NL2019892B1

NL2019892B1 - Method and device for producing a ribbon of bamboo fiber

Info

Publication number: NL2019892B1
Application number: NL2019892A
Authority: NL
Inventors: Anton Hubertus Bokeloh Marcus; Martinus Van Opdorp Robertus
Original assignee: Bambooder Biobased Fiber B V
Priority date: 2017-11-13
Filing date: 2017-11-13
Publication date: 2019-05-17

Abstract

The present invention relates to a method of producing a ribbon (12) comprising bamboo fibers (14), the method comprising: - positioning the fibers (14) on a conveyor (16) and conveying the fibers in a transport direction, - interconnecting the fibers (14) by: o covering the fibers with thread (42) and/or particles of a sticky material with at least one web forming device (40) which is positioned above and/or below the conveyor and which ejects thread and/or particles, wherein the formed thread and/or particles attaches to the fibers and forms a web (45) which interconnects the fibers in order to form the ribbon, and/or o stitching the fibres together with at least one stitching device (40B) which is configured to stitch the individual fibers together in order to form the ribbon.

Description

P33326NL00/WHA

Title: Method and device for producing a ribbon of bamboo fiber

FIELD OF THE INVENTION

The present invention relates to a method and device for producing a ribboncomprising bamboo fibers. The present invention further relates to ribbon produced with themethod and device and to a composite product made with the ribbon. The present inventionfurther relates to a method and device for splitting bamboo into fibers. The present inventionfurther relates to a method of forming a product from the ribbon and to the product which isformed from the ribbon.

BACKGROUND OF THE INVENTION

Bamboo is known as a construction material. Composite products which are madefrom bamboo parts or from bamboo fibers are also known.

However, it remains quite difficult to divide bamboo stems into fibers and to use thesefibers in products. In the prior art, a “wet” extraction process is known in which bamboo partsare cut into short segments. The segments are immersed (drenched) in water. Subsequently,the fibers are formed in an elaborate process. A disadvantage of this process is that the fibersbecome wet. In the further downstream process, the fibers need to be dry. For this reason, adrying operation is required which requires a large amount of energy. A “dry” process is also known in which bamboo stems are crushed or cracked intosmaller pieces which are then used in further processing and converted into products. Thisprocess works, but has as a disadvantage that the individual bamboo pieces have a varyingsize and shape, which makes the processing difficult. Furthermore, the crushing or crackinghas a result that at least a part of the individual bamboo fibers of which the bamboo stems areformed are broken, which results in smaller pieces having a decreased strength. Furthermore,the fibers may have different lengths and may be difficult to align.

OBJECT OF THE INVENTION

It is an object of the invention to provide a better method and device for splittingbamboo parts into thin fibers which are suitable to be used in a further process.

It is a further object of the present invention to provide a method and device forinterconnecting these bamboo fibers into a ribbon or mat, which is suitable for producing fibrereinforced products.

It is a further object of the present invention to provide a method and device forproducing flakes comprising interconnected bamboo fibers.

It is a further object of the present invention to provide fiber reinforced productscomprising bamboo fibers, made from the ribbon, mat or flakes.

SUMMARY OF THE INVENTION

In order to achieve at least one object, a method of producing a ribbon comprisingbamboo fibers is provided, the method comprising: - positioning the fibers on a conveyor and conveying the fibers in a transportdirection, - interconnecting the fibers by: o covering the fibers with thread and/or particles of a sticky material with at leastone web forming device which is positioned above and/or below the conveyorand which ejects thread and/or particles, wherein the formed thread and/orparticles attaches to the fibers and forms a web which interconnects the fibersin order to form the ribbon, and/or o stitching the fibres together with at least one stitching device which isconfigured to stitch the individual fibers together in order to form the ribbon.

With the method, bamboo fibers can be arranged and interconnected into a ribbon.The ribbon can be used for producing fiber reinforced products having bamboo fibers.

The present invention further relates to a ribbon forming device for forming a ribboncomprising bamboo fibers, the ribbon forming device comprising: at least one conveyor for conveying the fibers in a transport direction,a depositing station where fibers are deposited onto the conveyor,at least one web forming device positioned above and/or below the conveyordownstream of the depositing station for covering the fibers with thread (42) and/or particles of a sticky material, wherein the thread and/or particles form atleast one web (45) which interconnects the fibers into a ribbon, and/or at leastone stitching device (40B) positioned downstream of the depositing station,wherein the at least one stitching device is configured to stitch the individualfibers together.

The device provides the same advantages as the method.

The present invention further relates to a ribbon comprising bamboo fibers, whereinthe bamboo fibers are interconnected by thread and/or particles which are interconnected andform a web and/or are interconnected by stitches.

The present invention further relates to a ribbon in the form of a roll. The ribbon maybe rolled onto itself or may be rolled on a bobbin.

The ribbon may be cut to a required width, in particular prior to being rolled into a roll.The parts which are cut from the right and/or left side of the ribbon may be processed intoflakes and form a semi-manufactured product. The flakes may be used as intermediateproducts to manufacture further composite products in a further downstream process.

The present invention further relates to a method of manufacturing a fiber reinforcedproduct from the ribbon, the method comprising: forming the ribbon, a piece which is cut from the ribbon or the flakes into a pre-defined shape, in particular by positioning the ribbon, piece or flakes on amandrel or in a mould,impregnating the ribbon or flakes with resin,letting the resin harden.

The resin may be any resin known in the field of the art, e.g. a thermoplastic orthermosetting resin such as, polycarbonate, polyester resin, vinyl ester resin, epoxy resin,phenolic resin, urethane. Obviously, many more resins are known in the field of the art.

The present invention further relates to a fiber reinforced product comprising theribbon according to the invention or flakes obtained with the method according to theinvention and/or the flakes obtained with the device according to the invention, wherein theribbon is impregnated with resin which is cured.

The present invention further relates to a fiber forming device for splitting a bamboopart into fibers, wherein the fiber forming device is in particular configured to be used in themethod according to the invention and in the ribbon forming device according to the invention,the fiber forming device comprising: - a bamboo part splitting device configured for splitting a flat piece of bamboo froma bamboo part, the bamboo part splitting device comprising: o at least a first rotary member and a second rotary member for guiding thebamboo part between them, o at least one splitting edge positioned downstream from the first andsecond rotary member for splitting a flat piece of bamboo from the bamboopart, - a flat piece splitting device for splitting each flat piece which exits the bamboo partsplitting device into fibers.

The fiber forming device advantageously allows the forming of thin fibers from bambooparts. The fibers are a formed along the fiber direction, resulting in fibers of a predefinedlength, width and height (or thickness). The device was found to be reliable and suitable forefficient production of the fibers, with a limited loss of material.

The fibers which exit the flat piece splitting device are substantially parallel and exitthe flat piece splitting device as a group (or bundle) of aligned fibers which are arrangedparallel and adjacent one another. The fibers have front ends which are substantially alignedand rear ends which are substantially aligned. The fibers are ready for further processing.The fibers are in particular ready to be deposited onto the conveyor of the ribbon formingdevice according to the present invention. The flat piece splitting device may advantageouslyseparate the fibers from wood parts which are located between the fibers. These wood partscan be removed.

In one possible embodiment, the fiber forming device may comprise an upstreammodule positioned upstream from the bamboo part splitting device. The upstream module isconfigured for creating the flat pieces of bamboo which are fed to the bamboo part splittingdevice from a tubular bamboo segment. The upstream module may comprise a rolling mill fordividing the tubular bamboo segment in an axial direction thereof into tube segments. Thesplitting device of the upstream module is configured to split the tube segments into flatpieces of bamboo which can be fed to the bamboo part splitting device. Such an upstreammodule is known from the prior art and does not form part of the present invention by itself.

The present invention further relates to a method of splitting a bamboo part intomultiple fibers, the method comprising: - inserting a bamboo part into the fiber forming device according to the invention, - splitting a flat piece from the bamboo part with the bamboo part splitting device, - splitting the flat piece into multiple fibers with the flat piece splitting device.

The method provides the same advantages as the fiber forming device according tothe invention.

The present invention further relates to a flat piece splitting device for splitting a flatpiece of bamboo into a plurality of fibers, the flat piece splitting device comprising: - a first rotary element configured for rotation about a first axis, and - a second rotary element configured for rotation about a second axis,the first and second axis being parallel, wherein the first rotary element comprises a plurality of first splitting members havinga first diameter (D1) and a plurality of second splitting members having a second, differentdiameter (D2), wherein the first and second splitting members are alternately positioned alongthe first rotation axis, wherein the second rotary element comprises a plurality of third splitting membershaving a third diameter and a plurality of fourth splitting members having a fourth diameterwhich is different from the third diameter, wherein the third and fourth splitting members arealternately positioned along the second rotation axis, wherein the first, second, third and fourth splitting members comprise a circumferentialsplitting surface, wherein the first splitting members are positioned opposite the third splitting membersand the second splitting members are positioned opposite the fourth splitting members,wherein a first series of passages are defined between the first and third splitting membersand a second series of passages are defined between the second and fourth splittingmembers, wherein the first and second series are located at a passage distance from oneanother.

It was found that the flat piece splitting device allows splitting of a flat piece of bamboointo individual fibers in an effective and reliable way, allowing high throughput with limited lossof material. The splitting occurs at a distance upstream of the first and second rotaryelements. As a result, the fibers are advantageously split according to their natural fiberdirection, resulting in fibers of a predetermined length, width and height. In addition the fibersmay be separated from wood parts which are located between the fibers.

During the splitting of the flat piece, the fibers which are formed and which are locatedadjacent one another are pulled away from one another because a first fiber to be formed isforced to travel through a first passage being part of the first series of passages. An adjacentsecond fiber to be formed is forced to travel through a second passage being part of thesecond series of passages. Because the first and second passage are spaced apart, thefibers are pulled away from one another. The fibers are split at a distance upstream of the firstand second rotary element as a result of this. This effectively results in a splitting along thenatural direction of the fibers themselves, with the beneficial consequence that the fibers stayintact over their length. Ultimately, this results in a stronger composite end product.

