Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/04—Arrangements thereof
  • D21F3/045—Arrangements thereof including at least one extended press nip
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23F—COFFEE; TEA; THEIR SUBSTITUTES; MANUFACTURE, PREPARATION, OR INFUSION THEREOF
  • A23F3/00—Tea; Tea substitutes; Preparations thereof
  • A23F3/16—Tea extraction; Tea extracts; Treating tea extract; Making instant tea
  • A23F3/30—Further treatment of dried tea extract; Preparations produced thereby, e.g. instant tea
• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24B—MANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
  • A24B3/00—Preparing tobacco in the factory
  • A24B3/14—Forming reconstituted tobacco products, e.g. wrapper materials, sheets, imitation leaves, rods, cakes; Forms of such products
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/0209—Wet presses with extended press nip
  • D21F3/0218—Shoe presses
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/0209—Wet presses with extended press nip
  • D21F3/0218—Shoe presses
  • D21F3/0227—Belts or sleeves therefor
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/02—Material of vegetable origin

Definitions

• Machine and method for producing a vegetable debris leaf with a pressing unit in the form of a shoe press
• the present invention relates to a machine for manufacturing a leaf based on plant debris such as reconstituted tobacco or reconstituted tea, the machine comprising a feed box-type feed device containing a liquid suspension incorporating fibers based on said plant debris, a scrolling forming fabric on which the feeding device distributes the liquid suspension uniformly over the width of the forming fabric counted perpendicularly to a direction of travel of the forming fabric and configured to ensure drainage of the liquid suspension during its transfer through the forming web until obtaining a wet sheet, a pressing unit in which the wet sheet previously formed on the forming fabric undergoes a pressing action to extract a quantity of water contained in the wet sheet, and a drying unit in which the wet sheet emerging from the pressing unit undergoes a drying action.
• a feed box-type feed device containing a liquid suspension incorporating fibers based on said plant debris
• a scrolling forming fabric on which the feeding device distributes the liquid suspension uniformly over the width of the forming fabric counted perpen
• the invention also relates to a method of manufacturing a leaf based on plant debris, comprising a step of providing such a manufacturing machine.
• cigarette manufacturers value the tobacco waste generated during the manufacture of the cigarettes, by reintegrating them as part of the mixture of the tobaccos constituting the cigarette.
• This tobacco waste is mainly composed of the stems of the tobacco leaf which are not used after the harvest of the leaves, the poor quality leaves, or even tobacco dust of different sizes which are generated during the cutting of the leaves. and during the different stages of manufacturing the cigarette.
• the tobacco waste recycling process essentially comprises the manufacture of a reconstituted tobacco-based sheet.
• the reconstituted tobacco leaf then undergoes a stage of impregnating the sheet, a final drying step of the impregnated sheet and a shredding step, these steps being described later.
• the manufacture of a reconstituted tobacco leaf comprises a step of dispersing the tobacco waste in water, then a spinning and washing step, then a step of pressing the waste to extract a juice from it. fibrous matrix, then a step of refining the fibers, and then a step of diluting the fibers in the water at a concentration of about 1%. This results in the formation of a liquid suspension incorporating recycled tobacco fibers and water.
• the manufacture of the reconstituted tobacco leaf then comprises the following steps. First, the suspension is distributed on a rotating formation web by means of a feed device commonly called "headbox" in the field concerned, which distributes the suspension uniformly over the entire width of the training fabric. at the scroll speed of the latter. The suspension then undergoes a dewatering step on the forming fabric to form a continuous sheet, dry weight of about 65 g / m 2 to a dryness of about 20%. Then, this preformed sheet on the forming fabric is transferred to a pressing unit to increase its dryness to about 40%. Then the sheet thus pressed in the pressing unit is transferred to a drying unit where it undergoes a drying step, typically in a series of steam-heated drying rollers until a dryness of about 80% is reached. .
• a drying unit typically in a series of steam-heated drying rollers until a dryness of about 80% is reached.
• the impregnation stage mentioned above consists of re-impregnating the reconstituted tobacco leaf with the previously extracted juices which have previously been concentrated by evaporation and to which various additives have been added. added to customize the final product.
• the final basis weight is conventionally of the order of 105 g / m 2 .
