Production of a planar magnetized structure

Abstract

The invention relates to a method (100) for producing a planar magnetized structure (1a) having two opposite sides (2a, 3a) with different magnetic polarities. It is proposed to roll up or fold a magnetizable structure (1) in a specific manner prior to the magnetization process.

Description

[0001] Description

[0002] Production of a planar magnetized structure

[0003] The present invention relates to a method for producing a planar magnetized structure with two opposing sides of opposite magnetic polarity. The invention also relates to a method for producing a multilayer composite article possessing sensory functionality.

[0004] Such structures are used, for example, as detection strips in drive belts for position or cycle determination, or as parts of a crack detection sensor in conveyor belts.

[0005] Flat magnetized structures can be produced, for example, by printing a magnetizable paste or ink flatly or in a structured pattern onto a thin substrate film and then curing it to form a magnetizable layer or structure. For the necessary magnetic functionality, the printed magnetizable material must be magnetized or polarized homogeneously along a predetermined direction parallel to the surface of the substrate film. Different magnetic poles are thus formed on the sides of the magnetized structure that are spaced apart from each other along the magnetization direction. An example of a suitable magnetizable material is described in EP 4269510 A1.

[0006] For the sensory functionality of the magnetized structure, it is advantageous if it has the highest possible magnetic remanence.

[0007] exhibits remanent flux density. To achieve the highest possible remanence, a strong external magnetic field is required for magnetization. This magnetic field is generated by a magnetizing device, which contains a powerful coil forming a substantially cylindrical magnetization chamber within its interior. A homogeneous magnetic field can be generated within this magnetization chamber, the field direction of which is essentially perpendicular to the cross-section of the magnetization chamber. Magnetizing devices are expensive to purchase and operate, with the costs scaling disproportionately with the desired cross-section of the magnetization chamber. Due to the design-dependent field direction, the cross-section of the magnetization chamber determines the maximum length of the polarized sides.The substrate plates with magnetizable structures applied to them must therefore be prepared in such a way that they fit into the magnetization space before they can be positioned and magnetized in it.

[0008] The object of the present invention is to provide a method for producing a planar magnetized structure with two opposing, differently magnetically polarized sides, in which the dependence of the maximum length of the polarized sides on the design characteristics of the magnetization device is reduced. In particular, the method should enable the production of a magnetized structure in which the maximum length of the polarized sides is greater than the width or diameter of the available cross-section of the magnetization space.

[0009] This problem is solved by a method comprising the features of claim 1. Preferred features are the subject of the dependent claims.

[0010] Further advantages and features can be found in the general description and the examples of implementation.

[0011] The inventive method for producing a planar magnetized structure with two opposing sides of opposite magnetic polarity comprises the following steps:

[0012] Providing a magnetizable structure comprising a flexible substrate plate on which a magnetizable material is arranged, in particular printed;

[0013] Rolling and / or folding the magnetizable structure; and magnetizing the rolled or folded magnetizable structure. The invention is based on the idea of ​​reducing the external dimensions of the magnetizable structure so that magnetization can be carried out in a smaller magnetization space. By rolling the magnetizable structure, its external dimensions can be efficiently reduced without excessively compressing or stretching the magnetic material. Folding, particularly in a zigzag or meandering pattern, allows the magnetizable structure to be folded in a particularly compact manner. Folding the magnetizable structure along one or more fold lines can be done with or without the formation of hard fold edges. Magnetization transforms the magnetizable structure into a magnetized structure.

[0014] An advantage of the invention is that the magnetizable structure can be positioned in the magnetization space intact or as a whole. This eliminates the need to cut the magnetizable structure and assemble individual parts into the magnetized structure.