The present invention further relates to a fiber cleaning device for cleaning bamboobamboo fibers, comprising: a first rotary cleaning member and a second rotary cleaningmember which define a passageway between them. The cleaning device may form part of theflat piece splitting device or may stand on its own.

These and other aspects of the invention will be more readily appreciated as the samebecomes better understood by reference to the following detailed description and consideredin connection with the accompanying drawings in which like reference symbols designate likeparts.

SHORT DESCRIPTION OF THE FIGURES

Fig. 1A shows an isometric view of a ribbon forming device according to the invention.

Fig. 1B shows an isometric view of another embodiment of a ribbon forming deviceaccording to the invention.

Fig. 1C shows an isometric view of a further possible embodiment of a ribbon formingdevice according to the invention.

Fig. 1D shows an isometric view of yet a further possible embodiment of a ribbonforming device according to the invention.

Fig. 1E shows a partial view of again a further possible embodiment of a ribbonforming device according to the invention.

Fig. 2A shows an isometric view of yet another embodiment of a ribbon forming deviceaccording to the invention.

Fig. 2B shows a partial isometric view of an embodiment of a ribbon forming deviceaccording to the invention comprising a pick and place robot.

Fig. 3 shows an isometric view of a further embodiment of a ribbon forming deviceaccording to the invention.

Fig. 4 shows an isometric view of again another embodiment of a flake forming deviceaccording to the invention.

Fig. 5 shows a side view of a part of a bamboo part splitting device which is part of afiber forming device according to the invention.

Fig. 6A shows a side view of a fiber forming device according to the invention.

Fig. 6B shows a side view of another embodiment of a fiber forming device accordingto the invention.

Fig. 6C shows a side view of yet another embodiment of a fiber forming deviceaccording to the invention.

Fig. 7 shows an isometric view of a flat piece splitting device according to theinvention.

Fig. 8 shows a front view of the flat piece splitting device according to fig. 7.

Fig. 9 shows an example of the manufacturing of a product with the ribbon accordingto the invention, the fibers having a fixed overlap and opposed directions.

Fig. 10 shows an example of the manufacturing of another product with the ribbonaccording to the invention, the fibers having a fixed overlap and mutiple directions.

Fig. 11 shows an example of the manufacturing of yet another product with the ribbonaccording to the invention, the fibers being parallel.

Fig. 12 shows an example of the manufacturing of a further product with the ribbonaccording to the invention, the fibers having a fixed overlap.

Fig. 13 shows an example of the manufacturing of yet a further product with multipleribbons at the same time according to the invention, the fibers having a fixed overlap.

Fig. 14 shows a cross-sectional view of a bamboo segment which forms a basematerial for the present invention.

Fig. 15 shows an isometric view of another embodiment of a flat piece splitting deviceaccording to the invention.

Fig. 16 shows an isometric view of another embodiment of a ribbon forming deviceaccording to the present invention.

Fig. 17 shows an isometric view of a 3 dimensional preformed ribbon, formed with thedevice of fig. 16.

Fig. 18 shows an isometric view of variant of the ribbon.

Figs. 19 and 20 show a side view of an embodiment of a fiber cleaning deviceaccording to the invention.

Fig. 21 shows a side view of another embodiment of a fiber cleaning device accordingto the invention.

Fig. 22 shows an isometric view of yet another embodiment of a fiber cleaning deviceaccording to the invention.

Fig. 23 shows an isometric view of a further embodiment of a fiber cleaning deviceaccording to the invention.

DETAILED DESCRIPTION OF THE FIGURES

Ribbon forming method and device

Turning to fig. 1A, a ribbon forming device 10 is shown for forming a ribbon 12comprising fibers 14 of bamboo. The fibers 14 may in particular be bamboo fibers. The ribbon12 may have a ribbon width (Rw) of between 50mm and 500 mm. The ribbon forming devicecomprises a conveyor 16 for conveying the fibers in a transport direction (T).

The conveyor 16 may comprise an endless belt 18 which is supported by anupstream roller 19 and a downstream roller 20. The belt may comprise suction holes 21,which may have any suitable shape and size. The belt 18 may be of a thermally conductivematerial (e.g. copper) or may comprise thermally conductive covering elements. Theconveyor may comprise a suction system 22 comprising a manifold 23 positioned below thebelt 18 and a suction tube 24 which is connected to a suction pump which is known per seand not considered to form part of the invention. One or more additional support rollers 25may be present.

The conveyor 16 will typically be horizontal in the sense that it present an upwardlyfacing horizontal surface 26. The conveyor will typically move in a horizontal transportdirection T. However, an inclined orientation of the surface and an inclined orientation of thetransport direction are conceivable.

The ribbon forming device 10 comprises a depositing station 28 located at anupstream part of the conveyor 16 where the bamboo fibers 14 are deposited onto theconveyor 16. The depositing station 28 comprises a positioning device 29. In the shownembodiment, the positioning device comprises an inclined chute 30. One or more supplyopenings 33 at the end of respective one or more supply tubes 37 are provided for supplyingthe individual fibers 14 to the chute 30. The chute 30 may be provided with a controllablevibration device 31 for vibrating the chute. In this way, the fibers are spread evenly over thechute. Further the vibrating device may control the rate of discharge of the fibers 14 onto theconveyor. The chute 30 has a downstream end 32 where the fibers drop from the chute ontothe conveyor 16.

The chute may be adjustable in order to position the fibers at a predefined anglerelative to the transport direction, in particular at any angle between 20-90 degrees relative tothe transport direction. To this end, the chute may be pivotable about a vertical pivot axis 34located at the downstream end 32, in particular in the centre of the chute. The chute also has the function of a buffer and stores a number of fibers in order to create a constant flow offibers onto the conveyor.

In this document, an angle of 90 degrees of the fibers 14 relative to the transportdirection of the conveyor means a direction orthogonal to the transport direction T of theconveyor.

The fibers 14 may be deposited in contact with one another or may have a small gapbetween them, for instance a gap of between 0,1 and 0,5 mm. The fibers are deposited sideby side and in an orderly manner, i.e. with the front and rear ends being aligned.

Turning to fig. 2A, other ways of depositing the fibers 14 onto the conveyor 16 arealso possible. In this embodiment, the positioning device comprises one or more supplyconveyors 38 which may be arranged in series. The supply conveyors 38 may be driven by acontrollable drive for controlling the flow of fibers 14. At the downstream end of the supplyconveyors, one or more controllable vibration devices 31 may be provided for furthercontrolling the flow of the fibers. The supply conveyors also have the function of a buffer andstores a number of fibers 14, in order to ensure a constant flow of fibers onto the conveyor16.

Turning to fig. 2B, in another embodiment, instead of the chute 30 or the supplyconveyor(s) 38 the positioning device 29 comprises a pick-and-place robot which is providedat the upstream part of the conveyor 16. The pick and place robot may comprise a gripper.Only a part of the conveyor is shown. It will be clear for the skilled person that the rest of theribbon forming device may be as is shown in any of figures 1A-1E.

The gripper is configured for holding a plurality of unidirectional fibers 14, forinstance 10-500 fibers. The gripper may position the fibers 14 as a group of unidirectionalfibers onto the conveyor and at a predetermined angle of 0-90 degrees to the transportdirection. 0 degrees means a direction which is parallel to the transport direction To of theconveyor. 90 degrees means a direction orthogonal to the transport direction T of theconveyor.

The gripper may be positioned on the free end of a robot arm having six degrees offreedom. Such robot arms are known in the field of the art. It may be possible to use a robotarm having less degrees of freedom, depending on the specific configuration.

With reference to fig. 1A and fig. 2A, in an embodiment the ribbon forming device 10comprises a web forming device 40 positioned above the conveyor at a location downstreamof the depositing station 28 for covering the fibers with thread 42 of a sticky material. Thethread 42 forms a web 45 and interconnects the fibers into a ribbon. The thread typically isdeposited in a curved manner and may extend in random orientations and intersects itself inmultiple locations. Because the thread is sticky, it forms connections at the intersections andalso adheres to the fibers 14, thereby forming the web. 24. It will be clear that when the webis formed, the stickiness will reduce significantly and generally no longer be present or only toa limited extent. In the ribbon, the stickiness well be absent or substantially reduced.

The thread forming station 40 may comprise one or multiple thread forming elements44. The thread forming elements 44 may be stationary but may also be movable, for instancein a horizontal plane (XY plane).

The thread 42 which is formed with the web forming device may be synthetic, e.g.polyamide (nylon), polyester-derivatives, polycarbonate, polyacrylonitrile, polyvinylbutyral.The thread may also be a bio-based material e.g. pullulan (starch derivative),polycaprolactone, polylactic acid, polyoxazoline, cellulose-acetate, Chitosan/chitosine,gelatine, keratine.

The web forming device 40 may in particular be an electrospinning device.Electrospinning devices are known in the field of the art and are based on a voltagedifference between a nozzle from which the thread emerges and a target location (theconveyor) onto which the thread is to be deposited. The fibers may be a polymer material andmay be very thin, in the order of hundreds of nanometers. The polymer is liquefied andcharged. A so-called Taylor cone is formed at the nozzle. If the molecular cohesion issufficiently high, the polymer forms a thread which dries in mid-air and travels toward theconveyor, more in particular to the fibers which lie on the conveyor. Various polymers may beused.

It was found that an electrospinning device has advantages when making a ribboncomprising bamboo fibers. In particular, the web which is formed is very open. This allows thebamboo fibers to be impregnated with resin in an easy manner. Also, the web is lightweightand relatively strong. Further the web may be flexible, and in case a gap is provided betweenthe individual fibers, the web allows the ribbon to be compressed or expanded in a harmonicastyle, i.e. by curving the web and reducing or increasing the distance (or gap) between thefibers 14.

At the downstream end 55 of the conveyor, a spooling device 56 may be provided.The spooling device 56 is configured for rolling the formed ribbon 12 onto itself as a roll 58.The roll may be rolled on a bobbin or simply onto itself without a bobbin.

