EP1279471A2 - Wooden floor and and method for the production thereof - Google Patents

Abstract

Wooden flooring comprises a thick top layer (1), a bottom layer (2) and an intermediate layer (3) which are bound together with a joint-filling adhesive. The surfaces of the top and bottom layer which are glued are unplaned.

Description

The invention relates to a wooden floor according to the preamble of claim 1 and aims to produce a solid wooden floor, which is largely stable against dimensional changes due to swelling and shrinkage, temperature and moisture changes.

Another object of the invention relates to a method for producing the wooden floor.

The properties of the wood are characterized by the fact that it shrinks when it releases moisture and swells when it absorbs moisture. These dimensional changes bring about a change in shape in conventional solid wood products. This creates gaps or faults in the flooring between the individual elements.

Wooden floors have become known in the form of solid wood floors, parquet floors or three-layer floors. Solid wood floors consist of long and short boards with tongue and groove, which are planed continuously on the top and at least striped by the planing knife on the underside.

Parquets consist of parquet sticks, which are parquet timbers, which are provided with a groove on one long side and a broad side and each with a planed tongue on the opposite side. The construction of multi-layer parquet wood consists of a top layer of any type of wood and at least one base layer, which is either made of plywood or by means of a strip mat.

The structure of a three-layer floor consists of a top layer, a middle layer and an underlayer, whereby the middle layer and the underlayer can usually be made of inferior wood than the top layer. The middle class plays the main role in this product. You must wear the top and bottom layer, as well as tongue and groove. In most cases it is also the thickest layer in this type of floor. This process produces three individual layers, which are glued together and then planed and ground to a floor product with considerable losses in yield.

CH 89 917 A has made known a parquet consisting of a plurality of panels arranged one above the other, the panels being connected by water-insoluble adhesive and the top panel being made of hardwood, while the panel underneath lying panels can be made of softwood.

All known multi-layer floors are expensive to manufacture or have not achieved the dimensional stability desired for solid wood floors.

The object of the present invention is to provide a wooden floor in which, while avoiding the disadvantages of the known floors, significantly lower production costs are achieved with almost the same technical properties compared to conventional three-layer floor products. This object is achieved by the measure according to the characterizing part of patent claim 1.

A joint filling material is a special plastic, which is mentioned in the publication "Society of American Foresters" from December 1998, its properties being described in the publication "Eurodicautom, Document 4".

The applicant has surprisingly recognized that the use of this plastic for gluing wood floor layers, in particular when processing rough, preferably rough sawn materials, avoids or reduces the occurrence of yield losses.

A joint-filling glue, which is preferably temperature and water resistant, allows unprocessed (roughly sawn) top and middle layers to be glued and connected to each other to form floor elements with low yield losses and low quality losses or quality improvements, and voids in the wood, such as cracks or holes, can be filled ,

Here, the middle layer can consist of several layers, which can also be connected to one another with the adhesive according to the invention.

Another object of the invention is a process for the production of the multilayer product, which consists in that a polyurethane adhesive is used as the adhesive, which after the processing enables a pollutant-free, waterproof and joint-filling adhesive bond.

According to a further feature of the invention, the wood composite material is produced using native, i.e. natural, carrier materials.

According to a further feature of the invention, the top layer and the bottom layer have an unprocessed surface facing the middle layer or the adhesive layer.

An unprocessed surface is to be understood as meaning, for example, a roughly sawn or not planed or ground surface.

The method steps according to the invention save work steps, such as equalization of the outer layers and the middle layer, compared to known working methods. A simplification of the production processes is also achieved.

By using polyurethane adhesives, critical wood areas such as Knots, cracks, etc., before machining, e.g. by planing, milling, sawing or the like, fixed or filled in cavities, thereby avoiding loss of quality and thereby improving the quality.

Depending on the desired degree of dimensional stabilization or the economic comparability with alternative competitive products, different types of middle layers, e.g. Wood veneers, flax fabrics, hemp fabrics, other fabrics etc. can be used.

In order to prevent or reduce possible moisture absorption or moisture release and thus a change in dimension, the surface can be coated with waxes and / or oils on both the top and bottom of the board.

