CA2496298A1 - Apparatus and process for defibration of bast fiber plants - Google Patents
Apparatus and process for defibration of bast fiber plants Download PDFInfo
- Publication number
- CA2496298A1 CA2496298A1 CA002496298A CA2496298A CA2496298A1 CA 2496298 A1 CA2496298 A1 CA 2496298A1 CA 002496298 A CA002496298 A CA 002496298A CA 2496298 A CA2496298 A CA 2496298A CA 2496298 A1 CA2496298 A1 CA 2496298A1
- Authority
- CA
- Canada
- Prior art keywords
- starting material
- destructurizing
- precomminuted
- plural
- shaft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01B—MECHANICAL TREATMENT OF NATURAL FIBROUS OR FILAMENTARY MATERIAL TO OBTAIN FIBRES OF FILAMENTS, e.g. FOR SPINNING
- D01B1/00—Mechanical separation of fibres from plant material, e.g. seeds, leaves, stalks
- D01B1/10—Separating vegetable fibres from stalks or leaves
- D01B1/14—Breaking or scutching, e.g. of flax; Decorticating
- D01B1/28—Breaking or scutching, e.g. of flax; Decorticating with beaters rotating about an axis perpendicular to the fibre bundle
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Textile Engineering (AREA)
- Crushing And Pulverization Processes (AREA)
- Paper (AREA)
- Debarking, Splitting, And Disintegration Of Timber (AREA)
- Artificial Filaments (AREA)
- Dry Formation Of Fiberboard And The Like (AREA)
- Preliminary Treatment Of Fibers (AREA)
Abstract
The invention concerns a process and apparatus for defibration of bast fiber plants, especially annual plants such as flax, hemp, kenaf, linseed straw and jute, having comminuting means (2) for precomminuting a starting material (1) and having an intermediate store (4) in which the precomminuted starting material (3) is received and from which the precomminuted starting material (3) is dispensed for a metered feed to a downstream processing sector for fiber-extractive destructurization and for separation of fiber fractions and shives. A series arrangement of plural coarse destructurizing means (6,8) and plural fine destructurizing means (7,9,10) is formed along the processing sector which is meteredly fed with the precomminuted starting material (3).
Description
Apparatus and process for defibration of bast fiber lp ants This invention concerns apparatus and a process for defibration of bast fiber plants, especially annual plants, such as flax, hemp, kenaf, linseed straw and jute for example.
Renewable raw materials are becoming ever more popular, since they not only preserve existing resources, but also make a contribution to reduce the greenhouse gas C02. Both the fibrous fractions and the skives, which are the woody fractions of the bast fiber plant stems, are used in different fields of application. Processes and apparatuses have therefore been developed to separate the fibrous fractions and the skives in a starting material. This process of separation is frequently referred to as defibration or decortication.
In defibration/decortication, the starting material is subjected to an operation of fiber-extractive destructurization and subsequently the fibrous fractions and the skives are separated.
The purpose of processing annual plants such as flax or hemp is to use an adapted destructurization process to adapt the property profile of the produced fiber to articles which are later produced using the fibers and to the articles' requirements. It is because of these requirements that destructurization processes have gained importance in recent years that utilize so-called "green" starting materials. The difference to traditional destructurization processes is in the field retting in that the plant after cutting is left on the field only for a few days to dry in order that the residual moisture content of <18~ required for storage may be achieved. In contrast, traditional destructurization processes require starting materials which remain on the field for a prolonged period, during which weathering-based and bacterial effects lead to an embrittlement in order that easier separation of the fiber from the other plant constituents may be achieved through bending/flexing in the course of the fiber-extractive destructization. The plant itself consists predominantly of cellulose, hemicellulose, pectin, lignin, water-soluble substances and also small fatty and waxy fractions.
The fibers of the plant consist of fiber bundles. These bundles differ in length according to fiber variety. In the case of hemp, fiber bundle length is between about 650 mm and about 3500 mm, and in the case of flax it is between about 100 mm and about 1400 mm. The individual fiber in the fiber bundle is glued to the other fibers by pectin. To obtain certain properties for later applications, it is therefore necessary to break down these fiber bundles to a desired level of fineness.
This is significantly more difficult in the case of the green plant, since pectins will have degraded only to a small extent in the course of short field rett. By contrast, however, the high strength properties have remained very substantially intact.
The breakup of the fiber bundles leads to fiber shortening. It must be borne in mind here that the fiber cell of hemp is about 10 mm to about 50 mm in length and that of flax is about 5 mm to about 70 mm in length. Consequently, a higher degree of fiber extraction, and a correspondingly finer fiber, is associated with a degree of shortening which theoretically can take fiber length down to the length of the individual cell.
A high input of energy is required to achieve plant bundle breakup in the case of green starting material.
This is why prior art apparatus for this purpose utilizes high speed assemblies which lead to breakup of the fiber bundles through impinging, bending and shearing stresses. There is a preference for using hammer mills or high speed turbinelike destructurization systems. Fibers from aggressive processing disaggregate from a coarse bast into many individual fibers and fibrils. This leads to clewing and felted structures having a wide scatter of fiber lengths. But such high speed systems lead to the disadvantages described. Moreover, the high energy input takes place in a single stage and the degree of fiber bundle breakup is then influenced by variation of the design of the beating elements and the rotary speed.
EP 0 744 477 B1 describes a process for defibration/
decortication of bast fiber plants wherein the starting material is precomminuted prior to defibration/
decortication such that the starting material is precomminuted into pieces of pour- and/or flowable consistency and these pieces are subsequently defibrated in a high speed rotating mill. The subsequent separation of fibers and shives is effected with the aid of sieves and/or sifters, at which stage the fibers can simultaneously be classified and fractionated according to length and also oversize, dust and foreign bodies can be removed. Defibration is due to the action of impact and/or rubbing and/or shearing in the high speed rotating mills used. The fibers generated with the aid of this process are preferably between 1 mm and 100 mm and especially between 2 mm and 50 mm in length.
