GB2448764A

GB2448764A - Markable textile and method of manufacture thereof

Info

Publication number: GB2448764A
Application number: GB0708208A
Authority: GB
Inventors: Zahir Ahmed
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-27
Filing date: 2007-04-27
Publication date: 2008-10-29
Also published as: GB0708208D0

Abstract

A method of marking a textile comprises: providing a textile comprising a markable yarn, configured to emit visible light when exposed to ultraviolet radiation. The amount of visible radiation emitted by a portion of the yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion to a bleaching medium. The exposed portion is substantially indistinguishable using the naked eye from an unexposed portion when exposed to visible radiation and not to ultraviolet radiation. This is preferably achieved by including a fluorescent dye such as umbelliferon of 7-hydroxycoumarin within or upon the yarn. The dye may be included in the melt used to form the yarn. The bleaching is preferably achieved by exposing the yarn to a bleaching medium such as laser or ultraviolet light above a critical intensity, and preferably by scanning a laser beam over a portion of a textile comprising the yarn. Alternatively the bleaching medium may be X-ray or chemical. A mask, preferably LCD, may be used to define the portion of the textile exposed to the bleaching medium. The textile, preferably loom woven, incorporating the yarn may thus be marked to produce labels with alpha numeric characters, an image or a barcode.

Description

MARKABLE TEXTILE AND METHOD OF MANUFACTURE THEREOF

Field of the Invention

The present invention relates to markable textiles and a method of manufacturing a markable textile. In particular, but not exclusively, the invention relates to a method of marking a markable textile with an invisible security code.

Background

A number of different technologies are currently used for marking textiles with security labels and/or codes. For example, a marking may be woven into the textile material during manufacture of the material, such as by means of one or more weft threads of contrasting colour with another weft thread. Alternatively, the marking may be printed 15 onto the textile using an ink after the textile manufacturing process is complete.

The process of marking by weaving a welt thread of contrasting colour into the cloth requires special equipment typically including a computer control system. Furthermore, since the textile is marked during the process of manufacture, the code marked on the 20 textile must be known at the time of manufacture, and cannot be subsequently changed easily.

Marking of a textile by printing using an ink requires printing equipment in addition to textile manufacturing equipment. The ink used must be of high grade in order to resist deterioration during washing or exposure to light, for example fading of the textile. The process of printing is also relatively slow. Labels produced by printing typically take longer to make than labels produced by weaving alone.

In a first aspect of the present invention there is provided a method of marking a textile comprising the steps of providing a textile having a portion comprising a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, whereby the rnarkable yarn is configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the yarn to a bleaching medium, and whereby, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium; and exposing a portion of the textile to said bleaching medium.

Embodiments of the invention have the advantage that a textile may be conveniently marked after manufacture without a requirement for printing equipment such as ink-jet printing equipment. Furthermore, since no ink or other substance is required to be applied to the textile by the marking apparatus, the problem of fading or removal of the applied ink or other substance, for example during washing of the textile, does not arise.

Textiles such as labels, garments or other articles produced according to embodiments of the invention have the advantage that markings formed on the article according to embodiments of the invention are substantially invisible when viewed under normal lighting conditions. However, when viewed under UV light, the markings become visible.

****, 15 For example, in some embodiments the markings become visible when the textile is *.S.

irradiated with light from a UV lamp, such as a hand-held UV lamp. * .* *. * *** *

* Articles according to embodiments of the invention have the further advantage that they are difficult to copy. Thus, they are ideally suited to use as anti-counterfeit devices.

Textiles incorporating a markable yarn and marked using a bleaching medium can be readily distinguished from textiles not incorporating markable yarn. For example, they may be distinguished by inspection to determine the presence or absence of markings formed according to the method of the present invention. Thus, a marking applied by an approved marking entity would be expected to be visible on a non-counterfeit (ie a genuine) article when the article is exposed to UV radiation. A counterfeit article is an article not originating from an approved source, and therefore an article not comprising a markable yarn.

Markings according to embodiments of the invention may be referred to as invisible markings'. They are invisible markings in the sense that they are not visible to the naked eye when viewed under non-ultraviolet, visible radiation. They become visible to the naked eye only when viewed under ultraviolet radiation.

