WO2011029904A1

WO2011029904A1 - System for converting wood fibres into a state processed by metering devices, prepared wood fibre material and extrudate produced therefrom

Info

Publication number: WO2011029904A1
Application number: PCT/EP2010/063315
Authority: WO
Inventors: Michael Theurl
Original assignee: Theurl Leimholzbau Gmbh
Priority date: 2009-09-11
Filing date: 2010-09-10
Publication date: 2011-03-17
Also published as: AT508715A1

Abstract

The invention relates to a method for converting wood fibres into a state processed by metering devices. The invention further relates to a wood fibre material that is prepared using said method and to an extrudate produced therefrom in the form of a granulated compound, sections or injection moulded parts. Wood fibres from industrial pulping processes cannot be metered without the length of said fibres being drastically shortened, (said fibres being already short in relation to other natural fibres). By dividing the fibres into small, discrete fibre portions, which can be predetermined in size and characteristics and can thus be metered, by means of a moving tool together with a perforated plate, a metering device can discharge the material thus prepared in a reproducible manner and the structure of the fibres remains largely intact.

Description

System for transferring wood fibers into a condition processable by metering devices, as well as processed

Wood fiber material and extrudate therefrom

This patent application claims the priority of

Austrian Patent Application A 1445/2009, filed on September 11, 2009, the disclosure of which is hereby incorporated by reference into the disclosure of this patent application.

Technical area

The invention relates to a process for the treatment of wood fibers. The invention also relates to a wood fiber material.

The invention further relates to an extrudate.

The invention also relates to a fiber composite product. In addition, the invention relates to an arrangement for

Treatment of wood fibers.

Background of the invention

Although the state of the art already deals with the dosage and the possibly preceding pretreatment of fibrous materials or natural fibers in general, none of the processes or devices mentioned therein offers a suitable one

Possibility to transfer wood fibers into one with

Dosers processable state, the typical

Fiber structure is to be largely preserved and no strong

Shortening of the fiber material is associated with it.

In most cases, the term "wood fibers" - especially in connection with thermoplastic composites - used wrongly, as in Truth ground wood chips are used. So will

For example, in the publication WO 2006/060714 AI repeatedly referred to "cellulosic material ... selected from ... wood fibers" reference, however, it can be seen from the embodiments that "wood flour", ie, ground wood chips ("wood flour") with the typical grain sizes, documented at the mesh sizes "40/60 mesh".

It is namely in the processing of wood chips for

Composite materials, for example, for wood polymer composites (WPC) in the extrusion process, for a desirable process stability and composite quality necessary that the chips are quite uniform

Have grain sizes. For example, the most commonly used wood chip product for WPC is usually in the size range of about 300 - 500 pm (max. The bulk densities for this material are typically between 0.19 to 0.22 g / cm ³ , while coarser chips may also have bulk densities at or below 0.10 g / cm ³ . The typical

The ratio of length to width (aspect ratio or slenderness ratio) for wood shavings is mainly between 1 and 4 (maximum about 6), so these are more of cubic shape. In contrast, wood fibers have a slenderness ratio on average between 20: 1 and 80: 1, but up to 100: 1 can be achieved. Wood fibers are therefore of significantly elongated shape - for example, wood fiber bundles

Dimensions of 20,000: 1,000 pm, while the anatomical wood fiber single cell has a ratio of approximately 5,000: 50 pm. In addition, the occasionally appearing wood fiber powder processing technology under no circumstances with wood or Refinerfasern

be compared.

Furthermore, in the hitherto documented state of the art, although several methods and devices for the controlled release of natural fiber material is discussed, but goes from the claims themselves or the descriptions of the task solution and evt.

Embodiments clearly show that in particular the inventions refer to cut long fibers of flax, hemp, kenaf, jute, ramie or sisal, etc., while wood fibers are not mentioned. Thus, publication WO 2007/137378 A2 discloses a process for the production of a thermoplastic compound from natural fibers and polyamides, which presupposes that the fiber material is previously shortened to processable lengths of 0.1 to 15 mm in a "cutting knive mill" and only then then, after further chemical treatment and drying, fed to an extrusion. In the application CA 2473319 (AI), in turn, flax fibers are used for the production of the thermoplastic composite by extrusion, which must be shortened beforehand "on a standard scutching mill / grinding mill".

Since the cited fibers of caraua and flax, as well as those of all other non - woody plants, in their shape and their properties marked differences from the wood fibers themselves, should in

Further brief on the chemical, biological and

production-technical reasons for this and their consequences for further processing. While terms such as fiber, natural fiber, wood fiber or refiner fiber denote the industrially obtained fiber material, the term fiber cell refers to the anatomical single cell in the original cell structure.

In the first instance, wood cells in the cell wall contain not only polysaccharides, such as cellulose and hemicelluloses, but also lignin, which is completely different from lignin, the actual "lignin or wood pulp," in a much higher proportion than in the others

Fiber plants. Lignin is amorphous and plays a crucial role in compressive strength, but the isolated wood fibers are also more brittle. Furthermore, the fiber cells in the trunk wood are formed by a mantle-cambium active over decades and centuries by cell division in a constantly identical configuration ("secondary

Thickness growth "). These are thus firmly in a comprehensive

Association of equivalent cells involved, with the

elongated fiber cells of the softwoods are very similar and have a length of typically less than 5 mm. In contrast, the remaining fibrous plants are those that only increase in peak growth, while an apparent increase in shoot thickness occurs merely by stretching the existing cells without cell proliferation ("primary growth of thickness"), which also has their short lifespan of only 1 or a few years justified. In such plants usually only the more durable fiber cells are lignified. These are arranged to very long fiber bundles from some hundreds of individual cells and can be easily separated from the rest, not fibrous cell structure. In the case of flax, hemp, kenaf, jute and ramie, for example, the fiber bundles are present in the bast, ie the soft part of the bark, and thus in a peripheral position around the shoot ("bast fibers"), while those of sisal are embedded in tissue of thin-walled, mostly parenchymatous Cells are arranged in the leaf ("leaf fibers").