[0015] In principle, various inorganic materials (such as metals) and organic materials (such as conductive polymers, carbon, graphite, graphene, etc.) are suitable for the magnetizable material, provided they are magnetizable and can preferably be processed by printing or coating methods, e.g., as a paste or ink. Preferably, the thickness of the magnetizable material applied to the substrate plate, especially when printed, is 100 nm to 3 mm, more preferably 10 pm to 500 pm. This allows for a particularly compact and easily deformable design of the magnetizable structure. The thickness of the magnetizable material is defined here as the dimension of the applied layer(s) of magnetizable material measured orthogonally to the surface of the substrate plate.Preferably, the magnetizable material should, firstly, be suitable for processing into films or layers using various techniques, and secondly, allow for easy curing / drying / post-treatment of these films and layers by thermal treatment at moderate temperatures (below 140°C) that are compatible with elastomeric or thermoplastic substrates and components. In particular, the magnetizable material is applied to and attached to the substrate plate in a flat or structured manner. Preferably, the magnetizable material contains magnetizable microparticles and / or nanoparticles. Preferably, the microparticles have an average particle size of 100 nm to 500 pm, more preferably 5 to 25 pm or 50 to 100 pm. In particular, the magnetizable microparticles and / or nanoparticles contain nickel, iron, or magnetizable alloys.Preferably, the microparticles are contained in an amount of 30 to 90 wt.%, preferably 70 to 85 wt.%, in the magnetizable material.

[0016] In particular, the magnetizable structure has a width, a length, and / or a height or thickness. Specifically, the thickness of the structure is 50 µm to 1 mm, and / or the width is 10 mm to 50 cm, and / or the length is 10 mm to 6 m.

[0017] In particular, the substrate plate has a layer thickness of 1 pm to 500 pm, preferably 25 pm to 250 pm, and most preferably 50 pm to 150 pm. This allows for a particularly compact and easily deformable design of the substrate plate. At the same time, the weight of the magnetizable structure can be kept low. Preferably, the substrate plate has a rectangular shape. The substrate plate contains a dielectric material. In particular, the substrate plate contains a polymer as the dielectric material, especially a thermoplastic elastomer, e.g., a thermoplastic polyurethane (TPU).

[0018] In a preferred embodiment of the method according to the invention, the magnetizable structure has two opposite sides spaced apart along a width direction of the magnetizable structure, wherein the rolling occurs along a rolling axis that runs parallel to the width direction, and / or wherein the folding occurs along one or more fold edges that run parallel to the width direction. In this way, each of the side edges is superimposed such that, from a perspective perpendicular to the surface of the substrate plate, they run parallel and can thus be aligned together with a magnetic field. Preferably, the rolling occurs over at least the length of one winding layer. Preferably, the folding occurs such that the outer dimension of the magnetizable structure is at least halved in the length direction.

[0019] In a further preferred embodiment of the method according to the invention, magnetization takes place within a homogeneous magnetic field. This promotes the formation of uniformly polarized sides of the magnetized structure.

[0020] In a further preferred embodiment of the method according to the invention, magnetization is carried out by means of a magnetic field passing through the entire magnetizable structure. This promotes the formation of uniformly polarized sides of the magnetized structure.

[0021] Preferably, magnetization is carried out using a magnetizing device with a magnetizing chamber. In particular, the magnetizing device comprises a magnetizing coil with a substantially cylindrical magnetizing chamber. Specifically, the diameter of the cross-section of the magnetizing chamber is smaller than the original length of the sides of the uncoiled or unfolded magnetizable structure.

[0022] In a further preferred embodiment of the method according to the invention, the following steps are carried out before the magnetizable structure is provided:

[0023] Applying, in particular printing, a magnetizable paste or ink to the substrate plate; and

[0024] Curing, in particular by heating or exposure to light, of the paste or ink to form a magnetizable material. In a further preferred embodiment of the method according to the invention, the following step is carried out after magnetization:

[0025] Unrolling and / or unfolding the magnetized structure into a flat form.

[0026] As described above and below, the problem set out at the beginning is also solved by a method with the features of claim 7.

[0027] The inventive method for producing a multilayer composite article exhibiting sensory functionality, in particular a hose, a drive belt, a conveyor belt and / or an air spring, containing an elastomeric material and preferably a reinforcing element, comprises the following steps:

[0028] Producing a planar magnetized structure according to the aforementioned inventive method; and

[0029] Attaching the planar magnetized structure to the multilayer composite article.

[0030] The attachment of the planar magnetized structure to the multilayer composite article is achieved in particular by embedding the magnetized structure in one of the layers or between two of the layers of the multilayer composite article.

[0031] The elastomeric material of the multilayer composite article contains, in particular, an elastomer and / or a thermoplastic elastomer. The reinforcing layer may contain a metal and / or a textile.

[0032] In particular, the magnetized structure forms at least part of a detection strip in a multilayer composite article designed as a drive belt for position or cycle determination. In particular, the magnetized structure forms at least part of a crack detection sensor in a multilayer composite article designed as a conveyor belt.

