Method and apparatus for dry production of rigid cellulose products

Abstract

The present invention relates to an apparatus (100) and a method for dry manufacturing of a rigid cellulosic product having an essentially non-flat overall shape. The apparatus (100) comprises a disintegrating unit (3), a cellulose blank forming unit (30) and a product forming unit (40) for making a rigid cellulosic product (14). The cellulose blank forming unit (30) comprises a dispenser for directing a cellulose fiber carrying air stream from the disintegrating unit (3), a forming drum (15) having an outer surface including perforations, the outer surface being configured to receive the cellulose fibers and form a cellulose blank (13), an air removal device (54) arranged within the forming drum (15) and a support structure (8) for receiving the cellulose blank (13) from said forming drum (15). The apparatus (100) is characterized in that the outer surface of a forming drum (15) includes a first area having a first perforation density and a second area having a second perforation density less than the first perforation density, forming a continuous or discontinuous cellulose blank (13) having a higher basis weight at a first location derived from the first area than at a second location derived from the second area.

Description

TECHNICAL FIELD

[0001] The present invention generally relates to a method and apparatus for dry manufacturing of rigid cellulose products having an essentially non-flat general shape. Cellulose products can be used for packaging, storing, transporting and / or displaying other products such as electronic devices, tools, jewelry, food, dairy products, cosmetics, and / or can be used as disposable articles for single or multiple uses. The present invention also relates to rigid cellulose products, and continuous or discontinuous cellulose blanks. BACKGROUND ART

[0002] In many situations, it is desirable to provide objects of two-dimensional (2D) or three-dimensional (3D) shape made from sustainable materials. A material commonly used for packaging inserts is wet-formed pulp. Wet-formed pulp has the advantage that it is made from biomaterials and can be recycled after use, so it is considered a sustainable packaging material. As a result, molded pulp is rapidly growing in popularity for both primary and secondary packaging applications (the packaging of subsequent articles and the assembly of such packaging).

[0003] A disadvantage common to all wet forming techniques is that a large amount of water is required during manufacturing and drying of the molded product is required, which is a time and energy consuming process, thereby reducing production rate and substantially increasing investment costs for machinery and tooling. This means that it is not feasible for this technology to replace fossil-based alternatives on a large scale.

[0004] Furthermore, many modern lean production lines require the manufacture of packaging or components based on in-line demand, where wet forming processes are undesirable or impractical. Recently, new fiber-based materials have been developed with the aim of enabling the dry forming of three-dimensional objects / products. One method is disclosed by WO2014 / 142714. WO2014 / 142714 discloses a dry-assembled composite web, an intermediate product for thermoforming objects of three-dimensional shape, comprising 40-95 wt% CTMP fibers, 5-50 wt% thermoplastic material, and 0-10 wt% additives, wherein the dry-assembled composite web is impregnated in a dispersion, emulsion, or solution containing the thermoplastic material and polymer, dried, and obtains a density of 50-250 kg / m3, or 400-1000 kg / m3 if compressed by calendering. According to WO2014 / 142714, polymer bonding is activated by the higher temperatures applied during the thermoforming process, contributing to the final strength of the thermoformed object.

[0005] When cellulose fiber sheets are formed using an air / dry agglomeration process, the network strength of the cellulose fibers is generally weakened, i.e., the self-supporting properties are reduced. The air-agglomerated sheets / blanks can become intermediate products in the dry cellulose formation / manufacturing process for products that are inherently non-flat. Due to the fragility of these intermediate products, it may be necessary to improve the self-supporting properties of the sheets to improve the efficiency and flexibility of the manufacturing process for the rigid cellulose products that have an inherently non-flat overall shape.

[0006] Cellulose fibers are highly hygroscopic, and air / dry agglomeration processes have been identified as being susceptible to process conditions such as electrostatic charge, airflow, and humidity. Because cellulose fibers tend to clump together, resulting in non-uniform / unpredictable basis weight / thickness of the blank, this behavior of cellulose fibers makes it difficult to provide a uniform blank / sheet of cellulose fibers on the forming structure / web. In the art, attempts have been made to provide solutions to control the properties / basis weight of cellulose blanks, namely using the tower forming unit described in SE1750313, with fiber separation brushes and a first compression roller to obtain a uniform cellulose blank in both axial and transverse directions. The non-uniform basis weight of the cellulose blank can be compensated to some extent by the hydrostatic pressing treatment described in EP3429928. However, this is a more complex process in terms of tools, requires longer process times, and is more complicated overall. The problem with this forming tower and hydrostatic pressing process is that it is rather complex, with all its mechanical components provided to distribute the cellulose fibers as uniformly as possible on the forming web. A common problem in pressing processes for forming 3D-shaped components / products is that the complex structure / design of the components and / or the depth of the product can cause cracks in the cellulose fiber sheet / blank.

[0007] A more reliable dry cellulose formation / manufacturing process for inherently non-flat rigid cellulose products is needed in this field, which reduces or eliminates the risk of cracking during the pressing process. [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to prevent the aforementioned and other drawbacks and weaknesses of previously known methods and apparatus for the dry production of rigid cellulose products, and to provide an improved method and apparatus for the dry production of rigid cellulose products having an essentially non-flat overall shape.

[0009] The primary object of the present invention is to provide an improved method and apparatus for dry forming / manufacturing rigid cellulose products having an essentially non-flat overall shape from cellulose fibers. Another object of the present invention is to provide a method and apparatus for manufacturing rigid cellulose products, which inevitably results in the absence of cracks in the manufactured cellulose products that would normally be caused by pressing the cellulose products. Another object of the present invention is to provide a method and apparatus for manufacturing rigid cellulose products, in which the basis weight of the cellulose blank may be adjusted to obtain a final cellulose product having the required characteristics / properties such as rigidity, thickness, and basis weight. Another object of the present invention is to provide a method and apparatus for manufacturing rigid cellulose products, which can produce continuous or discontinuous cellulose blanks. Another object of the present invention is to provide a method and apparatus for manufacturing rigid cellulose products that generate less fragmentation / waste. Another object of the present invention is to provide a method and apparatus for manufacturing rigid cellulose products, in which the blank forming unit is not very complex. [Means for solving the problem]

[0010] According to the present invention, at least the primary objective is achieved by the initially defined method and apparatus having the features defined in the independent claim. Preferred embodiments of the present invention are further defined in the dependent claims.

[0011] According to a first aspect of the present invention, - A decomposition unit for providing a certain amount of cellulose fibers separated from a cellulose raw material, - A cellulose blank forming unit, - Dispenser for guiding the cellulose fiber carrying air flow from the decomposition unit. - A forming drum having an outer surface including perforations, the outer surface configured to receive cellulose fibers from the amount of separated cellulose fibers transported by airflow through a dispenser, and to form a cellulose blank, - An air removal device placed inside the forming drum, and - A cellulose blank forming unit comprising a support structure for receiving the cellulose blank formed on the forming drum, - An apparatus comprising a product forming unit for producing a rigid cellulose product having an essentially non-flat overall shape from a cellulose blank by pressing, The apparatus is provided, characterized in that the outer surface of the forming drum includes a first area having a first perforation density and a second area having a second perforation density less than the first area, and a continuous or discontinuous cellulose blank is formed having a basis weight at a first position originating from the first area and a higher basis weight at a second position originating from the second area.

[0012] According to a second aspect of the present invention, - A step of providing a certain amount of separated cellulose fibers by breaking down a cellulose raw material, - A step of transporting separated cellulose fibers to the outer surface of a forming drum by airflow, wherein the outer surface of the forming drum includes perforations, - A step of forming a continuous or discontinuous cellulose blank on the outer surface of a forming drum by removing air from the inside of the forming drum in order to temporarily hold cellulose fibers on the outer surface of the forming drum, - A step of transferring a continuous or discontinuous cellulose blank from a forming drum to a support structure, - The process includes the step of producing a rigid cellulose product having an essentially non-flat overall shape by pressing a continuous or discontinuous cellulose blank in a product forming unit, A method is provided in which a continuous or discontinuous cellulose blank includes a first position and a second position, the first position having a higher basis weight than the second position, the first position originating from a first area on the outer surface of a forming drum having a first perforation density, and the second position originating from a second area on the outer surface of a forming drum having a second perforation density lower than the first perforation density.

