WO2009109923A1

WO2009109923A1 - A method of attaching a rfid tag to a cylindrical article, to a rfid tag-containing article, and to a rfid tag

Info

Publication number: WO2009109923A1
Application number: PCT/IB2009/050872
Authority: WO
Inventors: Hendrik Lodewyk Van Eeden; Marius Van Dyk; Louwrens Hermanus Du Toit
Original assignee: Ipico South Africa (Proprietary) Limited
Priority date: 2008-03-05
Filing date: 2009-03-04
Publication date: 2009-09-11

Abstract

This invention relates to a method of attaching an RFID tag (10) to a cylindrical article (20), an RFID tag-containing article (20) and an RFID tag (10). The method includes locating the RFID tag (10) in a continuous recess (22) in the cylindrical article (20). If the cylindrical article (20) is circular in cross-section and hollow, the method may include forming the recess (22) in either an outer surface or in an inner surface of the cylindrical article (20) so that the recess (22) is continuous and extends circumferentially.

Description

A method of attaching a RFID tag to a cylindrical article, to a RFID tag- containing article, and to a RFID tag

FIELD OF INVENTION

THIS INVENTION relates, broadly, to the identification of articles.

More particularly, the invention provides a method of attaching a RFID tag to a cylindrical article, to a RFID tag-containing article, and to a RFID tag.

BACKGROUND OF INVENTION

Radio frequency identification/inductive (RFID) systems, in which

RFID tags are attached to goods or articles for identifying such goods or articles throughout a supply chain of such goods or articles from manufacture thereof to end use, are known. Identification of goods or articles in this manner assists in inventory, process control and supply chain management thereof.

The Applicant is aware that in the paper, textile and related industries, there is a need to identify and track rolls of paper, textiles or yarns in the supply chain thereof, i.e. from a point of manufacture, e.g. a paper mill, to an end user, e.g. a newspaper printer, corrugator or bag plant, as well as for process control, e.g. to ensure that the right grade or type of paper is used during each step in a corrugation process. It is thus an object of this invention to provide a means whereby this can be achieved.

SUMMARY OF INVENTION

Thus, according to a first aspect of the invention, there is provided a method of attaching an RFID tag to a cylindrical article, the method including locating the RFID tag in a continuous recess in the cylindrical article.

In particular, the cylindrical article may be circular in cross-section and may be hollow. The method may include forming the recess in either an outer surface or in an inner surface of the cylindrical article so that the recess is continuous and extends circumferentially. The cylindrical article may be circular in cross-section, and may be hollow. The RFID tag may be continuous, it may be in the form of a ring or toroid, and it may be located concentrically within the recess.

The RFID tag may be a passive inductively coupled RFID tag, and preferably is a dual frequency (DF) tag or transponder, such as that described in WO 02/091290, which is hence incorporated herein by reference. It may thus comprise a module containing the tag electronics, and a strap fast with the module and containing an antenna, with the module and strap thus being continuous.

The method may include forming, e.g. cutting, the recess in the cylindrical object.

When the recess is an external circumferential recess in the outer surface of the article, the location of the RFID tag in the recess may be effected by winding a helical antenna of the tag directly into the recess.

In another embodiment of the invention, the recess is an external circumferential recess in the outer surface of the article, and the location of the RFID tag in the recess may be effected by sliding the continuous RFID tag, which is oversized with respect to the article, over the article until it is aligned with the recess, and then taking up slack in the RFID tag until the tag is located snugly within the recess. The slack may be taken up by urging a portion of the strap into a secondary recess which protrudes deeper into the article than the circumferential or primary recess. The secondary recess may be of elongate form and may extend transversely to the primary recess.

The portion of the tag strap in the secondary recess may be held in position by means of an elongate retaining member which fits snugly in the secondary recess. The continuous RFID tag may comprise a module containing tag electronics and a strap foil with the module and containing an antenna, with the module and strap thus being continuous, wherein the slack may be taken up by folding over a portion of the strap. In these embodiments of the invention, the plane in which the recess lies is preferably at right angles to the axis of the article.

However, in another embodiment of the invention, the plane in which the recess lies may be oblique relative to the axis of the article so that the recess is an elliptical recess, the footprint of the elliptical recess thus being greater than the footprint of a recess of the same width which lies in a plane which is at a right angle to the axis of the article. The oversized tag may be urged into the recess to fit snugly therein, with the slack in the tag thus being taken up by using the elliptical recess.

