Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B50/00—Making rigid or semi-rigid containers, e.g. boxes or cartons
  • B31B50/59—Shaping sheet material under pressure
  • B31B50/592—Shaping sheet material under pressure using punches or dies
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B50/00—Making rigid or semi-rigid containers, e.g. boxes or cartons
  • B31B50/74—Auxiliary operations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F—MECHANICAL WORKING OR DEFORMATION OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F1/00—Mechanical deformation without removing material, e.g. in combination with laminating
  • B31F1/0077—Shaping by methods analogous to moulding, e.g. deep drawing techniques
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B2110/00—Shape of rigid or semi-rigid containers
  • B31B2110/10—Shape of rigid or semi-rigid containers having a cross section of varying size or shape, e.g. conical or pyramidal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Rigid or semi-rigid containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material or by deep-drawing operations performed on sheet material
  • B65D1/22—Boxes or like containers with side walls of substantial depth for enclosing contents
  • B65D1/26—Thin-walled containers, e.g. formed by deep-drawing operations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Rigid or semi-rigid containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material or by deep-drawing operations performed on sheet material
  • B65D1/34—Trays or like shallow containers

Definitions

• the present invention relates in general to the field of method and apparatus for dry manufacturing of rigid cellulose products having essentially non-flat general shape from a cellulose blank.
• Such cellulose products may be used for packaging, storing, transporting and/or displaying other products such as electronics, tools, jewelry, food, dairy products, cosmetics, etc., and/or may be used as single/multiple use disposable articles.
• the method and product forming unit are especially defined to secure reliable removal of the rigid cellulose product from the moulding tool after the pressing of the cellulose blank.
• the term cellulose products means products that mainly consists of the cellulose part of organic matter.
• the present invention relates specifically to a product forming unit and a method for dry manufacturing rigid cellulose products, the product forming unit comprising a moulding tool having a first mould part and a second mould part, wherein at least one of the first mould part and the second mould part is displaceable in the axial direction in relation to the other in order to press the cellulose blank therebetween into final shape by applying a predetermined pressure P in the axial direction of the moulding tool, and wherein the second mould part of the moulding tool comprises a main body and an ejector assembly having at least one ejector member.
• a biomaterial commonly used for packaging and disposable articles is wet moulded pulp based on cellulose fibres.
• Such wet moulded pulp has the advantage of being considered as a sustainable material, since it is produced from biomaterials and can be recycled after use.
• Wet moulded pulp comprises more or less only water and separated cellulose fibers, and consequently, wet moulded pulp has been popular to use for primary packaging applications (packaging next to the article), for secondary packaging applications (assembly of such primary packages), as well as for manufacturing of disposable articles/products.
• the moulding tool is usually made of a wire netting/cloth that is filled with a wet cellulose slurry and thereafter the cellulose slurry is dried and obtains the shape of the moulding tool.
• the final rigid cellulose product is easily removed from the wire netting.
• dry-forming techniques wherein rigid cellulose products are manufactured from separated cellulose fibres that are introduced into a product forming unit in the shape of a dry cellulose blank/web, wherein the cellulose blank is formed/moulded into the shape of the intended cellulose product and wherein the cellulose fibres are bonded to each other using heat and pressure.
• the dry-forming techniques comprises different steps of generating an air-laid cellulose blank, that is fed into a product forming unit, i.e. thermo-forming press.
• the cellulose blank that is fed/transported into the moulding tool is more or less fluffy, i.e. having a bulk of short/small separated cellulose fibres that are loosely connected to each other in the shape of a blank/web.
• the separated cellulose fibres will fill up and be pressed into all tiny recesses in the surfaces of the mould parts.
• there is an immediate risk especially for trays having a large bottom portion, that there will arise a vacuum condition between the pressed cellulose product and the bottom of the mould part when the suction device is lowered into contact with the cellulose product, and this may lead to fully unsatisfied removal or partial tearing of the cellulose product.
• the production/manufacturing has to be abruptly stopped and the machine be manually cleaned and checked. If the moulding tool is not empty upon start of the next loading/pressing cycle the moulding tool may become damaged.
• the suction device during lowering will contact the surface of the warm moulding tool and partly melt and stick to the surface of the first mould part, which will have negative effect on and discolour the next cellulose product to be pressed.
• the suction device will attach firmly to the metal surface and risk breaking the out-feed device when the suction device is raised to lift the non-present cellulose product.
• the system assumes that it has engaged/grasped the cellulose product and initiate lifting.