[0033] It is expressly pointed out that the embodiments of the invention described above can each be combined individually or in any technically meaningful combination with each other with the subject matter of the independent claims.

[0034] Variations and embodiments of the invention, as well as further advantages and details of the invention, can be found in the following description and the drawings. The schematic figures show:

[0035] Fig. 1a A planar magnetizable structure, such as can be manufactured to form a magnetized structure according to an embodiment of the invention, in a top view;

[0036] Fig. 1b shows the magnetizable structure from Fig. 1a in a side view;

[0037] Fig. 2a shows the magnetizable structure from Fig. 1a in a rolled-up state;

[0038] Fig. 2b shows the magnetizable structure from Fig. 1b in a rolled-up state;

[0039] Fig. 2c shows the magnetizable structure from Fig. 2a positioned in a magnetization space;

[0040] Fig. 2d shows the magnetizable structure from Fig. 2b positioned in a magnetization space; Fig. 3a shows the magnetizable structure from Fig. 1a in a folded state;

[0041] Fig. 3b shows the magnetizable structure from Fig. 1b in a folded state;

[0042] Fig. 3c shows the magnetizable structure from Fig. 3a positioned in a magnetization chamber;

[0043] Fig. 3d shows the magnetizable structure from Fig. 3b positioned in a magnetization chamber;

[0044] Fig. 4 shows the magnetizable structure from Fig. 1a in a detailed side view;

[0045] Fig. 5 shows an embodiment of a magnetized structure produced using the inventive method in a view analogous to Fig. 1a;

[0046] Fig. 6 shows a flowchart of an embodiment of the inventive method for producing a magnetized structure;

[0047] Fig. 7 shows a flowchart of an embodiment of the inventive method for producing a multilayer composite article having sensory functionality.

[0048] Parts that have the same or similar effects are provided with identical reference numerals, if applicable.

[0049] Individual technical features of the embodiments described below can also be combined with previously described embodiments, as well as with the features of the independent claims and any further claims, to form objects according to the invention. Figures 1a to 4 show a magnetizable structure 1. In its original form, the magnetizable structure 1 has a width BO, a length LO, and a height HO (see Figures 1 and 4), which define a width direction B, a length direction L, and a height or thickness direction H of the magnetizable structure 1. Here, the length LO and width BO are each many times greater than the height HO. In the present case, the magnetizable structure 1 has a rectangular shape. As is particularly well illustrated in Figure 4, the magnetizable structure 1 has a flexible substrate plate 4 on which a magnetizable material 5 is arranged.The magnetizable material 5 can, for example, be printed onto the substrate plate 4 as a magnetizable paste or ink and then cured, for example by heating or exposure.

[0050] The magnetizable structure 1 has two opposite sides 2 and 3, spaced apart along its width direction B. The magnetizable structure 1 is to be magnetized such that the opposite sides 2 and 3 have opposite polarities. Fig. 5 shows such a magnetized structure 1a with two opposite sides 2a and 3a with opposite magnetic polarities. A north pole N forms along the side 2a shown above, while a south pole S forms along the side 3a shown below. In other words, the direction of the magnetic dipole of the magnetized structure 1a is to run parallel to the surface of the substrate plate 4 and perpendicular to the sides 2a and 3a.

[0051] To produce the magnetized structure 1a, the magnetizable structure 1 must be magnetized in a magnetization chamber 40 in which a preferably homogeneous magnetic field M can be generated. Homogeneous magnetic fields can advantageously be generated inside a current-carrying coil, resulting in a substantially cylindrical magnetization chamber 40.

[0052] According to the invention, the magnetizable structure 1 is rolled up and / or folded before magnetization, thereby reducing its external dimensions. This enables magnetization even in compact magnetization spaces. In particular, magnetization spaces can also be used whose cross-sections have a diameter D1 that is smaller than the length LO of the sides 2, 3 of the magnetizable structure 1.

[0053] Figures 2a to 2d show steps of a first embodiment of the method according to the invention. Here, the magnetizable structure 1 shown in Fig. 1 is rolled along a rolling axis A, which runs parallel to the width direction B (Figures 2a and 2b). This reduces the original length LO of the magnetizable structure 1 to a shortened length L1. The magnetizable structure 1 can then be positioned in the cylindrical magnetization chamber 40 and a homogeneous magnetic field M can be passed through it for magnetization.

