WO1996001377A1

WO1996001377A1 - Method of joining together parts consisting at least partly of wood or wood-like materials

Info

Publication number: WO1996001377A1
Application number: PCT/EP1995/002527
Authority: WO
Inventors: Marcel Aeschlimann; Heinrich Koester; Laurant Torriani; Elmar Mock; Peter Perler
Original assignee: Createc Patent Holding S.A.
Priority date: 1994-07-01
Filing date: 1995-06-29
Publication date: 1996-01-18
Also published as: CH692091A5; AU2978695A

Abstract

In the method proposed, parts (A, B) consisting at least partly of wood or wood-like materials are joined together by placing at least one layer of thermoplastic (L) between the surface regions to be joined and these regions are excited mechanically, e.g. by ultrasonic waves. The at least one layer of thermoplastic may for instance be a coloured or colourless paint layer (L) which carries out the function of a sealable coating in the regions of the surface to be joined and a protective and/or colouring function in other regions of the surface. Suitable for use with the method proposed are prior art paints with a thermoplastic component, e.g. acrylic paints. Friction welding or orbital welding can be used instead of ultrasonic sealing.

Description

METHOD FOR ASSEMBLING PARTS THAT

AT LEAST PART OF WOOD OR WOOD-LIKE MATERIALS

The invention is in the field of wood processing technology and relates to a method according to the preamble of the first independent patent claim for joining parts which at least partially consist of wood or wood-like materials.

Parts made of wood or wood-like materials (made of wood-based materials), such as plywood or chipboard, are joined together according to the prior art either by mechanical connecting means such as screws or nails, or they are glued, with an adhesive usually being applied to both surfaces to be joined is brought and the two surfaces are then pressed together during a drying or hardening time depending on the type of adhesive. In the same or similar manner, parts made of wood or wood-like materials are also connected to parts made of plastic.

If the objects to be manufactured by assembling the above-mentioned parts are to be painted, that is to say with a colorless paint or a paint -? ,

are treated, depending on the joining technique and the varnish used, the following difficulties arise: when screwing or nailing, injury to a previously applied coloring or varnish layer can hardly be prevented; Layers of lacquer on surfaces to be joined by gluing can have a negative effect on the adhesive properties of the adhesive; Adhesive pressed out of connection points can negatively influence the adhesive properties of subsequently applied paints and varnishes or discolor varnishes or paints applied before gluing. Even on parts joined together by gluing, which are not painted, only small amounts of adhesive emerging from the connections are unsightly and undesirable and are difficult to prevent. If the parts are painted after they have been joined, the joints are without paint, that is to say unprotected and therefore have a limited service life.

It is the object of the invention to provide a method for joining parts, wherein the parts consist at least in part of wood or wood-like materials, which method is an improvement with respect to the disadvantages described above. The method according to the invention should be simple and applicable regardless of whether or not the parts to be joined are coated with protective and / or colored lacquer before or after the joining.

This object is achieved by the method as defined in the patent claims.

The method essentially consists in connecting two parts to be connected, at least one of which is made of wood or of a wood-like one

Material consists of at least one layer that is at least partially made of one thermoplastic material to bring and then connect the two parts by mechanical excitation. The mechanical excitation is preferably effected by ultrasonic waves (ultrasonic welding), at least one of the parts to be connected or its surface to be connected being excited to vibrate at an ultrasonic frequency. For this purpose, at least one of the parts to be joined is held under welding pressure at least in the area of the connection to be created between an ultrasonically excitable surface (working surface of a sonotrode) and an anvil and subjected to ultrasound waves, the ultrasound waves connecting perpendicularly, parallel or obliquely to the ¬ can reproduce the surfaces. After a short welding time and preferably a short holding time, the parts are connected to one another via the thermoplastic layer.

Instead of ultrasound welding, friction welding or orbital welding can also be used, the surfaces to be connected being moved essentially parallel to one another (in a straight line or cyclically).