Lastly, due to the anatomy presented, there is a significant difference between the wood fiber and the remaining natural fibers, significantly in the process of disintegration

Cell structure and in the formations of the fiber products themselves. With the pulping process for fiber plants without secondary

Thick growth can be isolated almost completely in its natural length because of the lighter solution from the plant these long fiber bundles. These natural fibers are thus, depending on the species, traded with average lengths of about 30 - 60 cm and can easily bundled into rovings, turned into threads or ropes or on to Woven or nonwovens interwoven and, if desired, cut open again, so be divided into shorter sections.

The development of Stammholz, on the other hand, requires others

Processes that include mechanical (grinding), thermal (pressure-heat), and chemical digestion steps in a variety of ways. In the context of today almost exclusively industrial

thermo-mechanical refining technology is used, it is first crushed, the wood parts then boiled under steam and pressure and finally fed to a disc refiner, a grinding tool, where the cell structure - unlike the resolution of the other fiber plants - resolved down to the anatomical single fiber without destroying this even to a greater extent. In addition, however, a certain amount of fiber bundles still exist here, which naturally have larger dimensions, albeit far below those described above.

The thus obtained wood pulp, also called TMP (Thermo-mechanical Pulp) or Refinerfasern, therefore, may have a wide range of 1/10 mm to 35 mm or more in terms of the lengths of its fiber components, but the average in the range slightly below the natural Length of the single fiber comes to rest, so for example between 2 mm and 4 mm. A similarly wide spreading normal distribution applies to their diameter. All industrial fibers isolated from the trunk wood of trees thus remain in their length well behind the fiber bundles isolated from the other fiber plants.

A key advantage of wood fiber is its worldwide

Security of supply. According to the FAO, in 2005 the world-wide production of wood fibers alone for pulp and fiber plates amounted to approx. 440 million tons, while the produced quantities of hemp, flat, jute, kenaf and sisal together amounted to only approx. 5 million tons. In addition, stand Wood fibers without the fluctuations in crop yield typical of seasonally grown fiber crops.

Now, in the intellectual property literature, which describes the processing and pretreatment of natural fibers for subsequent

Dosage devices describes, for example, in extrusion plants, on the one hand wood fibers, such as refiner fibers from thermo-mechanical decomposition, not mentioned and thus not taken into account their peculiarities compared to other natural fibers, on the other hand taken for the cited natural fibers no statements on the type of fiber pretreatment, such in the publications CA 2565260 AI or CA 2584888 (AI). However, as stated above, at least in the case of wood fibers, this is necessary.

Because the typical properties of even short wood fibers, to bend, to hook, to ball together etc.

distinguishes these significantly from cut fibers

Fiber plants without secondary growth in thickness. Since the latter, as stated above, come from elongated fiber bundles with lengths of up to 30 or 60 cm, it is almost necessary to shorten the long strands before they are fed to dispensers or similar devices for controlled material delivery, as otherwise with help could not be further processed by stripper, doffer, dowel or dosing rollers. By cutting, in particular by the short cutting, but here material can be obtained with relatively straight fiber sections, whereby a controlled discharge through the discharge of Dosierbehältern or even an automatic trickling and a pneumatic discharge is possible. This is achieved either by suitable cutting machines or, for example, by bale milling, which remove layerwise fiber material from pressed bales. In this context, the patent application AT 504709 AI is not a method in the context of the present application, since the device made known therein for the addition of components to any present in the receptacle wood fibers already used for mixing itself. Here, too, remains unclear in which shape the wood fibers are filled, since it can not be reconstructed how the wood fibers in the receptacle in a "lumpy or

to pass over or be present as such "particulate" form.

In the patent DE 10121034 B4 a device is described with which, inter alia, fiber material with moderate to poor flowability in such a way to be converted into a mass flow, that thus an extruder for the production of

thermoplastic compound can be charged. From the

The descriptive part together with the cited example shows that the operation with already shortened fibers or short cut fibers from plants without secondary growth in thickness - in this case flax with lengths between 1 - 15 mm (average fiber length 6 mm) - was designed. Similar typical lengths for these types of fiber can be found in other publications.

In fact, in the case of wood fibers, for example

Refiner fibers from thermo-mechanical disintegration, not possible, a pretreatment customary for flax or similar long fibers by milling or cutting to approximate flowability

without being an extremely strong one

Shortening compared to the rest of natural fibers anyway already shorter wood fiber material is accompanied, which in fact equals a grinding and separation to the single fiber, whereby the average fiber length of for example 2 - 4 mm would be further reduced. With well-known for some time methods for the development of fiber material in connection with subsequent dosing for the production of thermoplastic compound, the patent DE 102 14 654 B4 is concerned. However, here as well in the course of the described opening and resolution of fiber bales with a bale cutter or with shredder, including the subsequent hammer or

Schneidmühle made no statements about the type of deformation achieved, the concomitant changes in the fiber structure and overall on the state of the fiber material after processing. However, due to the terms "pre-shredded" and "dissolved," it can be appreciated that this method is intended for such fibrous material which after passing through the hammer or

