Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27M—WORKING OF WOOD NOT PROVIDED FOR IN SUBCLASSES B27B - B27L; MANUFACTURE OF SPECIFIC WOODEN ARTICLES
  • B27M1/00—Working of wood not provided for in subclasses B27B - B27L, e.g. by stretching
  • B27M1/02—Working of wood not provided for in subclasses B27B - B27L, e.g. by stretching by compressing

Definitions

• the invention relates to a method for compacting a surface of a wooden workpiece and an apparatus for performing the method.
• wooden workpiece is not only meant for solid workpieces made of wood, such as e.g. Spruce, fir, oak are produced, limited.
• the method described below and the associated device are equally applicable to all materials that are wood-like in terms of material technology, e.g. bamboo, reeds and other wood-based materials, such as plywood, particle board and / or wood-containing or resin-enriched paper, can be used insofar as those components of the wood which are necessary for the production of the thermoplastic adhesive composition are present at least in the area subject to the process according to the invention are.
• the invention has for its object to provide a method and an apparatus for performing the method with which a compacted surface of a wooden workpiece can be produced, wherein a particularly high density of the surface can be achieved, without the addition of foreign materials or chemical substances.
• This object is achieved in a method of the type described at the outset in that the surface of the wooden workpiece - while avoiding the entry of oxygen - by supplying energy to the surface, which inputs a frictional relative movement on the wooden workpiece and thus heating the same, under pressure until the formation of thermoplastic adhesive mass originating from the wooden workpiece is heated in at least partial areas, whereupon the surface and a volume area below the surface is compressed while cooling the same while exerting pressure.
• This process is characterized by the fact that no foreign materials or chemical substances have to be added before, during or after the process; rather, only the wooden workpiece is specifically modified in order to ensure that the areas of a wooden workpiece or several wooden workpieces subject to the described method are abrasion-resistant and to achieve a shock-resistant surface that is much harder than the untreated wood.
• connections of wooden workpieces can be roughly divided into two groups (see also WO 00/97137; integral joining).
• the first group consists in that the transmission of the forces between the wooden workpieces is accomplished by an element which transmits the forces and which is glued to the surfaces of the wooden workpieces to be connected, for example.
• the material or positive connection thus produced is limited to the contact surfaces of the wooden workpieces. Those Workpiece areas that are outside the contact area have no influence on the mechanical properties of the connection.
• connections belonging to this group are generally more resilient.
• Another object of the invention is to provide a method and an apparatus for carrying out the method with which a connection of two wooden workpieces according to the second group described above can be carried out, the addition of foreign materials or chemical substances being avoided.
• This object of the invention is achieved in that both the contact surface of a first wooden workpiece and the contact surface of a second wooden workpiece - while avoiding the entry of oxygen - by supplying energy to the contact surfaces, which supply of energy involves a rubbing relative movement between the wooden workpieces and thus Heating and especially by this heating and by the rubbing relative movement causes destruction of the cell structure, under pressure until the formation of thermoplastic adhesive is heated in at least partial areas of the surfaces in contact with one another, the two wooden workpieces being pressed against one another by pressure with their contact surfaces , whereupon the contact surfaces of the two wooden workpieces and volume areas below these surfaces are cooled, a surface area of at least one of the wooden workpieces is compressed under pressure and with the penetration of ther moplastic adhesive under the contact surface of the compacted wooden workpiece (s), the wooden workpiece is welded.
• the adhesive is obtained from the wooden workpieces to be joined by a targeted supply of energy.
• the wooden workpieces are compacted in and around the area of the joint surface, so that the strength of the joints produced in this way is significantly increased by the material properties of those parts in the joint area and the partial areas located inside the wooden workpieces. It is therefore a "press-weld connection" of the two wooden workpieces.
• the wooden workpiece or the wooden workpieces are preferably conditioned to a predetermined maximum moisture content and / or to a predetermined minimum temperature and / or surface condition, such as roughness, during the energy supply, or the wooden workpiece or the wooden workpieces can be conditioned to a predetermined maximum moisture content, a predetermined minimum temperature and / or surface condition before the energy supply.
