EP2540487A1 - Pressed sheet or continuous ribbon with a sandwich structure - Google Patents

Abstract

The sheet (1) or band has a carrier body (10) connected with a stamping body (11) or copper layer, by a surface structure (13) using an adhesive agent (12) i.e. high temperature adhesive. The carrier body and the stamping body form a sandwich structure. The adhesive agent is doped with metal powder. The adhesive agent is tempered in temperatures above 250 degree Celsius for releasing the carrier body and the stamping body. The adhesive agent contains a magnetic film made of silicon elastomer with additives of high temperature resistant magnetic materials. An independent claim is also included for a method for manufacturing a pressed sheet or continuous band.

Description

The invention relates to a press plate or endless belt for embossing materials, in particular wood materials or plastic materials, by means of a surface structuring and a method for producing the press plates or endless belts according to the invention.

Press plates or endless belts are required to press wood-based panels with decorative and / or overlay papers. Here, a full-surface coating of wood pulp plates with Aminoplastharzfilmen, also called Duroplastharze. Processing takes place, for example, in one-day short-cycle presses or multi-daylight presses. The finished press plates or endless belts are used in the presses to impart a desired surface structure to the wood materials to be produced. Preferably, in this case a congruent embossing is preferred. This means that a decor paper used is used with a conformable press plate or an endless belt, so that the structure of the decorative paper can be embossed into relief in the surface. The structures used in this case may be of natural origin, for example the imitation of a wood pore structure or rock surface, it is also possible to produce any desired structures according to customer requirements.

The decorative and overlay papers used are preferably made of thermoset resins, which pass through pressure and temperature in the press line in a liquid form and enter into a solid connection with the wood material with increasing degree of crosslinking, with simultaneous increase in resin viscosity in the final state. The thermoset resins used include melanin, phenolic or melamine / methylated resins, which have been found to be particularly suitable. During the pressing process will under pressure and temperature, the melamine resin liquid and there is a further polycondensation instead. Press time and temperature determine the degree of crosslinking of the melamine resins and their surface quality. After the pressing time, the melamine resin has the desired degree of crosslinking and has gone into a solid phase, which is achieved by the simultaneously textured embossing of the melamine resin surface a lifelike, the surface of the embossing tool reproducing surface design.

According to the state of the art embossing tools are produced in the form of press plates or endless belts made of steel sheets, which receive the required surface structure by appropriate processing. For this purpose, various methods are known, for example, by applying a screen printing process to provide an etch resist to make a subsequent etching of the press plate. The sheets used in this case have a very large format, so that it depends on a very precise processing and in particular a cover-compliant further processing, as far as several steps are necessary. Several work steps always occur when particularly deep structures have to be etched and for this purpose several etching operations with a previously applied etching resist are required. In the etching processes, all regions which are to form the raised surface structure later are covered by the mask, so that a surface etching takes place only in the regions which can be attacked directly by the etching liquid. The etched out areas then form the valleys of the desired structure, wherein after completion of the etching process, the surface is cleaned and in particular the mask is removed.

Alternatively, it is possible to apply a photographic layer, which is then subjected to an exposure to the press plates or endless belts after the final development of the photographic layer Filling a part of the photo-layer as an etching resist to undergo an etching process. The reproducibility of the masks produced in this way is very difficult and problematic because the Ätzresistschichten to be applied must always be placed exactly in the same position when particularly deep structures are to be etched.

Furthermore, it is known from the prior art, instead of a screen printing process to produce a mask by a wax job or alternatively to use a UV varnish, which is printed by means of a digital printing process directly on the press plates and endless belts to be processed. After etching, which may need to be repeated several times, particularly deep structures can be achieved here, which are congruent by the application of the digitized printing process to a high degree.

As a further alternative, it is known from the prior art to produce the required structure directly on the surface with the aid of a laser method, wherein the depth structures to be produced are produced directly with the aid of a laser. Also in this method, the exact control of the laser is made with the help of a digital printing technology, so that after completion of the press plates or endless belts these have a 100% match with the decor papers. Only by the recently developed process for Oberfiächenstrukturierung the required level is achieved in order to produce a high degree of conformity of the required press plate structures with the decorative papers.