In yet another embodiment of the invention, the recess may be an external circumferential recess in the outer surface of the article, and the continuous RFID tag may comprise a module containing tag electronics and a strap foil with the module and containing an antenna. The tag module and strap may initially be separate from each other. The module may then be located in the recess, thereafter the strap may be located in the recess, and the end portion of the strap may be secured to the module, to form the complete RFID tag.

When the recess is an internal circumferential recess in the inner surface of the article, the location of the RFID tag in the recess may include sliding the tag in a deformed state into the hollow inside of the object until it is aligned with the recess, and then urging the deformed tag into a non- deformed state, thereby locating it in the recess.

The cylindrical article may be a core with layers of a flexible elongate element being wound onto the core once the RFID tag has been located in the core. - A -

In another embodiment of the invention, the cylindrical object may comprise a holder, such as a munitions holder.

The invention extends also to a cylindrical object to which has been attached a RFID tag by means of the method of the first aspect of the invention.

According to a second aspect of the invention, there is provided a RFID tag-containing article, which includes a cylindrical article having a continuous recess therein, and a RFID tag located within the recess.

The cylindrical article and RFID tag may be as hereinbefore described.

According to a third aspect of the invention, there is provided a

RFID tag, which comprises a module containing electronic components, and a strap fast with the module and containing at least one helically wound coil antenna, with a module and strap together defining a ring or toroidal-shaped tag body.

The electronics in the module may thus include components such as a RFID chip, a tuning capacitor, and a power supply capacitor.

Preferably, the strap may contain two helically wound coil antennas resonating at different frequencies, so that the RFID tag is thus a dual frequency (DF) tag.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described in more detail, by way of example, with reference to the accompanying diagrammatic drawings. In the drawings,

FIGURE 1 shows a three-dimensional view of a RFID tag in accordance with the invention;

FIGURE 2 shows an exploded three-dimensional view of a hollow core for a paper roll, fitted with the RFID tag of Figure 1 , in accordance with one embodiment of the invention;

FIGURE 3 shows a cross-sectional view through Ill-Ill in Figure 2, with the retaining member located in position in a secondary recess in the core;

FIGURE 4 shows a three-dimensional view of a core fitted with the RFID tag of Figure 1 , in accordance with another embodiment of the invention;

FIGURES 5 to 8 show sequential steps in attaching the RFID tag of Figure 1 , to a core, in accordance with yet another embodiment of the invention;

FIGURES 9 to 12 show sequential steps in attaching the RFID tag of Figure 1 , to a core in accordance with still another embodiment of the invention;

FIGURE 13 shows a three dimensional view of a core to which has been attached a different RFID tag;

FIGURE 14 shows, in part, a sectional view through XIV-XIV in Figure 13;

FIGURE 15 shows an enlarged view of a portion of the core of Figure 14;

FIGURES 16 to 18 show sequential steps in attaching a RFID tag, which is similar to that of Figure 1 , to a core, in accordance with another embodiment of the invention;

FIGURE 19 shows a side view of a container to which is attached a RFID tag, in accordance with the invention;

FIGURE 20 shows a longitudinal sectional view of the container of Figure 19; and FIGURE 21 shows an exploded three-dimensional view of the container of Figure 19. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to Figure 1 , reference numeral 10 generally indicates a dual frequency (DF) RFID tag. The tag 10 includes a ring or toroidal-shaped body 12 made up of a module 14 which contains tag electronics (not shown) such as a RFID chip, a tuning capacitor and a power supply capacitor, and, integral with the module 14, a strap 16 which consists of two helically wound coil antennas (not shown), one consisting of 50 to 300 turns resonating at 125 kHz and a second one consisting of 1 to 3 turns resonating at 6,8 MHz. In one embodiment of the invention, the strap 16 is flexible. However, in another embodiment of the invention, it is permanently deformable, e.g. pliable.

Referring to Figures 2 and 3, reference numeral 20 generally indicates a cylindrical article in the form of a circular section hollow cylindrical core used for forming rolls of paper, fabric, yarn or the like (not shown). The core 20 is typically of cardboard. A primary recess 22 is formed, e.g. cut, into the core 20. The recess 22 is a continuous recess which is provided in an outer surface of the core 20. The plane of the recess 22 is at right angles to the axis of the core 20. The recess 22 is thus a continuous circumferentially extending recess.

