DE102016222642A1 - Inspection belt - Google Patents

Abstract

A test band intended to be adhered to a surface comprising at least two superimposed layers, wherein an upper layer for removing the test band from a surface along a pulling direction is provided, and wherein a lower layer has at least one separating portion which in Substantially transverse to the pulling direction.

Description

The present invention relates to a test tape, a test method, in particular a surface test method, and a use of a test band or a test method.

If on surfaces of workpieces, be it metal or plastic, liquids, such as paints, adhesives or the like, to be applied, the surface tension of the workpiece is an important parameter, the z. B. determines the wettability of the surface with the liquid in question. In the automotive industry, in particular in the body shop, for example, often raises the question of whether a certain surface is suitable for bonding. It is known to make sample coatings, cure and then check the strength. It is also known to carry out contact angle measurements. In this case, a drop of a test liquid is applied to the surface to be assessed and illuminated from the side. The contact angle is then determined manually, for example, by applying an angle measuring device tangentially to the circle segment of the liquid drop at the point of intersection with the surface and reading off the contact angle. Both approaches are time-consuming and based on a variety of steps. A slightly faster procedure consists of brushing the workpiece surface with different test inks, the surface tension of which gradually increases. In fact, this approach also turns out to be too costly in daily practice.

It is therefore an object of the present invention to provide a test band, a test method and a use of a test band or a test method, which eliminate the aforementioned disadvantages and are simple and inexpensive.

This object is achieved by a test strip according to claim 1, a test method according to claim 8 and by a use according to claim 10. Further advantages and features will become apparent from the dependent claims and the description and the accompanying figures.

According to the invention, a test strip, which is provided for adhering to a surface, at least two superimposed layers, wherein an upper layer for removing / removing the Prüfbands from a (to be tested) surface along a pulling direction is provided, and wherein a lower layer at least one Separation region which extends substantially transverse to the pulling direction. This makes possible a very effective rapid test based on the test tape, which can be used on the spot and can be pulled off without residue (by hand) in one or two steps. For this purpose, the upper layer is expediently provided for removing / removing the test band from the surface to be tested. Depending on the surface properties of the surface, the lower layer adheres to the surface or, if the adhesive is poor, together with the upper layer, which is pulled off along the direction of pull, is removed with good adhesion. This means that a bond between the lower and the upper layer is greater than an adhesive force between the lower layer and the surface to be tested. In this respect, it can be very quickly and easily detected whether a surface, for example, by previous steps, contaminated and thus for subsequent process steps such. B. for painting, coating or bonding, is suitable or not. For example, if a surface is slightly oily or contaminated, even though it has already been cleaned, it can be detected quickly and easily using the test tape. Advantageous for the functionality of the test band is the provision of the at least one separation region, which extends essentially transversely to the pulling direction. So this ensures that the lower layer is not claimed as far as peeling, but only in the normal force direction, ie substantially perpendicular to the surface (head). Preferably, a plurality of such separation areas is provided, which are designed so that the tensile force applied by the upper layer, in its removal, acts as perpendicular to the lower layer as possible.

Conveniently, the lower layer is provided on its underside with a corresponding adhesive or adhesive layer, which is designed to fasten the test strip on the surface to be tested, which may be formed for example of a metal or plastic, in particular also of a fiber composite material or stick.

Advantageously, the test band has a predetermined bond strength. In particular, between the lower layer and the upper layer, a predetermined bond strength or adhesive force acts. For example, an adhesive layer or adhesive layer is provided between the upper and the lower layer, which provides a predetermined bond strength or adhesive force. In this case, the term adhesion or adhesive force denotes that force (in N / mm) which is necessary to remove an adhesive strip (of a certain width) from a surface, in the present case thus to pull off the upper layer from the lower layer. Expediently, the bond strength or the adhesive force or adhesive force is precisely set or predetermined, since this represents a reference bond strength or reference bond, so to speak, which serves to assess the surface finish of the surface. It should be noted that between the lower layer and the upper layer no adhesive must be present. The decisive factor is the provision of a detachable connection, with a certain strength, wherein the force at which the "release" occurs is set or predetermined with advantage. According to one embodiment, between the lower and the upper layer z. B. also provided an adhesive layer in the manner of a Velcro connection.

Advantageously, the bond strength or adhesion between the lower layer and the upper layer is selected depending on a surface finish of the surface. Typical bond strength values between the top and bottom layers are in a range of about 2-7 N / mm ² according to various embodiments of the test band. Examples of suitable adhesives for forming or forming the adhesive layer or adhesive layer are materials such as epoxy resin (EP), polyurethane (PU), etc.

Conveniently, the at least one separation region is an incision, in particular, for example, in the form of a perforation or a predetermined breaking point. Conveniently, the separation area is designed such that easy or simple release of the sections formed by the separation areas of the lower layer is possible.

