Product forming unit, cellulose product toggle pressing module and method for forming non-flat cellulose products from an air-formed cellulose blank structure

Abstract

This invention discloses an article forming unit (U) for manufacturing a non-flat cellulose article (1) from an air-formed cellulose preform structure (2). The article forming unit (U) includes a preform dry forming module (4) having a movable forming line (4c), an elbow pressing module (6) having an elbow press (6a) and a forming die (3), and an electronic control system (6h) operably connected to the forming line (4c) and the elbow press (6a). The preform dry forming module (4) is configured to air-form the cellulose preform structure (2) onto the forming line (4c). The elbow press (6a) includes a pressing member (6d) movably arranged along a pressing direction, an elbow mechanism (6e) driven to the pressing member (6d), and a pressing actuator configuration (6f) driven to the elbow mechanism (6e). The molding die (3) includes a movable first die portion (3a) and a second die portion (3b) attached to one of the pressing members (6d). The electronic control system (6h) is configured to control the operation of the pressing actuator configuration (6f) to perform a pressing operation, which involves driving the pressing member (6d) in the pressing direction by means of the toggle mechanism (6e), thereby forming the non-flat cellulose article from the air-formed cellulose preform structure by pressing the first die portion (3a) against the second die portion (3b). The electronic control system (6h) is further configured to intermittently feed the forming line (4c) between subsequent pressing operations.

Description

Technical Field

[0001] This invention relates to a toggle-joint pressing mold for cellulose products, used for molding non-flat cellulose products from an air-formed cellulose preform structure. Further, this invention relates to a method for molding non-flat cellulose products from an air-formed cellulose preform structure using a toggle-joint pressing mold for cellulose products.

[0002] The elbow pressing module for cellulose products according to the present invention will be described primarily with respect to examples such as cellulose product molding units and cellulose preform air forming modules having integrated fiber separation modules. However, the elbow pressing module for cellulose products and its associated methods of use are not limited to this specific implementation and can be implemented and used in many other types of cellulose product manufacturing systems. Prior Technology

[0003] Cellulose fibers are commonly used as raw materials for the production or manufacture of articles. Articles made from cellulose fibers can be used in many different situations where sustainable products are required. Cellulose fibers can be made into a wide variety of articles, and many examples include disposable plates and cups, tableware, lids, bottle caps, coffee pods, and packaging materials.

[0004] Molding dies are commonly used in the manufacture of cellulose products from cellulose fiber raw materials, and cellulose products are typically wet-formed. The material commonly used for wet-formed cellulose fiber products is wet-molded pulp. Wet-molded pulp has the advantage of being considered a sustainable packaging material because it is made from biomaterials and can be recycled after use. Therefore, wet-molded pulp is rapidly gaining popularity for various applications. Wet-molded pulp products are typically formed by immersing a suction molding die into a liquid or semi-liquid pulp suspension or slurry containing cellulose fibers, and by applying suction, the fibers deposit onto the molding die to form a pulp body with the desired product shape. For all wet-molding technologies, drying of the wet-molded product is required, which is an extremely time-consuming and energy-intensive part of the production process. The aesthetic, chemical, and mechanical properties of cellulose products are increasingly demanding, and due to the nature of wet-formed cellulose products, the freedom of mechanical strength, flexibility, material thickness, and chemical properties is limited. In the wet molding process, it is also difficult to control the mechanical properties of the product with high precision.

[0005] One development in the production of cellulose products involves forming cellulose fibers in a dry forming process, eliminating the need for wet forming. This replaces the forming of cellulose products from liquid or semi-liquid pulp suspensions or slurries, utilizing air-formed cellulose preform structures. The air-formed cellulose preform structure is inserted into a molding die, and during the forming of the cellulose product, the cellulose preform structure is subjected to high forming pressure and high forming temperature within the die.

[0006] Cellulose products can be manufactured by air-forming cellulose preform structures using compression molding in a production line or product forming unit. Manufacturing equipment typically includes pressing modules, which contain forming molds. Other modules and components are configured to connect to the pressing modules, such as, for example, feed modules and preform dry forming modules. Pressing modules are typically high-capacity pressing modules, such as large hydraulic or servo-powered pressing machines, which can be used to form other materials (such as steel plates) because these modules can be used as stand-alone, off-the-shelf machines.

[0007] One drawback of using standard press modules developed for general purposes is the high cost typically associated with conventional high-capacity hydraulic or servo-powered presses, as well as the problems caused by their larger size and weight in terms of transportation, installation, maintenance, and factory size.

[0008] Furthermore, customers who typically invest in cellulosic product molding units are called converters, and they typically lack or have very little of the engineering skills required to develop and integrate the modules needed for a complete cellulosic product molding unit. Therefore, converters expect to purchase complete, fully integrated, standardized production molding units that are easier to transport, install, and operate.

[0009] Therefore, there is a need for a low-cost, compact, and lightweight cellulose article pressing mold for molding non-flat cellulose articles from air-formed cellulose preform structures, and a method for molding non-flat cellulose articles from air-formed cellulose preform structures using such a cellulose article pressing mold. There is also a need for cellulose article pressing molds that enable the development and manufacture of low-cost, compact, fully integrated, and standardized cellulose article molding units that are easy to transport, install, and operate. Summary of the Invention

[0010] One object of the present invention is to provide a cellulose article pressing mold for molding non-flat cellulose articles from air-formed cellulose preform structures, and a related method for molding non-flat cellulose articles from air-formed cellulose using such a pressing mold, wherein the previously mentioned problems are avoided. This object is achieved at least in part by the features of the independent claim.

[0011] According to a first aspect of the present invention, a product molding unit is provided for manufacturing non-flat cellulose articles from an air-formed cellulose preform structure. The product forming unit includes: a blank dry forming module with a movable forming wire, an elbow pressing module with an elbow press and a forming die, and an electronic control system operably connected to the forming wire and the elbow press; wherein the blank dry forming module is configured to air-form the cellulose blank structure onto the forming wire; wherein the elbow press includes a pressing member movably configured along the pressing direction, an elbow mechanism driven to the pressing member, and a pressing actuator configuration driven to the elbow mechanism; wherein the forming die includes a movable first die portion and a second die portion attached to the pressing member; wherein the electronic control system is configured to control the operation of the pressing actuator configuration to perform a pressing operation, which involves driving the pressing member along the pressing direction by means of the elbow mechanism, and thereby forming a non-flat cellulose product by pressing the first die portion against the second die portion of the air-formed cellulose blank structure; and wherein the electronic control system is further configured to intermittently feed the forming wire between subsequent pressing operations.

[0012] According to a second aspect of the present invention, a method is provided for molding a non-flat cellulose article from an air-formed cellulose preform structure in an article forming unit. The article forming unit includes a preform dry forming module with a movable forming line, an elbow pressing module with an elbow press and a forming die, and an electronic control system operably connected to the forming line and the elbow pressing module. The elbow press includes a pressing member movably arranged along the pressing direction, an elbow mechanism driven to the pressing member, and a pressing actuator driven to the elbow mechanism. The forming die includes a movable first die portion and a second die portion attached to the pressing member. The method includes: air-forming a cellulose preform structure onto a forming line using a preform dry forming module; feeding the air-formed cellulose preform structure into a pressing area defined by spaced-apart first and second mold portions; controlling the operation of a pressing actuator assembly to perform a pressing operation using an electronic control system, which involves driving a pressing member along the pressing direction using a toggle mechanism, thereby forming a non-flat cellulose article from the air-formed cellulose preform structure by pressing the first mold portion against the second mold portion; and controlling the operation of the forming line using an electronic control system to intermittently feed the forming line between subsequent pressing operations.

[0013] Toggle clamps are well-known in the field of injection molding, where, for example, liquid plastic material is injected under high pressure into a mold cavity formed by a closed mold. In the field of injection molding, the purpose of a toggle clamp is simply to close the injection mold portion and apply sufficient clamping force to prevent the mold portion from separating due to the injection pressure within the mold.

[0014] However, toggle mechanisms are not commonly used in compression molding applications, where pressure level is typically a relevant parameter that must be controlled with a certain degree of accuracy. This is partly because the exponential amplification characteristic of the toggle mechanism makes controlling the pressing force more complex, and partly because the resulting pressing force cannot be easily determined with good accuracy. For example, when the toggle mechanism is close to the force equilibrium position, the pressing force generated by the pressing actuator on the toggle mechanism is close to zero, thus making the pressing force of the pressing actuator less useful for determining the pressing force.

[0015] On the other hand, compared to conventional high-capacity hydraulic or servo presses, toggle presses have the advantages of being relatively compact and low-cost due to their lower input pressing force requirements. In other words, relatively small-capacity actuators, such as small-capacity hydraulic or pneumatic linear actuators, i.e., cylinder-piston configurations, or low-power electric motor-driven ball screw linear actuators, may be sufficient to drive the toggle mechanism and thus generate significantly larger pressing forces.

[0016] Furthermore, compared to conventional high-capacity hydraulic or servo presses, toggle presses possess inherently highly advantageous speed-force characteristics that significantly reduce cycle time in the forming process of cellulose products. Specifically, the inherent force amplification characteristic of the toggle mechanism causes the pressing member to move relatively fast during the initial cycle time (starting from the standby position), while the speed gradually decreases as the toggle mechanism approaches its maximum stroke, which facilitates an increase in maximum pressing force. Therefore, the initial movement of the pressing member is associated with high speed and lower maximum pressing force, while the movement of the pressing member during the actual pressing action is associated with low speed and higher maximum pressing force.

