EP0208751A1

EP0208751A1 - Method for fabricating a substrate provided with a foam stamp

Info

Publication number: EP0208751A1
Application number: EP19860900757
Authority: EP
Inventors: Martina Decker
Original assignee: DECKER VERTRIEBSGESELLSCHAFT MBH
Current assignee: DECKER VERTRIEBSGESELLSCHAFT MBH
Priority date: 1985-01-10
Filing date: 1986-01-07
Publication date: 1987-01-21
Also published as: DE3500552C2; WO1986004100A1; DE3500552A1

Abstract

Procédé dans lequel la surface imprimée du substrat est recouverte d'une couche d'usure. Le procédé prévoit tout d'abord la fabrication d'un produit intermédiaire, lequel est constitué d'un substrat (1), d'une encre d'imprimerie (2) reposant sur ce dernier et susceptible de mousser sous l'effet de la chaleur, et d'une couche d'usure (4) thermoplastique qui le recouvre. Lors de la fabrication dudit produit intermédiaire, on pose et on presse sans soufflures soit une feuille thermoplastique contre un substrat imprimé soit une feuille thermoplastique imprimée contre le substrat, la feuille ayant dans les deux cas un point de ramollissement dans la plage des températures élevées nécessaires au moussage. Ledit produit intermédiaire est chauffé au moins dans la zone de l'encre, cette dernière moussant et la couche d'usure épousant les contours résultant du moussage de l'encre. On laisse ensuite refroidir le produit.Method in which the printed surface of the substrate is covered with a wear layer. The method first of all provides for the manufacture of an intermediate product, which consists of a substrate (1), of a printing ink (2) resting on the latter and capable of foaming under the effect of the heat, and a thermoplastic wear layer (4) which covers it. During the manufacture of said intermediate product, a thermoplastic sheet is placed and pressed without blowing either against a printed substrate or a thermoplastic sheet printed against the substrate, the sheet having in both cases a softening point in the range of high temperatures required. foaming. Said intermediate product is heated at least in the ink area, the latter foaming and the wear layer conforming to the contours resulting from foaming of the ink. The product is then allowed to cool.

Description

Process for producing a substrate provided with a foam print

The invention relates to a method for producing a substrate provided with a foam print, the printed surface of which is covered with a wear layer, the method first comprising the production of an intermediate product which consists of a substrate lying thereon by means of There is a heat effect of foamable printing ink and a covering, thermoplastic wear layer, and further the heating of the intermediate product at least in the area of the printing ink, the printing ink foaming and the wear layer conforming to the resulting contours of the foamed printing ink, and then allowing to cool.

The so-called foam printing process has been described in the relevant literature (cf. ÜS-A-29 20 977) and need not be explained in more detail. It is used in particular in the manufacture of wallpapers, floor coverings or car trim. Printer inks that can be used for the process can be obtained, for example, from Follmann & Co., Munich, Federal Republic of Germany.

It turns out that the printed products are elegant and also accepted as an aesthetically new variant become. The disadvantage, however, is that the foamed and stiffened printer ink is not wear-resistant, but can be rubbed off relatively easily. This disadvantage is not particularly serious for wallpapers; however, it precludes the use of the foam printing process for printing heavily used areas such as book spines.

Furthermore, DE-A-29 15 136 discloses a method of the type mentioned at the outset, in which the wear layer is applied as an additionally coated, transparent layer before foaming, for example made of PVC by means of returning rollers. However, this wear layer is very difficult to apply uniformly and thickly. Your order also requires a high level of mechanical effort, which cannot be realized in medium-sized printers. Nor can the wear layer itself serve as a pressure carrier.

It is therefore the task of specifying a method for producing a substrate provided with a foam print which results in a printed surface which is wear and abrasion resistant and can be produced with relatively little mechanical effort.

