EP0400359A2 - Method and device for the production of a coherent fleece of long fibres subsequently pressed into blocks or similar articles - Google Patents

Abstract

The invention relates to a process and to a device for producing a coherent web from long slivers which are produced by breaking-up the raw material fed and are then compacted to give a web which is subsequently glued and then pressed together with other webs to give blocks or the like. The raw material used is sticks or slabs which are split parallel to the fibers by vertically oscillating cutting motions, to give long slivers which are then compacted by ramming to give a web.

Description

The invention relates to a method and an apparatus for producing a coherent nonwoven from long splinters, which are produced by disassembling the supplied starting material and then compressed to form a nonwoven, which is subsequently glued and together with other nonwovens into blocks or the like. is pressed.

A corresponding method and devices for carrying out the method can be found, for example, in DE-OS 27 16 748. The aim here is to create a compressed wood product which, in contrast to conventional chipboard, is composed of elongated chips, which are arranged largely parallel to each other. Natural wood is used as the starting material, which is acted upon by squeeze rollers in such a way that the wood is broken down parallel to the fibers to form a still-connected nonwoven. To support this crushing resolution, longitudinal notches or the like can be made in the natural wood from above. be introduced.

The production of such squeeze wood was described for the first time in Holz-Zentralblatt, Stuttgart, No. 11 of January 25, 1967 (essay "Squeeze wood - a new raw material for the pulp industry"). Other publications relating to this product are PCT-WO 85/02366, WO 85/02367, WO 85/02368, WO 85/02369 and WO 85/02370. US Pat. No. 3,674,219 still appears comparable.

The pinch of the wood common to this prior art for loosening its fiber composite and producing a mat from wood fiber sections still firmly connected to one another appears to be disadvantageous in several respects, but above all requires a very high expenditure of energy.

The object of the invention is to develop an improved method and an improved device for producing the nonwovens explained at the outset.

• a) Als Ausgangsmaterial werden Spreißel oder Schwarten ver­wendet, die neben- und übereinander angenähert parallel zu­einander in Längsrichtung ausgerichtet und zu einem endlosen Paketstrang angenähert gleicher Breite und Höhe egalisiert werden;
• b) dieser Paketstrang wird in Längsrichtung der Spreißel oder Schwarten angenähert horizontal vorgefördert und dabei von oben mit Druckkräften beaufschlagt, um ein Ausweichen bei der nachfolgenden Zerlegung zu verhindern;
• c) der Paketstrang wird anschließend durch eine Zerlegungs­vorrichtung hindurchgeführt, in der die einzelnen Spreißel oder Schwarten in Längsrichtung durch lotrechte Schnittbewe­gungen in kurzer Taktfolge in einzelne, faserparallel von­einander getrennte Langsplitter gespalten werden, wobei der Paketstrang an Höhe abnimmt, an Breite jedoch zunimmt;
• d) diese Langsplitter werden anschließend durch von oben auf sie einwirkende Stampfung zu einem Vlies verdichtet.

With regard to the process, this task is solved by the following process steps:

• a) As a starting material, chisels or rinds are used, which are aligned side by side and one above the other, approximately parallel to one another in the longitudinal direction and leveled to form an endless package strand of approximately the same width and height;
• b) this bundle of parcels is conveyed approximately horizontally in the longitudinal direction of the splitters or rinds and in the process is subjected to pressure forces from above in order to prevent evasion during the subsequent disassembly;
• c) the parcel strand is then passed through a disassembling device in which the individual splitters or rinds are split in the longitudinal direction by perpendicular cutting movements in a short cycle into individual longitudinal splinters separated from one another in a fiber-parallel manner, the parcel strand decreasing in height but increasing in width;
• d) these long splinters are then compacted into a nonwoven by stamping on them from above.

According to the invention, no solid wood is used as the starting material, but rather chisels and rinds if necessary. While prior art debarking of the starting material is required, this is not necessary according to the invention. The energy-consuming squeezing process is replaced according to the invention by a fiber-parallel splitting process. Contrary to the previously known methods, the fiber composite is not only loosened according to the invention to form a mat in which the fiber sections are still firmly connected, but the stacked starting material is split into individual, that is to say completely separate, longitudinal splinters, the cross sections of which are preferably on average 100 mm², but maximum Should be 200 mm². It is spoken of "cutting movements"; however, these should be carried out in connection with the preferably continuous feed of the package strand in such a way that a splitting process results in the wood material, that is to say an air gap precedes the knife edge in the wood.