[0013] Therefore, the present invention is based on the insight that the outer surface of the forming drum has a non-uniform perforation density, and thus different amounts of cellulose fibers adhere to different parts of the rotating forming drum, thereby the continuous or discontinuous cellulose blanks may have different / variable basis weight or surface weight in the axial and / or radial directions.

[0014] The advantage of the present invention is that this method and apparatus provides the cellulose blank with appropriate strength and rigidity and prevents cracking in the cellulose blank when producing / pressing the rigid cellulose product which has an essentially non-flat overall shape.

[0015] Another advantage of the present invention is that the basis weight of the cellulose blank can be easily adjusted to obtain the required properties of the essentially non-flat rigid cellulose product to be produced. According to various exemplary embodiments of the present invention, the cellulose blank is discontinuous in the axial and / or transverse directions, i.e., perpendicular and / or parallel to the direction of motion of the support structure / web. An advantage of these embodiments is that individual strips and / or tiles of the cellulose blank having sufficient basis weight in the axial and transverse directions may be formed for subsequent use in a press tool for producing essentially non-flat rigid cellulose products.

[0016] According to various embodiments of the present invention, the second perforation density of a second area on the outer surface of the forming drum is equal to 0, and as a result, the basis weight of the cellulose blank derived from these second areas is also 0, i.e., individual sheetlets of cellulose blank, i.e., strips and / or tiles, are provided.

[0017] According to various embodiments of the present invention, the outer surface of the forming drum comprises a main envelope surface and one or more recesses provided in the main envelope surface, a first section having a first perforation density is located in said one or more recesses, forming a continuous or discontinuous cellulose blank having a higher basis weight at a position originating from said first section than at a position originating from a second section.

[0018] The advantage of having recesses in the forming drum to generate higher basis weight portions of continuous or discontinuous cellulose blanks, i.e., locations having more cellulose fibers, is that it makes it easier to sort / encapsulate the production process of air / dry-depositing cellulose fibers onto the forming drum. Furthermore, it will be appreciated that the forming drum may be adapted in various ways to the final cellulose product to reinforce areas particularly susceptible to cracking and / or to stiffen certain areas of the product.

[0019] According to various embodiments of the present invention, the cellulose blank forming unit further comprises a second forming drum having an outer surface comprising perforations, the outer surface being configured to receive cellulose fibers from an amount of separated cellulose fibers transported by an air flow and form a cellulose blank, and a second air removal device arranged within the second forming drum.

[0020] The use of the second forming drum is based on the insight that it provides a continuous or discontinuous cellulose blank of additional cellulose fibers intended to be connected to the continuous or discontinuous cellulose blank of the (first) forming drum before the rigid cellulose product is produced / pressed. Thereby, the ability to adjust the basis weight at different locations of the continuous or discontinuous cellulose blank arriving at the product forming unit is further enhanced.

[0021] Cellulose fibers from the (first) forming drum and the second forming drum may be added to the support structure simultaneously with a single continuous or discontinuous cellulose blank or separately, so that a final continuous or discontinuous cellulose blank is formed on the support structure.

[0022] According to various embodiments of the present invention, the cellulose fibers of the (first) forming drum and the second forming drum are of different types, that is, different raw materials, different fiber sizes, different additives, etc.

[0023] An advantage of these embodiments is that the mechanical properties of the final cellulose product may be adjusted to meet specific requirements. Further advantages and features of the present invention will be apparent from the following detailed description of preferred embodiments.

[0024] A more complete understanding of the above and other features and advantages of the present invention will be obtained from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings. Brief Description of the Drawings

[0025] [Figure 1] Fig. 1 is a schematic diagram of one exemplary embodiment of an apparatus for dry manufacturing a rigid cellulose product having an essentially non-planar overall shape from a cellulose raw material, wherein the cellulose blank is continuous. [Figure 2] Figs. 2A and 2B are respectively a cross-sectional view and a schematic top view of one exemplary embodiment of a continuous cellulose blank having a basis weight variable in the axial direction and the transverse direction. [Figure 3] Fig. 3 is a schematic diagram of one exemplary embodiment of an apparatus for dry manufacturing a rigid cellulose product having an essentially non-planar overall shape from a cellulose raw material, wherein the cellulose blank is discontinuous. [Figure 4] Figs. 4A and 4B are respectively a cross-sectional view and a schematic top view of one exemplary embodiment of a discontinuous cellulose blank discontinuous in the axial direction and the transverse direction. [Figure 5] Fig. 5 is a schematic diagram of an outer surface of a forming drum having a recess in a main envelope surface. [Figure 6] This is a schematic diagram of one exemplary embodiment of an apparatus for dry-processing rigid cellulose products having an essentially non-flat overall shape from cellulose raw materials, in which product forming units are arranged in a continuous sequence. [Figure 7] This is a schematic diagram of one exemplary embodiment of an apparatus for dry-processing rigid cellulose products having an essentially non-flat overall shape from cellulose raw materials, in which a cellulose blank is produced by two forming units. [Figure 8] This is a schematic diagram of one exemplary embodiment of an apparatus for dry-processing rigid cellulose products having an essentially non-flat overall shape from cellulose raw materials, in which a cellulose blank is produced by two forming units. [Figure 9] This is a schematic diagram of one exemplary embodiment of an apparatus for dry-processing rigid cellulose products having an essentially non-flat overall shape from cellulose raw materials, wherein different cellulose raw materials are supplied to two separate forming units. [Figure 10] This is a schematic diagram of one exemplary embodiment of an apparatus for dry-processing rigid cellulose products having an essentially non-flat overall shape from cellulose raw materials, with alternative compression rolls. [Modes for carrying out the invention]

[0026] In this specification, the term “air / dry forming or air / dry stacking” means a well-known method by which separated cellulose fibers are formed into a cellulose blank / sheet.

[0027] In air agglomeration, small fibers having an average length in the range of 1 to 50 mm are separated and captured by an airflow and then agglomerated onto the forming mesh / forming surface, usually using vacuum / low pressure on the other side of the mesh / surface. The terms "air agglomeration" and "air forming" are used without distinction herein. The cellulose fiber transport airflow may be generated by suitable devices located upstream and / or downstream of the forming mesh / forming surface.

[0028] Figures 1, 3, 6, 7, 8, 9, and 10 disclose various exemplary embodiments of an apparatus for dry manufacturing rigid cellulose products to produce cellulose products 14 having an essentially non-flat overall shape from cellulose fibers, the entire apparatus referred to as 100. Embodiments from different figures may be combined.

[0029] The entire apparatus 100 of the present invention is described with reference to Figure 1, and the apparatus 100 comprises a separation / decomposition unit 3, a cellulose blank / sheet forming unit 30, and a final product forming unit 40. Cellulose raw material 1 is supplied to the decomposition unit 3. Cellulose raw material 1 may be in the form of wound pulp or paper 1a, bale 1b of cellulose pulp, paper, etc., and / or sheet 1c of paper, cellulose pulp, etc. If the cellulose raw material 1 is in the form of sheet 1c and / or wound pulp or paper 1a, it may be supplied directly into the separation unit 3. However, if the cellulose raw material 1 is in the form of a compressed stack of bale 1b or sheet 1c, etc., it may be necessary to use one or more shredders 18 and / or one or more additional separation / decomposition units 3 to separate and inject the cellulose raw material from the bale 1b or sheet 1c in smaller quantities. The shredder 18 prepares the cellulose raw material 1 for acceptance by the separation unit 3. The separation / decomposition unit 3 decomposes the cellulose raw material 1 into separated cellulose fibers. The one or more shredders 18 are located upstream of the one or more separation units 3, and the output of one of the shredders 18 is connected to the input of one of the separation units 3. The shredders 18 may be arranged parallel to each other or perpendicular to each other, and the decomposition units 3 may be arranged parallel to each other or perpendicular to each other. The shredders 18 and the decomposition units 3 together constitute a cellulose fiber separation unit located upstream of the cellulose blank forming unit 30.