The at least one thermoplastic layer to be introduced between the parts to be connected can be a layer of a protective and / or colored lacquer applied to the wooden part or to the wooden parts, which layer consists of a thermoplastic or has at least thermoplastic constituents and its known per se The function is to protect the wooden surface, for example, against the weather and / or to give this surface a certain color. In this case, the first step of the method according to the invention is that, for example by brushing, spraying, dipping, rolling or pouring, a liquid lacquer is applied to the wood surface, which lacquer is then attached to the surface. send dries or hardens. The application and letting it dry can be repeated and, for example, first a primer can be applied and then the actual paint. The coating can be limited to surface areas to be joined, but advantageously extends over further areas belonging to the surface of the finished object which is assembled from the parts or over entire parts to be joined together. In a second step, the surfaces to be joined, of which only one or both of them have a lacquer layer (advantageously dry or hardened), are brought onto one another and welded by means of ultrasound. According to this process variant, for example, two wooden parts (at least one of them painted) or a painted wooden part with an unpainted plastic part made of a thermosetting plastic can be connected to one another.

It is also possible to carry out the welding before the lacquer layer applied last is completely dry or hardened. In such a case, it turns out that the drying or hardening is even accelerated by the welding.

The at least one thermoplastic layer to be introduced between the parts to be connected can also be introduced in the form of a thermoplastic film between the surface areas to be connected. According to this variant of the method, for example, two wooden parts (lacquered or not lacquered) can be connected to one another or a wood part (lacquered or not) with a part made of a thermoset.

Another variant of the method according to the invention consists in that with the wooden part (lacquered or not lacquered) a part made of a thermoplastic Most or from a material is connected to at least one thermoplastic component, the surface layer of the thermoplastic part facing the wooden part serving as a thermoplastic layer.

The method according to the invention is described in more detail with reference to the following figures. Show:

FIGS. 1 to 3 show three exemplary variants of the method according to the invention;

FIG. 4 shows the tensile strength of various connections produced by the method according to the invention;

FIG. 5 shows a diagram to illustrate the influence of welding parameters on the tensile strength of a connection produced by the method according to the invention;

FIGS. 6 to 8 different uses of the method variants according to FIGS. 1 and 2;

FIGS. 9 to 11 different applications of the method according to FIG. 3;

FIG. 12 shows a surface which is equipped with energy direction sensors and is to be connected according to the method according to the invention.

FIG. 1 shows an example in the form of a schematic arrangement

Variant of the method according to the invention, in which two wooden parts A and B, both of which are lacquered (lacquer layer L), are connected to one another. A known ultrasonic welding system is used for welding used. On the one hand, this has a surface 1 that can be excited with ultrasound (working surface of a sonotrode 4) and a stable anvil surface 2, parts A and B to be connected, which, for example (as shown) are covered on all sides by the lacquer layer L, are welded P between sonotrode work surface 1 and anvil surface 2 are held. In order to prevent lateral displacement of the parts A and B to be joined, lateral holding means (indicated by arrows S in the figure) are usually also necessary.

The ultrasonic welding system has the following parts (not shown in FIG. 1) for generating and transmitting the ultrasonic energy: a generator for generating electromagnetic waves with a frequency usually in the range from approximately 18 kHz to 140 kHz (for example 20 or 40 kHz) , a converter which converts the electromagnetic waves into mechanical waves and is usually a connection of several piezoelectric elements, and a resonance part (often in two parts: booster and sonotrode 4), by means of which the generated mechanical waves are optionally transformed in amplitude are transferred to the one of the parts to be welded (A) by mechanical coupling via the aforementioned excitable surface 1 (working surface of the sonotrode 4).