• shredding consists of cutting the final sheet into shreds for packaging in various containers, for subsequent shipping and transport operations.
• FIG. 1 Another known technique, which is the most widespread currently, corresponds to the use of a manufacturing machine as shown in Figure 1 attached.
• This is a manufacturing machine whose pressing unit 1 is constituted by the arrangement of a rotating drum 2 in the form of a very large cylinder heated by steam under pressure, commonly called “Yankee" in the field concerned.
• the diameter of the drum 2 is very high, of the order of 5 meters.
• the wet sheet then remains in contact with the drum 2, the latter making it possible to initiate the drying of the wet sheet, via the water vapor released, even before the sheet enters the drying unit itself. Then the wet sheet is released at the outlet of the drum 2 for support by the drying unit.
• the pressing action of the wet sheet via the two rollers 6, 7 combined with the drying action suffered by the wet sheet under the effect of the release of steam by the drum 2 allows to achieve the necessary dryness for the sheet which is of the order of 40 to 45%.
• the fact of applying the wet sheet on the Yankee with two pressure rollers 6, 7 providing fairly narrow pressure zones implies that the mass volume of the wet sheet is low, which can be problematic for the operations. later. It is indeed often problematic to redo the leaf to take the desired amount of juice and additives if the fibrous mattress has been too compressed, and sometimes the impregnation is not at the heart of the mattress which also poses a problem of quality (during the impregnation the sheet is colored in dark brown which allows to detect any lack of impregnation).
• the present invention aims to solve all or part of the disadvantages listed above.
• a machine for manufacturing a leaf based on plant debris comprising: a head box-type feed device containing a liquid suspension incorporating base of said plant debris,
• a pressing unit in which the wet sheet previously formed on the forming fabric undergoes a pressing action to extract a quantity of water contained in the wet sheet
• a closed loop-shaped training tape partially arranged between the pressing surface of the pressing shoe and the pressing surface of the counter-press and driven in a scrolling motion by a drive mechanism; pressing being configured so that the wet sheet, driven to scroll under the effect of the movement of movement of the drive belt, is interposed between the drive belt and the bearing surface of the counter-press and is subjected to said pressing action under the effect of the biasing of the pressing surface of the pressing shoe in the direction of the bearing surface of the counter-press by the compression mechanism.
• the operation of such a pressing unit is much safer than the operation of a Yankee, because the user has the opportunity to have spare parts and avoid production stops.
• the technology of the shoe press is proven in terms of reliability and maintenance, it allows producers of such sheets, for example reconstituted tobacco leaves, to eliminate the Yankee post which poses a potential threat of durability of production if damage should occur on this equipment.
• a yankee is subject to binding standards regarding the use of pressure vessels, this aspect is no longer a constraint with the use of a shoe press.
• the presence of a pressing shoe and a counter-press advantageously allows to have a pressure applied to an extended pressure zone, which is ideal for extracting a maximum of water by pressing the structure fibrous.
• This phenomenon is further promoted by the fact that a leaf of plant debris, typically a reconstituted tobacco leaf, naturally has a low tendency to retain water in its fibers, which implies that the pressing efficiency and increased dryness by this technology are optimal.
• the amount of water extracted by the pressing action between the pressing shoe and the counter-press is very high, much higher than that extracted via the two pressure rollers 6, 7 in the case of the Yankee.
• the absence of a drying function within the pressing unit improves safety and is very economical.
• this facilitates the recovery of the juices during the subsequent operation of re-impregnation with the juices previously extracted from the tobacco waste and the additives.
• the shoe press comprises: a moving absorbent strip interposed between the bearing surface of the counter-press and the portion of the wet sheet moving in the gap between the bearing surface of the shoe of pressing and the support surface of the counter-press, at least the face intended to bear against the wet sheet comprises a fiber arrangement creating empty volumes able to absorb a fraction of said extracted water quantity,
• a moving absorbent strip interposed between the moving strip of driving and the portion of the wet sheet moving in the gap between the pressing surface of the pressing shoe and the bearing surface of the counter press, of which at least the face intended to abut against the wet sheet comprises a fiber arrangement creating empty volumes able to absorb a fraction of the said quantity of water extracted.
