay when burned z. B. a mixture of ammonium perchlorate and polybutadiene as Anfeuerungssatz.

In one embodiment of the active body according to the invention, the enclosure is designed such that it encloses the active mass hermetically and / or breaks open when a defined bursting pressure is reached. Due to the hermetic enclosure, the active compound can be protected from moisture, air, dust or even mechanical damage. How the envelope must be designed in order to break up when the defined bursting pressure has been reached can be easily determined experimentally. For this purpose, the envelope can be pressurized, for example by means of air, without active mass contained therein, the pressure being steadily increased and measured. If the casing breaks open before reaching the defined bursting pressure, the wall thickness of the casing, for example, can be increased until it breaks open only when the defined bursting pressure is reached. If it breaks at a pressure above the defined bursting pressure, z. B. the wall thickness of the enclosure are reduced so much that it breaks when reaching the defined bursting pressure.

In the case of the active body according to the invention, the covering can be produced very simply and effectively with little labor and material expenditure. By choosing the material of the wrapper and by choosing the material thickness, the pressure that the wrapper can withstand can be adjusted. For example, this is very easily possible in the provision of the wrapping by wrapping by choosing the number of layers of the winding, d. H. increased, decreased or maintained. By a relatively long residence time of the active material in the enclosure before the enclosure breaks up, an ignition of the active material can be ensured over the entire or almost entire surface of the active mass. The wrapping can be made so easily that no devices, especially prefabricated parts or machines are needed.

For example, at least a portion of the wrapper can be used as a wrap of adhesive tape, paper, a non-aluminum metal foil, a fibrous damping material, such as a metal foil. As glass wool or rock wool, coated metal foil, as z. B. is used for thermal insulation, plastic film, fabric, glass fabric, felt, nonwoven, twine, yarn, a strip-shaped material and / or a fiber comprising and optionally treated with a binder material may be formed. By the fibrous insulation material can be provided in a very simple manner reliably the gap between the active mass and the enclosure. The gap in the sense of the invention is a space that can be penetrated by the flame. The room can be empty, d. H. only be filled with air or another gas. He does not need to be completely empty. A space filled with fiber material, which can still be penetrated by the flame, thus represents a gap in the context of the invention.

The plastic film is relatively heat-resistant in one embodiment of the device according to the invention, ie it maintains a temperature of at least 150 ° C, in particular at least 170 ° C, in particular at least 190 ° C, in particular at least 210 ° C, in particular at least 230 ° C, in particular at least 250th ° C, in particular at least 270 ° C, stood. The plastic may be, for example, polyetheretherketone (PEEK), polyetherketone (PEK), thermoplastic polyimide (TPI), polysulfone (PSU), polyethersulfone (PES), polyphenylene sulfone (PPSU), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene (ETFE), a fluororubber such. As the Viton ^® sold by DuPont Performance Elastomers, or any other fluorine-containing plastic, in particular a fluoroelastomer act.

The binder can be a paint, a synthetic resin, tar, pitch or an adhesive. The treatment with the binder can be carried out, for example, by brushing, impregnating, dipping, spraying or another coating method.

The winding of adhesive tape is very easy to produce. For their production, it requires no special tools. The gap can be made very simply by the fact that the Anfeuerungssatz is applied in the form of granules or a powder on the adhesive of the adhesive tape. The particles of the granules or powder remain adhered to the adhesive. The active mass can then be wrapped directly with the tape, so that the Anfeuerrungssatz between active mass and adhesive tape remains and forms a gap between the active mass and the winding there. The tape can be wound in parallel, transversely or spirally in relation to a longitudinal axis of the active mass. The pressure which the casing thus formed withstands can be determined simply by the choice of the type of adhesive tape and / or the number of overlapping windings of the adhesive tape.

A very simple way to provide the gap in the provision of the envelope in the form of a winding is to place the Anfeuerungssatz in a separate form, for example in the form of a fuse or wrapped in paper on the active mass and then to wrap together with the active mass.