After completion of the press plates or endless belts, these further process steps can be subjected to achieve special effects, for example, to influence the gloss level. The degree of gloss can be made from dull, semi-glossy or glossy, so that after the pressing process the wood-based panels have a desired surface structure have a glossy effect that comes very close to that of natural grown natural wood. Preferably, wood pore structures are produced by these methods, but equally imaginative surface designs can be made or a leather imitation, tiles or natural stone surfaces can be reproduced. Any conceivable structure can be produced by this method.

Depending on the intended use of the manufactured Hioizwerkstoffplatten, for example in the wall area, but also in the floor area, the overlay papers with abrasion-resistant particles, such as corundum, be doped, so there is a high abrasion resistance for the end user. However, this abrasion resistance leads to negative effects on the used press plates or endless belts. After each pressing operation and opening of the presses, a relative movement takes place between the processed wood material with the pressed surfaces and the press plate or endless belt, so that a gradual deterioration of the surface structure occurs. In such a case, it is necessary to completely rework the press plate or to replace it with a new press plate. In the coating, for example of HDF (high-density fiberboard) plates, the press plates must be refurbished after a relatively short period of use. The reason is the high proportion of corundum which is used in the melamine resin films for abrasion resistance, whereby the chrome-plated surfaces are abraded relatively quickly. The production of a press plate is very complex and costly, with a scrapping is provided at the end of the term. Among other things, this is due to the fact that the blanks of the press plates or endless belts are first provided with a direction-free intermediate sanding and additionally polished before the surface structuring, before a new structuring can take place, so that gradually after several reworking the thickness of the press plates or endless belts no longer required level reached. Only then does the complex structure production take place, for example according to the classical etching methods, Application of the etch reserve, etching with, for example, ferric chloride, degree of gloss production by, for example, sandblasting and subsequent surface sealing, for example chromium plating, or alternatively by the production of the structure by means of a laser engraving. Likewise, in mechanical damage most of the press plate vaults would have to be completely abraded and reworked. The result of this is that the relatively expensive base press sheets only remain conditionally usable and must be scrapped after approximately four to six work-ups, since they become too unstable due to their thickness and can not be fixed uniformly in the press installation.

The invention has for its object to propose a novel press plate or endless belt for a single or multi-day presses, which allows compared to conventional press plates or endless belts inexpensive production and longer periods of use of the carrier plates.

According to the invention, the object is achieved by providing a carrier body which is connected to an embossing body with a surface structuring via an adhesive. Further advantageous embodiments of the invention will become apparent from the dependent claims.

Compared to the previous method with a base material which forms the press plate or endless belt and which is provided with a surface structuring, the invention proposes to use a carrier body which is connected to an embossing body via an adhesive, wherein only the embossing body has a surface structuring. Thus, the embossing body can be produced inexpensively regardless of the carrier body and are connected by the adhesive to the carrier body insofar that a proper use for single or multi-day presses can be done. After wear of the surface structuring, there is the possibility of the embossing body of the Remove carrier body again and replace it with a new embossing body. The material required in this case is significantly reduced, because the carrier body can be used over and over again and only an extremely thin coating in the form of an embossing body must be replaced. For this purpose, the carrier body, consisting of, for example, stainless steel, for example AISI No. 630, AISI 410 or AISI 304 or brass according to the prior art, is first prepared. Instead of the usual surface structuring of the press plate or endless belt by means of an etching technology or a digital laser engraving, the embossing body is produced independently of the carrier body, that is provided with a surface structure, then the support body and the embossing body with the aid of an adhesive are intimately and reversibly connected, so that a sandwich structure is created. This sandwich structure has the particular advantage that in later work-up the expensive carrier body is retained and only the upper embossing body has to be renewed. By this measure, production and raw material costs are saved to a considerable extent. Furthermore, the embossing body, which is usually much thinner and cheaper than the carrier body, already prefabricated and placed in storage for each customer. This saves time and significantly shortens delivery times.

As an adhesive, for example, an adhesive, in particular a high temperature adhesive in question, which is placed or applied in the form of an adhesive film or in spreadable form on the carrier body and / or embossing body.

