JPH037897A - Camouflaging sheet - Google Patents

Abstract

PURPOSE:To obtain a camouflaging sheet which possesses a high anti-far infrared ray barrier effect and a camouflaging effect and is light weight, flexible and a sufficiently permeable by combining into one piece a sheet having a camouflaging effect against at least one kind of light or wave with a sheet having an irregular twisted surface structure by knitting plastic tapes. CONSTITUTION:The present camouflaging sheet is a composite fabric sheet combining a sheet A which has a camouflaging effect against at least one kind of light or wave selected from a group composed of visible light, near infrared ray, ultraviolet ray and radar wave and a sheet B which is composed of sheet of knitted plastic tapes and presents an irregular surface structure because of the twisted tapes. The plastic tapes which form the sheet B desirably has a far infrared ray absorption coefficient of greater than 50% and a spacing ratio of less than 20%, and the spacing is desirably made less than 20mm. For a sheet A, various kinds of camouflaging sheets are applicable such as a two dimensional sheet or a three dimensional sheet having a three dimensional characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite sheet that has a camouflaging effect against far infrared rays as well as a camouflaging effect against other light and waves.

<Conventional technology> Along with recent advances in various defense technologies, there have been remarkable advances in detection and reconnaissance technology.
In addition to methods that use ultraviolet rays, radar waves, etc.32, methods that use far infrared rays are attracting attention.

In particular, unlike conventional methods, this method captures and visualizes far-infrared rays (commonly referred to as heat rays) emitted from the object being detected and reconnaissance, so it can be detected both during the day and at night.・It is possible to perform reconnaissance, and because the far infrared rays 1 have a long wavelength, it is not easily affected by fog, smoke, etc., and is an extremely preferable method for reconnaissance against military objects such as tanks and airplanes. Generally said.

Detection and reconnaissance technology and camouflage technology to conceal it are related, and when new detection and reconnaissance methods appear, there is a strong need for methods to disguise them.

Currently, various methods have been proposed to effectively disguise military objects using far-infrared detection and reconnaissance.
Alternatively, a camouflage sheet using aluminum foil or the like with low far-infrared radiation is known, but the heat insulating cloth has problems in operability in covering and camouflaging a tank etc. with the sheet in a short time.
Aluminum foil is lightweight and has no problem with operability, but it shines and has an unfavorable effect on other reconnaissance means, such as visual (visible light) means.

In addition, various types of camouflage sheets or net-like materials have been developed that have a camouflage effect against visible light, ultraviolet rays, near-infrared rays, radar waves, and far-infrared rays. There is no known device that can simultaneously camouflage against both various light rays or radar waves and far infrared rays (heat rays). Therefore, there is no camouflage material made of a single composite sheet that has a barrier effect against heat rays emitted from vehicles, etc., and at the same time satisfies camouflage properties against other detection waves.

Furthermore, the conventional far-infrared camouflage sheet described above does not have ventilation, so if it is installed outdoors and is exposed to the wind, its condition will not be stable, and in some cases it may be damaged. The work can also be difficult.

<Problems to be Solved by the Invention> The present invention provides a camouflage sheet that has both an excellent far-infrared barrier effect and other camouflage effects, is lightweight, flexible, has appropriate ventilation, and is easy to handle. This is what we intend to provide.

Means for Solving the Problems> That is, the present invention comprises a sheet A having a camouflaging effect against at least one type of light or wave selected from the group consisting of visible light, near infrared rays, ultraviolet rays and radar waves, and a synthetic resin tape. Sheet B is made of a woven sheet and has an irregular surface structure due to the twisted tape.
This is a composite fiber sheet with an integrated structure.

Preferably, the far infrared absorption rate of the synthetic resin tape constituting sheet B is 50% or more, and the porosity of sheet B is 50% or more.
% or less, especially 20% or less, and the gap width is 20 g++s or less.

The sheet A in the present invention includes a two-dimensional sheet,
Various conventionally used camouflage sheets that are three-dimensionally processed to have three-dimensional properties can be used. For example, as a two-dimensional sheet, visible, ultraviolet and/or near-visible, ultraviolet and/or It is a sheet with paint, colorant, and partially perforated holes for ventilation so that the spectral reflectance in the infrared region approximates that of plants, soil, and/or snow in the natural world, and it can also be used as a three-dimensional sheet. There are two-dimensional sheets pasted onto a net-like fabric, or a simple colored resin sheet with slits made into a ribbon shape, which are then integrated.

In addition, fabrics designed to diffusely reflect or absorb radar waves and are camouflaged can be made into plain colored or camouflage patterned two-dimensional sheets, or ribbons of these, using the same method to create nets. An integrated three-dimensional sheet or the like can also be used.

