Several methods may be used to manufacture so-called front/rear panels of various equipment cases. Metal or plastic are usually utilized as the material for equipment cases. In connection with the manufacture it is often desired to protect the surface of the panel against external conditions that may be harmful to the panel. It is also desired to make markings on the panel to indicate the meanings of the various indi- vidual switches on the panel. Similarly it is desired to make markings on the panel concerning the manufacturer or a possible hazard to the user.

A prior-art method for realizing said protection and markings is depicted in outline in Fig. 1 describing a so-called powder painting method and, in association with it, silk-screen printing of text/graphics on the surface of the powder-painted panel. The manufacturing process, in rough outline, is as follows: A sheet panel of a desired shape is first manufactured, step 10, wherein holes/perforations of a desired shape are made in step 11. Burrs possibly left by the perforation are removed in step 12.

Subsequent to deburring, in step 13, the sheet panel is bent into the shape desired, if necessary. In step 14 the panel is chromated, if required by the material of the sheet panel, where chromation is necessary in order to protect parts of the sheet panel in its future conditions. In step 15, those parts of the sheet panel that are not to be ex- posed to the powder painting process, are covered with paint guards. Powder paint- ing proper takes place in step 16 where powder paint of the desired color attaches to the exposed parts of the sheet panel. In step 17 the paint guards are removed, and in step 18 possible paint burrs left by the painting process are removed. In step 19, silk-screen printing is utilized to print the desired text/graphics in the desired colors onto the sheet panel. In the oven, step 20, the heat makes the text/graphics attach permanently onto the surface of the panel.

Another method is known in which the powder painting proper and silk-screen printing on the painted surface are replaced by a surface film attached to the surface

of the sheet panel. In this method, too, steps 10 to 13 take place first, after which the text/graphics are printed on a separate at least partly transparent surface film. Either before or after the silk-screen printing, suitable holes are made on the surface film on positions corresponding to the through holes in the sheet panel. The surface film thus manufactured is attached to the sheet panel in such a manner that the perfora- tions in both the film and the sheet panel match as precisely as possible. However, as the perforations of the surface film and sheet panel and the edges thereof will not match perfectly, this manufacturing method, too, requires the aforementioned chromation process to protect areas outside the surface film if the panel is made of a ferrous material.

Both prior-art manufacturing methods described above have several drawbacks. The methods comprise a number of separate work stages requiring precision, which makes the manufacturing time of the product long. The manufacture of the product is expensive as the equipment and machines used in the processes are large and costly. Moreover, the recycling of chromated parts is problematic because chro- mium is a toxic substance. The painting process itself also involves disadvantages relating to occupational and environmental safety. As was mentioned above, part of the materials used in the manufacturing process must be handled as hazardous waste, requiring great care and thus causing extra costs. Furthermore, the powder painting process is susceptible to various disturbances which may result in un- wanted color variation in the object to be painted, which, in turn, may result in the whole product being rejected. When a separate surface film is used instead of pow- der painting, the alignment of the perforated surface film to its precise position is problematic with large pieces, and especially in the case pre-bent panels it is ex- tremely difficult to attach the surface film to its correct position. In addition, it is difficult to make the dimensions of the perforated surface film accurate enough so as to cover all through holes and sheet panel edges so well that there will be no need to chromate the parts in question if a ferrous panel material is used.

Publications EP-A-48107, EP-A-591531 and JP8058017 disclose solutions for attaching a surface film containing colors and printings onto the surface of a metal plate. After the surface film has been attached, the metal plate can be bent into the desired shape. In all these solutions, the attachment of the surface film requires that the surface film or the plate to be coated be heated, whereby the methods consume a lot of energy and are complex in their technical implementation. Furthermore, these solutions are intended primarily as coating solutions for metal plates, such as

building materials, to be installed outdoors, where the coating must have a really high mechanical and chemical durability.

From publication JP62144984 a solution is known in which a primer is first applied onto the surface of a metal plate, after which a surface film containing patterns and printings is attached to the plate. The metal plate is then worked in the manner required: bent and perforated, for instance. After working the metal plate, the sur- face film is removed and the patterns and printings stay on the metal plate. The drawback of this solution is that the print does not have a protective surface layer wherefore it is easily worn and damaged.

An object of the invention is to provide a new solution by means of which it is pos- sible to reduce said disadvantages and drawbacks associated with the prior art.

The method according to the invention is characterized by what is specified in the characterizing part of claim 1.

The surface laminated panel according to the invention is characterized by what is specified in the characterizing part of claim 11.

Advantageous embodiments of the invention are presented in the dependent claims.

The principal idea of the manufacturing method according to the invention is as follows: The text/graphics to be attached to the substrate are printed on a suitable film which is at least partly transparent. Several possible printing patterns may be combined on the same surface film. The surface film is attached, subsequent to the printing process, to a kind of pre-panel, on which preliminary surface treatments have been made if necessary, and after the surface film has been attached, the pre- panel can be cut into parts, thus producing several surface laminated panels proper.