One or more cutting devices 36 may be provided downstream of the web formingdevice 40 for cutting the ribbon to a required width Rw, thereby advantageously creatingstraight right and left sides of the ribbon. The pieces 51 which are cut off may be used asflakes in the production of other composite products.

With reference to figs. 1B, 1C and 1D, it is also possible to provide a web formingdevice 40 on both sides of the fibers, i.e. on the top side and on the bottom side. This resultsin a stronger ribbon.

In the embodiment of fig 1B, the conveyor 16 is divided in two separate conveyors,i.e. an upstream conveyor 16A and a downstream conveyor 16B, with a gap 39 in betweenthem. A second web forming device 40B which forms a web on the bottom side of the fibers14 is positioned in the gap. The second web forming device is positioned at a distancedownstream from the first web forming device 40. In this way, the web formed by the first webforming device 40 has hardened sufficiently and prevents the fibers 14 from falling downwardthough the gap 39 between the upstream and downstream conveyors.

The thread 42 which is formed in the web forming device travels upwards as a resultof the difference in voltage between the thread forming elements 44 and the conveyor.

In the embodiment of fig. 1C, the web forming device 40 comprises a number ofextrusion nozzles which are configured to extrude threads therefrom. The formed ribbon 12with a web 45 on one side is inverted at the end of the conveyor 16. A second conveyor 16Bis provided underneath the conveyor to support the formed ribbon 12 in the inverted position.The formed ribbon with a web on one side is transferred from the first conveyor 16A to thesecond conveyor 16B during the inversion. The second conveyor 16B may be inclined orpartially inclined. A second web forming device 40B may be provided above the secondconveyor 16B to provide a second web 45 on the other side of the ribbon 12. Subsequently,the ribbon is rolled into a roll. The extrusion nozzles 44 may also be used in the embodimentsof fig. 1A and 1B.

Turning to fig. 1D, this device is largely the same as the device of fig. 1C, but theweb forming device 40 comprises a set of spray nozzles 44. The spray nozzles spray a liquidover the fibers 14. The liquid may be a thread but may also be in the form of liquid particles.

The liquid thread or particles hardens on the fibers 14 and forms the web 45 whichinterconnects the fibers 14. In case of particles, the particles at least partially interconnectwhen they land on the fibers and form the web. The web 45 is formed on both sides of theribbon, one side upstream of the inversion and the other side downstream of the inversion ofthe ribbon. The spray nozzles may also be used in the embodiments of fig. 1A and 1B.

However, a single web on one side is also possible in case of spraying or extrusion.

Turning to fig. 1E in another embodiment, instead of a web forming device 40 one ormore stitching devices 401 are used. Fig. 1E does not show the conveyor or the depositingstation because these may be the same as shown in the previous examples. Fig. 1E onlyshows an alternative to the web forming device 40. The stitching device(s) 401 may also beused in addition to the web forming device 40. In the shown embodiment, two stitchingdevices 401 are used, one on the left side of the ribbon which is to be formed and one on theright side. Each stitching device 401 comprises a needle insertion device 402 above the fibers14 and a pivotable loop forming device 403 positioned below the fibers. Stitching technologyis known technology by itself, for instance for cloth as will be appreciated by the skilledperson.

Method of producing a ribbon

In use, a method of forming a ribbon comprising bamboo fibers, may comprisepositioning the fibers 14 on the conveyor 16 and conveying the fibers or fibers in the transportdirection T. Next, the fibers are covered with thread 42 of a sticky material by forming thethread with the web forming device 40 which is positioned above the conveyor. The formedthread 42 drops onto the fibers 14 and forms a web 45 which interconnects the fibers into aribbon. The fibers 14 may be aligned as unidirectional fibers on the conveyor, wherein thefibers are oriented at an angle (a) of between 0 and 90 degrees relative to a transportdirection T of the conveyor.

The fibers 14 may be bamboo fibers, but may also be flax fibers or hemp fibers. Thefibers 14 may have a length of between 50 mm and 700mm. If the fibers are short (50mm)and are oriented at an angle of for instance 30 degrees to the transport direction of theconveyor, the produced ribbon 12 may have a width of 25mm (sinus of 30 degrees). If theribbons are long (700mm) and are oriented at an angle of 90 degrees to the transportdirection, the ribbon may have a width of 700mm.

In a splitting step upstream of the ribbon forming device 10, the method maycomprise: supplying bamboo parts 72 to the bamboo splitting device 75 (discussed furtherbelow), splitting the bamboo parts into flat pieces 74, in particular having a thickness (T)of less than 2,5 mm, preferably less than 1 mm, more preferably between 0,3 and0,5 mm, splitting the flat pieces 74 into elongate fibers 14, in particular having a width (W)of less than 2,5 mm, preferably less than 1 mm, more preferably between 0,3 and0,5 mm, andpositioning the fibers 14 onto the conveyor 16.

The fibers 14 may be maintained in position on the conveyor 16 by applying suctionvia the suction holes.

The formed ribbon may be rolled onto itself as a roll, with or without a bobbin.

Turning to fig. 18, this figure shows a variant of the ribbon, but also shows thearrangement in which the fibers may be deposited on the conveyor 16. Since thearrangement of the fibers on the conveyor results in a same arrangement of the fibers in theribbon, this can be shown in a single figure. In this variant the ribbon comprises unidirectionalfibers 14 which are oriented along the main direction of the ribbon 12. The fibers are arrangedin unidirectional bundles 114. Each bundle 114 may comprise fibers 14 having a same lengthand of which the opposite ends of the fibers are also aligned with one another.

In top view, the bundles 114 are arranged in a staggered manner. In a transversedirection 115 of the ribbon, consecutive (i.e. adjoining) bundles 114 are staggered relative toone another in the main direction 116 of the ribbon 12. In other words, one bundle 114A isoffset over a staggering distance 117 along the main direction relative to an adjoining bundle114B.

Furthermore, the bundles 114 may partially overlap one another. In the maindirection, one bundle 114C is partially laid on top of another bundle 114A. A next bundle (inthe main direction) partially overlaps the bundle 114C. In this way, regions of overlap 121 arecreated between the bundles and between the fibers. Hence, the staggered configurationmay occur both in the transverse direction 115 and in a vertical direction 118 of the ribbon.This results in a relatively strong ribbon which can effectively be used for producingcomposite products.

The depositing station 28 may be configured for carrying out the deposition ofbundles of fibers on the conveyor 16 in the manner as described above. A robot arm with agripper may be a suitable device for depositing the fibers in this way, but other methods arereadily conceivable on the basis of the chute as disclosed herein.

Alternatively, the depositing station may deposit individual fibers 14 instead ofbundles which are aligned with the main direction 116 of the ribbon in a staggered manner.The staggered configuration would be the same both in the transverse direction 115 and thevertical direction 116, but instead of staggered bundles 114 individual fibers 15 would bestaggered, both on the conveyor and in the ribbon.

The individual fibers 14 in each bundle may have gaps between them, i.e. they maynot be arranged very dense. This allows the web forming device 40 to - in the regions ofoverlap 121 - form the web 45 on one bundle 114C, wherein the web connects the bundle114C to the bundle 114A which is (partially) underneath it. This creates a ribbon which isstrong enough to be processed in further steps. Instead of for bundles this method may alsobe used with individual fibers which partially overlap one another.

The web forming device also interconnects the adjoining bundles or individualribbons in the transverse direction 115.

Multiple staggering arrangements are possible similar to the arrangement of bricks ina brick wall. For instance the staggering distance 117 may be one half of the length of thefibers, or more, or less. The staggering distance may the same throughout the ribbon or mayvary over the width or length of the ribbon.

Alternative embodiments

Turning to fig. 3, in an alternative embodiment the depositing station 28 may beconfigured for depositing non-aligned fibers 14 onto the conveyor. Such fibers may forinstance be bamboo fibers, flax fibers or hemp fibers. They may have a random direction,sometimes indicated as non-woven in the field of the art. The web forming device 40 forms aweb on the non-aligned bamboo fibers in a same fashion as explained in relation to figures1 A, 1B and 2. The fibers may be deposited on the conveyor 16 with a chute or with a hopperor with one or more conveyors according to the embodiment of fig. 2.

The web forming device 40 may be an electrospinning device.

The ribbon 12 which is formed will comprise bamboo fibers have randomorientations.

The ribbon 12 which is formed may be broader than the ribbon for unidirectionalfibers, and may have a width of up to 2000mm, perhaps even 3000mm.

Turning to fig. 4, in yet another embodiment, the device further comprising a flakecutting station 46 positioned downstream of the web forming device. In this embodiment, theweb forming device 40 may also be an electrospinning device. The flake cutting station maybe configured for cutting the formed ribbon into flakes 50. The flakes may for instance have alength and width of between 5 mm and 200 mm. The flake cutting station may comprisecutting knives 48 for cutting the formed ribbon into longitudinal strips 49. The cutting knivesmay be rotary knives.

Additionally, the flake cutting station may comprise one or more transverse cuttingknives 50 for cutting the strips 49 into flakes. The transverse cutting knives may be positioneddownstream of the cutting knives 49. The transverse cutting knife or knives may be a rotaryknife which travels in a transverse direction across the conveyor or may be a knife or multipleknives, in particular a long knife or long knives, which moves or move downward onto theconveyor and subsequently upwards in a reciprocal cutting motion. Other ways of cutting theribbon into flakes 50 are also possible, for instance with a shredder or puncher.

The flakes may have a square, rectangular, general polygon, circular or oval shapeor have any other suitable shape. The flakes 50 may drop from the downstream end of theconveyor into a collecting device, e.g. a tray or bag. The flakes 50 which are formed will havebamboo fibers having random orientations.

The flakes 50 were found to be very suitable for producing fiber reinforced productsin a further downstream process.

