JPH09147251A - Commodity monitoring element, device and method for producing the element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a commodity monitoring element which excels in flexibility and can be applied to the commodities of various forms including the labels, etc. SOLUTION: A label 10 which is attached to a commodity, etc., includes a base material 11 consisting primarily of paper, synthetic resin, etc., and a commodity monitoring element 12 which is attached onto the material 11. The element 12 consists of an Fe-Si alloy wire 20 and a canceling magnetic layer 21 which covers the outer circumference part of the wire 20. The wire 20 is made of an Fe-Si alloy having the Si density of 6 to 7wt.% and has the sudden inversion of polarization when an alternating magnetic field exceeding its coercive force is applied. The layer 21 is made of a high polymer material 25 which is mixed with the electrically hard or semi-hard powder 26. The powder 26 applies a bias magnetic field to the wire 20 to prevent the inversion of magnetization of the wire when it is magnetized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article monitoring element used in a system for magnetically monitoring articles such as articles.

[0002]

2. Description of the Related Art A magnetic type article monitoring system uses a switchable magnetic element for a label or the like of an article.
Is provided, and a pulsed output due to magnetization reversal that occurs when an alternating magnetic field is applied to this magnetic sensitive element is detected by a coil or the like. Therefore, in this case, the passage of the article is monitored by providing the inspection gate with an alternating magnetic field generator and a detector for detecting a pulsed output due to the magnetization reversal. As the magnetic sensitive element, an element using an Fe-Co-Si-B based amorphous alloy, an Fe-Ni based alloy, or the like is known.

For example, when the above-described magnetic sensitive element is used to monitor a product in a store, the magnetic sensitive element is attached to the product, and when the product is settled, the magnetic sensitive device attached to the product is completed. It is necessary to perform a process of canceling the magnetization reversal function of the element, that is, a process of not generating a detection signal even when passing through the inspection gate.

From such a demand, it is proposed to provide a hard or semi-hard canceling magnetic body in the vicinity of the magnetic sensitive element, as in the prior art described in US Pat. No. 3,665,449. Has been done. In this prior art, like the article monitoring sign 1 shown in FIG. 11, a plate-shaped or wire-shaped canceling magnetic body 4 is arranged in the vicinity of the magnetic sensitive element 3 embedded in the base material 2. Then, the canceling magnetic body 4 is magnetized as necessary, and a bias magnetic field is applied to the magnetic sensitive element 3, so that the magnetic sensitive element 3 does not cause magnetization reversal even when an alternating magnetic field is applied to the inspection gate.

[0005]

In the marker 1 having the canceling function as in the above-mentioned prior art, since the canceling magnetic body 4 is arranged in the vicinity of the magnetic sensitive element 3, the marker 1 is less likely to bend, and the bottle 1 It is difficult to attach the marker 1 to a curved surface such as a can. Further, since the above-mentioned sign 1 is provided with the magnetic sensitive element 3 and the canceling magnetic body 4 side by side, it is inevitable to adopt a uniform form such as a label or a tape, and it is difficult to apply it to various forms of articles. Further, since the marker 1 has to be provided separately from the usual product label (trademark label or the like), the cost of the marker 1 is high.

Accordingly, the object of the present invention is to provide high flexibility,
Without being restricted to a uniform form like a label,
An object is to provide an article monitoring element that can be embedded in an article itself or a trademark label and the like, and a manufacturing apparatus and a manufacturing method that can reduce costs.

[0007]

The article monitoring element of the present invention developed to achieve the above object has a Si concentration of 6 or less.
Fe which consists of ~ 7wt% Fe-Si alloy and causes abrupt magnetization reversal when an alternating magnetic field exceeding its coercive force is applied
-Si alloy wire and magnetically hard or semi-hard magnetic powder are mixed in the polymer material to cover the outer circumference of the Fe-Si alloy wire and to magnetize the alloy wire when the magnetic powder is magnetized. And a canceling magnetic layer that applies a bias magnetic field that blocks magnetization reversal to the alloy wire. Fe-S above
It is recommended that the i alloy wire has an absolute value of saturation magnetostriction of 30 × 10 ⁻⁶ or less.