[0054] Figures 3a to 3d show steps of a second embodiment of the method according to the invention. Here, the magnetizable structure 1 shown in Fig. 1 is folded along several fold edges F1, F2, F3, each running parallel to the width direction B, and folded compactly in a zigzag shape, forming hard fold edges. In an alternative embodiment according to the invention, the magnetizable structure 1 can be folded in a meandering shape without forming hard fold edges. This reduces the original length LO of the magnetizable structure 1 to a shortened length L1. The magnetizable structure 1 can then be positioned in the cylindrical magnetization chamber 40 and a homogeneous magnetic field M can be applied through it for magnetization.

[0055] Preferably, magnetization is carried out by means of a magnetic field M passing through the entire magnetizable structure 1.

[0056] Fig. 5 shows the magnetized structure 1a unrolled and / or unfolded into a planar structure after magnetization. Fig. 6 shows a flowchart of an embodiment of the inventive method 100 for producing a planar magnetized structure 1a with two opposing sides 2a, 3a with opposite magnetic polarity, comprising the following steps:

[0057] - Providing 110 of a magnetizable structure 1, comprising a flexible substrate plate 4 on which a magnetizable material 5 is arranged, in particular printed;

[0058] - Rolling 120 and / or folding the magnetizable structure 1; and - Magnetizing 130 the rolled or folded magnetizable structure 1.

[0059] Optionally, procedure 100 includes the following step:

[0060] - Unrolling and / or unfolding of the magnetized structure 1a into a planar form.

[0061] Fig. 7 shows a flowchart of an embodiment of the inventive method 200 for the production of a multilayer composite article having sensory functionality, in particular a hose, a drive belt, a conveyor belt and / or an air spring, containing an elastomeric material and preferably a reinforcing element, comprising the following steps:

[0062] Producing 210 a planar magnetized structure 1a according to the method 100 according to any one of claims 1 to 6; and

[0063] Attach 220 of the planar magnetized structure 1a to the multilayer composite article.

[0064] It should also be noted that "showing" does not exclude any other elements or steps and "a" or "an" does not exclude a multitude.

[0065] The scope of protection of the present invention is defined by the patent claims and is not limited by the features explained in the description or shown in the figures.

Claims

Patent claims 1. Method (100) for producing a planar magnetized structure (1a) with two opposing, differently magnetically polarized sides (2a, 3a), comprising the following steps: - Providing (110) a magnetizable structure (1) comprising a flexible substrate plate (4) on which a magnetizable material (5) is arranged, in particular printed; - Rolling (110) and / or folding the magnetizable structure (1); and - Magnetizing (120) the rolled or folded magnetizable structure (1).

2. Method (100) according to claim 1, wherein the magnetizable structure (1) has two sides (2, 3) spaced apart from each other and opposite each other along a width direction (B) of the magnetizable structure (1), wherein the rolling (110) takes place along a rolling axis (A) which runs parallel to the width direction (B), and / or wherein the folding (110) takes place along one or more fold edges (F1, F2) which run parallel to the width direction (B).

3. Method (100) according to claim 1 or 2, wherein the magnetizing (120) takes place within a homogeneous magnetic field (M) 4. Method (100) according to one of the preceding claims, wherein the magnetization (120) is carried out by means of a magnetic field (M) passing through the entire magnetizable structure (1).

5. Method (100) according to any of the preceding claims, wherein the following steps are carried out before providing (110): - Applying, in particular printing, a magnetizable paste or ink to the substrate plate (4); and - Curing, in particular by heating or exposure, of the paste or ink to form a magnetizable material (5).

6. Method (100) according to any one of the preceding claims, wherein after magnetizing (120) the following step is carried out: - Unrolling and / or unfolding of the magnetized structure (1a) into a planar form.

7. Method (200) for manufacturing a multilayer composite article having sensory functionality, in particular a hose, a drive belt, a conveyor belt and / or an air spring, comprising an elastomeric material and preferably a reinforcing element, comprising the following steps: - Manufacturing (210) a planar magnetized structure (1a) according to the method (100) according to any one of claims 1 to 6; and - attaching (220) the planar magnetized structure (1a) to the Multi-layer composite articles.

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