A secondary transverse recess 24 is also provided. The secondary recess 24 is deeper than the primary recess 22.

To fit the RFID tag 10 into the recess 22, the diameter of the RFID tag 10 is selected such that it can pass over the outer surface of the core 20.

In other words, the RFID tag 10 is slightly oversized relative to the core 20.

When the strap 16 of the tag 10 is aligned with the recess 22, the slack therein is taken up by urging a retaining member 26, such as a length of dowel, into the secondary recess 24, with the slack portion of the strap 16 thus also being urged into the secondary recess 24, as indicated most clearly in Figure 3. It will be appreciated that the dimensions of the RFID tag 10 and the dimensions of the recess 22 will be selected such that the tag 10 fits snugly into the recess 22 without it protruding above the outer surface of the core 20. Similarly, the dimensions of the retaining member 26 and the secondary recess 24 will be selected such that the retaining member 26 is held snugly within the recess 24.

The primary recess 22 is shallow, and is typically about 0.5mm deep. At the position at which it must accommodate the module 14 of the tag 10, it will be slightly deeper e.g. 1 mm deep. The secondary recess 24 will typically be somewhat deeper, e.g. about 5mm deep. It will be appreciated that instead of having only one secondary recess 24, a number of secondary recesses 24, spaced circumferentially apart, may be provided.

During the deformation of the strap 16 when the retaining member

26 is inserted into the secondary recess 24, i.e. during deformation of the tag antennas, the resonance of the tag antennas can change. The antennas will thus be pre-tuned so that the antennas achieve the desired resonance frequency after such deformation.

Once the RFID tag 10 has thus been attached to the core 20, layers of paper, fabric, yarn or the like (not shown) can be wound onto the core 20.

Referring to Figure 4, reference numeral 30 generally indicates a core to which has been fitted a RFID tag 10, in accordance with another embodiment of the invention.

Parts of the core and RFID tag which are the same or similar to those shown in Figures 1 to 3, are indicated with the same reference numerals. The RFID tag containing core 30 of Figure 4 is essentially the same as that shown in Figures 2 and 3; however, a protective sleeve 32 is provided around the tag 10 and retaining member 26. Referring to Figures 5 to 8, reference numeral 40 generally indicates a core to which is fitted a RFID tag 10, using another method of attachment of the RFID tag.

The core 40 is provided with a circumferential recess 42, which is similar to the recess 22 hereinbefore described with reference to Figures 2 and 3.

The tag 10 is located in the recess 42 by sliding it over the core until it is aligned with the recess 42. A portion 44 of the strap 16 (which is thus deformable) is then folded over as shown most clearly in Figures 6, 7 and 8 so as to take up the slack therein, until the tag 10 fits snugly in the recess 42.

Referring to Figures 9 to 12, reference numeral 50 generally indicates a core to which is attached a RFID tag 10, using a different method of attachment. A recess 52 is cut into the outer surface of the core 50 using a cutting tool 54 whose position in the direction of the length of the core, can be varied or adjusted. The recess 52 is similar to the recesses 22, 42 hereinbefore described as regards its width and depth; however, the recess 52 lies in a plane which is at an angle which is not a right angle (i.e. an oblique angle) to the axis of the core 50. In other words, the cutting tool 54 is, when the recess 52 is cut into the outer surface of the core, located at an angle which is diagonal to the axis of the core. The recess 52 is thus elliptically shape. Then, a portion of the recess 52 will be cut slightly deeper to accommodate the module 14 of the tag 10. When used with the core 50, the strap 16 of the tag 10 will be deformable, e.g. pliable. Thus, after the tag 10 has been fitted over the core 50, it is deformed into the recess 52, thereby taking up the slack in the tag 10. This is as a result of the footprint of the recess 52 being greater than would be the footprint of a similar recess which lies in a plane which is at right angles to the axis of the core. Referring to Figures 13 to 15, reference numeral 60 generally indicates a core to which is fitted a RFID tag, in accordance with another method of attachment.

The core 60 is provided with a recess 62 which is similar to the recesses 22, 42 hereinbefore described, i.e. the recess 62 lies in a plane which is at right angles to the axis of the core 60.

