"Improvements to binding files".

Abstract: Improvements to binding files of the type of which at least the back is made of a porous or nearly porous material, for instance cardboard, and whereby this back is provided at its inner side with an amount of glue which can melt under the influence of heat, characterized in that between the back (4) and the glue (6) is provided a layer of non-porous or hardly porous material (5).

Description: The present invention relates to improvements to binding files, more particularly binding files of the type which consist of a front sheet, a rear sheet, a back, whereby at least the back is made of a relatively porous material, for instance cardboard and on the inner side of the back an amount of glue which can melt under the influence of heat. In the present case under binding file is understood both proper files, and parts thereof, for instance parts which mainly consist of a back of the file with small projections to which a front sheet and/or a rear sheet can be attached. In order to bind a bundle of sheets, documents or such-like by means of such known binding files, these sheets or such-like are placed between the front and the rear sheet of the file so that they are brought with one edge in contact with the above-mentioned amount of glue. Subsequently the whole is put vertically, with the back downward, on a heating element, in such a manner that the afore-said glue is brought to melting and the sheets to be bound penetrate into this layer of glue so that, after the binding file has been removed from the heating element and the glue has solidified, the afore-said sheets or such-like are firmly held in the binding file. A serious disadvantage of binding files of which at least the back is made of a porous material, for instance cardboard, is the fact that when the glue is brought to melting, it is partly absorbed by the porous material, because the glue penetrates in the pores of this material which has for a consequence that the amount of glue, which remains available for the real fastening of the sheets or such-like, is reduced. The present invention aims at excluding this disadvantage and to avoid that, in order to obtain good binding results, a greater amount of glue must be applied in order to compensate the amount of glue which penetrates in the material of which the back is made. It is known to provide a layer of material between the back of the binding file and the amount of glue. This is the case in FR 2.276.944, DE 2.820.544 and US 5.120.176. The invention consists of improvements to binding files, whereby the abovementioned problem is solved in an advantageous manner. To this end, the invention consists of improvements to binding files, of the type of which at least the back is made of a porous or nearly porous material, for instance cardboard, whereby this back is provided at its inner side with an amount of glue which can melt under the influence of heat and whereby between the back and the glue a layer is provided, characterized in that the layer consists of a non-porous or hardly porous, synthetic material, this layer providing that the glue cannot penetrate in the back and the whole thickness of glue remains availablle for binding the sheets or such-like. In order to better show the characteristics of the invention, the following preferred embodiment is described as an example only without being limitative in any way, with reference to the accompanying drawings, in which: figure 1 represents a perspective view and in an unfolded condition, of a binding file according to the invention; figure 2 represents a section according to line II-II in figure 1; figure 3 represents a view to a larger scale of the part which is indicated in figure 2 with F3. The present invention concerns a binding file 1 which is made of a front sheet 2, a rear sheet 3 and a back 4, whereby at least this back 4 is made of a porous or relatively porous material, such as for instance cardboard and whereby this back 4 is provided with a layer 5 of synthetic material, for instance polyvinylchloride, to which the proper glue layer 6 is applied. The layer 5 will be provided at least at one side with an adhesive layer with which this strip is attached to the back 4. In such a way it is obtained that between the porous material, of which the back 4 is made, and the layer of glue 6 a layer of material 5 is provided which is non-porous or hardly porous so that the glue cannot penetrate therein and the whole thickness of glue remains available for binding the sheets or such-like without having to apply for that purpose a special thicker layer of glue 6. The present invention is by no means limited to the embodiment described above and represented in the drawings, but such binding file or a part of the binding file of which the back of the file to be made consists of a porous or relatively porous material such as cardboard, can be made in various forms and dimensions while still remaining within the scope of the invention, as defined in the appended claims.

Claims: A binding file of the type of which at least the back (4) is made of a porous or nearly porous material, for instance cardboard, whereby this back (4) is provided at its inner side with an amount of glue (6) which can melt under the influence of heat and whereby between the back (4) and the glue (6) a layer (5) is provided, characterized in that the layer (5) consists of a non-porous or hardly porous, synthetic material, this layer (5) providing that the glue (6) cannot penetrate in the back (4) and the whole thickness of glue (6) remains availablle for binding the sheets or such-like. Binding file according to claim 1, characterized in that the synthetic material is polyethylene. Binding file according to claim 1 or 2, characterized in that the layer (5) of synthetic material is sticked to the back (4) of the binding file (1).

Inventors: PELEMAN GUIDO, PELEMAN, GUIDO
Applicants: UNIBIND CYPRUS LTD, UNIBIND (CYPRUS) LIMITED
Application year: 1998
Main classification: B42D3
IPC codes: B42F7, B42D3