DE 199 25 134 A1 describes a process for producing random fiber material from plant parts which comprises a first operating step of removing initially provided harvested material from a stock reservoir stack, a second operating step of forming a strand of material having a predominantly two-dimensional alignment of the plant parts, a third operating step of feeding the strand of material formed into the operational region of a processing station, a fourth operating step of simultaneously comminuting, disaggregating and separating fibers and nonfibrous constituents (skives) and a fifth operating step of separately removing the random fiber material and the nonfibrous plant constituents. There is an option with the known processes of repeatedly performing at least the procedures of destructurizing the plant parts, removing the fractions of material produced and aftertreating the random fiber material. The simultaneous comminution, disaggregation and separation of fibers and skives in a processing station can be repeated by connecting at least two processing stations in series.
The processing stations are equipped with beating tools having blunt hammering surfaces, which serve to incipiently break the plant parts and, to a minor extent, to separate the fibrous fractions from the skives.
The present invention has for its object to provide improved apparatus and an improved process for defibration of bast fiber plants, especially of annual plants, in gentle processing stages but with enhanced efficiency for the separation of fibrous fractions and skives. The present invention further has the purpose to enhance the fraction of fibers and/or skives having predetermined properties for further processing, especially having a predetermined length.
This object is achieved according to the present invention by apparatus according to independent claim 1 and also a process according to independent claim 11.
Apparatus for defibration of bast fiber plants, especially annual plants such as flax, hemp, kenaf, linseed straw and jute, having comminuting means for precomminuting a starting material and having an intermediate store in which the precomminuted starting material is received and from which the precomminuted starting material is dispensed for a metered feed to a _ 5 _ downstream processing sector for fiber-extractive destructurization and for separation of fiber fractions and skives, wherein a series arrangement of plural coarse destructurizing means and plural fine destructurizing means is formed along the processing sector which is meteredly fed with the precomminuted starting material.
The series arrangement of coarsely destructurizing means and finely destructurizing means makes it possible to specifically influence fiber fineness and skive size by subjecting the precomminuted starting material along the processing sector to plural destructurizing procedures, for which coarsely destructurizing means and finely destructurizing means are freely combinable with each other in the series arrangement according to the particular application. A
cascadelike processing procedure where the arrangement of coarsely destructurizing and finely destructurizing means can be adapted to separate fiber fractions and skives having predetermined properties for further processing is made possible.
In an advantageous embodiment of the invention along the processing sector there is an alternating arrangement of one of the plural coarsely destructurizing means and one of the plural finely destructurizing means, whereby an alternating coarse/fine destructurization of the comminuted starting material can be implemented.
Combined with the plural coarsely destructurizing means and the plural finely destructurizing means, sieves and/or sifters can be provided in the series arrangement in one embodiment of the invention for separating fiber fractions and skives along the processing sector and/or at the end of the processing sector. At the same time, in this embodiment, a classification and fractionation of the fiber fractions/shives according to length can take place.
In an advantageous embodiment the plural coarsely destructurizing means each comprise one drum and, disposed in the drum, rotatable beating elements for processing the precomminuted starting material, the rotatable beating elements being arranged on a shaft to be pivotable. The beating elements are turned by means of a shaft in the drum to process the material, and in the course of this turning movement perform pivoting movements due to the pivotable arrangement. The use of such coarsely destructurizing means has the advantage of providing a way to coarsely destructurize the starting material by shearing, rubbing, impact and/or beating that is less costly than known high speed rotating mills, for example hammer mills.
In one embodiment of the invention the rotatably mounted beating elements can be pivotably mounted on a shaft housing and can be pivotable about an axis parallel to the center line of the shaft. This creates beating elements which work like mallets in that they, as the shaft in the drum turns, additionally pivot around an axis formed outside the center line of the shaft and thus act as mallets.
To improve energy input onto the material processed in the coarsely destructurizing means, one embodiment of the invention envisions that the rotatably mounted beating elements are paddle shaped. A particular achievement of this is that the beating and entraining effect exerted by the beating elements on the material to be processed is improved.
In one embodiment of the invention the paddle-shaped beating elements may have at a distal end (distal relative to the shaft) a paddle surface which is curved longitudinally to the shaft and/or transversely to the shaft, whereby a further improvement in the _ 7 _ transportation in the coarsely destructurizing means of the material to be processed is achieved. The paddle surfaces of beating elements can be arranged adjacent to each other in the longitudinal direction of the shaft and offset relative to each other in the circumferential direction of the shaft such that an essentially uninterrupted area is formed were these beating elements to be displaced along a straight line in the longitudinal direction of the shaft. The number and distribution of the beating elements on the shaft can also be chosen such that an essentially uninterrupted area is repeatedly formed. The essentially uninterrupted area optimizes the energy input onto the material to be processed.
The running properties of the coarsely destructurizing means are improved in an advantageous further development of the invention when the rotatably mounted beating elements are arranged on the shaft along one or more spiral lines extending in the longitudinal direction of the shaft. One possibility here is that the rotatably mounted beating elements are positioned essentially along a spiral line extending around the shaft. The beating elements can advantageously each be disposed with a lateral offset to such an orbiting spiral line, so that they are positioned essentially along a spirally orbiting zigzag or curve line. The arrangement along a spiral line prevents a pulsing operation, avoiding higher stress on bearing elements.
It is further ensured thereby that plant material cannot get stuck and that there can be no wraps around the shaft.
The rotatably mounted beating elements may have an outer beating surface having blunt edges. Blunt edges prevent an inadvertent cutting effect when destructurizing the comminuted starting material. In addition, blunt edges improve the impinging effect.