In order to increase the heat transfer value of the press plates or endless belts according to the invention, heating of the material plates in the single or multi-day presses, the adhesive is doped with a metal powder, for example, copper, brass, aluminum or Iron. The adhesives used in this case can be used up to temperatures of 250 ° Celsius, so that premature detachment of the embossing, for example, at the temperatures occurring for the production of the material plates of about 220 ° does not occur. At the same time, however, the adhesives can be tempered above temperatures of 250 °, so that the embossing body can be detached from the carrier body without further ado.

Alternatively, there is the possibility that the adhesive consists of magnetic materials or of adhesives doped with magnetic materials. Such adhesives are always suitable when the carrier body and the embossing body are both made of steel and thus have magnetic properties. To connect the carrier body and embossing body, for example, a high-temperature resistant magnetic film can be used, which ensures the intimate connection between the two bodies as an adhesive. As far as a magnetic sheet is used, for example, a crosslinked silicone elastomer is used, with the addition of high temperature resistant magnetic materials, for example SamarinlKobald, aluminum / nickel / cobalt, neodynium / iron / boron, barium or strontium ferrites or soft ferrites, such as manganese / zinc. All of the aforementioned permanent magnet materials lose very little of their holding power, about 15 to 20% at the existing operating temperatures of about 220 °. The proportion of additional magnetic materials depends on the respective desired adhesive force of the materials, less the loss of adhesion at the respective operating temperature and the total weight of the embossing body. However, these boundary conditions can be taken into account without problems, so that even with the help of a magnetic film, a permanent, but reversible connection between the carrier body and the embossing body can be produced. At the same time, the magnetic film offers the possibility of separating both bodies from each other without residue, so that a rapid exchange of the embossing body can take place in the event of wear.

Insofar as high-temperature-resistant adhesives are to be used, modified acrylate adhesives are suitable, for example PMMA adhesives poly (methacrylic methacrylate, PMI poly (methacrylimide), MBS poly (methacryl methacrylate) styrene butadiene, UP unsaturated polyester resins - DAP diallyl phtatlate, Aromatic polymides, silicone resins, epoxy resins, ACM acrylate rubber or FKM fluoro rubber adhesives Some of these adhesives are particularly suitable because they lose their adhesiveness with a solvent and thus also allow a clean separation of the carrier body and the embossing body.

For the production of the embossing body known from the prior art, for example, etching technology or laser engraving, used, these preferably have only a small thickness and thus can be processed much less complicated. One way to do this is to clamp a stamping body in the form of a metal foil or thin sheets on a steel cylinder for Oberflächenstruktur structuring, the diameter of the steel cylinder is adaptable to the maximum width of the press plates, so after completion of the embossing body and after removal of the Stahlzylindem this with the Carrier body can be connected.

As far as metal foils or thin sheets or other materials, such as steel or brass are used, they can be clamped onto the steel cylinder and then engraved accordingly, followed by the above steps until the completion of the surface structuring. The metal foils or thin sheets produced in this way are then cut to the size of the carrier body and connected to it, so that the press plate or endless belt is available for further use.

Alternatively, it is possible to galvanize a ballard skin of about 100 microns on a copper base layer, wherein between the base layer and the ballard skin, a release layer can be arranged so that a later lifting of the ballard skin is possible. With ballard skin, gravure refers to a peelable layer of copper on a gravure cylinder. The gravure cylinder made of steel covers a 2 mm thick base copper layer on which a second copper layer, the so-called ballard skin, is galvanized. Between the 100 μm thin ballard skin and the main body lies the separation layer, so that the ballard skin can be easily removed after engraving and replaced with a new one. After galvanizing the copper layer, it can still be polled and then the surface structuring takes place, for example by means of a laser. The finished engraved surface is then coated to increase the wear resistance galvanic with a chrome layer, which can follow in individual cases further processing steps, for example, to influence the gloss level. To remove the ballard skin this is usually opened at a Stlrnende of the steel cylinder and then pulled down by pliers and removed. The steel cylinder itself can then be reused for the next production.

For the carrier body, a metal is preferably used, for example stainless steel, AISI No. 630, AISI 410 or AISI 304 or alternatively a brass sheet. In contrast, the embossing body may consist of copper, brass or stainless steel, wherein the thickness is freely selectable depending on the required structure depth, preferably 0.3 to 3.0 mm, particularly preferably 0.3 to 1.5 mm.