[0017] Furthermore, by configuring the electronic control system to intermittently feed the forming line between subsequent pressing operations, the need for relatively large, complex, and expensive buffer devices in the area between the blank dry forming module and the pressing module is eliminated, thereby further contributing to reducing the total cost of the product forming unit.

[0018] Furthermore, the compact size and low weight of the toggle press enable the development of extremely compact, complete, fully integrated, and standardized cellulosic product molding units that are easy to transport, install, and operate. The low cost of the toggle press also helps to keep the total cost of the cellulosic product molding unit at a low level.

[0019] Other advantages are achieved by implementing one or more features of the supplementary claims. For example, in some specific examples that can be combined with any or more of the above specific examples, such pressing operations involve driving the pressing member in the pressing direction by setting the toggle mechanism to its maximum extended operating position (i.e., aligning the first and second linkage members of the toggle mechanism). This simplifies the control of the actuator configuration used to drive the toggle mechanism, as control can be performed using, for example, the position of the pressing member or similarly easily detectable parameters as feedback signals. Furthermore, when operating in the operating area of ​​the aligned linkage members of the toggle press, the target pressing force is achieved relatively easily and robustly compared to, for example, operating near the asymptotic operating area associated with the operating area of ​​the non-aligned linkage members of the toggle press.

[0020] In some specific examples that can be combined with any or more of the above specific examples, the toggle press is installed or configured such that the pressing direction of the pressing member is primarily horizontal, specifically within 20 degrees of the horizontal, and more specifically parallel to the horizontal. The primary horizontal orientation of the toggle press enables a lower build-up height for the cellulose product molding unit and a non-vertical material flow for the continuously air-formed cellulose preform structure from the preform dry forming module to the pressing module. This non-vertical material flow, such as the routing of the continuously air-formed cellulose preform structure along a first direction (e.g., upward) and subsequently along a second direction (e.g., downward), typically enables the development and manufacture of more compact cellulose product molding units. Since the web of cellulose fiber material is typically supplied to the pressing module at approximately right angles to the pressing direction of the pressing module, the primary horizontal orientation of the toggle press is typically associated with a primarily vertical supply flow for the cellulose preform structure. Therefore, it is clear that a primarily horizontally configured pressing module height is advantageous when developing compact cellulose product molding units that allow non-linear material flow from the preform dry forming module to the pressing module in air-formed cellulose preform structures.

[0021] In some specific examples that can be combined with any or more of the above specific examples, the electronic control system is configured to intermittently feed the forming line between subsequent pressing operations, such that the forming line operates periodically at a relatively high speed during the time period between subsequent pressing operations and at a relatively low speed or zero speed during the time period concurrent with the pressing operation. This eliminates the need for relatively large, complex, and expensive buffer devices in the area between the blank dry forming module and the pressing module, thereby further contributing to a reduction in the overall cost of the product forming unit.

[0022] In some specific examples that can be combined with any or more of the above specific examples, the electronic control system is configured for the synchronous operation of the forming line and the toggle press, such that the forming line operates or at a relatively high speed during the time the toggle press is in a non-pressing state, and that the forming line is stationary or operates at a relatively low speed during the time the toggle press is in a pressing state. Therefore, the need for relatively large, complex, and expensive buffer devices in the area between the blank dry forming module and the pressing module is reduced, thereby further contributing to a reduction in the overall cost of the product forming unit.

[0023] In some specific examples that can be combined with any or more of the above specific examples, the electronic control system is configured to control the operation of the forming line and the toggle press, such that the feed rate of the forming line, specifically, during a complete pressing cycle, is equal to or at least substantially equal to the feed rate of the air-formed cellulose preform structure entering the forming die. Therefore, the need for relatively large, complex, and expensive buffer devices in the area between the preform dry forming module and the pressing module is eliminated, thereby further contributing to a reduction in the overall cost of the product forming unit.

[0024] In some specific examples that can be combined with any or more of the above specific examples, the product forming unit does not have a buffer module configured between the blank dry forming module and the toggle pressing module. The omission of the buffer module makes the product forming unit more cost-effective.

[0025] In some specific examples that can be combined with any or more of the above-described specific examples, the toggle press further includes: a pressure indication configuration; an adjustment mechanism for adjusting the distance between the first mold portion and the second mold portion along the pressing direction while keeping the toggle mechanism in a non-moving operating state; and an adjustment actuator configuration configured to drive the adjustment mechanism, wherein an electronic control system is operably connected to the pressure indication configuration and configured to control the operation of the adjustment actuator configuration based on pressure indication feedback information received from the pressure indication configuration. Thus, the operating position of the toggle press can be adjusted to better match and / or adapt to the specific characteristics of the cellulose preform structure and the shape of the molding die.

[0026] In some specific examples that can be combined with any or more of the above specific examples, the electronic control system is configured to control the operation of an adjusting actuator configuration for adjusting the distance between the first and second die portions during a time interval between consecutive pressing actions, such that the pressing member provides a compressive force closer to a predetermined target pressing force during the next pressing cycle. Thus, the operating position of the toggle press can be adjusted to better match and / or adapt to the specific characteristics of the cellulose preform structure and the shape of the molding die.

[0027] In some specific examples that can be combined with any or more of the above specific examples, the pressure indication configuration includes one or more of the following sensors: a load cell, a deformation sensor, or a strain gauge force sensor, wherein the one or more sensors are located at or within the forming mold, or on the toggle mechanism, or between the toggle mechanism and the rear structure of the rigid frame of the toggle press, or between the toggle mechanism and the forming mold, or at the rigid frame structure of the toggle press, or at the tie rod of the intermediate linear guide configuration of the toggle press. Thus, the reliability and accuracy of the obtained pressure estimate can be determined.

[0028] In some specific examples that can be combined with any or more of the above-described specific examples, the toggle press further includes a front structure and a rear structure, wherein the toggle mechanism is connected to the rear structure, wherein the second mold portion is attached to the front structure, and wherein a mechanical adjustment mechanism allows adjustment of the distance between the front and rear structures along the pressing direction, so as to allow adjustment of the distance between the first and second mold portions while the toggle mechanism is in a non-moving operating state. This achieves a compact and cost-effective pressing module.

[0029] In some specific examples that can be combined with any or more of the above-described specific examples, each of the first and second mold portions includes a main rigid plate-like body having a surface configured to face the other mold portion, and at least one pressing surface defining one or more molding cavities for molding cellulose articles, and having or not having additional fine components, such as spring-loaded cutting devices and / or mold alignment devices or the like, wherein the surfaces of the main rigid plate-like bodies of the first and second mold forming portions are not in direct contact with each other during the pressing cycle. Thus, the molding die can be used to press and mold non-flat cellulose articles at a certain molding pressure without creating unwanted interference between the surfaces.

[0030] In some specific examples that can be combined with any or more of the above specific examples, the molding die is configured to mold cellulose articles from a cellulose preform structure by heating the cellulose preform structure to a molding temperature in the range of 100-300°C and pressing the cellulose preform structure with a molding pressure in the range of 1-100 MPa (preferably 4-20 MPa). These parameters provide efficient molding of cellulose articles, in which strong hydrogen bonds are formed.

[0031] In some specific examples that can be combined with any or more of the above-described specific examples, the preform dry forming module further includes a grinding mill and a forming chamber, wherein the forming line is configured to connect to the forming chamber, wherein the grinding mill is configured to separate fiber from cellulose raw material, and wherein the forming chamber is configured to distribute the separated fibers onto the forming section of the forming line to form a cellulose preform structure. The grinding mill and forming chamber enable the cellulose preform structure to be formed tightly connected to the pressing module, eliminating the need for pre-manufacturing the cellulose preform structure, enabling a compact layout, and providing highly efficient operation of the product forming unit, wherein the cellulose raw material is used as the input material for the online production of the cellulose preform structure.

[0032] In some specific examples that can be combined with any or more of the above specific examples, the forming segment of the forming line extends along the upward forming direction of the preform. This makes it possible to design more compact and shorter product forming units, because the air-formed cellulose preform structure is initially routed upwards, and therefore not only in the horizontal direction.

[0033] In some specific examples that can be combined with any or more of the above specific examples, the preform dry forming module is configured to air-form discrete cellulose preforms onto a forming line, or the preform dry forming module is configured to air-form continuous cellulose preform structures onto a forming line. In some implementations, forming discrete cellulose preforms onto a forming line can result in a reduction in the level of residual material after forming, thereby reducing raw material costs.

[0034] In some specific instances that can be combined with any or more of the above specific instances, the pressing operation is a single pressing operation.

[0035] In some specific examples that can be combined with any or more of the above specific examples, the article forming unit is suitable for intermittently feeding cellulose preform structures from a preform dry forming module via a forming line along a first feed direction, and for intermittently feeding the cellulose preform structures to a pressing module along a second feed direction, wherein the second feed direction is different from the first feed direction; specifically, the second feed direction is opposite to or substantially opposite to the first feed direction. The different feed directions allow modules to be integrated into a single unit or machine that can be transported in a container within a few months, placed on the converter's factory floor, connected, and put into production with little or no need for the converter to acquire module engineering skills. Other advantages include a more compact layout and structure of the article forming unit achieved by the different feed directions. In this configuration, modules can be positioned relative to each other in unconventional ways to achieve an efficient and compact layout. Furthermore, the integrated module design allows the weight of the production forming unit to be several times less than that of units currently arranging discrete, separately purchased modules into custom industrial production lines. The weight of machinery is typically related to its purchase price, which is why this solution reduces the conversion cost for the user by several times. Lower investment costs allow for a faster conversion to products made from cellulose raw materials rather than plastics.