In order that the residence time of the precomminuted starting material in the drum may be increased, which leads to an improved destructurizing and separating effect in the individual coarsely destructurizing means, it is envisaged in one embodiment of the invention that plural impinging elements which extend in the longitudinal direction are arranged on an inner surface of the drum. The impinging elements may be for example angular or u-shaped impinging elements where angled portions project from the inner surface.
The starting material may be precomminuted in the comminuting means into pieces from about 80 mm to about 120 mm, preferably from about 120 mm to about 160 mm and more preferably from about 160 mm to about 200 mm in length. One consequence of this is that the starting material is precomminuted to a desired starting length which in turn significantly influences the length obtained for fiber fractions and skives in the course of the destructurization and separation of these constituents. Precomminution to such lengths, moreover, facilitates automated processing of the precomminuted starting material along the processing sector in the plural coarsely destructurizing means and the plural finely destructurizing means.
An additional benefit of precomminution is that the fiber fractions separated in the course of the processing sector by destructurization of precomminuted starting material have a length and fiber fineness which, when the fiber fractions are used in insulant products, for example insulant panels, provide the thermal conductivity necessary for the insulating effect. The disclosed process for separating the fiber fractions may thus be advantageously used in conjunction with a process for producing an insulant product, especially an insulant panel, such that the separated fiber fractions are mixed with a base material, for example a plastic, and formed into shaped _ g _ articles, in a processing station downstream of the processing sector.
Illustrative embodiments of the invention will now be more particularly by way of example with reference to a drawing where the sole figure shows a schematic depiction of apparatus for defibration of bast fiber plants, especially renewable raw materials.
Referring to the figure, a starting material 1 is fed to a comminuting apparatus 2. The starting material 1 is haulm material of bast fiber plants, such as flax, hemp, kenaf, linseed straw or jute for example. The starting material 1 is preshortened into haulm sections of uniform or approximately uniform length. A thus preshortened starting material 3 then arrives in an intermediate store 4. The starting material 1 is preshortened to a length which is preferably in the range from about 80 mm to about 120 mm, more preferably in the range from about 120 mm to about 160 mm and even more preferably in the range from about 160 mm to about 200 mm and then fed to the intermediate store 4.
From the intermediate store 4, the preshortened starting material 3 can then be metered onto conveying means 5 for feeding the preshortened starting material 3 to a downstream processing sector for destructurizing and for separating fiber fractions and skives. The preshortened starting material 3 is fed via the conveying means 5 to a first dynamic destructurizing unit which is coarse destructurizing means 6 in which the preshortened starting material 3 is subjected to coarse destructurization. A first coarse separation of fibers and skives takes place in this processing stage.
The coarsely destructurizing means 6 comprises a partially open shell surface. The open region of the shell surface has not only an inlet opening for taking in the material to be processed in the coarsely destructurizing means 6 but also an outlet opening for removing the processed material, and this constitutes a simplified engineering construction. The centrifugal force whirls the processed material through the outlet opening onto the conveying means 5, ensuring a constant transportation.
Within the drum-shaped shell surface is disposed a rotor which is advantageously formed to incorporate a shaft and equipped with blunt flat and/or curved beating elements. The number of these beating elements on the rotor is variable. The beating elements are preferably arranged on the rotor along one or more spiral lines extending around the rotor, as individual elements distributed on a rotatable shaft.
The skives separated off are subsequently sieved off via a sieve sector. The coarsely destructurizing means 6 is followed by finely destructurizing means 7 in turn followed by further coarsely destructurizing means 8.
Thereafter, the comminuted starting material 3 is processed in two further finely destructurizing means 9, 10. Along the processing sector, sieves/sifters (not depicted) may be combined with the coarsely destructurizing means 6,8 and the finely destructurizing means 7,9,10 to separate the fiber fractions and skives. The depicted series arrangement of the coarsely destructurizing means 6,8 and the finely destructurizing means 7,9,10 is illustrative.
Depending on the particular application, any combination of the appliances in the series arrangement can be chosen.
The coarsely destructurizing means 6,8 are formed with the aid of a respective dynamic destructurizing appliance which comprises a drum 6a,8a and also beating elements 6b,8b rotatably mounted in the drum 6a,8a. The beating elements 6b,8b are paddle or shovel shaped and mounted on a shaft 11 which serves to rotate the beating elements 6b, 8b in the drum 6a, 8a. The beating elements 6b,8b are pivotably secured to the shaft 11, so that they can perform additional pivoting movements as the shaft 11 turns. In addition, this form of attachment permits quick and economical replacement.
The beating elements 6b,8b are preferably distributed along one or more spiral lines extending in the longitudinal direction of the shaft 11. This makes for a very large operating width, amounting to several meters for example, which permits a high throughput.
Paddle or shovel surfaces for the beating elements 6b,8b are preferably dimensioned such that the paddle or shovel surfaces of beating elements distributed along one or more of the spiral lines around the shaft 11 are arranged adjacent to each another in the longitudinal direction of the shaft 11 and offset relative to each other in the circumferential direction of the shaft, so forming an essentially uninterrupted area were these beating elements to be displaced along a straight line in the longitudinal direction of the shaft 11. The number and distribution of the beating elements 6b,8b on the shaft 11 can also be chosen such that an essentially uninterrupted area is repeatedly formed. The essentially uninterrupted area optimizes the energy input onto the material to be processed.
On an inner surface 6c,8c of the shell surface are arranged plural impinging elements 6d,8d which are preferably formed as profiled retaining strips and serve to lengthen the residence time of the comminuted starting material 3 in the respective drum 6a,8a, to enhance the energy input whereby the defibration/
decortication performed by shearing, rubbing, impinging and/or beating is made more effective. The number and spacing of the impinging elements 6d,8d fixed preferably on the inner surface 6c,8c are variable. The plural impinging elements 6d,8d may be angular or u-shaped elements where angled limbs project from the inner surface 6c,8c. The rotatably mounted beating elements 6b,8b have an outer beating surface having one or more blunt edges.