By attenuated' is meant a partial or complete absence of visible radiation emitted by the markable yarn as a consequence of exposure of the yarn to the bleaching medium. It will be appreciated that in the case of exposure of the markable yarn to a small amount of bleaching medium, a partial reduction in the amount of visible radiation emitted by the markable yarn as a consequence of exposure to the bleaching medium may occur rather than a complete elimination of the amount of visible radiation emitted. In contrast, in the case of exposure to a large amount of bleaching medium, for example to an intense beam of bleaching medium for a short or long period, a complete loss of an ability of the markable yarn to emit visible light in the presence of UV radiation may occur.

It will be appreciated that some textiles not having a markable yarn according to embodiments of the invention may emit visible light in the presence of ultraviolet radiation as a consequence of washing in a cleaning medium containing a brightening agent. Emission of visible light as a consequence of such washing is ignored for the purposes of the present invention. Such washing of textiles according to embodiments of the present invention may result in a reduction in a level of overall contrast between irradiated and non-irradiated areas when the textile is viewed under UV radiation.

:..::: 15 However, according to embodiments of the invention contrast is still visible to the naked **1* eye in textiles marked according to embodiments of the invention and subsequently L: . washed using a variety of cleaning media including media containing brightening agents.

It will be appreciated that the property of the markable yarn that a light emission * *. 20 characteristic may be attenuated may in some cases be a property that can be modified, within appropriate limits, to suit a required application. For example, a chemical composition of the markable yarn may be modified to suit a required application.

Furthermore, an intensity of visible light emitted by a markable yarn may be tailored (eg increased). This may be performed in order to ensure that contrast between laser irradiated and non laser-irradiated areas is visible to the naked eye even if the textile is washed with a cleaning medium containing a fluorescent dye to enhance an appearance of the textile. In other words, the light emission characteristics of the markable yarn still enable contrast to be seen with the naked eye between laser irradiated areas and non laser irradiated areas when the textile is viewed under ultraviolet light following washing in such a cleaning medium.

Preferably the markable yarn includes a markable dye.

A markable dye is a dye configured to be capable of dyeing a yarn thereby to form a markable yarn.

Preferably the markable dye comprises a fluorescent dye.

The fluorescent dye may comprise at least one selected from amongst umbelliferon and 7-hydroxycoumarin.

Preferably the markable yarn comprises at least one fibre.

For the present purposes, within the meaning of the term yarn' is included a strand comprising a single fibre, in addition to a strand comprising a plurality of fibres, such as a strand comprising a plurality of spun fibres.

The fluorescent dye may be provided on an outer surface of the fibre. * .

Alternatively or in addition, the fluorescent dye may be provided within the fibre. ****

Preferably the fibre is formed by co-extrusion of a melt, the melt comprising a plastics or polymeric material and a fluorescent dye.

*:*:, 20 A warp thread of the textile may comprise a markable yarn. * *

Alternatively or in addition a weft thread of the textile may comprise a markable yarn.

Preferably, the markable yarn is arranged such that the amount of visible light emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated only when said portion of the markable yarn has been exposed to an intensity of bleaching medium exceeding a critical intensity.

Preferably, the bleaching medium comprises ultraviolet radiation.

Preferably the bleaching medium comprises laser radiation.

In some embodiments of the invention another kind of radiation is employed, such as X-ray radiation or any other suitable kind of radiation. In some embodiments of the invention the bleaching medium is a chemical bleaching medium.

Preferably the markable yarn is arranged such that the amount of visible light emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated only when said portion of the markable yarn has been exposed to an intensity of laser radiation exceeding a critical intensity.

Preferably the laser radiation comprises ultraviolet laser radiation.

The laser radiation may have a wavelength in the range 255 to 360nm.

More preferably the laser radiation comprises laser radiation having a wavelength of 355nm.

The laser radiation may comprise radiation produced by a Nd:YAG laser. S. * *

Alternatively or in addition the bleaching medium may comprise ultraviolet radiation **S.

generated by a non-laser source. For example, the bleaching medium may comprise radiation generated by at least one selected from amongst a high intensity pressurised mercury lamp and an iron doped high intensity pressurised mercury lamp.