[0036] In some specific examples that can be combined with any or more of the above specific examples, the first feeding direction is upward and the second feeding direction is downward. This realizes a smart and efficient layout of the article forming unit, wherein the unit can be constructed along the vertical direction to achieve a compact layout.

[0037] In some specific examples that can be combined with any or more of the above-described specific examples, the product forming unit further includes a cellulose preform conveying device, specifically a conveyor belt and / or a set of feed rollers, configured to convey the air-formed cellulose preform structure from the forming line of the preform dry forming module to the forming die of the toggle pressing module, wherein an electronic control system is configured to provide substantially synchronized operation of the forming line and the conveying device. Thus, the need for an expensive cellulose preform buffer device is eliminated.

[0038] In some specific examples that can be combined with any or more of the above specific examples, the electronic control system is configured to continuously operate the mill; and to continuously feed cellulose raw materials to the mill, or to feed cellulose raw materials to the mill intermittently.

[0039] In some specific examples that can be combined with any or more of the above specific examples, the article forming unit further includes a preform recycling module configured to transport the remaining portion of the cellulose preform structure from the pressing module to the preform dry forming module. The transport of the remaining portion ensures that the unused portion of the cellulose preform structure can be reused.

[0040] In some specific examples that can be combined with any or more of the above specific examples, the billet recycling module includes a recycling compaction unit configured to compact residual portions of the cellulose billet structure within the recycling compaction unit during transport from the pressing module to the billet dry forming module. By compacting the residual portions, efficient operation of the mill can be achieved.

[0041] In some specific examples that can be combined with any or more of the above specific examples, the method includes controlling the operation of the forming line by means of an electronic control system to intermittently feed the forming line between subsequent pressing operations, such that the forming line operates periodically at a relatively high speed during the time period between subsequent pressing operations and at a relatively low speed or zero speed during the time period simultaneously with the pressing operation.

[0042] In some specific examples that can be combined with any or more of the above specific examples, the method includes controlling the operation of the forming line and the pressing actuator configuration to achieve synchronous operation of the forming line and the toggle press, such that the forming line operates or operates at a relatively high speed during the time period when the toggle press is in a non-pressing state, and such that the forming line is stationary or operates at a relatively low speed during the time period when the toggle press is in a pressing state.

[0043] In some specific examples that can be combined with any or more of the above specific examples, the method includes controlling the operation of the forming line and the toggle press by means of an electronic control system, such that the feed speed of the forming line is equal to or at least substantially equal to the feed speed of the air-formed cellulose preform structure entering the forming die.

[0044] In some specific instances that can be combined with any or more of the above specific examples, the method includes controlling the operation of adjusting the actuator configuration to adjust the distance between the first mold portion and the second mold portion during a time period between consecutive pressing actions, such that during the next pressing cycle, the target system of the pressing member provides a compressive force closer to a predetermined target pressing force.

[0045] In some specific examples that can be combined with any or more of the above specific examples, the step of air-forming a cellulose preform structure from cellulose raw material in a preform dry forming module involves: separating fibers from the cellulose raw material in a grinding mill, distributing the separated fibers onto the forming line of the preform dry forming module to form the cellulose preform structure, and conveying the formed cellulose preform structure along the upward preform forming direction. The unconventional upward extension of the forming section achieves a compact layout of the product forming units because the cellulose preform structure can be formed in the upward direction and then reoriented for conveying to the pressing module.

[0046] In some specific examples that can be combined with any or more of the above specific examples, the cellulose preform structure is air-formed into a discrete cellulose preform in a dry forming module, or the cellulose preform structure is air-formed into a continuous cellulose preform in a dry forming module.

[0047] In some specific examples that can be combined with any or more of the above specific examples, the cellulose preform structure is intermittently conveyed from the preform dry forming module by a forming line along a first feeding direction and intermittently fed to the pressing module along a second feeding direction, wherein the second feeding direction is different from the first feeding direction, specifically, wherein the second feeding direction is opposite to or substantially opposite to the first feeding direction.

[0048] In some specific examples that can be combined with any or more of the above specific examples, the method further includes the following steps: continuously operating the mill; and continuously feeding the cellulose raw material to the mill, or intermittently feeding the cellulose raw material to the mill. Thus, the composition of the resulting air-laid cellulose preform structure can be changed and adjusted according to specific circumstances.

[0049] In some specific examples that can be combined with any or more of the above specific examples, the forming line includes a forming section configured to connect with the forming chamber opening of the forming chamber, wherein the method further includes the step of: air-forming a cellulose preform structure onto the forming section. The forming section controls the forming of the cellulose preform structure onto the forming line, and the forming section can be used to shape the cellulose preform structure into a suitable configuration.

[0050] In some specific examples that can be combined with any or more of the above specific examples, the article forming unit includes a preform recycling module, wherein the method further includes the step of conveying the residual portion of the cellulose preform structure from the pressing module to the preform dry forming module.

[0051] In some specific examples that can be combined with any or more of the above specific examples, the billet recycling module includes a recycling compaction unit, wherein the method further includes the step of compacting the residual portion of the cellulose billet structure in the recycling compaction unit while it is being conveyed from the pressing module to the billet dry forming module.

[0052] This invention also relates to a toggle-joint pressing module for forming non-flat cellulose products from an air-formed cellulose preform structure. The toggle-joint pressing module comprises: a toggle press including a pressing member movably configured along the pressing direction; a toggle mechanism driven to the pressing member; a pressing actuator configuration driven to the toggle mechanism to control the movement of the toggle mechanism between a retracted operating position and an extended operating position; a forming die including a movable first die portion and a second die portion attached to the pressing member; an adjustment mechanism for adjusting the distance between the first die portion and the second die portion along the pressing direction while the toggle mechanism is in a non-moving operating state, and for adjusting the actuator configuration configured to drive... The device includes an adjustment mechanism, a pressure indication configuration, and an electronic control system operably connected to the pressure indication configuration, the pressure actuator configuration, and the adjustment actuator configuration. The electronic control system is configured to control the operation of the pressure actuator device to drive the pressing member in the pressing direction by setting the toggle mechanism to an extended operating position, thereby forming a non-flat cellulose article from an air-formed cellulose preform structure by pressing a first mold portion against a second mold portion. The electronic control system is also configured to control the operation of the adjustment actuator configuration based on pressure indication feedback information received from the pressure indication configuration.

[0053] The various states described above in the supplementary request can of course be combined with the elbow pressing module of this cellulose product.

[0054] This invention also relates to a method for molding a non-flat cellulose article from an air-formed cellulose preform structure in a toggle-type pressing module. The toggle-type pressing module comprises: a toggle press including a pressing member movably configured along the pressing direction; a toggle mechanism driven to the pressing member; and a pressing actuator configuration driven to the toggle mechanism to control the movement of the toggle mechanism between a retracted operating position and an extended operating position; a molding die including a movable first mold portion and a second mold portion attached to the pressing member; an adjustment mechanism for adjusting the distance between the first mold portion and the second mold portion along the pressing direction while the toggle mechanism is in a non-moving operating state, and for adjusting the actuator configuration configured to drive the adjustment mechanism; a pressing pressure indicator configuration; and an electronic control system operably connected to the pressing pressure indicator configuration, the pressing actuator configuration, and the adjusting actuator configuration. The method includes: air-forming a cellulose preform structure onto a forming line using a preform dry forming module; feeding the air-formed cellulose preform structure into a pressing area defined by spaced-apart first and second mold portions; controlling the operation of a pressing actuator assembly to perform a pressing operation, which involves driving a pressing member in the pressing direction by setting a toggle mechanism in an extended operating position, thereby pressing the first mold portion against the second mold portion to form a non-flat cellulose article from the air-formed cellulose preform structure; and controlling the operation of adjusting the actuator configuration based on pressing indication feedback information received from a pressing pressure indication configuration.

[0055] The various states described above from the subsidiary claims can, of course, be combined with this method for molding non-flat cellulose articles.

[0056] Other features and advantages of the invention will become apparent when the claims are examined and the following description is provided. Those skilled in the art will recognize that different features of the invention can be combined to form specific examples beyond those explicitly described above and below, without departing from the scope of the invention. Simple Explanation of the Diagram

[0057] Referring to the accompanying drawings, the article forming unit according to the present invention and the associated method for forming non-flat cellulose will be described in detail below. [Figure 1a] shows a schematic layout of the article forming unit according to the present invention. [Figure 1b] schematically shows a perspective view of the article forming unit according to the present invention. [Figure 1c] A perspective view schematically illustrating the blank dry forming module according to the present invention. Figures 1d to 1e schematically illustrate two specific examples of the route of the cellulose preform structure within the article forming unit according to the present invention. Figures 2a and 2b show two timing diagrams that reflect alternative control strategies for operating the article forming unit according to the invention. [Figure 3a] schematically shows a perspective view of the pressing module according to the present invention. Figures 3b to 3e schematically show side views of the cellulose molding process within a molding die according to the present invention. Figures 4a and 4b schematically show side views of the pressing module according to the present invention. [Figure 5] illustrates the main processing steps of the compression cycle. Figures 6a and 6b schematically show side views of an alternative orientation of the pressing module according to the present invention. [Figures 7a] to [Figures 7b] schematically show side views of an alternative design of the toggle mechanism according to the present invention. Figures 8a to 8c schematically show side views of alternative operation settings for the adjustment mechanism of the pressing module according to the present invention. [Figure 9] shows the pressure curve. [Figures 10a] to [Figures 10b] schematically illustrate an alternative control system for the pressing module according to the present invention. [Figure 11] shows an alternative schematic layout of the article forming unit according to the present invention. [Figures 12a] to [Figures 12b] schematically show side views of a pressing module according to yet another specific embodiment of the present invention, and [Figures 13] and [Figures 14] schematically illustrate some basic steps of various methods according to the present invention. Implementation

[0058] The following description, in conjunction with the accompanying drawings, illustrates various aspects of the invention in order to illustrate rather than limit the invention, wherein the same reference numerals denote the same elements, and variations of the described aspects are not limited to the specific examples shown, but are applicable to other variations of the invention.

