The present invention relates to a method for the production of a diagnostic test device for the skin, more particularly the test plaster, provided with compartments, in accordance with the preamble of Claim 1, as disclosed in European Patent 0 ^0577.

The said test plasters are used to test the allergic reaction of the skin of a test person towards various test substances and test liquids, which to this end are introduced into the compartments in the test plaster, after which the test plaster is applied to the skin.

A test plaster of this type in accordance with EP 05^0577 generally comprises at least one compartment for taking up a diagnostic medium, an adhesive strip on which the compartment is accommodated as well as a removable protective strip attached to the adhesive strip on the same side as the compartment(s) , the protective strip being provided with an opening at the location of each compartment, wherein one or more rows of compartments is/are accommodated on the adhesive strip and the protective strip has a corresponding number of rows of openings. With this arrangement the compartments are usually, and preferably, provided with a base and a raised edge surrounding the base, the shape of the openings corresponding to the periphery of the edge.

Furthermore, the compartments of the test plaster are in practice usually provided with an absorbent material for taking up liquid, usually filter paper.

To date test plasters of this type have been produced by producing the compartment(s) individually by injection moulding and then mounting said compartment(s) in the corresponding opening(s) in a separate machine operation. So-called mats with a multiplicity of branches, each with, for example, ten compartments, are formed in an injection mould. Said mats are removed from the mould, after moulding, by means of ejector pins, after which the branches bearing the compartments are broken from the central trunk and then stored. For storage, the branches are piled in a tube to form a stack. In a further production step the branches bearing the compartments are removed from the tube one by one and laid in a slide, after which the branches are removed in such a way that the compartments remain behind in the slide. The slide is then further transported and positioned under a punching unit such

that a cutting tool is positioned above each compartment. A sheet of filter paper is laid beneath the punches, after which the punches cut squares from the filter paper, after which the punches continue to push these squares until the latter rest on the base of the compartments. The slide is then further transported to a handling device provided with suction elements or suction cups. With the aid of the suction elements or suction cups, each compartment is removed from the slide and placed on an adhesive strip.

However, this method according to the prior art has a number of serious disadvantages: an accurate, and consequently expensive, mould, is required for injection moulding of the compartments; storage of the branches bearing the compartments involves a delay, and necessitates additional storage means; applying the pieces of filter paper requires an additional step, which is labour-intensive; the cutting tools in the punching installation have cutting faces which extend transversely to the cutting direction, which results in high punching forces and heavy wear. Said heavy wear has an adverse effect on the dimensional accuracy, as a result of which the punched-out squares of filter paper are not able reliably to remain held tightly in the compartments; the compartments on a tree are not all exactly identical, which means that the cutting tools in the punching installation would each individually have to be adjusted to these differences in order to obtain squares of filter paper which are held tightly in the compartments. In practice, this adjustment of the cutting tools to the moulds is not readily possible, at least not at reasonable cost.

The separate fitting of the filter paper in the compartments can, as a consequence of, inter alia, dimensional inaccuracies, lead to inadequate adhesion between the filter paper and the compartments, with the result that the filter paper is held inadequately in place and/or in the compartments.

In order to improve this adhesion a further machining step may be required, whilst the use of adhesives can influence the test.

A further disadvantage of compartments produced by injection moulding is the consequence of the fact that very smooth and accurate surfaces of the compartments are required for good separation from the injection mould.

However, a very smooth surface of the compartments, in particular of the underside of the compartments, results in poorer adhesion of the

compartments to the adhesive strip.

As can be seen from the above, the production of the test plasters in accordance with European Patent 0 ^0577. which is known to date, is an expensive and labour-intensive process which comprises various individual production steps and as such is difficult to carry out as a fully continuous process and/or by machine. A particular problem in this context is that the compartments have to be provided with a base and a raised edge, which in practice cannot easily be combined, continuously and in conjunction, with mounting of the compartments on the adhesive strip in the openings. Up to now, therefore, a separate injection moulding step was required for shaping the compartments, the base and the raised edge thereof.