This object is achieved in a method of the type mentioned at the outset, in which, in the production of the intermediate product mentioned, either a thermoplastic film is placed on a printed substrate or a printed thermoplastic film is applied to the substrate and pressed on without bubbles , in both cases the film has a softening point in the range of the elevated temperature required for foaming, further that the printing ink and the film are then heated, the film also at least partially softening in the heated state and a continuous, the contours of the Printing ink results in the following wear layer.

Experiments have shown that, depending on the type of film, for example such films as are used in known laminating processes, a glossy or matt, structured, in any case abrasion-resistant surface is also achieved. Suitable foils are, for example, laminating foils with a thickness of 5 to 25 micrometers, which can be selected, for example, from the group of thermoplastics, polyethylene, ethylene-vinyl acetate copolymer, polyvinyl chloride or polycarbonate.

In one process variant, the substrate is first printed and then the unprinted film is placed on it and made to adhere. The latter can be done in particular by using an air-impermeable film, but the substrate is air-permeable or is made air-permeable by perforations. The film is made to nestle by means of a vacuum applied below the substrate. However, it is also possible to electrostatically charge the film or the substrate so that the film presses onto the substrate.

In the other process variant, the

Printed film and placed on the substrate in the non-foamed state of the printing ink. In the latter case, the printed image must of course be mirror-inverted. Here too, the pressure can be assisted by means of a vacuum or by electrostatic charging.

It is also possible to coat the film with an adhesive before placing it on the substrate, so that better adhesion is achieved. However, it turns out that in many cases it is possible to choose films which, by softening themselves, become the adhesive substance be, as is known in the so-called hot glue, so that they stick to the substrate.

Depending on the film material, processing takes place in a temperature range from 120 to 170 ° C. The heating can be carried out by hot air, by infrared radiation or also by microwave radiation if, as is common in many cases, the foamable printing ink contains water.

The product resulting from the method can be, for example, a raised printed spine, a packaging film or a wallpaper. Relief maps, souvenirs or toys can be produced. The substrates can be selected from a large product group, for example made of paper, cardboard, linen, textile raw materials, synthetic fiber fleece or felt. Fabrics with a dense surface, such as wood, metal, glass or high-melting plastics, can also be used. In general, experience with printing foams can be used in general.

Examples are described to explain the process, the attached drawing being intended to explain the process steps. The figures show in detail:

Figure 1 shows the process step before applying the film to a printed substrate;

FIG. 2 shows the method step before applying a printed film to an unprinted substrate;

Figure 3 shows the view of the finished product according to the method. Example 1 (see FIGS. 1 and 3):

A slightly porous piece of linen 1 for a book cover provided with stiffening equipment is printed with an acrylic foam ink in the usual screen printing process (printed image 2). Subsequently, a very thin, thermoplastic film 3 made of polycarbonate with a thickness of 15 micrometers, which is thinly coated with an adhesive 4, is placed on the substrate and the still very flat printing ink and pressed flat with a roller. The substrate with the film is then placed on a vacuum table 5, which generates a negative pressure of approximately -0.1 bar in the region below the substrate. The resulting negative pressure pulls the film onto the substrate so that it clings to the entire substrate surface without bubbles.

This is then done with the vacuum applied

Foaming under elevated temperature (warm air, in a range of approximately 120-170 C. The film has its softening point in this area. The printing ink foams and then takes up an increased volume under the film. Stiffens after cooling again Gas bubbles or faults are not observed at a temperature of 120 - 170 and a processing time of approx. 15 minutes.

Example 2 (see FIGS. 2 and 3):

A thin laminating polyvinyl chloride film 13 with a thickness of 20 micrometers is printed in a multi-color mirror-inverted manner with foamable printer ink (printed image 12). The film is then placed on a perforated paper and cardboard surface 11, the smearing of the printed image being carefully avoided. Again, by applying a negative pressure on a vacuum table 5, the previously lying one with pressure-sensitive adhesive coated film reached on the substrate. Subsequently, the substrate and film are removed from the vacuum table and "baked" at a temperature of 160 and 170 C, ie the printing work is foamed. Here, too, there is a softening of the overlying film 13 and a close fitting of the relief formed (see FIG. 3) also in the area of the elevations 6 produced by printing ink.

The product can, for example, be folded and glued accordingly as part of a package.

Example 3?

A transparent film made of ethylene-vinyl acetate copolymer with a thickness of 25 micrometers and a format of 60 x 30 cm is printed with a non-foaming and a foaming, water-based ink to about 10% of the area. A plastic plate made of a polyamide material is evenly electrostatically charged by rubbing. The printed film is put on. Due to the electrostatic charge, it is pressed evenly onto the surface. The foaming paint is heated to approximately 125 ° C. by means of known microwave heating units, as are known, for example, from canteen kitchens, whereby it expands in the space between the film and the substrate surface and also the film in the contact areas Softening and stretching brings. After the foaming process, which takes about 5 to 10 minutes, the film and substrate are dried again with warm air at about 120. The film melts slightly and sticks to the surface of the substrate. After cooling, the product is ready for immediate use. Example 4:

On a metal, e.g. B. aluminum, or wood, z. B. plywood, surface can be attached to such materials with the help of a printed film, as described in Example 3, wear-resistant patterns. Also suitable as carrier films are films made of other materials, for example polyethylene, polyvinyl chloride or polycarbonate or polymethacrylate, which are generally referred to as "thermoplastics". The printed film is placed on the surface of the substrate and heated with the aid of infrared lights until the printing ink is foamed, which happens, for example, in a range from 150 to 200 ° C. At the same time, melting of the film on the substrate can be observed. The film therefore acts as its own adhesive with respect to the substrate. After complete foaming, post-drying and cooling, a product with a continuous pressure and wear layer results.

In a similar manner, glass, ceramic materials and high-melting plastics can also be printed.

Claims

Claims;

1. A process for the production of a substrate provided with a foam pressure, the printed surface of which is covered with a wear layer, the process initially providing for the production of an intermediate product which, from the substrate lying thereon, is subjected to the action of heat foamable printing ink and a covering, thermoplastic wear layer, and further comprises heating the intermediate product at least in the area of the printing ink, the printing ink foaming and the wear layer conforming to the resulting contours of the foamed printing ink, and then allowing it to cool, characterized in that

»That in the manufacture of the intermediate product mentioned either a thermoplastic film is placed on a printed substrate or a printed, thermoplastic film is pressed onto the substrate and pressed free of bubbles, in both cases the film having a softening point in the range of the foaming has the required elevated temperature that the printing ink and the film are subsequently heated, the film also at least partially softening in the heated state and a continuous wear layer following the contours of the printing ink results after re-cooling.

2. The method according to claim 1, characterized in that the film is air-impermeable and the substrate is air-permeable, and that the film is made to nestle by means of a negative pressure applied below the substrate.

3. The method according to claim 1 or 2, characterized gekenn¬ characterized in that the film is coated with an adhesive before being placed on the substrate.

4. The method according to claim 1 or 2, characterized gekenn¬ characterized in that the film or the substrate are electrostatically charged so that the film presses onto the substrate.

5. The method according to claim 1, characterized in that a paper or textile material, such as paper, cardboard, stiffened linen, plastic fiber fleece or felt, is used as the substrate.

6. The method according to claim 1, characterized in that a substance with a dense surface, such as wood, metal, glass or high-melting plastic, is used as the substrate.

7. The method according to claim 1, characterized in that as a film material, a thermoplastic from the group of polyethylene, ethylene-vinyl acetate copoly er, poly vinyl chloride, polycoronate or polymethacrylate is used.

8. The method according to claim 1 and 1, characterized gekenn¬ characterized in that the film has a thickness between 5 - 25 microns.

9. The method according to claim 1, characterized in that the foamable printing ink is heated by means of warm air or infrared radiation.

10. The method according to claim 1, characterized in that when a water-containing foamable printing ink is used, it is heated locally with the aid of microwaves.