The mechanical waves generated by the converter are transmitted with as little loss as possible by carefully coordinating the materials and shapes of the converter, booster and sonotrode, so that these parts vibrate in resonance and standing waves (with stationary nodes) arise. The conditions that the ultrasonic welding of lacquered wooden parts (process variant according to FIG. 1) places on the parts to be joined and on the lacquer are as follows:

- The lacquer must have at least one thermoplastic component in its dry or hardened state, which is the case for many commercially available synthetic lacquers (colorless or colored), both water-soluble and solvent-soluble.

- The surfaces of the parts to be joined must be parallel within relatively narrow limits, whereby wooden surfaces with a roughness that is normal for surfaces to be painted (for example planed or milled) can be processed without problems. Furthermore, the surfaces to be joined must have a very short welding time (order of magnitude: one second) and possibly also a short holding time

(Order of magnitude a few seconds) can be pressed against each other and guided.

The advantages of the variant of the method according to the invention according to FIG. 1, for example compared to a glued connection, are as follows:

The method according to the invention can be used for any directions of the wooden surfaces to be connected relative to the wood grain, i.e. in particular brain-brain, brain-side or side-side connections are possible, but also connecting surfaces that are skewed to align the grain.

For two functions, only a single substance (lacquer) has to be applied to the surfaces of the wooden parts: the lacquer assumes a protective and / or coloring function on surfaces of the finished object the surfaces of the parts to be joined have the function of a connecting means (comparable to the function of an adhesive) in the form of a weldable coating.

The production of an object assembled and painted from parts is accelerated since the separate application of an adhesive and a drying or hardening time for the adhesive are eliminated for the assembly. The necessary welding times (including holding time) are very short (a few seconds).

The production of multi-colored objects is facilitated by coloring parts with subsequent assembly.

Instead of entire objects, individual parts can be painted, which can result in a reduction in the size of the necessary equipment, especially in the case of larger objects and dip or tunnel painting processes.

On objects with several joints, these can be welded one after the other without significantly increasing the time required for the assembly, so that the necessary clamping devices can become simpler and smaller.

Storage times of any length can be switched on between painting and welding.

Experiments with parts made of beech and spruce wood (see also Figure 4), which were carried out with acrylic-based paints, show that in paints with conventional layer thicknesses in the range of 0.1 mm, ultrasonic welding creates connections with tensile strengths in the range up to approx. 10th N / mm ² , which corresponds to the strength of connections between wooden parts made with conventional adhesives required by the DIN standards and exceeds the tensile strength of European softwoods, for example.

In the same way as shown in FIG. 1, lacquered wooden parts with unpainted wooden parts or lacquered wooden parts with thermoset parts can also be connected. Advantageous applications of the method variant according to FIG. 1 are, for example, the joining together of painted parts to form window frames, picture frames or other frames or the application of parquet strips to support plates made of a wood-like material. Another application is also the application of final thermoset strips or lacquered or unpainted wooden slats on the front sides of lacquered chipboard. Details of further applications of the method variant according to FIG. 1 are shown in FIGS. 6 to 8.

FIG. 2 shows the same schematic arrangement as FIG. 1, a second, exemplary variant of the method according to the invention. Here again two wooden parts C and D are connected to one another, a thermoplastic layer, for example in the form of a thermoplastic film 5, being positioned between the two parts. Suitable thermoplastic films are, for example, commercially available films made from copolymers of polyamide or from polymethyl methacrylate (PMMA), which have a thickness of, for example, 30 to 200 μm. It is also conceivable to bring the thermoplastic layer 5 not as a film but in the form of powder between the surfaces to be connected, the powder being held on one of the surfaces to be connected, for example by a thin, still moist lacquer layer. The execution of the welding step for the method variant according to FIG. 2 is the same as described in connection with FIG. 1; the parts of the welding device shown in FIG. 2 are designated with the same reference numbers.

In the same way as shown in FIG. 2, that is to say with a thermoplastic layer in the form of a film or a powder layer, which is introduced specifically for the connection between the surfaces to be connected, lacquered wooden parts can also be lacquered with one another, lacquered with unpainted wooden parts or lacquered or unpainted wooden parts are connected with thermoset parts.