• WO2024/002723 figs 2c-2d
• the movable member is an ejector member configured to fully remove the pressed cellulose product away from the moulding tool when the ejector member is displaced from a retracted position to an extended position.
• WO2024/002723 further teaches that the movable element is always biased towards the extended position in order to insert the cellulose blank into the female mould part during closing of the forming mould and in order to eject the pressed cellulose product out from the forming mould.
• the present invention aims at obviating the aforementioned and other disadvantages and failings of previously known methods and devices for dry manufacturing rigid cellulose products, and at providing an improved product forming unit and method for dry manufacturing rigid cellulose products having non-flat general shape, wherein reliable removal of pressed cellulose product originating from an air-laid cellulose blank from the moulding tool is secured.
• a primary object of the present invention is to provide an improved product forming unit and method for dry forming/manufacturing rigid cellulose products having non-flat general shape, wherein the environmental benefits as well as time and energy saving benefits of conventional dry-forming techniques are maintained. It is another object of the present invention to provide an improved product forming unit and method for dry forming/manufacturing rigid cellulose products having non-flat general shape, wherein the pressed cellulose products are protected from damage during the step of removal of the cellulose product from the moulding tool. It is another object of the present invention to provide an improved product forming unit and method for dry forming/manufacturing rigid cellulose products having non-flat general shape, wherein the out-feed device is protected from damage during the step of removal of the cellulose product from the moulding tool.
• a product forming unit of the initially defined type wherein the at least one ejector member is displaceable between a retracted position and an extended position in relation to the main body of the second mould part, wherein said ejector member is biased towards said retracted position and configured to be pneumatically driven from the retracted position to the extended position in order to engage the cellulose product and remove the pressed cellulose product from the second mould part after the pressing of the cellulose blank.
• a method for dry manufacturing rigid cellulose products having essentially non-flat general shape from a cellulose blank using a product forming unit as defined herein above wherein the method comprises the steps:
• the present invention is based on the insight that in the default position the ejector member is biased towards the retracted position and thereby does not interfere with the insertion of the cellulose blank into the moulding tool or with the pressing of the cellulose blank in the moulding tool, and after the pressing of the cellulose blank the ejector member may be pneumatically activated in order to secure accurate conditions for subsequent removal of the pressed cellulose product from the moulding tool without damaging the pressed cellulose product or the out-feed device during the step of removal of the delicate cellulose product from the moulding tool.
• the present invention also provides the advantage that the ratio of successful removal of undamaged cellulose products will increase.
• the ejector assembly of the second mould part comprises a gas conduit extending from a high-pressure source to the product-volume defined between the first mould part and the second mould part, wherein the gas conduit is closed by means of the ejector member when the ejector member is in the retracted position, and wherein the gas conduit is open for gas flow from the high-pressure source to said product-volume when the ejector member is in the extended position in order to remove the pressed cellulose product from the second mould part after the pressing of the cellulose blank.
• the gas flow displacing the ejector member is also used to open the gas conduit and to engage/remove the pressed cellulose product from the second mould part.
• the force needed from the ejector member against the pressed cellulose product may be radically decreased and thereby the risk for generating marks on the surface of the cellulose product and/or perforation of the cellulose product is decreased.
• the travel distance of the ejector member between the retracted position and the extended position may be decreased.
• the second mould part comprises a scrap press-surface
• the ejector member constitutes at least a part of the scrap press-surface of the second mould part during pressing of the cellulose product.
• the ejector member preferably engages the scrap area in order to fully eliminate the risk of generating marks on the surface of the cellulose product.
• the first mould part of the moulding tool comprises a main body and an ejector assembly having at least one ejector member configured for removing the pressed cellulose product from the first mould part after the pressing of the cellulose product, the at least one ejector member being displaceable between a retracted position and an extended position in relation to the main body of the first mould part, wherein said ejector member is biased towards said retracted position and configured to be pneumatically driven from the retracted position to the extended position in order to engage the cellulose product and remove the pressed cellulose product from the first mould part after the pressing of the cellulose blank.
• the pressed cellulose product is firstly removed from the second mould part and thereafter the pressed cellulose product is removed from the first mould part, which secures and facilitates subsequent removal of the pressed cellulose product from the moulding tool.
• air/dry moulding/forming or air/dry laying/laid means a well-known method according to which separated cellulose fibres are formed into a cellulose blank/sheet.
• small/short fibres having a normal length in the range of 0,5 to 70 mm, for instance 1 to 10 mm are separated and captured by an air stream/flow, and then laid on/applied to a forming mesh/surface, usually using a low pressure at the other side of the mesh/surface.