In the above article monitoring element, when an alternating magnetic field exceeding the coercive force of the Fe--Si alloy wire is applied, the large Barkhausen effect (large Barkhausen jump) causes a sharp magnetization reversal with almost no magnetostriction. Cause Therefore, when an alternating magnetic field exceeding the coercive force of the Fe-Si alloy wire is applied to the inspection gate or the like, a sharp magnetization reversal occurs in the Fe-Si alloy wire. By detecting the magnetic field change accompanying this magnetization reversal with a detector such as a detection coil,
A pulsed output is detected. By comparing the pulsed output with predetermined reference data or the like, it is possible to determine whether or not this element is magnetized, that is, whether or not a bias magnetic field is applied to the Fe-Si alloy wire. You can

If the bias magnetic field is applied to the Fe--Si alloy wire by magnetizing the canceling magnetic layer as needed, the magnetization reversal of the Fe--Si alloy wire can be prevented. In this case, the magnetization reversal function of the alloy wire is canceled, and the pulsed output is no longer detected even when an alternating magnetic field is applied to the inspection gate or the like. This Fe-
Since the Si alloy wire hardly causes magnetostriction at the time of magnetization reversal, even if it is fixed to a label or the like, the output is not affected. On the other hand, the amorphous ferromagnetic wire and Fe-Ni alloy wire used for the conventional label for shoplifting have a large magnetostriction, so if they are fixed to the label, the output will drop drastically or the output will decrease. You will not be able to get it.

According to a third aspect of the manufacturing apparatus for manufacturing the article monitoring element of the present invention, a magnetic layer material obtained by mixing magnetically hard or semi-hard magnetic powder into an uncured polymer material is used. A container for containing and Fe- with a Si concentration of 6 to 7 wt%
A supply mechanism for continuously sending out an Fe-Si alloy wire made of a Si alloy, and an uncured magnetic layer material having an inner diameter capable of inserting the Fe-Si alloy wire and communicating with the container and the alloy being the alloy. A nozzle that continuously draws out the alloy wire while discharging to the outer peripheral side of the wire, and the magnetic layer material by cooling and hardening the magnetic layer material that adheres to the outer circumference of the alloy wire that exits from the nozzle A cooling means for fixing the canceling magnetic layer consisting of the above to the alloy wire, and a winding mechanism for winding up the alloy wire on which the canceling magnetic layer is fixed.

According to a fifth aspect of the present invention, there is provided a manufacturing apparatus, wherein a container for containing a magnetic layer material in which magnetically hard or semi-hard magnetic powder is dissolved in a solvent together with a polymer material, and Fe-
A feeding mechanism for continuously feeding the Si alloy wire, and the above Fe-
A nozzle having an inner diameter capable of inserting a Si alloy wire and communicating with the container for continuously leading out the alloy wire while discharging the magnetic layer material to the outer peripheral side of the alloy wire; Further, a drying means for fixing the canceling magnetic layer made of the magnetic layer material to the alloy wire by drying and curing the magnetic layer material attached to the outer circumference of the alloy wire is provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. In an example of the label-like sign 10 shown in FIGS. 1 and 2, an article monitoring element 12 is embedded in a strip-shaped base material 11 made of a non-magnetic material such as paper or synthetic resin. The element 12 does not necessarily have to be provided at the center of the base material 11 in the width direction, and may be provided at a position closer to one side. As the material of the base material 11, a non-conductive material such as glass or ceramics can be used in addition to paper or synthetic resin.

The sign 10 is preferably provided with an adhesive layer 13 on the back side of the substrate 11 so that it can be attached to an article. However, in the case of a hanging tag such as a tag, the adhesive layer 13 can be omitted. A transparent or opaque protective layer 14 may be provided on the front surface side of the base material 11. Further, like the mark 10 shown in FIG. 3, the optically readable product information 17 such as the product identification barcode 15 and the price display 16 may be printed.

As shown in FIG. 1, the article monitoring element 12 includes:
Fe-Si alloy wire 20 located in the central portion of the element 12
And a canceling magnetic layer 21 that covers the entire outer circumference of the alloy wire 20, and a fixed layer 22 made of a polymer material that covers the entire outer circumference of the magnetic layer 21. The outer diameter of the element 12 is preferably about 40 to 500 μm. The length of the element 12 is about 100 to 1000 times the diameter of the Fe—Si alloy wire 20. The canceling magnetic layer 21 is made of a polymer material 25.
In addition, the following magnetic powder 26 is mixed.

The Fe--Si alloy wire 20 has a Si concentration of 6 to 6.
7 wt% (more preferably 6.2 to 6.7 wt%) Fe
-Si alloy is used. The alloy wire 20 has a diameter of 3
It is recommended that the length is 0 to 150 μm (for example, around 50 μm) and the length is 300 to 1000 times the wire diameter (for example, around 40 mm). This alloy wire 20 has a saturation magnetic flux density of about 1.2 to 2.0 times that of an amorphous alloy wire (amorphous wire). The alloy wire 20 preferably has a circular cross section, but may have a cross section other than a circle, such as an ellipse, a polygon, or a rectangle.