Turning to figures 16 and 17, a further embodiment of the ribbon forming device 10 isshown. The conveyor 16 comprises a belt 18 having projections 125 and/or indentations 126.The ribbon 12 which is formed will be formed with corresponding projections 125 orindentations 126. The projections or indentations may have a shape which is determined bythe required shape of the end product, i.e. the composite product which is to be formed. Morein general, the conveyor had a 3D shape in order to create a 3D ribbon 12.

It is possible to position 3D metal moulds, or any other material plated with aconductive layer, on the conveyer 16. These moulds can be covered with bamboo fibers orflakes made of bamboo ribbon by simply dropping them onto the surface. By applying anelectric charge on the flakes and an opposite charge on the moulds the flakes will be electro-statically attracted by the mould’s surface and form an even layer on its surface. When thislayer of fibers 14 or flakes 50 is covered by an electrospinned web, the fibers or flakes willform a cohesive shape. This shape can be solidified by applying extra electro spun layers orby spraying or brushing a resin over its surface. The shape can also be inserted into a mouldto inject a resin or a thermo-plast against its surface.

In order to achieve a uniform layer on the horizontal surfaces, vertical surfaces andinclined surfaces on the conveyor 16, the electrospinning yarn can be applied by controllablymoving the spinning nozzle in a 2D or 3D motion around the shape, e.g. by a robot-arm.

In order to maintain the fibers or flakes firmly in position on the mould, the total forcecan be increased by providing small suction holes in the moulds in the way this is usuallydone in vacuum forming moulds. In this way, the fibers or flakes are held in place by both anelectrostatic force and by a suction force.

After the forming of the ribbon 12, the ribbon 12 may be cut into flakes 50, whereinone flake 50 comprises a single projection and/or a single indentation, or multiple projectionsand/or multiple indentations. It is noted that the ribbon 12 may also be formed by droppingflakes onto the conveyor. In other words, the ribbon 12 may be formed by flakes and later cutbe cut into flakes again.

Subsequently in the forming of the product, multiple flakes having a same projectionsor indentation may be stacked and impregnated with resin. This may be carried out in amould or on a mandrel or without a mould or mandrel. In this way, a strong fibre reinforcedproduct having multiple layers of flakes 50 may be created.

It will be clear that the projections or indentations may have different sizes and/orshapes.

Method of forming products from the ribbon

With reference to figures 9, 10, 11, 12 and 13, a method of manufacturing a fiberreinforced product 100 from the ribbon 12 may comprise forming the ribbon into pre-definedshape, in particular with a mandrel 101 or mould. Obviously, the ribbon may be cut into smaller pieces which are easier to handle. Mandrels or moulds for fiber reinforced productsare obviously known. The ribbon may subsequently be impregnated with resin and the resinis then hardened, e.g. cured. This results in the product. Multiple layers of ribbon or piecesthereof or multiple layers of flakes may be used in the mould or on the mandrel.

One particular product 100 which may be manufactured with the ribbon is anelongate member, in particular a tubular member, i.e. a pole.

With reference to fig. 9, the pole may be manufactured by winding a ribbon 12 in ahelical manner about a main axis 102 of a product to be formed. A mandrel 101 may be usedas a core. In the embodiment of figure 9, two ribbons 12A, 12B are simultaneously woundaround the core. The ribbons 12A, 12B have fibers 14 which may be unidirectional. The fibersof the first ribbon 12A have a different orientation than the fibers 14 of the second ribbon 12B.The fibers of ribbon 12B are aligned with the axis 102 of the mandrel. The fibers of the firstribbon 12A are not aligned with the axis 102 and are positioned in a helical manner about themandrel.

For the second ribbon 12B the fibers are placed diagonally on the ribbon, i.e. at anangle to the main axis of the ribbon 12B. The second ribbon 12B is wound in a helical mannerand if the pitch angle of the wound ribbon relative to the axis 102 is the same as the angle ofthe fibers 14 relative to the main direction of the ribbon, the fibers 14 are aligned with themain axis 102 of the elongate member, or at least may be oriented at an angle of less than 5degrees relative to the main axis. This results in a very strong and stiff elongate member.The pitch determines the distance in overlap between the layers which are formed and is afactor which determines the strength of the product.

The fibers of the first ribbon 12A are wound in a helical manner around the core. Thisresults in a high torsion stiffness. By combining two layers, the end product becomes strongand stiff.

The resin may be applied during the winding for instance in the “armpit” where theribbon meets the product to be formed. However, other ways of applying the resin are alsopossible, e.g. by spraying the resin onto the ribbon or onto the product 100 during theformation thereof.

Turning to fig. 10, in this embodiment the product 100 is created by winding threeribbons 12A,12B,12C around the mandrel 101 simultaneously. The second ribbon 12B hasfibers 14 which are oriented at an angle to the main direction of the ribbon and is wound at a same pitch angle relative to the main axis 102 of the mandrel, resulting in fibers 14 which arealigned with the main axis 102.

The first ribbon 12A and third ribbon 12C have fibers which are oriented at opposedangles relative to the longitudinal direction of the ribbon. The fibers of the first and third ribbonmay be wound in opposite helical directions onto the mandrel. This results in an evenstronger end product, having a high torsion stiffness in both possible directions of torsionaldeformation and a high bending stiffness as a result of the fibers 14 which are aligned withthe main axis.

Turning to fig. 11, the product 100 is formed by winding a single ribbon 12 aroundthe mandrel. The fibers 14 are oriented at an angle to the main direction 104 of the ribbon.This angle may for instance be 80 degrees, but a different angle is also possible. The ribbon12 is wound at a same or similar pitch angle of about 80 degrees relative to the main axis102 of the mandrel. As a result, the fibers 14 extend parallel to the main axis 102 in the endproduct.

The product 100 of figure 12 is similar to the product of figure 11, with a differencethat the pitch angle of the layers on the product relative to the main axis 102 is smaller, forinstance 70 degrees, and the overlap between the layers on the mandrel is smaller. If thefibers are to extend parallel to the main axis 102 of the mandrel, the fibers should also beoriented at a smaller angle to the main direction 104 of the ribbon, for instance 70 degrees.

Turning to figure 13, a product 100 having only fibers 14 which are oriented parallelto the main axis 102 can also be made by winding multiple ribbons simultaneously.

The elongate member may also be coreless.

Such an elongate member 100 may be used in reinforcing bodies made of soil, earthor landfill, such as a levee, dyke, embankment or similar body. Currently such bodies areoften reinforced with steel members. It was recognized that this is disadvantageous, becausesteel members are not a natural material. Moreover, sometimes further civil engineeringprojects need to be carried out on such land bodies. In such a case it may be required toremove part of the land body or to drill through the land body. If the land body is reinforcedwith steel members this may be very difficult and in case of drilling, the drill may becomedamaged.

It was recognized in the present invention that elongate bodies made from bamboofiber are strong enough to strengthen the land body, but weak enough to be destroyed by anexcavating machine or drilling machine. An ultrasonic or high frequency device may be usedin the destruction or removal of the poles. Furthermore, bamboo fibers are a natural materialand from the viewpoint of environmental friendly engineering elongate members of a naturalmaterial have a preference over steel.

The resin may be a natural (or bio-based) resin, resulting in a fully natural product.For instance, the resin may be made from bamboo leaves and branches. Other types ofnatural resin may be: furan and lignin resins, starch and starch caprolactone blends,polyesters such as poly alkenesuccinates, polyesteramides; polyhydroxy alkanoates such aspolyvinyl butyrate and polyvinylvalerate; and poly α-hydroxy acids such as polylactic acid andpolyglycolic acid. Of these some are biodegradable, including the starch polymers,polyhydroxyalkanoates and polyesteramides.

The ribbon 12 or flakes 50 formed with the present invention can also be used tomake other kinds of composite products. For instance, parts of cars can be made, e.g. thechassis or body parts of cars. The present invention allows most parts of cars which arecurrently made from steel, aluminium or carbon to be made from natural fibers, in particularbamboo. Other kinds of composite products are also possible such as boats, airplanes orframes or other products for various purposes and basically any composite product which iscurrently made from carbon fibers. It is noted that the individual fibers 14 obtained with thepresent invention may also be processed in a different way into a composite product. Prior tothe present invention it was very difficult to obtain suitable bamboo fibers to do this. However,with the present invention a multitude of new applications of bamboo fibers becomespossible. The present invention also enables a multitude of new applications of flax and hempfibers in composite products.

Fiber forming device and method

Turning to figures 5 and 6A, in a further aspect, the present invention further relatesto a fiber forming device 70 for splitting a bamboo part 72 into fibers. The fiber forming device70 may be part of the ribbon forming device 10 and may be positioned upstream of theconveyor 16, but may also be used independently.

The fiber forming device 70 is configured for splitting bamboo parts 72 into flatpieces 74 and subsequently splits the flat pieces 74 into bamboo fibers 14, which may thenbe used in the ribbon forming device 10.

The flat piece 74 will typically be elongate and have a length of at least 0,3 mm to700 mm, preferably 10 mm- 500mm. Multiple flat pieces 74 may be fed to the deviceconsecutively.

The fiber forming device 70 comprises a bamboo part splitting device 75 configuredfor splitting the flat piece 74 of bamboo from the bamboo part 72. The bamboo part splittingdevice 75 comprises: - at least a first rotary member 76 and a second rotary member 77 for guiding thebamboo part 72 between them, - at least one splitting edge 78 positioned downstream from the first and second rollerfor splitting a flat piece of bamboo from the bamboo part, . The bamboo part splitting device 75 may comprise multiple rotary elements in series.The rotary elements 66, 67 may be rollers but may also be rotary tracks.

The splitting edge 78 may be positioned below a trajectory 79 which is followed by thebamboo part, and in this configuration the splitting edge 78 splits the flat piece from a bottomside 180 of the bamboo part.

The splitting edge 78 is configured to “split” instead of to “cut”, allowing the split toextend along the natural direction of the fibers. This is notably different from cutting in whichthe fibers may be damaged by the cutting action. The splitting takes place at a distanceupstream of the splitting edge, for instance about 20-50 mm upstream of the splitting edge,but this difference may vary. To this end the splitting edge may be more blunt than a knife. Inside view an angle of the splitting edge may be greater than 30 degrees.