• air/dry laying and “air/dry moulding” are used interchangeably herein.
• the cellulose fibre carrying air flow may be generated by suitable device located upstream and/or downstream the forming mesh/surface.
• figure 1 disclose a schematic illustration of a generic production line/apparatus for dry manufacturing rigid cellulose products, wherein said apparatus is generally designated 1.
• the production line 1 is configured for manufacturing rigid cellulose products, generally designated 2, having essentially non-flat general shape from separated cellulose fibres.
• Such a production line 1 may be arranged and set-up according to different well-known ways.
• Figure 13 disclose an example of a rigid cellulose product/tray 2.
• the apparatus 1 may have automatic transfer/handling between the different process steps, and/or may have manual transfer/handling between the different process steps, and thereto the apparatus 1 may have intermediate storing and/or additional process steps between the disclosed process steps, and/or the process steps may be located at different sites.
• Figure 13 disclose an example of a rigid cellulose product 2 in the shape of a tray/container, wherein the tray is formed using the inventive method.
• the tray 2 comprises an inclined circumferential wall 3 and an opening 4 defined by a circumferential rim/brim 5 connected to the upper/distal end of the wall 3.
• the brim 5 has an angled shape having an essentially radially extending upper surface and a turned-down outer edge, however it shall be pointed out that the cross-section of the brim 5 may have other shapes.
• the tray 2 may have truncated cone shape having straight wall 3, narrowing in the direction away from the opening 4, in accordance with figure 13 embodiment.
• the tray 2 may for instance have curved-shaped wall 3 seen in the axial plane.
• the tray could also be a mug/cup, a lid, packaging or the like container/product.
• the cross section of the circumferential wall 3 in the radial plane may have any suitable shape, circular, oval, rectangular, polygonal, etc., and may differ in shape and/or dimension along the axial extension of the tray 2.
• the tray 2 comprises a bottom 6, wherein the bottom 6 is entirely flat or the bottom may comprise local ribs, projections, etc., for strength and rigidity of the cellulose product.
• the bottom 6 may be located at the very lower end of the wall 3, according to figure 13 embodiment, and/or be partly located at an axial distance from the lower end of the wall 3, or a combination thereof.
• the circumferential wall 3 is connected to and extends in the axial direction upwards from the bottom 6. During use, the product 2 may be oriented in such a way that the bottom 6 is turned upwards.
• the separated cellulose fibres are thereafter transported by an air stream/flow to a dispenser of a cellulose blank/sheet forming unit 9.
• the cellulose fibres are laid by the dispenser on a moving or stationary perforated surface of the cellulose blank forming unit 9.
• the cellulose fibre carrying air flow may be generated by suitable device located upstream and/or downstream the perforated surface.
• the generated cellulose blank generally designated 10 is transported/transferred to a product forming unit 11, whereby rigid cellulose products 2 are formed and discharged from the product forming unit 11.
• the cellulose blank forming unit 9 may be configured to generate a continuous cellulose blank/web 10 and/or discontinuous/discrete cellulose blanks 10. Discontinuous/discrete cellulose blanks 10 are fed into the product forming unit 11.
• the cellulose raw material 7 may be in the form of reeled pulp or paper, bale of cellulose pulp, paper, etc. and/or sheets of paper, cellulose pulp, etc. In case said cellulose raw material 7 is in the form of sheets and/or reeled pulp or paper, it can be fed directly into the separating unit 8. However, in case said cellulose raw material 7 is in the form of a bale or compact stacks of sheets, etc. one or more shredders and/or one or more additional separating/disintegrating units 8 may be necessary to be used for separating and dosing said cellulose raw material 7 from said bale or sheets in smaller quantities. The shredder(s) prepare cellulose raw material 7 to be accepted by said separating unit 8.
• the separating unit 8 disintegrates the cellulose raw material 7 into separated cellulose fibres.
• Said one or plurality of shredder(s) are arranged before said one or a plurality of separating unit(s) 8, so that an output of one of said shredder is connected to an input of one of said separating units 8.
• the shredders may be arranged in parallel to each other or in series with each other, and the disintegrating units 8 may be arranged in parallel to each other or in series with each other.
• the shredders and the disintegrating units 8 together constitute a cellulose fibre separating unit, arranged upstream the cellulose blank forming unit 9.
