WO2008148138A1

WO2008148138A1 - Luminescent textiles

Info

Publication number: WO2008148138A1
Application number: PCT/ZA2008/000044
Authority: WO
Inventors: Dick Kongolo
Original assignee: Coetzee, Frederick, James
Priority date: 2007-05-28
Filing date: 2008-05-27
Publication date: 2008-12-04

Abstract

A luminescent textile has an electrically conductive filament, such as silver, woven into a nonconductive filament fabric, the fabric having a layer of phosphor and being coated with an insulating layer that is, in turn, coated with a conductive layer to form an electrode, the conductive filament constituting the other electrode. An electrical current energizes the phosphor layer to emit a predetermined luminosity.

Description

LUMINESCENT TEXTILES

TECHNICAL FIELD OF THE INVENTION

This invention relates to luminescent textiles and to a method of producing them.

BACKGROUND ART

It is known to provide laminates for luminescent textiles in which successive laminas comprise electrode, layer of phosphor, insulating layer and another electrode. Current is passed and the phosphor is activated. However, it is only possible in the present state of the art to use very small areas, for example the screen of a cell phone, because of the large current required. Another arrangement is to surround the laminas with a bus bar to provide the required current and larger areas are then possible but the power consumption is high.

The prior art arrangements are quite thick and not very flexible, which limits their applications. In addition, it has been difficult to obtain uniform luminescence.

Another limitation of prior art luminescent textiles is that they are generally opaque or only of limited transparency.

It is an object of the present invention to provide a flexible fabric of uniform luminescence in which only a small current is required - so that large areas can be illuminated; and printing can be securely held. The fabric of the invention may be used for a multitude of applications, such as protective clothing, roll-up fabrics e.g. for maps, TV screens, advertising such as on buildings, tent flaps, incontinence devices and many others. DISCLOSURE OF THE INVENTION

According to the invention a luminescent textile includes an electrically conductive filament woven into a nonconductive filament fabric, the fabric having a layer of phosphor and being coated with an insulating layer, that is in turn coated with a conductive layer to form an electrode, the conductive filament constituting the other electrode; and an electrical current to energize the phosphor layer to emit a predetermined luminosity.

The conductive filament may comprise the warp or weft of the fabric and the nonconductive filament the weft or warp respectively. However, the conductive filament may be woven in either direction or both directions of warp and weft in a woven textile of nonconductive filaments. The conductive filament may be woven in the form of a mesh in the nonconductive filaments.

The conductive filaments may be made from any suitable ductile metal or other substance. Silver has been found to be particularly useful as it may be drawn into very fine filament with excellent tensile strength.

In one form of the invention the silver filament may be wound around with an elastomer to take up any expansion or contraction of the silver.

The nonconductive filament fabric may also be chosen from a wide variety and it has been found that nylon of very narrow gauge (low denier) is preferred. The nylon or other thread is chosen for the important property of transparency and flexibility as well as having acceptable adhesion of ink.

In order to prevent contact between the silver filament and the other electrode (causing short circuiting), a method has been devised whereby the textile is compressed prior to the application of the other laminas (phosphor, insulating layer and electrode) by the application of high pressure - for example using a press (up to 60 tons pressure)- so that the silver filament, that may be in sinuous configuration due to being wound with the elastomer is squashed for containment within the thickness of the warp and weft so there is no penetration therethrough and through the insulation layer.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is described below with reference to the accompanying drawing and photographs.

Figure 1 is a representation of the textile that forms the basis of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Filaments of silver 10 are woven with the warp and weft of nylon filaments 12 in the form of parallel lines.

The sample in Figure 2 comprises silver filaments that are woven in the form of a mesh with the advantage that the current is reduced by a quarter and that an excellently uniform luminescence is obtained. The silver filaments are wound with a thread of a suitable elastomer. A base yarn 16 of nylon or the like supports the mesh.

The mesh structure is subjected to a high pressure treatment in order to compress the filaments into the elastomeric fibres so that there is no penetration of the silver into the electrode (described below).

This is illustrated in Figure 3 in which the silver filaments 10 are wound with an elastomeric fibre 18.

In Figure 4 a press 20 is applied to the textile containing the wound filaments so that the silver filaments are compressed to be contained in the thickness of the elastomeric fibres, as shown by reference 22. Figure 5 illustrates, in cross-section, the textile and the added laminas of phosphor 18, insulation material 20, and electrode coating 22.

The phosphor may be chosen from virtually any commercially available phosphors, the insulating layer may comprise a suitable polymeric material.

It will be appreciated that the second electrode may comprise another textile such as the one described above. The use of the second textile is particularly important if a completely transparent or translucent product is required, since most of the possible materials for use as the electrode coating are not translucent or only slightly so.

Figure 5 also illustrates the electrical connections 24. The source of electrical current may be derived from dry cells, wet cells, mains or other source.

Figure 6 is a microphotograph of a luminescent textile made according to the invention.

Figure 7 is a view similar to that of Figure 1 , the silver filaments 10 being woven into the weft and warp

The invention has a multitude of applications, including vehicle panels for internal illumination, advertising, safety equipment and clothing, furniture, refrigerator doors, interior of refrigerators, interior of cupboards, inside of handbags, TV roll-up screens and many others.

Claims

CLAIMS:

1. A luminescent textile characterized in that an electrically conductive filament is woven into a nonconductive filament fabric, the fabric having a layer of phosphor and being coated with an insulating layer, that is in turn coated with a conductive layer to form an electrode, the conductive filament constituting the other electrode; and an electrical current to energize the phosphor layer to emit a predetermined luminosity.

2. The luminescent textile according to Claim 1 characterised in that conductive filament comprises the warp or weft of the fabric and the nonconductive filament the weft or warp respectively.

3. The luminescent textile according to claim 1 characterised in that the conductive filament is woven in either direction or both directions of warp and weft in a woven textile of nonconductive filaments.

4. The luminescent textile according to claim 3 characterised in that the conductive filament is woven in the form of a mesh in the nonconductive filaments.

5. The luminescent textile according to any of the above claims characterized in that the conductive filaments are made from a ductile metal or other substance.

6. The luminescent textile according to claim 5 characterised in that the metal is silver.

7. The luminescent textile according to claim 5 or 6 characterized in that the metal filament is wound around with an elastomer to take up any expansion or contraction of the metal.

8. The luminescent textile according to any of the above claims characterized in that the nonconductive filament fabric is nylon of very narrow gauge (low denier).

9. A method of manufacturing a luminescent textile according to any of the above claims characterised by the step of compressing the textile prior to the application of the other laminas (phosphor, insulating layer and electrode) by the application of high pressure) for the silver filament in sinuous and wound configuration with the filaments of the textile, is squashed for containment within the thickness of the warp and weft for there to be no penetration therethrough and through the insulation layer.