[0059] Figures 1a and 1b schematically illustrate different examples of a product forming unit U for manufacturing cellulose articles 1 from an air-formed cellulose preform structure 2. Figure 1a shows a schematic layout of the product forming unit U, and Figure 1b shows a perspective side view of the product forming unit U. The product forming unit U has extensions in the horizontal direction or plane DH and the vertical direction DV. The product forming unit U includes a preform dry forming module 4 and a pressing module 6, as will be further described below.

[0060] Cellulose product 1 is formed from cellulose preform structure 2 in product forming unit U. Pressing module 6 includes one or more forming dies 3 for forming cellulose product 1 from cellulose preform structure 2 during pressing operation. Cellulose preform structure 2 is air-formed onto forming line 4c in preform dry forming module 4 and fed to one or more forming dies 3 of pressing module 6. The forming of cellulose product 1 is thus completed in pressing module 6. Cellulose product 1 is non-flat. Non-flat product refers to a product having extensions in three dimensions, unlike flat products such as preforms or sheets.

[0061] Air-formed cellulose preform structure 2 refers to a essentially air-formed fiber web structure made of cellulose fibers. Cellulose fibers can be derived from suitable cellulose raw materials R, such as pulp materials. Suitable pulp materials include, for example, fluff pulp, paper structures, or other structures containing cellulose fibers. Air-forming of the cellulose preform structure 2 refers to the formation of the cellulose preform structure during a dry forming process, wherein the cellulose fibers are air-formed to form the cellulose preform structure 2. When the cellulose preform structure 2 is air-formed during this process, the cellulose fibers are carried and formed into the fiber preform structure 2 by air as a carrier medium. This differs from ordinary papermaking processes or traditional wet forming processes, where water is used as a carrier medium for the cellulose fibers when forming paper or fiber structures.

[0062] During air forming, if desired, a small amount of water or other substances can be added to the cellulose fibers to alter the properties of the cellulose product, but air is still used as the carrier medium during the forming process. If appropriate, the cellulose preform structure 2 can have a dryness level primarily corresponding to the ambient humidity of the atmosphere surrounding the air-formed cellulose preform structure 2. Alternatively, the dryness of the cellulose preform structure 2 can be controlled to achieve a suitable dryness level when forming the cellulose product 1.

[0063] The preform dry forming module 4, illustrated in Figures 1a and 1b (shown separately in Figure 1c), has a horizontal distribution direction of cellulose fibers F from the grinder 4a to the forming line 4c via the forming chamber 4b. Therefore, a horizontal airflow feeds the cellulose fibers F from the grinder 4a to the forming section 4d, unlike conventional dry forming systems with vertical airflow. The fiber transport distance caused by the airflow inside the forming chamber 4b needs to be sufficiently long to minimize turbulence and / or generate a uniform flow of cellulose fibers F. Therefore, the length of the preform forming module 4 depends on the fiber transport distance caused by the airflow.

[0064] The upward billet forming direction DU enables a compact configuration and layout of the product forming unit U, and reduces the length of the product forming unit U compared to conventional solutions. Furthermore, since the billet dry forming unit 4 is positioned at the factory floor level, no additional raised floor structure or platform is required for maintenance of the grinding machine 4a from the factory floor level. This positioning and horizontal airflow also result in a lower height for the product forming unit U compared to conventional solutions using vertical airflow.

[0065] The cellulose preform structure 2 can be air-formed into discrete cellulose preforms in the dry forming module 4. The discrete cellulose preforms are formed into discrete blocks of material separated from each other and can be shaped, for example, into suitable configurations to avoid residual material after forming, thus minimizing the amount of cellulose material used. Alternatively, the cellulose preform structure 2 can be air-formed into a continuous cellulose preform 2b in the dry forming module 4. Depending on the air-forming process, the basis weight of the air-formed cellulose preform structure 2 can be uniform or variable.

[0066] Referring to Figures 1a and 1c, the preform dry forming module 4 includes a mill 4a, a forming chamber 4b, and a forming line 4c configured to connect to the forming chamber 4b. Fibers F from cellulose raw material R are separated from the cellulose raw material R in the mill 4a, and the separated fibers F are distributed from the forming chamber 4b to the forming line 4c to form the cellulose preform structure 2. The mill 4a is configured to separate the cellulose fibers F from the cellulose raw material R, and the forming chamber 4b is configured to distribute the separated fibers F onto the forming section 4d of the forming line 4c to form the cellulose preform structure 2. The forming section 4d is configured to connect to the forming chamber opening 4e of the forming chamber 4b. In the specific example described, the forming section 4d extends along the upward preform forming direction DU. The cellulose preform structure 2 is formed onto the forming section 4d and conveyed by the forming line 4c from the forming section 4d along the upward preform forming direction DU, and then further toward the pressing module 6. The upward blank forming direction DU is used for the compact configuration and layout of the product forming unit U, allowing different modules of the product forming unit U to be efficiently positioned relative to each other.

[0067] The pulp structure 20 used can be, for example, a bundle, sheet, or roll of fluff pulp, paper structure, or other suitable cellulose fiber-containing structure fed into the mill 4a. The mill 4a can be any known type, such as, for example, a hammer mill, a saw mill, or other type of pulp defiberizer. The pulp structure 20 is fed into the mill 4a through an inlet, and the separated fibers F are distributed to the forming chamber 4b through an outlet of the mill 4a configured to connect with the forming chamber 4b.

[0068] Forming chamber 4b is configured to distribute separated fibers onto forming line 4c for air-forming cellulose preform structure 2. Forming chamber 4b is configured as a cover structure or compartment connected to forming line 4c. Forming chamber 4b encloses the volume in which separated fibers F are distributed from mill 4a to forming line 4c. Cellulose fibers F are distributed by airflow generated by mill 4a, and the airflow transports the fibers in forming chamber 4b from mill 4a to forming line 4c.

[0069] The forming line 4c can be of any suitable known type and can be formed into an endless ring structure, as illustrated in Figures 1a and 1b. A vacuum chamber 4f can be configured to connect to the forming line 4c and the forming chamber 4b to control the airflow in the forming chamber 4b and distribute the separated fibers F onto the forming line 4c. The forming line 4c has a first side S1 facing the forming chamber 4b and a second side S2 facing the vacuum chamber 4f. When a negative pressure PNEG is applied to the second side S2 to fix the cellulose fibers F to the first side S1, the cellulose preform structure 2 is thus air-formed onto the first side S1 of the forming line 4c.

[0070] As illustrated in, for example, Figures 1a to 1c, the preform dry forming module 4 is positioned upstream of the pressing module 6. The pressing module 6 includes a toggle press 6a in which a forming die 3 is mounted. The toggle press 6a operates with a reciprocating motion having two main phases: an opening phase, during which the cellulose preform structure 2 is fed into the forming die, and a pressing phase, during which the cellulose preform structure 2 within the forming die is stationary. Therefore, the cellulose preform structure 2 needs to be intermittently fed to the forming die 3 of the pressing module 6.

[0071] According to the present invention, the intermittent feeding of the cellulose preform structure 2 to the molding die 3 of the pressing die 6 is achieved by the molding line 4c of the preform dry molding die 4, which is also intermittently operated in sync with the pressing die 6.

[0072] In the specific example of Figure 1a, the product forming unit U further includes an intermediate feeding device 16 disposed between the blank dry forming module 4 and the pressing module 6. The intermediate conveying or feeding device 16 may be a conveyor belt and / or a set of feed rollers or the like, and may also be configured to operate intermittently and synchronously with the pressing module 6. [ ]

[0073] In other words, the product forming unit U may further include a cellulose preform feeding device 16, specifically a conveyor belt, a set of feed rollers, a vacuum belt, an elongated traction belt feeder, or the like, configured to transport the air-formed cellulose preform structure 2 from the forming line 4c of the preform dry forming module 4 to the forming die 3 of the toggle pressing module 6, wherein the electronic control system 6h is configured to provide substantially synchronous operation of the forming line 4c and the conveying device. Thus, the forming line 4c and the conveying device always operate at substantially the same conveying speed.

[0074] Therefore, in the specific example of Figure 1a, the intermittent conveying of the cellulose preform structure 2 to the pressing die 6 is partially configured with a forming line 4c and partially with a suitable feeding device 16, which is intermittently controlled to feed the cellulose preform structure 2 to the pressing die 6. When the pressing die 6 operates to apply forming pressure PF to the cellulose preform structure 2, the cellulose preform structure 2 is in a non-moving state, or at least in a low operating speed state.

[0075] In other words, the cellulose preform structure 2 is fed to the molding position between one or more first mold portions 3a and one or more second mold portions 3b when the mold portions are in the open state, thereby allowing the cellulose preform structure 2 to be firmly positioned between one or more first mold portions 3a and one or more second mold portions 3b without any interfering interaction from the mold portions.