• Said cellulose raw material 7 may be constituted by virgin cellulose fibres and/or recycled cellulose fibres and may originate from wood pulps such as kraft pulp, sulphite pulp, mechanical pulp, thermomechanical pulp (TMP), chemical treated mechanical pulp, chemi-thermomechanical pulp (CTMP), and/or from non-wood pulps such as bagasse, bamboo, abaca, hemp, flax, cotton.
• wood pulps such as kraft pulp, sulphite pulp, mechanical pulp, thermomechanical pulp (TMP), chemical treated mechanical pulp, chemi-thermomechanical pulp (CTMP), and/or from non-wood pulps such as bagasse, bamboo, abaca, hemp, flax, cotton.
• the separating unit 8 may according to various embodiments be constituted by a hammer mill.
• said separating unit 8 the cellulose raw material is separated into fibres having a normal length in the range of 0,5-70 mm, preferably less than 10 mm.
• the length of said fibres may be customized by adjusting the internal properties of the separating unit 8 and/or by choosing a different separating unit 8 and/or choosing different cellulose raw material 7.
• the fibre length for wood pulp is according to various embodiments in the range 0,5-4 mm, preferably in the range 1,7-3,6 mm.
• the fibre length for non-wood pulp is in the range 0,5-70 mm.
• the production line 1 may comprise a pre-compression and/or imprinting unit 12, located downstream the cellulose blank forming unit 9 and upstream the product forming unit 11.
• a pre-compression and/or imprinting unit 12 located downstream the cellulose blank forming unit 9 and upstream the product forming unit 11.
• an air-laid fluffy cellulose blank 10 having a first thickness may be compressed into a cellulose blank 10 having a second thickness, wherein said second thickness is thinner than said first thickness, and/or may be provided with an imprinting pattern.
• the cellulose blank is made more coherent and easier to handle, since the pre-compression/imprinting generates internal bindings between individual cellulose fibres preventing mutual separation of the cellulose fibres.
• the product forming unit 11 comprises a press unit 13, and may optionally comprise a pre-heating unit 14 arranged upstream the press unit 13.
• said cellulose blank 10 may be heated to an elevated temperature before being fed into the press unit 13 of the product forming unit 11.
• said press unit 13 may or may not comprise heating.
• said press unit 13 may be a heated press unit 13 for heating said cellulose blank 10 during pressing.
• preheating of said cellulose blank 10 using a pre-heating unit 14 is optional.
• preheating of the cellulose blank 10 in said pre-heating unit 14 may be combined with a heated press unit 13.
• Having a pre-heating unit 14 in combination with a heated press unit 13 will speed up the manufacturing process in the product forming unit 11, and improve the quality/rigidity of the final rigid cellulose product 2.
• the cellulose blank 10 is heated to a temperature in the range 120 - 200 °C in order to obtain adequate rigidity and strength in the final cellulose product 2.
• the press unit 13 comprises a moulding tool having a first mould part 15 and a second mould part 16 having co-operating designs, wherein at least one of the first mould part 15 and the second mould part 16 is/are displaceable in the axial direction in relation to each other, i.e. reciprocating back and forth in relation to each other, in order to exert pressure to the cellulose blank 10 loaded therebetween.
• the mutual displacement is disclosed as being vertical, however the mutual displacement may be horizontal or any other suitable angle.
• the cellulose blank 10 loaded into the moulding tool is constituted by the air-laid cellulose blank 10.
• the air-laid cellulose blank 10 may be generated upstream the product forming unit 11 in the same apparatus/production line and provided/transferred to the product forming unit 11, or may be generated at a separate location and provided/transferred to the product forming unit 11 via intermediate handling and storage.
• the first mould part 15 of the moulding tool is a female mould part, i.e. having a main recess 17 for receiving a major part of the cellulose blank 10
• the second mould part 16 of the moulding tool is a male mould part, i.e. having a main protrusion 18 for cooperation with said recess 17 of the female mould part by being inserted therein, such that the cellulose blank 10 is pressed into a final rigid non-flat shape by applying a predetermined pressure P in the axial direction of the moulding tool.
• the male/second mould part 16 is located above the female/first mould part 15, i.e.
• the pressed cellulose product 2 is intended to be collected from the female/first mould part 15 after the pressing of the cellulose blank 10.
• the female/first mould part 15 may be located above the male/second mould part 16, i.e. the pressed cellulose product 2 is intended to be collected from the male/second mould part 15 after the pressing of the cellulose blank 10.
• the latter alternative of the first embodiment is disclosed in figures 6-7 .
