The invention relates to a coding for the purpose of textile, such as knit fabrics and woven fabrics, and non wovens, wherein the coding comprises a number of dots of ink, wherein the presence or absence of any of the ink dots indicates a particular code. The invention also relates to a method for applying and detecting such coding.

The coding of the type mentioned in the opening paragraph is known from Eurδpean patent application EP-A-0 328 226, which will be discussed in more detail hereinbelow.

During the production of textile or non wovens, i~ is particularly important for the planning of the production that it be known at any desired moment: where a particular production batch is located. Such production batch is usually rolled up into a roll, with the roll being displaced to the different processing stations. The processing operations can for instance consist in bleaching the production batch, providing a print, finishing the batch, and like operations. European patent application EP-A-0 328 226 discloses a coding for the purpose of textile, and a method and apparatus for applying such coding. The coding is detectable by means of electromagnetic induction resulting from the fact that the coding is built up from dots of iron-containing dye or adhesive. However, such iron-containing dye or adhesive has the particularly great drawback that during a bleaching

treatment of the textile, the iron brings about a catalytic reaction causing damage to the material. This damage can consist of weakening of the fibers and can even lead to the formation of holes in the material. This drawback is also inherent in other substances to be detected on the basis of induction, such as copper, nickel, cobalt, manganese and aluminum.

In another method known from practice for coding rolls of textile, the textile web is provided with a sticker provided with an optically readable code. However, such coding itself is damaged when the textile web is bleached, as a consequence of which, after bleaching, the ceding is no longer readable. Moreover, dying or printing the textile web is not possible, because this results in the coding becoming unreadable. Also, the sticker causes a local thickening, which complicates processing operations such as calendering.

To overcome these drawbacks, there is also known a coding method wherein a coded label is affixed to the rolls. Obviously, this involves the danger of the label coming loose from the roll, whereupon the traceability of the roll is lost. Moreover, for a roll whose label has disappeared it can no longer be established what operations that roll still has to undergo.

The object of the invention is to provide a coding for textile and/or non wovens of the type mentioned in the opening paragraph, without the above-described drawbacks.

To this end, according to the invention, the coding of the type mentioned in the opening paragraph is characterized in that the ink is of a highly quick-drying type, and is detectable even when the code is no longer visible due to the fact that the material has undergone a dying treatment or has been printed, with the ink or substances contained in that ink not entering into a catalytic reaction during the different treatments which the material undergoes during the production process. The major advantage of the coding according to the invention is that ink does not enter into a catalytic reaction during the different treatments which the material undergoes during the production process. Hence, the material retains the same quality everywhere, also at the location of the coding.

According to a further elaboration of the invention, precious metals are incorporated into the ink for the detectability thereof. Some precious metals, such as for instance silver, are electrically conductive and can hence influence an electromagnetic field, so that they are detectable by means of electromagnetic induction. Other precious metals that are not electrically conductive can in fact reflect or block microwaves, so that they are detectable by means of a microwave source/detector assembly. Suitable precious metals are for instance silver, platinum and gold. According to an alternative further elaboration of the invention, metal ions can be incorporated into the ink for

4

the purpose of the detectability, which metal ions by themselves have catalytic action during the treatment processes, wherein the catalytic action is however undone due to the fact that the metal ions are bonded in metal complexes or alloys or in a crystalline structure, so that no ions can be released during chemical reactions .

According to yet another further elaboration of the invention, the particles present in the ink for the purpose of detection can be closed off with a protective layer of, for instance, synthetic material. In this connection, one may for instance think of toner for copiers, wherein the carbon particles are enclosed by a binder material. Thus enclosed particles cannot enter into a catalytic reaction either during the treatment process. Inks of the above-mentioned type are indeed detectable without being visible, while the substances contained in the ink do not result in catalytic reactions during, in particular, the bleaching treatment of the material.

The invention also relates to a method for applying the coding according to the invention to a material web of textile and/or non wovens . The method is characterized in that a roll moves over a matrix of a number of inking pins movable into a first and a second position, so that a desired pattern of ink dots is transferred onto the roll, wherein the roll is then rolled along the material web, so that the ink dot pattern is transferred onto the material web. By means of

the method according to the invention, a coding is applied to a material web in an efficient and economical manner.