Preferably the method further comprises the step of providing masking means thereby to mask a portion of the textile from the bleaching medium.

The masking means may comprise an electronically configurable mask member.

The electronically configurable mask member may comprise a liquid crystal device.

This feature has the advantage that the mask may be changed electronically, without a need to physically replace one or more elements of the mask.

The masking means may comprise a fixed mask member and an electronically configurable mask member.

In a second aspect of the invention there is provided a label comprising a textile material, the textile material having at least a portion comprising a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, wherein the markable yarn is configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium.

Preferably the textile material comprises a fluorescent dye.

Preferably the bleaching medium comprises laser radiation.

Preferably the laser radiation comprises laser radiation having a wavelength of 355nm. * * ****

The laser radiation may comprises radiation produced by a Nd:YAG laser.

In a third aspect of the invention there is provided an article comprising a label according to the second aspect of the invention. * 20

In a fourth aspect of the invention there is provided a weaving loom having a warp or weft thread comprising a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, and wherein the markable yarn is configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium.

In a fifth aspect of the invention there is provided an apparatus for manufacturing a textile comprising: a weavipg loom according to the fourth aspect of the invention;and textile marking apparatus, the textile marking apparatus being configured to emit a bleaching medium thereby to expose a portion of the markable textile to the bleaching medium.

Preferably the textile marking apparatus further comprises area selection means for selecting an area of the markable textile to be exposed to the bleaching medium.

Preferably the area selection means comprises means for scanning a beam of the bleaching medium over a surface of the markable textile.

Alternatively or in addition the selection means may comprise masking means.

The masking means may comprise an electronically configurable mask member, the mask member being operable electronically to control an area of the markable textile to be irradiated by the bleaching medium.

The mask member may comprise a liquid crystal display panel (LCD). * I S...

The apparatus may comprise a mask member comprising a fixed mask for forming a logo on a textile and an electronic mask for forming a code on a textile. In some embodiments a laser scanning system is provided instead of or in addition to the electronic mask. The code may comprise one or more alphanumeric characters. * 20

The code may be different for each portion of textile exposed to the bleaching medium.

This feature has the advantage that articles may be provided with unique security or other codes. Alternatively or in addition, fabrication of articles with custom images, labels or other indicia may be provided, such as a person's name or a company name and/or logo.

In a sixth aspect of the invention there is provided a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, wherein the markable yarn is further configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium.

In a seventh aspect of the invention there is provided a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, wherein the markable yarn is further configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium, the markable yarn comprising a portion that has been exposed to the bleaching medium and a portion that has not been exposed to the bleaching medium.

In some embodiments the markable yarn is treated following exposure to the bleaching medium such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is not attenuated following exposure of the *::::* 15 portion of the markable yarn to a bleaching medium.

In an eighth seventh aspect of the invention there is provided a method of treating a ** markable yarn comprising the steps of: providing a markable yarn, the markable yarn * being configured to emit visible light when exposed to ultraviolet radiation, whereby the markable yarn is further configured such that the amount of visible radiation emitted by a **sss* . . . . * * portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and whereby, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium; and exposing a portion of the markable yarn to the bleaching medium.

Embodiments of the invention will now be described with reference to the accompanying figure in which: FIGURE 1 shows apparatus for manufacturing a label according to an embodiment of the invention.

According to a first embodiment of the invention a label 20 may be produced by apparatus 10 as shown in FIG. 1. The label 20 comprises a textile material 21 formed by weaving a weft thread 24 of markable yarn and a warp thread 22 of non-markable yarn. The apparatus 10 includes a laser scanning module 40. The laser scanning module 40 is employed to scan a laser beam across the textile material 21 as the textile material 21 is moved past the scanning module 40. The textile material 21 is then wound onto a drum 30. The laser scanning module 40 selectively exposes the textile material 21 to laser radiation by scanning a laser beam over the textile, producing a marking in the textile according to the requirements of the user.

