WO2013167294A1

WO2013167294A1 - Method for producing an abrasive article and abrasive article

Info

Publication number: WO2013167294A1
Application number: PCT/EP2013/054824
Authority: WO
Inventors: Josef Breitenmoser; Adrian Schoch; Stephan Fritsch
Original assignee: Robert Bosch Gmbh
Priority date: 2012-05-11
Filing date: 2013-03-11
Publication date: 2013-11-14
Also published as: DE102012207908A1

Abstract

A description is given of a method for producing an abrasive article (1), which comprises the following steps: a) producing or providing an intermediate product (2), comprising a base (3) with a first main surface (4) and a second main surface (5) opposite from the first main surface (4); an adhesive layer (7) of a pressure-sensitive adhesive, which has been applied to the second main surface (5) of the base (3); a self-supporting protective layer (8) with a first main surface (9), which is detachably held by the adhesive layer (7), and also a second main surface (10) opposite from the first main surface (9); b) creating at least one material weakening (11) in the second main surface (10) of the protective layer (8), in particular with the aid of a first electromagnetic radiation, preferably with the aid of a first laser radiation (13). Also disclosed is an abrasive article (1) produced by this method.

Description

Method for producing an abrasive article and abrasive article

The present invention relates to a method for producing an abrasive article and an abrasive article.

Many abrasive articles, particularly coated abrasive article (English: "coated abrasive") contain connecting means with which it can be releasably secured to a bracket example, can be ^¬ consolidates sandpaper to a sanding block or grinding wheels rotatable on a.

Sanding plate. On the one hand, textile layers which contain loops which can be brought into engagement with corresponding hooks of the holder are used as connecting means. On the other hand, adhesive layers of a pressure-sensitive adhesive serve as a connecting means. The adhesive layer can be connected to a suitably formed surface of the holder and then released therefrom again, for example when the abrasive article is consumed.

In order that the adhesive layer does not lose unkontrol ^¬ prior to application to adhere to not intended for this purpose objects or the adhesive layer polluted for instance by dust, it becomes the packaging typically with a self-supporting protective layer covered (English: "release liner"). This protective layer, the user can then immediately is freige ^¬ sets removed prior to use of the abrasive article, so that a clean adhesive layer.

In order to make it easier for the user to remove the protective layer, it is known that an additional sticker (so-called "pull tab") is applied to the protective layer such that it protrudes slightly beyond the edge of the actual abrasive ^article and the protective layer is simply peeled off can. Wei ^¬ thermore, attention must known a variant in which a pull tab di- In this method, the shape of the abrasive article and the Abziehlasche is punched on the side of Schleifmit ^{¬ means} , and between the abrasive article and the Abziehlasche only the pad of the abrasive article is cut through, but not also the protective layer.

However, these production methods are very complicated and therefore costly. In addition, the aforementioned protruding stickers and pull tabs involve the risk that they are easily accidentally seized and thus the protective layer is removed early and unintentionally. He also ^¬ severe the excess labels and pull tabs packaging the abrasive article. Furthermore, stickers require additional logistics and additional waste.

It is therefore an object of the present invention to overcome the disadvantages known from the prior art. In particular, therefore, a method for producing an abrasive article is to be provided which does not have the disadvantages known from the prior art. For example, sol ^¬ len abrasive article can be prepared with the method in a simpler and less expensive manner, the protective layer is readily controlled and removable.

This object is achieved, on the one hand, by a method for producing an abrasive article which comprises the following steps: a) preparation or provision of an intermediate, the intermediate product containing:

a pad having a first major surface and a second major surface opposite the first major surface; - an adhesive layer of a pressure sensitive adhesive which is aufgetra ^¬ gene on the second major surface of the backing;

- A self-supporting protective layer with a first

A major surface releasably supported by the adhesive layer and a second major surface opposite the first major surface; b) generating at least one material weakening in the second main surface of the protective layer, in particular by means of a first electromagnetic radiation.