Further features of the invention are explained in more detail with reference to the drawing.

• Fig. 1 einen Querschnitt der Rohware; Fig. 2 einen Querschnitt der gespalteten Rohware;
• Fig. 3 einen Querschnitt des Produktes mit einer gestürzten Verleimung nach Einkleben der Sperrschicht; und
• Fig. 4 einen Querschnitt des fertigen Produktes mit den abgehobelten Teilen.

Show it:

• 1 shows a cross section of the raw material. 2 shows a cross section of the split raw material;
• 3 shows a cross section of the product with a fallen glue after the barrier layer has been glued in; and
• Fig. 4 shows a cross section of the finished product with the planed parts.

The raw material according to FIG. 1 is made of a solid wood, which is split into a top layer 1 and a bottom layer 2 by splitting, as indicated in FIG. 2. The top and bottom layers 1, 2 are formed in the same types of wood and have the same thickness. The lower layer 2 forms the so-called counter-pull in order to prevent or reduce bowls. "Envelope" means the shape change that occurs, for example results in moisture absorption or release of the wood. If different layers of a sandwich product are connected to one another, which have a different shape change behavior when the moisture changes, then one layer swells or shrinks more or less than another layer. This larger expansion of the lower layer, for example, would result in a bowl compared to the upper layer, so that the hollow side of this bowl would be at the top.

The raw material can be split using a saw or a special knife.

The cover layer 1 forms the visible side of the floor element. The thickness of this layer is also referred to as the wear layer thickness and lies e.g. B. between 3 and 5 mm, but can also have other dimensions.

In a further step, as shown in FIG. 3, a barrier layer 3 is glued in between top layer 1 and bottom layer 2. The intended, glued gluing is an additional measure to stabilize or increase the dimensional stability. A fallen glue is to be understood in such a way that the layers of wood are inserted mirror-inverted on the side facing the wood core. In Fig. 3 the course of the annual rings 4 is indicated in a fallen glue. If, for example, the side facing the wood core is at the top in the top layer 1, it must be directed downwards in the bottom layer 2. Different raw materials, e.g. Glass fiber mats, flax mats, linen mats, wood veneer or the like can be used.

The layers can be glued, for example, in such a way that the adhesive is applied to the mutually facing surfaces of the top and bottom layers 1 and 2, after which the compression with the barrier layer 3 takes place.

However, it would also be possible for the barrier layer or middle layer 3 to be provided with adhesive on the top and bottom, but not the top and bottom layers.

Of course, any other variant is possible.

The adhesive, if it is made of polyurethane, reacts with the moisture, for example with the atmospheric moisture, the residual moisture in the wood or an introduced moisture, for example in the form of water vapor or spray mist. There is a foaming process whereby the foam cracks or knotholes and fills. Synthetic resin dispersion adhesive and synthetic resin solvent adhesive can be used as the adhesive. A one-component polyurethane adhesive has proven particularly advantageous. After the covering layer 1 has been placed with the interposition of the barrier layer 3 and the glue application, the intermediate product thus obtained is placed in a press and pressed with a predetermined pressing pressure. The desired profile according to FIG. 4 is obtained from the product produced in this way by planing, tongue and groove 5 and 6 being produced by milling on the longitudinal and end faces, after which the surface is ground and possibly treated with oil and / or wax.

Of course, various design changes can be made within the scope of the invention. So there is the possibility to use several middle or barrier layers. 3 is only to be understood as an exemplary embodiment. There is also the possibility of providing a different combination of the arrangement of the annual rings as required.

Claims (3)

Wood flooring, consisting of at least three superimposed and interconnected wood layers, at least one middle layer, barrier layer or the like being provided between a solid top layer and a bottom layer, which is bonded to the top and bottom layers by adhesive bonding, which is preferably temperature and is water-resistant, is connected, characterized in that the bond is filling the joint and the cover layer (1) and the lower layer (3) are facing a preferably unprocessed surface of the middle layer or the adhesive layer. A process for producing the multilayer product according to claim 1, characterized in that a polyurethane adhesive is used as the adhesive. A method according to claim 2, characterized in that the production of the wood composite material is carried out with native carrier materials.

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