JPH02122700A - Building-shaped shielding wall covering - Google Patents

Abstract

PURPOSE: To provide good shielding easily and at a relatively low cost by laying a mixed layer of conductive fiber and nonconductive fiber with a particular composition ratio between them. CONSTITUTION: Vinyl is laminated to 20 microns and has a backing of 10g/m<2> unwoven material consisting of 100% graphite cover with nickel, and this is formed by an unwoven mat of 51g/m<2> containing 50% of nickel-covered graphite fiber and 50% of polyethylene terephthalate fiber. And as other useful non- conductive fibers, polyethylene fiber or glass fiber is available. Also, the backing material is used for covering the walls and the ceiling of a room or the wall, ceiling and floor, which is then covered with a plastic material, and then a 51g/m<2> unwoven material layer containing glass fiber and polyethylene terephthalate fiber covered with 50% nickel and 20 micron vinyl is laminated in such a manner that their joints can be arranged in a staggered pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to architectural shielding of enclosures through the use of conductive nonwoven composite wall coverings and ceiling mats.

[Prior Art and Problems to be Solved by the Invention] An enclosure housing a device such as an instrumentation, a computer, a sensitive electronic device, etc.
Shielding from electromagnetic interference (EMI) generated internally or externally (a device) prevents the shielding of structures shielded from being penetrated by means that rely on electromagnetic radiation for detection, and This is necessary to protect the structure from malfunctions caused by radiation.

The use of plastics instead of metals in electronic equipment has created a need for increased protection from electromagnetic interference. Plastics cannot absorb or reflect electromagnetic radiation like metals. The above protection usually requires the use of shields, filters and special circuit membranes.

Many electronic devices are sensitive to electromagnetic interference.

It can also generate uncontrolled electromagnetic fields. Without some form of electromagnetic interference (E-II) shielding, electromagnetic radiation can damage or interfere with electronic equipment. Such radiation can also be picked up by sophisticated electronic equipment. Depending on the electromagnetic interference (EM I )/ik emission source, this electronically stolen information may be used for espionage purposes or altered and transmitted back to the emitting device.

An example of this exists in the computer field, where modification and theft of computer data bases is prevalent.

Furthermore, government agencies and laboratories are plagued by microwave and other high frequency It electromagnetic fields. These people, and the sensitive electronic equipment they handle, require protection from electronic waves. One solution to this problem has been to place the instrumentation and/or computers within a room surrounded by metal walls. However, this solution was expensive, impractical, and cumbersome.

Now 1' architectural shielding method is to empty a room, install a metal cage, and inside the cage I'j f
& Is there a need to build one?

It is an object of the present invention to provide architectural shielding (electromagnetic interference [EMI] shielding) to walls and ceilings by incorporating conductive nonwoven mats into wall covering panels and ceiling panels. The architectural shielding described herein has a relatively low l1IIiF8, is easy to install in existing rooms, and yet provides good shielding ('electromagnetic interference [EM I ] shielding).

[Means for solving the problem] Electromagnetic interference (EMI) and radio frequency interference (RFl)
) shielding is made of nickel i, laminated on a vinyl mat.
It is achieved through the use of a non-woven pine wall covering of coated graphite (NCG)/polyethylene terephthalate fibers.

The wall covering is installed over the four walls and ceiling of a room with a 22 gauge stainless steel floor. The wall covering is backed with nickel-coated graphite to prevent leakage.
ing) placed on the feed. A self-contained wall covering is provided on the backing material with seams of the wall covering alternating with seams of the backing material.

Traditionally, effective RFI/EMI shielding has been achieved using conductive fibers or metallized fiber fabrics.
It was believed that such shielding could only be achieved by inherently conductive fibers, metallized fibers, or other conductive elements such as wires - comprising 100% tightly woven fabrics. . Surprisingly, however, it has been found that effective RFI/EM I and tjq shielding can be obtained even with nonwoven mats in which only some of the fibers are conductive fibers.

-9, the present invention uses graphite laminated to 20 micron vinyl and nickel coated 10
The nonwoven is backed by a lOg/rd nonwoven consisting of 006 and 5Lg/rd nonwoven containing 5096 nickel-coated graphite fibers and 50?6 polyethylene terephthalate fibers. Provides wall covering for electronic shielding consisting of mats.

Other nonconducting fibers useful for the present invention include polyethylene fibers or glass fibers.

In another aspect, the present invention provides a backing material to the walls and ceiling, or walls, ceiling, and floor of the room; coats the backing with standard plastic; Coated graphite fiber and polyethylene
51g/rr1″ containing terephthalate fiber
A method for electronically shielding a structure consists of laminating layers of non-woven material such as 20 microns and 20 micron vinyl with alternating seams.

In general, electromagnetic waves are oscillations from many different sources'<I
s '6: Generated by i. Microcomputers, electric motors, engine ignition systems, electrical equipment, high frequency eavesdropping equipment, and lightning are some examples of electromagnetic sources.