[0076] Therefore, this invention relates to a product forming unit U for manufacturing non-flat cellulose articles 1 from air-formed cellulose preform structures 2, wherein the product forming unit U includes a preform dry forming module 4 having a movable forming line 4c, an elbow pressing module 6 having an elbow press 6a and a forming die 3, and an electronic control system 6h operably connected to the forming line 4c and the elbow press 6a. The preform dry forming module 4 is configured to air-form the cellulose preform structure 2 onto the forming line 4c. Furthermore, the elbow press 6a includes a pressing member 6d movably arranged along the pressing direction DP, an elbow mechanism 6e driven to the pressing member 6d, and a pressing actuator arrangement 6f driven to the elbow mechanism 6e. Additionally, the forming die 3 includes a movable first die portion 3a and a second die portion 3b attached to the pressing member 6d. The electronic control system 6h is configured to control the operation of the pressing actuator configuration 6f to perform a pressing operation. This involves driving the pressing member 6d along the pressing direction DP by means of a toggle mechanism 6e, thereby forming a non-flat cellulose article from an air-formed cellulose preform structure by pressing the first mold portion 3a against the second mold portion 3b. Furthermore, the electronic control system 6h is further configured to intermittently feed the forming line 4c between subsequent pressing operations.

[0077] For example, the 4c ​​series of movable forming lines with breathable conveyor belts.

[0078] For example, the air-formed cellulose preform structure 2 is an air-formed fiber web structure made of cellulose fibers.

[0079] In the specific example of Figure 1a, the electronic control system 6h is operably connected to the drive motor 5 of the forming line 4c and the pressing actuator configuration 6f of the toggle press 6a.

[0080] After the pressing operation, the electronic control system 6h is configured to control the operation of the pressing actuator configuration 6f to drive the pressing member 6d in the opposite direction to the pressing direction DP to open the molding die 3.

[0081] Figure 2a describes a more detailed example of the first instance of the article forming unit U, which shows a timing diagram of a short operation sequence of the article forming unit U, including the operation speed VW (solid line) of the forming line 4c changing over time, and the operation speed VP (dashed line) of the pressing member changing over time.

[0082] During the first time period t1, the molding die 3 is in the open state, and the molding line 4c is temporarily started to feed a new segment of the cellulose preform structure 2 into the molding die 3. During the first time period t1, the operating speed VW of the molding line 4c changes from zero to a predetermined target speed V1, and then returns to zero. There is no buffer device or similar between the molding line 4c and the molding die 3, therefore, it can be assumed that the cellulose preform structure 2 has the same feed speed to the molding die as the operating speed VW of the molding line 4c.

[0083] During the second time period t2, in the specific example described, this second time period follows the first time period t1, except for a slight overlap with the end of the first time period t1. During this second time period t2, the pressing member 6d is controlled to move forward to close the molding die 3 and initiate the fiber forming event. During the second time period t2, the operating speed VP of the pressing member 6d changes from zero to a predetermined target speed and then returns to zero. The operating speed VW of the forming line 4c is zero at least during the end region of the second time period t2 to avoid supplying the cellulose preform structure 2 to the closed molding die 3.

[0084] During the third time period t3 following the second time period t2, both the forming line 4c and the pressing member 6d are controlled to temporarily maintain their operating positions, that is, remain in a non-moving state. During the third time period, the forming die 3 is closed and the toggle press 6a applies all the compressive force to the forming die. In other words, the third time period t3 corresponds to the fiber forming event of the cellulose preform structure 2 located in the forming die 3.

[0085] During the fourth time period t4 following the third time period t3, the pressing member 6d is controlled to move backward to open the molding die 3. During the fourth time period t4, the operating speed VP of the pressing member 6d changes from zero to a predetermined target speed, and then returns to zero speed. The return speed is described here as a negative value to indicate the direction of movement of the pressing member 6d, i.e., retraction.

[0086] At or after the end of the fourth time period t4, the operating speed VW of the forming line 4c changes from zero to the predetermined target speed again, thus repeating the periodic sequence t5. The total time period t5, consisting of the accumulated time periods t1 to t4, therefore represents the repetitive periodic operation sequence of the product forming unit U.

[0087] The timing diagram in Figure 2a clearly shows that the electronic control system 6h is configured to intermittently feed the forming line 4c. This is because the operating speed VW of the forming line 4c is obviously not constant, but changes periodically over the total time period t5.

[0088] Furthermore, the timing diagram in Figure 2a clearly shows that the electronic control system 6h is configured to feed the forming line 4c between subsequent pressing operations, i.e. before and after the third time period t3.

[0089] Figure 2a shows the electronic control system 6h configured to intermittently feed the forming line 4c between subsequent pressing operations, such that the forming line 4c operates periodically at a relatively high speed V1 during the time period t1 between subsequent pressing operations t3 and at zero speed during the time period t3 simultaneously with the pressing operation.

[0090] Figure 2b describes a second specific example of the operation of the article forming unit U in more detail. Figure 2b shows a timing diagram of a short operation sequence of the article forming unit U, including the operation speed VW (solid line) of the forming line 4c changing over time, and the operation speed VP (dashed line) of the pressing member changing over time.

[0091] In this specific example, the operating sequence and speed VP of the pressing member 6d are essentially equal to those described above with reference to Figure 2a. However, this specific example shows that the forming line 4c can be controlled to have a specific operating speed VW during the time period t3 concurrent with the pressing operation. This can be considered advantageous in some applications, for example, because it provides a smoother and smaller thickness variation in the resulting cellulose preform structure 2. On the other hand, such operational control of the forming line 4c typically requires a certain degree of buffering of the cellulose preform structure 2 during transport from the preform dry forming module 4 to the toggle pressing module 6.

[0092] During the time period t3 simultaneously with the pressing operation, the operating speed VW of the forming line 4c can be relatively low. In fact, the operating speed VW of the forming line 4c can even be partially zero and partially above zero during the time period t3 simultaneously with the pressing operation. Therefore, the buffering requirement can be kept relatively low and can be implemented, for example, by means of a variable-length suspension section or a variable-length bending section of the cellulose preform structure 2, or a relatively small-capacity buffer device of some type.

[0093] Referring to Figure 2b, during the first time period t1, the molding die 3 is in the open state, and the molding line 4c is controlled to feed new segments of the cellulose preform structure 2 into the molding die 3. During the first time period t1, the operating speed VW of the molding line 4c changes from a relatively low speed V2 to a predetermined relatively high speed V1, and then returns to a relatively low speed V2. For example, the relatively low speed V2 may be about 1-30% of the relatively high speed V1.

[0094] During the second time period t2, in the specific example described, this second time period follows the first time period t1, except for a slight overlap with the end of the first time period t1. During this second time period t2, the operating speed VP of the pressing member 6d changes from zero to a predetermined target speed and then returns to zero. In this specific example, the operating speed VW of the forming line 4c remains at a relatively low speed V1. Once the forming mold 3 is closed, the cellulose preform structure 2 begins to accumulate in the buffer.

[0095] During the third time period t3 following the second time period t2, both the forming line 4c and the pressing member 6d are controlled to temporarily maintain their operating positions, that is, remain in a non-moving state. This situation therefore corresponds to the fiber forming event of the cellulose preform structure 2 located in the forming mold 3.

[0096] During the fourth time period t4 following the third time period t3, the pressing member 6d is controlled to move backward to open the molding die 3. During the fourth time period t4, the operating speed VP of the pressing member 6d changes from zero to a predetermined target speed, and then returns to zero speed. The return speed is described here as a negative value to indicate the direction of movement of the pressing member 6d, i.e., retraction.

[0097] Once the molding die 3 is opened, the cellulose preform structure 2 in the buffer can be supplied to the molding die 3.

[0098] At the end of the fourth time period t4, the operation sequence restarts with time period t1.

[0099] The timing diagram in Figure 2b clearly shows that the electronic control system 6h can be configured to intermittently feed the forming line 4c. This is because the operating speed VW of the forming line 4c is obviously not constant, but changes periodically over the total time period t5.

[0100] Furthermore, the timing diagram in Figure 2b clearly shows that the electronic control system 6h is configured to feed the forming line 4c between subsequent pressing operations, i.e. before and after the third time period t3.

[0101] Additionally, Figure 2b shows that the electronic control system 6h can be configured to intermittently feed the forming line 4c between subsequent pressing operations, such that the forming line 4c operates periodically at a relatively high speed V1 during the time period t1 between subsequent pressing operations t3 and at a relatively low speed during the time period t3 simultaneously with the pressing operation.

[0102] In other words, the drive motor 5 of the forming line 4c operates according to a cycle sequence, which includes a relatively high speed in the first time period, followed by a relatively low speed or zero speed in the second time period.

[0103] Therefore, based on some specific examples, the electronic control system 6h is configured to synchronize the operation of the forming line 4c and the toggle press 6a, so that the forming line 4c operates or operates at a relatively high speed during the time period when the toggle press 6a is in a non-pressing state, and during the time period when the toggle press 6a is in a pressing state, the forming line 4c is in a stationary state or operates at a relatively low speed V2.

[0104] In other words, the electronic control system 6h can be configured to control the operation of the molding line 4c and the toggle press 6a, such that the feed speed of the molding line is, specifically, equal to or at least substantially equal to the feed speed of the air-formed cellulose preform structure 2 entering the molding die 3 within a complete pressing cycle t5.

[0105] Furthermore, the article forming unit U may be without the buffer module disposed between the blank dry forming module 4 and the toggle pressing module 6. This specifically refers to the article forming unit U described with reference to FIG2a.