The aim of the invention is, inter alia, to overcome these disadvantages by providing a method with which test plasters of the type described in said European Patent can be produced in an efficient and simple manner, preferably continuously and/or by machine.

More particularly, the aim of the invention is to provide a method for the production of a diagnostic test device for the skin, with which method shaping of the compartments, the base and raised edge thereof, as well as mounting of the compartments thus formed on the adhesive strip in the openings intended for said compartments can be carried out continuously and in conjunction, preferably in a single machine operation.

This aim is achieved with a method as described above which has the characterising features of Claim 1.

The invention also relates to the test plasters obtained in accordance with the method.

With the method according to the present invention the test plasters are produced by carrying out the various steps of the production process, as described above, continuously and in conjunction. The wording continuously and in conjunction is used to denote that shaping of the compartments, production of the base and raised edge and mounting of the compartments on adhesive strip are carried out not in individual production operations but in production steps which are achievable in one installation or in one production operation.

In this context the method according to the invention is preferably carried out in a single machine operation. To this end it is possible to use several production installations operating in conjunction or to use one installation specifically manufactured for this purpose, and an installation of this type constitutes a further aspect of the present invention.

The strip of plastic material, the strip of plastic film, the strip of filter paper, the strip of laminate containing filter paper or the strip of filter paper provided with a liquid-impermeable or water-repellent coating is preferably a continuous strip. The raised edge is most preferentially impermeable, so that after the test plaster has been applied to the skin said plaster does not produce any leakage of the aqueous or alcoholic test solutions. The term impermeable, as used in the present application, with regard to the raised edge and the coating applied to the filter paper, is used to denote that the raised edge or, respectively, the coating is not permeable to or does not absorb, transport or release the test substance, in general a water or alcohol-based solution or a vaseline jelly-based preparation.

In the case of the method according to the present application, the filter paper loses its permeable characteristics as a result of pressing. This is a very important aspect of the present invention.

The at least one compartment is preferably provided with a base and raised edge by means of pressing, optionally in combination with heating to a temperature in order to facilitate the shaping of the compartment, the base and the raised edge, for example a temperature above the softening point of the plastic used. According to a particular embodiment, the punching and/or cutting out of one or more compartments from the continuous strip is carried out using a pressing tool and/or blanking punch which is provided with a shape such that the desired periphery of the compartments is obtained on cutting out or punching, and which can also be provided with a shape such that the punch can likewise be used for pressing the compartments, with the formation of the base and raised edge.

However, it must be understood that although shaping of the base and the raised edge can be carried out simultaneously with or after the cutting- out or punching of the one or more compartments from the continuous strip, it can also be highly advantageous if a continuous strip of plastic material, filter paper, laminate or coated filter paper is first provided with a relief pattern corresponding to the base and the raised edge, after which the compartments are then cut out or punched from the strip in such a way that the relief pattern forms the base and the raised edge of the separated compartments.

The invention also relates to a method for the production of compartments for a diagnostic test plaster, as well as compartments of this type, comprising the following steps:

shaping one or more compartments by means of pressing and cutting or punching the one or more compartments from a strip of material.

Compartments of this type produced from a strip of material by pressing and cutting have the great advantage that the surface thereof can be rough. This is because, in particular, a rough underside of the compartments makes good adhesion to the adhesive strip possible. In this context rough must be understood to mean a less smooth surface than would be obtained by injection moulding. Furthermore, compartments of this type have the great advantage that the filter paper, often required for the tests, cannot become detached from the compartments since the filter paper was already part of the strip. Further advantageous embodiments according to the invention can be seen from the subsidiary claims.

The present invention will now be explained in more detail below with reference to a drawing, solely by way of example. In the drawing:

Fig. 1 shows a perspective view, with an exposed section of a compartment according to the invention;

Fig. 2 shows a diagrammatic cross-section in which shaping of a compartment according to the invention is shown; Fig. 3 shows a diagrammatic cross-sectional view which shows a further step in shaping a test plaster;

Fig. shows a diagrammatic perspective view of part of an installation for shaping diagnostic test plasters; and

Fig. shows a diagrammatic perspective view of another installation for shaping diagnostic test plasters; and

Fig. 6 shows a diagrammatic perspective view of a diagnostic test plaster.