Cutting mill can be approximately transferred into individual fibers and then sucked off. This may, as described above, for short-cut fibers from plants without secondary growth in thickness, such as flax or hemp apply, but would result in wood fibers directly to a reduction to well below the already low mean fiber length of 2 -4 mm. Consequently, it is not surprising that in the exemplary embodiments described below on the one hand experiments with the already mentioned flax fibers, here with 6-8 mm length, on the other hand with synthetic fibers made of PET are mentioned. Overall, the two-stage preparation process with shredder and subsequent hammer or granulator appears complex, uneconomical and is not technically suitable for wood fibers. Furthermore, wood fibers can not be used as loose fibers in the embodiment described

But cut or short cut fibers from plants without secondary growth in thickness are available. Finally, it should be pointed out that the gravimetric dosing devices cited as suitable for fiber dosing are special types for

Fiber material, in particular for short cut fibers from plants without secondary growth in thickness, and therefore can not be compared with the conventional devices in advance of extrusion plants. This means that in addition to extensive and complex process of disintegration of the fiber material also own devices for metering are to be used, whereby the profitability compared to WPC compound from wood flour falls further.

DE 1089540 A discloses a process for obtaining a mat of crosslinked lignocellulosic fibers for the production of

Fibreboard. A fiber separator consists of vibrating screens, a wind sweeper and a spin dryer. The fibers obtained are fed to a housing in which symmetrically arranged openings are formed at the bottom. The diameter of the openings is chosen so that individual threads are pressed against the ground due to generated compressed air to pass through these openings. Below the openings is a sieve belt, on which the fibers form a fleece.

DE 19616892 A1 discloses a process for producing a precursor suitable for the production of wood-based panels. The precursor consists of compacts. The compacts are formed by shortening long fiber raw materials in a Koller extruder by shearing stress on and in extrusion channels. A starting material is conveyed by a grinding belt and crushed on the grinding belt by so-called rumbling. The grinding path has a sieve at the bottom, which forms the pressing channels. It is processed here wood fibers, which come from oil palms or C4 plants.

From the previously documented state of the art to methods or devices which a continuous dosage of

Describe natural fibers is summarized immediately apparent that wood fibers, such as refiner fibers of thermo-mechanical Aufschließ, on the one hand not mentioned and whose peculiarities compared to other natural fibers were not considered,

On the other hand, it can also be deduced from the cited documents that such wood fibers can not be processed with the methods described without greatly altering their configuration and fiber structure.

Presentation of the invention

The object of the present invention is therefore to provide a system for the treatment of wood fibers, so that they are converted into a processable by metering device state, the typical fiber structure is largely retained.

This object is achieved by a method of transfer of

Wood fibers in a state processable by metering devices, by a wood fiber material, by an extrudate, by a

Fiber composite product and by an arrangement for the treatment of wood fibers having the features according to the independent

Claims solved.

According to one embodiment of the invention, there is provided a method of converting wood fibers into a condition processable by metering devices, wherein in the process a coherent wood fiber feedstock is reduced by a moving tool portioning to smaller, discrete and predictable fiber size portions and properties while retaining substantially the fiber structure is divided.

According to another embodiment of the invention, wood fiber material prepared according to one is provided

Method with the features described above. According to yet another embodiment of the invention, there is provided an extrudate made in accordance with a method having the features described above.

According to a further embodiment of the invention, a fiber composite product is produced, produced from a wood fiber material with the features described above or from an extrudate with the features described above.

According to yet another embodiment of the invention, an arrangement for the transfer of wood fibers in a through

Dosing device processable state provided, wherein the arrangement comprises a feeding device for supplying a

related starting material of wood fibers and a

Portioning device having a moving tool, which is arranged to divide the supplied contiguous starting material of wood fibers into smaller, discrete and predeterminable in size and properties fiber portions while largely maintaining the fiber structure.

In particular, the "hardwood" of the stem axes (branches, branches, twigs) of trees can be considered as "wood." Wood can be regarded in particular as a material that

(in particular to a significant extent) stores lignin in the cell wall.

Under a "fiber" may under this application

In particular, a structure can be understood which has a ratio of length to width (aspect ratio or slenderness degree) of greater than 10, in particular greater than 20. Fibers, unlike chips, are therefore elongated structures. Wood fibers can be one

Slimming ratio of on average between 20: 1 and 80: 1, wherein up to 100: 1 or more can be achieved. Wood fiber bundles can show dimensions of 20,000: 1,000 pm, while the anatomical wood fiber single cell has a ratio of approximately 5,000: 50 pm. By a "substantial retention of the fiber structure" can be understood in particular that due to the inventive processing process in the portions of the wood fibers still have a fiber structure, in particular a ratio of length to width (aspect ratio or slenderness) of greater than 10,

in particular greater than 20. If substantially retained, at least 80% by weight, in particular at least 90% by weight, of the wood fibers in the portions should have such aspect ratios. Preferably, at least 90% by weight of the wood fibers in the portions have an aspect ratio greater than 10 and at least 80

In other words, as a result of the treatment according to the invention, the typical fiber structure is retained essentially without shortening and is not ground.

As "thermoplastics" in particular plastics can be considered, which deform with heat and maintain its shape on cooling., Examples of thermoplastics are polypropylene or

Polyethylene. Thermoplastics, also called plastomers, are therefore

Plastics that can easily be deformed within a certain temperature range. This process is reversible, that is, it can be repeated by cooling and reheating.

As "thermosets", also called duromers, especially plastics can be considered that can not be deformed after curing.

A "dosage" is understood to mean, in particular, a controlled supply and delivery which is uniform within controllable limits.