[0106] Since the molding unit U may be without any buffer module or similar configuration, or at least with only a relatively small buffer capacity, the intermittent delivery of the cellulose preform structure to the pressing module needs to be synchronized with the air forming of the cellulose preform structure 2 in the preform dry forming module 4.

[0107] It should be understood that during the pressing operation, molding pressure may be applied to the cellulose preform structure 2 in only one pressing step, as described above with reference to Figures 2a and 2b. Alternatively, molding pressure may be applied in two or more repeated pressing steps during the pressing operation, and in this way, the mold portion repeatedly applies molding pressure to the cellulose preform structure.

[0108] Appropriately, the pressing operation is a single pressing operation, wherein molding pressure is applied to the cellulose preform structure 2 only in one pressing step during the pressing operation. Therefore, a single pressing operation means that the cellulose article 1 is formed from the cellulose preform structure 2 in a single pressing step within the pressing module 6. In a single pressing operation, one or more first mold portions 3a and one or more second mold portions 3b interact with each other during a single operation engagement step to establish molding pressure and molding temperature. In a single pressing operation, molding pressure and molding temperature are not applied to the cellulose preform structure 2 in two or more repeated or subsequent pressing operations.

[0109] As described above, the product forming unit U therefore includes an electronic control system 6h, which is configured to control the operation of both the blank dry forming module 4 and the toggle pressing module 6, and specifically to control the operation of one or more drive motors for driving the forming line 4c of the blank dry forming module 4, and to control the operation of the pressing actuator configuration 6f for driving the toggle pressing module 6.

[0110] Depending on the configuration of the air-formed cellulose preform structure 2 in the preform dry forming module 4, the mill 4a can operate in different ways. The mill 4a can be operated continuously. In one specific example, the cellulose raw material R is continuously fed to the mill 4a. In an alternative specific example, the cellulose raw material R is alternatively fed intermittently to the mill 4a.

[0111] The air-formed cellulose preform structure 2 can be formed from cellulose fibers in a conventional air-forming process or in a preform dry forming module 4 as illustrated in Figures 1a and 1b, and configured in different ways. For example, the cellulose preform structure 2 can have a composition in which the fibers have the same source or alternatively contain a mixture of two or more types of cellulose fibers, depending on the desired properties of the cellulose article 1. The cellulose fibers used in the cellulose preform structure 2 are firmly bonded to each other by means of hydrogen bonds during the forming process of the cellulose article 1. The cellulose fibers can be mixed with a certain amount of other substances or compounds, as will be further described below. Cellulose fibers refer to any type of cellulose fiber, such as natural cellulose fibers or man-made cellulose fibers. The cellulose preform structure 2 can specifically contain at least 95% cellulose fibers, or more specifically at least 99% cellulose fibers.

[0112] The air-formed cellulose preform structure 2 can have a single-layer or multi-layer configuration. A single-layer cellulose preform structure 2 refers to a structure formed from a single layer containing cellulose fibers. A multi-layer cellulose preform structure 2 refers to a structure formed from two or more layers containing cellulose fibers, wherein these layers may have the same or different compositions or configurations.

[0113] The cellulose preform structure 2 may include a reinforcing layer comprising cellulose fibers, wherein the reinforcing layer may be configured as a support layer for one or more other layers of the cellulose preform structure 2. The reinforcing layer may have a higher tensile strength than the other layers of the cellulose preform structure 2. This is useful when one or more air-formed layers of the cellulose preform structure 2 have a composition with low tensile strength, in order to prevent the cellulose preform structure 2 from breaking during the molding of the cellulose article 1. The reinforcing layer with higher tensile strength thus acts as a support structure for the other layers of the cellulose preform structure 2. The reinforcing layer may have a composition different from the rest of the cellulose preform structure, such as, for example, a tissue layer containing cellulose fibers, an air-formed network structure containing cellulose fibers, or other suitable layered structures. Therefore, the reinforcing layer need not be air-formed. If appropriate, the cellulose preform structure 2 may include more than one reinforcing layer.

[0114] The cellulose preform structure 2 may further include or be configured to be connected to one or more barrier layers, thereby giving the cellulose article the ability to retain or resist liquids, such as when the cellulose article 1 is used in contact with beverages, food and other aqueous substances. The one or more barrier layers may have a composition different from the rest of the cellulose preform structure 2, such as, for example, a tissue barrier structure.

[0115] The cellulose preform structure 2 is a loose and breathable structure of one or more air-forming layers, wherein the cellulose fibers of the forming structure are loosely arranged relative to each other. The loose cellulose preform structure 2 is used for efficient forming of the cellulose article 1, thereby allowing the cellulose fibers to be formed into the cellulose article 1 in an efficient manner during the forming process.

[0116] The article forming unit U may further include a barrier application module disposed upstream of the pressing module 6. The barrier application module is configured to apply barrier components to the cellulose preform structure 2 before forming the cellulose article 1 in one or more molding dies 3.

[0117] A preferred property of cellulose article 1 is its ability to contain or resist liquids, such as when the cellulose article is used in contact with beverages, food, and other aqueous substances. The barrier composition may be one or more additives used in the production of the cellulose article, such as AKD or latex, or other suitable barrier compositions. Another suitable barrier composition is a combination of AKD and latex, wherein testing has shown that unique article properties can be obtained by adding the combination of AKD and latex to the air-formed cellulose preform structure 2 when molding cellulose article 1. When using the combination of AKD and latex, a high degree of hydrophobicity is obtained, thereby giving cellulose article 1 a high ability to resist liquids (such as water) without negatively affecting the mechanical properties of cellulose article 1.

[0118] The barrier application module can be configured with a cover structure connected to the cellulose preform structure 2, and the cover structure includes nozzles for continuously or intermittently spraying the barrier composition onto the cellulose preform structure 2. In this manner, the barrier composition is applied to the cellulose preform structure 2 within the barrier application module. The barrier composition can be applied only to one side of the cellulose preform structure or alternatively to both sides. The barrier composition can be further applied over the entire surface or multiple surfaces of the cellulose preform structure 2, or only to a portion or area of ​​one or more surfaces of the cellulose preform structure 2. The cover structure of the barrier application module prevents the barrier composition from spreading into the surrounding environment. Other application techniques for applying the barrier structure may include, for example, slot coating and / or screen printing.

[0119] The product molding unit U is further adapted to form a non-flat cellulose product 1 from the cellulose preform structure 2 in one or more molding dies 3 by heating the cellulose preform structure 2 to a molding temperature TF and pressing the cellulose preform structure 2 with molding pressure. One or more molding dies 3 are configured to form the non-flat cellulose product 1 from the cellulose preform structure 2 by heating the cellulose preform structure 2 to a molding temperature TF in the range of 100-300°C and pressing the cellulose preform structure 2 with a molding pressure in the range of 1-100 MPa, preferably 4-20 MPa.

[0120] The different first feeding directions DF1 and second feeding directions DF2 allow for a compact configuration and layout of the product forming unit U, as well as efficient and compact positioning of the different modules of the product forming unit U relative to each other.

[0121] The product forming unit is suitable for intermittently feeding cellulose preform structures from a preform dry forming module via a forming line along a first feeding direction, and for intermittently feeding cellulose preform structures to a pressing module along a second feeding direction DF2, wherein the second feeding direction DF2 is different from the first feeding direction DF1. The different first feeding directions DF1 and second feeding directions DF2 allow for a compact configuration and layout of the product forming unit U, as well as efficient and compact positioning of the different modules of the product forming unit U relative to each other.

[0122] In some specific instances, the second feed direction DF2 is opposite to or substantially opposite to the first feed direction DF1.

[0123] The fact that the second feed direction DF2 is configured to be substantially opposite to the first feed direction DF1 means that the opposite directions of the second feed direction DF2 and the first feed direction DF1 are less than 45 degrees, specifically less than 30 degrees.

[0124] In the specific example described, the first feed direction DF1 is the upward direction, and the second feed direction DF2 is the downward direction, which allows for a compact and efficient configuration of the article forming unit U.

[0125] The specific examples of the cellulose preform structure 2 in Figures 1a and 1b are illustrated schematically in Figure 1d for clarity. The compact configuration and layout of the product molding unit U achieved by the cellulose preform structure 2, which first mainly upward, then mainly horizontal, and then mainly downward, can be clearly understood when compared with the conventional straight horizontal route in the compression molding process of cellulose products.

[0126] Alternatively, the preform dry forming module 4 can be configured with a predominantly horizontal orientation for the feed path and feed direction of the cellulose preform structure 2, that is, a predominantly horizontal orientation for the forming line 4c in the area of ​​the forming chamber opening 4e, as schematically illustrated in FIG1e, before routing the cellulose preform structure 2 upwards, then predominantly horizontally, and subsequently predominantly downwards to the pressing module 6. This layout of the article forming unit U can also be used to provide a compact article forming unit U.

[0127] Referring to Figures 1d to 1e, when the billet recycling module 7 is not considered, the billet dry forming module 4 typically forms the starting point of the feed path, and the pressing module 6 typically forms the ending point of the feed path. Other modules (such as the barrier application module) are located at any suitable location between the dry forming module 4 and the pressing module 6, that is, downstream of the dry forming module 4 and upstream of the pressing module 6, and not necessarily at the specific locations shown in the examples of Figures 1a to 1b.

[0128] The downward route of the cellulose preform structure as it passes through the pressing mold 6 is advantageous in the following ways: it simplifies the feeding of the cellulose preform structure 2 and simplifies the plundering of the cellulose product 1 after the molding process is completed (i.e., when it leaves the pressing mold 6).