• the pressed cellulose product 2 is intended to remain in/on the first mould part 15 after the pressing of the cellulose product 2, irrespective of the angular orientation of the moulding tool.
• the pressed cellulose product 2 is intended to remain on the second mould part 16 after the pressing of the cellulose product 2, irrespective of the angular orientation of the moulding tool.
• the moulding tool has horizontal pressing direction, the pressed cellulose product 2 may be automatically removed/ejected from the moulding tool when the moulding tool is opened after the pressing of the cellulose blank 10.
• the male/second mould part 16 comprises a product press-surface and a scrap press-surface 19 adjacent said product press-surface.
• the product press-surface of the second mould part 16 comprises a bottom surface 20, a wall surface 21 connected to the bottom surface 20 and extending essentially in the axial direction, and a brim surface 22 connected to the wall surface 21 and extending essentially in the transversal/radial direction.
• the scrap press-surface 19 of the second mould part 16 surrounds the entire product press-surface.
• the scrap press-surface 19 of the second mould part 16 is only located at some locations around the product press-surface.
• the female/first mould part 15 comprises a product press-surface and a scrap press-surface 23 adjacent said product press-surface.
• the product press-surface of the first mould part 15 comprises a bottom surface 24, a wall surface 25 connected to the bottom surface 24 and extending essentially in the axial direction, and a brim surface 26 connected to the wall surface 25 and extending essentially in the transversal/radial direction.
• the scrap press-surface 23 of the first mould part 15 surrounds the entire product press-surface.
• the scrap press-surface 23 of the first mould part 15 is only located at some locations around the product press-surface.
• the scrap press-surface 23 of the first mould part 15 is arranged opposite the scrap press-surface 19 of the second mould part 16.
• some moulding tools does not comprise scrap press-surfaces, but the cellulose product 2 is formed in its final design without need for cutting/trimming.
• the cellulose blank 10 is pressed between the surfaces of the male/second mould part 16 and the surfaces of the female/first mould part 15 into final shape.
• the mutual distance, taken perpendicular to the surface in question, between the product press-surface of the female/first mould part 15 and the product press-surface of the male/second mould part 16 during the pressing of the cellulose blank 10 is T millimetres, wherein T preferably is in the range 0,2-2,5 millimetres, i.e. equal to the thickness of the bottom 6 of the pressed cellulose product 2.
• T is in the range 0,3-1,5 millimetres.
• the wall surfaces 21, 25 of the moulding tool has to be inclined in order to obtain a release angle for the cellulose product, and in order to obtain adequate press force to the wall region 3 of the cellulose product 2.
• the mutual distance between the scrap press-surface 23 of the first mould part 15 and the scrap press-surface 19 of the second mould part 16 is equal to or more than the mutual distance between the product press-surface of the first mould part 15 and the product press-surface of the second mould part 16.
• the part of the cellulose blank 10 located at the scrap area may be left entirely uncompressed in the moulding tool, be partially compressed by applying a predetermined partial pressure less than said predetermined pressure P, or be fully compressed by applying said predetermined pressure P.
• the cellulose blank 10 comprises a scrap area intended to be cut off.
• the cellulose product 2 is released and schematically removed from the moulding tool by opening the moulding tool.
• Figure 11 disclose a schematic illustration of a cellulose tray 2 wherein the scrap 27 is cut off from the cellulose tray 2.
• the scrap 27 may be removed in a separate step in the moulding tool, in a subsequent step outside the moulding tool after the pressing of the cellulose blank 10, or in a step concurrent with the pressing of the cellulose blank 10.
• a film/cover/lid may be attached to the circumferential rim/brim 5 of the cellulose tray 2, for instance using heat lamination.
• the lid film may be constituted by a multilayer film comprising polymer, metal, and/or paper.
• the rigid cellulose tray 2 Before any items are placed in the compartment of the rigid cellulose tray, the rigid cellulose tray 2 may be provided with a liner film adhered to at least to the circumferential rim/brim 5, and preferably also to the wall 3 and/or the bottom 6 of the cellulose tray 2.
• the liner film may be constituted by a multilayer film comprising polymer and/or metal. The adhesion of the liner film to the tray is preferably heat activated.
• the cellulose blank 10 may comprise barrier additives and/or material property enhancing additives, etc., such that the rigid cellulose tray 2 withstand grease, fat, water, vapour, etc.
• the additives are preferably provided to the cellulose fibers upstream the disintegrating unit 8 or between the disintegrating unit 8 and the product forming unit 11.