The splitting edge 78 may be stationary during the splitting of each flat piece 74, andthe position of the splitting edge may be adjustable between splitting operations for controllinga thickness of the flat piece of bamboo which is cut from the bamboo part.

The bamboo part splitting device 75 may comprise a ramp 81 positioned downstreamfrom the first and second rotary member 76, 77 and upstream from the splitting edge 78. Theramp 81 has an upper surface 120 and is configured for bending the bamboo part at thesplitting location, in particular in an upward direction. The upper surface of the ramp mayextend at an angle of 5-10 degrees to the horizontal. The ramp defines the approach path ofthe bamboo part 72 and ensures a constant thickness of the flat piece 74. This improves thesplitting because the flat piece tends to straighten by its own stiffness and tends to split fromthe bamboo part. A gap 69 is defined between a downstream end of the ramp 81 and the splitting edge 78. The flat piece travels through this gap, in particular in a downward direction.The splitting edge 78 itself may have an upper part which is configured to assist in thebending of the bamboo part 72. To this end, the upper part of the splitting edge may follow acurved path defined by the ramp.

An auxiliary rotary member 86 may be positioned vertically above the ramp and/orabove the splitting edge 78 and may be biased by a spring element to push the bamboo partagainst the ramp and/or the splitting edge. This ensures that the bamboo part 72 is bent atthe splitting location and prevents undesired movements of the bamboo part 74 and assists inobtaining the required thickness of the flat piece 74. The auxiliary rotary member 86 may bedriven.

In particular, the bamboo part 74 may be maintained in a bent shape by the rampand/or by the splitting edge and/or by the auxiliary rotary member 86 in a region upstream ofthe splitting location, at the splitting location itself and in a region downstream of the splittinglocation. This improves the splitting action.

The first and second rotary member 76,77 and the splitting edge may form a modularassembly 82 and the bamboo part splitting device may comprise at least two of thesemodular assemblies 82A, 82B in series for successively cutting at least two flat pieces fromthe same bamboo part in a single run of the bamboo part through the bamboo part splittingdevice. The number of modular assemblies 82A, 82B, etc. may be 3, 4, 5 or a greaternumber.

The first rotary member 76 may be an upper rotary member located above thetrajectory followed by the bamboo part, and the second rotary member 77 may be a lowerrotary member positioned below the trajectory followed by the bamboo part. The first andsecond rotary members may have respective horizontal rotation axes 83, 84. The first and/orsecond rotary members 76,77 are driven by a drive (not shown). The first and/or secondrotary members may be biased by a spring element 85 in order to exert a pressure force onthe bamboo element and to clamp the bamboo part between them. The spring elements 85allow bamboo parts 72 of different thickness to be processed in the device. The springelements further create sufficient friction so that the bamboo part is moved in spite of thecounteracting force exerted on the bamboo part 72 by the splitting edge 78.

The first and/or second rotary members 76,77 may be provide with knurling or a layerof friction material such as rubber

The first and/or second rotary members 76, 77 may have a diameter of at least 30mm.

In use, when the bamboo part 72 enters the device, it is pushed towards the firstsplitting edge 78 by a first pair of first and second rotary members 76, 77 which are locatedupstream of the splitting edge. When the leading part of the bamboo part has travelled pastthe first splitting edge 78 and reaches a second pair of first and second rotary members 76,77, it is then gripped by this second pair of first and second rotary members 76, 77. From thispoint onward, the bamboo part 72 is pulled against the splitting edge, not pushed. To this endthe second pair of driven first and second rotary members 76, 77 downstream of eachsplitting edge may rotate slightly faster than the first pair of driven first and second rotarymembers 76, 77 upstream of the splitting edge, and this increase in speed is continued in adownstream direction. In this way, it is ensured that the bamboo part 72 will be pulled, notpushed. The driven first pair of first and second rotary members 76, 77 have a coasting (orfree-wheeling) mode which allows the first pair of driven first and second rotary members 76,77 to rotate faster than the speed determined by the drive.

This configuration may be repeated for subsequent modular assemblies 82A, 82B. Inthis way the bamboo part will be pulled over each cutting edge as soon as it reaches the pairof driven first and second rotary members 76, 77 which is located downstream of the cuttingedge 78 of the respective modular assembly. This improves the splitting in each modularassembly. The drives of the respective pairs of first and second rotary members 76, 77 maybe synchronized to ensure this increasing speed. Alternatively, a single drive may drivemultiple the pairs of driven first and second rotary members 76, 77 and a gear box may beprovided for each pair, wherein the gear boxes have slightly increasing speeds in adownstream direction.

In another, simpler embodiment, the speed of the different pairs of driven first andsecond rotary members 76, 77 may be the same. Although this has a disadvantage that thepulling action is not ensured to the same degree, the drive system can be simpler.

The bamboo part splitting device 75 may be configured to split flat pieces 74 having athickness (T) of less than 1 mm, in particular less than 0,5 mm, from the bamboo part. Thethickness is determined by the geometry of the different part, in particular by the elevation ofthe splitting edge 78 above the upper surface 120 of the ramp at the downstream end of theramp.

With reference to figs. 6A, 7 and 8, the fiber forming device 70 may further comprise aflat piece splitting device 80 for splitting each flat piece 74 into bamboo fibers 14. The flatpiece splitting device 80 may form an integral part of the fiber forming device 70 (see fig. 6A).In a variant, the flat piece splitting device 80 may be separate (see fig. 7). It is noted that fig. 7shows the flat piece splitting device 80 as a separate device but is also intended to show theflat piece splitting device 80 which is integrated in fiber forming device 70 according to fig. 6A.The flat piece splitting device may be positioned below the splitting edge 78 and below atrajectory followed by the flat piece 74.

The flat piece splitting device 80 is configured to split the flat pieces into fibers 14having a width (W) of less than 2,5 mm, preferably less than 1 mm, more preferably between0,3 and 0,5 mm.

The flat piece splitting device 80 for splitting a flat piece 74 of bamboo into a pluralityof fibers 14 may comprise: - a first rotary element 88 configured for rotation about a first axis 90, and - a second rotary element 89 configured for rotation about a second axis 90’.

The first and second rotary members 88, 89 will typically be driven.

The first and second axis 90, 90’ may be parallel. The rotary elements 88, 89 can berollers as shown or can be tracks or a similar device. In case of tracks, each rotary elementwill typically have two rotation axes.

The first rotary element 88 comprises a plurality of first splitting members 91 having afirst diameter (D1) and a plurality of second splitting members 92 having a second, differentdiameter (D2), wherein the first and second splitting members are alternately positioned alongthe first rotation axis 90. The second rotary element 89 comprises a plurality of third splittingmembers 93 having a third diameter (D3) and a plurality of fourth splitting members 94 havinga fourth diameter (D4) which is different from the third diameter, wherein the third and fourthsplitting members are alternately positioned along the second rotation axis 90’, wherein thefirst splitting members 91 are positioned opposite the third splitting members 93 and thesecond splitting members 92 are positioned opposite the fourth splitting members 94. Thecircumferential surface of the first, second, third and fourth splitting members may beprovided with knurling or friction material.

The first and second rotary members 88, 89 are configured to rotate in a direction inwhich the upstream side of the first and second rotary members 88,89 moves toward one another. In this way the flat piece of bamboo 74 is guided into the flat piece splitting device80. A first series of passages 95 are defined between the first and third splitting members 91, 93 and a second series of passages 96 are defined between the second and fourthsplitting members 92, 94, wherein the first series of passages 95 and the second series 96are located at a passage distance 97 (see fig. 8) from one another. The passage distance 97should to be large enough to ensure that the splitting occurs well in advance (or at a sufficientdistance Ds upstream) of the passages, and should be in particular at least 1mm, preferablybetween 1 and 2mm.

The first passages 95 may be positioned in a first straight row, and the secondpassages 96 may be positioned in a second straight row, the first and second row beingpositioned at the passage distance 97.

The first, second third and fourth splitting members 91, 92, 93, 94 may have a widthWm (see fig. 8) of between 0.1 mm and 2 mm, in particular between 0.3 and 1,2 mm. It isnoted that in the figures the widths of the first, second third and fourth splitting members 91, 92, 93, 94 have been exaggerated relative to the diameter, for clarity purposes.

The first, second third and fourth splitting members 91, 92, 93, 94 may have a diskshape. The first and fourth splitting members 91, 94 may have a diameter D1 and the secondand third splitting members 92, 93 may have a diameter D2. A difference in diameter betweenD1 and D2 is preferably at least 1mm. The difference in diameter between D1 and D2 definesthe passage distance 97. Given the required difference in diameter, the diameters D1 and D2may be between 10 mm and 200 mm, preferably 80-150 mm.

The first, second third and fourth splitting members 91, 92, 93, 94 may be mounted onrespective axles 98, 99. The first, second third and fourth splitting members 91, 92, 93, 94may be mounted with interspaces between them as is shown in fig. 8. Alternatively the first,second third and fourth splitting members 91, 92, 93, 94 may be mounted without anyinterspaces, i.e. against one another.

The circumferential surfaces of the first, second third and fourth splitting members 91,92, 93, 94 may be flat, rounded (convex) or concave.

With reference to fig. 7, the fibers which exit the flat piece splitting device aresubstantially parallel (although not exactly parallel) and exit the flat piece splitting device as a group (or bundle) of aligned fibers which are arranged substantially parallel and substantiallyadjacent one another. The fibers have front ends and rear ends which are substantiallyaligned. The fibers may be ready for further processing. The fibers are in particular ready tobe deposited onto the conveyor 16 of the ribbon forming device according to the presentinvention.

Creating the flat pieces of bamboo

With reference to fig. 14, bamboo segments 130 form the base material for thepresent invention. The fiber forming device may comprise an upstream module positionedupstream from the bamboo part splitting device. The upstream module is configured forcreating the flat pieces 74 of bamboo which are fed to the bamboo part splitting device 75from the tubular bamboo segment 130.