• a preferred method variant is characterized in that the friction is generated by an oscillating relative movement between the surface of the wooden workpiece and the surface of a counter workpiece, in particular in the form of a linearly oscillating relative movement (movement device approximately parallel to the surface) or in the form of an ultrasound movement (direction of movement in any angle, preferably at right angles to the surface of the wooden workpiece), the relative movement advantageously being effected with the aid of ultrasound.
• a connection according to the invention is to be created between two wooden workpieces, a second wooden workpiece is used as the counter workpiece.
• the invention described here also has the task of producing a compacted surface of a wooden workpiece, in particular one that is particularly stable with regard to abrasion and impact resistance, with the counter workpiece being a counter workpiece with a higher melting and boiling temperature than the wooden workpiece and with a smooth one Surface with a low, non-sticking wetting angle, such as a metallic or mirrored surface, is used.
• the natural material wood is characterized by its material properties which vary within the workpiece and which, like common woodworking methods, influence the process and the wood connection created in different ways.
• the method presented here also has the task of adapting the method of compacting discussed here and the devices for this to the varying material properties of the natural material wood.
• the degree of compaction according to the invention is thus possible to carry out as a function of properties of the wood workpiece (s), in particular as a function of density, and thus of the varying To prevent material properties of wood-related discontinuities in the areas subject to the process.
• the compacting can also expediently be carried out as a function of a mechanical strength value of the wooden workpiece (s).
• the method is first carried out over a partial surface of a wooden workpiece and then over further partial surfaces of the wooden workpiece, the method being carried out continuously progressively over the surface of a wooden workpiece in accordance with a particularly favorable time-saving variant.
• the compression is expediently carried out by a force approximately perpendicular to the longitudinal axis of the wood fibers of a wood workpiece, preferably in the radial direction of the trunk.
• the compacted surface or the welded joint of the wooden workpiece (s) is advantageously steamed to stabilize the dimension of the compaction according to the invention.
• thermoplastic adhesive is preferably produced in an anaerobic atmosphere.
• a device for carrying out the method according to the invention is characterized by: a workpiece holder for at least one wooden workpiece, a first station with an energy introduction device that can be directed against a surface of the wooden workpiece, a second station with a compression device that can be directed against a surface of the wooden workpiece, and a third station with a cooling device for the wooden workpiece.
• Either a conveying device for conveying a wooden workpiece from station to station or a conveying device for conveying the individual stations to a wooden workpiece can be provided.
• the compression device is expediently coupled to the cooling device.
• the energy introduction device and / or the compression device and / or the cooling device can preferably be brought into direct contact with the surface of the wooden workpiece.
• the workpiece holder is advantageously provided with a conditioning device, such as a drying device and / or heating device, for the wooden workpiece.
• a conditioning device such as a drying device and / or heating device
• the device is characterized in that the energy introduction device is designed as a device acting on a counterpart workpiece, which generates a rubbing relative movement between the counterpart workpiece and a wooden workpiece, advantageously the rubbing relative movement either parallel to the surface of a wooden workpiece to be treated or vertically is directed to this.
• the device For the production of a particularly abrasion and impact resistant surface on a wooden workpiece, the device is characterized in that the counter workpiece has a smooth surface, such as a metallic or mirrored surface, with which it can be brought into direct contact with the surface of the wooden workpiece.
• a smooth surface such as a metallic or mirrored surface
• the counter workpiece is also expediently designed as a wooden workpiece and both wooden workpieces can be brought into direct contact with their contact surfaces to be connected.
• a further station with an evaporation device for steaming a compacted wooden workpiece is advantageously provided.
• the device has a testing device for the non-destructive testing of a wooden workpiece, intervention can be made during and / or immediately after the compression of a wooden workpiece described here if the desired parameters deviate, for example to ensure efficient series production.
• the device is provided with a housing, at least in the area of the energy introduction device and preferably also in the area of the compression device, which is connected to a gas supply line, preferably to an anaerobic gas supply device.