The Fe-Si alloy wire 20 has a strong magnetic anisotropy in the axial direction due to the magnetic effect of its shape and crystal structure, and the coercive force of the alloy wire 20 (for example, 0.1 to 1. When an alternating magnetic field with an amplitude larger than 0 Oersted is applied, a very steep reversal of magnetization occurs due to the large Barkhausen effect.

When this magnetization reversal is detected by, for example, a solenoid coil, a pulsed output P as shown in FIG.
Is obtained. That is, when the positive coercive force of the Fe-Si alloy wire 20 is Hp and the negative coercive force thereof is -Hp, the Fe-Si alloy wire 20 has the moment when the alternating magnetic field exceeds these coercive forces Hp and -Hp.
Magnetization reversal occurs in the alloy wire 20, and a pulsed output voltage P corresponding to this magnetization reversal is detected. Since the width of this pulse is as small as 10 to 100 μsec, the output voltage contains many high frequency components of several KHz or more. The magnetization reversal hardly depends on the frequency of the alternating magnetic field applied,
Even if the frequency is low, the same pulsed output P can be obtained.

The canceling magnetic layer 21 is made of the polymer material 2
5 is mixed with a large number of magnetic powders 26 made of a magnetically hard or semi-hard substance. The polymer material 25 of the magnetic layer 21 is preferably of the same type as the polymer material of the pinned layer 22. As a material of the magnetic powder 26,
For example, γ with a coercive force of about 100 to 5000 Oersted
-Fe ₂ O ₃ or _{Co-γ-Fe 2 O 3} , Fe 3 O 4, B
Ferromagnetic materials including various ferrites such as a ferrite and Sr ferrite are suitable. The magnetic powder 26
Is preferably processed to have a particle size of 0.2 μm to 1.6 μm. The volume ratio of the polymer material 25 and the magnetic powder 26 is preferably in the range of about 1: 2 to 3: 1.

When the magnetic powder 26 is magnetized, Fe
A bias magnetic field can be applied to the -Si alloy wire 20. In the case of FIG. 4, as shown by the chain double-dashed line S, the alternating magnetic field acting on the Fe—Si alloy wire 20 shifts above the coercive force (−Hp) by the bias magnetic field, so that the magnetization reversal does not occur and the pulse shape is generated. The output P of is also not generated.

To manufacture the element 12, the Fe--Si alloy wire 20 is passed through a resin tank containing the material of the canceling magnetic layer 21 (uncured liquid polymer material mixed with magnetic powder 26). It is possible to adopt a process in which the above material is adhered to the outer circumference of the alloy wire 20 and then the material is cured.

Further, the element 12 can be continuously manufactured by using the manufacturing apparatus 30 shown in FIG. The manufacturing apparatus 30 includes a container 31, a supply mechanism 32 that continuously feeds the Fe—Si alloy wire 20, a nozzle 33, a cooling unit 34, and a winding mechanism 35.

The container 31 has an inner chamber 31a and an outer chamber 31b, and the material of the canceling magnetic layer 21, that is, the magnetic layer material 21a in which the magnetic powder 26 is mixed with the uncured polymer material is contained in the inner chamber 31a. ing. The inner nozzle portion 33a communicates with the inner chamber 31a, and the inner nozzle portion 33a
The magnetic layer material 21a is discharged from a to the outer peripheral side of the Fe—Si alloy wire 20. Therefore, the inner nozzle portion 33a has an inner diameter that allows the Fe-Si alloy wire 20 to be inserted therethrough, and the alloy wire 20 is continuously drawn out together with the magnetic layer material 21a.

In the outer chamber 31b, as the material of the fixing layer 22, for example, a polymer material 22a which is liquefied by being heated to 150 ° C. to 500 ° C. is accommodated. The outer nozzle portion 33b communicates with the outer chamber 31b, and the polymer material 22a is discharged from the outer nozzle portion 33a to the outer peripheral side of the canceling magnetic layer 21.

The supply mechanism 32 is adapted to continuously feed the Fe--Si alloy wire 20 wound around the reel 37 or the like toward the center of the nozzle 33. The winding mechanism 35 has a reel 38 that is rotated by a motor (not shown),
The element 12 coming out of the nozzle 33 is wound by the reel 38.