In this embodiment of the invention, a different RFID tag, generally indicated with reference numeral 64, is used. In the tag 64, its module 66 is separate from its strap 68. The module 68 contains the tag electronics on one side thereof, and the conductors on the other side, and is designed so that when the strap 68 is attached to it, the required helical antenna coils are formed.

The antenna strap 68 comprises conductors etched in an aluminium coating on a PET (polyethylene tetra-amine) base.

In this case, the module 66 is first located in a deeper portion 63 of the recess 62 and may be glued into position with the electronic components facing downwards. The strap 68 is then fitted tightly around the core 60 within the recess 62 and attached (connected) to the module 66 using anistropic conducting polymer or the like, as indicated at 69 in Figure 15.

It will be appreciated that, in a variation of this embodiment of the invention, it will be possible to manufacture the tag 64 with one end of the strap 68 already connected to, or integral with, the module 66, so that only one end of the strap 68 needs to be connected in situ when the tag 10 is fitted to the core.

Referring to Figures 16 to 18, reference numeral 70 generally indicates a core to which is fitted a RFID tag 10, using yet a different method of attachment. The core 70 is provided with an internal circumferential recess 72 which is also shallow, e.g. about 0.5mm deep and has a deeper portion, e.g. 1 mm deep, for accommodating the module of the tag 10. In this case, the module of the tag 10 will protrude outwardly. The tag 10 is selected so that its diameter is slightly greater than the internal diameter of the core 70. To fit the tag 10 into the recess 72, it is deformed, as indicated most clearly in Figure 17. It is then slid into the inside of the core until it is aligned with the recess 72 and then allowed to rebound elastically to its original shape so that it fits tightly into the recess 72. Alternatively, it can be expanded by means of compressed air or by other mechanical means, e.g. by inflating a balloon (not shown) located inside the tag.

As indicated hereinbefore, the cores shown in Figures 2 to 18 are typically used in paper, textile and related industries where layers of paper, fabric, yarn or the like are wound around the core after the RFID tag has been attached thereto, to form rolls of paper, textile or yarns. In these industries, there is a need to identify and track rolls from the manufacturer, e.g. a paper mill, to an end user (e.g. a newspaper printer, corrugator or bag plant) in the supply chain, as well as for process control, e.g. to ensure that the right grade or type of paper is used, e.g. during each of the steps in a corrugator plant.

The invention overcomes drawbacks associated with applying an electronic tag e.g. in the form of a smart label, to the wrapping of a roll of paper. The wrapping is usually the last step in the manufacture of the paper, and is the first thing to be removed at the end user. This implies that a tag applied to the outside wrapping is not present for process control either in the paper mill or at the end user or, for example, throughout a reverse supply chain, i.e. return of defective or incorrect products.

By means of the present invention, the RFID tag, snugly located in a recess, serves as a "birth certificate" since it is present from the start of the manufacturing process through to the end of life of the product, since the tag can be used during the supply chain of the core itself, as well as for the process of inventory control and supply chain management of the paper or textile wound onto the core.

Additionally, by locating the RFID tag in a recess in the core, certain problems are unexpectedly overcome:

• The material, yarn or paper that is wound onto the paper core can be RF absorbent, especially at higher frequencies (>10 MHz). The use of UHF tags is therefore problematic, as the absorption at UHF frequencies can be too high, leading to short reading ranges. Low frequencies, for example 125 kHz, 6.8 MHz, propagate well through paper, but these frequencies require inductively coupled tag antennas, typically helically wound coils, which are thus provided by the tags 10 hereinbefore described. • Paper rolls can be quite large in diameter, up to 2.5 m. Reading ranges in excess of 1 .5 m are required. Dual frequency technology is especially suitable for this kind of application since it operates at 125 kHz and 6.8. MHz, which propagates well through paper while achieving sufficiently long reading ranges. • When the tag is located in a recess in the core, damage to the tag on positioning the core over an axle, is avoided.

• A paper or textile core can be subject to very high pressures as the paper or textile is wound onto the core. By locating the RFID tag in a recess, damage to the paper by the tag, e.g. by leaving an indentation, is avoided. Likewise, damage to the tag by the paper due to the high pressures, is avoided.

• Since the RFID tags 10 are in the form of rings or toroids they are not rotation sensitive i.e. accurate readings are obtained even if the core rotates, since the reader does not change as the core rotates.

