EP1616680A1 - Method for manufacturing wooden elements having a grain imitating the natural wood grain - Google Patents

Abstract

Several thin rectangular layers of veneer (1) are sandwiched and then stuck together under pressure between top (2) and bottom (3) dies of a press to form curved die-cast parts (4), which are laid on one another and pressed together in such a way as to separate the wooden parts in layers. The die-cast parts are curved in both lengthwise and cross-wise directions of the veneer layers, so that these layers form a three-dimensional, waved upper surface and the wooden parts, to achieve a grained finish, are separated form the die-cast part.

Description

The invention relates to a method for the production of wood elements with a natural wood grain replica drawing, wherein a plurality of thin rectangular peeled veneer layers are stacked and bonded under pressure between the male and gegengleicher die of a press to coincident curved Teilpreßlingen, which then superimposed form-fitting and with the interposition of binder pressed to the compact, after which the wood elements are separated from the compact layer by layer.

Such processes, according to which veneer layers are first combined to give compacts and these subsequently to compacts, are known from US Pat. No. 4,388,133 A1, US Pat. No. 4,465,539 A and GB 1 391 077 A. In order to obtain an artificial drawing, the veneer sheets are pressed into U-shaped compacts in which the fibrillation of the individual veneer lamellae run parallel to each other, after which the wood elements are separated in layers at an acute angle to the grain longitudinal direction of the compact. With such methods, however, only flat wooden elements with parabolic, but not elliptical drawings can be produced. Planks with a natural, flat-like design can not be made in this way.

According to another known method (CH 423 196 A) first veneer sheets are peeled off on a peeling machine of wood blocks, after which the wood block to facilitate the peeling process was previously heat treated with steam or hot water. The artificial wood elements are then cut from Holzpreßlingen, which consist of the interposition of adhesive stacked together and pressed together veneer sheets. To achieve an artificial drawing, the veneer sheets are pressed into U- and / or V-shaped blocks, in which the fibrillation of the individual veneer lamellae run parallel to each other. Of these blocks, artificial wood elements are cut on a rotary cutting machine, which, however, have no uniform design and size.

A similar process is known, for example, from US Pat. No. 3,418,195 A, in which a compact of veneer sheets glued together is shaped in a U-shaped or V-shaped manner between a male mold and a die of a press, in both the longitudinal and transverse directions After curing of the glue in the block longitudinal direction veneer sheets are peeled off. If rare precious woods are to be simulated, it is possible to simulate special pore areas and annual rings when veneering the veneer sheets between these thin aggregate veneer layers, which consist of veneer sheets pressed together and glued together in parallel, optionally other colors, whose fiber direction is in the stacking direction, ie transverse to the fiber direction the adjacent veneer sheets, is aligned (DE 3 148 577 A). A major disadvantage of the known method is that, especially in the area of the gates, a significant loss of material occurs and that the veneer sheets pressed wood blocks with increasing block thickness do not have a consistently uniform drawing, so that in particular when using thicker wood blocks from which flat wood elements are to be cut off , no similar drawing of all of the same compact cut wood elements can be guaranteed.

The invention is therefore an object of the invention to provide a method of the type described above, with the most simple way artificial wood elements can be made as natural as possible, similar and predeterminable fladerartiger drawing.

The invention solves this problem in that the Teilpreßlinge be arched between the male and female both longitudinally and transversely of the rotary veneer layers, wherein the peelable veneer layers are deformed with respect to a median plane on both sides undulating Teilpreßlingen with a three-dimensional wavy surface structure, and that the Wooden elements in order to achieve a flat-like drawing parallel to the central planes are separated in layers from the compact.