As a means for obtaining camouflage against radar waves, known means can be applied, such as conductive metals,
Disguise materials include fabrics or sheets in which metsuki fibers are woven or knitted or a metal layer is integrated, coated with a colored resin layer if necessary, and attached three-dimensionally to a net-like fabric to diffusely reflect radar waves. It will be done.

Sheet B of the present invention is suitably woven from synthetic resin tapes, such as tapes made of film or ribbon tapes made of knitted fabric, and the tapes are twisted so that each tape surface is oriented in a random direction and there is no undesirable effect on the sheet. It has a regular surface or back structure and appropriate ventilation, and the tape material can be made of, for example, polyolefin, polyvinyl chloride, polyester, polyamide, polyvinyl alcohol, etc., but it is especially suitable for far-infrared absorbing materials. Preferred are resins such as polyvinyl alcohol and polyvinyl chloride.

A sheet having such a structure in which each tape surface is oriented in a random direction can be made, for example, by using a raschel knitted fabric in which tapes are inserted in the weft direction. In this case, since the tape is inserted into the chain stitches of the knitted fabric, it is appropriately twisted, and the tape surface is oriented in random directions between the chain stitches.

FIG. 1 is a plan view of the sheet B of the present invention showing its state, and FIG. 2 is a cross-sectional view taken along line A-A thereof, where l indicates a synthetic resin tape. As shown in FIG. 2, the sheet B of the present invention shown here has a tape surface facing in a random direction, and as a result,
Sheet B has an irregular surface structure and has sufficient ventilation. In this case, the warp yarns may be tapes, or ordinary threads or monofilaments.

In addition to the above-mentioned methods, methods for obtaining a structure in which each tape surface faces in a random direction include creating a primitive woven or knitted fabric using loosely twisted tape as a warp and/or tinsel;
There is a method of arranging loosely twisted tapes and adhering them to parallel lines of threads, tapes, etc., or to the surface of coarse knitted or woven fabric.

Sheet B of the present invention has the above-mentioned structure, and preferably has a straight far infrared transmittance of 20% or less, and when the transmittance exceeds 20%, a sufficient far infrared barrier effect cannot be obtained. Hateful. According to the structure of the present invention, a part of the far infrared rays emitted from the heat source is randomly reflected on the tape surface constituting the sheet B of the present invention, and a part of the far infrared rays is refracted and transmitted depending on the respective incident angles. Furthermore, some of the far infrared rays are absorbed by the tape itself, so overall,
It is thought that the far infrared rays emitted from the heat source are dispersed or diffused in random directions by the eight layers of the sheet, thereby significantly blocking the straight transmission of the far infrared rays.

In addition, in the present invention, if the porosity between each tape is too large, the straight transmittance of far infrared rays may increase depending on the size of each gap, so the porosity is reduced to 50%.
It is particularly preferable that the content be 20% or less. Furthermore, in the present invention, if the width of the gap is too large, the porosity will be small (far infrared rays will partially pass through in a straight line), so preferably the width of the gap is 20 ffim or less.

Further, the tape width is preferably 2 to 1 OIIlra.

Further, methods for laminating Sheet A and Sheet B include laminating a portion or the entire surface using heat or adhesive, or using clips, strings, or Sheet A and Sheet B.
Any method can be applied, such as attaching male and female magic fasteners by sewing and laminating them. Also, with these methods, it is possible to stack sheet B on both the front and back sides of sheet A, and if the front and back sides of sheet A are made in different colors or the area ratio of each color is different, sheet B can be stacked depending on the season or location. That sheet A
A structure in which the mounting surface can be freely selected is also possible by selecting the lamination method.

Incidentally, the far-infrared straight transmittance, far-infrared absorption rate, porosity, and gap width as used in the present invention are measured (defined) as follows.

・For far-infrared straight transmittance sheet B, use a known infrared spectrophotometer to draw the transmittance at a wavelength of 8 to 13 μm on a recording paper, and calculate the integrated area value A of the transmitted portion to the area value at 100% transmission. It is calculated by the following formula divided by B.

Straight transmittance (%) = X100 In the case of a machine with partially different transmittances, measurements are taken at multiple locations (usually n: 10 or more), and the measurement is defined by the average value.