Under a material weakening a portion of the protective layer is understood here and below, in which the latter has in a direction perpendicular to its main surface, a second coagulating ^¬ Gere thickness than in the remaining regions. Zweckmässi ^¬ gerweise the material weakening should be designed such that the protective layer in the region of the material weakening by deforming, in particular bending and / or buckling, of the abrasive article is at least partially detachable from the adhesive layer. In particular, by deforming, two or more portions of the protective layer connected via a material weakening can be separated from one another. The user can then easily grasp and remove the protective layer on the edges resulting from loosening or severing. In addition, by this method can be dispensed with additional label or supernatant from ^¬ target ashes.

In one conceivable, inventive variant, the material weakening can it be enough ^¬ using a mechanical stamping process. In this case, the protective layer can be completely or only partially severed, but the pad is not or only partially severed. The preferred use of electromagnetic radiation material weakening can be generated in a particularly simple, precise and constant manner. This applies in particular when the first electromagnetic radiation is a first laser radiation. Compared to mechanical stamping process using electromagnetic radiation has a number of advantages: There will be no wear of Stanzmes ^¬ fibers, it is not a tool storage for various Konfekti ^¬ onsformen necessary, and it is only a very small set-up time when changing the shape of the material weakening necessary. Another disadvantage when punching with punching blades is that they have to be polluted by the adhesive and have to be periodically cleaned because this makes it easier to remove the punched parts from the punching knives and, under certain circumstances, favors the risk of foreign-grain transfer.

The backing may consist of a single layer, for example of a paper, of a film, which may in particular be thermoplastic, a textile material or a foam. Alternatively, the pad may also contain a plurality of interconnected sub-layers, such as a first sub-layer of a foam and a second part ^¬ layer of a textile material. The first major surface of the backing of the prepared in step a) or bereitge ^¬ easily intermediate may carry an abrasive. Alter ^¬ natively, it is also conceivable that the abrasive is applied only after the production of the weakening of material in step b) on the first main surface of the pad.

With particular advantage, at least one material weakening ^¬ penetrates the protective layer in a direction transverse to its second main surface direction completely. In this way, the user can remove the protective layer particularly easy because the protective layer does not even have to be cut. It However, it is also conceivable and within the scope of the invention that the material weakening only partially penetrates the protective layer in a direction transverse to its second main surface. The protective layer then has a certain thickness in the area of the material ^weakening . By choosing the thickness of the protective layer in this area, the force that the user has to apply for loosening or severing the protective layer can be set. The adhesive force and the amount of the pressure-sensitive adhesive also have an influence on the detachment behavior.

Advantageously, the material weakening of the protective layer is produced in such a way that a weakening of the material is not produced in the backing as a result. In this way it can be prevented that the pad itself is weakened and the ^abrasive article thereby becomes unstable.

In step a) can expediently also the contour of the interim ^¬'s product by means of a second electromagnetic

Radiation generated. In this case, the term "contour" is understood to mean the outline of the abrasive article, in particular, the term "contour" encompasses the outer contour of the abrasive article - that is, for example, the circular outer contour of a Schleifschei ^¬ be. In addition, the term "contour" also includes any openings (for example for dust extraction) which penetrate all layers of the intermediate product In this embodiment, the material weakening and the contour are generated by electromagnetic radiation and therefore in substantially the same way the production can be significantly reduced.

This advantage is particularly pronounced when the contour of the intermediate product is generated by means of a second laser radiation. The generation of the contour of an abrasive article by means of laser radiation per se is known to the person skilled in the art. By the inventive method can, however, with the same means a material weakening be generated in the protective layer. It is extremely favorable if the first laser radiation and the second laser radiation are emitted by the same laser. In this way, therefore, the material weakening of the protective layer and the contour of the intermediate product with the same laser can be ^¬ he testifies, which is structurally and procedurally particularly favorable.

Thus the first laser radiation only causes a weakening of the material in the protective layer, but not in the sub ^¬ location, the second laser radiation with which the contour is produced, can have a higher intensity at which the material weakening is produced as the first Laserstrah ^¬ lung, , In addition, the adhesive layer may serve to compensate for the energy of the first laser ^¬ radiation, so that this laser radiation does not penetrate into the backing. By means of routine tests, the ^person skilled in the art can ascertain which intensities are required in order to achieve the desired degree of material weakening, in particular the desired thickness of the protective layer in the region of the material ^weakening .