• the predetermined pressure P is in the range 40-10000N/cm 2 , preferably in the range 100-4000N/cm 2 . According to various embodiments said predetermined pressures are above 1000 N/ cm 2 , and according to various embodiments said predetermined pressures are below 2500 N/ cm 2 .
• the holding time during the pressing step is in equal to or more than 1 second and equal to or less than 10 seconds, preferably less than 5 seconds, and most preferably less than 3 seconds.
• the second mould part 16 of the moulding tool comprises a main body and an ejector assembly having at least one ejector member 28, wherein the main body according to the first embodiment comprises at least the main protrusion 18.
• the at least one ejector member 28 is displaceable between a retracted position and an extended position in relation to the main body of the second mould part 16.
• the ejector member 28 is biased towards said retracted position and configured to be pneumatically driven from the retracted position to the extended position in order to engage the cellulose product 2 and remove/release the pressed cellulose product 2 from the second mould part 16 after the pressing of the cellulose blank 10.
• the ejector assembly of the second mould part 16 may comprise a plurality of ejector members 28.
• the ejector member 28 is located in the retracted position during the pressing of the cellulose blank 10, according to figure 3 .
• the moulding tool is opened by displacing the second mould part 16 and the first mould part 15 away from each other, by displacing at least one of the second mould part 16 and the first mould part 15.
• the ejector member 28 is activated/displaced from the retracted position to the extended position whereby ejector member 28 engages the pressed cellulose product 2 and removes/ releases the cellulose product 2 from the second mould part 16, according to figures 4 and 7 .
• the pressed cellulose product 2 is in contact with the first mould part 15, i.e. adequate location for subsequent removal of the cellulose product 2 from the moulding tool.
• the ejector member 28 is deactivated/returned to the retracted position, according to figure 5 .
• the pressed cellulose product 2 is removed/released from the second mould part 16 but still located on the second mould part 16, i.e. adequate location for subsequent removal of the cellulose product 2 from the moulding tool.
• the ejector member 28 may be deactivated/returned to the retracted position.
• the ejector assembly of the second mould part 16 comprises a gas conduit 29 extending from a high-pressure source 30 to the ejector member 28.
• the gas flow in the gas conduit 29 is controlled, for instance by means of a controllable valve 31 located upstream the ejector member 28 or by turning the high-pressure source 30 ON and OFF.
• the high-pressure source 30 may comprise a pressure tank and/or a compressor.
• the ejector member 28 of the second mould part 16 is preferably biased towards the retracted position by means of a spring element 32, such as a coil spring.
• the ejector member 28 is biased towards the retracted position by means of a gas spring.
• the gas conduit 29 may also be connected to a low-pressure sink, wherein the ejector member 28 is biased towards the retracted position by means of the low-pressure sink.
• figures 8-10 disclosing a second schematic embodiment of the inventive product forming unit 11. Only differences in view of the first schematic embodiment will be specifically described. Thus, figures 8-10 correspond to figures 2-4 .
• the gas conduit 29 of the ejector assembly of the second mould part extends to the ejector body 28, passed the ejector body 28 and to the product-volume defined between the first mould part 15 and the second mould part 16.
• the gas conduit 29 is closed by means of the ejector member 28 when the ejector member 28 is located in the retracted position, and the gas conduit 29 is open for gas flow from the high-pressure source 30 to the product-volume when the ejector member 28 is located in the extended position.
• the ejector member 28 is driven from the retracted position to the extended position by means of the gas flow, and when the ejector member 28 is located in the extended position the gas flow is allowed to bypass the ejector member 28 and enter the product-volume.
• the ejector member 28 is configured and acts as a non-return valve.
• the gas flow assists in removing/releasing the pressed cellulose product 2 from the second mould part 16 after the pressing of the cellulose blank 10. Thereby the traveling/displacement distance of the ejector member 28 may be decreased and the contact force between the ejector member 28 and the pressed cellulose product 2 may be decreased.
• the ejector member 28 constitutes at least a part of the product press-surface of the second mould part 16 during pressing of the cellulose blank 10. As disclosed in for instance the schematic figures 2-10 . According to alternative embodiments, non-disclosed, the ejector member 28 constitutes at least a part of the scrap press-surface 19 of the second mould part 16 during pressing of the cellulose product 10. By pushing against the scrap area of the cellulose product 2, there is no risk in damaging the final cellulose product 2.
• These two alternative embodiments may also be combined, i.e. one ejector member 28 arranged in the product press-surface and one ejector member 28 arranged in the scrap press-surface, and/or one ejector member 28 arranged in both the product press-surface and the scrap press-surface.