The upstream module may comprise a rolling mill for dividing the tubular bamboosegment in an axial direction thereof into multiple tube segments 131. The splitting device ofthe upstream module is configured to split each tube segment 131 into multiple flat pieces 72of bamboo which can be fed to the bamboo part splitting device 75. Such an upstreammodule is known from the prior art and does not form part of the present invention by itself.

Further embodiment of the flat piece splitting device

With reference to figures 6B and 15, in a further embodiment of the invention, the flatpiece splitting device 80 may have a different configuration. Instead of a single pair 110 of afirst rotary element 88 (configured for rotation about a first axis 90) and a second rotaryelement 89 (configured for rotation about a second axis 90’), more than one pair 110A, 110Bis provided and arranged in sequence.

In the first pair 110A, the flat piece 74 of bamboo is split in relatively broad fibers 14’.In the second pair 110B, the relatively broad fibers 14’ are further split into more narrow fibers14.

The first, second, third and fourth splitting member 91, 92, 93, 94 of the first andsecond rotary elements 88, 89 of the first pair 110A are broader than the first, second, thirdand fourth splitting member 91, 92, 93, 94 of the first and second rotary elements 88, 89 ofthe second pair 110B. For instance the first, second, third and fourth splitting member 91, 92,93, 94 of the first and second rotary elements 88, 89 of the first pair 110A may have a widthWm of between 1,2 and 3 mm, whereas the first, second, third and fourth splitting member91, 92, 93, 94 of the first and second rotary elements 88, 89 of the second pair 110B mayhave a width Wm between 0.1 mm and 2 mm, in particular between 0.3 and 1,2 mm. It was found this this multi-step arrangement results in a better reliability and a higher quality of theresulting fibers 14.

The multistep arrangement also allows the fibers 14’ to diverge from one another inthe axial direction of the first and second rotary elements 88, 89. A pair of rollers 122 or guiding tracks or other type of guides may be provided betweenthe first pair 110A and the second pair 11 OB, in order to guide the relatively broad fibers 14’between the first and second rotary elements 88, 89 of the second pair 11 OB. The rollers 122may arrange the fibers in a wider arrangement, i.e. the rollers may increase the distancesbetween the fibers. This improves the splitting action in the second pair 110B.

The rollers 122 may clamp the fibers with a clamping force. The rollers 122 may clampthe fibers and break the wood parts from the fibers. The wood parts let loose from the fibers.In an embodiment, the wood parts can be blown away or sucked away with a blowing deviceor suction device positioned at the rollers 122 or at a position downstream from the rollers122. The fibers may also be combed in a further processing step to remove remaining piecesof wood.

The transport direction T2 through the flat piece splitting device 80 may have adownward component and may in particular be vertically downwards.

The multistep flat piece splitting device 80 may be integrated with the bamboo splittingdevice 75 into an integral fiber forming device 70 as shown in fig. 6B or may be provided as aseparate device.

With reference to fig. 6C, another embodiment of the fiber forming device 70 is shown,in which collector devices 128, in particular collector chutes or channels, are provided. Thechute may be formed by a pipe. An airflow device may be provided for creating an airflow Afin the collector device for transporting the fibers 14.

Each collector device has a collector entry 129 positioned at a downstream end ofeach flat piece splitting device 80. The fibers 14 which exit each flat piece splitting device 80are collected by the collector device and transported further downstream. The collectordevices 128 may work on gravity, possibly in combination with an airflow, but may also be aconveyor. The collector devices may merge at a merge point 131 from where the fibers arefurther conveyed to a storage location or to the ribbon forming device 10.

Alternatively, the merge location 131 may be left out and the collector device maydirectly be connected to the supply tubes 37 shown in fig. 1A.

Method and device of cleaning bamboo fibers

The bamboo fibers 14 which are obtained with the fiber forming device 70 asdescribed above may still have wood parts attached to the fibers. For a high quality fiber, it isdesirable to clean the fibers 14 and remove these wood parts.

Therefore, in an embodiment, a separate processing step of cleaning the fibers maybe desirable. This processing step may form part of the fiber forming device 70 and themethod of using the fiber forming device 70, but may also be carried out separately prior tothe forming of the ribbon or prior to other ways of processing the fibers.

Turning to figs. 19 and 20 a cleaning device 300 for cleaning the fibers 14 maycomprise a gripper 301 configured to hold at least one end 302 of the fibers 14. The fibersmay be held individually. However, it may be preferable to hold a bundle 114 of fibers 14.

The cleaning device 300 may comprise a pair of rotary cleaning members 304, 305which define a passageway 306 between them. The rotary cleaning members 304, 305 aredriven in order to rotate about their respective axes 307, 308. The rotary cleaning members304, 305 are further configured to move relative to the fibers 14 in a cleaning direction 309during the cleaning action and during their rotation. The cleaning direction 309 is away fromthe ends 302 which are held. Either the rotary cleaning members can move or the gripper 301may move, or both. The cleaning direction 309 may be horizontal or vertical or inclined.

The rotary cleaning members 304, 305 may comprise bristles 310 which extendoutwardly from a core 311. The 311 cores define a circumferential surface 320 from which thebristles protrude . Alternatively, the rotary cleaning members 304, 305 may have acircumferential cleaning surface 312, which may be provided with knurling or a skid resistantsurface layer, e.g. a surface layer of rubber or other suitable material.

During the movement in the cleaning direction relative to the fibers, the action of thebristles 310 removes wood pieces 313 which are attached to the fibers 14. The fibers 14become clean and suitable for further processing.

Turning to fig. 20, the direction 314 of the passageway 306, may be oriented at anangle a relative to a straight line between the passageway and the gripper 301. This can bedone by positioning one of the rotary cleaning members forward relative to the other rotary cleaning member and by decreasing a vertical distance 319 between the axes 307, 308 to adistance which is less than the diameters of the cores 311. In this way the fibers 14 are bentduring the cleaning action. This improves the loosening of the wood pieces 313 from thefibers.

Turning to fig. 21, in order to improve the cleaning action of the cleaning device 300and in order to increase the throughput, the cleaning device 300 may comprise multiple pairs321 of rotary cleaning members 304, 305 which may be provided in series and/or in parallel.The cleaning action is improved by providing the pairs 321 in series, and the throughput isincrease by providing the pairs 321 in parallel.

However, a bifurcated cleaning device may also be provided, comprising an entry 322at one pair 321, and wherein one or more branch point 323 is/are provided downstream ofsaid pair. A the branch points, a cleaning trajectory branches in two (and potentially more)separate downstream cleaning trajectories.

Furthermore, the diameters 324 of the rotary cleaning members 304, 305 maydecrease in a downstream direction.

In this configuration, the fibers 14 travel through the cleaning device 300 and are notheld by any gripper. The pairs 321 of rotary cleaning members 304, 305 perform both acleaning action and a holding action. In particular the most upstream pair 321A may rotate ata relatively slow speed, and the subsequent downstream pairs 321B, 321C, etc, may rotate atincreasing speeds to exert a cleaning action in the downstream direction. It will be clear thatthe speed in this context is the speed of the parts of the rotary cleaning members whichengage the fibers. In case of rotary cleaning member without bristles, this may be thecircumferential surfaces 320. In case of rotary cleaning members with bristles, this may bethe speed of the part of the bristles which contact the fibers.

The cleaning action is caused by a frictional engagement of the fibers by the rotarycleaning members 304, 305, either by the bristles or by the circumferential surfaces, or both.

The trajectory defined by the pairs of rotary cleaning members 304, 305 andfollowedby the fibers is not straight but comprises curves. This improves the cleaning action, becausethe wood parts tend to come loose easier when the fibers are bent.

For the configuration of fig. 21, it is also possible that the same angle a is applied.

Turning to fig. 22, a further embodiment of a cleaning device 300 for bamboo fibers isdisclosed, wherein the rotary cleaning members 304, 305 of a single pair 321A have differentdiameters. The rotary cleaning members 304, 305 of a single pair 321A have a samecircumferential speed. This is caused by a common drive belt 325 which engages rotarydriving members 326 on each rotary cleaning members 304, 305.

Preferably, the drive system which drives the rotary cleaning members 304, 305 issynchronized drive system for instance using a single motor and a gear box having aplanetary gear system, a single drive belt or a similar centralized drive system. Obviouslymany variations for the drive system are possible.

As a result, the surfaces 320 of the two rotary cleaning members 304, 305 of a singlepair 321A slip relative to one another. This causes frictional engagement of the fibers 14 andimproves the cleaning action.

Turning to fig. 23, another embodiment of a cleaning device 300 is shown. In thisembodiment, one rotary cleaning member 304 comprises a driven belt 328 supported by afirst and second roller 330,331. The other rotary cleaning member 305 comprises a rotaryflexible member 329, for instance made of rubber. The first rotary cleaning member 304presses into the other rotary cleaning member 305 and forms an indentation therein. Thiscreates a curved trajectory for the fibers 14. The circumferential speeds of the two rotarycleaning members 304, 305 may be the same or be different, in which case slip occurs.

As a result of the curved trajectory, the compressive force and optionally the slip, thewooden parts 313 will be removed from the bamboo fibers 14.

It is noted that the cleaning devices may be incorporated into the flat piece splittingdevice 80 of figures 6B and 15 in the place where the rollers 122 are positioned or may bepositioned downstream of the flat piece splitting device 80 according to any of the precedingembodiments, in order to clean the fibers in a further processing step.

Operation

In operation, the method of splitting a bamboo part into multiple fibers comprises: - inserting a bamboo part 72 into the fiber forming device 70, - splitting a flat piece 74 from the bamboo part, - splitting the flat piece into multiple fibers 14.

The splitting occurs along a direction of the fibers 14 of the bamboo part. This mayoccur both for the step of splitting a flat piece 74 from the bamboo part 72 as for the step ofsplitting the flat piece 74 into fibers 14.