The compact is not manufactured in one step, but it is first Teilpreßlinge of several peeled veneer layers pressed with respect to a median plane to both sides, ie perpendicular to the median plane, running, three-dimensional wave structure, whereby the Teilpreßlingen of the die and patrix a surface with three-dimensional valleys and hill structure is imprinted. Subsequently, several similar Teilpreßlinge superimposed form-fitting and pressed with the interposition of binder in the press to the compact, wherein the Teilpreßlingen and the compact of the mold is always impressed the same three-dimensional wavy surface structure. Since the peeled veneer layers are pressed first to relatively thin, over its cross section almost continuously uniformly deformed Teilpreßlingen with wavy surface structure and only then to the cuboid compact with wavy surface structure, are cut off from the then plane wood elements parallel to the center planes, can be with the invention according to the Cutting off the wood elements, in particular board elements, are guaranteed by the compact a consistently uniform natural fladerartige drawing for all wood elements. This makes it possible to create a product that meets the highest requirements in terms of surface design or in terms of the drawing picture. The respective drawing motifs can be chosen almost freely, since to achieve a certain desired similar drawing of the wood elements only one adapted to the desired shape pressing tool with varied wavy surface structure must be used. Special Advantages of the invention are not only in the uniformity of the drawing picture, but also in the fact that the compressed wood barely warped after curing and swells and turns, which is why it is particularly well suited for use in parquet or wall panels or Deckenvertäfelungen. An inventive wooden element can thus be used without hesitation in rooms with climatic fluctuations in conjunction with floor heating as a parquet. By gluing the individual peeled veneer layers also results in a high abrasion resistance, whereby a long life of the wood elements is ensured.

Rotary cut veneers, which are peeled off endlessly from a tree trunk, are glued, for example, in such a way that, after being pressed, they have a drawing oriented in the longitudinal direction of the board. When peeling microcracks are od by the compression molding with interim release of the binder, such as glue. Like., Stabilized and compensated. Likewise, hardness and compressive strength as well as the wear resistance of the wood elements according to the invention increase over solid wood elements. Due to the more irregular pores compared to solid wood sawing veneers, wood elements produced by a process according to the invention also have a greater thermal resistance to solid wood.

If the drawing is to be expressed even more strongly, it is advisable to color the binder prior to application to the peeled veneer layers or Teilpreßlinge for the purpose of simulating annual rings with a different color to the peel veneers. The method according to the invention thus provides the possibility of reproducibly producing wood motifs in a simple manner, the wood elements also having improved mechanical properties compared to natural wood.

A particularly uniform continuous drawing for all wood elements can be achieved when the peeled veneer layers are pressed with a thickness of 1 to 4mm to Teilpreßlingen with a thickness of 10 to 60mm, in particular from 30-40mm, and from the three to, for example ten compacts joined compact wooden elements are sawn in a thickness of 2 to 10mm.

If as little as possible waste, so waste wood incurred in the production process according to the invention, it is advisable to superimpose the remaining after the separation of the plane-parallel wood elements remaining portions of the compact with their curved surfaces with the interposition of a binder form-fitting and to press into a cuboid compact, from which subsequently further wood elements are separated. This ensures that the gates can be recycled and must not be disposed of.

Due to the particularly good mechanical and thermal properties of the wood elements produced, it is particularly advantageous to connect the wood elements with carrier material, in particular of wood, to parquet elements that meet the highest standards.

To best connect the individual Teilpreßlinge or gates, ie in particular without air inclusions, or to be able to press together, it is advisable to glue the Teilpreßlinge under a deformation of an intermediate layer of at least one rotary veneer layer and to press, or the remaining sections of the compact below a deformation of an intermediate layer of at least one peel veneer layer to glue and to press. This can be compensated if necessary in Teilpreßlingen or gates existing differences in the form of binder and veneer.

If a parquet is to be created with a predefined drawing, which in the usual way has applied to a base body and walkable cover layer, the top layer of wood should meet the highest thermal and mechanical requirements, it is recommended if the top layer manufactured by a process according to the invention and on the base body applied wood element

Fig. 1 und 2

zwei nach einem erfindungsgemäßen Verfahren mit verschiedenen Preßwerkzeugen hergestellte Holzelemente,

Fig. 3 bis 6

Verfahrensschritte zum Herstellen eines Materialblocks,

Fig. 7

einen fertigen Materialblock im Querschnitt und

Fig. 8

eine Matrize in Schrägansicht.

In the drawing, the invention is illustrated schematically with reference to an embodiment. Show it:

Fig. 1 and 2

two wood elements produced by a method according to the invention with different pressing tools,

Fig. 3 to 6

Method steps for producing a material block,

Fig. 7

a finished block of material in cross section and

Fig. 8

a die in an oblique view.

In a method for the production of wood elements with a natural wood grain replica drawing a plurality of thin rotary veneer layers 1 is stacked with the interposition of a binder and compressed between male and female mold 3 3 of a press, not shown to Teilpreßlingen 4 desired shape. In order to ensure the most uniform possible drawing for the elements to be produced, the peeled veneer layers are first pressed with intermediate of the binder between the male part 2 and die 3 to Teilpreßlingen 4 approximately constant thickness with both longitudinally and transversely wavy peeling veneer layers 1 (Fig. 3 and 4).