As "mills" are in particular mechanical

Shredders understood by hitting or rubbing. In a hammer mill beating metal rods can be used. In a ball mill can balls with regrind in a drum be used. Double-flow mills can also be used according to the invention.

A "hacker" may be understood to mean a mechanical crusher using a knife or a knife assembly, and a "disc hacker" may include a chipper blade disposed radially on a disc. A "drum chipper" can have a chopping knife, like a planing head, on a cylindrical drum, and knife ring chippers can also be used.

A "granulator" can also be used and has a function like a hacker

Reducer knife and a fixed counter knife crushed.

According to one embodiment of the invention, a method is provided for transferring wood fibers into a state processable with metering devices, whereby the typical fiber structure is largely retained prepared therefrom extrudate in the form of granulated compound, provided by profiles or injection molded parts.

By dividing small, discrete, predeterminable in size and properties and thus metered fiber portions by means of a moving (for example, translational or rotationally moving) tool with perforated plate a dosing device can carry the thus prepared material in a reproducible form, the fiber structure is largely retained.

According to the invention, the long-standing technical problem has been solved, especially fibers made of wood (which, for example, as

can be present) in portions of specifiable properties (for example, in terms of size and / or shape), resulting in a dosable processing of the Portions (for example in an extruder) is important. Wood fibers are due to their good availability, a preferred material, but which is not pourable and therefore conventionally difficult portionable. By a moving knife, the bale can be divided and fed upon reaching a predetermined portion size, for example by means of a perforated plate, a downstream metering device. Since the upstream equipment already defined portions

Provides properties as dosable units, according to the invention, a conventional metering device can be used, which can make their own development dispensable.

Although the state of the art already deals with the metering and the possibly preceding pretreatment of fibrous materials or natural fibers in general, none of the processes or devices mentioned therein offers a suitable one

Possibility to transfer wood fibers into one with

Dosers processable state, the typical

Fiber structure is to be largely preserved and no strong

Shortening of the fiber material is associated with it.

According to the invention, a method is thus provided which is suitable for converting wood fibers, for example refiner fibers from thermomechanical digestion, into a state processable by metering devices, characterized in that a compacted or otherwise contiguous starting material is separated by a portioning device into smaller, discrete, in size and properties are predetermined and thus metered fiber portions is divided and the typical fiber structure is largely retained.

Since, as shown above, in the case of wood fibers, such as refiner fibers from thermo-mechanical decomposition, it is not possible, a usual for flax or similar long fibers pretreatment by milling or cutting to the approximate flowability without being an extremely strong one

Shortening of the wood fiber material goes, the fact of a

Milling and separation equal to the single fiber, whereby the average fiber length of, for example, 2 - 4 mm would be further greatly reduced, it is proposed here, the compacted or otherwise contiguous starting material is divided into smaller, discrete fiber portions such that they of the

Discharge device of a Dosiertrichters, for example, a lfach- screw, can be detected and discharged without problems. In this case, the portioning process can be selected so that fiber portions of uniform shape and size arise.

To achieve reproducible shape and size is the

Specification of a fixed size required. This can be done in a suitable manner by a perforated plate, which is constantly large

Punching holes in a support plate, such as a metal plate, has to be achieved. Through the replacement of the perforated plate, the process can be changed in terms of portion sizes. So can

For example, the openings are chosen between 6 and 16 mm in 2-mm increments, so are always well above the typical average length of wood fibers from refining processes. This perforated plate can in shape and position of the engagement region of an upstream, moving in repetitive steps tool such

be nestled so that the engagement area is limited by a sufficient distance downwards from the perforated plate. The tool now decreases by the movement of an upcoming pressed bale material and brushes it over the perforated plate until it reaches its end

Portions have formed, which fall through the punch holes. The tool can perform, for example, rotational movements, wherein the engagement region forms a circle. In this case, it is possible to form this from cutting blades or with such equip. It may also represent a roll body which is suitably equipped with spikes, pins or combs. The roller can thus z. B. combs, pins, corrugations, spines or the like on the surface. Wood fibers, especially refiner fibers from thermo-mechanical Aufschließungsprozessen be for economic transport in a compacted form in so-called

Pressed bales with about 250 - 300 kg / m ³ , and, for example, with typical dimensions in accordance with pallet dimensions of, for example, 0.7 x 1.1 x 1.2 m (L * W * H) traded. Such a pressed bale or parts thereof can be filled by a suitable conveying device, in particular a conveyor belt, into a filler neck, which is mounted above or in front of the rotating tool.

In contrast to the necessary reduction of long fibers

However, plants without secondary growth in thickness is in the

In this case, the rotating knife tool, such as those of a drum chipper or a granulator, not provided to reduce otherwise unprocessable long fibers, but the compacted or otherwise contiguous starting material of wood fibers should be divided only in metered fiber portions. A possible reduction is only necessary where overlong fiber bundles with lengths far above the described means must be separated in order to achieve the division into fiber portions.

The tool can also carry out translational movements to remove fiber pulp from the upcoming wood fiber material and to make it more suitable for forming, through the perforated plate

transportable fiber portions to edit.

The resulting fiber portions should just be small enough to later a stable, continuous discharge from a metering device, including transfer to a subsequent

To allow processing unit. However, the portioning should not Too small to avoid too much fiber shortening as an undesirable side effect. Experiments have shown that a suitable size band can be selected, for example, by hole openings between 6 and 16 mm.