• the length of the pressing surface of the pressing shoe, counted along the running path of the drive band is greater than 250 mm.
• the pressing shoe and, therefore concomitantly, the counter-press comprise bearing surfaces having such great lengths makes it possible, for the purpose mentioned above, for the pressure zone to have a very large surface, which makes it possible to guarantee that the pressing is effective in order to extract a lot of water under the sole action of pressing but without the mechanical pressure applied to the wet sheet is too high to ensure the maintenance of a mass volume promoting the recovery of the juices and additives during the subsequent re-impregnation operation.
• the compression mechanism can in particular stress the bearing surface of the pressing shoe so that the support surface of the pressing shoe exerts a linear pressure comprised in a range from 600 to 1200 kN per meter width of pressing shoe surface counted perpendicular to the travel path of the drive belt.
• the bearing surface of the counter-press has a shape complementary to the shape of the bearing surface of the pressing shoe. This optimizes the pressing action throughout the period when the wet sheet travels along the length of the pressing surface of the pressing shoe.
• the bearing surface of the counter-press has a convex shape and that the pressing surface of the pressing shoe has a concave shape.
• the shape of the pressing surface of the pressing shoe is a straight cylinder portion whose axis is oriented perpendicularly to the direction in which the support surface of the pressing shoe and the bearing surface of the against -press are facing each other and perpendicular to the running path of the drive band.
• the manufacturing machine comprises a suction transfer unit arranged between the forming fabric and the pressing unit and configured to ensure a transfer of the wet sheet from the forming fabric to the band of drive of the pressing unit.
• the press unit in the form of a shoe press makes it possible to avoid any lack of support of the wet sheet during the transfer within the pressing unit, but this transfer unit comes complete this action by avoiding the absence of support of the wet sheet during its transfer from the forming web to the shoe press, thus limiting the risk of rupture of the wet sheet or lack of separation at the end of the web training.
• the shoe press may comprise a system for injecting a lubricant such as oil, this system being able to form a film with this lubricant between the pressing surface of the pressing shoe and the strip of lubricant. drive, to avoid or limit friction between the drive belt and the support surface of the pressing shoe, for reasons of efficiency and robustness.
• a method of manufacturing a leaf based on plant debris comprising:
• a step of pressing the wet sheet by the shoe press constituting the pressing unit of the manufacturing machine a step in which the pressing unit extracts a quantity of water contained in the wet sheet exclusively under the effect the pressing action applied to the wet sheet by the shoe press and in which the driven wet sheet under the effect of the running movement of the drive band is interposed between the drive belt and the surface pressing against the press and undergoes said pressing action under the effect of the biasing of the pressing surface of the pressing shoe in the direction of the bearing surface of the counter-press by the compression mechanism.
• the plant debris is tobacco debris so that the sheet produced by the manufacturing machine is a reconstituted tobacco leaf.
• the plant debris is tea debris so that the sheet made by the manufacturing machine is a reconstituted tea leaf.
• Figure 1 illustrates, as prior art, the pressing unit in the form of a Yankee of an example of a known manufacturing machine.
• Figure 2 illustrates the pressing unit of an example of a manufacturing machine according to the invention.
• Figure 3 shows the pressing shoe and the counter-pressing used in Figure 2.
• Figure 4 shows the pressing shoe and the compression mechanism used in Figures 2 and 3.
• the invention relates to a machine for manufacturing a leaf based on plant debris.
• the nature of these plant debris is not limiting in itself, but they may preferentially be tobacco debris so that the manufacturing machine relates to the manufacture of a reconstituted tobacco leaf or tea debris so that the manufacturing machine relates to the manufacture of a reconstituted tea leaf.
• the manufacture of a leaf of plant debris is very different from the manufacture of a sheet of paper with regard to the precautions to be taken with regard to the low resistance of plant debris with a basis weight comparable to paper.
• This machine for producing a leaf based on plant debris comprises a feed device (not shown) of the headbox type containing a liquid suspension incorporating fibers based on these plant debris.
• the fibers, and the liquid suspension in general, are typically the result of a step of dispersing tobacco waste from a previous process of manufacturing cigarettes in water. , then a spinning and washing step, then a waste pressing step to extract a juice from the fibrous matrix, then a refining step of the tobacco fibers, then a step of diluting the tobacco fibers in water at a concentration of about 1%.