• the device is characterized in that the conveyor device has two conveyor belt systems, the conveyor belts of which are arranged opposite one another in such a way that at least one wooden workpiece of the opposing strands of the conveyor belts runs in one and the same direction and at one and the same speed can be driven, can be inserted, which wooden workpiece can be brought by means of the opposing dreams to the energy introduction device and further to the compression device and cooling device as well as to a possibly provided test device and possibly existing vapor deposition device, with one of the two conveyor belt systems expediently arranged in two in the running direction and into the same Has drivable conveyor belts, between which a feed for another wooden workpiece and / or an energy input device is provided.
• FIG. 1 showing a section through a wooden workpiece transverse to the fiber direction in the undensified state and FIG. 2 in the state compressed according to the invention.
• 3 illustrates the method according to the invention in diagram form.
• 4 and 5 show computed tomography images of compacted surfaces of wooden workpieces.
• 6 to 11 illustrate schematic representations of devices for carrying out the method according to the invention.
• FIG. 1 Using a comparison of FIG. 1 with FIG. 2, which enlarges a wooden workpiece 1 cut under the microscope transversely to the grain direction of the wood on one and the same scale illustrate, it can be seen how the cross sections of the cells 2 are changed by compression. 2, the cells 2 are compressed and it can also be seen that a thermoplastic adhesive 3, which is formed by the wooden workpiece 1 itself, has penetrated between the compressed cells 2. At the lower left corner of the figure, a collection of thermoplastic adhesive 3 can be seen, as it forms, for example, when producing a weldment according to the invention with a second wooden workpiece.
• the general quality of the compression of the wood-based material can be inferred from the extent of the loss of thickness during the sub-processes III to IV, in which the thermoplastic adhesive or the cells are compressed.
• the device shown in Fig. 6 is used to produce a welded connection of two superimposed wooden workpieces 1, 1 '.
• the device has a workpiece holder 4 for two stacked wooden workpieces 1, 1 ', a station 5 for conditioning the two stacked wooden workpieces 1, 1', further in the conveying direction 6 of the wooden workpieces 1, 1 ', a station with an energy introduction device 7, subsequently a station with a compression device 8, which is coupled to a further station, which is designed as a cooling device 9.
• a conveyor device 10 For conveying the wooden workpieces 1, 1 ', a conveyor device 10 is provided, formed by two conveyor belt systems 11, 12, the conveyor belts 13 of which are arranged opposite one another in such a way that the two wooden workpieces 1, 1' rest on the mutually opposite runs 14 of the conveyor belts 13.
• the individual stations, as described above, are located between the back and forth runs of a conveyor belt 13.
• a clamping device a holder by means of negative pressure and / or a surface with high roughness may have to be provided, so that the introduction of energy into the contact surface 17 or connecting joint 18 in the form of vibrations in any desired, preferably 0 ° or 90 ° angle is guaranteed.
• the gap 15 between the two runs 14 of the conveyor belts 13 is advantageously designed to taper, ie the two in the same direction
• Running and opposite dreams 14 of the conveyor belts 13 are not exactly parallel to each other but aligned with each other to form a wedge-shaped gap 15.
• the upper of the two conveyor belt systems 12 is formed by two conveyor belts 13 and 16 arranged one behind the other in the running direction and drivable in the same direction, between which the energy introduction device 7, which in this case is in direct contact with the surface 17 of a Wooden workpiece 1 can be brought, is provided.
• This type of device serves to compact the surface 17 of an individual wooden workpiece 1 in order to form a particularly wear-resistant and impact-resistant surface on this wooden workpiece 1.
• the wooden workpieces 1 and 1 ' are heated by a targeted supply of energy on the surfaces subjected to the method and / or in areas of the wooden workpiece 1, 1' while exerting a mechanical pressure by introducing energy.
• energy is generated, for example, by a relative movement, preferably in the form of a linear circular movement (direction of movement parallel to the connecting joint 18 of the wooden workpieces 1, 1' ) or ultrasonic vibration (direction of movement in any, preferably right-angled, angle to the connecting joint 18 of the wooden workpieces 1, 1 ') between wooden workpieces.