Such a metering device can, for example, in the

Mixing of the processed according to the above method

Wood fiber material can be used with thermoplastic polymers and / or additives in an extrusion process (in others

Processing processes can also be a thermosetting material used). In this case, the selected size is the

Portioning openings in the perforated plate are also crucial for a stable process and above all the homogeneity of the wood-fiber polymer melt to be achieved. A thermoplastic composite material obtained in this way has several advantages over conventional WPC composites. Since the wood content is not in the form of cubic wood particles (wood flour or

Wood chips) but is fibrous, the material has better mechanical properties in terms of strength and elastic moduli. Furthermore, the wood fibers are derived from industrial processes and can therefore be desired in terms of the desired for the extrusion

Moisture content already dried in the manufacturing process according to customer requirements. On the other hand, wood chips for WPC production, which are usually used as a waste product of the wood industry

Available, laboriously spotted and dried. Overall, the production cost of wood chips for WPC production is considerably higher than that of wood refiner fibers.

Furthermore, the distribution described here of the

Wood fiber in predeterminable fiber portions due to the homogeneity of the material the ability to dose the processed material on simple volumetric metering devices, without the otherwise typical in this dosage in connection with fiber material To have to accept fluctuations in the mass flow. By dividing the wood fiber material into uniform fiber portions, the volumetric discharge can now be kept sufficiently constant so that sufficient homogeneity is guaranteed in the subsequent processes.

Furthermore, gravimetric metering devices can also be used. In this case, a balance or a dosimeter at the bottom of the metering device takes over a constant monitoring of the discharged mass per unit time .DELTA.ηη / Δί to minimize those fluctuations in the dosing, which by the typical properties of

inconsistent grain or material sizes arise.

According to a further exemplary embodiment, the arrangement according to the invention has a metering device for metering a predeterminable amount of the portioned wood fiber material. The portioned wood fiber material is fed to the dosing device after the portioning device.

According to a further exemplary embodiment, the arrangement has a conveying device which is set up to guide and compact the metered and portioned wood fiber material after the metering device. The conveyor may for example have a screw conveyor in single or double version. With conical design and corresponding screw geometry can additionally during the promotion of the metered and portioned

This wood fiber material further conveyed and simultaneously compacted in preparation for the subsequent process steps or

be pressed together.

According to a further exemplary embodiment, the metered portioned wood fiber material can be forwarded after the metering device in a transfer device and, for example, then the conveyor or other devices, such as For example, be fed to an extruder or a mixing device.

According to a further exemplary embodiment, the metered portioned wood fiber material and / or a plastic and / or an additive can be supplied separately from one another to an extrusion process. By means of the extrusion process in the extruder is

For example, the wood fiber material mixed with the further component (plastic, additive) is exposed to a high pressure and a high temperature, so that after the extrusion process

Fiber composite material is available. From the fiber composite material differently shaped fiber composite products can be produced.

According to a further exemplary embodiment, the arrangement has a first mixing device, which is connected directly or indirectly downstream in an exemplary embodiment of the dosing device. The first mixing device may be arranged in exemplary embodiments such that therein

Component mixtures or individual components introduced separately, mixed and in compacted form to the

Extrusion screws are passed.

According to a further exemplary embodiment, the

Arrangement further comprises a second mixing device, which is designed such that the plastic and the additive and optionally the metered and portioned wood fiber material to the

Component mixture are miscible. The second mixing device is arranged within the arrangement such that the

Component mixture from the second mixing device of the first mixing device or directly to the extruder can be fed. This second mixing device may, for example, have a funnel with stirrer and a discharge device, including control of the discharge quantities. According to the exemplary one described above

Embodiments, the metered and portioned wood fibers and the other components, such as the various plastics and / or additives, can be supplied to the extruder in various ways.

a. ) From the second mixing device can first a

homogenized component mixture from the portioned and metered wood fiber material and the metered plastics and / or optionally other additives are produced and the extruder be passed directly or indirectly. There depending on the physical

Characterization of the portioned wood fiber material and the grain sizes of plastic and possibly other additives between the

Bulk density of the component mixture (as determined by the second

Mixing device is discharged) and that material density, which can be well absorbed and processed by the extruder screws, may be greater differences, it has proved to be advantageous if, as a further embodiment, the component mixture after the second mixing device and the first mixing device passes through and from this sufficiently compacted form is passed to the extruder screws of the extruder.

b. Furthermore, the first mixing device can be a

Component mixture consisting of plastic and optionally further additives from the second mixing device and on the other hand, the separately supplied and for example already (eg

Conveyor) compacted wood fiber material to be supplied. In the first mixing device all components are mixed in whole or in part and transferred in sufficiently compacted form to the extruder screws of the extruder. The first mixing device is thus arranged such that the metered and portioned

Wood fiber material (which for example from the conveyor provided) with at least one further component,

For example, a plastic (for example, a thermoplastic or a thermosetting plastic) and / or an additive (such as a primer), partially or completely mixable to a mixture and can be subsequently transferred to the extrusion.

c.) Furthermore, all components (plastics, additives and / or dosed and portioned wood fibers) can be dosed separately, separated

introduced from each other and brought together only in the first mixing device, there completely or partially mixed and transferred in sufficiently compacted form to the extruder screws. Alternatively, it is conceivable that all components (plastics, additives and / or metered and portioned wood fibers) are metered separately and fed directly to the extruder separately.

If plastic and / or additives are used in granular form, it may be due to the widely varying bulk densities of the lighter, portioned wood fiber material and the heavier plastic or additive (ratio, for example, about 1: 5 to 1: 30) and because of the different particle sizes for unwanted segregation during the mixing process itself come in the first mixing device.