Application examples for the process variant, as shown in FIG. 2, are again window frames and other frames. The application examples described in connection with FIGS. 6 to 8 can be carried out both according to the method variant according to FIG. 1 and according to the method variant according to FIG.

Figure 3 shows the same schematic arrangement as Figure 1, a third exemplary variant of the inventive method. Here, a wooden part E and a thermoplastic part F are connected to one another, the surface layer of the thermoplastic part serving as a thermoplastic layer in the area of the connection.

The method variant according to FIG. 3 is suitable for connecting painted or unpainted wooden parts with parts made of, for example, polymethyl methacrylate (PMMA), acrylic butadiene styrene (ABS), polyvinyl chloride (PVC), polyethylene (PE) or styrene acrylic nitrate (SAN).

Examples of application for the method variant according to FIG. 3 are, for example, the application of final thermoplastic strips on the faces of chipboard or the connection of painted or unpainted wooden parts by means of dowels made of a thermoplastic material, as described in more detail in connection with FIGS. 9 to 11 shall be.

FIGS. 4 and 5 show results of tensile shear tests which were carried out with previously painted wooden parts connected according to the method according to the invention in accordance with the test specification DIN EN 204 (production of the samples in accordance with DIN 205). On the one hand, a varnish from Intex was used, which was applied in two layers as a primer (type tlmf, acrylic-alcyd combination) and topcoat (type DSL, acrylic) with a total layer thickness of approx. 90 μm (dry). On the other hand, a white lacquer from the same company was used, which was applied in three layers as a primer (type: ISO, acrylic), acrylic pre-lacquer (type: AVO) and window finish lacquer (type: FSL, acrylic) with a total layer thickness of approx. 150μm.

An ultrasonic welding system from Branson (type 921) was used to carry out the tests. Flat surfaces of approx. 400 mm ² each, welded parallel to the sonotrode work surface, were welded. The welding parameters were: frequency 20 kHz; maximum power 2000 W; Amplitude (on the working surface of the sonotrode): approx. 60μm; Welding times between 0.2 and 1 second; Holding time approx. 5 sec and welding pressure (force for pressing the parts together per unit area of the surfaces to be connected) up to 300 kPa.

Figure 4 shows the tensile strength σ in N / mm ² (according to DIN EN 204) as the mean and 95% - confidence interval for the following samples:

Sample of wood top coat Application type welding surface time [s] a beech planed glaze brush 0.6 b beech planed glaze brush 0.9 c beech planed glaze rack 0.9 d spruce planed glaze rack 0.6 e beech planed glaze * Brush 0.6 f spruce planed glaze * brush 0.6 o σ beech milled glaze brush 0.6 h spruce milled glaze brush 0.6

* without primer

The parameters of an ultrasonic welding are in particular the frequency of the generated ultrasonic waves, the amplitude with which the working surface of the sonotrode or the surface to be welded of the part excited by the sonotrode vibrates, the power consumed by the system, the welding pressure P and the welding time.

Frequency and maximum power of the ultrasound are usually specified by the ultrasound system. The amplitude of the vibrating working surface of the sonotrode depends on the amplitude of the converter and the choice of booster and sonotrode. Welding pressure, amplitude and absorbed power are linked in the system in such a way that the welding pressure is limited for a certain amplitude and a certain maximum power (the smaller the amplitude, the higher the possible) Welding pressure) that with constant welding pressure and higher amplitude more power is consumed and that with constant amplitude and higher welding pressure more power is consumed.

Since the method according to the invention mostly involves so-called far-field welding (welding of surfaces that are more than approx. 1 cm away from the working surface of the sonotrode), welding with relatively large amplitudes is recommended.

The welding energy required for a specific weld is determined, among other things, by the type of paint to be welded and the geometry of the parts to be welded (energy losses in the part material). In the case of a welding performance that is primarily provided by the system, the welding energy is controlled over the welding time.