Referring to Figures 19 to 20, reference numeral 80 generally indicates a cylindrical munitions container to which is fitted a RFID tag 10. The container 80 is of cardboard or the like, and comprises a hollow cylindrical body portion 82 one end of which is closed off with an end cap 84. A spigot portion 86 protrudes axially from the other end of the body portion 82.

The container 80 includes a cap, generally indicated by reference numeral 88. The cap 88 includes a sleeve portion 90 and an end portion 92 closing off one end of the sleeve portion 90. The sleeve portion 90 fits snugly over the spigot portion 86 of the body portion 82, with a circumferential recess 94 being defined between the captive end of the spigot portion 86 and the free end of the sleeve portion.

A RFID tag 10 is located in the recess 94, and is thereby to be attached to the container.

By means of the RFID tag 10, the movement of the container 80 can be monitored in similar fashion to the movement of the cores hereinbefore described with reference to Figures 2 to 18.

Claims

1 . A method of attaching an RFID tag to a cylindrical article, the method including locating the RFID tag in a continuous recess in the cylindrical article.

2. The method according to claim 1 , wherein the cylindrical article is circular in cross-section and hollow, with the method including forming the recess in either an outer surface or in an inner surface of the cylindrical article so that the recess is continuous and extends circumferentially.

3. The method according to claim 2, wherein the RFID tag is continuous, being in the form of a ring or toroid, and is located concentrically within the recess.

4. The method according to claim 2 or claim 3, wherein the recess is an external circumferential recess in the outer surface of the article, with the location of the RFID tag in the recess being effected by winding a helical antenna of the tag directly into the recess.

5. The method according to claim 3, wherein the recess is an external circumferential recess in the outer surface of the article, and wherein the location of the RFID tag in the recess is effected by sliding the continuous RFID tag, which is oversized with respect to the article, over the article until it is aligned with the recess, and then taking up slack in the RFID tag until the tag is located snugly within the recess.

6. A method according to claim 5, wherein the continuous RFID tag comprises a module containing tag electronics and a strap fast with the module and containing an antenna, with the module and strap thus being continuous, with the slack being taken up by urging a portion of the strap into a secondary recess which protrudes deeper into the article than the circumferential or primary recess, the secondary recess being of elongate form and extending transversely to the primary recess.

7. The method according to claim 6, wherein the portion of the tag strap in the secondary recess is held in position by means of an elongate retaining member which fits snugly in the secondary recess.

8. The method according to claim 5, wherein the continuous RFID tag comprises a module containing tag electronics and a strap foil with the module and containing an antenna, with the module and strap thus being continuous, with the slack being taken up by folding over a portion of the strap.

9. The method according to claim 5, wherein the plane in which the recess lies is oblique relative to the axis of the article so that the recess is an elliptical recess, the footprint of the elliptical recess thus being greater than the footprint of a recess of the same width which lies in a plane which is at a right angle to the axis of the article, the method including urging the oversized tag into the recess to fit snugly therein, with slack in the tag thus being taken up by using the elliptical recess.

10. The method according to claim 2 or claim 3, wherein the recess is an external circumferential recess in the outer surface of the article, and wherein the continuous RFID tag comprises a module containing tag electronics and a strap foil with the module and containing an antenna, with the module and strap thus being continuous, with the tag module and strap initially being separate from each other, the method including locating the module in the recess, thereafter locating the strap in the recess, and then securing an end portion of the strap to the module, to form the complete RFID tag.

1 1 . The method according to claim 2 or claim 3, wherein the recess is an internal circumferential recess in the inner surface of the article, with the location of the RFID tag in the recess including sliding the tag in a deformed state into the hollow inside of the article until it is aligned with the recess, and then urging the deformed tag into a non-deformed state, thereby locating it in the recess.

12. The method according to any of claims 1 to 1 1 inclusive, wherein the cylindrical article is a core with layers of a flexible elongate element being wound onto the core once the RFID tag has been located in the core.

13. An RFID tag-containing article, which includes a cylindrical article having a continuous recess therein, and an RFID tag located within the recess.

14. An RFID tag, which comprises a module containing electronic components, and a strap fast with the module and containing at least one helically wound coil antenna, with a module and strap together defining a ring or toroidal-shaped tag body.