Similar effects can also occur with plastics and additives, which are processed in other forms than those of the granules, depending on the physical characteristics of the wood fiber material. In these cases, it has proven to be advantageous to run only the components with the higher bulk densities through the first mixing device and / or the second mixing device, while the portioned and already volumetrically or gravimetrically metered wood fiber material directly either the first mixing device or equal to the extruder is supplied. According to a further exemplary embodiment, the first mixing device has a stuffing funnel, wherein the stuffing funnel can be configured such that all components supplied

(Plastics, additives and / or dosed and portioned wood fibers) can be premixed and compacted.

The stuffing funnel may for example also have a twin screw, which is designed as a co-currently running and so the

Promotes mixing. He may further comprise a funnel-shaped container in which a stamp mixes the mixture and

pressed, which is located in the funnel.

According to another exemplary embodiment, the assembly further comprises the extruder for performing a

Extrusion process on. The extruder is in an exemplary

Embodiment set up such that the mixture, for example consisting of the portioned and metered wood fiber material and the other component, can be fed. As already explained above, as an alternative to the above embodiment, the extruder can be set up in such a way that it delivers the portioned and metered portion

Wood fiber material, the plastic and / or the additive is obtained separately, so that only in the extruder itself, a mixture of the portioned and metered wood fiber material is carried out with the other components. Examples of a fiber composite product according to an embodiment of the invention are

Automobile linings (for example profiles or injection-molded parts), aircraft linings, furniture parts (for example, chairlamps,

Floor strips), panels and other cladding elements for indoor and outdoor use (for example, terrace floors or façade profiles). Other applications are possible.

According to another exemplary embodiment, the arrangement further comprises a first component metering device Dosing the plastic and / or a second

Component dosing device for dosing the additive or other plastics. The first component metering device and / or the second component metering device can deliver the metered plastics or additives directly to the first mixing device, the second one

Provide mixing device or the extruder.

It should be noted that embodiments of the invention have been described with reference to different subject matters. In particular, some embodiments of the invention are described with apparatus claims and other embodiments of the invention with method claims. However, it will be apparent to those skilled in the art upon reading this application that, unless explicitly stated otherwise, in addition to a combination of

Characteristics belonging to a type of subject matter, also any combination of features is possible, the

different types of invention articles belong.

Brief description of the drawings

In the following, for further explanation and for better understanding of the present invention, embodiments will be described in detail with reference to the accompanying drawings.

Show it :

Fig. 1 shows an arrangement for carrying out a method for transferring wood fibers into a processable by metering state according to an exemplary

Embodiment of the invention. Fig. 2 is a diagram illustrating a typical screening characteristic of untreated refiner wood fibers of the invention.

Figs. 3 and 4 show images of fiber portions as they are

starting from a bale of untreated wood fibers according to

exemplary embodiments of the invention can be obtained.

Fig. Figure 5 shows a bale of untreated wood fibers which is portionable according to exemplary embodiments of the invention.

6 shows a schematic representation of a structure of the assembly between the metering device and the extruder according to an exemplary embodiment of the present invention.

FIG. 7 shows a schematic representation of a further construction of the arrangement between the metering device and the extruder according to an exemplary embodiment of the present invention.

8 shows a schematic representation of a further construction of the arrangement between the metering device and the extruder according to a further exemplary embodiment of the present invention

Invention.

Detailed Description of Exemplary Embodiments

The same or similar components in different figures are provided with the same reference numerals. The illustrations of the figures are schematic and not to scale.

1 shows an arrangement 100 for fiber portioning,

for example with a cutting mill 102 and subsequently

Metering device 104 with single-screw discharge according to an embodiment of the invention. The assembly 100 is provided for transferring wood fibers to a state processable by the metering device 104. The assembly 100 includes a conveyor belt as a feeder 106 for feeding pressed bales 108 as a continuous one

The wood pulp feedstock to the portioning apparatus 110 with the moving tool 102. The portioning apparatus 110 is configured to supply the supplied continuous starting material 108 of wood fibers into smaller, discrete fiber portions 112 that are predictable in size and properties while maintaining the

Split fiber structure. The size is defined by perforated plate 114. The metered quantity of fiber portions 112 provided at the outlet of the metering device 104 can then be supplied to a downstream, not shown, first mixing device 603 (see FIG. 6). Here, the fiber portions 112 may be mixed with plastic, for example. This mixture may then be fed to an extruder 605 (see FIG. 6) for producing a fiber composite product.

FIG. 2 shows an exemplary screen characteristic for the representation of the length distribution in the raw wood fiber material (refiner fibers from thermo-mechanical pulping).

FIG. 5 is a photograph showing the composition of untreated compacted bales. FIG.

Wood fiber material.

FIG. 3 and FIG. 4 show photos with fiber material after portioning of the wood fiber raw material according to FIG. 5 in accordance with the method according to an exemplary embodiment of the invention (clearly recognizable the "ball structure").

In the following, a further concrete embodiment of the invention will be described.

For example, wood fiber material, which by a

Thermomechanical pulping process from softwoods with Main part of spruce, fir and pine is obtained, which further has a moisture content between 8 - 12% and according sieve analysis one

Length distribution between a few 1/10 mm to max. 30 mm, up to 66% but between 1 and 6 mm with an average length of approx. 3 mm and an aspect ratio between 20 - 80 and in compacted form as pressed bales with a density of approx. 280 kg / m ³ may be present in the filler neck of a device with a rotating tool, such as a granulator. In various processing, the wood fiber material can be replaced by exchangeable perforated plates with different sized openings in easily dosed fiber portions, which are mainly the maximum size of

Sieve opening have, but can also take any underlying size down to the individual fiber, be divided.