[0129] Specifically, the high-speed intermittent feeding of the cellulose preform structure 2 from the dry forming module 4 to the pressing module 6 may be difficult to complete, potentially damaging or altering the properties of the cellulose preform structure 2, such as its thickness or similar characteristics. However, by configuring the toggle press along the main horizontal direction DH and feeding the cellulose preform structure primarily downwards to the pressing module 6, gravity assists this feeding process, thus requiring a smaller force applied by the feeding device 16 to feed the air-formed cellulose preform structure 2 to the pressing area 15 of the pressing module 6, thereby reducing the risk of damage and / or alteration of the properties of the cellulose preform structure 2.

[0130] Furthermore, the collection of the finished product and discharged cellulose product 1 after the complete molding process can be simplified by using the molding mold 3 with the main vertical route of the cellulose preform structure 2. This is because gravity can also assist and simplify the removal of the finished product and discharged cellulose product 1 from the molding mold 3 and then transport them to the storage room or conveyor belt or the like.

[0131] The pressing module 6 includes one or more molding dies 3, as indicated in Figures 1a to 1b and Figure 3a, and each molding die 3 includes a first die portion 3a and a second die portion 3b. During the molding of the non-flat cellulose article 1 in the pressing module 6, the corresponding first and second die portions cooperate with each other. Each first die portion 3a and the corresponding second die portion 3b are movably configured relative to each other, and the first die portion 3a and the second die portion 3b are configured to move relative to each other along the pressing direction DP.

[0132] In the specific examples illustrated in Figures 1a to 1b and Figures 3a to 3e, the second mold portion 3b is stationary, and the first mold portion 3a is movably configured relative to the second mold portion 3b along the pressing direction DP, and then returns to its original position. As indicated by the double arrows in Figure 3b, the first mold portion 3a is configured to move linearly along an axis extending along the pressing direction DP, both toward and away from the second mold portion 3b.

[0133] In alternative specific examples, the first mold portion 3a may be stationary, while the second mold portion 3b may be movably configured relative to the first mold portion 3a, or both the first mold portion 3a and the second mold portion 3b may be movably configured relative to each other.

[0134] The pressing module 6 can be a single-cavity configuration or alternatively a multi-cavity configuration. A single-cavity pressing module comprises only one molding die 3 having first and second mold portions. A multi-cavity pressing module comprises two or more molding dies 3, each having cooperating first and second mold portions. In the specific examples illustrated in Figures 1a-1b and 3a, the pressing module 6 is configured as a multi-cavity pressing module comprising a plurality of molding dies 3 having first and second mold portions, wherein the movement of the mold portions is suitably synchronized for simultaneous molding operations. A portion of the pressing module 6 shown in Figures 3b-3e illustrates a single-cavity configuration, or alternatively, a segment of a multi-cavity configuration with one molding die 3. The pressing module 6 will be described below in conjunction with a multi-cavity pressing module, but the invention is equally applicable to single-cavity pressing modules.

[0135] It should be understood that, for all specific embodiments of the invention, the description of movement along the pressing direction DP includes movement of DP along the pressing direction, and this movement can occur in the opposite direction. The description may further include both linear and nonlinear movement of the mold portion, wherein the result of the movement during molding is the repositioning of the mold portion along the pressing direction DP.

[0136] To form a non-flat cellulose article 1 from an air-formed cellulose preform structure 2 in the article forming unit U, the cellulose preform structure 2 is first provided from a suitable source. The cellulose preform structure 2 can be air-formed from cellulose fibers and disposed on rollers or in a stack. Subsequently, the rollers or stacks can be configured to connect to the molding die system S. Alternatively, the cellulose preform structure 2 can be air-formed from cellulose fibers in the preform dry forming module 4 of the article forming unit U and fed directly to the pressing module 6.

[0137] Cellulose articles 1 are formed from cellulose preform structures 2 by heating them to a molding temperature TF in the range of 100-300°C and pressing them with a molding pressure in the range of 1-100 MPa (preferably 4-20 MPa) in one or more molding dies 3. A first die portion 3a is configured to form non-flat cellulose articles 1 by interaction with a corresponding second die portion 3b, as illustrated in Figures 3b to 3e. During the molding of the cellulose article 1, the cellulose preform structure 2 is subjected to a molding pressure in the range of 1-100 MPa (preferably in the range of 4-20 MPa) and a molding temperature TF in the range of 100-300°C in each molding die 3. Therefore, by heating the cellulose preform structure 2 to a molding temperature TF in the range of 100-300°C, and by pressing the cellulose preform structure 2 with a molding pressure in the range of 1-100 MPa (preferably in the range of 4-20 MPa), a cellulose article 1 is formed from the cellulose preform structure 2 between each of the first mold portion 3a and the corresponding second mold portion 3b. When the cellulose article 1 is molded, strong hydrogen bonds are formed between the cellulose fibers disposed in the cellulose preform structure 2 between the first mold portion 3a and the second mold portion 3b. For example, during the molding process, temperature and pressure levels are measured in the cellulose preform structure 2 using suitable sensors disposed in or connected to the cellulose fibers in the cellulose preform structure 2.

[0138] The pressing module 6 may further include a heating unit. The heating unit is configured to apply a molding temperature TF to the cellulose preform structure 2 in each molding die 3. The heating unit can have any suitable configuration. The heating unit can be integrated or cast into the first die portion 3a and / or the second die portion 3b, and suitable heating devices are, for example, electric heaters, such as resistive elements, or fluid heaters. Other suitable heat sources may also be used.

[0139] When the cellulose preform structure 2 is positioned in the molding position between the first mold portion 3a and the second mold portion 3b, as shown in Figure 3b, the first mold portion 3a moves toward the second mold portion 3b along the pressing direction DP, as illustrated by the arrow in Figure 3c. As the first mold portion 3a moves toward the second mold portion 3b, the cellulose preform structure 2 is increasingly compacted between the pressing surfaces 3c and 3d of the mold portions until the first mold portion 3a has moved further toward the second mold portion 3b and reached the product molding position, as shown in Figure 3d, where molding pressure and molding temperature TF are applied to the cellulose preform structure 2. When each first mold portion 3a is pressed toward its corresponding second mold portion 3b by means of the cellulose preform structure 2 positioned between the mold portions, a molding cavity C for molding the cellulose product 1 is formed between each first mold portion 3a and the second mold portion 3b during the molding of the cellulose product 1. Molding pressure and molding temperature TF are applied to the cellulose preform structure 2 in each molding cavity C.

[0140] The molding of the cellulose article 1 may further include edge forming operations and cutting or separating operations in the pressing mold assembly 6, wherein an edge is formed on the cellulose article 1 and wherein the cellulose article 1 is separated from the cellulose preform structure 2 during molding. For example, the mold portion may be configured with edge forming and cutting or separating devices for such operations, or alternatively, the edge may be formed in the article cutting or separating operation. Once the cellulose article 1 has been molded in the molding mold system S, the first mold portion 3a moves away from the second mold portion 3b, as shown in FIG. 3e, and the cellulose article 1 can be removed from the pressing mold assembly 6, for example by using a release rod or similar device.

[0141] The deformation element E used to establish the molding pressure can be configured to connect to each of the first mold portion 3a and / or the second mold portion 3b. In the specific examples illustrated in Figures 3b to 3e, the deformation element E is attached to the first mold portion 3a. By using the deformation element E, the molding pressure can be configured as an equal-pressure molding pressure.

[0142] The first mold portion 3a and / or the second mold portion 3b may include a deformable element E, configured to apply molding pressure to the cellulose preform structure 2 in the molding cavity C during the molding of the cellulose article 1. The deformable element E may be attached to the first mold portion 3a and / or the second mold portion 3b using suitable attachment devices (such as, for example, adhesive or mechanical fasteners). During the molding of the cellulose article 1, the deformable element E deforms to apply molding pressure to the cellulose preform structure 2 in the molding cavity C, and through the deformation of the deformable element E, a balanced pressure distribution is achieved even if the cellulose article 1 has a complex three-dimensional shape, or if the cellulose preform structure 2 has varying thickness. To apply the required molding pressure to the cellulose preform structure 2, the deformable element E is made of a material that can deform when force or pressure is applied, and the deformable element E is appropriately made of an elastic material that can recover its size and shape after deformation. The deformable element E may further be made of a material with suitable properties capable of withstanding the high molding pressure and molding temperature TF level used in molding the cellulose article 1.

[0143] Certain elastic or deformable materials exhibit fluid-like properties when exposed to high pressure levels. If the deformable element E is made of such a material, a uniform pressure distribution can be achieved during molding, wherein the pressure exerted by the deformable element E on the cellulose preform structure 2 in the molding cavity C is equal or substantially equal in all directions between the mold portions. A uniform fluid-like pressure distribution is achieved when each pressurized deformable element E is in its fluid state. Molding pressure is thus applied to the cellulose preform structure 2 from all directions by means of such a material, and the deformable element E thereby applies uniform molding pressure to the cellulose preform structure 2 during the molding of the cellulose article 1. Each deformable element E can be made of a suitable structure of one or more elastic materials, and as an example, the deformable element E can be made of a block or substantially block structure of a gel material, silicone rubber, polyurethane, polychloroprene, or rubber with a hardness in the range of 20-90 Shore A.