• the manufacturing machine also comprises a moving forming fabric 10, of which only the exit end is visible in FIG. 2.
• the feeding device distributes the liquid suspension uniformly over the width of the forming fabric 10 (perpendicular to its width). scrolling path).
• the fabric 10 is configured to drain the liquid suspension during its transfer through the forming fabric 10 to obtain a wet sheet denoted "F".
• the section formed by the forming fabric 10 may have any design and organization, non-limiting in themselves provided that they are adapted to the desired function in the particular context of the field of manufacturing of leaf based on plant debris, the properties of such a sheet being quite characteristic compared with that of a sheet of paper; nevertheless, the skilled person is quite able to adapt the training fabric 10 from known techniques.
• the manufacturing machine then comprises a pressing unit 11 visible precisely in Figures 2 to 4 and particularly concerned by the invention.
• the wet sheet F previously formed on the forming fabric 10 undergoes only a pressing action but does not undergo any drying action, unlike the solution of the prior art using a Yankee.
• This pressing action in the pressing unit 11 has the effect of extracting a quantity of water contained in the wet sheet F and increasing the dryness of the wet sheet F during the transfer through and through the unit. pressing 11.
• the manufacturing machine also comprises a suction transfer unit 12 arranged between the forming fabric 10 and the pressing unit 11 and configured to ensure a transfer of the wet sheet F of the forming fabric 10 to a training band 13 of the pressing unit 11, detailed below.
• This transfer unit 12 acting by depression makes it possible to combat the effects of the gravity experienced by the wet sheet F between the forming fabric 10 and the pressing unit 11, limiting the lack of support for the wet sheet F during its transfer. from the forming fabric 10 to the pressing unit 11, thus limiting the risk of rupture of the wet sheet F or lack of separation at the end of the forming fabric 10.
• the presence of this transfer unit 12 remains optional, depending on the needs and properties of the suspension.
• the manufacturing machine finally comprises a drying unit 14 in which the wet sheet F leaving the pressing unit 11 undergoes a drying action.
• the drying unit 14 comprises a succession of drying rollers 15.
• the design and organization of the drying unit 14 are not limiting in themselves and the skilled person is able to adapt these from known techniques.
• the pressing unit 11 extracts the totality of the quantity of water extracted within the pressing unit 11 solely under the effect of the action pressing, without drying action.
• the pressing unit 11 is constituted by a shoe press.
• this shoe press comprises a pressing shoe 19 having a bearing surface 20 and a counter-press 21 having a bearing surface 22 arranged opposite the surface of FIG. pressing 20 of the pressing shoe 19 in a transverse direction Z generally perpendicular to the plane of travel of the wet sheet F between the pressing shoe 19 and the counter press 21.
• the running direction is marked X to understand the path of the wet sheet F during its pressing between the bearing surfaces 20, 22, while the lateral direction Y is the direction jointly perpendicular to the direction X and the direction Z.
• the shoe press comprises a moving strip 18 interposed between the moving strip 13 and the portion of the wet sheet F running in the gap between the bearing surface 20 of the shoe.
• pressing 19 and the bearing surface 22 of the counter press 21 at least the face intended to bear against the wet sheet F comprises an arrangement of fibers creating empty volumes able to absorb a fraction of the amount of water extracted under the pressing action between the pressing shoe 19 and the press drum 24.
• the shoe press comprises a strip 17 absorbent strip interposed between the bearing surface 22 of the counter-press 21 and the portion of the wet sheet F running in the gap between the surface pressing 20 of the pressing shoe 19 and the bearing surface 22 of the counter press 21, at least the face intended to bear against the wet sheet F comprises an arrangement of fibers creating empty volumes able to absorb a fraction of the quantity of water extracted under the pressing action between the pressing shoe 19 and the press drum 24.
• the counter-press 21 comprises a support frame 23 connected to the ground and supporting a press drum 24 in the form of a cylinder, rotatably mounted relative to the support frame 23.
• the surface 22 in practice is constituted at each moment by the portion of the drum 24 located opposite the pressing shoe 19.