• the relative movement of the wooden workpieces must take place under a force directed at right angles to the connecting joint, so that a constant contact between the wooden workpieces 1, 1 'is ensured.
• a wooden workpiece 1 is moved relative to a non-porous, for example metallic counter-workpiece 19 which has a higher melting and boiling temperature than the melting temperature of the Components of the wood-based material, which components have to be liquefied to form the thermoplastic adhesive 3.
• the surface of the counter workpiece 19 must also have a high wetting angle, so that there is no non-positive connection between the thermoplastic adhesive 3 formed in the subsequent process steps and the counter workpiece 19 can.
• a metal of type 1.43012R according to DIN EN 10088, for example, has the requirements; it is a "Teflon-like steel".
• the introduction of the required energy by, for example, a linearly oscillating relative movement is also suitable for finishing surfaces 17 according to the invention in a continuous process, but also for connecting two wooden workpieces 1, 1 '.
• the progressive heating of the surface of a wooden workpiece 1, 1 '(at least) in the area of the relatively moving contact surfaces between two wooden workpieces 1, 1' or between a wooden workpiece 1 and a counter workpiece 19 has several effects.
• the introduction of energy causes material preparation and conditioning.
• the material wood is conditioned at least in the areas relevant to the subsequent (sub) processes so that the subsequent processes described below can take place.
• the condition of the surface of the wooden workpiece 1, 1 '(roughness, type of processing, etc.) and the physical condition (temperature, humidity, etc.) before the treatment have no effect on the subsequent compression of the wooden workpiece 1, 1'.
• the method according to the invention does not exclude that such preparation and conditioning of the material can be created by pretreatment in a conditioning device and / or by measures external to the process.
• thermoplastic adhesive 3 is formed.
• this thermoplastic adhesive 3 is Prevent access to oxygen to prevent combustion or charring of the wood-based materials.
• the air seal is on the one hand due to the perpendicular to the contact surface (connecting joint 18 or surface 17) mechanical pressure, on the other hand guaranteed by the wood material abrasion and the wood material softening caused by the energy supply.
• the heating of the wood material also leads to an opening of the membranes 20 connecting the wood cells 2, so that the thermoplastic adhesive 3 penetrates the contact surface under low pressure and can be pressed into the wood material interior. (see Fig. 2).
• thermoplastic adhesive 3 can also take place in an anaerobic atmosphere to prevent combustion and / or carbonization of the wood material, for which purpose the device is provided with a housing 21 into which an anaerobic gas Feed device 22 opens (see the illustration in FIG. 8).
• thermoplastic adhesive 3 formed in this way consists largely of lignin and / or its chemical modifications; the viscous, adhesive properties of the thermoplastic adhesive 3 thus obtained from the material wood is used for the compression of the porous material according to the invention described below. Due to the constant destruction of the cell structure on the surface of the material to be compressed, lignin from volume areas that were below the surface at the beginning of the process can also be used to produce the thermoplastic adhesive.
• thermoplastic adhesive After sufficient formation of the thermoplastic adhesive and heating of the wood material, further energy input is prevented; the wood material is compacted according to the invention.
• the softened cells 2 are compressed by plastic deformation under high pressure. Because of the wood structure and, above all, because of the progressive softening of the cell structure caused by the progressive heating of the wood material, no compression or only an unavoidable deformation of the wood workpiece 1 or 1 'due to the compression of the cell cavities occurs in the compression due to the energy input 7 softened areas transverse to the direction of the applied force.
• thermoplastic adhesive 3 hardens.
• the cooling process can be accelerated by external measures.
• thermoplastic adhesive In the event that the formation of the thermoplastic adhesive takes place between two wooden workpieces 1, 1 ', the adhesive properties and simultaneous compression of the wooden workpieces 1, 1' according to the invention occur at least on their surfaces, i.e. Impregnation by means of the thermoplastic mass and compression of the cells, for a positive connection of the wooden workpieces 1, 1 '.
• the natural material wood is characterized by its properties which vary within the wooden workpiece 1, 1 ', which can be seen with the naked eye, for example, by means of the early and late annual rings.
