DE3215684A1 - METHOD FOR PRODUCING DECORATIVE PANELS - Google Patents

Description

METHOD OF MANUFACTURING DECORATIVE PANELS

The invention relates to a method for producing decorative panels.

Decorative covering materials come in many different Designs available and can be made of plastic, natural materials or combinations thereof, for example exist. The material can have a smooth or profiled wear surface, with the latter alternative is preferred in most cases for both practical and aesthetic reasons. Profiled Material has a multi-dimensional, high-contrast appearance, which can only be achieved through a flawless Synchronization of pattern image and relief is available. A common surface embossing, that of the plastic surface is imposed and does not match the occurring print pattern, cannot produce this effect.

In addition to all wood imitations made of plastic, excellent cork imitations have been used for several years a relief surface and can, as well all pure natural substances are used for both wall and floor coverings. Covering materials made from a combination of natural material and plastic in the form of a relatively thick one covering the natural material There are plastic films, but only have a smooth wear surface available because there is no known procedure

through which a thick wear layer made of plastic can be attached to cork, for example, without the relief is leveled at the same time.

Smooth cork floor panels have been manufactured for a long time, consisting of a wear layer made of plastic, consist of a decorative layer, an elastic layer and an underlayer. The wearing layer exists preferably made of calendered or coated plastisol made of transparent, plasticized PVC with good Wear resistance and stain resistance. The elastic layer consists of one made by rotating or splitting Arch made from cork granulate blocks. If necessary, this sheet is prelaminated with a thin, refined decorative cork veneer. The lower layer serves as a mechanical stress equalizer, and this layer or a further counter-layer to the wear layer makes it more difficult for the plates to sink in and slows it down Moisture diffusion from the sub-floor. For the last-mentioned layer, plasticized PVC film is used, which has the same strength module as the wear layer or a higher one. In the finished floor construction a balance of forces is brought about, and the The flatness of the panels is ensured.

Cork is an excellent material in the present context, but because of its extraordinary Porosity and its large air content causes significant difficulties in the manufacture of panels. As a natural product, cork is also afflicted with numerous defects, which take the form of larger ones or make smaller cavities or depressions visible, which are not accepted in the finished plate can. This means strict selection and costly scrap quantities in production. Especially thin cork veneer panels with low compression are mostly full of holes that have to be filled before the film covering can be applied.

The wearing layer is usually connected to the layer underneath by pressure gluing. Attempts have also been made to manufacture cork sheets in a continuous process with lacquering and roller gluing, but without much success.

In summary, it can be said that a natural substance in combination with a wear layer made of plastic film only occurs in the form of a cork plate with a smooth, covering film layer.

The invention is based on the object of using a new manufacturing process to produce both smooth as well as to enable profiled panels and sheets of this type that. for floor and wall cladding purposes suitable and, thanks to the low reject rates, are cheaper than the products known up to now.

The solution to this problem is achieved with the measures and means specified in the patent claims.

The inventive method is primarily characterized in that a completely new type of a Backing layer is used, which is made of granulated cellulose material consists in a die made of meltable plastic. Is the pulp material cork, and has the backing layer a thickness of about 2 mm, the particle size must not exceed 2 mm and should preferably are less than 1.5 mm. Since you put the thin decorative layer on this base during the production of the plate or the sheet attaches and the layers are pressed at such a temperature that the plastic hardens / melts, the Plastic compound with the cork filling rise up in the existing openings and depressions in the decorative layer and fill this in, giving the decorative layer a smooth surface and a flawless appearance. The filler material the desired hue can be given, for example a hue which is closer or less to the dominant hue adjoins or stands out from the decorative layer.

The wear layer, which normally consists of a

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Pre-painted 0.5 mm film made of plasticized PVC is applied to the decorative layer before this is combined with the base layer, i.e. all three layers are applied in one and the same operation connected with each other. During the pressing process, the wear layer is also melted so that it becomes the decorative layer adheres well. The wear layer can also consist of a covering material other than a film, for example Plastisol, various paints, polyurethane, etc.

After the product has been pressed for a predetermined time, it is transferred to a cold press, in which it is cooled and at the same time subjected to a higher pressure, expediently about twice as high as in the hot press. The plate or sheet taken out from the cold press has the above, advantageous appearance and a completely smooth wear surface and can be used as such as floor and wall covering.