Before being processed, the splinters or rinds can already be combined in individual bundles and separated from these bundles to form the endless package strand. It is useful if the package strand to one level is equalized, which is considerably smaller than the diameter of a collar.

On their way between the individual cutting processes, the splinters or rinds are acted upon from above with their compressive forces, in order to compress the stacked starting material firmly during its longitudinal decomposition.
Due to the longitudinal division of the splinters or rinds as a result of the repeated longitudinal splitting, internal tensions in the wood are released and lead to a fabric-like mat formed from longitudinal splinters lying loosely next to or on top of one another. This mat-like structure is then compressed into a fleece by the tamping provided according to the invention. The pressure of the tamper can be adjusted so that the fiber composite can be loosened in a preselectable manner, which cannot be achieved with squeeze rollers.

In order to intensify the mutual felting of the long splinters during the formation of the fabric, it can be advantageous if the long splinters are guided on paths which intersect at an acute angle. As a result, the spreading effect is further supported, which already results from the longitudinal splitting, in which the longitudinal splinters formed from a splitter are slightly deflected from the original conveying direction on both sides by the splitting knife, which divides them lengthwise, so that subsequently there is a different direction course.

In principle, it would be possible to perform longitudinal splitting in a short cycle with splitting knives, the cutting edges of which are aligned horizontally and parallel to the fibers. However, longitudinal gaps, which are carried out with perpendicularly oscillating cutting movements of splitting knives, the cutting edges of which are at least approximately perpendicular, have proven to be advantageous, but in particular energy-saving, so that the splitting is carried out against the direction of the wood advance.

A particular advantage of the method according to the invention is that it does not process logs, but chisels and possibly rinds, which can normally be stacked on top of each other in several layers. Here, raw material of any length can be used, while in the prior art cut logs are required. It is also advantageous that it is possible to work with controllable feed and cutting forces in the method according to the invention. The connection of the individual, previously produced long splinters to form a transportable, coherent fleece takes place according to the invention exclusively by applying pressure. Any bark is separated or crumbled during the longitudinal cutting of the splinters or rinds and can thus be easily removed.

If the splitters or rinds are combined in bundles before they are processed, then it is advantageous if the package strand is then leveled to a height which is considerably smaller than the diameter of a bundle.

According to the invention, the oscillation of the cutting movements for generating the long splinters can be up to 80 Hz. For the subsequent formation of the nonwoven, it is advantageous if the tamping which acts on the long splinters or the braid to compress them from above exerts a sudden, sudden, high force action, a stored energy being converted in the range of milliseconds without large kinetic energies being developed have to. The fleece pressed in this way can then be subjected to thickness equalization. The parcel strand or the braid can be fed continuously at the same speed. As a result, a material jam combined with a compression of the longitudinal splinters, which burst open like a needle under this force, is achieved, inter alia, before the discontinuous stamping. This improves the matting, the effect mentioned being controllable.

• a) Ein Förderer für einen endlosen, aus längs ausgerichteten Spreißeln oder Schwarten bestehenden Paketstrang;
• b) eine oberhalb diese Förderers angeordnete, sich über die Förderbreite erstreckende und lotrecht nach unten wirkende, auf dem Paketstrang abrollende Druckvorrichtung;
• c) eine dem Förderer nachgeschaltete Zerlegungsvorrichtung, bestehend aus mehreren, quer zur Förderrichtung ausgerichte­ten, hintereinander und zueinander versetzt angeordneten Messerreihen, die sich jeweils aus mehreren, in lichtem Ab­stand nebeneinander angeordneten Spaltmessern zusammen­setzen, die lotrecht verschiebbar geführt sind und einem An­trieb mit kurzer Taktfolge unterliegen;
• d) der Zerlegungsvorrichtung ist eine Verdichtungseinrich­tung nachgeschaltet, in der die zuvor gespaltenen Lang­splitter zu einem Vlies verdichtet werden.

With regard to the device, the object on which the invention is based is achieved by the following features:

• a) A conveyor for an endless package strand consisting of longitudinally oriented splitters or rinds;
• b) a pressure device which is arranged above this conveyor, extends across the conveyor width and acts vertically downwards, and rolls on the package strand;
• c) a dismantling device connected downstream of the conveyor, consisting of a plurality of rows of knives aligned transversely to the direction of conveyance, one behind the other and offset from one another, each composed of a plurality of splitting knives which are arranged next to one another at a short distance from one another and are guided vertically displaceably and are subject to a drive with a short cycle sequence ;
• d) the disassembly device is followed by a compacting device in which the previously split long fragments are compacted to form a fleece.