Alternatively, it is also conceivable that the point of action of the first laser radiation is moved at a higher speed over the protective layer than the point of action of the two ^¬ th laser radiation. It is also conceivable that the first La ^¬ serstrahlung a first wavelength and the second Laserstrah ^¬ lung has one different second wavelength, said laser radiation of the second wavelength greater

Cutting action generated as the laser radiation of the first wavelength. The skilled artisan can determine through routine experimentation suitable Ge ^¬ speeds and / or wavelengths.

At least one material weakening may be formed linearly within the second main surface of the protective layer. Such a linear training allows a special simple solution or breakthrough of the protective layer. In particular, the material weakening can have straight sections and / or curved sections. Advantageously, the material weakening begins at a first edge point of the abrasive article and ends at a different from the first edge point second edge point of the abrasive article. Further, the material ^¬ weakening can at least partially extend in the central region of the protective layer, in particular through its center. However, it is also conceivable that the material weakening is arranged only in the outer region of the protective layer. Furthermore, in some embodiments, only a single contiguous weakening of material may be created. However, it is also conceivable that several non-interconnected Ma ^¬ terialschwächungen be generated.

The protective layer may be made of any material which is self-supporting from ^¬ reaching and enables a releasable connection with the pressure sensitive adhesive. In particular, the material of the ^¬ art should be selected such that the portions formed by cutting through the protective layer can be dissolved in each case in one piece from the pressure-sensitive adhesive ^¬. In addition, the material of the protective layer should be selected such that can be generated with the aid of electromag netic ^¬ radiation, in particular laser radiation, a material weakening. In particular, the protective layer may contain or be made of a material known ^per se, which should be flexible, web-like and non-adhesive in particular, such as a film

and / or a paper. Also conceivable are siliconized (in particular waxed, oiled and / or stearated) materials or poorly adhering plastics such as polypropylene or polyethylene.

Another aspect of the invention relates to an abrasive article which is obtainable, in particular, by a process as described above. The abrasive article contains - a backing having a first major surface and ei ^¬ ner the first principal surface opposite second major surface;

an adhesive layer of a pressure sensitive adhesive applied to the second major surface of the backing;

- a self-supporting protective layer having a first major surface ^¬ which is detachably supported ^¬ th from the adhesive layer, and one of the first main surface opposite second major surface.

According to the invention includes the second major surface of the protective layer ^¬ least one material weakness. This allows the on ^¬ pancake particularly simple replacement of the protective layer. The material weakening may have been generated, for example, by means of a first electromagnetic radiation, in particular a first laser radiation, as described above. The fact that the material weakening was generated with the aid of laser radiation can be recognized by the person skilled in the art in the structure of the protective layer, in particular its second main surface, and / or the second main surface of the substrate in the area of material weakening. For example, it can be stated that the material of the protective layer and / or the substrate has been melted in the region of the material weakening. Thus, for example, with a base made of paper, certain burn marks are produced, and with a base of a thermoplastic foil ent ^¬ stands a melted area.

The abrasive article may also have one or more of the other properties discussed above. For example, at least one material weakening can completely penetrate the protective layer in a direction transverse to its second main surface. Furthermore, it is advantageous if the pad has no material weakening. In addition, preferably, the abrasive article not be above ^¬ signed additional label or pull tabs. In particular, the support and the protective layer in the materiality ^¬ union may be congruent. On the one hand, this material can be saved. In addition, the handling of the abrasive article can be facilitated.

In the following the invention will be explained with reference to several Ausführungsbei ^¬ games and drawings. Show it

FIG. 1 shows a sectional view of an intermediate product from which an abrasive article according to the invention can be produced;

FIG. 2 shows a schematic representation of a method according to the invention for producing an abrasive article from the intermediate product according to FIG. 1;

Figure 3: a sectional view of an inventive

Abrasive article, which was produced by a method according to the invention according to FIG. 2;

FIGS. 4a to 4e are top views of four inventive ^examples of abrasive articles in the direction of the second main surfaces of their respective protective layers.