For apertures of 12 mm diameter, recycled wood fiber material having a bulk density of about 0.02 kg / dm ³ can thus be obtained, whereas for openings of 8 mm diameter, this may be about 0.04 kg / dm ³ .

The bulk density in turn has a direct effect on the dosing, as at constant speed of the

Discharge device discharge levels are approximately equal to each other as the bulk densities, the amounts increase with higher bulk densities.

The thus prepared wood fiber material can be passed into a gravimetric or volumetric metering device in advance of a 2-screw extruder and in a conventional W PC recipe with, for example, 60% wood fiber content, 37% PP granules (especially MFR at 8 g / 10 min ) and 3% additive (for example

Maleic anhydride as adhesion promoter) are extruded.

Fig. 6 shows a schematic representation of the arrangement according to the invention, wherein in Fig. 6, the devices are shown, which are located between the metering device 104 and an extruder 605. In the metering device 104 is in the

Portioning device 110 portioned wood fiber material dosed into desired doses. The metering device 104 may have, for example, a gravimetric metering device, such as a weighing belt or a hopper with dosimeter, or a volumetric metering device. After the metering device 104 may be a

Transfer device 601 are arranged to transfer the metered and portioned wood fiber material portions to a conveyor 602. Subsequently, the individual metered and portioned wood fiber material portions are conveyed by the conveyor 602 to a first mixing device 603. The

Conveyor 602 may be, for example, a screw conveyor or a conveyor belt. In the conveyor 602, for example, by means of a conical screw conveyor simultaneously a compaction or compaction of the wood fiber material can be performed.

In the first mixing device 603, another component such as a plastic and / or an additive (e.g., adhesive) is mixed with the wood fiber material. The first mixing device 603 may, for example, have a stuffing funnel, so that likewise a compaction and a premixing between the wood fiber material and the further component take place. The further component can consist of a multiplicity of different plastics and additives. Before the further components are added to the wood fiber material in the first mixing device 603, the further components are mixed in a second mixing device 604. In this second

Mixer 604 is a homogeneous mixture of all components of the other component, such as a homogeneous mixing of plastics and additives made. Furthermore, in a first metering device 606, a first component of the further component, such as plastic, dosed and the second mixing device

604 supplied. In a second component metering device 607, a further constituent of the further component is metered (for example a further plastic, an additive and / or an adhesive) and fed to the second mixing device 604. Furthermore, it is conceivable that further components are supplied to the same mixing device 604 by means of further metering devices.

After the first mixing device 603 is created

A mixture of wood fiber material and the further component is provided to the extruder 605. In the extruder 605 is a

Extrusion process carried out, so that, for example, under application of pressure and temperature, a workable

Fiber composite material can be produced.

Fig. 7 shows an alternative construction of the arrangement with respect to FIG. 6. Here, for example, the metered and portioned

Wood fiber material after the metering device 104 directly to the extruder

605 supplied. Further, in the first metering device 606, the first component of the further component, such as plastic, is metered. In the second component metering device 607, the further component of the further component is metered (for example

Plastic, additive or adhesive). The metered components are also fed directly to the extruder 605 separately. In a further alternative embodiment, the first mixing device 603 is connected upstream of the extruder 605, wherein the first

Mixer 603 itself the wood fiber material that dosed

Component from the first Komponentendosiervorrichtung 606 and the metered component from the second Komponentendosiervorrichtung 607 are fed directly and separately from each other.

8 shows a representation of the arrangement according to the invention, in which all components are initially gravimetric or volumetric dosed and then the second mixing device 604 are supplied. The portioned wood fiber material first passes through the

Metering device 104, and the other components such as the plastic and, for example, the other additives pass through the first

Component dispenser 606 and / or the second

Component dispenser 607. The second

Mixer 604 provided component mixture can then be passed to the extrusion in the extruder 605. In addition, it is possible as a further intermediate step that the component mixture from the second mixing device 604 is first supplied to the first mixing device 603, is further mixed by this and in

sufficiently compacted shape to the extrusion screws of

Extruder 605 is passed.

The invention is not limited in its execution to the preferred embodiments shown in the figures. Rather, a variety of variants is conceivable, which makes use of the illustrated solution and the inventive principle even with fundamentally different types of embodiments.

In addition, it should be noted that "having" does not exclude other elements or steps and "a" or "an" does not exclude a multitude. "It should also be noted that features or steps described with reference to one of the above embodiments also may be used in combination with other features or steps of other embodiments described above

To see restrictions.

Claims

P atent claims

1. Process for transferring wood fibers into one

Dosing devices processable state, the method being characterized by

a supply of a coherent starting material made of wood fibers, and

a division of the coherent starting material made of wood fibers by a portioning device with a moving one

Tool in smaller, discrete and in size and properties

Predeterminable fiber portions while largely retaining the fiber structure.

2. The method according to claim 1, characterized in that the division of the starting material made of wood fibers into dosable fiber portions is adjusted by the size of openings in a perforated plate of the portioning device.

3. The method according to claim 2, characterized in that the step of dividing in addition to dividing into

Predeterminable fiber portions also have a division into all smaller fiber portions down to the individual fiber in the processed wood fiber material.

4. Method according to claims 1 to 3, characterized in that

the coherent wood fiber material is fed to the portioning device in a compacted form, in particular as a pressed bale.

5. Method according to claims 1 to 4, characterized in that

the portioned wood fiber material is fed to a metering device.

6. Method claim 5, characterized in that

the dosing device carries out gravimetric dosing.