Theoretically, optimally energy-efficient welding would be expected if the first part to be welded (A, FIG. 1) were mechanically completely coupled to the sonotrode, resonated with it, and were configured in this way (arrangement of nodes in this part ) that its surface to be welded would vibrate with an amplitude suitable for the welding. Furthermore, the two surfaces to be welded should be mechanically coupled as little as possible so that the waves propagate as little as possible into the second part (B, FIG. 1) and into the anvil. As soon as the thermoplastic layer (eg varnish) between the two parts to be connected softens, the mechanical coupling between the parts to be connected is eliminated. Ultrasonic welding tests carried out with an arrangement according to FIG. 1 show that - despite the same pressure conditions on the contact surfaces between the sonotrode and the lacquered wood or between the anvil and lacquered wood as on the surfaces to be joined - good weld connections are produced without any the contact surfaces with the sonotrode or with the anvil change the painted surface, so they do not stick to the sonotrode or the anvil after welding. In other words, the coupling between the sonotrode and the part to be welded is sufficiently large, that between the surfaces to be connected is sufficiently small. This is especially true when using very smooth sonotrode and anvil surfaces. If these are rough or uneven, appropriate impressions can occur in the layers of lacquer that lie on these surfaces during welding.

The welding parameters must be determined experimentally for each specific application.

FIG. 5 shows, as an example of such an optimization, the tensile stress σ [N / mm ² ] of the connections produced as a function of the parameters welding time t [s] and welding pressure P [kPa]. These are connections of planed beech parts and coated with the glaze mentioned. The figure shows that the highest tensile stresses are achieved at low welding pressures and high welding times.

FIGS. 6 to 8 show applications of the method variant according to FIG. 1 or FIG. 2 in which the surfaces to be welded do not run parallel to the sonotrode work surface 1 and the anvil surface 2 as in FIGS. 1 and 2. The layers of paint or thermoplastic films between the connecting parts are not shown. Lacquer layers, as explained in connection with FIG. 1, extend at least in the areas of the surfaces of parts A and B to be connected by ultrasound welding. Identical parts are identified by the same reference numbers as in FIG. 1.

FIG. 6 shows a welded connection 6 to be created, oriented obliquely to the sonotrode work surface 1, which can also be produced using the method according to the invention, the sonotrode work surface 1 advantageously, as shown, approximately the size of the projection of the welded connection having. Lateral holding means (arrows S) are particularly important for such applications.

FIG. 7 shows an application in which the function of lateral holding means is at least partially taken over by the shape of the welded connection 6. It is a welded joint to be created, composed of differently aligned welding surfaces, as is often used in wood technology. Such a welded joint can also be created using the method according to the invention, the sonotrode work surface 1 again, as shown, advantageously having approximately the size of the projection of the welded joint.

FIG. 8 finally shows a weld connection 6 to be created, which runs perpendicular to the sonotrode work surface 1 and to the anvil surface 2. Such a welded joint can also be carried out with the method according to the invention. In this case, the lateral holding means (arrows S) take over part of the function of the welding pressure P. For this application, the sonotrode work surface 1 is narrow and, as in the other applications described, only stimulates one (A) of the two parts to be connected.

It is also possible. To use anvil surfaces that are not parallel to the sonotrode work surface and / or non-flat sonotrode work surfaces or anvil surfaces.

FIGS. 9 to 11 show, as an example application of the method variant according to FIG. 3, the connection of painted or unpainted wooden parts with the aid of plastic dowels. These dowels consist of a plastic material with at least one thermoplastic component. The dowel is conical and its cross-section is at least regionally larger than the cross-section of the bore into which it is inserted. The dowel is positioned in the bore and pressed into the bore by pressure and ultrasound, the shape of the dowel being adapted to the shape of the bore and, analogously to the process variant according to FIG. 3, the dowel surface with the wooden surface in the bore is connected.