It may also be advantageous if guide elements for deflecting the longitudinally split splinters or rinds or elongated splinters are arranged within the dismantling device over their increasing conveying width in such a way that guide paths intersecting at an acute angle are formed for them.

A metering device can be connected upstream of the parcel strand conveyor to separate the splitters or rinds from bundles supplied. The pressure device upstream of the disassembly device can preferably pressure rollers and / or pressure have balls that can be actuated via interconnected hydraulic cylinders, the pressure rollers are preferably floating. This results in an optimal adaptation of the printing device to the surface contour of the package strand.

In order to improve or ensure the parallel guidance of the splinters or rinds, the pressure device upstream of the disassembly device can have pressers with guide webs.

In order to avoid wedging of the splitters or rinds between the splitting knives, it is advantageous if the distance between the cutting edges of two splitting knives arranged in a row next to one another is smaller than between the rear knife edges.

The pressure devices provided in the disassembly device can also comprise floating, freely rotating pressure rollers. So that the vertically arranged splitting knives do not pull up the respectively applied splinters or rinds during their stroke movement, it can be expedient if the splitting knives are arranged inclined against the conveying direction and thereby enclose an acute angle with the latter.

The compression device downstream of the disassembly device can be composed of several force units, which convert the energy stored in them in a rapid cycle in the range of milliseconds. It is expedient if force units such as those used in German are used both for the oscillating drive of the splitting knife and for the drive of the compression device Patent specification 26 00 948 are described.

Further features of the invention are the subject of the subclaims and are explained in more detail with further advantages of the invention using exemplary embodiments.

• Figur 1 in Seitenansicht eine Anlage zur Herstellung eines Vlieses aus Langsplittern;
• Figur 2 in vergrößertem Maßstab einen Anlagenabschnitt gemäß Figur 1 in Draufsicht und zum Teil im Horizontalschnitt;
• Figur 3 in gegenüber der Figur 1 vergrößertem Maßstab eine Druckvorrichtung in Stirnansicht und zum Teil im Querschnitt;
• Figur 4 ein Detail der Figur 2 in vergrößertem Maßstab und in abgewandelter Ausführungsform und
• Figur 5 in gegenüber Figur 1 vergrößertem Maßstab ein Detail der Figur 1 in abgewandelter Ausführungs­form.

Some exemplary embodiments of the invention are shown schematically in the drawing. Show it:

• Figure 1 in side view of a plant for producing a nonwoven from long splinters;
• Figure 2 on an enlarged scale a system section according to Figure 1 in plan view and partly in horizontal section;
• Figure 3 on a larger scale than Figure 1, a printing device in front view and partly in cross section;
• Figure 4 shows a detail of Figure 2 on an enlarged scale and in a modified embodiment and
• Figure 5 on a larger scale than Figure 1 shows a detail of Figure 1 in a modified embodiment.

The system shown in FIG. 1 begins with a conveyor 1 for an endless package strand 2 consisting of longitudinally aligned splitters or rinds. Above the conveyor 1 there is arranged a pressure device 3 which extends across the conveyor width and acts vertically downwards and which forms the top of the package strand 2 acted upon and rolls on this. Figure 3 shows a presser 4 of this printing device 3, the pressure rollers 5 and / or pressure balls and guide webs 6 for better parallel guidance of the splay 7 or rinds.

Downstream of the printing device 3 is a disassembly device 8, which has a plurality of rows of knives 10 which are aligned transversely to the conveying direction 9 and which are arranged one behind the other and offset from one another, each of which is composed of a plurality of splitting knives 11 arranged a short distance apart with the bundle strand 2 opposing vertical blades 12. The splitting knives 11 are guided so as to be vertically displaceable and are subject to an oscillating drive 13. At least the splitting knives 11 of a row of knives 10 are arranged in a common gate 14 (see FIG. 5) which is acted upon by the oscillating drive 13, not shown in any more detail. The conveyor which transports the parcel strand 2 through the dismantling device 8 is formed by driven chains 15, which are carried out between the splitting knives 11 and are arranged in an interleaved manner. In the disassembling device 8, pressing devices 16 are arranged between the individual rows of knives 10, which in turn can have pressure rollers and / or pressure balls and firmly compress the parcel strand 2 from above on the way through the disassembling device 8.