Fig. 1 shows a compartment 13 according to the invention for a diagnostic test device. Said compartment 13 comprises a base 15 and a raised edge 16 abutting said base 15 on all sides. Said compartment 13 has been produced in accordance with the invention by pressing and punching from a band of material. Said band of material can be made of a plastic, such as polypropene, from filter paper, etc. Said material can also have been produced from a laminate of, for example, one or more of the abovementioned materials.

In the main filter paper is mentioned below as the material for shaping the compartments 13. without the invention being restricted to said material, since this material has very advantageous properties for use in

diagnostic test plasters. In order to insulate the filter paper from the adhesive strip, when the compartment 13 has been applied to an adhesive strip, it is advantageous according to the invention if the band of filter paper is provided on the underside 20, that is to say the underside of the compartment 13 to be shaped, is provided with a film or coating, for example of polypropene. Said film is not shown individually in Figs. 1, 2 and 3. but in practice will preferably be present as a very thin layer.

Fig. 2 shows a band of filter paper 21 which extends over a die 22 provided with openings, which die is provided with cutting edges 23 around the openings. A pressing tool/blanking punch 2k and a pressure pad 25 are also shown. The shape of the top of the compartment 13 to be produced has been made in the bottom of the pressing tool/blanking punch 24. Thus, there is a recess 26 for the purposes of the thick base 15. which recess is surrounded by a rib 27. which, in turn, is surrounded by a cavity 28 for receiving the upper side of the raised edge 16. The peripheral rib 27 provides the compartment 13 with a channel 29 which runs all round the base

15-

The thick base 15 is not or is only slightly compressed during pressing and consequently has approximately the same thickness as the strip of filter paper 21. As a result of said non-compression or only slight compression, the absorbent properties of the thick base section remain virtually unchanged. If the all-round rib 27 is sufficiently wide, the channel 29 will also be sufficiently wide, such that said channel forms a liquid lock and renders transport of the diagnostic test material applied to the base 15 to the surrounding raised edge 16 more difficult. As a result of the local compression of material at the location of region 30. said transport is rendered even more difficult when filter paper is used as the material for the band 21. A channel width of 0.05 to 0.4 mm. preferably of 0.1 to 0.25 mm, is found to provide a good water lock in practice. A 0.5 to 1.25 mm, preferably 0.75 mm to 1 mm, for example 0.85 mm, thick base of filter paper has very good properties for the intended test purposes.

The mould block 25 is provided with so-called blind holes with a raised edge 31 °n the base to shape the raised edge 16 of the compartment 13. which raised edge is hollow viewed from the underside. The way in which the compartments 13 are shaped from a band of material 21 will be clear from Fig. 2. The band of material 21 is placed between, on one side, the pressing tool/blanking punch 24 and, on the other side, the die 22 in such a way that said strip completely covers the die openings in

the die 22. The pressing tool/blanking punch is then moved downward relative to the die 22 and the mould block 25- During this operation a piece, which in the present example is a square piece, will be cut out from the band of material as a result of the interaction of the cutting edges 32 of the pressing tool/blanking punch 24 and the cutting edges 23 of the die 22. Said cut-out piece of material is pushed by the pressing tool/blanking punch 24 into the mould cavity 33 in the mould block 25, the piece from the band of material being pressed into the compartment 13 shown in Fig. 1. During this operation the base section 15 will not be compressed or will barely be compressed, so that the absorption properties of the filter paper do not change, whilst that section of the cut-out piece of material which has to form the region 30 and the raised edge 16 is compressed to greater density. Said greater density of the filter paper reduces the absorbency and transport capacity of the filter paper. As soon as a compartment 13 has been shaped, the shaped compartment 13 can, as is shown diagrammatically in Fig. 3. be removed from the mould cavity 33 in the mould block 25 by means of a suction cup or suction device 40.