FIG. 9 shows the principle of the dowel method using an exemplary application. Figures 10 and 11 show corresponding designs of dowels and corresponding holes.

FIG. 9 shows how, for example, two wooden parts G and H (lacquered or not lacquered), each of which has a conical blind bore 7, can be connected to the dowel and thus to one another using a plastic dowel 8 using the method according to the invention. The cross section of the dowel 8 is at least regionally so larger than the cross section of the bores 7 that the dowel cannot be completely inserted into the bores. The dowel is pressed into the hole by the action of a welding pressure P and ultrasonic waves until the two wooden parts lie on top of each other. If the wooden parts are lacquered, the lacquer layers are also welded to one another at the points of contact, which leads to a further connection (according to FIG. 6) of the two parts.

In an analogous manner, as shown in FIG. 9, of course, not only wooden parts with wooden parts but also plastic parts or parts coated with plastic can be connected to wooden parts, the necessary dowels being formed, for example, on the parts to be connected to the wooden parts. One application of such a method is, for example, the fastening of fittings to wooden parts.

Figures 10 and 11 show exemplary dowels 8.1 and 8.2 and corresponding blind holes 7.1 and 7.2. In FIG. 10, both the dowel 8.1 and the bore 7.1 show steps 9, in which the diameter of the dowel or bore tapers towards the end of the dowel or bore. In FIG. 10, the bore 7.2 is continuously conical and only the dowel 8.2 shows steps 9.

Exemplary dimensions for dowels and bores, as shown in FIGS. 9 to 11, are for example as follows: Bore: depth 24mm, maximum diameter 8mm, minimum diameter 5.5mm, five steps with a taper of 0.5mm, dowels : maximum diameter 8mm, minimum diameter 6mm, four steps, each with a taper of 0.5mm, whereby the step height corresponds approximately to the step height in the hole. The dowel and the bore can also have more or fewer steps, for example the bore can have one step and the dowel none, the dowel diameter corresponding to the larger diameter of the bore.

It can be seen that with a connection as described in connection with FIGS. 9 to 11, the thermoplastic material of the dowel penetrates up to 50 mm into the wood, which results in very strong local connections that exceed the strength of the wood. It also shows that the dowel material penetrates into the wood, particularly in the area of the dowel tip and in particular parallel to the wood fibers. If, for example, a dowel is welded into a blind hole made perpendicular to the side surface of a wooden part (perpendicular to the direction of the fibers), the dowel material penetrates into the wood, particularly in the area of the end of the blind hole and particularly transversely to the blind hole, as a result of which the anchor is properly anchored. The form of such anchoring that can be achieved obviously also depends in particular on the design of the dowel tip.

For the connection of surfaces according to the method according to the invention, it can be advantageous to equip the thermoplastic layer with energy direction sensors, as is known from the ultrasonic welding processes of plastic parts. This is particularly advantageous if the surfaces to be welded are very smooth. In the variant of the method according to FIG. 3 (welding of the wooden part and the thermoplastic part), energy direction sensors can be used to ensure that the thermoplastic part is only heated and plasticized on its surface to be connected to the wooden part. Energy direction transmitters are essentially points or lines protruding from the surfaces to be connected and are places where the plasticization begins under the influence of ultrasound.

Energy direction transmitters can be applied to lacquer layers by means of screen printing dots or introduced into film material (process variant according to FIG. 2) by appropriate structuring. It turns out that specially applied energy direction transmitters are usually not necessary when connecting lacquered wooden parts because the lacquer layer, due to its own structure and due to the roughness of the lacquered wood surface, has sufficient unevenness that can take over the function of the energy direction transmitter .

FIG. 12 also shows schematically (section through the parts 10 and 11 to be connected before the connection and after the connection) the attachment of an end strip 10 made of a thermoplastic on an end face of a fiberboard 11, the surface of the end strip which is connected to the chip - Plate is to be connected, has energy directors in the form of longitudinal increases.