The cooling means 34 has a function of cooling the magnetic layer material 21a and the polymer material 22a of the pinned layer 22 which are ejected from the nozzle 33 and adhered to the outer periphery of the alloy wire 20. The cooling means 34 in the illustrated example cools the materials 21 a and 22 a with air outside the nozzle 33. However,
The low temperature fluid may be forced on the materials 21a and 22a adhered to the outer periphery of the alloy wire 20 to forcibly cool them.

In the manufacturing apparatus 30, the materials 21a and 22a are dropped from a nozzle 33 provided at the bottom of the container 31 or pressure is applied to the materials 21a and 22a.
Is ejected from the nozzle 33, and at the same time, the Fe—Si alloy wire 20 is pulled out below the nozzle 33. And material 21
By a and 22a coming out of the nozzle 33 and solidifying,
The Fe—Si alloy wire 20, the canceling magnetic layer 21 and the pinned layer 22 are integrated with each other. In this case, the material 21
a, 22a is discharged from the nozzle 33, and Fe-S
The element 12 having a more uniform magnetic layer 21 and pinned layer 22 can be obtained by tuning the speed at which the i alloy wire 20 is pulled out.

Incidentally, as in the article monitoring element 12 shown in FIG. 6, the outer circumference of the Fe--Si alloy wire 20 may be coated with a canceling magnetic layer 21 which also serves as a fixed layer.
In order to manufacture this element 12, the manufacturing apparatus 30 shown in FIG.
As described above, the magnetic layer material 21a in which the fixing polymer material and the magnetic powder 26 are mixed is housed in the container 31 in advance, and the Fe-Si alloy wire 20 is pulled out while discharging the material 21a from the nozzle 33. Thus, the element 12 shown in FIG. 6 can be obtained.

The cross-sectional shape of the element 12 can be changed according to the cross-sectional shape of the nozzle 33. The element 12 wound on the reel 38 is cut into a desired length by a cutter in a cutting step (not shown).

The article monitoring element 12 can be manufactured by the manufacturing apparatus 30 shown in FIG. The manufacturing apparatus 30 shown in FIG. 8 includes a container 31, a supply mechanism 32 for continuously feeding the Fe—Si alloy wire 20, a nozzle 33, a drying means 34 ′, and a winding mechanism 35. In this case, the container 31 contains the magnetic material 21a 'in which the polymer material for fixing and the magnetic powder 26 are dissolved in a solvent in advance, and the nozzle 3
Fe-Si alloy wire 2 while discharging material 21a 'from 3
Pull out 0. The material 21a 'may be fixed by air drying, but the solvent may be forcibly evaporated by the drying means 34'. Other configurations and operations are similar to those of the embodiment shown in FIG. 5 or 7.

FIG. 9 shows an article (commodity) with a mark 10.
An inspection gate 40 for monitoring the passage of M is shown. The gate 40 includes a transmitter 42 as a magnetic field applying unit that generates an alternating magnetic field in an inspection area 41 through which a customer passes, and a receiver 43 as a receiving unit that outputs a change in the magnetic field in the inspection area 41 as an output signal. I have.

The transmitter 42 has a transmitting coil 45 and an AC generator 47 for supplying an alternating current to the transmitting coil 45 via an amplifier 46. The transmitting coil 45 generates an alternating magnetic field according to the alternating current supplied from the alternating current generator 47 via the amplifier 46, and applies the alternating magnetic field to the inspection region 41.

The receiver 43 includes a detection coil 50 that functions as an electromagnetic induction coil, and a detection circuit 51 connected to the detection coil 50. The detection coil 50 is disposed facing the transmitting coil 45 at an interval enough to allow a person to pass through, for example, at an interval of 1 m, and forms the inspection area 41 between the detecting coil 50 and the transmitting coil 45. Then, a current corresponding to the magnetic field in the inspection region 41 is induced in the detection coil 50 forming the receiving means, and this current is output to the detection circuit 51 as an output signal.

The detection circuit 51 includes a filter 52 connected to the detection coil 50, an amplifier 53, and a comparator 54. The filter 52 extracts the high frequency component of the pulsed output signal resulting from the sharp magnetization reversal of the Fe—Si alloy wire 20 from the output signal received by the detection coil 50. Since the pulsed output periodically appears every time the positive and negative of the alternating magnetic field changes, the detection is performed almost in an instant without moving the article M with the mark 10 relative to the alternating magnetic field.

