DE2648654A1 - MULTI-LAYERED CARDBOARD FOR BOXES AND FOLDING BOXES AND THE METHOD OF MANUFACTURING THEM - Google Patents

Description

PATENT LAWYERS

DR. WALTER KRAUS DIPLOMA CHEMIST DR.-ING. ANNEKÄTE WElSERT DIPL-ING. SPECIALIZATION CHEMICALS IRMGARDSTRASSE 15 · D-8OOO MÜNCHEN 71 -TELEPHONE 089 / 797077-797078 ■ TELEX O5-212156 kpat d

TELEGRAM CRAUS PATENT

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1393 AW / MY

INDUSTRIA CREDiONESE D ¹ ARTI GRAFICHE snc, Cremona / Italy

Multi-layer cardboard for boxes and folding boxes and methods of making them

The invention relates to a multi-layer cardboard suitable for the production of folding boxes and boxes, as well as a method for their manufacture.

The cardboard that is used today for the production of folding boxes and boxes is called triplex cardboard referred to as they consist of three layers, i.e. a sub-panel or back, which forms the inner layer. The inner layer is in contact with the product contained in the folding box or box. She becomes out of this Reason subjected to several treatments so that it is compatible with the product with which it comes into contact. The paperboard also contains a center panel or filling made of a lower quality material. Generally there is they are made from a material that has been reclaimed paper is obtained. Finally, the paperboard contains a face or top sheet, generally made from expensive, finished materials Cellulosic material with a weight of 60 to 80 g / m is formed and forms a white layer on which the right side of the box or the folding box is printed.

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It has been assumed in the past that one cannot do without this front or top sheet, because it forms a white whole tone or ground "on which one can print, and otherwise the dark background of the raw cardboard what would be seen is what is technically unacceptable.

However, the rising cost of raw materials has made the use of such upper webs for refined cellulosic materials, as stated above, from countries with numerous manufacturers of these materials have to be imported, have to be used, becomes very expensive. This front is still continuous today, so that they are also present in those areas of the boxes or folding boxes where their presence pointless or even unfavorable, namely on the flaps and flaps intended for gluing for a closure of boxes or cardboard, where on the contrary a rougher surface is preferred for better adhesive setting were.

The present invention is based on the problem of the disadvantages with regard to costs and manufacturing processes to eliminate the cardboard currently used for the manufacture of boxes and folding boxes and to create a new type of cardboard with the expensive cellulose front does not exist. The properties of the cardboard should be improved, the cardboard should be uniform Have properties and the white background required for printing on the boxes or folding boxes is to be created by using top and bleaching layers or lightening layers.

The invention relates to a multilayer cardboard for the production of folding boxes and boxes that is characterized by an underside or back, a

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Middle layer with a stiffness and strength that are higher than the usual fillings of known triplex cardboard, and a front cover covering the color of the base cardboard, the front cover being used for printing and for Enables suitability for the intended end use.

The cardboard according to the invention has the same rigidity and the same mechanical resistance or the mechanical strength like the well-known triplex cardboard, because the middle layer is made of a stronger material, such as a power stick, or force masses, are used.

In the case of the paperboard according to the invention, the upper web or front side is replaced by a double cover layer, so that the raw cardboard is suitable for printing.

First, in the paper mill, during the paperboard manufacturing process, a light coat of paint sprayed on or dusted, so that the cardboard is slightly lightened, but not yet the contains the front side required for printing.

For complete coverage of the moiré appearance A second and thicker top layer consisting of white paint is then applied to the raw cardboard. This second Layer of white paint is made by gravure printing in the Cardboard factory applied, as it is only possible with the gravure printing process, a large mass of paint on the cardboard to raise. With the offset or letterpress process you can only apply a thin coating that is not enough to cover the underlying cardboard material.

To produce a degree of whiteness sufficient for printing, it is necessary to apply both layers, i.e. a bleaching or lightening paint or whitewash paint, e.g. a slurry

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chalk paint., and the white paint for covering by gravure.

It is a further feature of the method according to the invention that the white overcoat layer only applies to the Areas is printed where it is required. A stencil is therefore used to keep the parts that are glued together remain free of layers of paint, i.e. the flaps and flaps that close the box or folding box.

The fact that the parts intended for the application of the adhesive are not printed with white topcoat results in addition to the low cost savings and the uniform and functional improvement the paperboard properties and appearance have an additional benefit as the setting time of the adhesive improves because the cardboard remains in the raw state in the areas to be glued.

The cardboard according to the invention can thus very well replace the triplex cardboard which is used for the same purposes v / ird. However, the paperboard according to the invention enables essential Savings in manufacturing costs. There is no need to use expensive, imported, refined materials use, and also the use properties of the paperboard are improved. The cardboard according to the invention can after all methods known to the person skilled in the art can be further processed or further treated.

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Claims (5)

Claims 1. Multi-layer cardboard for the production of folding boxes and boxes characterized by a bottom sheet or back, a middle layer with a stiffness and strength, which are higher than the usual fillings of known triplex cardboard, and one the color of the Base cardboard covering, front cover, with the front cover enables printing and suitability for the intended end use. 2. Multi-ply cardboard according to claim 1, characterized in that that the middle layer is formed from a force mass. 3 · Multi-ply cardboard according to at least one of Claims 1 or 2, characterized in that the front cover from a light layer of a lightening paint and an overlying layer of a white topcoat is formed. 4. Method of making a multi-ply paperboard according to one of claims 1 to 3, characterized in that a light layer of a lightening coating is first sprayed or dusted and that then the layer of white top color is printed on by gravure printing will. 5. The method according to claim 4, characterized in that the white color layer is selectively applied by gravure printing will, i.e. that free parts remain on the cardboard, which are intended for gluing the box or folding box that has been set up ο β. Multi-layer cardboard for the production of boxes and folding boxes, characterized in that they are after a method of claims 4 or 5 has been produced is. 7 · Use of the multilayer cardboard according to at least one of claims 1, 2 or 3 for the production of packaging materials intended for the packaging industry. 1 09 8 18/0795