The finely destructurizing means 7,9,10 each have static and rotating combing elements which are spaced apart and intermesh when the rotating combing elements rotate past the static combing elements.
The destructurizing process described in conjunction with the illustrative embodiment can be summarized as follows. The coarsely destructurizing means 6 provides a first coarse separation of fibers and skives. The shines separated off are subsequently sieved off via a sieve sector (not depicted). Sieve sectors are known as such and therefore are not more particularly described herein. The residual fraction is fed to finely destructurizing means 7. This machine unit comprises comblike segments which are static and rotatory and, by means of intermeshing combing elements, lead to a separation of adherent shines and previously broken up fiber bundles. The detached shines are subsequently sieved off and the remaining material is fed for coarse destructurization to the further coarsely destructurizing means 8, comparable to the coarsely destructurizing means 6. By virtue.of the separation of aliquots (skives) in preceding processing steps, this processing station is fed with a distinctly reduced amount of material, so that the energy input for coarse destructurization is now only applied to the remaining fiber bundles and to the fiber bundles having as yet undetached skives. This is followed by further finely destructurizing means 9 with subsequent sieve sector.
This fiber material is then fed to finely destructurizing means 10 for skives separation.
Following this processing stage, the fibers exhibit a high degree of isolation coupled with a low residual skives content. If necessary, finely destructurizing means 10 can be followed by further downstream finely destructurizing units and/or sieve sectors.
The features of the invention which are disclosed in the preceding description, the claims and the drawing can be significant not only individually but also in any desired combination to actualize the invention in its various embodiments.
List of reference numerals List of reference numerals:
1 Starting material 2 Comminuting means 3 Precomminuted starting material 4 Intermediate store 5 Conveying means 6,8 Coarsely destructurizing means 6a,8a Drum 6b,8b Rotatably mounted beating elements 6c,8c Inner surface of drum 6d,8d Impinging elements 7,9,10 Finely destructurizing means 11 Shaft Claims
Renewable raw materials are becoming ever more popular, since they not only preserve existing resources, but also make a contribution to reduce the greenhouse gas C02. Both the fibrous fractions and the skives, which are the woody fractions of the bast fiber plant stems, are used in different fields of application. Processes and apparatuses have therefore been developed to separate the fibrous fractions and the skives in a starting material. This process of separation is frequently referred to as defibration or decortication.
In defibration/decortication, the starting material is subjected to an operation of fiber-extractive destructurization and subsequently the fibrous fractions and the skives are separated.
The purpose of processing annual plants such as flax or hemp is to use an adapted destructurization process to adapt the property profile of the produced fiber to articles which are later produced using the fibers and to the articles' requirements. It is because of these requirements that destructurization processes have gained importance in recent years that utilize so-called "green" starting materials. The difference to traditional destructurization processes is in the field retting in that the plant after cutting is left on the field only for a few days to dry in order that the residual moisture content of <18~ required for storage may be achieved. In contrast, traditional destructurization processes require starting materials which remain on the field for a prolonged period, during which weathering-based and bacterial effects lead to an embrittlement in order that easier separation of the fiber from the other plant constituents may be achieved through bending/flexing in the course of the fiber-extractive destructization. The plant itself consists predominantly of cellulose, hemicellulose, pectin, lignin, water-soluble substances and also small fatty and waxy fractions.
The fibers of the plant consist of fiber bundles. These bundles differ in length according to fiber variety. In the case of hemp, fiber bundle length is between about 650 mm and about 3500 mm, and in the case of flax it is between about 100 mm and about 1400 mm. The individual fiber in the fiber bundle is glued to the other fibers by pectin. To obtain certain properties for later applications, it is therefore necessary to break down these fiber bundles to a desired level of fineness.
This is significantly more difficult in the case of the green plant, since pectins will have degraded only to a small extent in the course of short field rett. By contrast, however, the high strength properties have remained very substantially intact.
The breakup of the fiber bundles leads to fiber shortening. It must be borne in mind here that the fiber cell of hemp is about 10 mm to about 50 mm in length and that of flax is about 5 mm to about 70 mm in length. Consequently, a higher degree of fiber extraction, and a correspondingly finer fiber, is associated with a degree of shortening which theoretically can take fiber length down to the length of the individual cell.
A high input of energy is required to achieve plant bundle breakup in the case of green starting material.
This is why prior art apparatus for this purpose utilizes high speed assemblies which lead to breakup of the fiber bundles through impinging, bending and shearing stresses. There is a preference for using hammer mills or high speed turbinelike destructurization systems. Fibers from aggressive processing disaggregate from a coarse bast into many individual fibers and fibrils. This leads to clewing and felted structures having a wide scatter of fiber lengths. But such high speed systems lead to the disadvantages described. Moreover, the high energy input takes place in a single stage and the degree of fiber bundle breakup is then influenced by variation of the design of the beating elements and the rotary speed.
EP 0 744 477 B1 describes a process for defibration/
decortication of bast fiber plants wherein the starting material is precomminuted prior to defibration/
decortication such that the starting material is precomminuted into pieces of pour- and/or flowable consistency and these pieces are subsequently defibrated in a high speed rotating mill. The subsequent separation of fibers and shives is effected with the aid of sieves and/or sifters, at which stage the fibers can simultaneously be classified and fractionated according to length and also oversize, dust and foreign bodies can be removed. Defibration is due to the action of impact and/or rubbing and/or shearing in the high speed rotating mills used. The fibers generated with the aid of this process are preferably between 1 mm and 100 mm and especially between 2 mm and 50 mm in length.