The non-aluminum metal foil may, for example, be a metal foil of tantalum, tungsten, copper, iron or an alloy containing at least one of these metals, in particular brass. Making the sheath as a winding of the non-aluminum metal foil or the metal foil coated with the fibrous insulating material has the advantage that metal foil for winding is easy to deform and self-sustains after winding. The winding is therefore easy to do by hand. A special device is not required. After winding, the metal foil can be closed at open ends simply by crimping. An aluminum foil has the disadvantage that it melts very quickly on burning of the active material and the winding is thereby rapidly destroyed, so that if necessary for a quick and complete ignition of the active mass no sufficient pressure within the envelope. The problem is less pronounced if the metal foil coated with fibrous insulating material consists of aluminum, because the aluminum is thermally shielded from the burning active mass by the insulating material. The metal foil coated with the fibrous insulating material may therefore be an aluminum foil.

In order to get the gasket formed by the metal foil reliably gas-tight and thereby obtain a higher pressure rise immediately after ignition, the metal foil, for. B. with an adhesive tape or adhesive sealed.

Due to the generally higher heat resistance of a metal foil over a plastic film or non-metal adhesive tape and the higher mechanical strength of the metal foil, the pressure achievable by an envelope formed from metal foil is relatively high prior to rupture of the envelope. As a result, a very rapid increase in pressure and thereby also a very reliable ignition of the entire active mass can be achieved within the envelope at the beginning of the burnup of the active mass.

Another advantage of a metal foil is that it can reflect the heat generated during firing on the active mass surface. Also, the ignition can be accelerated.

If, on the other hand, a rapid tearing of the covering without an excessively high pressure increase is desired, the metal foil may be made of magnesium, for example. Magnesium foil in the case of an active mass for providing a pyrotechnic decoy target has the advantage that it co-burns when burned the active mass and thereby contributes to the radiant power. In the case of an active mass for the pyrotechnical generation of a mist, the use of a film of zinc may be advantageous, since zinc additionally generates a pyrotechnic mist upon combustion.

The provision of the sheath as a winding of a plastic, in particular a heat-resistant plastic, has the advantage that the pressure at which the sheath breaks open and releases the active material, by the melting or decomposition point of the plastic and possibly its elasticity and thus can be well determined by the choice of plastic. Such a coating may be advantageous if, although a complete ignition of the active mass after ignition should take place, but the onset of the action of the active body should be relatively slow, d. H. the so-called rise time is relatively long. This is z. Example, in a reactive mass for the pyrotechnic generation of a mist of the case, in the combustion, the emergence of a rising rapidly in the air mist candle is to be avoided.

Another advantage of a winding made of plastic film is that a Anfeuerungssatz can be arranged outside the winding of plastic film directly to the winding. As a result, the production of the active body can be considerably simplified because attaching the Anfeuerungssatzes directly on the active mass is often time consuming and it must always be taken precautions to avoid accidental ignition of the Anfeuerungssatzes. These precautions can be omitted if the active material is provided without Auffeungsungssatz with a winding of plastic film. In addition, often occurring problems of chemical incompatibility of the Anfeuerungssatzes be avoided with the effective mass. It is thereby even possible to combine completely incompatible combinations of active material and Anfeuerungssatz in a body of action.

Another advantage of the winding made of plastic film is that the plastic can be combustible, so that after firing the active material and burning of the plastic film little or no remains of the plastic film remain. The energy from the combustion of the plastic can also be used to increase, for example, the radiation power during combustion of an active mass to provide a pyrotechnic decoy target.

The advantage of a paper wrap is that it is particularly easy to wrap and handle, and on the other hand is very inexpensive and easily available. Furthermore, a paper winding has the advantage that it is biodegradable. If after burning of the active body paper should remain in nature, this can easily biodegrade. The degradability is also facilitated by the fact that paper breaks brittle, so that after bursting the envelope many small and distributed over a large area pieces remain.

When activating the active mass paper has the advantage that it acts thermally insulating. As a result, the firing of the active mass is accelerated because the heat generated by the Anfeuerungssatz can flow only relatively slowly from the active body. In the short term, paper is very heat resistant and retains its strength even in the heat. The strength is lost only when the paper burns or charred.

Another manufacturing advantage is that paper very well, for. B. can be glued with a water-based adhesive without organic solvent. As a result, no organic solvent vapors are released in the production, so that appropriate measures to protect the entrusted with the production of workers before such solvent vapors can be omitted.