In order to create a plate or sheet with a relief, a natural material is required, which is a so-called "elastic Memory ". One such substance is cork. The cork with its special cell system is compressed by pressing, but partially springs back with a time delay when it is relieved. Because in the above case the load is only removed after the plastic has cooled down, the state of tension in the cork is blocked, which is why the Plate or web receives the smooth wear layer side. But if the plate or track has cooled down a free heating (i.e. a heating in which it is not influenced by the press plate or the like.) to a If the temperature is higher than the softening temperature of the plastic, the stress state relaxes of the cork, and the cork will return to the shape it was in before it was pressed. One uses plasticized PVC, a reheating temperature of 70-150 C is suitable. After reheating, leave the plate or web also cool freely. This change of state

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leads to a profiled wear layer side of a very advantageous appearance, since the profiling of the The wear layer is controlled by the material of the decorative layer, which means that the pattern and relief are perfectly synchronized will.

As indicated above, cork has proven to be extremely advantageous for the production of a natural material panel with relief, the decorative appearance of the structure and composition of the used, thin Layer or the veneer is dependent. The layer is made into thin sheets by splitting a block of cork conglomerate produced a number of different growth zones with varying, mutual orientation and compressibility exhibit. The different zones have different elasticity and recovery capacity, which means the formation of relief can vary from simple nodules to a completed work of art of nature. Although The cork is currently the most suitable material, other pulps are also conceivable that this for the relief formation have the required elastic memory or to whom this memory can be imparted.

A particular advantage of the method according to the invention is that no pulp is lost as all rejects are turned into granules. Of course, this means further cost savings beyond those that can be achieved by that it is not necessary to fill the decorative layer, and that the quantities of unusable products are low will.

A plate produced in this way with a base layer of granulated cellulose in one Die made of meltable plastic, a thin decorative layer on the base layer and a wear layer a plastic film made of fusible plastic, the latter by being carried out after hot pressing Cold pressing a smooth top or, by re-heating in the free state after cold pressing, one

Has a relief surface is not only extremely decorative, but also extremely advantageous in use, since it is wear-resistant and thanks to its elasticity and insulating ability feels extremely pleasant when walking. The invention is explained in more detail on the basis of the following exemplary embodiment.

On a calendered, 2 mm thick underlayer
plasticized PVC and granulated cork with a particle size of up to about 1.5 mm became a 1 mm thick
Lö cork veneer attached, to which a 0.5 mm thick wear layer made of plasticized PVC was applied. The material was placed in a die provided with spacer rulers with paper bearing a release agent on both sides. The pressing was done in a hot press (180 C)

2
under successively increasing pressure of up to 2 kp / cm

carried out for 5 min. The form and its content

was then put into a cold press while warm.

2 2

brings where the pressing pressure from 2 kp / cm to 5 kp / cm

was increased over 5 min, after which the cold product
was demolded. The product was now completely flat, but was formed on subsequent heating to 130 ° C. for 2 minutes
A relief on the surface, the appearance of which was determined by the structure of the cork veneer used.

Claims (6)

/ f PATENT CLAIMS | 1. \ Process for the production of decorative panels, ν J characterized by the fact that a cellulose, in particular cork, is granulated, after which the granules mixed with -meltable plastic and from the mixture a mat is made that pulp of the same or Another type is cut into thin slices, which in the present state with through openings and depressions be attached to the mat thus produced that on the thin pulp slices a film made of fusible plastic is attached, and that the laminate thus obtained is melted with the supply of heat the plastics and the pressing of the mat material is pressed into the openings and depressions of the panes, after which the pressed plate is cooled. 2. The method according to claim 1, characterized in that the cooling is carried out in a cold press in which the plate is subjected to a higher pressing pressure than with hot pressing. 3. The method according to claim 1 or 2, characterized marked that the plate after the Cooling is exposed to free heating and cooling for the purpose of relief formation of the plastic film. 4. The method according to any one of claims 1-3, characterized in that at least the thin Natural material layer consists of cork. 5. The method according to any one of claims 1-3, characterized in that at least the granulated Natural material consists of wood. 6. The method according to any one of the preceding claims, characterized in that the plastics are plasticized PVC.