This invention relates to adhesive products. More specifically the invention relates to adhesive products in such forms as tape, sheet material or otherwise. The invention is concerned with the provision of such products having opposite faces provided with adhesive coatings. The invention also may be applied to other products than tape or sheet material, where adhesive coatings on opposite or even just more than one surface are provided. The invention concerns arrangements whereby a product such as a double-sided adhesive tape may be constructed so as to be capable of being assembled in successive layers, or otherwise in co-operating relationship, with the adhesive surfaces serving temi orarily, and perhaps partially, to secure the assembly together, while permitting the layers or articles to be subsequently separated for use.

An example of the application of the invention is to double-faced adhesive tape. The invention may also be applicable to other articles, such as double-faced adhesive pads, in which similar considerations arise.

In the case of double-faced adhesive tape, the presently available product is provided with a layer of release material, such as silicone-coated paper. This layer of release material is provided over one of the adhesive faces of the tape, and the latter adheres thereto so that, upon such assembly, the resultant two-layer product is temporarily provided with only one available surface of adhesive. As a result, the one-sided adhesive product can be assembled in a roll, in just the same way, or in much the same way, as conventional one-faced adhesive tape.

Clearly however such double-faced adhesive tape is unnecessarily expensive and complicated to

manufacture and assemble into rolls due to the presence of the necessary layer of release material, and an object of the present invention is to provide a method and apparatus applicable to double-faced adhesive tape and related products whereby the need for a layer of release material such as silicone- coated paper used in the manner described above is eliminated, or one or more other improvements generally are provided. There is disclosed in EP-A-0 512 153 a labelling product in which two labels each coated on one side only with adhesive are arranged in adhesive face-to- adhesive face fashion so that they can be subsequently peeled apart for use. However, this prior application is concerned principally with adhesive labels, and thus with products which are inevitably provided with adhesive on one face only.

Another prior proposal provides a two-sided adhesive-coated film. This is self-wound adhesive- to-adhesive. The adhesive is formulated so that the adhesion of the adhesive to the adjacent adhesive is smaller than the cohesion of the adhesive and the adhesion of the adhesive to the film, whereby the assembly can be peeled apart at will. This prior proposal suffers from the shortcoming that the adhesives suitable for use in the system are very limited. Moreover, the product is of somewhat limited utility, finding application mainly in relation to flat surfaces, for example in office usage or mounting prints in photo albums etc.

According to the invention there is provided a method and apparatus as defined in the accompanying claims.

In an embodiment, there is provided an assembly of at least two layers of double-sided adhesive tape or sheet material, or other product having at least

two adhesive faces, in which regions of adhesive and release material on successive layers or products are disposed in complementary fashion so as to co-operate in a peelable manner without the need for a release layer.

By providing the regions of adhesive and release material disposed in complementary fashion as described above, there is provided the means for enabling successive layers or products to be assembled in a stacked fashion (such as in a reel of tape, or successive sheets of adhesive material) while being peelable apart when needed for use. This is achieved without the need for a layer of release material coated on paper for example, which would then need to be disposed of.

Also in an embodiment, a double-faced adhesive tape is provided having regions of adhesive and release material on both of its opposite sides A and B. These regions are disposed in complementary dispositions so that when arranged with side A face- to-face with side B in a roll, or otherwise, the areas co-operate in a peelable fashion. In this way, a peelable roll of double-faced adhesive tape can likewise thus be provided without the need for a layer of release-material-coated material, thereby increasing convenience of use and decreasing manufacturing costs accordingly.

In an embodiment, the regions of adhesive and release material are arranged in continuous bands extending lengthwise of the tape or sheet material, and this contributes significantly to ease of production. The bands are disposed alternately across the width of the tape or sheet, for like reasons.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which :

Figs 1 and 2 show, diagra matically, a representation of prior proposals; and

Figs 3 and 4 show, likewise diagrammatically, representations of an embodiment of the invention, Fig 4 being a section on the lines IV - IV in Fig 3.

As shown in the drawings, the prior art proposal shown in Figs 1 and 2 represents an assembly of successive layers of tape and release material such as may be found in a presently available roll of double- sided adhesive tape.

In Figs 1 and 2, the release layer 10 is coated with silicone 12 indicated at "S" the release layer may comprise simply a paper sheet, suitably coated. It is to be understood that the silicone layer on sheet 10 is continuous over both its upper and lower faces.

Likewise, tape 14 has continuous layers of adhesive 16 provided over both its upper and lower faces. The assembly continues with a further release layer 10, likewise having silicone coatings 12.

In use, the prior proposal of Figs 1 and 2 is used as follows. First, a strip of tape 14 with its adhering release layer 10 is peeled from the next lower layer of release material and tape. The thus, exposed surface layer of adhesive 16 is then used to adhere the assembly to the required article. Then, the redundant release layer 10 can be peeled away exposing the upper adhesive layer 16 on the tape which is then available for use, to adhere to a further article.

Turning now to the embodiment of the invention shown in Figs 3 and 4 it will be seen that the successive layers of tape or sheet material 20 have layers or regions or bands of adhesive 22 and release material 24 on their opposite surfaces.

Thus, adhesive co-operates with release material

and vice versa in a peelable fashion. After peeling, the adhesive bands are available for adhesion, and their adhesive effect is not prevented by the adjacent regions of release material 24. As shown in Fig 4, the release material 24 is arranged in alternate bands, strips or stripes with the adhesive 22, across the width of the tape 20. By disposing these bands or strips alternately and in complementary fashion on opposite sides of the tape, successive layers in a roll of tape co-operate in the peelable fashion indicated in Fig 4.

Further details of the construction and arrangement and mode of manufacture of the regions of adhesive and release material are to be found in our above-mentioned European patent specification EP-A-0 512 153, to which reference is directed as a prior disclosure, and from which the entire disclosure is incorporated herein, likewise by reference. However, the present invention is not limited to any particular construction or arrangement of the regions or bands or areas of release material and adhesive, these being simply disposed in the complementary relationships defined herein.