Fig. 4 shows, diagrammatically, a unit for shaping, in accordance with the invention, compartments for a diagnostic test plaster. Said unit consists of a die 22 provided with a multiplicity of die openings 41, and a mould block 25 which is in the form of a slide and is provided with a multiplicity of mould cavities 33. corresponding to the number of die openings 4l, and a multiplicity of suction cup devices 40, likewise in a corresponding number.

A band 21 of, preferably, filter paper is fed over the die 22 and the slide 25 is positioned with its mould cavities 33 below the die openings 41 of the die 22. The punches 24 are moved downward, during which operation they cut pieces of material from the band 21 and then press said pieces to form compartments 13. as has been described. The punches 24 are then raised back out of the mould cavities 33 and die openings 4l, after which the slide 25 is removed from beneath the die 22 and positioned with its mould cavities 33 below the suction cup devices 40. The suction cup devices 40 then remove the shaped compartments from the mould cavities 33, after which said compartments can be placed immediately on the adhesive strip of a test plaster.

Instead of the method described above, in which the cutting and successive pressing take place virtually simultaneously, it is also possible

to use a method with which first pressing and then cutting takes place. Individual pressing and cutting tools are then used, which preferably are able to move up and down simultaneously. An installation for a method of this type will advantageously have the appearance shown diagrammatically in Fig. 5-

The pressing tools 51 are arranged upstream of the cutting tools 52, which reciprocate according to the arrow R. During pressing, the pressing tools are pressed against the band of filter paper from below and interact with counter-moulds which are positioned above the band of filter paper 53 and are not shown. After pressing, the counter-moulds are lifted slightly so that the band of filter paper provided with relief, in the form of "pre¬ formed" compartments, can be transported further in the direction of arrow T. Further transport takes place in such a way that a section of the band of filter paper which is provided with relief, that is to say a pre-formed compartment, comes to rest over each die opening 55 of the die 56 located downstream. By moving down the cutting tools 52, which can be provided with oblique cutting faces, the "pre-formed compartments" 54 are cut from the band of filter paper.

The compartments which have been cut out can, if appropriate, be collected in a slide, as is shown in Fig. 4.

However, according to the invention it is particularly advantageous if a length of adhesive strip 58 is fed, for example from a roll, beneath the die, as is indicated by arrow S, so that the cut-out compartments can be positioned and, if necessary, pressed down on the adhesive strip immediately by means of the cutting tools 52. With this method, the length of adhesive strip 58 can already have been provided with a protective strip 60 provided with a number of rows of openings 59- The transport step with suction cups and the like is then superfluous.

After arranging the compartments 61 on the length of adhesive strip 58, said length can be subdivided into diagnostic test devices, as is shown in Fig. 6.

The essential steps for the method using the installation according to Fig. are as follows: feeding a band of plastic material, filter paper, laminate containing filter paper or filter paper provided with an impermeable coating to a press; pre-forming the compartments using the press; further transporting that section of the band which is provided with

pre-formed compartments to a cutting or punching installation; cutting out or punching out the pre-formed compartments from the band using the cutting or punching installation.

Preferably, with this method, the cut-out or punched-out compartments are placed on the adhesive strip by the cutting or punching installation immediately after cutting out or punching out. The cutting or punching installation and press preferably operate simultaneously, in order to increase the production speed.

In principle, the test plasters formed in this way can be of any arbitrary shape, for example the shape shown in Fig. 6.

Fig. 6 shows a diagnostic test plaster known per se from EP 05^0577- Said test plaster consists of a compartment 3 for taking up a diagnostic agent, an adhesive strip 1, on which the compartment 3 is accommodated, as well as a removable protective strip 4 attached to the same side of the adhesive strip 1 as the compartment(s) 3. the protective strip 4 being provided with an opening 7 at the location of each compartment, one or more rows of compartments 3 being accommodated on the adhesive strip 1 and the protective strip 4 having a corresponding number of rows of openings 7-

With this arrangement the compartments 3 are usually, and preferably, provided with a base 5 and a raised edge 6 surrounding the base, the shape of the openings 7 corresponding to the periphery of the edge 6.