• FIG 11 disclosing a third schematic embodiment of the inventive product forming unit 11.
• the first mould part 15 is now constituted by the male mould part and the second mould part 16 is now constituted by the female mould part.
• the other features of the first and second embodiments are unchanged and applicable to the third embodiment, mutatis mutandis.
• the figure 11 illustration comprises the ejector member 28 according the second embodiment disclosed in figures 8-10 , however it shall be realized that the ejector member 28 according to the first embodiment schematically disclosed in figures 2-7 is equally applicable.
• the herein used terms "second mould part” and "first mould part”, respectively, is a general teaching describing a moulding tool having two cooperating mould parts.
• the first alternative of the first embodiment, the second embodiment and the third embodiment, as disclosed in figures 2-5 and 8-11 , i.e. the second mould part 16 being located above the first mould part 15, are especially favourable when the inclination angle of the wall surfaces 21, 25 is small in relation to an axially extending plane and when the depth of the cellulose product 2 is extensive per se and/or in relation to the size of the bottom 6 of the cellulose product 6, i.e. the cellulose product 2 has a design that increases the risk of having the pressed cellulose product 2 sticking to the upper mould part, and the pressed cellulose product 2 is intended to be removed from the moulding tool from the first mould part 15.
• the second alternative of the first embodiment, as disclosed in figures 6-7 , i.e. the second mould part 16 is located below the first mould part 15, is especially favourable when the inclination angle of the wall surfaces 21, 25 is greater in relation to an axially extending plane and the size of the bottom 6 of the cellulose product 2 is extensive per se and/or in relation to the depth of the cellulose product 2, i.e. the cellulose product 2 has a design that increases the risk of having the pressed cellulose product 2 sticking to the lower mould part, and the pressed cellulose product 2 is intended to be removed from the moulding tool from the second mould part 15.
• FIG 12 disclosing a fourth schematic embodiment of the inventive product forming unit 11.
• the first mould part 15 is now constituted by the female mould part and the second mould part 16 is now constituted by the male mould part.
• the second mould part 16 comprises the ejector member 28 according the second and third embodiments disclosed in figures 8-11 , however it shall be realized that the ejector member 28 according to the first embodiment schematically disclosed in figures 2-7 is equally applicable.
• the first mould part 15 comprises a main body 33 and an ejector assembly having at least one ejector member 34, wherein the main body defines the recess 17.
• the at least one ejector member 34 of the first mould part 15 is displaceable between a retracted position and an extended position in relation to the main body of the first mould part 15.
• the ejector member 34 is biased towards said retracted position and configured to be pneumatically driven from the retracted position to the extended position in order to engage the cellulose product 2 and remove the pressed cellulose product 2 from the first mould part 15 after the pressing of the cellulose blank 10.
• the ejector body 34 of the first mould part 15 is configured in line with the ejector body 28 of the second mould part 16.
• the ejector assembly of the first mould part 15 may comprise a plurality of ejector members 34.
• the ejector member 34 is located in the retracted position during the pressing of the cellulose blank 10.
• the ejector member 34 of the first mould part 15 may be activated before, at the same time or after the activation of the ejector member 28 of the second mould part 16.
• the pressed cellulose product 2 is removed from the second/male mould part 15 and thereto it is secured that the pressed cellulose product 2 is released from the first/female mould part 15, in order to have an adequate location of the pressed cellulose product 2 for subsequent removal of the cellulose product 2 from the moulding tool, and the pressed cellulose product 2 is not fixed to any of the mould parts.
• the ejector assembly of the first mould part 15 comprises a gas conduit 35 extending from a high-pressure source 36 to the ejector member 34.
• the gas flow in the gas conduit 35 is controlled, for instance by means of a controllable valve 37 located upstream the ejector member 34 or by turning the high-pressure source 36 ON and OFF.
• the high-pressure source 36 may comprise a pressure tank and/or a compressor, and may be constituted by the same high-pressure source feeding the ejector member 28 of the second mould part 16.
• the ejector member 34 of the first mould part 15 is preferably biased towards the retracted position by means of a spring element 38, such as a coil spring. According to alternative embodiments, the ejector member 34 is biased towards the retracted position by means of a gas spring.
• the gas conduit 35 may also be connected to a low-pressure sink, wherein the ejector member 34 is biased towards the retracted position by means of the low-pressure sink.