The invention also relates to a method for detecting a coding according to the invention applied to a material web, wherein a microwave source transmits microwaves to the material web at a position where the coding is applied, wherein the material web is moved along a number of microwave detectors in such a manner that the coding passes these microwave sensors, so that the microwaves reflected by the applied ink dots are detected by the microwave detectors, wherein a processing unit processes the signals provided by the microwave detectors and determines the coding.

It is understood that the microwave sensors can also be arranged on the side of the material web facing away from the microwave source. In that case, the detection takes place in that the blocking of microwaves is detected rather than the reflection of microwaves.

The invention also relates to an ink intended for applying a coding according to invention and to the use of such ink as coding.

Further elaborations of the invention are described in the subclaims and will be specified on the basis of an exemplary embodiment, with reference to the accompanying drawings . In these drawings: Fig. 1 shows an exemplary embodiment of a possible coding; and

Fig. 2 schematically shows an apparatus by means of which the method for applying the coding can be carried out, wherein in particular at step two, the textile web is shown on a reduced scale relative to the application roll. The exemplary embodiment shown in Fig. 1 of a coding for the purpose of textile or non wovens comprises a number of ink dots P, with the presence and/or absence of any of the ink dots P indicating a specific cede. According to the invention, the ink is of a highly quick-drying type and is detectable even when the code is no longer visible on account to the fact that the material has undergone a dying treatment or has been printed, because the ink contains a substance that reflects or blocks microwaves. Moreover, the ink or substances contained in that ink do not enter into a catalytic reaction during the different treatments which the material undergoes during the production process.

Preferably, the ink is a UV-hardening ink whose main constituents polymerize under the influence of UV-light, causing the ink to harden in a fraction of a second. As a consequence of this very short drying period, such an ink can be applied to a material web travelling at a high speed without involving the risk of the ink ending up on machine parts or on other parts of the material web during the further processing of the material web. Substances capable of reflecting or blocking microwaves can for instance be selected from the group consisting of

silver, gold and carbon. Preferably, these substances are mixed in particle form with the ink.

The exemplary embodiment shown in Fig. 1 of a coding comprises 49 ink dots P arranged in a square of 7 by 7 ink dots. With such coding, more than two billion (2 * 10 ³ ) codes can be formed. It is understood that more or fewer ink dots can be used as well and that they can be applied in different patterns .

The invention also relates to a method for applying a coding on a material web 4 of textile or non woven. The method is schematically shown in Figs. 1 and 2. In this method, a roll 1 is moved over a matrix 2 of a number of inking pins 3 movable into a first and a second position, so that a desired ink dot pattern is transferred onto the roll 1. The position of the ink pins 3 is controlled by a control. The inking pins 3 can for instance be excited electromagnetically. After the roll 1 has been inked, the roll is rolled along a material web 4, so that the ink dot pattern P is transferred from the roll 1 onto the material web 4. Preferably, after the ink dot pattern has been transferred onto the textile web 4 , the ink dot pattern is exposed to UV-light, causing the ink, preferably composed of constituents that polymerize under the influence of UV-light, to harden in a fraction of a second. By means of the method according to the invention, a coding can be applied to a textile web in an efficient and economical manner.

The invention also relates to a method for detecting a coding applied to a material web. According to the invention, this involves a microwave source transmitting microwaves to the material web 4 at a position where the coding has been applied. The material web 4 is moved along a number of microwave detectors in such a manner that the coding passes these microwave detectors, so that the microwaves reflected by the ink dots present are detected by the microwave detectors. The detectors are connected to a processing unit which processes the signals provided by the microwave detectors and which determines the coding. As indicated hereinabove, it is also possible that the microwave detectors are arranged on the side of the material web facing away from the microwave source, with the detectors detecting the interruption of the microwaves rather than the reflection of the microwaves.

It is,understood that the invention is not limited to the exemplary embodiment described, but that various modifications are possible within the framework of the invention. For instance, the term 'ink' should not be given a limited interpretation. Ink can also be a paste, dye, adhesive or a like quick-drying substance.

It is essential that use is made of a coding which blocks and/or reflects microwaves and that the coding does not contain substances that cause a catalytic reaction during one of the treatments of the material during the production process.