• the weakest parts of the wooden workpiece 1, 1 ' influence its use, such as in connection with other wooden workpieces.
• the quality control described below offers the possibility of checking the formation of the thermoplastic adhesive 3, the compression by impregnation of the cells 2 by means of the adhesive 3 and a compression of the cells 2 without destruction.
• thermoplastic adhesive 3 formed according to the invention as well as the compressed cell structure have a higher specific density than untreated wood.
• the resulting changed physical properties of the modified areas of the wood make it possible to draw conclusions about, for example, the degree of compaction and / or the amount of the thermoplastic adhesive composition formed.
• Common methods for non-destructive quality control such as ultrasound and computed tomography, can be used to control the quality of the compression produced according to the invention during and / or after the process.
• 4 and 5 show computed tomography images of compacted surfaces of two wooden workpieces 1, 1 'welded together. On the one hand, the densified areas on the surfaces of the wooden workpieces are clearly recognizable due to the light color. 5 contains the representation of the measuring points of the local density relative to the ambient air.
• Line A marks the approximate course of the welded joint, i.e. the joint 18;
• Line B the annual ring position (late wood).
• the described quality control is suitable in addition to a - -
• the physical properties of the compressed wood workpieces 1, 1 ' are clearly dependent on the amount of thermoplastic adhesive 3 formed and - the extent and dimensional stability of the wood structure being compacted.
• FIG. 3 shows the essential steps of the method according to the invention in diagram form, the change in thickness of a wooden workpiece 1 being shown over time.
• the reduction in thickness is plotted on the ordinate; the abscissa serves as the time axis.
• the negative area of the time axis is characterized by the energy supply, the positive area by the suppression of the further energy supply.
• the subdivision of the overall process or approximation of the graph shown in FIG. 3 into partial processes discussed below is based on the subjective perception during the process and the change in the graph shown in FIG. 3.
• the transition between sub-processes of the method according to the invention is generally smooth, the sub-processes being designated I to V below.
• FIG. 8 illustrates a surface treatment of a large-sized wooden workpiece 1, the surface 17 of which is compressed.
• the device used for this purpose is installed with its stations in a housing 21 which is connected to a gas supply device 22. Anaerobic gas is preferably supplied.
• Fig. 9 shows a device without a housing with which smaller wooden workpieces 1 can be treated in a continuous process according to the invention, i.e. can be provided with a compressed surface 17.
• FIG. 10 shows a variant according to which three wooden workpieces 1, 1 ', 1 "can be welded to one another, first a conveyor belt 13 welding two superimposed wooden workpieces 1, 1' to one another and subsequently a third wooden workpiece 1" to the two previously welded wooden workpieces 1, 1 'is applied and is welded to the previously welded two wooden workpieces 1, 1' by means of a further device, which also has a conveyor belt 16 as a means of conveyance.
• the energy introduction device 7 is accommodated in each case in a deflection roller 23 for the conveyor belt 13 or 16, so that here there is no direct contact of the energy introduction device 7 with the wooden workpiece 1, 1 '. The energy is thus transferred via the conveyor belt 13 or 16 to the wooden workpieces 1, 1 ', 1 ".
• the invention is not limited to the exemplary embodiments shown in the drawing, but can be modified in various ways.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mechanical Engineering (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Chemical And Physical Treatments For Wood And The Like (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)
• Adhesives Or Adhesive Processes (AREA)

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• 2004
  • 2004-02-04 AT AT0016104A patent/AT503091A2/de not_active Application Discontinuation
• 2005
  • 2005-02-04 WO PCT/AT2005/000034 patent/WO2005075165A1/fr active IP Right Grant
  • 2005-02-04 AT AT05706178T patent/ATE409557T1/de not_active IP Right Cessation
  • 2005-02-04 EP EP05706178A patent/EP1711320B1/fr not_active Revoked
  • 2005-02-04 US US10/597,662 patent/US7896992B2/en not_active Expired - Fee Related
  • 2005-02-04 DE DE502005005528T patent/DE502005005528D1/de active Active

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