In the sectional view according to FIG. 1, an intermediate product 2 is shown, from which an inventive abrasive article 1 shown in FIG. 3 can be produced. The intermediate product 2 ^¬ a base 3 having a first major surface 4 and upper ^¬ one of the first major surface 4 gegenüberlie ^¬ constricting second major surface includes 5. The pad 3 may be made for example from a paper or a textile material. The first Main surface 4 carries an abrasive 6 which may contain at least one binder and abrasive grains. For example, the abrasive may also include a base binder that fixes the abrasive grains to the first major surface 4, and at least one size coat binder that covers both the base binder and the abrasive grains.

On the second main surface 5 of the base 3 an adhesive ^¬ material layer 7 is applied from a pressure sensitive adhesive. For this purpose, any known per se pressure-sensitive adhesive can be used, unless it is destroyed by the registered electromagnetic radiation. For example, a hot melt adhesive, a dispersion (in particular an emulsion) or a resin can be used as pressure-sensitive adhesive. In particular, acrylic-based products such as Synthomer 10A33, available from Synthomer GmbH, Frankfurt / Main, Germany, are suitable.

From the adhesive layer 7, a first main surface 9 ei ^¬ ner self-supporting protective layer 8 is releasably held. The protective layer 8 may be, for example, a film han ^¬ spindles, which may have approximately a thickness of 20 to 150 ym, for example 70 ym. Opposite the first main surface 9, the protective layer 8 has a second main surface 10.

An intermediate product 2 shown in FIG. 1 can be prepared by a process known per se, which can form sub-step a) of the process according to the invention. For example, first, a grinding means 6, which consists of a binder and abrasive grain, are applied to the first Hauptoberflä ^¬ surface 4 of the base. 3 On the second main surface 5, the adhesive layer 7 can be aufgetra ^¬ gen afterwards. Then, the protective layer 8 can be fixed on the adhesive layer 7. Subsequently, the contour of the intermediate product 2 can be generated. For this purpose, a second laser radiation can be used, with both the outer contour as well as any of the intermediate 2 completely durchdrin ^¬ ing openings can be generated. As is known to the person skilled in the art, individual of said method steps can also be carried out in a different order. For example, might also be first the adhesive layer 7 and protective layer 8 ^¬ be applied to the substrate 3 and only after the abrasive. 6

FIG. 2 shows diagrammatically how an inventive abrasive article 1 can be produced by means of a process according to the invention from the intermediate product 2 according to FIG. For this purpose, a material weakening 11 is generated in the second main surface 10 of the protective layer 8. This is done with the aid of a first laser radiation 13, which is emitted by a laser 12. The first laser radiation 13 can be selected, for example, such that the material weakening 11 only partially penetrates the protective layer 8. The shape of the illustrated material ^¬ weakening 11 (see also Figures 4a to 4e) can be produced by movement of the laser beam 13 relative to the intermediate product. 2 In particular, this can be done using an optical system which includes one or more movable, depending ^¬ but not shown here mirrors that direct the Laserstrah ^¬ lung 13 from the laser 12 to the second major surface of the tenth

FIG. 3 shows a sectional view of an inventive device

Abrasive article 1, which was produced by the method shown in Figure 2. The second major surface 10 of the protective layer 8 ^¬ contains a weakening of the material 11. This means ^¬ al so that the protective layer 8 has in this region a smaller thickness perpendicular to its second main surface 10th By deforming the abrasive article 1, the user can sever the protective layer 8 in the region of the material weakening 11 and easily detach the sections resulting therefrom from the adhesive layer 7. 4a to 4e illustrate in plan views of the second main surfaces 10 different forms of possible weakening of the material 11. According to the material weakening 4a figure (which coincides with the character ^¬ plane) by a single straight line 11 is formed in the plane of the second major surface 10, which the center of the circular abrasive article 1 ent ^¬ holds and extends from a first edge point 15 of the abrasive article 1 to a second edge point 15 '. FIG. 4 b likewise shows a rectilinear weakening of the material 11, which, however, does not include the center of the abrasive article 1. The 4c represents ^¬ asked in FIG embodiment includes two curve-shaped, non-contiguous with each other material weakenings 11. In Figure 4d, an abrasive article 1 is illustrated, which includes two Einan ^¬ the intersecting each linear material weakenings. 11 In Figure 4e, an abrasive article 1 is shown, which still contains, in addition to a linear material weakening 11 openings 14, which fully penetrate the abrasive article 1 by ^¬, and can be produced for example by means of a second laser radiation. Of course, not only circular outer contours of the abrasive article are possible, but also, for example, rectangular, in particular square.