The frequency of the electromagnetic waves is measured in cycles of 7 seconds or Hertz (llz).

The electromagnetic spectrum consists of electromagnetic waves ranging from OHz to 10”Hz. In order of frequency, the spectrum includes radio, infrared, visible, ultraviolet, X-ray, gamma-ray, and cosmic ray waves. Electromagnetic and radio frequency interference (EMI and RFl) is caused by the uncontrolled radiation of electromagnetic fields from man-made electronic devices.
00+1z) -10G112 (101011Z) frequency range.

+A materials that absorb and reflect electromagnetic waves are EMI and RF
It can be shielded against l. The electromagnetic wave component of the electric field can be reduced by using metals or other conductive materials such as carbon.
, J or absorbed (magnetic field electromagnetic wave components can only be reflected or absorbed by using ferromagnetic materials such as iron, nickel or cobalt).

+ The shielding efficiency (SE) of the material is determined by the electromagnetic field or the material.
Apj is determined by comparing the strength of the electromagnetic field before and after interaction.

Let the strength of the magnetic field be 7 before Rashi A, reaches the material,
If it is the strength of the electromagnetic field after being absorbed or reflected by A7 or its material, then the following formula holds: A-=A 2 A3, where A is the reflection by the shielding material. and loss of electromagnetic field strength due to absorption. IIp
The determined electromagnetic field is expressed as the ratio of intensity levels, namely: SE vs - 201ogA3/A2, and this formula describes the shielding efficiency of the material as the level of attenuation of the electromagnetic field in denbels (dIl). giving.

Since the shielding efficiency is a logarithmic function, 10 dB in attenuation
The increase in , as shown in Table 1, is a tenfold reduction in the electromagnetic field. Requirements for typical architectural shielding stages range from 40 to 100 dB.

Table 1 The relationship between shielding efficiency and reduction in EMI is as follows: Shielding Efficiency (dB) E M I Reduction (%) 30
99.9 4099.99 50 99.999 130 99.9999 Non-woven mats practiced in the present invention employ conductive fins of the heel type, which are selected for the particular desired end result. be done. These include PAN heath carbon fiber) <1 aluminized glass fiber;
Nickel coated graphite plate I), copper plated plated stainless steel plate 1'
There are some iron graphs and carphone fibers.

The carbon fiber of PAN Heath is Polyacrylic J Kuroni I
- Made from Lil (PAN) precursor fiber, contains 95796 carposis and is different from graphite phi.1. Genuine graphite phyno or carbon 999
Contains over 6.

The aluminized glass fiber is aluminum coated alkali-free glass fiber 1<.

Nickel coated graphite (N CG ) is a PAN-based carphone fiber electroplated with nickel.

Pre-jQ N CG fiber is the preferred fiber for the present invention, it has excellent electrical resistivity and high 11.5
This is because it has corrosion resistance. As a result, the NCG fiber is able to maintain a high level of electrical conductivity at the interface between two adjacent fibers/X.

Stainless steel fibers and/or nickel-fall glass or carbon fiber substrates are often used in applications where some degree of magnetic shielding is required.

The present invention will be more clearly understood by referring to the following experiments. The rooms are 10KIlz, 50KIIZ, 1oO between 1OKIlz and 10CI+7°
KIIz, 500KIIz.

I Mllz SlooMIIZ, 500MIIZ,
It was tested for electromagnetic shielding efficiency at nine frequency levels: IGIIZ and l0CIIZ. Two room configurations were tested. The first (1'4) is the one in which the walls, ceiling and floor are all shielded.Then, the ceiling is removed and only the walls and floor are shielded (second configuration). was tested.

The shielding efficiency test is a method for determining attenuation for electromagnetic shielding enclosures for electronic testing purposes + MIL standard 285.
(MIL-8TD-285).

In FIG. 1 the test case deafness is shown schematically, and in FIG. 2 the test equipment is depicted.

Electromagnetic field levels were measured at each frequency.

The receiving antenna was placed in the room, 1 meter away from the transmitting antenna outside the room. The door to the room was bolted and the electromagnetic shielding efficiency of the room was measured. After that, the test operation described above,
Repeated for a second room configuration where only the floor and walls were shielded.

FIG. 3 shows the shielding efficiency D m of an architectural nonwoven composite wall covering.

In the frequency range from 10Kllz to 50Kllz, the shielding efficiency of the architectural wall force/wall system exceeded the measurement capabilities of the test equipment. This has been tested (i+
This occurs when the color imaging efficiency of 2[ exceeds the dynamometer of the test system. The overall shielding efficiency of the two Wahlka\ring systems 47.7 described above is excellent. The first configuration in which walls, floors, and ceilings are shielded has a total jJ
In one wave number range, it is larger than l [ldB. 2nd R, 7
The configuration illustrates the level of shielding that can be expected with the wall covering system when used in a cubicle or other open office structure.

In the screen configuration, shielding tests of front wall covering panels show a small dip in the level of shielding efficiency, which is due to the interaction of the electromagnetic fields based on the geometry of the test equipment.

The electrically conductive fiber fabric of the present invention provides effective and economical architectural protection against EMI.

Irregularly distributed conductive fibers provide greater electrical conductivity than directionally distributed conductive fibers due to more fiber-to-fiber contact.

Wet-laid nonwoven technology provides a random distribution of fibers and is the preferred form for creating the desired conductive/non-conductive mixture.

Furthermore, easy handling and installation of the shielding material 4' is desirable for one or two industries. The present invention accomplishes the above needs by providing a shielding medium that can be quickly and easily installed without the need for special tools or advanced technology. As a result, the installation work can be done at low cost and with less downtime.

[Brief explanation of drawings]

Figure 1 is a top view showing the structure used in the architectural color efficiency test, Figure 2 is a chart showing the room shielding efficiency (test equipment used for measurement), and Figure 'B' is a new 1 is a graph of shielding efficiency for wall covering systems; AFN frequency (MHz) in X8's room 2 l-,, (covered t nigella phyto: 00% ・tsu t-kahari/gu 26 g/i Q 2, ke L-5 and 1) Two graphs are set up in a room of 8 x 8' W 8. Fig. 3

Claims (1)

[Claims] [1] 50% conductive fiber and 50% non-conductive fiber
Non-woven architectural screening wall covering laminate characterized in that it comprises a mixed layer of %. [2] The laminate according to claim 1, further comprising a structural vinyl resin matrix layer. [3] The conductive fiber may be a copper-plated alkali-free glass fiber, a nickel-coated graphite fiber, an aluminum-coated alkali-free glass fiber, a polyacrylonitrile-based carbon fiber, a stainless steel fiber, or a nickel-iron coated fiber. 2. The laminate according to claim 1, wherein the laminate is a nickel-iron coated carbon fiber or a nickel-iron coated carbon fiber. [4] The laminate according to claim 1, wherein the non-conductive fiber is a polyethylene terephthalate fiber, a polypropylene fiber, or a glass fiber. [5] Nickel-coated graphite fiber, aluminum-coated alkali-free glass fiber, copper-plated alkali-free glass fiber, polyacrylonitrile-based carbon fiber, stainless steel fiber, nickel-iron coated glass fiber or nickel-coated glass fiber. The laminate of claim 1 further comprising a backing layer of 100% conductive fibers selected from the group consisting of iron-coated carbon fibers. [6] A non-woven architectural shielding wall covering characterized in that it comprises (a) a mixed layer of 50% conductive fibers and 50% non-conductive fibers, and (b) a structural vinyl resin matrix layer. A method of shielding the contents of a room, consisting of covering the walls and floor of the room. [7] The conductive fiber is a nickel-coated graphite fiber, an aluminum-coated alkali-free glass fiber, a copper-plated alkali-free glass fiber, a polyacrylonitrile-based carbon fiber,
7. A method according to claim 6, characterized in that it is a stainless steel fiber, a nickel-iron coated glass fiber or a nickel-iron coated carbon fiber. [8] The method according to claim 6, wherein the non-conductive fiber is a polyethylene terephthalate fiber, a polyethylene fiber, or a glass fiber. [9] Nickel-coated graphite fiber, aluminum-coated alkali-free glass fiber, copper-plated alkali-free glass fiber, polyacrylonitrile-based carbon fiber, stainless steel fiber, nickel-iron coated glass fiber or nickel-coated glass fiber 7. The method of claim 6, further comprising a backing layer of 100% conductive fibers selected from the group consisting of iron-coated carbon fibers. [10] A non-woven architectural shielding wall covering comprising: (a) a mixed layer of 50% conductive fibers and 50% non-conductive fibers; and (b) a structural vinyl resin matrix layer. Consists of covering the walls, floor and ceiling of the room,
A method of shielding the contents of the room. [11] The conductive fiber may be a nickel-coated graphite fiber, an aluminum-coated alkali-free glass fiber, a copper-plated alkali-free glass fiber, a polyacrylonitrile-based carbon fiber, a stainless steel fiber, or a nickel-iron coated fiber. 11. A method according to claim 10, characterized in that the fiber is a nickel-iron coated carbon fiber or a nickel-iron coated carbon fiber. [12] The method according to claim 10, wherein the non-conductive fiber is a polyethylene terephthalate fiber, a polyethylene fiber, or a glass fiber. [13] Nickel-coated graphite fiber, aluminum-coated alkali-free glass fiber, copper-plated alkali-free glass fiber, polyacrylonitrile-based carbon fiber, stainless steel fiber, nickel-iron coated glass fiber or nickel-coated glass fiber. 11. The method of claim 10, further comprising a backing layer of 100% conductive fibers selected from the group consisting of iron-coated carbon fibers.