The dismantling device 8 is followed by a compression device 17, in which the previously split long fragments are compressed into a fleece 18. The disassembly device 8 is followed by a plate belt 19 as a conveyor for the fleece 18. A leveling roller 20 is arranged downstream of the compacting device 17.

FIG. 2 shows the area of the dismantling device 8, the pressing devices 16 provided between the rows of knives 10 not being shown for reasons of better clarity. In the area of this disassembly device 8 (and subsequently in the area of the sealing device 17 and the Egali sierwalze 20) the package strand 2 increases in height but in width. The dismantling device 8 is preceded by a leveling roller 21 and the compression device 17 composed of a plurality of force units 17a is connected downstream. Guide elements 22 for deflecting the longitudinally split splinters or rinds or longitudinal splinters are arranged within the dismantling device 8 over their increasing conveying width in such a way that guide paths 23 which intersect at an acute angle are formed for them.

FIG. 4 shows that the distance a between the cutting edges 12 of two gap knives 11 arranged side by side in a row 10 is smaller than between the rear knife edges. The thickness of the knives 11 designed with a sharp cutting edge 12 is preferably 2-3 mm. The knife stroke can be around 200 mm.

The splitters or rinds used as the starting material are aligned side by side and one above the other, approximately parallel to one another in the longitudinal direction and equalized to form the endless package strand 2 of approximately the same width and height. This parcel strand, which is conveyed continuously or discontinuously on the conveyor 1, is acted upon by the printing device 3 in order to prevent evasion during the subsequent dismantling. The chain strand 2 is then transported by the disassembling device 8 in the conveying direction 9 from the chain conveyor 15. At the end, the packet strand 2 comes into the range of action of the splitting knives 11, which perform vertical oscillating cutting movements and which, with their vertical cutting edges 12, split the splinters or rinds in the longitudinal direction counter to their feed direction 9, longitudinal splits resulting from the repeated longitudinal splitting, which are separated from one another in a fiber-parallel manner. In order to intensify their matting, the guide elements 22 indicated in FIG. 2 are provided. By the arrangement of the genann th guideways 23 ensures that the long fragments cross on their way through the separating device 8 and thus form a fabric, which is then compressed by the downstream compression device 17, which exerts a pounding on the fabric from above, to form the fleece 18 which the long splinters are mainly arranged in their longitudinal direction.

Claims (30)