By deformation of the abrasive article 1, the portions 16 of the protective layer 8 joined by the weakenings 11 can be separated from the adhesive layer 7, whereby the user can easily remove them.

Claims

claims

1. A method for making an abrasive article (1), umfas ^¬ send the steps of: a) preparing or providing an intermediate product (2) containing

- A pad (3) having a first main surface (4) and one of the first main surface (4) opposite gen ^¬ second main surface (5);

- An adhesive layer (7) made of a pressure sensitive adhesive, which on the second main surface (5) of the Un ^¬ terlage (3) is applied;

- A self-supporting protective layer (8) having a first main surface (9), which is detachably held by the adhesive layer (7), and one of the first main surface (9) opposite the second main surface (10); b) generating at least one material weakening (11) in the second main surface (10) of the protective layer (8), in particular by means of a first electromagnetic radiation, preferably by means of a first laser radiation (13).

2. Method according to claim 1,

characterized in that

at least one material weakening (11) completely penetrates the protective layer (8) in a direction that is trans ^¬ verse to its second main surface (10).

3. Method according to one of the preceding claims,

characterized in that

the material weakening (11) of the protective layer (8) in such a way is generated that thereby Ma ^¬ terialschwächung is generated in the pad (3).

4. Method according to one of the preceding claims,

characterized in that

in step a), the contour of the intermediate product (2) is generated with the ^{aid of} a second electromagnetic radiation.

5. Process according to claim 4,

characterized in that

the contour of the intermediate (2) is produced by using a two ^¬ th laser radiation, which in particular has a lower intensity than the first laser beam (13).

6. Process according to claim 5,

characterized in that

the first laser radiation (13) and the second laser radiation are emitted by the same laser (12).

7. Method according to one of the preceding claims,

characterized in that

at least one material weakening (11) within the two ^¬ th main surface (10) of the protective layer (8) is formed linear, in particular rectilinear sections and / or curved sections.

8. Method according to one of the preceding claims,

characterized in that

the protective layer (8) contains a foil, in particular from Polypro pylene ^¬ and / or polyethylene and / or a paper or consists thereof.

9. Method according to one of the preceding claims,

characterized in that the protective layer (8) contains a siliconized, in particular ge ^¬ wachstes, oiled, and / or steariertes, material or consists thereof.

10. abrasive article (1), in particular obtainable by a Ver ^¬ drive according to one of the preceding claims, containing

- A pad (3) with a first main surface

(4) and one of the first major surface (4) ge ^¬ genüberliegenden second major surface (5);

an adhesive layer (7) made of a pressure-sensitive adhesive,

which on the second main surface (5) of the sub ^¬ layer (3) is applied;

- A self-supporting protective layer (8) having a first main surface (9) which is detachably held by the adhesive ^¬ layer (7), and one of the first main surface (9) opposite the second main surface (10); wherein the second main surface (10) of the protective layer (8) contains at least one material weakening (11).

11. abrasive article (1) according to claim 10,

characterized in that

12. abrasive article (1) according to any one of claims 10 and 11, characterized in that

the pad (3) has no material weakening.

13. abrasive article (1) according to any one of claims 10 to 12, characterized in that

at least one material weakening (11) within the two ten main surface (10) of the protective layer (8) is formed linear, in particular rectilinear sections and / or curved sections.

14. abrasive article (1) according to any one of claims 10 to 13, characterized in that

the protective layer (8) holding a film and / or paper ent ^¬ or consists thereof.

15. An abrasive article according to any one of claims 10 to 14,

characterized in that

the protective layer contains a siliconized, in particular ge ^¬ wachstes, oiled, and / or steariertes, material or consists thereof.