DE 199 25 134 A1 describes a process for producing random fiber material from plant parts which comprises a first operating step of removing initially provided harvested material from a stock reservoir stack, a second operating step of forming a strand of material having a predominantly two-dimensional alignment of the plant parts, a third operating step of feeding the strand of material formed into the operational region of a processing station, a fourth operating step of simultaneously comminuting, disaggregating and separating fibers and nonfibrous constituents (skives) and a fifth operating step of separately removing the random fiber material and the nonfibrous plant constituents. There is an option with the known processes of repeatedly performing at least the procedures of destructurizing the plant parts, removing the fractions of material produced and aftertreating the random fiber material. The simultaneous comminution, disaggregation and separation of fibers and skives in a processing station can be repeated by connecting at least two processing stations in series.
The processing stations are equipped with beating tools having blunt hammering surfaces, which serve to incipiently break the plant parts and, to a minor extent, to separate the fibrous fractions from the skives.
The present invention has for its object to provide improved apparatus and an improved process for defibration of bast fiber plants, especially of annual plants, in gentle processing stages but with enhanced efficiency for the separation of fibrous fractions and skives. The present invention further has the purpose to enhance the fraction of fibers and/or skives having predetermined properties for further processing, especially having a predetermined length.
This object is achieved according to the present invention by apparatus according to independent claim 1 and also a process according to independent claim 11.
Apparatus for defibration of bast fiber plants, especially annual plants such as flax, hemp, kenaf, linseed straw and jute, having comminuting means for precomminuting a starting material and having an intermediate store in which the precomminuted starting material is received and from which the precomminuted starting material is dispensed for a metered feed to a _ 5 _ downstream processing sector for fiber-extractive destructurization and for separation of fiber fractions and skives, wherein a series arrangement of plural coarse destructurizing means and plural fine destructurizing means is formed along the processing sector which is meteredly fed with the precomminuted starting material.
The series arrangement of coarsely destructurizing means and finely destructurizing means makes it possible to specifically influence fiber fineness and skive size by subjecting the precomminuted starting material along the processing sector to plural destructurizing procedures, for which coarsely destructurizing means and finely destructurizing means are freely combinable with each other in the series arrangement according to the particular application. A
cascadelike processing procedure where the arrangement of coarsely destructurizing and finely destructurizing means can be adapted to separate fiber fractions and skives having predetermined properties for further processing is made possible.
In an advantageous embodiment of the invention along the processing sector there is an alternating arrangement of one of the plural coarsely destructurizing means and one of the plural finely destructurizing means, whereby an alternating coarse/fine destructurization of the comminuted starting material can be implemented.
Combined with the plural coarsely destructurizing means and the plural finely destructurizing means, sieves and/or sifters can be provided in the series arrangement in one embodiment of the invention for separating fiber fractions and skives along the processing sector and/or at the end of the processing sector. At the same time, in this embodiment, a classification and fractionation of the fiber fractions/shives according to length can take place.
In an advantageous embodiment the plural coarsely destructurizing means each comprise one drum and, disposed in the drum, rotatable beating elements for processing the precomminuted starting material, the rotatable beating elements being arranged on a shaft to be pivotable. The beating elements are turned by means of a shaft in the drum to process the material, and in the course of this turning movement perform pivoting movements due to the pivotable arrangement. The use of such coarsely destructurizing means has the advantage of providing a way to coarsely destructurize the starting material by shearing, rubbing, impact and/or beating that is less costly than known high speed rotating mills, for example hammer mills.
In one embodiment of the invention the rotatably mounted beating elements can be pivotably mounted on a shaft housing and can be pivotable about an axis parallel to the center line of the shaft. This creates beating elements which work like mallets in that they, as the shaft in the drum turns, additionally pivot around an axis formed outside the center line of the shaft and thus act as mallets.
To improve energy input onto the material processed in the coarsely destructurizing means, one embodiment of the invention envisions that the rotatably mounted beating elements are paddle shaped. A particular achievement of this is that the beating and entraining effect exerted by the beating elements on the material to be processed is improved.
In one embodiment of the invention the paddle-shaped beating elements may have at a distal end (distal relative to the shaft) a paddle surface which is curved longitudinally to the shaft and/or transversely to the shaft, whereby a further improvement in the _ 7 _ transportation in the coarsely destructurizing means of the material to be processed is achieved. The paddle surfaces of beating elements can be arranged adjacent to each other in the longitudinal direction of the shaft and offset relative to each other in the circumferential direction of the shaft such that an essentially uninterrupted area is formed were these beating elements to be displaced along a straight line in the longitudinal direction of the shaft. The number and distribution of the beating elements on the shaft can also be chosen such that an essentially uninterrupted area is repeatedly formed. The essentially uninterrupted area optimizes the energy input onto the material to be processed.
The running properties of the coarsely destructurizing means are improved in an advantageous further development of the invention when the rotatably mounted beating elements are arranged on the shaft along one or more spiral lines extending in the longitudinal direction of the shaft. One possibility here is that the rotatably mounted beating elements are positioned essentially along a spiral line extending around the shaft. The beating elements can advantageously each be disposed with a lateral offset to such an orbiting spiral line, so that they are positioned essentially along a spirally orbiting zigzag or curve line. The arrangement along a spiral line prevents a pulsing operation, avoiding higher stress on bearing elements.
It is further ensured thereby that plant material cannot get stuck and that there can be no wraps around the shaft.
The rotatably mounted beating elements may have an outer beating surface having blunt edges. Blunt edges prevent an inadvertent cutting effect when destructurizing the comminuted starting material. In addition, blunt edges improve the impinging effect.
In order that the residence time of the precomminuted starting material in the drum may be increased, which leads to an improved destructurizing and separating effect in the individual coarsely destructurizing means, it is envisaged in one embodiment of the invention that plural impinging elements which extend in the longitudinal direction are arranged on an inner surface of the drum. The impinging elements may be for example angular or u-shaped impinging elements where angled portions project from the inner surface.