The bursting pressure of a paper coil can be determined by the choice of paper type and the number of layers of the coil.

The winding of fabric, glass fabric, felt, nonwoven, twine, yarn, a strip-like material and / or a material comprising fibers, which is optionally treated with a binder, can be designed to be gas-permeable. Thus, the adjusting itself to a start within the active body pressure, z. B. by the fiber density in the material, the layer thickness or the number of layers of the winding or the density of the winding can be adjusted. In addition, the permeability of the enclosure is advantageous because it can escape through the enclosure during combustion of an active mass for pyrotechnic generation of a mist through the enclosure and blow at an active mass to provide a pyrotechnic decoy, the resulting during combustion of the active mass flame already through the enclosure to the outside can and thus is already visible before bursting the envelope. The effect of the active body thus occurs a little earlier. The gas-permeable fibrous material may also retain particles, such as incandescent particles from the flame or a residual slag, if it is such that it is not destroyed by the burnup of the active mass.

If it is an elastic winding, the pressure drop when bursting the envelope is not so strong. This is advantageous in the case of active compositions in which a large pressure drop can lead to extinction of the active material.

If the sheath is formed as a winding of string, yarn or a strip-like material, the active body can thereby be compressed from the outside and thereby its stability to vibration and shocks are increased.

By treating the winding with a binder, after the solidification or hardening of the binder, the formation of a, in particular hermetically sealed, sheath around the active mass can be effected.

To provide the gap between the active mass and the winding can between the active mass and the winding webs, z. B. of wood or cardboard, as spacers are wrapped with.

A winding treated with a binder can also be separated from the active mass by winding around a mold, e.g. B. made of wood, metal or clay. The active material can then be used after the solidification or hardening of the binder in the enclosure formed thereby.

The advantage of providing the sheath as a winding is that even complex outer contours of the active material can be easily enveloped. There are no restrictions on the shape of the active mass. With the usual in the prior art containers for introducing active material, the effective mass is limited to the geometry of the container. A winding can be adapted to any shape.

The treatment of the winding with the binder has over the direct treatment of the active material with the binder the advantage that the winding in a simple way, the provision of the gap between the active mass and the envelope allowed. In a direct coating of the active material with the binder would normally remain no gap between the sheath and the active mass. An exception is only the direct binder coating such an active mass, which contracts after curing of the binder, thereby forming the gap between the active material and the envelope formed by the cured binder.

The wrappers disclosed in this patent application may be combined with one another in any desired manner. For example, the winding may consist of at least one layer of paper, which is overlapped or at least partially non-overlapping wrapped with adhesive tape. Where the wrapping with tape is non-overlapping and possibly even the paper is exposed, a weak point is formed which allows a defined bursting of the wrapping at this point of weakness. The strength of the weak point can be determined by the strength of the paper and / or the number of layers of paper used for the winding. The adhesive tape may be a textile-reinforced or fiber-reinforced, possibly with metal, in particular aluminum, coated adhesive tape, a metal or metal strip-containing adhesive tape or an adhesive tape made of a metal foil coated with an adhesive. The combined winding of paper and adhesive tape allows the advantages of paper wrapping and winding to be combined with adhesive tape.

If the active material is wrapped directly with the adhesive tape, the direct contact of the adhesive surface with the effective mass, at locations where there is no gap between active material and sheath, cause an inhibition of the ignitability of the active mass, so that the active mass at these points altogether can not be ignited or only delayed. This is particularly problematic in the case of active compositions for providing a pyrotechnic decoy target. Such inhibition of the ignitability does not occur when the active material is first wrapped with a wrap of paper and the paper is then wrapped with the tape. Small bumps on the active mass cause paper to leave a gap between the active mass and the cladding.