Conveniently, a plurality of separation areas is provided, wherein the separation areas are arranged in each case, in other words two successive separation areas, preferably at a distance of about 0.5 to 8 mm, more preferably at a distance of 0.8 to about 6 mm , In this respect, the separation areas form a lower layer, which consists of a plurality of juxtaposed strips. Expediently, the separation regions are arranged substantially parallel to one another, the distance of the separation regions or the width of the strips being substantially constant. Alternatively, however, different widths can be realized. Basically, it has been found that the desired head-pull can be realized in the best possible way by the aforementioned dimensions. If the strips are too wide, peeling may already occur, if they are too thin, the resulting adhesive force or adhesive effect is too small to enable a reliable statement with regard to a surface finish.

According to one embodiment, the lower layer is substantially transversely to the pulling direction, in other words in the cutting direction, reinforced, for example, fiber-reinforced. This feature also contributes to the best possible ensure or realize the desired head.

It should be noted that as the materials for the upper and lower layers in preferred embodiments, suitable plastic film materials are suitably used, such as: polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polypropylene (PP), polytetrafluoroethylene (PTFE ), Polystyrene (PS) or polycarbonate (PC) or combinations of the aforementioned materials. Typical thicknesses of the layers are, according to various embodiments, in a range of approximately 0.1 to 2 mm each.

According to one embodiment, a foam-like intermediate layer is arranged or provided between the lower layer and the upper layer. The provision of the foam-like intermediate layer advantageously enables the tensile forces applied by the upper layer to act on the lower layer as far as possible in the normal direction, so that the above-mentioned head-pull is optimally realized. In one embodiment, the intermediate layer is likewise formed as the adhesive layer or adhesive layer which is provided between the upper and the lower layer. Alternatively, the foam-like intermediate layer can also be provided on the top and bottom sides with an adhesive layer, whereby it does not develop an adhesive effect itself.

According to one embodiment, the adhesive layer or the adhesive layer or the aforementioned intermediate layer is also provided with separation areas, for example in the form of incisions, perforations, etc., which run essentially transversely to the pulling direction and, as already mentioned, the securing or realization of the serve desired Kopfzugs.

According to one embodiment, the lower layer also has one or more, in particular a plurality of separation areas in the form of incisions, perforations, predetermined breaking points, etc., which are formed in the pulling direction. In this respect, for example, a kind of checkered or matrix-shaped arrangement of separation areas is realized. This allows, when removing the top layer, a very accurate and accurate localization of any surface contamination. Thus, for example, after removing the upper layer, individual fields or portions of the lower layer remain adhered to the surface, while others are removed together with the upper layer.

According to one embodiment, the upper layer is strip-shaped and additionally has z. B. a tab for removing the upper layer.

According to various embodiments, the test band may be in the form of a windable band be educated. Alternatively, the test band can also be formed as a flat section, for example. Dimensionally it is not subject to any restrictions. The test tape is especially designed and provided to detect interfering contaminations / contaminations on / on surfaces to be bonded. So z. B. after the mechanical processing and cleaning of an adherend (top) surface by means of the Prüfbands be ensured that not yet, for example, silicones or other substances are present on the surface, which may adversely affect the subsequent bonding. Silicones are z. B. not solved by most cleaning agents. Advantageously, this can be detected by the test band and the resulting rapid test.

• - Aufkleben einer ersten Lage auf eine (zu prüfende) Oberfläche;
• - Entfernen bzw. Abziehen einer auf der ersten Lage befestigten oder befestigbaren zweiten Lage;
• - Auswerten, ob und wo sich die zweite Lage von der ersten Lage löst bzw. die erste Lage von der Oberfläche.

The invention is also directed to a test method, in particular a surface test method, comprising the steps:

• Adhering a first layer to a surface (to be tested);
• Removing or removing a second layer fastened or fastened on the first layer;
• - Evaluate if and where the second layer of the first layer dissolves or the first layer of the surface.

• - Bereitstellen eines erfindungsgemäßen Prüfbands.

Preferably, the method comprises the step:

• - Providing a test strip according to the invention.

In this respect, the first layer corresponds to a lower layer and the second layer corresponds to an upper layer of the test strip according to the invention.

Advantageously, it is thus possible, for example, to make a statement as to whether a surface is suitable for a matching bond or coating or coating. Such a method is inexpensive, easy to interpret and very fast in the application.

• - Entfernen bzw. Abziehen der ersten/unteren Lage von der Oberfläche.

Conveniently, the method further comprises the step:

• - Removal or removal of the first / lower layer from the surface.