The starting material may be precomminuted in the comminuting means into pieces from about 80 mm to about 120 mm, preferably from about 120 mm to about 160 mm and more preferably from about 160 mm to about 200 mm in length. One consequence of this is that the starting material is precomminuted to a desired starting length which in turn significantly influences the length obtained for fiber fractions and skives in the course of the destructurization and separation of these constituents. Precomminution to such lengths, moreover, facilitates automated processing of the precomminuted starting material along the processing sector in the plural coarsely destructurizing means and the plural finely destructurizing means.
An additional benefit of precomminution is that the fiber fractions separated in the course of the processing sector by destructurization of precomminuted starting material have a length and fiber fineness which, when the fiber fractions are used in insulant products, for example insulant panels, provide the thermal conductivity necessary for the insulating effect. The disclosed process for separating the fiber fractions may thus be advantageously used in conjunction with a process for producing an insulant product, especially an insulant panel, such that the separated fiber fractions are mixed with a base material, for example a plastic, and formed into shaped _ g _ articles, in a processing station downstream of the processing sector.
Illustrative embodiments of the invention will now be more particularly by way of example with reference to a drawing where the sole figure shows a schematic depiction of apparatus for defibration of bast fiber plants, especially renewable raw materials.
Referring to the figure, a starting material 1 is fed to a comminuting apparatus 2. The starting material 1 is haulm material of bast fiber plants, such as flax, hemp, kenaf, linseed straw or jute for example. The starting material 1 is preshortened into haulm sections of uniform or approximately uniform length. A thus preshortened starting material 3 then arrives in an intermediate store 4. The starting material 1 is preshortened to a length which is preferably in the range from about 80 mm to about 120 mm, more preferably in the range from about 120 mm to about 160 mm and even more preferably in the range from about 160 mm to about 200 mm and then fed to the intermediate store 4.
From the intermediate store 4, the preshortened starting material 3 can then be metered onto conveying means 5 for feeding the preshortened starting material 3 to a downstream processing sector for destructurizing and for separating fiber fractions and skives. The preshortened starting material 3 is fed via the conveying means 5 to a first dynamic destructurizing unit which is coarse destructurizing means 6 in which the preshortened starting material 3 is subjected to coarse destructurization. A first coarse separation of fibers and skives takes place in this processing stage.
The coarsely destructurizing means 6 comprises a partially open shell surface. The open region of the shell surface has not only an inlet opening for taking in the material to be processed in the coarsely destructurizing means 6 but also an outlet opening for removing the processed material, and this constitutes a simplified engineering construction. The centrifugal force whirls the processed material through the outlet opening onto the conveying means 5, ensuring a constant transportation.
Within the drum-shaped shell surface is disposed a rotor which is advantageously formed to incorporate a shaft and equipped with blunt flat and/or curved beating elements. The number of these beating elements on the rotor is variable. The beating elements are preferably arranged on the rotor along one or more spiral lines extending around the rotor, as individual elements distributed on a rotatable shaft.
The skives separated off are subsequently sieved off via a sieve sector. The coarsely destructurizing means 6 is followed by finely destructurizing means 7 in turn followed by further coarsely destructurizing means 8.
Thereafter, the comminuted starting material 3 is processed in two further finely destructurizing means 9, 10. Along the processing sector, sieves/sifters (not depicted) may be combined with the coarsely destructurizing means 6,8 and the finely destructurizing means 7,9,10 to separate the fiber fractions and skives. The depicted series arrangement of the coarsely destructurizing means 6,8 and the finely destructurizing means 7,9,10 is illustrative.
Depending on the particular application, any combination of the appliances in the series arrangement can be chosen.
The coarsely destructurizing means 6,8 are formed with the aid of a respective dynamic destructurizing appliance which comprises a drum 6a,8a and also beating elements 6b,8b rotatably mounted in the drum 6a,8a. The beating elements 6b,8b are paddle or shovel shaped and mounted on a shaft 11 which serves to rotate the beating elements 6b, 8b in the drum 6a, 8a. The beating elements 6b,8b are pivotably secured to the shaft 11, so that they can perform additional pivoting movements as the shaft 11 turns. In addition, this form of attachment permits quick and economical replacement.
The beating elements 6b,8b are preferably distributed along one or more spiral lines extending in the longitudinal direction of the shaft 11. This makes for a very large operating width, amounting to several meters for example, which permits a high throughput.
Paddle or shovel surfaces for the beating elements 6b,8b are preferably dimensioned such that the paddle or shovel surfaces of beating elements distributed along one or more of the spiral lines around the shaft 11 are arranged adjacent to each another in the longitudinal direction of the shaft 11 and offset relative to each other in the circumferential direction of the shaft, so forming an essentially uninterrupted area were these beating elements to be displaced along a straight line in the longitudinal direction of the shaft 11. The number and distribution of the beating elements 6b,8b on the shaft 11 can also be chosen such that an essentially uninterrupted area is repeatedly formed. The essentially uninterrupted area optimizes the energy input onto the material to be processed.
On an inner surface 6c,8c of the shell surface are arranged plural impinging elements 6d,8d which are preferably formed as profiled retaining strips and serve to lengthen the residence time of the comminuted starting material 3 in the respective drum 6a,8a, to enhance the energy input whereby the defibration/
decortication performed by shearing, rubbing, impinging and/or beating is made more effective. The number and spacing of the impinging elements 6d,8d fixed preferably on the inner surface 6c,8c are variable. The plural impinging elements 6d,8d may be angular or u-shaped elements where angled limbs project from the inner surface 6c,8c. The rotatably mounted beating elements 6b,8b have an outer beating surface having one or more blunt edges.
The finely destructurizing means 7,9,10 each have static and rotating combing elements which are spaced apart and intermesh when the rotating combing elements rotate past the static combing elements.