• the gas conduit 35 of the ejector assembly of the first mould part extends to the ejector body 34, passed the ejector body 34 and to the product-volume defined between the first mould part 15 and the second mould part 16.
• the gas conduit 35 is closed by means of the ejector member 34 when the ejector member 34 is located in the retracted position, and the gas conduit 35 is open for gas flow from the high-pressure source 36 to the product-volume when the ejector member 34 is located in the extended position.
• the ejector member 34 of the first mould part 15 is driven from the retracted position to the extended position by means of the gas flow, and when the ejector member 34 is located in the extended position the gas flow is allowed to bypass the ejector member 34 and enter the product-volume.
• the ejector member 34 is configured and acts as a non-return valve. The gas flow assists in removing/releasing the pressed cellulose product 2 from the first mould part 15 after the pressing of the cellulose blank 10. Thereby the traveling/displacement distance of the ejector member 34 may be decreased and the contact force between the ejector member 34 and the pressed cellulose product 2 may be decreased.
• the out-feed device 39 comprises a movable arm 40 and a suction device 41 connected to said arm 40.
• the suction device 41 of the out-feed device 39 is insertable into the moulding tool between the first mould part 15 and the second mould part 16 after the pressing of the cellulose product 2 in order to engage the cellulose product 2 located in the first mould part 15 in the disclosed embodiment.
• the disclosed embodiment is the second alternative of the first embodiment, but the out-feed device 39 is applicable to all embodiments.
• the out-feed device 39 is configured to remove the pressed cellulose product 2 from the moulding tool in order to make the moulding tool empty and ready for the loading of the next cellulose blank 10.
• part of the out-feed device 39 is insertable into the moulding tool between the male/second mould part 16 and the female/first mould part 15 after the pressing of the cellulose product 2.
• the pressed cellulose product 2 is intended to be located in/on the first mould part 15 after the pressing of the cellulose product 2, and when the moulding tool is opened the cellulose product 2 is removed from the second mould part 16 by means of the ejector member 28.
• the out-feed device 39 may be arranged to transport the pressed cellulose product 2 to a subsequent step in the apparatus such as trimming of the scrap 27 and/or stacking.
• the out-feed device 39 makes use of a pneumatic arrangement to grasp and release the cellulose product 2.
• the movable arm 40 of the out-feed device 39 is mechanically controlled and operated, e.g. a robotic arm.
• the suction device 41 is insertable into the moulding tool between the male/second mould part 16 and the female/first mould part 15, and the suction device 41 is preferably inserted into the moulding tool during the opening of the moulding tool, i.e. when the second mould part 16 and/or the first mould part 15 are traveling away from each other after the pressing of the cellulose product 2.
• the pressing cycle time may be decreased, i.e. as long as the different members does not collide.
• the suction device 41 is a pneumatic arrangement, that preferably comprises a suction cup 42 configured to engage the cellulose product 2.
• the suction cup 42 may be made of a resilient material, a rigid material, or a combination thereof, wherein the pressure level in the volume defined by the suction cup 42 is controllable/adjustable.
• at least the lower rim of the suction cup 42 is made of a resilient material in order to obtain better air-tight seal between the suction device 41 and surface of the cellulose product 2.
• the pressure level in the volume defined by the suction cup may be above as well as below normal/ambient air pressure.
• a low pressure level entails that the suction device 41 engage/holds the cellulose product 2, and a high pressure level entails that the suction device 41 ejects/drops the cellulose product 2.
• normal/ambient air pressure is used in order to drop the cellulose product 2.
• the out-feed device 39 may comprise a high-pressure source HP and a low pressure source LP, wherein the suction device 41 is connected thereto and possibly also to ambient air using an assembly of conduits and controllable valves, in order to alternate therebetween.
• the out-feed device 39 may comprise only a low-pressure source LP, wherein the suction device 41 is connected thereto and to ambient air using an assembly of conduits and controllable valves, in order to alternate therebetween.
• the out-feed device 39 may comprise a plurality of suction devices 41.
• the low-pressure level is such that the total lifting force from the suction cup(s) 42 is preferably in the range 10-1000 times the weight of the cellulose product 2.
• FIG 15 disclosing the out-feed device 39 in the moulding tool according to the fourth embodiment.
• the pressed cellulose product 2 is lifted by the ejector member 34 such that the out-feed device 39 may engage/grasp the pressed cellulose product 2.
• the applied suction/lifting force by the suction device 41 can be lowered since it is guaranteed that the pressed cellulose product 2 is already released/removed from the first mould part 15.
• the method comprises the steps of:

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