The substrate is perforated only after the surface film has been attached to the pre- panel so that the edges of the perforations will automatically be positioned cor- rectly. Furthermore, the surface film wholly covers the edges of the panel if re- quired. Thus there is no need at all for separate protection of the perforations and panel edges.

An advantage of the invention is that surface film lamination can be realized in large areas on an unbent substrate. The manufacturing process according to the in- vention is thus short and has low costs. Attachment of the surface film does not

require heating, so the invention additionally is energy-conserving and technically easy to implement.

Another advantage of the invention is that from the manufacturing process it is pos- sible to leave out work stages in which substances classified as hazardous waste/environmental poison are used.

A further advantage of the invention is that by means of the method it is possible to achieve large surfaces of uniform quality in desired colors.

A further advantage of the invention is that different patterns needed in the product can be manufactured in the desired color.

A further advantage of the invention is that there is no need for separate protection of the edges/perforations of the piece using some other method.

A further advantage of the invention is that the method can be used to manufacture sheet panels that can be bent into the desired shape without breaking the surface film.

The invention is described in detail in the following. The description refers to the accompanying drawings in which Fig. 1 shows a prior-art manufacturing method in outline, Fig. 2 shows a manufacturing method according to the invention in outline, Fig. 3a shows by way of example a planar surface laminated embodiment ac- cording to the invention, and Fig. 3b shows by way of example a surface laminated embodiment according to the invention which has been bent to shape.

Fig. 1 was discussed in connection with the description of the prior art.

Fig. 2 shows by way of example the main steps of a manufacturing process accord- ing to the invention. In step 21, the desired texts/graphics are printed on the selected surface film. If necessary, a desired background color may also be printed on de- sired locations of the surface film. The surface film may be transparent, colored with a desired color or just partly transparent. The material of the surface film may be advantageously either polycarbonate or polyester, the mechanical properties of

which are good as regards wear resistance. The material of the surface film may also be some other commercially available plastic, and it may be selected on the basis of ambient conditions, for example. In step 22 the surface film is attached ad- vantageously by means of lamination onto the substrate which has been already sur- face-treated, if necessary. The material of the substrate is metal or plastic. Attach- ment of the surface film may be carried out in a number of ways, but advanta- geously it may be done using a dual-sided glue film. In that case, the glue film is first attached to the surface film by its one surface by removing the protective layer from the glue film and pressing the glue film against the surface film. In the second step, the protective layer is removed from the other side, too, and the glue film and the surface film attached to it are pressed against the substrate. In some embodi- ments according to the invention the surface film is attached to the other side of the substrate as well. Another advantageous method of attachment of the surface film is to arrange first for a layer of glue on the surface of the substrate or surface film e. g. by spraying or brushing and then press the surface film against the surface of the substrate.

The perforations and holes possibly needed in the finished panel are made in the substrate in step 23 and the panel is cut into the final size. The perforations can be made using any commercially available technology, such as panel working center, perforating tools, machining, laser cutting, water jet cutting, etching and so forth.

The perforations and holes are well and precisely aligned. There is no need for a separate perforation edge protection process after the perforation, since the surface film covers the substrate surface right to the edge of the perforations. The outer edges of the substrate are similarly wholly protected, whereas in manufacturing processes according to the prior art they always have to be separately protected e. g. by means of chromation subsequent to perforation.

In step 23, burrs possibly left by the perforation and final cutting of the substrate are removed. If the final shape of the panel is planar, it requires no further work stages.

In step 24, if necessary, the panel, which has been laminated at least on one surface, can be bent into the shape desired. The bending will not detach the film from the substrate in any direction. Thus the method according to the invention can be used to manufacture planar panels, panels bent to shape, or the panel may be bent into a hollow so that it may function as such as an equipment case.

The manufacturing process according to the invention can be automated further than the prior-art powder painting and silk-screen printing process. The manufacturing process according to the invention achieves considerable savings in manufacturing costs compared with the multi-stage manufacturing process according to the prior art.

Fig. 3a shows by way of example a planar embodiment manufactured using the method according to the invention and Fig. 3b shows an embodiment bent into shape. Fig. 3a shows a completely surface laminated panel comprised of a substrate 31 and a surface film 32 attached onto one side thereof. In this embodiment the film is made of polycarbonate or polyester. The necessary perforations 35 are made in the panel in such a manner that the surface film 32 extends to the edges of the perfo- rations in the substrate 31. The necessary patterns, texts and other graphics 33 have been printed on the surface film 32 before the surface film 32 is attached to the sub- strate 31. Markings are printed on the surface film 32 advantageously using silk- screen printing or some digital printing technique. If necessary, the bend 34 in the panel can be made after the working of the holes 35, as shown in Fig. 3b by way of example. The texts/graphics 33 have been defined and positioned already at the design stage of the product so that after the cutting of the holes 35 and associated work stages and the bending of the panel the case is practically finished.

Advantageous embodiments according to the invention were described above. The invention is not limited to the embodiments described as examples. The inventional idea may be applied in many ways within the scope defined by the claims.