The destructurizing process described in conjunction with the illustrative embodiment can be summarized as follows. The coarsely destructurizing means 6 provides a first coarse separation of fibers and skives. The shines separated off are subsequently sieved off via a sieve sector (not depicted). Sieve sectors are known as such and therefore are not more particularly described herein. The residual fraction is fed to finely destructurizing means 7. This machine unit comprises comblike segments which are static and rotatory and, by means of intermeshing combing elements, lead to a separation of adherent shines and previously broken up fiber bundles. The detached shines are subsequently sieved off and the remaining material is fed for coarse destructurization to the further coarsely destructurizing means 8, comparable to the coarsely destructurizing means 6. By virtue.of the separation of aliquots (skives) in preceding processing steps, this processing station is fed with a distinctly reduced amount of material, so that the energy input for coarse destructurization is now only applied to the remaining fiber bundles and to the fiber bundles having as yet undetached skives. This is followed by further finely destructurizing means 9 with subsequent sieve sector.
This fiber material is then fed to finely destructurizing means 10 for skives separation.
Following this processing stage, the fibers exhibit a high degree of isolation coupled with a low residual skives content. If necessary, finely destructurizing means 10 can be followed by further downstream finely destructurizing units and/or sieve sectors.
The features of the invention which are disclosed in the preceding description, the claims and the drawing can be significant not only individually but also in any desired combination to actualize the invention in its various embodiments.
List of reference numerals List of reference numerals:
1 Starting material 2 Comminuting means 3 Precomminuted starting material 4 Intermediate store 5 Conveying means 6,8 Coarsely destructurizing means 6a,8a Drum 6b,8b Rotatably mounted beating elements 6c,8c Inner surface of drum 6d,8d Impinging elements 7,9,10 Finely destructurizing means 11 Shaft Claims
Claims (18)
1. Apparatus for defibration of bast fiber plants, especially annual plants such as flax, hemp, kenaf, linseed straw and jute, having comminuting means (2) for precomminuting a starting material (1) and having an intermediate store (4) in which the precomminuted starting material (3) is received and from which the precomminuted starting material (3) is dispensed for a metered feed to a downstream processing sector for fiber-extractive destructurization and for separation of fiber fractions and shives, characterized in that a series arrangement of plural coarse destructurizing means (6,8) and plural fine destructurizing means (7,9,10) is formed along the processing sector which is meteredly fed with the precomminuted starting material (3).
2. The apparatus according to claim 1 which is characterized in that along the processing sector there is an alternating arrangement of one of the plural coarsely destructurizing means (6,8) and one of the plural finely destructurizing means (7, 9, 10).
3. The apparatus according to claim 1 or 2 which is characterized in that sieves and/or sifters are provided along the processing sector.
4. The apparatus according to any one of the preceding claims which is characterized in that the plural coarsely destructurizing means (6,8) each comprise one drum (6a,8a) and, disposed in the drum (6a,8a), rotatable beating elements (6b,8b) for processing the precomminuted starting material (3), the rotatable beating elements (6b,8b) being arranged on a shaft (11) to be pivotable.
5. The apparatus according to claim 4 which is characterized in that the rotatably mounted beating elements (6b,8b) are pivotably mounted on a shaft housing and are pivotable about an axis parallel to the center line of the shaft (11).
6. The apparatus according to claim 4 or 5 which is characterized in that the rotatably mounted beating elements (6b,8b) are paddle shaped.
7. The apparatus according to claim 6 which is characterized in that the paddle-shaped beating elements (6b,8b) have at a distal end (distal relative to the shaft (11)) a paddle surface which is curved longitudinally to the shaft (11) and/or transversely to the shaft (11).
8. The apparatus according to any one of claims 4 to 8 which is characterized in that the rotatably mounted beating elements (6b,8b) are arranged on the shaft (11) along one or more spiral lines extending in the longitudinal direction of the shaft (11).
9. The apparatus according to any one of claims 4 to 8 which is characterized in that the rotatably mounted beating elements (6b,8b) have an outer beating surface having blunt edges.
10. The apparatus according to any one of claims 4 to 9 which is characterized in that plural impinging elements (6d,8d) which extend in the longitudinal direction are arranged on an inner surface (6c,8c) of the drum (6a,8a).
11. A process for defibration of bast fiber plants, especially annual plants such as flax, hemp, kenaf, linseed straw and jute, wherein a starting material (1) is precomminuted in comminuting means (2) and wherein the precomminuted starting material (3) is received in an intermediate store (4), fed from the intermediate store (4) to a downstream processing sector and processed along the processing sector for fiber-extractive destructurization and for separation of fiber fractions and shives, characterized in that the precomminuted starting material (3) is processed along the processing sector in a series arrangement of plural coarsely destructurizing means (6,8) and plural finely destructurizing means (7, 9, 10).
12. The process according to claim 11 which is characterized in that the starting material (1) is precomminuted in the comminuting means (2) into pieces about 80 mm to about 120 mm in length.
13. The process according to claim 11 which is characterized in that the starting material (1) is precomminuted in the comminuting means (2) into pieces about 120 mm to about 160 mm in length.
14. The process according to claim 11 which is characterized in that the starting material (1) is precomminuted in the comminuting means (2) into pieces about 160 mm to about 200 mm in length.
15. The process according to any one of claims 11 to 14 which is characterized in that the fiber fractions and the skives are separated by sieving and/or sifting along the processing sector.
16. The process according to any one of claims 11 to 15 which is characterized in that the plural coarsely destructurizing means (6,8) each comprise one drum (6a,8a) and, disposed in the drum (6a,8a), rotatable beating elements (6b,8b) for processing the precomminuted starting material (3), the rotatable beating elements (6b,8b) being arranged on a shaft (11) to be pivotable.
17. The process according to claim 16 which is characterized in that the comminuted starting material (3) is processed in the drum (6a,8a) by means of an outer beating surface belonging to the beating elements (6b,8b), blunt edges being formed in the region of the outer beating surface.