The comparator 54 compares the detected pulsed output with reference data prepared in advance,
Whether a pulsed output is generated (Fe-Si alloy wire 20
Whether or not the magnetization reversal has occurred), that is, whether or not the canceling magnetic layer 21 is magnetized. Article M
When passing through the gate 40, the canceling magnetic layer 21
If the magnetic field is not magnetized, the receiver 43 and the detection circuit 51 detect a pulsed output.

An informing means 56 is connected to the comparator 54 via a drive section 55. The drive unit 55 activates the notification unit 56 according to the comparison result of the comparator 54. The notifying means 56 notifies the administrator (a clerk or the like) of the gate 40 of the collation result by a display means such as a warning light or a notification sound.

Next, the operation of the marker 10 having the above structure will be described. Signs 10 to monitor goods at shops and the like
When using the mark, the marker 10 is attached to the product in advance. In addition, the inspection gate 40 is installed at the exit of the store, for example, at the exit of a checkout station (so-called cash register). A magnetic field generator (not shown) for magnetizing the canceling magnetic layer 21 is provided at the checkout place. When the customer pays for the product at the checkout place, the magnetic field for cancellation 21 of the sign 10 attached to the product is magnetized by the magnetic field generator.

For this reason, the products that have already been paid for are the inspection gates 4.
As the Fe—Si alloy wire 20 does not undergo magnetization reversal when passing through 0, this product is allowed to exit the inspection gate 40. In contrast, unchecked products are inspection gate 4
When passing through 0, the Fe—Si alloy wire 20 of the mark 10 attached to the product causes magnetization reversal. Therefore, a pulse-like output is detected by the coil 50, and the detection circuit 51 operates the notification unit 56 via the drive unit 55.

As in the above embodiment, the Fe--Si alloy wire 20 is used.
Since the canceling magnetic layer 21 is integrated with the element 12, the element 12 is placed under the mark 10 which also serves as a trademark label in the process of manufacturing the article M, for example, the article M shown in FIGS. It can be provided, and the cost can be reduced as compared with the conventional magnetic article surveillance sign. Further, the element 12 can be added to the article in various forms, such as by directly scraping the element 12 on paper or by forming it into a label shape as in the past.

Since the Fe-Si alloy wire 20 is extremely thin and flexible, it can be easily attached not only to an article having a flat surface but also to an article having a curved surface such as a bottle or a can. For example, as shown in FIG.
It can also be provided in a curved state along the curved surface of the article M. Since conventional amorphous ferromagnetic wires and Fe-Ni alloy wires have large magnetostriction, the output will be reduced if they are provided in a curved state. Further, the element 12 of the present invention can be embedded in the article itself to be monitored (for example, paper or a synthetic resin case).

[0040]

According to the present invention, the magnetic powder for canceling the magnetization reversal function of the Fe-Si alloy wire is coated on the outer circumference of the alloy wire to make the whole element linear, so that the Fe-S alloy wire is formed.
The i alloy wire is extremely thin and flexible,
It does not impair the flexibility of the article monitoring element and can be easily attached not only to articles having a flat surface but also to articles having a curved surface such as bottles and cans. The form of the sign having the article monitoring element does not have to be a label, and can take various forms such as being easily sandwiched between the article and the trademark label and being easily embedded in the article or the label. And can be implemented at low cost.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a sign including an article monitoring element according to an embodiment of the present invention.

FIG. 2 is a perspective view of the sign shown in FIG.

FIG. 3 is a plan view showing a modified example of a sign including an article monitoring element.

4 is a diagram showing the relationship between the excitation magnetic field and the output of the marker shown in FIG.

FIG. 5 is a schematic view showing an apparatus for manufacturing an article monitoring element.

FIG. 6 is a partial cross-sectional view of a sign including an article monitoring element according to another embodiment of the present invention.

FIG. 7 is a schematic view showing an apparatus for manufacturing the article monitoring element shown in FIG.

FIG. 8 is a schematic view showing a modification of the apparatus for manufacturing the article monitoring element shown in FIG.

FIG. 9 is a perspective view showing a configuration of an inspection gate that detects an article monitoring element.

FIG. 10 is a perspective view of an article provided with a sign.

FIG. 11 is a plan view of a conventional sign having a canceling magnetic material.