• the curvature of the concave bearing surface 20 of the pressing shoe 19 corresponds to the diameter of the convex bearing surface 22 of the counter-press 21 (to the thickness near the absorbent strips 17, 18), which corresponds to the diameter of the press drum 24 used.
• the two bearing surfaces 20, 22 have complementary shapes to ensure a pressing in the continuous Z direction and long wet sheet F during its path in the direction X.
• the shape of the bearing surface 20 of the pressing shoe 19 is a portion of hollow straight cylinder whose axis is oriented in the direction Y.
• the shoe press also comprises a compression mechanism 25 urging the bearing surface 20 of the pressing shoe 19 towards the bearing surface 22 of the counter-press 21.
• the compression mechanism 25 comprises a plurality of hydraulic cylinders staggered along a support beam 26 oriented in the direction Y integral with the frame 23 by means of a spacer system 27.
• the compression mechanism 25 urges the bearing surface 20 of the pressing shoe 19 so that the bearing surface 20 of the pressing shoe 19 exerts a linear pressure in the range of 600 to 1200 kN per meter of width bearing surface 20 of the pressing shoe 19 counted according to its width, that is to say in the direction Y.
• the shoe press comprises a drive band 13 organized in a closed loop partially arranged between the bearing surface 20 of the pressing shoe 19 and the bearing surface 22 of the counter-press 21 and driven in a running movement by a drive mechanism 28.
• the direction of movement of the driving band 13 corresponds to the running direction of the sheet F, represented by the direction X in FIG. 3
• the length L (FIG. 4) of the bearing surface 20 of the pressing shoe 19, counted along the running path of the drive band 13, is greater than 250 mm, or even greater than 300 mm.
• the wet sheet F driven under the effect of the movement of movement of the drive band 13, is interposed between the drive band 13 and the bearing surface 22 of the counter-press 21 and undergoes the action of pressing the shoe 19 against the counter-press 21 under the effect of the biasing of the bearing surface 20 of the pressing shoe 19 towards the bearing surface 22 of the counter-press 21 by the compression mechanism 25.
• the shoe press preferably comprises an injection system
• a lubricant 30 such as oil to form an oil film between the bearing surface 20 of the pressing shoe 19 and the driving band 13, making it possible to avoid or limit the friction between the drive band 13 and the bearing surface 20 of the pressing shoe 19.
• plant debris may be tobacco debris from the prior manufacture of cigarettes or tea debris.
• a use of the manufacturing machine described above may correspond to the implementation of the following method.
• the method of manufacturing a leaf based on plant debris may comprise the following steps: a step of supplying a manufacturing machine as described above, a step of supplying the feeding device of the manufacturing machine with a liquid suspension incorporating fibers based on said plant debris, a step of uniform distribution, by the feed device, of the liquid suspension over the width of the forming fabric 10 counted perpendicularly to the direction of travel of the fabric formation 10, a step of transferring the liquid suspension by the forming fabric 10, together with its dewatering, until obtaining a wet sheet F, a step of pressing the wet sheet F by the shoe press constituent of the pressing unit 11 of the manufacturing machine, a step in which the pressing unit 11 extracts a quantity of water contained in the sheet wet F exclusively under the effect of the pressing action applied to the wet sheet F by the shoe press and wherein the wet sheet F driven to scroll under the effect of the scrolling movement of the drive band 13 is interposed between the drive belt 13 and the bearing surface 22 of the counter-press 21 and undergoes said pressing action under

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• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Polymers & Plastics (AREA)
• Paper (AREA)
• Tea And Coffee (AREA)
• Manufacture Of Tobacco Products (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=59699950

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Citations (5)

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• 2017
  • 2017-07-21 FR FR1756952A patent/FR3069254B1/fr active Active
  • 2017-10-12 CN CN201780094184.4A patent/CN110996689B/zh active Active
  • 2017-10-12 KR KR1020207005132A patent/KR20200033923A/ko not_active Application Discontinuation
  • 2017-10-12 RU RU2020106554A patent/RU2738638C1/ru active
  • 2017-10-12 JP JP2020524686A patent/JP6960054B2/ja active Active
  • 2017-10-12 WO PCT/FR2017/052805 patent/WO2019016432A1/fr active Application Filing

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