18. The process according to claim 16 or 17 which is characterized in that the precomminuted starting material (3) is flung in the drum (6a,8a) against plural impinging elements (6d,8d) which extend in the longitudinal direction and which are arranged on an inner surface (6c,8c) of the drum (6a,8a).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP04020221.0 | 2004-08-26 | ||
| EP04020221A EP1630264B1 (en) | 2004-08-26 | 2004-08-26 | Device and method for defibrating bast fibre plants |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2496298A1 true CA2496298A1 (en) | 2006-02-26 |
Family
ID=34926305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002496298A Abandoned CA2496298A1 (en) | 2004-08-26 | 2005-02-07 | Apparatus and process for defibration of bast fiber plants |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP1630264B1 (en) |
| CN (1) | CN1740410B (en) |
| AT (1) | ATE374849T1 (en) |
| CA (1) | CA2496298A1 (en) |
| DE (1) | DE502004005145D1 (en) |
| ZA (1) | ZA200500225B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2485223C2 (en) * | 2007-05-23 | 2013-06-20 | Альберта Инновейтс - Текнолоджи Фьючерз | Method of decortication |
| CN102978715B (en) * | 2012-12-11 | 2015-01-14 | 海南大学 | Extraction machine for field handling of banana stalk fiber |
| CN103061175B (en) * | 2012-12-21 | 2015-05-20 | 新疆博湖苇业股份有限公司 | Reed pulping and preparing device and usage method thereof |
| CN113501354B (en) * | 2021-08-04 | 2022-08-09 | 中国水产科学研究院渔业机械仪器研究所 | Even release of bale breaking before kelp is floated and scalds |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1066514A (en) * | 1951-11-19 | 1954-06-08 | Machine for treating and scutching fibrous stems | |
| FR1322981A (en) * | 1962-02-22 | 1963-04-05 | Bessonneau Ets | New process for preparing bast fibers, in particular hemp and flax |
| CN1003083B (en) * | 1987-06-03 | 1989-01-18 | 湖北省纺织工业科学研究所 | Ramie fibre separator |
| DE3815771A1 (en) * | 1988-05-09 | 1989-11-23 | Claas Saulgau Gmbh | Treatment machine for fibrous plants |
| CN2089937U (en) * | 1990-12-30 | 1991-12-04 | 山东省聊城地区农机研究所 | Peeler for plant bast |
| DE4119749A1 (en) * | 1991-06-15 | 1992-12-17 | Claas Ohg | METHOD FOR REMOVING FLAX AND FLAT PREPARATION MACHINE FOR CARRYING OUT THIS METHOD |
| US5507074A (en) * | 1995-02-24 | 1996-04-16 | Mississippi State University | Decorticating method for separating bast from core of forage chopped kenaf or the like |
| DE19518188C2 (en) * | 1995-05-21 | 1998-06-10 | Rolf Dr Hesch | Process for fiber removal or de-wooding of bast fiber plants |
-
2004
- 2004-08-26 DE DE502004005145T patent/DE502004005145D1/en not_active Expired - Fee Related
- 2004-08-26 EP EP04020221A patent/EP1630264B1/en not_active Not-in-force
- 2004-08-26 AT AT04020221T patent/ATE374849T1/en not_active IP Right Cessation
-
2005
- 2005-01-11 ZA ZA200500225A patent/ZA200500225B/en unknown
- 2005-02-07 CA CA002496298A patent/CA2496298A1/en not_active Abandoned
- 2005-08-26 CN CN200510092302.7A patent/CN1740410B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| ZA200500225B (en) | 2005-07-11 |
| CN1740410A (en) | 2006-03-01 |
| EP1630264A1 (en) | 2006-03-01 |
| CN1740410B (en) | 2010-07-21 |
| DE502004005145D1 (en) | 2007-11-15 |
| EP1630264B1 (en) | 2007-10-03 |
| ATE374849T1 (en) | 2007-10-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0744477B1 (en) | Method for the defibration respectively decorticating of bast fiber plants | |
| CN101688328B (en) | Decortication process | |
| JP5632151B2 (en) | Arundo Donax pulp, paper products, and particleboard | |
| Akin et al. | Pilot plant for processing flax fiber | |
| EP2788544B2 (en) | Method for treating waste paper | |
| US20130221140A1 (en) | Method for processing biomass | |
| CA2496298A1 (en) | Apparatus and process for defibration of bast fiber plants | |
| CN111590711A (en) | Method for processing fiberboard and crushing and sorting device used for same | |
| Munder et al. | Processing of bast fiber plants for industrial application | |
| US6719225B1 (en) | Device and method for pre-disintegrating and cutting into sections fibrous plants and for the separation of fibers and woody parts | |
| EP0122769A2 (en) | Separation of fibres from vegetable matter | |
| JP2008229933A (en) | Bamboo fiber extracting method | |
| CN100402740C (en) | Method for feed preparation of grass pulping raw material by using rigid hammer crusher | |
| WO2014166797A2 (en) | Method and device for comminuting | |
| Baker et al. | Hemp fibre decortications using a planetary ball mill | |
| WO2012115526A1 (en) | Improved method of producing pulp from pinus radiata | |
| Pecenka et al. | Optimal plant lay-out for profitable bast fibre production in Europe with a novel processing technology | |
| Baker | Evaluation of a hammer mill and planetary ball mill for hemp fibre decortication | |
| Niro et al. | Evaluation of a Modified Coconut Husk Decorticating Machine | |
| CN118265684A (en) | Method and apparatus for producing moldable cellulose fiber material | |
| AUTHORITY | UPGRADATION OF QUALITY OF BAGASSE THROUGH ADVANCE DEPITHING PROCESS SUBMITTED | |
| GB2371813A (en) | Bast fibre separation | |
| WO2002008501A1 (en) | Method of mechanical separation of natural fibers | |
| Rodd’s Brudenell River Resort et al. | Fibre characteristics of hemp decortication using a planetary mono mill | |
| PL113911B1 (en) | Centrifugal defibrator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |