EP0758479A1

EP0758479A1 - Protective device for shielding people from high-frequency electromagnetic fields

Info

Publication number: EP0758479A1
Application number: EP95917951A
Authority: EP
Inventors: Manfred Hellwig; Thomas BRÜHL; Rudolf Jun. Schilk
Original assignee: Ploucquet C F GmbH and Co
Current assignee: texplorer GmbH
Priority date: 1994-05-02
Filing date: 1995-04-25
Publication date: 1997-02-19
Anticipated expiration: 2015-04-25
Also published as: DE59502180D1; DE4415372C2; ATE166175T1; WO1995030229A1; DE4415372A1; AU2407495A; EP0758479B1

Abstract

A protective device is disclosed for shielding people from high-frequency electromagnetic fields and/or to provide camouflage against heat-imaging systems. The proposed device is designed as a suit which surrounds an individual and is made from a carrier material which is provided with shielding fibres or yarns or additional shielding components. The base material used to make the carrier material, or the carrier material itself, contains polyamide fibres or polyamide yarns (1) which are given an all-over silver coating layer (2). A polymer layer (3) is applied to the silver coating layer on the outside and seals the silver-metallized fibres or yarns.

Description

Protective device for people for shielding against high-frequency electromagnetic fields

The invention relates to a protective device for people for shielding against high-frequency electromagnetic fields and / or for camouflaging against thermal imaging devices with a carrier material in the form of a suit, which is provided with shielding fibers, yarns or additional shielding components.

As is well known, high frequency waves, e.g. Microwaves, higher power increasingly used for commercial and military purposes. This affects e.g. Microwaves in telecommunications, in the navigation of airplanes and ships, the heating of food, the drying of goods and the like.

In addition, transmitters operating in the high-frequency range, especially in the close range, can endanger persons through electromagnetic fields with a higher power density. This affects e.g. People who have to operate or maintain devices that transmit or work in the mega and gigahertz range and who move in their electromagnetic fields for this purpose. This affects e.g. also the maintenance and / or repair of antenna systems.

Through the above-mentioned protective device is to be prevented ver¬ since _/ 5 cause such high frequency and energie¬ rich radiation damage in humans. The effect of the electromagnetic high-frequency waves on the cell structure is essentially a heat effect, also called a thermal effect. If heat exposure due to radiation is exceeded, which the human body normally regulation of sweat / 3, it can lead to harmful effects of heat by the electromagnetic waves on the organism.

Ionizing rays in a frequency spectrum above the light range, for example X-rays or gamma rays, are so high in energy that they can cause damage in the molecules of the cell tissue. In animal experiments, for example, biologists and researchers found that with poorly perfused organs, the harmful radiation density is already 5 mW / cm ² . It was found that a power flux density of 10 mW / cm ² when absorbed in humans already gives a heating power of 1 W / kg comparable to the basic metabolism.

For example, Backing materials in the form of suits, which are designed as a textile net with silver and a subsequent rubber coating. Nets with embedded metal foils are also known.

In general, attempts have always been made to weave in metal fibers or metal wires, e.g. VA short fibers, copper fila duck, tinned copper threads, polyester filament yarns covered with copper and the like, to obtain adequate shielding attenuation values. Because of the susceptibility of the metal filaments, in particular to breakage, or the metal fibers being worked out during practical use, such carrier materials are only of limited suitability.

A further disadvantage of the known carrier materials with metal layers was that there was insufficient corrosion resistance and / or abrasion resistance. Oxidations often occurred, which in turn impaired the protective effect of the metals. In the military area, too, there are dangers for people who, for example, have to be in the immediate vicinity of ra systems and / or move. In addition, these people should also be able to camouflage themselves from an enemy.

The present invention is therefore based on the object of creating an effective protective device of the type mentioned at the outset, which not only provides high shielding but also has good practical properties which are necessary for work, such as e.g. good abrasion resistance, washability and breathability or air permeability and therefore no body heat build-up (also no heat absorption by the fabric). In addition, the protective device for military purposes should ensure camouflage against thermal imaging devices for the person carrying it.

According to the invention, this object is achieved by the features mentioned in the characterizing part of claim 1.

While the polyamide fibers or yarns covered with a silver layer provide a very good shielding effect against electromagnetic high-frequency fields and, surprisingly, camouflage in the thermal image is achieved, the covering of these fibers or yarns with a polymer layer ensures appropriate stability or the polymer protects the yarn or the fibers and the silver against environmental influences. In addition, washability and abrasion resistance are achieved in this way. It is only necessary to ensure that no closed layer or no closed carrier material is achieved by the covering with a polymer layer, so that breathability remains. It just wraps the fibers or yarns carried out. Gaps or pores remain between the yarns or fibers.

The polymer layer also provides good temperature resistance and high cold flexibility. In addition, resistance to weak acids, alkalis and electrolyte solutions, e.g. through sweating. In addition, the carrier material or the base material has good light, weather, aging and hydrolysis resistance.

Despite the polymer coating, a high reflection of the metal, namely the silver layer, is retained. In addition, the conductivity and the emission coefficient (e = 0.2) of the carrier material are not prevented.

It is also essential that the polymer coating prevents silver sulfide formation.

Practical tests have shown that the polymer layer adheres well to the silver layer with very good abrasion resistance. The carrier material formed in this way is not only washable, but also dry-cleanable.

The production of the base material or carrier material according to the invention can advantageously be carried out by applying a crosslinking polymer, for example a crosslinking polymer, to polyamide fibers or polyamide yarns that have already been completely metallized with a silver layer. Polydimethylsiloxane polyacrylate is applied.

Instead, coating can also be carried out by padding. Foularding is a kind of immersion bath with rollers over which the yarns or the fabric, braid, fleece or the like are guided.

The fibers or yarns provided with the polymer layer are then briefly heated to a temperature between 160 and 180 ^° C. after the drying process, as a result of which crosslinking takes place. During the crosslinking, a chemical conversion takes place, the radicals of the polymer jumping open and crosslinking into larger groups. This results in a structurally modified, stable material.

Advantageous further developments and refinements of the invention result from the subclaims and from the exemplary embodiment described below with reference to a drawing.

It shows:

Fig. 1 schematic representation of a protective suit;

2 greatly enlarged a section of a carrier material for a protective suit.

The base material for the protective suit is polyamide fibers or polyamide yarns 1, which are also known under the trademark nylon, as 6.6 ripstop fabrics or as so-called parachute silk. Such a fabric is completely covered with 35% by weight of a pure silver layer 2 and thus metallized, ie each individual fiber of the fabric has a complete silver coating with very good adhesion. The fabric created in this way can have a weight class of approximately 50 g / m ² .

On this fabric, for example as a woven fabric, as a fleece or 2 to 5 g / m ² (dry), a crosslinking polydimethylsiloxane polyacrylate is applied via an application process, the silver layer 2 being sealed by the resulting polymer layer 3. More polymer should not be applied, since polymers tend to absorb more heat.

The application can also be carried out by so-called fouling.

After a drying process, the fabric is briefly heated to temperatures of 160 to 180 ° C. in order to achieve crosslinking.

From the greatly enlarged illustration in FIG. 2 it can be seen that the pore size of the fabric is selected so that even after being coated with the polymer layer 3 there is still sufficient space or pores between the individual fibers or yarns so that breathability is achieved preserved.

The carrier material produced in this way is now made up into a protective suit in such a way that proper shielding and, if desired, camouflage of the human being is achieved by making up a whole body.

A one-piece protective suit 4 in overalls form is preferably provided, which is provided with a nickel-plated zipper 5 at the appropriate points. If necessary, nickel-plated hook-and-loop fasteners are of course also possible.

To maintain the shielding, the protective suit 4 must not ne wide sleeves and pants ends so that the radiation can not penetrate. For this reason, the ends of the sleeves and trousers will be kept tight with zippers or elastic bands.

It should also be noted that in the separation areas of the suit, there must be an overlap of base materials, generally of at least 15 cm. Otherwise, appropriate adhesive strips would have to be used.

For this reason, the gloves 6 and socks 7 will be made of the same material as the protective suit 4 and correspondingly long with gauntlets and an elastic band. For good durability, the socks will generally be designed with a double outsole. Shoes 8 must be electrically conductive, e.g. be provided with appropriately designed PVC soles so that they do not become electrostatically charged.

A protective helmet or hood 9 is to be provided over the protective suit 4 in the head area, which is made of the same material as the protective suit 4. The protective helmet 9 or the hood is to be closed by a face shield 10 and in the protective suit can be integrated inside with a large overlap.

A mesh fabric or lattice bars 11 coated with metal is used as face protection or visual field 10.

The protective suit 4 will generally be worn in the civilian sector as a base suit for protection against the electromagnetic fields in the MHz / GHz range, over which a normal work suit is then put on, so that the protective suit 4 against damage, thereby reducing the shielding effect would be compromised.

Of course, the protective suit 4 could also be formed in one piece as a complete work suit by a corresponding combination with a conventional work suit or an externally attached material.

When the protective suit 4 is used in the military field, a function in thermal imaging in the sense of camouflage being desired, the suit must be worn as an upper suit in order to create camouflage in relation to thermal imaging devices. In this case, in contrast to working in the civilian sector, it is not absolutely necessary to protect the protective suit from damage. This means that in this case, in addition to protection against electromagnetic fields, e.g. in the immediate area of radar systems, there is also camouflage.

Of course, the protective suit can also be used as a camouflage suit for people, even if there are no health problems due to electromagnetic fields. As mentioned, it has been found that a protective suit in the specified composition is outstandingly suitable for camouflaging people in the thermal imaging area.

Experiments in practice have shown that very good shielding effects were achieved with the protective suit according to the invention. It was found, for example, that the average protective effect is more than 40 dB for electrical field protection, and below 500 MHz even 60 dB. Dipole antennas set to the main frequencies were used for the measurements of the electric field. The measurement was made in horizontal and vertical Position or polarization at heights of 1.25 and 1.80 m.

Loop antennas were used for the measurement of the magnetic field, measurements also being carried out in horizontal and vertical positions or polarization. As a result, it was found that the protective suit 4 offers protection against:

10 MHz = 15 dB 100 MHz = 25 dB 200 - 1000 MHz = 40 - 60 dB for magnetic fields.

The shielding attenuation for electromagnetic radiation is effective in a frequency range from 100 MHz to 100 GHz, the minimum shielding attenuation being 20 dB.

Of course, the above values are only to be seen as examples. The values obtained can be different according to the local conditions, the design of the protective suit 4, the frequencies and the like.

For camouflage against thermal imaging devices in the thermal imaging range of, for example, 10 ¹² to 10 ¹⁵ Hz, the suit must be worn as an upper suit. For the required camouflage in the optical and near infrared, only 50% of the area with color green and black is applied as camouflage on the outside of the protective suit 4. The remaining 50% of the area remains the urban, generally brown, inherent color of the fabric.

Experiments have shown that a protective suit 4 in the specified composition does not radiate any heat visible in thermal imaging devices and also does not radiate heat from outside. takes what he is excellently suited for military purposes.

Claims

Expectations

1. Protection device for people to shield against electromagnetic high-frequency fields and / or for camouflage against thermal imaging devices with a carrier material in the form of a suit surrounding people, which is provided with shielding fibers, yarns or additional shielding components, characterized in that a base material for the Carrier material or the carrier material itself has polyamide fibers or yarns (1), which is covered over its entire area with a silver layer (2) and that a polymer layer (3) is applied on the outside over the silver layer (2), which seals the fibers or yarns metallized with the silver.

2. Protection device according to claim 1, so that the polyamide fibers (1) are coated with a layer of 30 to 40%, preferably 35% by weight, of pure silver.

3. Protection device according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t that is used as polyamide 6.6 ripstop fabric.

4. Protection device according to claim 1, 2 or 3, characterized in that the base material or carrier material has a weight of about 40 to 60 g / m ² , in particular 50 g / m ² .

5. Protection device according to claim 4, d a d u r c h g e k e n n z e i c h n e t that crosslinking polymer is used as the outer layer.

6. Protection device according to claim 5, d a d u r c h g e k e n n z e i c h n e t that polydimethylsiloxane polyacrylate is used as the polymer.

7. Protection device according to claim 6, d a d u r c h g e k e n n z e i c h n e t that zippers (5) required for the suit (4) are nickel-plated.

8. Protection device according to claim 1 to 6, d a d u r c h g e k e n n z e i c h n e t that Velcro fasteners provided for the suit (4) are nickel-plated.

9. Protection device according to one of claims 1 to 8, d a d u r c h g e k e n n z e i c h n e t that overlaps are provided in separation areas of the suit (4).

10. Protection device according to claim 9, d a d u r c h g e k e n n z e i c h n e t that the overlaps are at least 15 cm.

11. Protection device according to one of claims 1 to 10, characterized in that gloves (6) also have polyamide fibers or yarns (1) which are coated with a silver layer (2) over the entire surface, and that on the outside over the silver layer (2) a polymer layer (3) is applied, which fibers or metallized with the silver Sealed yarn.

12. Protection device according to one of claims 1 to 11, characterized in that socks (7) are provided, which also have polyamide fibers or yarns (1), which are coated with a silver layer (2) over the entire surface and that on the outside a polymer layer (3) is applied to the silver layer (2) and seals the fibers or yarns metallized with the silver.

13. Protection device according to one of claims 1 to 12, characterized in that a protective helmet or a hood (9) is provided, which also has polyamide fibers or yarns (1) which are coated with a silver layer (2) over the entire surface, and that on the outside A polymer layer (3) is applied over the silver layer (2) and seals the fibers or yarns metallized with the silver.

14. Protective device according to claim 13, characterized in that the protective helmet or the hood (9) is provided with a face field (10) made of rust-free metal mesh, and that the protective helmet or the hood (9) is closed and in the protective suit (4th ) is integrated with overlap.

15. Protection device according to one of claims 1 to 14, d a d u r c h g e k e n n z e i c h n e t that shoes (8) are provided which are electrically conductive.

16. Protection device according to one of claims 1 to 15, characterized in that camouflage is applied to the outside of the suit (4).

17. A method for producing a protective device according to one of claims 1 to 16, characterized in that polyamide fibers or yarns (1) polymer coated on the entire outside with a silver layer (2) are applied to both sides via an application process, the silver layer (2 ) is sealed.

18. The method according to claim 17, characterized in that approximately 2 to 5 g / m ^{2 of} a crosslinking polymer is applied per side.

19. The method according to claim 17, so that the coating of the polyamide fibers or yarns (1) provided with a silver layer (2) with polymer is carried out by padding.

20. The method according to any one of claims 17 to 19, so that after the coating with polymer a brief heating to a temperature between 160 and

180 ° C for crosslinking is carried out.