Reference to markable yarn' according to the first embodiment of the invention is to a yarn comprising a markable yarn dye. A markable yarn has the property that portions that have not been exposed to a bleaching medium may be distinguished from portions that have been exposed to a bleaching medium. According to some embodiments of the invention the distinction may be readily made by optical inspection. According to the present embodiment, exposed and non-exposed portions of a markable yarn may be distinguished using the naked eye when a textile according to the first embodiment is ". 15 viewed under UV radiation.

In other words, in the case of a textile woven using markable yarn, visible contrast is * present between portions of the textile exposed to laser radiation, and portions of the * textile not exposed to laser radiation when the portions are viewed under UV light.

However, when the portions are viewed under visible light only and not UV light, contrast is not dscemable to the naked eye. It will be appreciated that in some embodiments of the invention contrast is discernible to the trained eye, such as that of a person trained to inspect textiles according to embodiments of the invention, but not to the untrained eye, such as that of a typical consumer.

According to the present invention, portions of the textile exposed to laser radiation become bleached'. That is, their capacity to emit visible light when exposed to ultraviolet radiation is attenuated. According to some embodiments of the invention their capacity to emit visible light is substantially destroyed following exposure to the bleaching medium. Thus, exposed and not exposed portions are distinguishable in that the exposed portion will appear to be emitting light, whilst the not exposed portion will not appear to be emitting light. Rather, the not-exposed portion will appear to be scattering light as opposed to emitting light.

According to the first embodiment the markable yarn dye includes umbelliferon. In alternative embodiments the markable yarn dye includes 7-hydroxycoumarin. In further embodiments, any other suitable markable yarn dye may be used, alone or in combination. In embodiments of the invention the markable yarn dye is a different dye, for which one or more optical properties may be modified by exposure to laser radiation.

In the case of umbelliferon and 7-hydroxycoumarin, irradiation by 355nm frequency tripled radiation from a Nd:YAG laser achieves a forced bleaching of the dye by disrupting active molecule groups. The disruption is caused by the high energy pulses produced by the laser. For umbelliferon, there are strong absorption points at 300, 305 and 325nm. Therefore laser radiation or other source of sufficiently intense ultraviolet radiation may be used having a frequency in the range 255 to 360nm.

Exposure of an area of textile comprising markable yarn to an amount of radiation sufficient to cause bleaching of the dye results in an area of the textile that appears dark when compared to areas of the textile not exposed to bleaching radiation, when the *. 15 textile is viewed by the naked eye under ultraviolet illumination conditions insufficient to S...

cause bleaching.

It will be appreciated that in many ambient environments ultraviolet (UV) light is present, * albeit often in very small amounts compared with an amount of visible light. For example, UV light may be present in a building due to leakage of sunlight into the building, or from illumination sources such as fluorescent lighting systems.

It will be understood that under such conditions emission of visible light by portions of a textile comprising markable yarn that have not been exposed to bleaching radiation may occur, due to irradiation by the ambient ultraviolet radiation. However, the markable yarn is configured such that the amount of visible radiation emitted by the markable yarn is small in comparison to the amount of visible (non-UV) light to which the textile would be exposed under normal lighting conditions. Thus, contrast between an area of the textile that has been subjected to bleaching radiation, and an area of the textile that has not been subjected to bleaching radiation, will not be visible to the untrained naked eye under normal ambient lighting conditions having a relatively low proportion of ultraviolet radiation.

However, it will be appreciated that in some embodiments of the invention the markable yarn may be configured to provide visible contrast even under ambient lighting conditions. For example, a textile comprising markable yarn may have a mark in the form of a decorative image or other motif marked thereon, the mark being visible under normal ambient lighting conditions (ie lighting conditions in which the illumination is predominantly visible light) in addition to UV lighting conditions (ie lighting conditions in which the illumination is predominantly UV radiation).

Markable yarn according to the present embodiment is produced by extrusion of a melt of plastics material mixed with markable yarn dye. The plastics material is a mixture of polypropylene and polyamide. In alternative embodiments the plastics material is polyester, polypropylene, or a mixture of any two or more of polypropylene, polyamide, polyester and polypropylene. In further embodiments the plastics material is any other suitable plastics material or combination of plastics materials.

In some embodiments of the invention, a markable yarn is fabricated by applying markable yarn dye to the surface of the fibre, e.g. to coat the fibre, instead of or in * 15 addition to forming the fibre from a melt of plastics material mixed with markable yarn dye.

Mixing of the markable yarn dye with the melt of plastics material before extrusion of a * fibre has the advantage that the markable yarn dye is present not only at the surface of the fibre, where it is vulnerable to abrasion and wear, but also within the fibre. Thus, as ****** . . * * the fibre wears, during use, fresh markable yarn dye is exposed. In embodiments of the invention markable yarn dye below the surface of the fibre experiences the same colour change as markable yarn dye at the surface of the fibre when the fibre is exposed to laser radiation. Therefore, as the fibre wears, the label is visible when irradiated by ultraviolet radiation.

In a preferred embodiment of the invention, a textile comprising the markable yarn is exposed to laser radiation using a Nd:YAG laser having a wavelength of substantially 355nm, in order to mark the textile. In alternative embodiments of the invention any suitable radiation source may be used. In some embodiments of the invention the markable yarn is configured to be marked by laser radiation from a carbon dioxide laser.

The laser scanning module 40 is configured to generate a laser beam and to scan the laser beam over a portion of the textile according to a user's instructions. This process results in the formation of a desired mark on the textile. The mark may be in the form of alphanumeric characters, an image, a barcode, or any other kind of mark or indicia, by suitable configuration of the laser scanning module 40.

In some embodiments if the invention the markable yarn is exposed to ultraviolet radiation from a source other than a laser. In some embodiments the source is a high intensity pressurized mercury lamp such as a mercury HQL lamp or iron doped mercury HQL lamp.

Following the process of weaving of the textile material 20, the textile material is wound onto a drum 30 for storage.

The use of a markable yarn has a number of advantages. For example, the markable yarn dye may be configured (as in the case of the present embodiment) such that significant bleaching of the markable yarn is unlikely to occur under ambient lighting . 15 conditions during normal use of the textile. *S*.

Thus, a markable yarn dye may be selected for which the illumination conditions required to effect bleaching of the dye will not normally be encountered during the useful * lifetime of the textile. A risk of unintentional marking of a textile comprising the markable-yarn, for example by exposure of the textile to sunlight, or other radiation * : sources commonly experienced by a textile, is thereby reduced.

The textile may be marked by a laser to form any suitable marking such as alphanumeric markings, barcode markings, or any other suitable markings.

A textile according to the present embodiment is formed with a weft thread of markable yarn. The weft thread is introduced only in regions where it is desirable to mark the textile using a laser. In some embodiments a weft thread of markable yarn is used throughout the textile material.

In alternative embodiments of the invention, a textile is formed with warp threads of markable yarn. In this case, the textile may be marked at substantially any location across a surface of the textile.

Embodiments of the invention have the advantage that a thread of markable yarn may be readily used as a replacement for a warp or weft thread of non-markable yarn that would otherwise be used to form the textile. Consequently, the thickness of the textile is not increased by incorporating a markable yarn into the textile instead of a non-markable yarn. This is in contrast to other labelling techniques in which an extra fibre is introduced into the textile in order to form a label. The extra fibre is typically of a different colour to the other fibres of the textile, in order to provide contrast between the extra fibre and the remaining fibres of the textile.

In some embodiments of the invention, the markable yarn is in fact woven into the textile in addition to the normal warp thread (of non-markable yarn) used to form the textile.

The textile is therefore of increased thickness in the region of the label.

In some embodiments of the invention, an alternative ultraviolet radiation source may be used to expose the textile to UV radiation instead of or in addition to laser radiation. For example, a source of UV radiation such as a mercury or iron doped mercury source may *. 15 be used. In some embodiments the source is used in combination with a mask. In some embodiments of the invention the mask is a liquid crystal device. Such a device has the advantage that a shape of an area to be exposedusing the mask is capable of being changed electronically. This has the advantage that a mark, such as * ,* alphanumeric characters, an image, a barcode or any other kind of mark, may be rapidly formed on a textile comprising markable yarn. The use of a masking technique as S.....

* * opposed to a beam-scanning technique such as a laser scanning technique has the advantage that marking of a textile material can often be performed more quickly.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", means "including but not limited to", and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein untess incompatible therewith. *. * . * .5S S... * . * S.. * S. S. S SS* S * * S. * . S * SS

*SSS5S

S S

Claims

CLAIMS: 1. A method of marking a textile comprising the steps of:

providing a textile having a portion comprising a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, whereby the markable yarn is further configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and whereby, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium; and exposing a portion of the textile to said bleaching medium thereby to attenuate an amount of visible radiation emitted by said portion when exposed to ultraviolet :

. radiation. *... * 15 * S*...CLME: *
2. A method as claimed in claim whereby the markable yarn includes a markable :.:. dye. *** *

* **
3. A method as claimed in claim 2 whereby the markable dye comprises a * 20 fluorescent dye.

****** * *
4. A method as claimed in claim 3 whereby the fluorescent dye comprises at least one selected from amongst umbelliferon and 7-hydroxycoumarin.
5. A method as claimed in claim 3 or claim 4 whereby the markable yarn comprises at least one fibre.
6. A method as claimed in claim 5 whereby the fluorescent dye is provided on an outer surface of the fibre.
7. A method as claimed in claim 5 or claim 6 whereby the fluorescent dye is provided within the fibre.
8. A method as claimed in claim 7 whereby the fibre is formed by co-extrusion of a melt, the melt comprising a plastics or polymeric material and the fluorescent dye.
9. A method as claimed in any preceding claim whereby a warp thread of the textile comprises the markable yarn.
10. A method as claimed in any preceding claim whereby a weft thread of the textile comprises the markable yarn.
11. A method as claimed in any preceding claim whereby the markable yarn is arranged such that the amount of visible light emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated only when said portion of the markable yarn has been exposed to an intensity of bleaching medium exceeding a critical intensity.
12. A method as claimed in any preceding claim whereby the bleaching medium comprises ultraviolet radiation. * .15 * .*.

*
13. A method as claimed in any preceding claim whereby the bleaching medium comprises laser radiation.

S

* **
14. A method as claimed in claim 13 whereby the laser radiation comprises laser radiation having a wavelength of 255 to 360nm.

**..*. * .
15. A method as claimed in claim 13 whereby the laser radiation comprises laser radiation having a wavelength of 355nm.
16. A method as claimed in any one of claims 13 to 15 whereby the laser radiation comprises radiation produced by a Nd:YAG laser.
17. A method as claimed in any one of claims 13 to 16 comprising the steps of scanning a beam of laser radiation over a portion of the textile.
18. A method as claimed in claim 12 whereby the bleaching medium comprises ultraviolet radiation generated by at least one selected from amongst a high intensity pressurised mercury lamp and an iron doped high intensity pressurised mercury lamp.
19. A method as claimed in any one of claims 1 to 11 whereby the bleaching medium comprises at least one selected from amongst X-ray radiation and a chemical.
20. A method as claimed in any preceding claim whereby the markable yarn is arranged such that the amount of visible light emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated only when said portion of the markable yarn has been exposed to an intensity of the bleaching medium exceeding a critical intensity.
21. A method as claimed in any preceding claim comprising the step of providing masking means thereby to mask a portion of the textile from the bleaching medium.
22. A method as claimed in claim 21 whereby the masking means comprises an electronically configurable mask member.

:...
23. A method as claimed in claim 22 whereby the electronically configurable mask ** 15 member comprises a liquid crystal device. * **

:.:
24. A method as claimed in claim 22 or claim 23 whereby the masking means comprises a fixed mask member and an electronically configurable mask member. * **

20
25. A method as claimed in claim 22 or claim 23 whereby the masking means * comprises a fixed mask member and a beam of laser radiation.
26. A label comprising a textile material, the textile material having at least a portion comprising a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, wherein the markable yarn is configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium.
27. A label as claimed in claim 26 wherein the textile comprises a fluorescent dye.
28. A label as claimed in claim 27 wherein the fluorescent dye comprises at least one selected from amongst umbelliferon and 7-hydroxycoumarin.
29. A label as claimed in any one of claims 26 to 28 wherein the bleaching medium comprises laser radiation.
30. A label as claimed in claim 29 wherein the laser radiation comprises laser radiation having a wavelength of 355nm.
31. A label as claimed in claim 29 or claim 30 wherein the laser radiation comprises radiation produced by a Nd:YAG laser.
32. An article comprising a label as claimed in any one of claims 26 to 31.
33. A weaving loom wherein a warp or weft thread comprises a markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, * 15 wherein the markable yarn is configured such that the amount of visible radiation emitted * by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated :.: * following exposure of the portion of the markable yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet * ** radiation, said portion is substantially indistinguishable using the naked eye from a 20 portion of the markable yarn that has not been exposed to the bleaching medium.

* ***.* * S
34. Apparatus for manufacturing a textile comprising: a weaving loom as claimed in claim 33; and textile marking apparatus, the textile marking apparatus being configured to emit a bleaching medium thereby to expose a portion of the markable textile to the bleaching medium.
35. Apparatus as claimed in claim 34 wherein the textile marking apparatus further comprises area selection means for selecting an area of the markable textile to be exposed to the bleaching medium.
36. Apparatus as claimed in claim 35 wherein the area selection means comprises means for scanning a beam of the bleaching medium over a surface of the markable textile.
37. Apparatus as claimed in claim 35 or claim 36 wherein the selection means comprises masking means.
38. Apparatus as claimed in claim 37 wherein the masking means comprises a mask member.
39. Apparatus as claimed in claim 38 wherein the mask member comprises an electronically configurable mask element, the electronically configurable mask element being operable by electronic means to control an area of the markable textile to be irradiated by the bleaching medium
40. Apparatus as claimed in claim 39 wherein the electronically configurable mask element comprises a liquid crystal display (LCD).

15
41. Apparatus as claimed in claim 39 or claim 40 wherein the electronically : * configurable mask element is operable to mask the bleaching medium thereby to form a code on a textile.

*:*::*
42. Apparatus as claimed in any one of claims 38 to 41 wherein the mask member further comprises a fixed mask for a forming a logo on a textile. * .
43. Apparatus as claimed in any one of claims 38 to 42 comprising laser scanning apparatus for forming a code on a textile.
44. Apparatus as claimed in claim 41 or claim 43 wherein the code comprises at least one selected from amongst one or more alphanumeric characters, a bar code and a block code.
45. A markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, wherein the markable yarn is further configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium.
46. A markable yarn, the markable yarn being configured to emit visible light when exposed to ultraviolet radiation, wherein the markable yarn is further configured such that the amount of visible radiation emitted by a portion of the markable yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and wherein, when the markable yarn is exposed to visible radiation and not to ultraviolet radiation, said portion is substantially indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium, the markable yarn comprising a portion that has been exposed to the bleaching medium and a portion that has not been exposed to the bleaching medium.
47. A method of treating a markable yarn comprising the steps of: providing a markable yarn, the markable yarn being configured to emit visible *...

light when exposed to ultraviolet radiation, whereby the markable yarn is further * configured such that the amount of visible radiation emitted by a portion of the markable :.: yarn when exposed to ultraviolet radiation is attenuated following exposure of the portion of the markable yarn to a bleaching medium, and whereby, when the rnarkable yarn is * ** exposed to visible radiation and not to ultraviolet radiation, said portion is substantially 20 indistinguishable using the naked eye from a portion of the markable yarn that has not been exposed to the bleaching medium; and exposing a portion of the markable yarn to the bleaching medium.
48. A method substantially as hereinbefore described with reference to the accompanying drawings.
49. A label substantially as hereinbefore described with reference to the accompanying drawings.
50. An article substantially as hereinbefore described with reference to the accompanying drawings.
51. A weaving loom substantially as hereinbefore described with reference to the accompanying drawings.
52. Apparatus for manufacturing a textile substantially as hereinbefore described with reference to the accompanying drawings.
53. A markable yarn substantially as hereinbefore described with reference to the accompanying drawings.
54. A method of treating a markable yarn substantially as hereinbefore described with reference to the accompanying drawings.

S * * * SS* S... * S * S* * .. * S S

SSS S

S *55 * S* * S * * S.

S

*555*S *