The flat piece 74 which is split from the bamboo part has a thickness of between 0,1and 1 mm, and the flat piece is split in fibers 14 having a width of between 0,1 and 1,2 mm.

During the splitting of the flat piece 74 into fibers 14, each fiber travels through arespective passage 95, 96, and the splitting occurs at a distance Ds upstream of the flat piecesplitting device as a result of the passage distance 97 between the first series of passages 95and the second series of passages 96.

The fibers 14 have a width of between 0.1 and 1 mm, a height of between 0.1 and 1mm and a length of at least 0,5 mm, in particular between 0,5 and 600 mm.

The terms "a" or "an", as used herein, are defined as one or more than one. The termplurality, as used herein, is defined as two or more than two. The term another, as usedherein, is defined as at least a second or more. The terms including and/or having, as usedherein, are defined as comprising i.e., open language, not excluding other elements or steps.

Any reference signs in the claims should not be construed as limiting the scope of theclaims or the invention. It will be recognized that a specific embodiment as claimed may notachieve all of the stated objects.

The mere fact that certain measures are recited in mutually different dependent claimsdoes not indicate that a combination of these measures cannot be used to advantage.

White lines between text paragraphs in the text above indicate that the technicalfeatures presented in the paragraph may be considered independent from technical featuresdiscussed in a preceding paragraph or in a subsequent paragraph.

Claims

A method of producing a belt (12) comprising bamboo fibers (14), the method comprising: positioning the fibers (14) on a conveyor (16) and conveying the fibers in a conveying direction, joining together the fibers (14) by: ° covering the fibers with wire (42) and / or particles of an adhesive material by means of at least one web-forming device (40) that is transported above and / or below the conveyor and that wire and / or ejecting particles, the thread and / or particles formed adhering to the fibers forming a web (45) connecting the fibers to one another to form the band, and / or sewing the fibers together using at least at least one sewing device (40b) adapted to sew the individual fibers together to form the tape.

Method according to claim 1, wherein the fibers are aligned on the conveyor as unidirectional fibers, the fibers being oriented at an angle (a) that is between 0 and 90 degrees with respect to a conveying direction of the conveyor.

Method according to claim 1 or 2, wherein the web-forming device comprises an electro-spinning device, an extruder and / or a spraying device.

Method according to claim 1 or 3, wherein the fibers are non-woven and in particular shorter than 300 mm, wherein the fibers are in particular bamboo fibers, flax fibers or hemp fibers, the method in particular further comprising the step of cutting the formed strip into flakes (50), wherein the flakes in particular have a length and a width that is between 5 and 30 mm.

A method according to any one of the preceding claims, comprising: supplying bamboo parts (72) to a bamboo-forming device (70), splitting the bamboo parts into flat parts (74) having a thickness (T) of less than 2.5 mm, in particular less than 1 mm, more in particular 0.3-0.5 mm, the splitting of the flat parts into elongated bamboo fibers (14) having a width (W) of less than 2.5 mm, in in particular less than 1 mm, more particularly 0.3 - 0.5 mm, and positioning the fibers on the conveyor to form the belt.

The method of the preceding claim, wherein the fiber-forming device (70) is a fiber-forming device (70) according to any of claims 38 to 48.

Method according to any of the preceding claims except claims 5 and 6, wherein the fibers are glass fibers or hemp fibers.

A method according to any one of the preceding claims, wherein the fibers in the bands have a length that is between 10 mm and 700 mm in the case of unidirectional fibers and a length of 5 - 500 mm in the case of non-woven fibers.

A method according to any one of the preceding claims, wherein the conveyor comprises suction holes (21), and wherein the fibers are held in position on the conveyor by applying suction via the suction holes.

Method according to any of the preceding claims except claim 4, wherein the fibers are laid on the conveyor in a staggered manner, and in particular are laid on the conveyor in staggered bundles (114), the fibers or the bundles in particular being top view are arranged relative to each other in a graduated manner across the width of the conveyor, the fibers or bundles being aligned in particular with the main direction (116) of the belt to be formed, and in particular each fiber or each bundle fiber is at least partially under another fiber or bundle of fibers and / or at least partially on top of another fiber or bundle, thus creating overlap areas (121) in the tape.

A method according to any one of the preceding claims, wherein the web is applied: only on one side of the fibers, said side being in particular the upper side, or on both sides of the fibers.

The method of claim 11, wherein a first web is applied to an upper side of the fibers, and thus a band is formed, and wherein the band is subsequently inverted, and wherein a second web is applied to the side of the fibers that previously bottom was, prior to inversion, and then forms the top.

A method according to any one of the preceding claims, wherein the fibers are laid on the conveyor at a depositing station and are deposited in a regulated flow on the conveyor and at a controlled angle with respect to a conveying direction of the conveyor, wherein the depositing station is a buffer device comprising wherein the fibers are released from the buffer device in a controlled manner and laid down on the conveyor, wherein in particular the buffer device comprises a sliding track or a controllable conveyor for depositing the fibers on the conveyor in a controllable manner.

A tape-forming device (10) for forming a tape comprising bamboo fibers (14), the tape-forming device comprising: at least one conveyor (16; 16a, 16b) for conveying the fibers (14) in a conveying direction, a depositing station (28) where fibers are laid on the conveyor, at least one web-forming device (40) which is placed above and / or below the conveyor downstream of the depositing station for covering fibers with thread (42) and / or particles of an adhesive material wherein the thread and / or particles form at least one web (45) interconnecting the fibers into a tape, and / or at least one sewing device (40B) positioned downstream of the depositing station, the at least one least one sewing device is adapted to sew the individual fibers together.

The tape-forming device according to claim 14, wherein the depositing station (28) comprises a positioning device (29) which is adapted to position the fibers on the conveyor as unidirectional fibers and at an angle (a) that is between 0 and 90 degrees with respect to of the transport direction (T) of the conveyor.

A belt-forming device as claimed in claim 14 or 15, wherein the depositing station (28) is arranged for depositing the fibers in a staggered manner on the conveyor, and in particular is arranged for depositing fibers in staggered bundles (114), wherein in plan view the fibers or bundles are particularly arranged with respect to each other in a staggered manner on the conveyor across the width of a conveyor, and wherein the fibers or bundles are in particular aligned with the main direction (116) ) of the tape to be formed, and in particular each fiber or each bundle fiber lying at least partially under another fiber or bundle fiber / or at least partially on top of another fiber or bundle, thus overlapping regions (121) in the band are created.

A belt-forming device according to claim 14 or 16, wherein a depositing station is arranged for depositing non-aligned fibers on the conveyor, the belt of the device further comprising in particular a flake cutting station (46) positioned downstream of the web-forming device, the block cutting station is adapted to cut the formed strip into flakes, wherein the flakes in particular have a length and a width that is between 5 mm and 50 mm.

A belt-forming device according to any of claims 14-17, comprising a fiber-forming device (70) according to any of claims 38-48, which is placed upstream of the conveyor, the positioning device (29) being adapted to receive of the bamboo fibers and placing the bamboo fibers on the conveyor, in particular in a uni-directional manner and at an angle of 10-90 degrees with respect to a conveying direction of the conveyor.

A belt-forming device as claimed in any one of claims 14-18, comprising a rinsing device (56) which is placed at a downstream end of the conveyor and which is adapted to roll up the formed belt in the form of a roll.

A belt-forming device according to any of claims 14-19, wherein the at least one conveyor comprises suction holes (21), and wherein the conveyor further comprises a suction device (22) for applying suction to the fibers via the suction holes to hold the fibers in position on the conveyor by applying suction.

A belt-forming device as claimed in any one of claims 14-19, wherein the at least one conveyor (16; 16a, 16b) comprises a conveyor belt (18) comprising protrusions (125) or reductions (126) for forming a belt with corresponding bulges or reductions.

A tape-forming device according to any of claims 14-21, comprising a first web-forming device (40) for forming a web on one side of the fibers, in particular the top side, and a second web-forming device (40B) for forming a web on the opposite side of the fibers, in particular the lower side.

A tape-forming device according to the preceding claim, adapted to invert the formed tape, wherein the first web-forming device (40) forms a web at the top of the fibers upstream of the inversion and wherein the second-web-forming device forms a web at the top side of the fibers downstream of the inversion of the band, the top side being equal to the bottom side of the band upstream of the inversion.

A tape (12) comprising bamboo fibers (14), wherein the fibers (14) are interconnected by means of thread and / or particles which are interconnected and web-shaped and / or interconnected by means of sewing stitches.

The tape of claim 24, wherein the bamboo fibers are unidirectional fibers and are oriented at an angle that is between 0 and 90 degrees with respect to a longitudinal direction of the tape.

The tape of claim 25, wherein the fibers are arranged in a scraper fashion in the tape, and in particular arranged in scraper bundles (114), the fibers or bundles being arranged in particular in a scraper fashion relative to each other in plan view on the conveyor across the width of the conveyor, with the fibers or bundles being particularly aligned with the main direction (116) of the belt to be formed, and wherein in particular each fiber or bundle fiber is at least partially covered by a another fiber or bundle of fibers and / or at least partially lying on top of another fiber or bundle of fibers, and creating overlap areas (121) in the band.

The tape of claim 24, wherein the bamboo fibers have random orientations.

A tape according to any of claims 24-26, wherein the web (45) is irregular, in particular the thread forming the web is shrunken and extends in random directions and forms many connections to itself or wherein the web is formed by a plurality of interconnected particles that have been arranged in an irregular manner.

29. Tape according to any of claims 24-28, comprising projections and / or indentations.

The roll formed by the belt of any one of claims 24 to 29, wherein the belt is rolled by itself.

A method of manufacturing a fiber-reinforcing product (100) from the tape (12) according to any of claims 24-29 or from the flakes (50) obtained by the method of claim 4 or from the flakes (51) obtained by the apparatus according to claim (17), the method comprising: forming the band (12), a part cut from the band or the flakes (50; 51) in a predetermined shape, in particular by positioning the band , part or flakes on a core or in a mold, impregnating the tape or flakes with resin, allowing the resin to cure.