1. A process for producing a coherent nonwoven from elongated splinters, which are produced by disassembling the starting material supplied and then compressed to form a nonwoven which is subsequently glued and then together with other nonwovens to form blocks or the like. is pressed, characterized by the following process steps: a) As a starting material, chisels or rinds are used, which are aligned side by side and one above the other, approximately parallel to one another in the longitudinal direction and leveled to form an endless package strand of approximately the same width and height; b) this bundle of parcels is conveyed approximately horizontally in the longitudinal direction of the splitters or rinds and in the process is subjected to pressure forces from above in order to prevent evasion during the subsequent disassembly; c) the parcel strand is then passed through a disassembling device in which the individual splitters or rinds in the longitudinal direction by vertical cutting movements in a short cycle into individual, longitudinal splinters separated from one another in a fiber-parallel manner are split, the packet strand decreasing in height but increasing in width; d) these long splinters are then compacted into a nonwoven by stamping on them from above. 2. The method according to claim 1, characterized in that the longitudinal splinters are guided on paths crossing at an acute angle to form a braid. 3. The method according to claim 1 or 2, characterized in that longitudinal splinters with cross sections of on average 100 mm², maximum 200 mm² are generated. 4. The method according to claim 1, 2 or 3, characterized in that the individual chisels or rinds are split against their direction of advance by perpendicularly oscillating cutting movements in longitudinal splinters. 5. The method according to any one of the preceding claims, characterized in that the splinters or rinds are combined into individual bundles prior to their processing and are separated out from these bundles to form the endless packet strand. 6. The method according to claim 5, characterized in that the packet strand is leveled to a height which is considerably smaller than the diameter of a federal government. 7. The method according to any one of the preceding claims, characterized in that the package strand or its splinter or rinds are successively acted upon by several perpendicularly oscillating cutting movements. 8. The method according to any one of the preceding claims, characterized in that the oscillation of the cutting movements is up to 80 Hz. 9. The method according to claim 7 or 8, characterized in that the splinters or rinds are acted upon on their way between the individual cutting operations from above with their feed-promoting pressure forces. 10. The method according to any one of the preceding claims, characterized in that the longitudinal splinters or the braid for compressing them from above, a sudden, sudden high force exertion exerts a stored energy is converted in the range of milliseconds without large kinetic Energies need to be developed. 11. The method according to any one of the preceding claims, characterized in that the pressed fleece is subjected to a thickness equalization. 12. The method according to any one of the preceding claims, characterized by the use of non-barked starting material of any length. 13. The method according to claim 9, characterized in that the bark is separated and removed when disassembling the splinter or rind or when forming the braid. 14. The method according to any one of the preceding claims, characterized in that the packet strand, which is preferably fed continuously continuously at the same speed, is transported in a load-bearing manner by the disassembly device. 15. Device for the production of a coherent fleece from long splinters, which are produced by disassembling the supplied starting material and then compressed to form a fleece, which is subsequently glued and then together with other fleeces to form blocks or the like. is pressed, in particular for carrying out the method according to one of the preceding claims, characterized by the following features: a) A conveyor (1) for an endless package strand (2) consisting of longitudinally aligned splitters or rinds; b) a pressure device (3) arranged above this conveyor (1), which extends across the conveyor width and acts vertically downward, and rolls on the package strand (2); c) a dismantling device (8) connected downstream of the conveyor (1), consisting of a plurality of rows of knives (10) which are aligned transversely to the direction of conveyance (9) and which are arranged one behind the other and offset from one another, each consisting of a plurality of splitting knives (11 ) put together, which are guided vertically displaceable and are subject to a drive (13) with a short cycle sequence; d) the disassembly device (8) is followed by a compression device (17) in which the previously split long fragments are compressed to form a fleece (18). 16. The apparatus according to claim 15, characterized in that guide elements (22) for deflecting the longitudinally split splinters or rinds or longitudinal splinters are arranged within the dismantling device over their increasing conveying width in such a way that guiding paths (23) intersecting at an acute angle are formed for them. 17. The apparatus according to claim 15 or 16, characterized in that the package strand conveyor (1) is preceded by a metering device for separating the spreader (7) or rinds from bundles supplied. 18. The apparatus of claim 15, 16 or 17, characterized by a leveling device associated with the package strand conveyor (1) to form a package strand (2) approximately the same width and height. 19. Device according to one of claims 15 to 18, characterized in that the decomposition device (8) upstream pressure device (3) has pressure rollers (5) and / or pressure balls which can be actuated via interconnected hydraulic cylinders. 20. The apparatus according to claim 19, characterized in that the pressure rollers (5) are floating. 21. The apparatus of claim 15 or 16, characterized in that the disassembling device (8) upstream pressure device (3) presser (4) with guide webs (6) for better parallel guidance of the splinters (7) or rinds. 22. Device according to one of claims 15 to 21, characterized in that the splitting knives (11) are arranged at least approximately vertically with the package strand (2) opposite, approximately perpendicular cutting edges (12). 23. The device according to claim 22, characterized in that the distance (a) between the cutting edges (12) of two gap knives (11) arranged side by side in a row (10) is smaller than between the rear knife edges. 24. Device according to one of claims 15 to 23, characterized in that at least the splitting knife (11) of a row (10) are arranged in a common gate (14) which is acted upon by an oscillating drive (13). 25. Device according to one of claims 15 to 24, characterized in that the conveyor is formed by the disassembling device (8) by driven chains (15) carried out between the splitting knives (11). 26. Device according to one of claims 15 to 25, characterized in that the dismantling device (8) as För which is followed by a plate belt (19) for the fleece (18). 27. The device according to one of claims 15 to 26, characterized in that in the disassembly device (8) between the individual rows of knives (10) pressure devices (16) are arranged, which the package strand (2) or the braid that forms on the way squeeze firmly from above by the disassembly device (8). 28. The apparatus according to claim 27, characterized in that the pressing devices (16) comprise floating, freely rotating pressure rollers. 29. Device according to one of claims 15 to 28, characterized in that the splitting knives (11) are arranged inclined against the conveying direction (9) and thereby enclose an acute angle with this. 30. Device according to one of claims 15 to 29, characterized in that the decomposition device (8) downstream compression device (17) is composed of several force units (17a) which convert the energy stored in them in a rapid cycle in the range of milliseconds.

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