Appropriately, the adhesive or adhesive force of the first / lower layer is formed to the surface or the corresponding adhesive chosen so that a residue-free removal is possible. The removal or removal of the first / lower layer is necessary after removal of the second / upper layer only at the points at which the adhesive force of the surface was or is sufficient. At the points at which the first / lower layer has already been removed together with the second / upper layer, the bond strength of the surface can be classified as possibly insufficient.

The invention is also directed to a use of a test band according to the invention or of a test method according to the invention in motor vehicle construction, in particular in body construction.

The advantages and features mentioned in connection with the test band apply analogously and correspondingly for the test method and the use, as well as vice versa and with each other.

Further advantages and features will become apparent from the following description of a test strip with reference to the accompanying figures.

• 1: ein Prüfband in einer Draufsicht;
• 2: ein Prüfband in einer Seitenansicht;
• 3: zwei Ansichten eines Prüfbands, angeordnet auf einer Oberfläche.

Show it:

• 1 : a test tape in a plan view;
• 2 : a test strip in a side view;
• 3 : two views of a test band, arranged on a surface.

1 shows in a plan view a lower layer 10 , on which a band or strip-shaped upper layer 20 is arranged. The upper layer 20 extends along a pulling direction Z , Essentially transverse to the pulling direction Z indicates the lower layer 10 a plurality of separation areas or incisions 40 on which in the 1 are shown in dashed lines. Along the train direction Z becomes the upper layer 20 to perform the surface test from the lower layer 10 deducted.

To further illustrate the construction of the test band shows 2 in a side view, a test band comprising a lower layer 10 and an upper layer 20 , being between the lower layer 10 and the upper layer 20 an intermediate layer 30 which is formed, for example, as a foam-like adhesive is arranged. To recognize further is a variety of separation areas 40 which are substantially transverse to a pulling direction Z extend. For a better or further illustration of the test procedure is now on the 3 directed.

3 shows in a side view a test band comprising a lower layer 10 and an upper layer 20 , where denoted by the reference numeral Z a pulling direction is indicated, along which the upper layer 20 from the lower layer 10 is deducted, for example by hand. The entire test tape is on a surface 1 glued, being between the surface 1 and the lower layer 10 , depending on the surface finish of the surface 1 , a certain adhesion acts. In the upper part of 3 This adhesive force is less than a bond between the top layer 20 and the lower layer 10 acts, so when pulling off the top layer 20 along the pulling direction Z the lower layer 10 from the surface 1 (with) is solved. This shows that the surface 1 For example, was contaminated or dirty, in other words, does not provide sufficient adhesive properties.

In the lower view it can be seen that when pulling off the upper layer 20 along the pulling direction Z the lower layer 10 on the surface 1 sticks. This shows that the surface 1 z. B. would provide sufficiently good adhesive properties. On the representation of separation areas was in the 3 waived. Basically, these ensure that the forces passing through the upper layer 20 on the lower layer 10 be applied, if possible in the normal force direction, ie substantially perpendicular to the surface 1 , act (though the upper layer 20 when stripping is ultimately claimed to peel).

LIST OF REFERENCE NUMBERS

1

surface

10

lower position

20

upper layer

30

interlayer

40

separating region

Z

tensile direction

Claims (10)

Test strip, which is provided for adhering to a surface (1) comprising at least two superimposed layers (10; 20), wherein an upper layer (20) for removing or withdrawing the Prüfbands from a surface (1) along a pulling direction ( Z) is provided, and wherein a lower layer (10) has at least one separating region (40), which extends substantially transversely to the pulling direction (Z). Check band after Claim 1 wherein the test band has a predetermined bond strength. Check band after Claim 2 wherein the bond strength between the lower layer (10) and the upper layer (20) is selected / adjusted depending on a surface finish of the surface (1). Test strip according to one of the preceding claims, wherein the at least one separation region (40) is an incision, in particular a perforation or a predetermined breaking point. A test tape according to any one of the preceding claims, comprising a plurality of separation regions (40) spaced about 2 to 8 mm apart. A test strip according to any one of the preceding claims, wherein the lower layer (10) is reinforced substantially transversely to the pulling direction (Z), for example fiber-reinforced. A test strip according to any one of the preceding claims, wherein between the lower layer (10) and the upper layer (20) a foam-like intermediate layer (30) is arranged. Test method, in particular surface test method, comprising the steps: - adhering a first layer (10) to a surface (1); Removing or removing a second layer (20) fastened or fastened on the first layer (20); - Evaluate whether and where the second layer (20) of the first layer dissolves or the first layer (10) of the surface (1). Test method according to Claim 8 comprising the step of: removing the first layer (10) from the surface (1). Using a test band according to one of Claims 1 - 7 or a test method according to one of Claims 8 - 9 in motor vehicle construction.

Images