[Explanation of symbols]

 10 ... Marker 11 ... Base material 12 ... Article monitoring element 20 ... Fe-Si alloy wire 21 ... Canceling magnetic layer 22 ... Fixing layer 25 ... Polymer material 26 ... Magnetic powder

Claims (7)

[Claims] 1. An Fe--Si alloy wire made of an Fe--Si alloy having a Si concentration of 6 to 7 wt% and having a sharp magnetization reversal when an alternating magnetic field exceeding its coercive force is applied, and a magnetically hard or semi-magnetic wire. A bias magnetic field is applied to the alloy wire when hard magnetic powder is mixed in the polymer material to cover the outer circumference of the Fe-Si alloy wire and to prevent the reversal of magnetization of the alloy wire when the magnetic powder is magnetized. A linear article monitoring element, comprising: a canceling magnetic layer to be given. 2. The article monitoring element according to claim 1, wherein the canceling magnetic layer is further covered with a fixing layer made of a polymer material on the outer periphery thereof. 3. A container for accommodating a magnetic layer material in which magnetically hard or semi-hard magnetic powder is mixed in an uncured polymer material, and an Fe--Si alloy having a Si concentration of 6 to 7 wt%. A supply mechanism for continuously sending out an Fe-Si alloy wire that causes a sharp magnetization reversal when an alternating magnetic field exceeding a coercive force is applied, and an inner diameter capable of inserting the Fe-Si alloy wire and communicating with the container. The nozzle that continuously draws out the alloy wire while discharging the uncured magnetic layer material to the outer peripheral side of the alloy wire, and the magnetic material that adheres to the outer circumference of the alloy wire that exits from the nozzle Cooling means for fixing the canceling magnetic layer made of the magnetic layer material to the alloy wire by cooling and hardening the layer material; and a winding mechanism for winding the alloy wire having the canceling magnetic layer fixed thereto. What you have An apparatus for manufacturing an article monitoring element, comprising: 4. The nozzle comprises the magnetic layer material and the Fe layer.
4. An inner nozzle portion for discharging to the outer peripheral side of the —Si alloy wire, and an outer nozzle portion for discharging the polymer material for the pinned layer on the outer peripheral side of the magnetic layer material. An apparatus for manufacturing the above described article monitoring element. 5. A container containing a magnetically hard or semi-hard magnetic powder and a magnetic layer material in which a polymer material is dissolved in a solvent, and a coercive force made of a Fe--Si alloy having a Si concentration of 6 to 7 wt%. A feeding mechanism for continuously sending out a Fe—Si alloy wire that causes a sharp magnetization reversal when an alternating magnetic field exceeding 100 μm is applied, and has an inner diameter capable of inserting the Fe—Si alloy wire and communicates with the container. The magnetic layer material is continuously discharged while ejecting the magnetic layer material to the outer peripheral side of the alloy wire, and the magnetic layer material adhering to the outer periphery of the alloy wire ejected from the nozzle is dried. A drying unit that fixes the canceling magnetic layer made of the magnetic layer material to the alloy wire by curing, and a winding mechanism that winds up the alloy wire having the canceling magnetic layer fixed thereto. To Equipment for manufacturing item monitoring devices. 6. An Fe—Si alloy wire made of an Fe—Si alloy having a Si concentration of 6 to 7 wt% and having a sharp magnetization reversal when an alternating magnetic field exceeding its coercive force is applied, is continuously drawn out from a nozzle. The magnetic layer material on the outer circumference of the alloy wire by discharging the magnetic layer material in which magnetic hard or semi-hard magnetic powder is mixed in an uncured polymer material from the nozzle to the outer circumference side of the alloy wire. And a step of fixing the canceling magnetic layer made of the magnetic layer material to the alloy wire by cooling and curing the magnetic layer material applied to the alloy wire, and the canceling magnetic layer is An article monitoring element comprising: a step of winding the fixed Fe-Si alloy wire; and a step of cutting the fixed Fe-Si alloy wire into a predetermined length. Manufacturing method. 7. An Fe—Si alloy wire made of an Fe—Si alloy having a Si concentration of 6 to 7 wt% and having a sharp magnetization reversal when an alternating magnetic field exceeding its coercive force is applied, is continuously drawn out from a nozzle. The magnetic layer material is applied to the outer periphery of the alloy wire by discharging the magnetic layer material obtained by dissolving magnetically hard or semi-hard magnetic powder and a polymer material in a solvent to the outer peripheral side of the alloy wire from the nozzle. And a step of fixing the canceling magnetic layer made of the magnetic layer material to the alloy wire by drying and curing the magnetic layer material applied to the alloy wire, and the canceling magnetic layer being fixed A step of winding the Fe-Si alloy wire, and a step of cutting the Fe-Si alloy wire, to which the magnetic layer is fixed, into a predetermined length. Method.