A further advantage of a wrapping comprising paper and adhesive tape is that such a casing is relatively resistant to heat acting on the active body from the outside, because paper has a thermally insulating effect. The thermal insulation effect of paper is greater the more layers the paper wrapper comprises. Particularly advantageous is the combination of a metal foil comprising adhesive tape on a paper winding. Without the paper winding, such an adhesive tape would conduct heat acting on outside from the outside very well, so that it could ignite undesirably. A winding of paper alone can burn out locally when exposed to high heat, so that it can also cause unwanted ignition of the active mass. However, if the envelope initially comprises at least one layer of paper on top and then a coil of adhesive tape comprising a metal foil, local and short-term heating of the active body will not cause ignition since the paper is isolated long enough for the heat to dissipate through the metal strip and is distributed thereby before the active material reaches its ignition temperature locally. As a result, the peak temperature reached locally on the active mass surface is significantly reduced, so that inadvertent ignition of the active mass can be avoided.

Compared to a pure winding of adhesive tape, the combined winding of paper and adhesive tape also has the advantage that the winding is facilitated because the paper is somewhat stiff and thus keeps the wound active mass in shape. Many textile tapes, d. H. Adhesive tapes comprising a textile coated with an adhesive, are unable to give the active material during winding a shape or to keep this shape.

In one embodiment of the invention, the envelope comprises a container made of plastic, cardboard, paper, a material comprising fibers or of metal. The envelope may also consist of a container made of plastic, cardboard, paper, a material comprising fibers or metal. The plastic may be an elastic tube, a shrink tube or a bottle, for. B. of PET (polyethylene terephthalate) act. A heat-shrinkable tube is a tube which contracts when heated and adapts itself to the shape of the active material or active mass arranged in its interior with spacers for forming the gap. The cardboard container can be, for example, a cardboard tube with lids arranged on the open sides. At least one of the lids or one of the connections of the cardboard tube with at least one of the lids can provide a predetermined breaking point with a defined bursting pressure. The fiber-comprising material may be a fiber-reinforced plastic, for example glass fiber or carbon fiber reinforced epoxy resin. The container made of metal may be, for example, a conventional can, as z. B. is also used as a tin. In the container made of metal, the ignition can take place through a small opening provided in the container.

A plastic container in the form of a bottle can be produced very economically with tight tolerances. A commonly used for bottles for holding carbonated liquids material, eg. PET, is well suited for making bottles which can withstand relatively high pressure before bursting. By using such a container, a particularly short rise time can be achieved. A rise time is understood to mean the time between the ignition of the effective mass and the occurrence of the desired effect of the active mass. In the desired effect of the active material may be, for. For example, the generation of a mist in the mist active mass or the generation of an IR radiation in the decoy effective material.

The production of an active body according to the invention, in which the envelope comprises a container made of plastic in the form of a bottle, is particularly simple, in particular if the bottle is equipped with a lid designed as a quick-acting closure. A plastic bottle is somewhat flexible, but very dimensionally stable, so that it can better protect the active mass against shock and friction than, for example, a metal can, which is permanently deformed by a blow.

The container made of plastic or metal can also be designed so that there is a thermal expansion of the active mass, for. B. by temperature fluctuations during storage, can compensate without changing all its outer dimensions. For this purpose, for example, a metal can or a plastic bottle having an inwardly curved bottom. With an expansion of the active mass then the soil bulges slightly outwards, without changing the diameter of the plastic bottle or metal can or their respective total length. As a result, the active body according to the invention in an object, for. B. in a fog cartridge, be installed without this object must be designed so that it tolerates an expansion of the active mass or compensates. Thereby, the structure of such objects can be simplified.

In addition, a plastic bottle can be easily made so that it has a predetermined breaking point, via which the bursting pressure of the envelope can be adjusted. Furthermore, a plastic bottle is well suited to complete the active material hermetically sealed, so that no undesired interactions of the active material with the environment and in particular with moisture from the environment occur.

A hermetically sealed wrapper may also be provided by a metal can, such as a can. As in the case of an envelope made of a plastic bottle, the wrapping in the form of a metal can also offers the advantage of easy handling of the active mass. Another advantage of a container made of metal is that the active material can be ignited through a wall of the container through, without the container must have an opening to it. For this purpose, the wall of the container z. B. by means of a Anfeuerungssatzes or a laser beam to be heated from the outside. Since it takes some time until the wall of the container reaches the ignition temperature of the active mass within the container, such a container can be used selectively as an element for delaying the ignition. This can be advantageous, in particular, in the case of active bodies which contain an active mass for the pyrotechnical generation of a mist, because such active bodies are often required to reach a certain position only after being fired before the formation of the mist commences. Due to its pressure resistance, a metal can also contributes well to accelerating the firing of the active mass or a shortening of the rise time.

An elastic container, in particular made of plastic, such as. As a sealed rubber hose, a plastic bag, a, especially specially folded, plastic bag or a container made of an elastic potting compound, offers the advantage that thereby the pressure within the enclosure after ignition of the active material can be regulated. After ignition of the active material, gases develop and expand the elastic container, the pressure remaining approximately constant until the container bursts. Bursting is all the more delayed, the more elastic the container is, d. H. the more it can expand before it bursts. This leaves within the container for a relatively long time a hot environment, which favors the complete ignition of the active material contained in the container and the use of relatively less sensitive, d. H. difficult to ignite, effective masses possible.

Furthermore, such an elastic covering advantageous for active body, which contain active materials that can go out at a strong pressure drop after their ignition, as z. B. is often the case with active compositions for generating a spectrally radiating decoy. By an elastic container, this can be avoided. If the container is still permeable to IR radiation at the same time, the rise time of a IR radiation emitting decoy is not reduced compared to the rise time in the provision of a non-elastic container, because the radiation is emitted to the outside before bursting of the container.

Another advantage of a container made of an elastic material is that As a result, shocks and vibrations acting on the active body are damped, so that the active body is more resistant to external stresses. The sensitivity to inadvertent ignition of the active mass by external influences such. B. shock, can be reduced.

In one embodiment, the container is such that a space enclosed by the container under pressure can increase by at least 20% of its original volume before the container bursts. This can be z. B. by an elasticity of the container forming plastic or by a special folding, z. B. a concertina folding, the container, z. As a metal can, can be achieved.

A cardboard or paper container enables fast, easy and safe production because cardboard and paper have an antistatic effect, so that friction can not cause electrical discharges, which can unintentionally ignite the active material. Furthermore, paper and cardboard very effectively absorb impacts and friction, so that there is little or no mechanical load on the active material in the event of mechanical loading of the active body and the sensitivity of the active body to external influences is thereby reduced. With a predetermined breaking point or an end cap, such as a lid on a cardboard tube, the bursting pressure can be easily adjusted. In the case of a container comprising a lid, the term bursting pressure also means the pressure at which the lid detaches from the rest of the container without destroying the container.

The remaining after a reaction of the active mass remains of a container made of cardboard or paper are biodegradable and pollute the environment at best low. In addition, cardboard and paper are almost everywhere good and inexpensive to obtain. Furthermore, cardboard and paper are relatively heat resistant in the short term. For example, cardboard and paper can withstand the heat generated during the reaction of the active material longer than many plastics. Due to the associated pressure resistance, the ignition of the active material is favored. Another advantage is that cardboard and paper can be broken up into a large number of small pieces when bursting. As a result, the active mass contained is released more evenly than for example from a container made of plastic, which breaks only at one point and remains essentially in one piece.

The container can also be designed so that it has spacers for providing the gap on its inner side facing the active mass. For this purpose, the inner wall of the container, for example, ribs or webs have.

In one embodiment of the active body according to the invention, the sheath is completely or partially coated with a coating. Alternatively, the sheath can also be formed by a coating applied to the active material. The coating may, for. B. be applied to the above winding. The coating may consist of a potting compound or a coating. The coating is generally formed from a fusible or curable material. If the coating is formed by a coating applied to the active material, a release agent is generally applied to the active material in order to provide the gap, so that the coating is applied only indirectly to the active material. The release agent may be, for example, a powder, for. Flour, act. It may also be a material which after curing of the coating, for. B. by drying, its volume is reduced, so that thereafter the gap remains. Such a material is for example a gel.

The application of the coating may, for. B. by immersion in a potting compound. The application of the coating on the envelope or the release agent has the advantage that the potting compound does not come into direct contact with the active mass and thereby problems that may arise on the adhesion of the potting compound to the active mass, are avoided. Such a problem may be, for example, an inhibition of the ignitability of the active mass. At the same time, however, the envelope can be hermetically sealed, which z. B. is not possible with a mere winding of paper. Also can be reliably and easily ensured by coating the coating with the coating, the gap between the envelope and the active body. Thereby, the advantage of simply providing a hermetic seal of the active mass by means of a coating with the advantage of simply providing a gap between the sheath and the active mass can be combined.