The main advantages of the newly designed press plates or endless belts consists in a later separation of carrier body and embossing body, the embossing body is exposed to significantly higher wear, as the carrier body, the carrier body can therefore be used several times and is repeatedly reconnected with an embossing body, preferably using pressure-sensitive adhesive are used, which allow an intimate connection. Alternatively, a connection can be made with the aid of magnetic materials, in particular a magnetic adhesive film, in order to achieve the desired advantage.

• der Prägekörper durch ein Ätzverfahren, Walzverfahren, Pressverfahren oder eine Lasergravur eine Oberftächenstrukturierung erhält,
• der Träger- und/oder Prägekörper mit einem Haftmittel versehen wird und
• beide Körper, Trägerkörper und Prägekörper, miteinander durch das Haftmittel verbunden werden.

A further object of the present invention is to provide a method for producing the novel press plates or endless belts. To save material and costs, it is provided that the production of a press plate or endless belt for embossing of materials, in particular wood materials or plastic materials by means of a carrier body and an embossing body takes place, wherein

• the embossing body obtains a surface structuring by an etching process, rolling process, pressing process or a laser engraving,
• the carrier and / or embossing body is provided with an adhesive and
• Both body, carrier body and embossing body, are connected to each other by the adhesive.

The method shown is characterized by a special economy and also allows multiple Wlederverwendung the carrier body, which is exposed to almost no wear. The embossing bodies used in the form of a thin metal foil or a thin sheet can be reversibly removed from the support body, so that a workup of the support body is required only to a small extent. As a result, considerable processing time is saved and also a considerable savings potential is achieved through the use of thin sheets or metal foils with a surface structuring, in particular due to the fact that the materials to be processed, wood materials with overlay and decorative papers cause wear of the embossing body. Of the particular advantage results from the reversible connection of carrier and embossing body, wherein an adhesive compound or a magnetic compound can be used.

A further advantage of the press plates or endless belts according to the invention is that less high-quality metals are used for the carrier body and thus the production costs can be significantly reduced. So far, it has been necessary to use high-quality stainless steels, which make it possible to carry out the necessary surface structuring. However, there is no need to be taken into account, since the surface structuring takes place only on the surface of the embossing body.

The invention will be described again with reference to two figures.

Fig. 1

in einer perspektivischen Ansicht ein hergestelltes Pressblech mit einer Holzporenstrulctur und

Fig. 2

in einer vergrößerten Schnittdarstellung den Aufbau des Pressbleches.

It shows

Fig. 1

in a perspective view of a manufactured pressed sheet with a Holzporenstrulctur and

Fig. 2

in an enlarged sectional view of the structure of the press plate.

FIG. 1 shows a perspective view of an inventive press plate 1, which is flat in the embodiment shown. In the case of an endless belt, however, this embossing tool can also be curved. The press plate 1 shows a grain 2, which is modeled, for example, the shape of a wood pore structure. However, it is conceivable that other grains or other surface textures in this way by the inventive method and the necessary etching or laser process is made.

FIG. 2 shows in an enlarged side view a part of the front edge region of the press plate 1 and the surface structure located thereon. As in particular from FIG. 2 As can be seen, the press plate 1 consists of a carrier body 10, an embossing body 11 and an adhesive 12. The adhesive 12 allows, as far as it consists of an adhesive or a magnetic material, in particular a magnetic film, a detachment of the embossing body 11 from the carrier body 10. The carrier body 10th Thus, it can be reused while, on the other hand, a worn embossing body 11 is replaced. The existing on the embossing body 11 surface structuring 13 is prepared for example by means of known etching technologies or a laser engraving, wherein a layer thickness of the embossing body of 0.3 to 3 mm, preferably 0.3 to 1.5 mm is used. For the production of the embossing body 11 it is possible aufzuspannen this on a steel cylinder to produce the surface structure 13 by an etching technology or a laser process and after preparation and further treatment, such as chrome plating and other steps to influence the gloss level after removal from the steel cylinder, with the help the adhesive layer 12 to connect to the carrier body 10.

A particular advantage of this invention Pressbleche.oder endless belts is that for the carrier body 10 less high-quality metals must be used and thus the production cost can be significantly reduced. So far, it has been necessary to use high-grade stainless steels, which make it possible to carry out the necessary surface structuring. However, there is no need to be taken into account, since the surface structuring takes place only on the surface of the embossing body.