[0030] The cellulose fibers may be unused cellulose fibers and / or recycled cellulose fibers, and may be derived from wood pulp such as kraft pulp, sulfite pulp, mechanical pulp, thermomechanical pulp (TMP), chemically treated mechanical pulp, chemothermetic pulp (CTMP), and / or non-wood pulp such as bagasse, bamboo, Manila hemp, hemp, flax, and cotton.

[0031] According to various embodiments, the separation unit 3 may be composed of a hammer mill. In the separation unit 3, the cellulose raw material is separated into fibers having an average length in the range of 1 to 50 mm. The length of the fibers may be customized by adjusting the internal properties of the separation unit 3 and / or by selecting different separation units 3 and / or by selecting different cellulose raw materials. According to various embodiments, the fiber length of wood pulp is in the range of 0.5 to 4 mm, preferably in the range of 1.7 to 3.6 mm. According to various embodiments, the fiber length of non-wood pulp is in the range of 0.5 to 70 mm.

[0032] Generally, in air / dry forming / air aeration methods, wood pulp fibers are individualized / separated using, for example, a hammer mill, and transported by airflow through a dispenser, which distributes the fibers substantially uniformly in the transverse direction of the fabrication apparatus. The fibers are accreted onto a moving perforation surface using an airflow generated beneath its surface by a vacuum / low-pressure chamber. As described above, the cellulose fiber transport airflow may be generated by suitable devices located upstream and / or downstream of the perforation surface.

[0033] In Figure 1, individualized / separated cellulose fibers are supplied to a cellulose blank / sheet forming unit 30. In the schematic embodiment shown in Figure 1, the cellulose blank forming unit 30 comprises a fan 4, a forming drum / cylinder 15, and a support structure / web 8. The fan 4 is positioned between the separation unit 3 and the forming cylinder 15, and the disintegration unit 3 is connected to the fan 4. The fan 4 generates a cellulose fiber transport airflow, blowing the cellulose fibers from the separation unit 3 onto the outer surface of the forming cylinder 15 via a dispenser extending between the disintegration unit 3 and the forming cylinder 15. According to various exemplary embodiments, the application of the fibers onto the forming cylinder 15 is performed at an angle to the outer surface of the forming cylinder 15. According to various exemplary embodiments, the angle is 90°, i.e., the fibers are applied perpendicular to the outer surface of the forming cylinder 15. According to various exemplary embodiments, the angle is less than or greater than 90°, i.e., the cellulose fibers are applied not perpendicular to the outer surface of the forming drum / cylinder 15. The predetermined angular interval 5 of the forming cylinder 15 is under vacuum / low pressure conditions. The forming drum 15 rotates continuously at a predetermined speed, and the angular interval 5 is stationary. Therefore, the outer surface of the forming drum 15 passes through the angular interval 5.

[0034] The separated cellulose fibers may flow at a fiber / air concentration of approximately 500g of cellulose fibers per cubic meter of air, and the moisture content of the air is 5-20g of water / kg of air in the separation unit 3 and / or the cellulose blank forming unit 30.

[0035] The outer surface of the forming cylinder 15 is perforated. To impart the cellulose fibers containing air onto the outer surface of the forming drum / cylinder 15, air inside the forming drum 15 is removed at angular intervals 5, and the cellulose fibers remain attached to the perforated outer surface, i.e., the cellulose fibers are attracted to the outer surface of the forming drum 15. The air is removed by an air removal device 54 located inside the forming drum 15, i.e., at least a portion of the air removal device 54 is located inside the forming drum 15. The air removal device 54 is configured to remove at least the same amount of air introduced by the fan 4 generating a cellulose fiber transport airflow. The separated cellulose fibers then adhere to / accumulate on the outer surface of the forming drum 15 at the locations with perforations. As the cellulose fibers accumulate on the outer surface of the forming drum 15, a cellulose blank 13 is formed. The amount of cellulose fibers in the airflow from the fan 4, the velocity of the airflow from the fan 4, the velocity of the outer surface of the forming drum 15, the perforation density of the outer surface, etc., determine the basis weight of the formed cellulose blank 13. Alternatively, the air removal device 54 also performs the task of the fan 4, thereby becoming a single device that generates the cellulose fiber transport airflow.

[0036] The cellulose blank 13 is removed from the forming drum / cylinder 15 and applied to or received by the support structure / web 8. For this reason, only the predetermined angular interval 5 of the forming cylinder 15 has the vacuum / low-pressure condition. The angular interval 5 overlaps with the airflow from the fan 4. The vacuum condition is released / terminated in front of the outer surface of the forming cylinder 15, or at the position of the outer surface of the forming cylinder 15 closest to the support structure 8, thereby allowing the cellulose blank / sheet 13 to be released from the forming cylinder 15 and applied to the support structure 8. The support structure 8 may be a continuous web or a continuous belt, as shown in Figure 1. The rotation / surface speed of the forming cylinder 15 is synchronized with the speed of the support structure 8. A fan 54 may be provided to create pressurization within the forming cylinder 15 at the angular interval 5.

[0037] The support structure 8 may also be a discontinuous web. The discontinuous web may be movable back and forth to capture the cellulose blank / sheet and deliver the cellulose blank / sheet to further process steps. The cellulose blank may be discontinuous, i.e., a stack of multiple sheetlets of cellulose blank, or continuous, i.e., a folded cellulose blank.

[0038] The cellulose blank 13 is then supplied into the product forming unit 40 from the same production line as the cellulose blank forming unit 30, or from intermediate storage between the cellulose blank forming unit 30 and the product forming unit 40. According to various embodiments, the product forming unit 40 comprises a press unit 12 having a molding tool 11. The molding tool 11 includes the design / construction of the final rigid cellulose product having a male portion and a corresponding female portion, and having an essentially non-flat overall shape. In Figure 1, an optional preheating unit 16 is located upstream of the press unit 12. According to various exemplary embodiments, the cellulose blank 13 may be heated to a high temperature before being supplied into the press unit 12 of the product forming unit 40. In such embodiments where the cellulose blank 13 is preheated before being supplied into the press unit 12 of the product forming unit 40, the molding tool 11 may or may not include heating. According to various exemplary embodiments, the molding tool 11 in the press unit 12 may be a heated molding tool 11 for forming the final cellulose product 14 while heating the cellulose blank 13. In the case of the heat molding tool 11, preheating of the cellulose blank 13 by the preheating unit 16 is optional. According to various exemplary embodiments, preheating of the cellulose blank 13 in the preheating unit 16 is combined with the heat molding tool 11. In such cases, the preheating unit 16 may heat the cellulose blank 13 to a first temperature, and the molding tool 11 heats the cellulose blank 13 to a second temperature while pressing / forming the final cellulose product 14. The first and second temperatures may be different or equal. According to various exemplary embodiments, preheating may be performed to reach an intermediate temperature, which is then increased to a final temperature by the molding tool 11. The intermediate temperature may be between the final temperature and room temperature. According to various exemplary embodiments, the intermediate temperature may be close to the final temperature. Having the preheating unit 16 in combination with the heat molding tool 11 accelerates the manufacturing process in the press unit 12.The preheating unit 16 may heat the cellulose blank 13 from one side, i.e., the top or bottom, or from both sides, i.e., the top and bottom. The molding tool 11 may heat one or both of the male and female parts, and / or the male and female parts may have different temperatures. The optional preheating unit 16 may be an IR heater or a resistance heater, with or without a fan.

[0039] Within the molding tool 11, the cellulose blank 13 is heated to a temperature of 120-200°C to obtain sufficient rigidity and strength in the final cellulose product 14. According to various exemplary embodiments, the cellulose blank 13 may be preheated to 100°C before reaching the press unit 12 of the product forming unit 40, where the cellulose blank is heated to 120-200°C by the molding tool 11. According to various exemplary embodiments, the cellulose blank is heated to 120-200°C by the preheating unit 16 so that no excess heat is delivered to the cellulose blank during the molding of the final cellulose product 14. According to various exemplary embodiments, heating of the cellulose blank 13 is performed only within the press unit 12 of the product forming unit 40 during the formation of the final cellulose product 14, i.e., no preheating is performed.

[0040] The apparatus 100 may comprise one or more humidifier units 17a to 17c. According to various exemplary embodiments, a first humidifier unit 17a may be positioned to humidify the ambient air and / or the internal volume of the apparatus 100, particularly in the decomposition unit 3 and / or cellulose blank forming unit 30, in order to ensure proper humidity for the cellulose fibers. According to various exemplary embodiments, a second humidifier 17b may be positioned before the separation / decomposition unit 3, i.e., at the inlet to the separation unit 3, to humidify the cellulose raw material entering the separation unit 3. According to various exemplary embodiments, a third humidifier 17c may be positioned at the outlet of the separation unit 3 to humidify the cellulose fibers discharged from the separation unit 3. The third humidifier 17c may be positioned at the inlet of a fan 4 provided for extracting fibrous material from the separation unit 3 and spraying the same fibrous material onto the forming cylinder 15. A third humidifier may also be positioned on the fan 4 to mix the incoming air with the fibrous material at the desired humidity before applying the cellulose fibers onto the cylinder 15. Humidifiers 17a, 17b, and 17c may provide water in liquid and / or gaseous form. Humidifiers 17b and 17c may, alternatively, be used to provide additives / chemicals other than water in liquid and / or gaseous form.

[0041] The cellulose blank requires a moisture content within a specified range. As mentioned above, the moisture content of the air is 5-20 g of water per 1 kg of air in the separation unit 3 and / or the cellulose blank forming unit 30. According to various exemplary embodiments, the moisture content of the air is 9-12 g of water per 1 kg of air in the separation unit 3 and / or the cellulose blank forming unit 30. If the moisture content of the cellulose fibers is too low, the risk of static electricity increases, resulting in uneven formation of the cellulose blank, which in turn affects the basis weight of the cellulose blank. If the moisture content is too high, the cellulose fibers become clogged, which in turn affects the basis weight of the cellulose blank.

[0042] According to various exemplary embodiments, one or more optional chemical injection units may be provided and configured to increase the network strength of the cellulose blank 13. In the first exemplary embodiment, at least one first chemical injection unit 9a-9c is provided to apply a liquid binder to the bottom or top surface of the cellulose blank to form a support layer.

[0043] The liquid binder may be allowed to penetrate from either side of the cellulose blank / sheet 13 to a penetration depth of less than 50% of the thickness within the cellulose blank 13. According to various exemplary embodiments, the penetration depth of the liquid binder is 5–49% of the overall thickness of the cellulose blank 13. According to various exemplary embodiments, the penetration depth of the liquid binder is 10–30% of the overall thickness of the cellulose blank 13. The injection unit 9a may apply the liquid binder before receiving the cellulose blank 13 onto the support web 8. In this case, the liquid binder is provided on the bottom side of the cellulose blank. The injection unit 9b may apply the liquid binder onto the cellulose blank 13. The injection unit 9c may apply the liquid binder before the press unit 12 of an optional preheating unit 16 and / or product forming unit 40. In Figure 1, the liquid binder is shown to be provided on the bottom side of the cellulose blank 13. However, the liquid binder may, as an additional / alternative measure, be provided on the top side of the cellulose blank 13, at the same location as the injection unit 9c below the cellulose blank. According to various exemplary embodiments, the shown injection units 9a-9c may be provided individually, i.e., only one of 9a, 9b, or 9c may be provided. According to various exemplary embodiments, the shown injection units 9a-9c may be provided in combination of two or more, i.e., 9a and 9b, 9b and 9c, 9c and 9a, or 9a, 9b, and 9c may be provided. The liquid binder may be an organic liquid or an inorganic liquid. The final cellulose product 14 is, accordingly, a laminated product, and different layers may have different properties and thicknesses. Increases in the strength and / or stiffness of the final cellulose product 14 may be achieved by adding liquid binders such as starch, plant gum, CMC, MFC, synthetic and natural polymers, organic acids, latex, modified cellulose, and / or lignin. The liquid binder does not include thermoplastic resins. The liquid binder may be an organic or inorganic liquid, and may be, for example, a natural polymer or wax extracted from a plant, potassium oxide or magnesium oxide (water glass), or a silica compound.The penetration depth may be altered by changing the pressure of the liquid binder in the injection units 9a-9c, and / or by changing the discharge pattern of the injection units 9a-9c, and / or by changing the speed of the cellulose blank 13, and / or by changing the size of the orifice that discharges the liquid binder, and / or by changing the number of orifices that discharge the liquid binder, and / or by changing the duty cycle of discharge of the liquid binder from at least one of the injection units. Additionally, the viscosity and / or pressurization of the additive / agent on the other side of the cellulose blank directly affects the penetration depth.

[0044] The final cellulose product 14 is formed in the press unit 12 of the product forming unit 40. The pressure that the press unit 12 applies to the molding tool 11 is 40 to 10,000 N / cm². 2 It may be so. According to various exemplary embodiments, the pressure is 100 to 4000 N / cm². 2 According to various exemplary embodiments, the pressure is 400 N / cm². 2 It exceeds this value, preferably 1000 to 3900 N / cm². 2 That is the case.

[0045] According to various exemplary embodiments, before the forming / molding step, a liquid or solid agent may be applied to the cellulose material to alter the hydrophobic and / or oleophobic characteristics / properties of the essentially non-planar cellulose product 14. In Figure 1, this is illustrated by a second chemical injection unit 2, which applies a liquid agent to the wound pulp or paper 1a before it enters the separation unit 3. The liquid or solid agent for altering the hydrophobic and / or oleophobic properties of the essentially non-planar cellulose product 14 may be a starch compound, a rosin compound, a butanetetracarboxylic acid, a gelatin compound, an alkylketene dimer (AKD), an alkenyl succinic anhydride (ASA), a wax compound, a silicon compound, and / or a calcium compound, and may be added at a dry content of 0.2–15%, preferably 0.5–12%. As described below, when using parallel decomposition units 3, different chemicals / agents may be applied to different cellulose raw materials 1 supplied into individual decomposition units 3.

[0046] According to various exemplary embodiments, when the cellulose blank is provided into the molding tool 11, the moisture content of the cellulose blank 13 is at least 5%. According to various exemplary embodiments, when the cellulose blank is provided into the molding tool 11, the moisture content of the cellulose blank 13 is 7-12%.

[0047] The formation of the cellulose blank 13, i.e., the control of the basis weight of the cellulose blank 13, is critical to the properties resulting in the final cellulose product 14. When the design / structure of the final cellulose product 14 is complex, conventional solutions do not provide sufficient rigidity / strength to the final cellulose product 14, and cracks occur during pressing in the forming unit 40. The present invention is based on the insight that the cellulose blank 13 must have different basis weights at different locations so that the final cellulose product 14 has the required properties in terms of rigidity / strength / basis weight and does not exhibit / contain cracks. By having different basis weights at different locations in the cellulose blank 13, the final cellulose product 14 can have a uniform basis weight and / or a high basis weight at specified locations.

[0048] To generate / form cellulose blanks having different basis weights at different locations on the outer surface of the forming drum 15, the outer surface of the forming drum 15 includes a first area having a first perforation density and a second area having a second perforation density lower than the first perforation density. Perforation density means the ratio of the area with openings to the area without openings. The dimensions of individual openings may be the same or different throughout the forming drum 15. Since the first perforation density is higher than the second perforation density, i.e., more air is drawn through the outer surface of the forming drum 15 in the first area than in the second area, and more cellulose fibers adhere to the outer surface of the forming drum 15 in the first area than in the second area. As a result, the forming drum 15 generates continuous or discontinuous cellulose blanks 13 having a higher basis weight at a first location originating from the first area than at a second location originating from the second area. A higher basis weight means more cellulose fibers per unit area of ​​the cellulose blank 13. The forming drum 15 may have three or more levels of perforation density, and / or the interface between two areas with different perforation densities may be an abrupt or smooth transition.

[0049] According to various embodiments, the second perforation density of the second area on the outer surface of the forming drum 15 is equal to 0, i.e., there are no perforations, and thus cellulose fibers do not adhere to the second area on the outer surface of the forming drum 15. Furthermore, a low perforation density in the second area on the outer surface of the forming drum 15 inevitably results in a large amount of cellulose fibers not adhering to the second area on the outer surface of the forming drum 15. The first and second areas may be provided on the enclosing surface of the forming drum 15. This forms a discontinuous cellulose blank 13, i.e., one with different basis weights at different locations. Thus, the basis weight is 0 at some locations and high at other locations. Each sheetlet of the discontinuous cellulose blank 13 may have a uniform basis weight or areas with different basis weights.

[0050] According to various embodiments, the outer surface of the forming drum 15 includes a main enveloping surface 64 and one or more recesses / internal growths 62 provided within the main enveloping surface 64 (see Figure 5). The recesses / internal growth 62 are suitable for producing continuous or discontinuous cellulose blanks 13 having locations / areas with different basis weights. Thus, a first area of ​​the forming drum 15 having a first perforation density is located in one or more recesses 62, forming continuous or discontinuous cellulose blanks 13 having a higher basis weight at locations originating from the first area than at locations originating from the second area. Locations of cellulose blanks emerging from internal growth 64 have a higher basis weight than locations of cellulose blanks emerging from the peripheral areas of the outer surface of the forming drum 15 without such internal growth.

[0051] Each recess 62 may include both a first area having a first perforation density and a second area having a second perforation density, and / or the recess may have different depths relative to the first and second areas. Preferably, the second area having the second perforation density is located on the main envelope surface 64, and the first area having the first perforation density is located within the recess.

[0052] In Figure 1, the forming cylinder 15 may be perforated in the internal growth area 62 and the main enclosing surface 64 surrounding the internal growth 62. An exemplary embodiment of the resulting continuous cellulose blank 13 may be similar to that shown in Figure 2. The lower portion of Figure 2 shows a top view of the cellulose blank 13, and the upper portion of Figure 2 shows a cross-sectional view of the same cellulose blank 13. This cross-sectional view is located in a plane perpendicular to the top surface of the cellulose blank 13 and perpendicular to the movement of the cellulose blank when it is attached to the support structure 8. The cellulose blank 13 emerging from the forming cylinder in Figure 1 may have an essentially flat base structure 34, on which cellulose fiber protrusions are attached to form a 3D structured cellulose blank with different basis weights. The protrusions 32 originate from recesses / internal growth within the forming cylinder / drum 15. In Figure 2, the cellulose blank is a continuous cellulose blank 13 having a 3D structure.

[0053] Referring now to Figure 3, Figure 3 schematically illustrates an alternative exemplary embodiment of the apparatus 100 of the present invention for dry-processing a rigid cellulose product having an essentially non-flat overall shape from cellulose raw material. The difference between Figure 3 and Figure 1 is the design of the forming cylinder / drum 15. In Figure 1, the forming drum 15 is configured to produce a continuous cellulose blank having areas of higher basis weight corresponding to internal growth within the forming drum 15. In Figure 3, the forming drum 15 is configured to produce a discontinuous cellulose blank, i.e., individual sheetlets 32 of unconnected cellulose blanks 13.

[0054] The forming drum 15 in Figure 3 may have perforations only within the internal growth to produce this discontinuous cellulose blank of individual sheetlets, i.e., a first area having a first perforation density and a second area having zero or minimal perforation density. Thereafter, not enough cellulose fibers accumulate in the second area to hold together the individual sheetlets of the cellulose blank. Loose cellulose fibers do not adhere to the forming drum 15 that does not have perforations. Perforations in the forming cylinder can provide a foundation for sheet growth while simultaneously removing excess air to the inside of the forming cylinder and away from the forming process. The areas of the forming drum without perforations may have a relatively smooth surface. When loose cellulose fibers come into contact with such a smooth surface that does not have the possibility of removing excess air, the cellulose fibers become very difficult to adhere to such areas of the forming drum 15, thereby forming individual sheetlets 32 of the cellulose blank 13 as shown in Figure 4. Figure 4 is an example of a discontinuous cellulose blank 13. In Figure 4, the sheetlets 32 are shown to be separated in both the axial and transverse directions when viewed from above. In an alternative embodiment, the sheetlets 32 may be formed in a strip / tile pattern in either the axial or transverse direction when viewed from above.

[0055] Figure 5 discloses an exemplary embodiment of the outer surface of a forming drum / cylinder 15. The forming cylinder comprises a plurality of internal growths 62 and a main enveloping surface 64 surrounding the recesses / internal growths 62. The forming drum 15 may have perforations only within the internal growths 62, only in the surrounding enveloping surface 64, or both in the recesses / internal growths 62 and the enveloping surface 64. The resulting shape of the cellulose blank 13 coming out of the forming drum 15 depends particularly on the shape and number of the recesses / internal growths, if perforations are provided in the forming drum 15.

[0056] Figure 6 schematically shows an alternative exemplary embodiment of the apparatus 100 of the present invention for dry-processing rigid cellulose products having an essentially non-flat overall shape from cellulose raw materials. The difference between Figure 6 and Figure 1 is the design of the press unit 12 and the forming tools 11a, 11b, i.e., the product forming unit 40.

[0057] According to Figure 1, the product forming unit 40 comprises a fixed press unit 12 having a single forming tool 11 for producing one or more three-dimensional products in a single mold / process. It will be understood that the apparatus according to Figure 1 may comprise parallel press units 12 and / or parallel forming tools 11 within a single press unit 12. In Figure 6, the product forming unit 40 is a continuous process, with female and male parts positioned on two rotational forming units 11a, 11b. The rotation of the forming units 11a, 11b may be synchronized with the supply of cellulose blank 13 into the product forming unit 40. The rotational forming units 11a, 11b may have multiple parallel shapes for forming three-dimensional products. The rotational forming units 11a, 11b may include multiple identical shapes for forming the same three-dimensional product. The rotational forming units 11a, 11b may include multiple different shapes for forming multiple different three-dimensional products. The rotation of the rotational forming units can advance the three-dimensional product from the press unit 12 and supply new cellulose blank into the press unit 12. It will be noted that product forming units 40 according to different embodiments are interchangeable without affecting the rest of the apparatus 100. As shown in Figure 6, a compression roll 10 is also shown downstream of the forming drum 15 and upstream of the product forming unit 40. The compression roll 10 is optional in the exemplary embodiments disclosed in Figures 1 and 3. The compression roll 10 may compress the air-filled cellulose blank 13 to at least half of its initial / uncompressed thickness. According to various exemplary embodiments, the compression roll 10 compresses the cellulose blank 13 to at least one-third of its initial / uncompressed thickness. Thereafter, the compressed cellulose blank 13 can be handled more easily after the cellulose blank forming unit 30, i.e., before the forming unit 40, up to the forming unit 40, and within the forming unit 40.

[0058] Referring specifically to Figures 7 to 10, which schematically disclose exemplary embodiments having a multi-stage cellulose blank forming unit 30, it will be noted that the upstream and downstream portions of the apparatus 100 described herein can be combined with the cellulose blank forming unit 30 shown in Figures 7 to 10.

[0059] The cellulose blank forming unit 30 includes two substeps, namely, one additional forming arrangement in addition to the forming drum 15 described above. According to Figure 7, the additional formation configuration is comprised of a tower forming unit 7 located upstream of the forming drum 15.

[0060] The separated cellulose fibers 6 are supplied into the tower forming unit 7 by at least one fan 4' positioned between the separation / decomposition unit 3 and the tower forming unit 7. The separated cellulose fibers 6 supplied into the tower forming unit 7 are drawn to the bottom by a vacuum / low-pressure vessel 5'. The tower forming unit 7 is positioned on a continuous support structure / web 8, on which the separated fibers 6 are arranged to form a cellulose blank 13. The vacuum / low-pressure vessel 5' is positioned directly below the tower forming unit 7 and below the support structure 8, so as to remove the air supplied into the tower forming unit 7 by an air removal device / fan 54'. As the continuous support structure 8 moves, a cellulose blank 13 of a predetermined thickness 34 and basis weight is positioned on the top surface of the support structure 8. The thickness and basis weight of the cellulose blank 13 are determined by combining the speed of the support structure 8 and the amount of fibers separated per unit volume of air in the tower forming unit 7.

[0061] The separated fibers 6 are also supplied onto the forming cylinder / drum 15 as described above. The forming drum 15 may be located downstream or upstream of the tower forming unit 7. For example, the forming drum 15 imparts continuous or discontinuous sheets of cellulose fibers having a variable basis weight to a uniform cellulose blank originating from the tower forming unit 7, as described above. The combined cellulose blank 13 has a planar / uniform cellulose blank 34 coming out of the tower forming unit 7 and a sheet of cellulose fibers coming out of the forming drum 15.

[0062] Therefore, the forming drum 15 may produce a continuous cellulose blank as shown in Figure 1, or a discontinuous cellulose blank as shown in Figure 3, so that it is added to the sheet of cellulose fibers coming out of the tower forming unit 7. According to the exemplary embodiment disclosed in Figure 7, the composition of the cellulose fibers from the tower forming unit 7 and the forming drum 15 is the same, since the cellulose fibers are supplied from one same separation unit 3. According to an alternative embodiment, as shown in Figure 9, the tower forming unit 7 is supplied with cellulose fibers separated from a first separation unit, and the forming drum 15 is supplied with cellulose fibers separated from a second separation unit. In such a case, as already discussed, the cellulose fibers from the first and second separation units may be different, i.e., they may be derived from different cellulose raw materials, have different fiber lengths, have different agents / additives, and so on.

[0063] Referring now to Figure 8, in contrast to the exemplary embodiment of Figure 7, the tower forming unit 7 is replaced with a second forming drum 15', which is preferably configured in line with the (first) forming drum 15.

[0064] Therefore, the second forming drum 15' has an outer surface including perforations, and the outer surface is configured to receive cellulose fibers from a certain amount of separated cellulose fibers transported by an airflow to form a cellulose blank 13. Furthermore, a second air removal device is placed inside the second forming drum 15', i.e., at least a portion of the air removal device 54' is placed inside the forming drum 15'. The second forming drum 15' may be configured as the (first) forming drum 15.

[0065] According to various embodiments, a second fan 4' for generating a cellulose fiber transport airflow is attached to a second forming drum 15'. A decomposition unit 3 is connected to the second fan 4', and a separate or identical decomposition unit acts on the (first) forming drum 15. Thus, the outer surface of the second forming drum 15' is configured to receive cellulose fibers from the amount of separated cellulose fibers transported by the airflow generated by the second fan 4' and to form a cellulose blank. Alternatively, one identical fan may be attached to both the (first) forming drum 15 and the second forming drum 15'. Or, an air removal device 54' may also perform the tasks of the fan 4', thereby becoming a single device that generates the cellulose fiber transport airflow attached to the second forming drum 15'.

[0066] In the example shown in Figure 8, the (first) forming drum 15 is located downstream of the second forming drum 15', and the angular spacing 5 of the forming drums 15 extends from the position where cellulose fibers are added from the fan 4 to the position where the cellulose blank 13 is received by the support structure 8. The (first) forming drum 15 rotates counterclockwise, and the second forming drum 15' rotates clockwise, and these forming drums are positioned adjacent to each other such that the cellulose fibers of the two drums contact at one point / boundary surface. In Figure 8, the (first) forming drum 15 forms a discontinuous sheetlet of cellulose blank, and the second forming drum 15' also forms a discontinuous sheetlet of cellulose blank in the same manner as described above in relation to the (first) forming drum 15. The angular spacing 5' of the second forming drum 15' ends at the position / boundary surface where the cellulose fibers of the two drums contact, and the angular spacing 5 of the (first) forming drum 15 becomes active at the said position / boundary surface. As a result, the cellulose fibers on the outer surface of the second forming drum 15' are transferred to the outer surface of the (first) forming drum 15, and the combined discontinuous cellulose blank 13 is subsequently received by the support structure 8. Figure 8 discloses the use of a compression roll 10 located downstream of the two drums and upstream of the product forming unit 40. Below the support structure / web 8 are means 54' for removing air so that the cellulose blank 13 produced by the forming drums is fixed to the moving support structure 8. This ensures the orientation of the sheetlet of the cellulose blank 13. This also applies to embodiments of other figures disclosing the apparatus 100.

[0067] According to an alternative exemplary embodiment, the (first) forming drum 15 is located upstream of the second forming drum 15'. The second forming drum 15' can produce a continuous cellulose blank on its outer surface, and the continuous cellulose blank on the second forming drum 15' may be uniform. Then, as described above, a sheetlet of cellulose blank is added from the (first) forming drum 15 to the second forming drum 15', and thereafter, a cellulose blank 13 having a variable basis weight is received by the support structure 8.

[0068] Referring next to Figure 9, Figure 9 shows the use of a second decomposition unit 3' associated with a second forming drum 15'. In such cases, as already discussed, the cellulose fibers from the first decomposition unit 3 and the cellulose fibers from the second decomposition unit 3' may be different in order to further adjust the properties of the final cellulose product 14. It will be noted that when different decomposition units are associated with different forming drums / units, these decomposition units may also be configured to provide the same type of cellulose fibers. Different layers of the cellulose blank 13 may have different properties by adding different additives / agents to different cellulose raw materials, thereby allowing for very precise control of the penetration depth of the additives in the final cellulose product 14.

[0069] Referring next to Figure 10, the cellulose blank forming unit 30 includes an alternative type of compression roll 10. The compression roll 10 is also configured to remove continuous or discontinuous cellulose blank 13 from the (first) forming drum 15 and transfer it to the support structure 8 as the cellulose blank 13 is compressed.

[0070] Therefore, the compression roll 10 is composed of one or more compression drums, with perforation and air removal means arranged inside each drum. Thereafter, the cellulose blank 13 formed on the forming drum 15 is transferred to the first compression drum at the position / boundary where the angular boundary surface 5 of the forming drum 15 ends, and the corresponding angular boundary surface of the first compression drum becomes active. The transfer from one drum to the other is the same throughout the apparatus 100, i.e., one angular interval ends (pressurization ends) and the next angular interval becomes active (pressurization becomes active). The second compression drum is located in close proximity to the first compression drum, and at the position / boundary where these compression drums meet, continuous or discontinuous cellulose blanks 13 are compressed and transferred from the first compression drum to the second compression drum. The compressed cellulose blank may be transferred to additional compression drums before the cellulose blank is received by the support structure 8, during which the cellulose blank may be further compressed.

[0071] According to the alternative embodiment, the second compression drum is replaced with a compression roll, and the cellulose blank 13 is compressed between the first compression drum and such a compression roll, and the cellulose blank is not transferred from the first compression drum. The compressed cellulose blank is then transferred from the first compression drum to the support structure 8.

[0072] According to various exemplary embodiments, an intermediate product may be manufactured for the dry production of at least one rigid cellulose product 14 having an essentially non-flat overall shape. The intermediate product consists of a continuous or discontinuous cellulose blank 13 having a first position and a second position, the first position having a higher basis weight than the second position. The basis weight of the second position may be 0, as discussed above. Such an intermediate product may be supplied, for example, in the form of individual sheets or on a roll. The first position of the cellulose blank, i.e., the intermediate product, overlaps with the crack-prone and / or stiffened areas of the subsequent rigid cellulose product 14 having an essentially non-flat overall shape.

[0073] A rigid cellulose product 14 having an essentially non-flat overall shape may be produced from an intermediate product, i.e., a cellulose blank 13, by pressing in a product forming unit 40, where the maximum basis weight of the rigid cellulose product 14 is less than the maximum basis weight of the cellulose blank 13 at a first position. Thus, the cellulose fibers of the cellulose blank 13, the intermediate product, are dispersed again during the pressing step in response to the non-flat overall shape of the final cellulose product 14.

[0074] The circumferential velocity within the separation unit may be in the range of 50 to 150 m / sec. In various exemplary embodiments, the circumferential velocity may be in the range of 90 to 150 m / sec. In various exemplary embodiments, the size of the cellulose fibers may be 2 mm, and the amount of fiber per unit volume of air may be 9 to 12 g of water / 1 kg of air and 100 g of fiber / 1 m³ of air. The support structure, continuous forming cylinder, and / or continuous web may have a width of 20 to 100 cm. In various exemplary embodiments, the width is 30 to 70 cm. The sheet of cellulose fiber 13 may have a weight of 200 to 2000 g / m². The pressure within the pressure unit may be in the range of 40 to 10000 N / cm².

[0075] For example, a discontinuous cellulose blank is formed on the outer surface of a forming drum 15, with each sheetlet measuring approximately 20 cm × 30 cm. To obtain a final cellulose product with a thickness of 0.5 mm, the basis weight is approximately 600 g / m2 in the first area and 0 g / m2 in the second area, i.e., between the sheetlets of the discontinuous cellulose blank. This process can produce 2500 sheetlets per hour, with each sheetlet weighing 36 g, i.e., 90 kg of cellulose raw material per hour. To obtain approximately 500 g of cellulose fibers per cubic meter of air, the required airflow is 180 m3 of air per hour. To accumulate sufficient cellulose fibers in each sheetlet of the cellulose blank, the air velocity on the outer surface of the forming drum 15 is approximately 3-5 m / sec.

[0076] The humidity of the airflow should be in the range of 9 to 12 g per kg of air, preferably 11 g per kg of air (equivalent to 14.3 g per m³ of air). To obtain the required level, different amounts of water must be added depending on the humidity of the ambient air. The humidity of the ambient air should preferably be in the range of 55 to 65% RH at 20 degrees Celsius.

[0077] For example, a discontinuous cellulose blank is formed using two forming drums 15 and 15'. A first circular cellulose blank is formed on the outer surface of the (first) forming drum 15, with a diameter of 40 cm and a basis weight of approximately 500 g / m2, and a second circular cellulose blank is formed on the outer surface of the second forming drum 15', with a diameter of 20 cm and a basis weight of approximately 200 g / m2. This process can produce 2500 sheetlets per hour, with each sheetlet weighing 63 + 6 = 69 g, i.e., 172.5 kg of cellulose raw material per hour. To obtain approximately 500 g of cellulose fiber per cubic meter of air, the required airflow is 345 m3 of air per hour.

[0078] Executable modifications of the present invention The present invention is not limited to the embodiments described above as shown in the drawings, which are primarily for illustrative purposes. This patent application is intended to encompass all modifications and variations of the preferred embodiments described herein, and therefore the present invention is defined by the expression of the appended claims and its equivalents. Thus, the apparatus may be modified in any way within the scope of the appended claims.

[0079] Throughout this specification and the subsequent claims, unless otherwise required by context, the word “comprise” and its variations such as “comprises” or “comprising” will be understood to indicate the inclusion of the integer or step or group of integers or group of steps described, rather than the exclusion of any other integer or step or group of integers or group of steps.

[0080] Therefore, it can be pointed out that even when it is not explicitly stated that features from a particular embodiment may be combined with features from another embodiment, if such combination is possible, it should be considered obvious. Specific embodiments of the present invention are as follows. [Aspect 1] An apparatus (100) for dry manufacturing a rigid cellulose product (14) having an essentially non-flat overall shape, - A decomposition unit (3) for providing a certain amount of cellulose fibers (6) separated from a cellulose raw material (1), - Cellulose blank forming unit (30), - A dispenser for guiding the cellulose fiber transport airflow from the decomposition unit (3), - A forming drum (15) having an outer surface including perforations, the outer surface being configured to receive cellulose fibers from the amount of separated cellulose fibers transported by the airflow through the dispenser, and to form a cellulose blank (13), - An air removal device (54) disposed within the forming drum (15), and - A cellulose blank forming unit (30) comprising a support structure (8) for receiving the cellulose blank (13) formed on the forming drum (15), - A product forming unit (40) for producing a rigid cellulose product (14) having an essentially non-flat overall shape from a cellulose blank (13) by pressing, and Equipped with, Apparatus (100) characterized in that the outer surface of the forming drum (15) includes a first area having a first perforation density and a second area having a second perforation density less than the first area, and forms a continuous or discontinuous cellulose blank (13) having a higher basis weight at a first position originating from the first area than at a second position originating from the second area. [Aspect 2] The apparatus (100) according to embodiment 1, wherein the second perforation density of the second area on the outer surface of the forming drum (15) is equal to 0. [Aspect 3] Apparatus (100) according to embodiment 1 or 2, wherein the outer surface of the forming drum (15) includes a main enclosing surface (64) and one or more recesses (62) provided in the main enclosing surface (64), and the first area having a first perforation density is located in the one or more recesses (62), forming a continuous or discontinuous cellulose blank (13) having a higher basis weight at the position originating from the first area than at the position originating from the second area. [Aspect 4] The apparatus (100) according to embodiment 3, wherein the second area having a second perforation density is located on the main enclosing surface (64) and forms a continuous or discontinuous cellulose blank (13) having a higher basis weight at the position originating from the first area than at the position originating from the second area. [Aspect 5] The cellulose blank forming unit (30) - A second forming drum (15') having an outer surface including perforations, the outer surface being configured to receive cellulose fibers from a certain amount of separated cellulose fibers transported by an airflow and to form a cellulose blank (13), - A second air removal device (54') is located inside the second forming drum (15') and The apparatus (100) according to any one of embodiments 1 to 4, comprising: [Aspect 6] The cellulose blank forming unit (30) - A second fan (4') for generating a cellulose fiber transport airflow is provided, and a disassembly unit (3, 3') is connected to the second fan (4'), The apparatus (100) according to embodiment 5, wherein the outer surface of the second forming drum (15') is configured to receive cellulose fibers from the amount of separated cellulose fibers transported by the airflow generated by the second fan (4') to form a cellulose blank (13). [Aspect 7] The apparatus (100) according to any one of embodiments 1 to 6, wherein the product forming unit (40) comprises a molding tool (11) for producing the rigid cellulose product having an essentially non-flat overall shape from the continuous or discontinuous cellulose blank (13). [Aspect 8] The apparatus (100) according to any one of embodiments 1 to 7, wherein the cellulose blank forming unit (30) is further comprising a compression roll (10) downstream of the forming drum (15) for compressing the continuous or discontinuous cellulose blank (13). [Aspect 9] A dry manufacturing method for a rigid cellulose product (14) having an essentially non-flat overall shape, - A step of providing a certain amount of separated cellulose fibers (6) by breaking down a cellulose raw material (1), - A step of transporting the separated cellulose fibers (6) to the outer surface of a forming drum (15) by airflow, wherein the outer surface of the forming drum (15) includes perforations, - A step of forming a continuous or discontinuous cellulose blank (13) on the outer surface of the forming drum (15) by removing air from the inside of the forming drum (15) in order to temporarily hold the cellulose fibers (6) on the outer surface of the forming drum (15), - A step of transferring the continuous or discontinuous cellulose blank (13) from the forming drum (15) to the support structure (8), - A step of producing a rigid cellulose product (14) having an essentially non-flat overall shape by pressing the continuous or discontinuous cellulose blank (13) in a product forming unit (40) Includes, The continuous or discontinuous cellulose blank (13) includes a first position and a second position, The first position has a higher basis weight than the second position, A method wherein the first position is derived from a first area on the outer surface of the forming drum (15) having a first perforation density, and the second position is derived from a second area on the outer surface of the forming drum (15) having a second perforation density less than the first perforation density. [Aspect 10] The step of forming a continuous or discontinuous cellulose blank (13) on the outer surface of the forming drum (15) by removing air from the inside of the forming drum (15) in order to temporarily hold the cellulose fibers (6) on the outer surface of the forming drum (15), - The method according to embodiment 9, comprising a substep of transferring additional cellulose fibers (6) from the outer surface of a second forming drum (15') to the cellulose fibers transported by the airflow to the outer surface of the forming drum (15). [Aspect 11] The method according to embodiment 9 or 10, wherein the continuous or discontinuous cellulose blank (13) is compressed downstream of the forming drum (15). [Aspect 12] A continuous or discontinuous cellulose blank (13) which is an intermediate product for dry manufacturing of at least one rigid cellulose product (14) having an essentially non-flat overall shape, formed by a forming drum (15) including a first position and a second position, wherein the first position has a higher basis weight than the second position. [Aspect 13] A continuous or discontinuous cellulose blank (13) according to embodiment 12, wherein the first position of the cellulose blank (13) overlaps with a crack-prone area and / or an area with increased rigidity of the subsequent rigid cellulose product (14) having an essentially non-flat overall shape. [Aspect 14] A rigid cellulose product (14) having an essentially non-flat overall shape, which is produced by pressing the continuous or discontinuous cellulose blank (13) described in embodiment 12 within a product forming unit (40), wherein the maximum basis weight of the rigid cellulose product (14) is less than the maximum basis weight of the cellulose blank (13) at the first position. [Aspect 15] A rigid cellulose product (14) having an essentially non-flat overall shape according to embodiment 14, wherein the cellulose product (14) comprises cellulose fibers from a cellulose raw material (1) composed of unused cellulose fibers and / or recycled cellulose fibers, wherein the cellulose fibers are derived from wood pulp such as kraft pulp, sulfite pulp, mechanical pulp, thermomechanical pulp, chemically treated mechanical pulp, chemothermetic pulp, and / or non-wood pulp such as bagasse, bamboo, Manila hemp, hemp, flax, and cotton. [Explanation of symbols]

[0081] 1. Raw materials (cellulose) 1a Winded pulp or paper 1b veil 1c sheet 2. Chemical Injection Unit 3. Hammer mill (separation unit) 4. Fan (4, 4') 5. Vacuum / low-pressure vessel (5, 5') 6. Separated fibers 7. Tower Forming Unit 8. Continuous or discontinuous support structures / webs 9. Chemical Injection Unit a.9a b.9b c.9c 10. Compression Roll / Drum 11. Molding Tools 12. Press Unit 13. Cellulose Blank 14. Final cellulose products having an essentially non-flat overall shape. 15. Forming cylinder / drum (15, 15') 16. Preheating Unit 17. Humidifier Unit a.17a b.17b c.17c 18. Shredder (separation unit) and injection unit 30. Cellulose Blank / Sheet Forming Unit 32. Cellulose fiber protrusions / sheetlets 34. Planar structure / basal structure of cellulose blank 40. Product Forming Unit 54. Air removal device (54, 54') 62. Internal growth / recess 64. Enveloping surface surrounding the recess 100. Apparatus for dry manufacturing of rigid cellulose products

Claims

1. An apparatus (100) for dry manufacturing a rigid cellulose product (14) having an essentially non-flat overall shape, - A decomposition unit (3) for providing a certain amount of cellulose fibers (6) separated from a cellulose raw material (1), - Cellulose blank forming unit (30), - A dispenser for guiding the cellulose fiber transport airflow from the decomposition unit (3), - A forming drum (15) having an outer surface including perforations, the outer surface being configured to receive cellulose fibers from the amount of separated cellulose fibers transported by the airflow through the dispenser and to form a cellulose blank (13), - An air removal device (54) disposed within the forming drum (15), and - A cellulose blank forming unit (30) comprising a support structure (8) for receiving the cellulose blank (13) formed on the forming drum (15), - A product forming unit (40) for producing a rigid cellulose product (14) having an essentially non-flat overall shape from the cellulose blank (13) by pressing, and Equipped with, The apparatus (100) is characterized in that the outer surface of the forming drum (15) includes a first area having a first perforation density and a second area having a second perforation density less than the first area, and a continuous or discontinuous cellulose blank (13) is formed having a higher basis weight at a first position originating from the first area than at a second position originating from the second area.

2. The apparatus (100) according to claim 1, wherein the second perforation density of the second area on the outer surface of the forming drum (15) is equal to 0.

3. The apparatus (100) according to claim 1 or 2, wherein the outer surface of the forming drum (15) includes a main enclosing surface (64) and one or more recesses (62) provided in the main enclosing surface (64), and the first area having a first perforation density is located in the one or more recesses (62), and a continuous or discontinuous cellulose blank (13) is formed having a higher basis weight at the position originating from the first area than at the position originating from the second area.

4. The apparatus (100) according to claim 3, wherein the second area having a second perforation density is located on the main enclosing surface (64) and forms a continuous or discontinuous cellulose blank (13) having a higher basis weight at the position originating from the first area than at the position originating from the second area.

5. The cellulose blank forming unit (30) - A second forming drum (15') having an outer surface including perforations, the outer surface being configured to receive cellulose fibers from a certain amount of separated cellulose fibers transported by an airflow and to form a cellulose blank (13), - A second air removal device (54') is disposed within the second forming drum (15') and The apparatus (100) according to any one of claims 1 to 4, comprising:

6. The cellulose blank forming unit (30) - A first fan (4) and a second fan (4') for generating a cellulose fiber transport airflow are provided, and disassembly units (3, 3') are connected to the first fan (4) and the second fan (4'), The apparatus (100) according to claim 5, wherein the outer surface of the second forming drum (15') is configured to receive cellulose fibers from the amount of separated cellulose fibers transported by the airflow generated by the second fan (4') to form a cellulose blank (13).

7. The apparatus (100) according to any one of claims 1 to 6, wherein the product forming unit (40) comprises a molding tool (11) for producing the rigid cellulose product having an essentially non-flat overall shape from the continuous or discontinuous cellulose blank (13).

8. The apparatus (100) according to any one of claims 1 to 7, wherein the cellulose blank forming unit (30) comprises a compression roll (10) downstream of the forming drum (15) for compressing the continuous or discontinuous cellulose blank (13).

9. A dry manufacturing method for a rigid cellulose product (14) having an essentially non-flat overall shape, - A step of providing a certain amount of separated cellulose fibers (6) by decomposing a cellulose raw material (1), - A step of transporting the separated cellulose fibers (6) to the outer surface of a forming drum (15) by airflow, wherein the outer surface of the forming drum (15) includes perforations, - A step of forming a continuous or discontinuous cellulose blank (13) on the outer surface of the forming drum (15) by removing air from the inside of the forming drum (15) in order to temporarily hold the cellulose fibers (6) on the outer surface of the forming drum (15), - A step of transferring the continuous or discontinuous cellulose blank (13) from the forming drum (15) to the support structure (8), - A step of producing a rigid cellulose product (14) having an essentially non-flat overall shape by pressing the continuous or discontinuous cellulose blank (13) in a product forming unit (40) Includes, The continuous or discontinuous cellulose blank (13) includes a first position and a second position, The first position has a higher basis weight than the second position, A method wherein the first position is derived from a first area on the outer surface of the forming drum (15) having a first perforation density, and the second position is derived from a second area on the outer surface of the forming drum (15) having a second perforation density smaller than the first perforation density.

10. The step of forming a continuous or discontinuous cellulose blank (13) on the outer surface of the forming drum (15) by removing air from the inside of the forming drum (15) in order to temporarily hold the cellulose fibers (6) on the outer surface of the forming drum (15), The method according to claim 9, further comprising the substep of transferring additional cellulose fibers (6) from the outer surface of a second forming drum (15') to the cellulose fibers transported to the outer surface of the forming drum (15) by the airflow.

11. The method according to claim 9 or 10, wherein the continuous or discontinuous cellulose blank (13) is compressed downstream of the forming drum (15).

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