The active mass may be an active mass for providing a pyrotechnic decoy target which emits during the burnup of IR radiation, wherein the cladding is permeable at least in places to IR radiation. As a result, the IR radiation produced during the combustion of the active mass can be released through the enclosure already before the casing bursts, in order to produce the desired illusion effect. For this purpose, the envelope z. B. of polyethylene terephthalate (PET) exist. For example, it may be at the wrap around to trade a PET bottle. PET is permeable to IR radiation.

The envelope may also be configured as an IR filter in that the envelope comprises or consists of a plastic container which is permeable only to IR radiation, in particular IR radiation of a defined wavelength, and impermeable to other radiation. This is particularly advantageous if the decoy target is a decoupling beam which emits bispectrally during burnup, in which the proportion of short-wave radiation in the total radiation is to be kept as low as possible. Since efficient Anfeuerungssätze burn off with very high temperature, they often set a relatively high proportion of blackbody radiation with a high proportion of short-wave IR radiation free. In such a case, it is very advantageous if the enclosure can filter the radiation during the short time that the firing charge is burning so that little or no black body radiation will leak out. Then very quickly abreagierende and thereby a large heat-generating Anfeuerungssätze can be used without affecting the spectral ratio of a spectrally emitting decay when glowing too negative or negative at all.

In one embodiment of the active body according to the invention, the sheath comprises a pyrotechnic or energetic material or the sheath consists of a pyrotechnic or energetic material. For the purposes of the invention, an energetic material is a material which can burn off after ignition of the active mass simultaneously with the active material or thereafter with the release of energy after it has been ignited by the burning active mass or the Anfeuerrungssatz. Such an energetic material is, for example, nitrocellulose. A pyrotechnic material is understood to mean a mixture of an oxidizing agent and a fuel, optionally together with a binder, which burns off after ignition by the active mass or the firing charge with the release of energy. The envelope of pyrotechnic or energetic material burns after their ignition and can thereby contribute to the desired effect of the active mass without residues of the envelope remain. Furthermore, such sheaths can contribute to the firing of the active mass. In particular, in the case of active bodies which comprise an active mass for providing a pyrotechnic decoy which spectrally radiates when burned, a cladding made of nitrocellulose is advantageous, since it contributes to the radiation power during its burning without impairing the spectral ratio. The energetic material is generally a polymer. The pyrotechnic material may be the same material that constitutes the active material, which optionally additionally contains a binder, or wherein the binder contained in the active material has been replaced by another binder. As a result, no space is needed for a material that does not contribute to the desired effect, because the envelope itself also contributes to the effect.

In a further embodiment of the active body according to the invention at least one spacer for forming the at least one gap is disposed on the outside of the active mass, the enclosure comprises a shrink tube and the gap is filled with the Anfeuerungssatz. The spacer may be a web, for example of wood, or of a polymer such as nitrocellulose or polyethylene.

Such an active body is relatively easy to produce. By providing the spacer and the otherwise close concern of the shrink tube to the active mass of the Anfeuungssatz remains, even under mechanical stress and vibration, in its original position. The Anfeuerungssatz is thereby fast, safe and easy, also automated, to install. The fact that the Anfeuerungssatz can not accumulate by vibration, for example, at one end of the active mass, but is held in place, a reliable ignition of the active mass is achieved. If the shrink tube is designed to be elastic, in addition to the above-mentioned advantages of an elastic envelope.

The invention will be explained in more detail with reference to an embodiment. Show it:

1 a schematic representation of an active body according to the invention and

2 a photographic representation of an envelope of a body of the invention after ignition and release of the active material.