As a result, the rotary veneer layers 1 and the partial pressed bodies 4 of the male part 2 and die 3 are impressed with a three-dimensional wave-shaped surface structure in the form of valleys and hills, as can be seen in particular from FIGS. 3 and 4.

Subsequently, after at least partial curing of the binder, three Teilpreßlinge 4 between the same male 2 and the same die 3 with the interposition of binder, and optionally at least one rotary veneer layer 1, pressed into a cuboid compact 5 with the same three-dimensional wavy surface structure (Fig and Fig. 6), of which after curing of the binder plane wood elements 6 with a flat-like drawing parallel to the center planes (Fig. 7) are cut in layers from the compact in Preßlinglängsrichtung and the required strength. The resulting fladerartige drawing can be seen in particular Figs. 1 and 2, which appears after the cutting of the wood elements 6 from the compact 5 as height layer lines of the three-dimensional valleys and hill-shaped surface structure. The desired drawing is specified by the male or female form. Examples of this can be found in FIGS. 1 and 2. 3 and 4 show the pressing tool in cross section at the points assigned to the wood element 6 according to section III-III and IV-IV of FIG. 1st

In order to continue to use the gates 7, 8, the two on one side both in the longitudinal and transverse direction wavy and on the opposite side plan gates of the compact with the interposition of a binder at the mutually complementary wave-shaped surfaces to a compact fifth pressed (Fig. 7), from which in turn wood elements 6 are cut in the required strength. In this case, it is particularly recommended that the gates 7, 8 of the material block with the interposition of a binder and two rotary veneer layers 9 on the mutually complementary undulating surfaces to a further compact 5 to be pressed.

If a top layer for a parquet with the thickness of 2 to 10 mm is to be created with the method according to the invention, it is recommended that peeling wood veneers 1 having a thickness of 1 to 3 mm and a length of 1300 to 2500 mm and a width of 150 to 250 mm to be pressed into cuboid Teilpreßlingen 4 with a thickness of about 30 mm between the die 3 and male part 2. In order to obtain a broader layer position, for example, six pre-pressed Teilpreßlinge 4 of the same shape are pressed together, whereby a compact 5 is formed with a thickness of about 180-200mm. Since the peeled veneer layers are slightly displaced relative to each other during pressing, it may be necessary to plan the obtained compact prior to sawing on its side surfaces in order to obtain a flat compact.

Claims (8)

A method for the production of wood elements with a natural wood grain replicating drawing, wherein a plurality of thin rectangular peeling veneer layers are stacked and bonded under pressure between male and gegengleicher die of a press to coincidentally curved Teilpreßlingen, which are then superimposed positively and pressed with the interposition of binder to the compact according to which the wood elements are separated from the compact layer by layer, characterized in that the Teilpreßlinge are arched between the male and female both longitudinally and transversely of the rotary veneer layers, wherein the peelable veneer layers are deformed into Teilpreßlingen having a wavy surface structure, and that the wood elements for the purpose Achieving a fladerartigen drawing parallel to the center planes are separated in layers from the compact. A method according to claim 1, characterized in that the peeled veneer layers are pressed with a thickness of 1 to 4mm to Teilpreßlingen having a thickness of 10 to 60mm, in particular of 30-40mm, and that of the three-ten Teilpreßungen joined compact wooden elements in one Thickness of 2 to 10mm are sawn off. A method according to claim 1 or 2, characterized in that the remaining after the separation of the plane-parallel wood elements remaining portions of the compact with their curved surfaces with the interposition of a binder form-fitting superimposed and pressed into a cuboid compact, are subsequently separated from the further wooden elements with flat-like drawings , Method according to one of claims 1 to 3, characterized in that the binder is colored prior to application to the rotary veneer layers or on the Teilpreßlinge with respect to the peelable veneer layers different color. Method according to one of claims 1 to 4, characterized in that the wood elements are connected to carrier material, in particular of wood, to parquet elements. Method according to one of claims 1 to 5, characterized in that the Teilpreßlinge are glued and pressed under a deformation of an intermediate layer of at least one undeformed rotary veneer layer. A method according to claim 3, characterized in that the remaining portions of the compact are glued and pressed under a deformation of an intermediate layer of at least one undeformed rotary veneer layer. Parquet with an applied to a base body, walkable cover layer, characterized in that the cover layer is a manufactured according to a method according to one of claims 1 to 8 and applied to the base body wooden element.

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