The method of claim 31, wherein the tape is helically wound around a main axis (102) of a product to be formed.

The method of claim 31 or 32, wherein the fibers are aligned with the major axis, or at least oriented at an angle of less than 5 degrees to the major axis.

A method according to claim 31 or 32, comprising winding a plurality of bands simultaneously, wherein in particular the fibers of one belt are oriented at a different angle with respect to the main axis (102) of a product than the fibers of another belt .

A fiber-reinforced product (100) comprising the band (12) according to any of claims 24-29 and / or flakes (50) obtained with the method according to claim 4 and / or the flakes (51) obtained with the device according to claim 17, wherein the band and / or flakes are / are impregnated with cured resin.

The fiber-reinforced product of claim 35, wherein the fiber-reinforced product comprises an elongate member, in particular a tubular member, comprising a main shaft (102), wherein the tape is helically wound about the main shaft, and wherein at least a portion of the fibers are aligned with the major axis, or are oriented at an angle of less than 5 degrees to the major axis.

Use of the fiber-reinforced product according to claim 35 or 36 for reinforcing a ground body, a body earth or an elevated piece of land, in particular a wall, cunet or embankment, the use comprising introducing the fiber-reinforced product in the body.

A fiber-forming device (70) for splitting a bamboo part into fibers, the fiber-forming device being particularly adapted to be used in the method according to any of claims 1-12 except claim 7 and in the tape-forming device according to a of claims 14-23, wherein the fiber-forming device comprises: a bamboo part-splitting device (75) adapted to split a leaf part (74) of bamboo from a bamboo part (72), wherein the bamboo-part splitting device comprises: ° at least a first rotating member (76) and a second rotating member (77) for guiding the bamboo part therebetween, ° at least one splitting edge (78) which is positioned downstream of the first and second rotating members for splitting a flat part bam -boo of the bamboo part, a flat-part splitting device (80) for splitting each flat part into fibers (14).

The fiber-forming device of claim 38, wherein the splitting edge is positioned under a path followed by the bamboo part, and wherein the splitting edge splits the flat part from a bottom of the bamboo part.

A fiber-forming device according to any of claims 38-39, wherein the splitting edge is arranged to split rather than cut, and wherein the slit is allowed to extend along the natural direction of the fibers, the splitting at a distance upstream of the splitting edge, wherein said distance is in particular at least 10 mm, and wherein a side view is an angle of the splitting edge, in particular at least 30 degrees.

The fiber-forming device according to any of claims 38-40, wherein the bamboo part-splitting device comprises a ramp (81) positioned downstream of the first and second rotating members and upstream of the splitting edge, the ramp being arranged for bending the bamboo part in the location where the splitting takes place, in particular in an upward direction.

A fiber-forming device according to any of claims 38-41, wherein the first and second rotating members and the splitting edge form a modular assembly (82a, 82b, 82c) and wherein the bamboo-splitting device comprises at least two of these assemblies which are arranged in series for successively cutting at least two flat parts of the same bamboo part in a single passage of the bamboo part through the beam-splitting device.

The fiber-forming device according to any of claims 38-42, wherein the passage direction of the bamboo part (72) is substantially horizontal or slightly inclined, the first rotating member being over a path followed by a bamboo part, and wherein the second rotating member is under a path formed, for example, by the bamboo part, and wherein the first and second rotating members have respective horizontal axes of rotation (83, 84).

A fiber-forming device according to any of claims 38-43, wherein the first and second rotating members are driven by a drive.

A fiber-forming device according to any of claims 38-44, comprising at least a first pair of driven first and second rotating members (76, 77) positioned upstream of a splitting edge (78) and a second pair of driven first and second rotating members (76, 77) positioned downstream of the splitting edge (78), the second pair being driven at a higher rotational speed than the first pair, and wherein at least the first pair of first and second rotating members (76) , 77) have a freewheel mode that allows the second pair of driven first and second rotators (76, 77) to pull the bamboo item (72) after the splitting edge at a speed greater than the speed of the first pair of driven first and second rotating members (76, 77).

A fiber-forming device according to any of claims 38-45, wherein a driven or non-driven auxiliary rotating member (86) is positioned vertically above the slope is biased by a biasing element to press the bamboo part (72) against the slope , wherein in particular the top side of the split edge is arranged to cooperate with the slope for bending the bamboo part (72).

A fiber-forming device according to any of claims 38-46, wherein the bamboo part-splitting device is adapted to split flat parts with a thickness (T) of less than 2.5 mm, preferably less than 1 mm, more preferably 0.3-0.5 mm, of the bamboo part, and, wherein the flat part splitting device is arranged to split the flat parts into fibers with a width (W) of less than 2.5 mm, preferably less than 1 mm, more preferably 0.3-0.5 mm.

A fiber-forming device according to any of claims 38-47, wherein the flat-part splitting device is a flat-part splitting device (80) according to any of claims 49-54.

49. Flat part splitting device (80) for splitting a flat part (74) of bamboo in multiple fibers, the flat part splitting device comprising: a first rotating element (88) adapted for rotation about a first axis ( 90), and a second rotating element (89) adapted for rotation about a second axis (91), the first and second axis being parallel to each other, the first rotating element comprising a plurality of first splitting members having a first diameter (D1) and have a plurality of second splitting members having a second, different diameter (D2), the first and second splitting members being alternately positioned along the first axis of rotation, the second rotating element comprising a plurality of third splitting members that are one-third have a diameter and a plurality of fourth splitting members having a fourth diameter other than the third diameter, the third and fourth splitting members being circumferentially positioned along the second axis of rotation, the first, second e, third and fourth splitting members have a splitting surface extending circumferentially, the first splitting members being positioned opposite the third splitting members and with the second splitting members positioned opposite the fourth splitting members, a first series of passages (95) being defined between the first (95) 91) and third splitting channels (93) and a second series of passages (96) are defined between the second (92) and fourth splitting members (94), the first and second series being positioned relative to each other at a passage distance (97) .

The flat-part splitting device (80) according to claim 49, wherein the first passages (95) are positioned in a first straight row, and wherein the second passages (96) are positioned in a second straight row, the first and second row are positioned at passage distance (97) from each other.

The flat-part splitting device according to claim 49 or 50, wherein the first, second, third and fourth splitting members (91, 92, 93, 94) have a width (Wm) that is between 0.1 mm and 2 mm, and in the particularly between 0.1 and 1.2 mm.

The flat-part splitting device according to any of claims 49-51, wherein the first, second, third and fourth splitting members have a disc shape, the passage distance (97) being defined by the difference in diameter between the first and fourth rotating members on the one hand (91, 94) and, on the other hand, the second and third rotary members (92, 93), the passage distance being at least 1 diameter.

The flat-part splitting device of any one of claims 49-52, comprising multiple pairs (110A, 110B) of a first rotating element (88) and a second rotating element (89), the pairs (110A, 110B) being in series are arranged, the first, second, third and fourth splitting members (91, 92, 93, 94) of the second pair having a smaller width (Wm) than the width (Wm) of the first, second, third and fourth splitting members (91 , 92.93, 94) of the first pair.

A flat-part splitting device as claimed in any one of claims 49 to 52, comprising a cleaning device (300) as claimed in any one of claims 60 to 67.

A method of splitting a bamboo part (72) into a plurality of fibers (14), the method comprising: inserting a bamboo part into the fibrous device (70) according to any of claims 38-48, splitting a flat part (74) from the bamboo part (72) with the bamboo part splitting device (75), splitting the flat part (74) into multiple fibers (14) with the flat part splitting device (80).

A method according to claim 55, wherein the splitting takes place according to a direction of the fibers of the bamboo part, both for the step of splitting a flat part of a bamboo part and for the step of splitting the flat part in the fibers.

A method according to claim 55 or 56, wherein the flat part that is split from the bamboo part has a thickness of less than 2.5 mm, preferably less than 1 mm, in particular about 0.5 mm, and wherein the flat part is split into fibers with a width of less than 2.5 mm, preferably less than 1 mm, in particular about 0.5 mm.

A method according to any of claims 55-57, wherein the splitting of the sectional portion into fibers is performed with the flat-section splitting device (80) according to any of claims 49-54, and wherein during splitting of the flat part in fibers, each fiber passes through a respective passage (85), and wherein the splitting takes place at a distance (Ds) upstream of the blade-part splitting device due to the passage distance (97) between the first series passes and the second series passes .

A method according to any of claims 55-58, wherein the fibers have a length of at least 20 mm, in particular between 50 and 600 mm.

A fiber cleaning device (300) for cleaning bamboo fibers (14) comprising: a first rotary cleaner (304) and a second rotary cleaner (305) defining a passage therebetween.

The fiber cleaning device (300) of claim (60) comprising a plurality of pairs (321) of a first rotary cleaner (304) and a second rotary cleaner (305) arranged in series or in parallel.

The fiber cleaning device (300) of claim 60 or 61, wherein a path followed by the fibers as they move through the device comprises at least a first bend where the fibers are bent.

The fiber cleaning device (300) according to any of claims 60-62, wherein the first rotary cleaning member (304) and a second rotary cleaning member (305) comprise: brushes, and / or a peripheral surface (320) that includes knurling or a non-slip surface layer.

The fiber cleaning device (300) according to any of claims 60-63, wherein the first rotary cleaning member (304) and a second rotary cleaning member (305) are driven at a different peripheral speed.

The fiber cleaning device (300) according to any of claims 60-64, wherein pairs of the first rotary cleaner (304) and a second rotary cleaner (305) are arranged in series and are driven at an increasing speed going in the downstream direction, causing sludge between the peripheral surfaces of the first and second rotating members of one pair.

The fiber cleaning device (300) according to any of claims 60-65, comprising at least one gripper for holding the fibers, and wherein the first rotary cleaner (304) and the second rotary cleaner (305) are adapted to move away from the gripper during the cleaning action.

The fiber cleaning device (300) according to any of claims 60-66, comprising the at least one branching point where the path followed by the fibers branches into two or more branches.