・Far-infrared absorption rate Based on the principle that far-infrared absorption rate and emissivity (thermal emissivity) are equal, sheet B is constructed on a smooth aluminum hot plate at approximately 50°C as shown in Figure 4. After adhering the synthetic resin film and accurately measuring the temperature of the film itself with a contact thermometer (thermocouple type, etc.),
A far-infrared camera that can measure the temperature of an object by a non-contact method with a sensing range of 8 to 13 μm at a distance of 0.00 cm (e.g.
Industrial thermography manufactured by JEOL KK: JTG-
3200), and operate the thermal emissivity change dial attached to the far-infrared camera so that the temperature becomes equal to the temperature measured by the contact method. Find the ratio (0 to 1). The value obtained by multiplying the obtained emissivity by 100 is defined as the far-infrared absorption rate.

- Porosity is expressed as a percentage of the area of the gap in a certain area taken in a projection photograph of sheet B.

・Gap width: Indicates the width of the gap (mm) taken in a projection photograph of the same work. However, in the case of a circle or square, it depends on its diameter or side length. In addition, if the tape gap width is not uniform, multiple measurements are taken and the average value is shown.

Effect> According to the camouflage sheet of the present invention, the sheet A set on the outer surface camouflages a vehicle etc. against detection by visible light, ultraviolet rays, near infrared rays and/or radar waves, and The far infrared rays emitted from the heat source are randomly reflected on the tape surface constituting sheet B, refracted and transmitted according to each incident angle, and then absorbed by the tape itself, so that it is randomly dispersed, diffused, or absorbed by the eight layers of the sheet. Straight transmission of far-infrared rays is blocked, making it difficult for tanks and other vehicles to be detected by various types of external detection.

Further, since the camouflage sheet of the present invention is lightweight, flexible, and has appropriate ventilation, it is extremely easy to unfold and store the sheet.

Example 1 Thickness of polyvinyl alcohol (hereinafter referred to as PVA): 50
The μI film was slit into 5mm width pieces, and this tape and polyester multifilament 750dr were used in a warp knitting raschel machine to form a chain stitch structure in the warp direction using polyester yarn, and sheet B was made of various raschel knitted fabrics with the tape horizontally slit. Created.

On the other hand, a net-like material with a mesh structure of 80 x 80 mm is coated with soft PVC colored in light green, dark green, and brown on a metal-plated fiber-embedded fabric. Visible light, near-infrared rays, and radar are applied in three colors. A sheet A having a three-dimensional structure was prepared by adhering a ribbon-like material having a camouflaging effect.

These sheets A and B were laminated using 20 clips per 11,111 areas to form a camouflage sheet for IOX to♂.

Use a black, idling, water-cooled passenger car as the camouflage machine, use a ball so that the sheet A side of the laminated sort is on the outside, place the passenger car 1 (the seat is at least loc + n away from the passenger car), and move it to the forest. Based on this background, various types of deception were evaluated.

Evaluations are made from a distance of about 100 meters using known photographs for visible light and near infrared light, using a fishing boat radar for radar, and 8 to 13 μm for far infrared light.
This was carried out using a commercially available thermovision with a sensing range of

As a result, the far-infrared camouflage properties are shown in Table 1.

The camouflage performance against visible light, near-infrared rays, and radar showed exactly the same effect as the section H of sheet A, and the camouflage sheet of the present invention showed excellent far-infrared camouflage performance both during the day and at night.

*1: Indicates the evaluation temperature between daytime and nighttime. The temperature was 17°C during the day and 7°C at night.

Effects> Since the camouflage sheet of the present invention is characterized by a structure in which sheet A and sheet B are laminated, sheet B does not reduce the various camouflage effects of sheet A in any way, and is resistant to far infrared rays. It has an excellent shielding effect, and is also flexible and has appropriate ventilation, so even though it is a composite sheet, it has the same camouflaging effect as conventional visible light, ultraviolet rays, near infrared rays, and/or radar waves. It has excellent camouflage properties against far infrared rays, is not disturbed by wind, etc., and is easy to store, making it extremely useful as a camouflage sheet.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the sheet B constituting the present invention,'! J, Figure 2 is a schematic cross-sectional view of the A-A section,
In the figure, numeral 1 indicates a plastic tape. FIG. 3 shows a schematic cross-sectional view of a camouflage sheet in which sheet A and sheet B of the present invention are laminated. In the figure, 1 indicates sheet A12 and sheet B, and 3 indicates a laminated portion. FIG. 4 shows an example of a method for measuring far-infrared absorption rate, in which 1 shows an aluminum hot plate, 2 shows a sample for measuring absorption rate, 3 shows a far-infrared camera, and 4 shows the distance between the camera and the sample.

Claims (1)

[Claims] A sheet A having a camouflaging effect against at least one type of light or wave selected from the group consisting of visible light, near infrared rays, ultraviolet rays and radar waves, and a sheet made of a woven synthetic resin tape, and the tape is twisted. A composite camouflage sheet in which sheet B having an irregular surface structure is integrated.