Furthermore, in practice the compartments 3 of the test plaster are usually provided with an absorbent material for taking up liquid, usually filter paper. In contrast to what is shown in European publication 0540577. however, the compartment is produced as in accordance with the invention. As far as the test plaster in Fig. 5 is concerned, reference is also made to European Patent 05 0577. which must be considered to be incorporated herein by reference. As stated above, the present invention has three main embodiments, depending on the material from which the compartments are formed. These embodiments will now be discussed individually: A Compartments formed from plastic

According to this embodiment, the compartments are formed by cutting out or punching from a continuous strip of plastic material. Although any material which is suitable per se can be used, polypropene is preferably used. If appropriate, filter paper can then be fitted in the compartments formed in this way, which filter paper, according to a further preferred

aspect, is also shaped by punching or cutting out using suitable tools and fitted in the compartments.

B Compartments formed from a laminate

According to this embodiment, the compartments are formed from a laminate of a plastic and filter paper. The plastic used can be any suitable plastic known per se, polypropene preferably being used. Polypropene is preferable because it is inert towards a large number of test substances used and because it is environmentally friendly and easily degradable.

The laminate is preferably applied to the adhesive strip (1) in such a way that the filter paper forms that side which faces away from the adhesive strip, so that said side is available for taking up the test solutions.

The great advantage of this embodiment in comparison with the prior art is that the filter paper does not have to be fitted in the compartments in a separate production step and that good adhesion between the filter paper and the polypropene compartment is obtained.

With this embodiment of the present invention, pressing of the compartments with the formation of the base and raised edge is preferably carried out in such a way that the raised edge thus obtained, which preferably consists of filter paper on the upper surface, is rendered impermeable to the test solution. C Compartments formed from coated filter paper

According to this embodiment the compartments are formed from filter paper which has been coated with an impermeable coating. In general a liquid-impermeable, in particular a water- or alcohol-impermeable or water/alcohol-repellent coating will be used for this.

In this context, the coating used must be inert towards the test substances used and must not dissolve in these substances. Suitable coatings will be apparent to the person skilled in the art; thus polypropene can be considered, for example.

Highly preferentially, this coating is applied to that side of the filter paper which faces towards the adhesive strip. In this way that side of the filter paper which faces away from the adhesive strip is still available for absorption of the test solutions. A further advantage of this embodiment is that the filter paper can be provided with specific coatings for specific reactive test substances - in particular from the so-called oil series - which react with polypropene compartments or polypropene laminates as described under A and B, or

dissolve the polypropene.

Further advantages of this embodiment are that the compartments shaped from coated filter paper do not have to be provided with a further material for absorption of the test solution and that coating the filter paper with a water-impermeable or water-repellent coating is generally simple and less expensive than the provision of a polypropene/filter paper material.

The test plasters obtained in accordance with the embodiments B and C described above are novel and constitute further aspects of the invention.

The invention therefore also relates to a diagnostic test device for the skin, comprising at least one compartment 3 for introduction of a diagnostic agent, an adhesive strip 1 on which the compartment 3 is accommodated, and also a removable protective strip 4 attached to the same side of the adhesive strip 1 as the compartment 3. the protective strip 4 being provided with an opening 7 at the location of each compartment, one or more rows of compartments 3 being accommodated on or in the adhesive strip 1 and the protective strip 4 having a corresponding number of rows of openings (that is to say at least one row with at least one opening), characterised in that the compartments 3 are formed from a laminate of filter paper and a plastic material, or filter paper which has been coated with an impermeable coating.

In general, the preferred embodiments for these test plasters are the same as described for the above method.

In these diagnostic test devices the compartments 3 preferably comprise a base 5 and an edge 6 surrounding the base. The laminate is preferably a polypropene/filter paper laminate, that side of the compartment which faces away from the adhesive strip 1 preferably being formed by the filter paper.

When the compartments are formed from coated filter paper, the coating is preferably applied to that side of the compartment which faces towards the adhesive strip 1.

The preferred embodiments and advantages thereof will be apparent to those skilled in the art from the above description. The invention is, however, in no way restricted to the embodiments specifically described here and further variations will be apparent to those skilled in the art without these going beyond the scope of the present invention. For instance, it is, for example, also possible to produce the compartments 3 from another material.