7. The method according to claim 5, characterized in that the metering device carries out volumetric metering.

8. The method according to one of claims 5 to 7, characterized

marked that

the dosed portioned wood fiber material according to the

Dosing device is transported further in a transfer device.

9. Method according to one of claims 5 to 8, characterized

marked that

the portioned wood fiber material dosed in the dosing device is guided in a conveyor and is compacted therein.

10. The method according to claim 9, characterized in that the conveying device is a screw conveyor

Has a twin screw conveyor and/or a conical screw conveyor.

11. The method according to one of claims 5 to 10, characterized in that an extrusion process the dosed portioned

Wood fiber material and/or a plastic and/or an additive is supplied separately from one another.

12. The method according to one of claims 5 to 10, characterized in that

the metered portioned wood fiber material with at least one further component, in particular comprising the plastic, in particular a thermoplastic, and / or the additive, in particular as an adhesion promoter, in one of the metering device

downstream first mixing device is completely or partially mixed into a mixture.

13. The method according to claim 12, characterized in that the first mixing device has a tamping funnel and the

Mixture is completely or partially mixed and compacted in the tamping funnel.

14. The method according to claim 12 or 13, characterized in that

In a second mixing device, the plastic and the additive are mixed to form a component mixture and the

Component mixture is fed to the first mixing device.

15. The method according to one of claims 12 to 14, characterized in that

the mixture is fed to the extrusion process.

16. The method according to one of claims 5 to 10, characterized in that in the second mixing device the plastic and/or the additive and the metered portioned wood fiber material are added

Component mixture are mixed and the component mixture is fed to the first mixing device or the extrusion process.

17. The method according to one of claims 11 to 16, characterized in that

the plastic is dosed in a first component dosing device and/or the additive in a second

Component metering device is metered.

18. Wood fiber material, produced according to one or more of claims 1 to 5.

19. Wood fiber material according to claim 18, characterized in that

the wood fiber material has bulk densities between 0.015 kg/dm ³ and 0.1 kg/dm ³ , in particular bulk densities between 0.02 kg/dm ³ and 0.04 kg/dm ³ .

20. Extrudate, produced according to claims 11, 15 or

16.

21. Extrudate according to claim 20, designed in the form of a

granulated compounds, a profile or an injection molded part.

22. Extrudate according to claim 20 or 21, characterized in that the wood fiber content in the extrudate accounts for a mass fraction

Total composite occupies between 20% and 80%, in particular between 50% and 70%.

23. Fiber composite product made from a wood fiber material according to claim 18 or 19 or from an extrudate according to claims 20 to 22.

24. Arrangement for converting wood fibers into a state that can be processed by metering devices, the arrangement having:

a feeding device for feeding a coherent starting material made of wood fibers;

a portioning device with a moving tool, which is set up to divide the supplied coherent starting material made of wood fibers into smaller, discrete fiber portions that can be predetermined in size and properties while largely maintaining the fiber structure.

25. Arrangement according to claim 24, characterized in that the portioning device has a perforated plate,

wherein the perforated plate is arranged below an engagement area of the moving tool and closes off a working space of the tool at the bottom.

26. Arrangement according to claim 25, characterized in that the moving tool is a rotating tool running in front of the perforated plate, and

that the division into dosable fiber portions is carried out by the rotating tool.

27. Arrangement according to claim 26, characterized in that the rotating tool for dividing into dosable fiber portions

Cutting knife or a roller-shaped tool with a for

Division of suitable surface with ridges, pins, ridges or spines.

28. Arrangement according to one of claims 24 to 27, comprising a metering device for metering a predeterminable amount of the portioned wood fiber material.

29. Arrangement according to claim 28, characterized in that the dosing device has a supply funnel including dosing control and

Has material discharge.

30. Arrangement according to claim 28 or 29,

wherein the dosing device is designed such that gravimetric and/or volumetric dosing can be carried out.

31. Arrangement according to one of claims 28 to 30, further comprising

a transfer device, which is set up, the dosed portioned wood fiber material after the dosing device

to carry on.

32. Arrangement according to one of claims 28 to 31, further comprising

a conveyor device which is set up to guide and compact the metered portioned wood fiber material after the metering device.

33. Arrangement according to claim 32, characterized in that the conveying device is a screw conveyor

Has a twin screw conveyor and/or a conical screw conveyor.

34. Arrangement according to one of claims 28 to 33, further comprising

an extruder for carrying out an extrusion process, the extruder being set up in such a way that the metered portioned wood fiber material and/or a plastic and/or a

Additive can be supplied separately from each other.

35. Arrangement according to one of claims 28 to 33, further comprising

a first mixing device, which is connected downstream of the metering device and the first mixing device is set up in such a way that the metered portioned wood fiber material is mixed with at least one further component, in particular comprising the plastic, in particular a thermoplastic, and/or the additive, in particular an adhesion promoter Mixture is miscible.

36. Arrangement according to claim 35, characterized in that the first mixing device has a stuffing funnel,

wherein the stuffing funnel is designed such that the mixture is miscible and compactable.

37. Arrangement according to claim 34 or 36, further comprising a second mixing device, which is designed such that the plastic and the additive can be mixed to form a component mixture, and

wherein the second mixing device is set up in such a way that

Component mixture can be fed to the first mixing device.

38. Arrangement according to one of claims 35 to 37, further comprising

the extruder for carrying out an extrusion process, the extruder being set up in such a way that the mixture can be fed.

39. Arrangement according to one of claims 34 to 38, further comprising

a first component metering device for metering the plastic, and

a second component metering device for metering the additive.