1 shows the active mass 1 which of a serving 2 is surrounded. It is between the envelope 2 and the active mass 1 , For example, by spacers, not shown here, z. B. in the form of webs, a gap 3 provided in which, during and after ignition of the active material 1 build up a pressure and through which a flame can propagate and spread. On the surface of the active mass 1 is applied here not shown Anfeuerungssatz. The Anfeuerungssatz can be applied as a coating on the surface, on the active mass 1 glued or loose in the gap 3 be arranged. Through the opening 4 in the serving 2 the firing set can be ignited. Alternative to the above arrangements shown, the Anfeuerungssatz also in the opening 4 be arranged and ignited from the outside and thereby the active mass 1 cheer. By igniting the ignition set and the effective mass 1 the pressure in the gap increases 3 and the forming flame spreads through the gap 3 off and surrounds the active mass 1 on their entire surface. This will be the effective mass 1 Fired significantly faster over the entire surface and the burning rate of the active mass 1 is significantly higher than in a corresponding active body without the gap 3 , Once the serving 2 stops the pressure stops breaking this at any or a predetermined breaking point, not shown here, leaves the pressure escape and sets the effective mass 1 free. By this arrangement it is achieved that the active mass 1 at the time of their release burns on their entire or at least a large part of their surface.

2 shows an embodiment of the active body according to the invention. This was the effective mass 1 first wrapped with a paper and closed at the side surfaces. Subsequently, a wrapping with a fiber-reinforced coated with aluminum tape, which was also sealed at the sides. 2 shows the state of the enclosure 2 after ignition of the active material 1 and their release after bursting of the envelope 2 , It turns out that the envelope has been damaged only relatively weak on its inside and is not charred, for example.

LIST OF REFERENCE NUMBERS

1

effective mass

2

wrapping

3

gap

4

opening

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• GB 2300035 A [0002]
• WO 02/48641 [0003]
• DE 102009030871 B4 [0004]
• DE 102004047231 B4 [0005]

Claims (10)

Active body comprising an active mass ( 1 ) for the pyrotechnical production of a mist or for the provision of a pyrotechnic decoy and an envelope ( 2 ) to include the active material ( 1 ) and optionally an initiation set, wherein between the active mass ( 1 ) and the envelope ( 2 ) at least one gap ( 3 ), the gap ( 3 ) is such that it covers at least 75% of an entire surface of the active material ( 1 ) and a flame extends through the entire gap ( 3 ) between the active material ( 1 ) and the envelope ( 2 ), the envelope ( 2 ) is such that only after the flame has passed through the entire gap ( 3 ) has spread under one in the envelope ( 2 ) by a reaction of the active material ( 1 ) and - if present - the Anfeuerungssatzes building pressure builds up. The active body according to claim 1, wherein the sheath ( 2 ) is such that it is the effective mass ( 1 ) hermetically encloses and / or breaks open upon reaching a defined bursting pressure. The active body according to claim 1 or 2, wherein at least a part of the envelope ( 2 ) as a wrap of adhesive tape, paper, a non-aluminum metal foil, a metal foil coated with a fibrous damping material, plastic film, fabric, glass cloth, felt, nonwoven, cord, yarn, strip material and / or fiber, and optionally with a binder-treated material is formed. The active body according to claim 3, wherein the winding consists of at least one layer of paper which is wrapped in overlapping or at least in places non-overlapping with adhesive tape. Active body according to one of the preceding claims, wherein the sheath ( 2 ) comprises or consists of a container made of plastic, cardboard, paper, a material comprising fibers or of metal. The active body according to claim 5, wherein the container is such that a space enclosed by the container under pressure can increase by at least 20% of its original volume before the container bursts. Active body according to one of the preceding claims, wherein the sheath ( 2 ) is completely or partially coated with a coating or the coating ( 2 ) of one on the active mass ( 1 ) applied coating is formed. Active body according to one of the preceding claims, wherein the active material ( 1 ) an active mass ( 1 ) for providing an infrared radiation emitting pyrotechnic decoy target upon burnup, the cladding ( 2 ) is at least partially permeable to infrared radiation. Active body according to one of the preceding claims, wherein the sheath ( 2 ) comprises or consists of a pyrotechnic or energetic material. Active body according to one of the preceding claims, wherein on the outside of the active mass ( 1 ) at least one spacer to form the at least one gap ( 3 ), the wrapping ( 2 ) comprises a shrink tube and the gap ( 3 ) is filled with the Anfeuerungssatz.

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