LIST OF REFERENCE NUMBERS

1

press plate

2

Grain

10

support body

11

stamping body

12

adhesives

13

surface structure

Claims (15)

Pressing plate (1) or endless belt for embossing materials, in particular wood-based materials or plastic materials, by means of surface structuring,
characterized,
that a carrier body (10) is provided which with an embossing member (11) is connected to a Obemächenstruktunerung via an adhesive (12). Press plate (1) or endless belt according to claim 1,
characterized,
that the carrier body (10) and the shaping die (11) form a sandwich structure which is reversibly connected together. Press plate (1) or endless belt according to claim 1 or 2,
characterized,
that the adhesive (12) of an adhesive, in particular high-temperature adhesive. Press plate (1) or endless belt according to one of claims 1, 2 or 3,
characterized,
in that the adhesives (12) are doped with a metal powder, for example copper, brass, aluminum or iron and / or that the adhesives (12) are tempered at temperatures above 250 ° C to release the carrier bodies (10) and embossing bodies (11) and / or that the adhesive (12) consists of magnetic materials or of adhesives doped with magnetic materials. Press plate (1) or endless belt according to one of claims 1 to 4,
characterized,
in that the adhesive (12) consists of a magnetic film, for example a sole-super-elastomer, with the addition of high-temperature-resistant magnetic materials, for example Samarium / Kobald, Aiuminium / Nicket / Kobatd. Neodyn / iron / boron, barium or strontium ferrites or soft ferrites, such as manganese / zinc compounds and / or that as adhesive (12) an adhesive layer in film form or in liquid consistency is rinsed. Press plate (1) or endless belt according to one of claims 1 to 5,
characterized,
that a high-temperature resistant adhesive can be used, for example acrylate adhesive, such as PMMA adhesive poly (methacrylic methacrylate), PMI poly (methacrylimide), MBS poly (methacryl-methacrylate) -styrene-butadiene, UP unsaturated polyester resins - DAP diallyl phtatlate, Aromatic polyimides, Silicone resins, epoxy resins, ACM acrylate rubber or FKM fluorinated rubber adhesive. Press plate (1) or endless belt according to one of claims 1 to 6,
characterized,
that the adhesive ability of the adhesive (12) can be canceled by a solvent. Press plate (1) or endless belt according to one of claims 1 to 7,
characterized,
that the embossing body (11) is designed as a ballard skin, for example as a peelable copper layer. Press plate (1) or endless belt according to one or more of claims 1 to 8,
characterized,
in that the ballard skin consists of metal foils or thin sheets which are mounted on a steel cylinder for surface structuring, the diameter of the steel cylinders being adaptable to the maximum width of the press plates (1) and / or the ballard skin of approximately 100 μm being electroplated on a copper base layer , wherein a separating layer is arranged between the two layers. Press plate (1) or endless belt according to one or more of claims 1 to 9,
characterized,
in that the carrier body (10) consists of a metal, preferably of stainless steel, for example AISI No. 630, AISI 410 or AISI 304 or brass, and / or that the embossing body (11) consists of copper, brass or stainless steel, the thickness being in Dependent on the structure depth is selectable, preferably 0.3 to 3.0 mm, more preferably 0.3 to 1.5 mm. Press plate (1) or endless belt according to one or more of claims 1 to 10,
characterized,
that the surface structuring of the stamping body (11) before the connection to the carrier body (10) is effected and / or that the surface structuring of the stamping body (11) by etching or laser engraving process can be produced. Method for producing a press plate (1) or endless belt for embossing materials, in particular wood fibers or plastic materials, comprising a carrier body and an embossing body, wherein the embossing body (11) is given a surface structuring by means of an etching process, rolling process, pressing process or a laser engraving, - The carrier (10) and / or embossing body (11) is provided with an adhesive (12) and - Both body, carrier body (10) and embossing body (11) are connected to each other by the adhesive (12). Method according to claim 12,
characterized by a reversible connection of carrier (10) and embossing body (11). Method according to claim 12 or 13,
characterized by an adhesive connection and / or characterized by a magnetic connection. Method according to claim 12, 13 or 14,
characterized by an embossing body (11) which has been spanned or galvanized on a metal cylinder for surface structuring and after removal from the metal cylinder is connected to the carrier body (10).

Images