Claims

PATENT CLAIMS

1. A method for joining parts which at least partly consist of wood or wood-like materials, characterized in that between the surfaces to be joined by two parts (A / B, C / D, E / F) at least one thermoplastic layer (L, 5) it is positioned that the parts and the at least one thermoplastic layer are held against one another and that at least one of the two parts is then mechanically excited in the sense of welding the at least one thermoplastic layer.

2. The method according to claim 1, characterized in that the mechanical excitation is an excitation with ultrasonic waves.

3. The method according to claim 1 or 2, characterized in that the surfaces to be joined together of the parts are pressed against one another during the mechanical excitation.

4. The method according to claim 3, characterized in that the parts continue to be pressed together during a holding time after termination of the mechanical excitation.

5. The method according to any one of claims 1 to 4, characterized in that the at least one thermoplastic layer (L) on wood or wood-like material applied layer of a protective and / or colored lacquer, which lacquer has at least one thermoplastic component.

6. The method according to claim 5, characterized in that the lacquer has an acrylic base.

7. The method according to any one of claims 1 to 4, characterized in that the at least one thermoplastic layer (5) is a film or powder layer made of a thermoplastic or of a material with at least one thermoplastic component which is introduced between the parts to be joined together.

A method according to claim 7, characterized in that the film or powder layer consists of a copolymer of polyamide or of polymethyl methacrylate (PMMA).

9. The method according to any one of claims 1 to 4, characterized in that the at least one thermoplastic layer is a surface layer of a part to be joined (F) made of a thermoplastic or of a material with at least one thermoplastic component.

10. The method according to claim 9, characterized in that the thermoplastic is polymethyl methacrylate (PMMA), acrylic butadiene styrene (ABS), polyvinyl chloride (PVC), polyethylene (PE) or styrene acrylic nitrate (SAN).

11. The method according to any one of claims 9 or 10, characterized in that the part to be joined from a thermoplastic or a

Material with at least one thermoplastic component is a dowel

(8) and that the other part to be joined is a wooden part with a hole (7) which essentially corresponds to the dowel (8).

12. The method according to claim 11, characterized in that the dowel

(8.1, 8.2) has a gradually tapering cross-section, that the bore (7.1, 7.2) also tapers gradually or continuously towards the inside and that the smallest bore cross-section is smaller than the smallest dowel cross-section.

13. The method according to any one of claims 2 to 12, characterized in that the parts to be connected are clamped between an essentially flat sonotrode work surface (1) and an anvil surface (2), that the surfaces to be joined are parallel and / or oblique to the sonotrode - Work surface (1) are arranged and that the size of the sonotrode work surface is selected to be essentially the same size as the projection of the surfaces to be joined.

14. The method according to any one of claims 2 to 12, characterized in that the parts to be connected between a substantially flat

Sonotrode work surface (1) and an anvil surface (2) are clamped in such a way that the surfaces to be joined are arranged perpendicular to the sonotrode work surface and that the sonotrode work surface is located on one (A) of the parts (A, B ) is placed directly next to the connection to be created.

15. The method according to any one of claims 2 to 14, characterized in that the excitation is carried out with ultrasonic waves with a frequency of 20 to 40 kHz.

16. The method according to claim 1, characterized in that the mechanical excitation consists of a friction of the surfaces to be connected against each other.

17. The method according to any one of claims 1 to 16, characterized in that the at least one thermoplastic layer has energy direction sensors on at least one of its surfaces.

18. Use of the. Method according to one of claims 1 to 17 for the production of frames from different painted or non-varnished frame parts made of wood.

19. Use of the method according to one of claims 1 to 17 for attaching end strips made of wood, a thermoplastic or a thermoset on the end faces of chipboard.

20. Use of the method according to any one of claims 11 or 12 for fastening fittings made of plastic or plastic-coated materials to wooden parts.

21. Use according to claim 20, characterized in that the dowels are integrally formed on the fittings.