[0144] Furthermore, in the specific examples illustrated in Figures 1a and 1b, the article forming unit U includes a preform recovery module 7 for recovering cellulose fibers. The preform recovery module 7 is configured to feed the residual portion 2c of the cellulose preform structure 2 back from the pressing module 6 to the preform dry forming module 4 after forming the cellulose article 1. The preform recovery module 7 is configured to convey the residual cellulose preform fiber material from the pressing module 6 to the milling machine 4a. After forming the cellulose article 1 in the forming mold 3, a residual portion 2c of the cellulose preform structure containing cellulose preform fiber material may remain. Using the preform recovery module 7, the residual or remaining cellulose fibers can be recovered and reused together with fibers from the cellulose raw material to form a new cellulose preform structure 2. Specific examples of the preform recovery module 7 are schematically illustrated in Figures 1a and 1b. The preform recovery module 7 includes a feeding structure 7a, such as a feed belt, conveyor structure, or other suitable means for conveying the residual portion 2c from the forming mold 3 to the milling machine 4a. The mill 4a may be configured with a separate inlet opening for residual material, wherein the residual portion 2c of the cellulose preform structure 2 is fed into the mill 4a.

[0145] The preform recycling module 7 may include a recycling compaction unit 7b. The recycling compaction unit 7b compacts the residual portion 2c of the cellulose preform structure 2 as it is conveyed from the pressing module 6 to the preform dry forming module 4. Suitablely, the recycling compaction unit 7b is configured as a pair of cooperating rollers that compact the residual portion 2c of the cellulose preform structure 2, as shown in FIG. 1a.

[0146] In an example not specified, the preform recovery module 7 may alternatively include a channel structure with an inlet portion configured to connect to the molding die 3, through which residual portions 2c of the cellulose preform structure can be drawn into the inlet portion for further conveying to the grinder 4a. The channel structure may further be configured with a suitable combined grinder and fan unit for at least partially separating residual material before further conveying to an outlet portion connected to the grinder 4a.

[0147] The billet recovery module 7 may further include a buffer configuration 51, the purpose of which is to convert the intermittent feeding motion of the residual portion 2c leaving the pressing module 6a into a continuous feeding motion before supplying the residual portion 2c to the mill 4a. This is particularly relevant when the residual portion 2c has a continuous web structure. Continuously feeding the residual portion 2c to the mill 4a is advantageous in terms of a more equal supply rate of the residual portion 2c, and thus forms a more uniformly thick cellulose billet structure 2 in the forming line 4c. However, due to the intermittent operation of the pressing module 6a, the intermittent supply of the residual portion 2c from the pressing module 6a needs to be converted into continuous feeding without damaging the web structure of the residual portion 2c. To achieve this, the buffer configuration 51 may include a residual portion 2c feeding system configured to intermittently feed the residual portion 2c to the buffer configuration 51 and continuously feed the residual portion 2c from the buffer module 5.

[0148] The buffer configuration 51 can be implemented in the form of a suspended section forming a continuous structure of the residual portion 2c. In the suspended section, the residual portion 2c lacks vertical support from the conveyor belt or the like and is therefore freely suspended, wherein the buffering effect is achieved by allowing the residual portion 2c to be suspended deep or shallowly in the suspended section. Alternatively, the buffer configuration 51 can be implemented in the form of a mechanical device having one or more moving parts controlled by actuators.

[0149] The aforementioned modules enable a compact structure for the product forming unit U, which can be integrated into a single product forming unit U. This single product forming unit can be easily transported in a container and placed on the factory floor of the converter. Different feed directions further enhance the compact layout and structure of the product forming unit U.

[0150] The following describes some specific examples of the pressing module 6 in more detail with reference to the schematic diagrams in Figures 3a and 4a to 4b, wherein Figure 4a shows the toggle press 6a in the open state, and Figure 4b shows the same toggle press 6a during the pressing action.

[0151] The elbow pressing module 6 for cellulose products is specifically suitable for molding non-flat cellulose products 1 from air-formed continuous cellulose preform structures 2. This is because the continuous cellulose preform structure 2 simplifies the handling of the preform structure 2 and its feeding to the elbow press 6a, and simplifies the feeding of the remaining portion 2c of the cellulose preform structure 2 to the preform recycling module 7. However, the elbow pressing module 6 for cellulose products is also suitable for molding non-flat cellulose products 1 from air-formed discontinuous cellulose preform structures 2 (such as individual sheets of air-formed cellulose preform structures 2).

[0152] For example, the push-actuator configuration 6f may include one or more hydraulic or pneumatic linear actuators, such as cylinder-piston actuators. Alternatively, a motor with a rotary output shaft, such as an electric, hydraulic, or pneumatic motor, may be used to drive mechanical actuators, specifically linear mechanical actuators, such as ball screws, screw actuators, rack and pinion actuators, etc. More alternatively, the push-actuator configuration 6f may include a high-torque electric motor driven to the toggle mechanism 6e via a rotary-linear transmission such as an eccentric mechanism or crankshaft configuration. Even further alternatively, the push-actuator configuration 6f may include one or more high-torque electric motors integrally mounted in the toggle mechanism 6e and directly driven to the rotating members or pivoting links of the toggle mechanism 6e.

[0153] The movable first mold portion 3a can be attached directly or indirectly to the pressing member 6d. This means, for example, that an intermediate member, such as a force gauge or the like, can be disposed between the movable first mold portion 3a and the pressing member 6d for detecting the pressing force.

[0154] The stationary second mold section 3b is typically stationary during the pressing action, but can still be adjusted along the pressing direction DP during the time interval between consecutive pressing actions, as will be described in more detail below.

[0155] In some specific examples, the toggle press 6a includes a front structure 6b and a rear structure 6c, wherein the toggle mechanism 6e is also connected to the rear structure 6c, and wherein the stationary second mold portion 3b is attached to the front structure 6b.

[0156] The stationary second mold portion 3b may be directly or indirectly attached to the front structure 6b. This means, for example, that an intermediate component may be disposed between the stationary second mold portion 3b and the front structure 6b, such as a force gauge for detecting pressing pressure, or the like.

[0157] The front structure 6b and rear structure 6c of the toggle press 6a represent two rigid and structurally related parts that must be interconnected by some structurally rigid construction to ensure that the front structure 6b and rear structure 6c do not separate during the pressing process. Depending on the specific circumstances, the front structure 6b and rear structure 6c can have many different forms. For example, the front structure 6b and rear structure 6c can have a plate-like shape, specifically a rectangular plate-like shape, thereby enabling cost-effective manufacturing and the possibility of using the corner areas of the plate-like front structure 6b and rear structure 6c for attachment to a common rigid frame structure.

[0158] In fact, the toggle press 6a typically comprises a rigid frame structure defined by a front structure 6b, a rear structure 6c, and an intermediate frame structure connecting the front structure 6b and the rear structure 6c.

[0159] In some specific examples, the toggle press 6a includes a rigid frame structure defined by a front structure 6b, a rear structure 6c, and an intermediate linear guide configuration 14 connecting the front structure 6b and the rear structure 6c, wherein the pressing member 6d is movably attached to the linear guide configuration 14 and is movable along the pressing direction DP. The rigid frame structure can be positioned on an underlying support frame 38 to provide the desired height and angle tilt of the toggle pressing module 6.

[0160] In other words, the intermediate frame structure can be provided by an intermediate linear guide configuration 14, which has a dual function in providing structural strength and stiffness to the toggle press 6a, providing a rigid connection between the front structure 6b and the rear structure 6c, and additionally providing an intermediate linear guide configuration 14 for guiding the pressing member 6d.

[0161] To achieve a cost-effective and robust frame structure for the toggle press 6a, the intermediate linear guide configuration 14 may include four tie rods 37, one of which is located in each corner region of the plate-shaped front structure 6b and rear structure 6c. For example, the tie rods are cylindrical, and corresponding cylindrical holes may be provided in the corner regions of the plate-shaped front structure 6b and rear structure 6c to receive the tie rods.

[0162] The pressing member 6d can have any structural shape. However, in some specific examples, the pressing member also has at least a plate-like shape, specifically a rectangular plate-like shape, thereby enabling cost-effective manufacturing and the possibility of using the corner areas of the plate-like pressing member 6d to attach to the intermediate linear guide configuration 14. Therefore, the toggle press 6a can be referred to as a three-plate press in some specific examples.

[0163] The toggle press 6a is installed or configured to be installed such that the pressing direction of the pressing member 6d is primarily arranged or oriented along the horizontal direction DH. In this context, "primarily arranged along the horizontal direction DH" means that the pressing direction is configured to be closer to the horizontal direction than the vertical direction, i.e., less than 45 degrees. Specifically, the toggle press 6a may be installed or configured such that the pressing direction of the pressing member 6d is configured within 20 degrees of the horizontal direction, and more specifically, the pressing direction is parallel to the horizontal direction.

[0164] As illustrated in Figures 1a-1b, 3a, and 4a-4b, the toggle press 6a is, for example, mounted such that the pressing direction DP of the pressing member 6d is arranged in the horizontal direction. However, referring to Figures 6a-6b, when the toggle press 6a is mounted in a slightly tilted state, a favorable configuration for achieving a compact overall design and low build height of the cellulose product molding unit U can also be obtained, depending on the situation. Therefore, the favorable configuration of the toggle pressing module 6 for cellulose products can be considered to be obtained by means of the toggle press 6a, which is configured such that the pressing direction DP of the pressing member 6d is mainly arranged in the horizontal direction DH, that is, the pressing direction DP of the pressing member 6d is arranged in the horizontal direction DH more than the vertical direction DV. In other words, the toggle press 6a can be installed such that the pressing direction DP of the pressing member 6d is configured with an installation angle 13 in the range of 0-44 degrees (specifically in the range of 0-20 degrees), wherein the installation angle is defined by the pressing direction DP and the horizontal direction DH.

[0165] Furthermore, as illustrated in Figures 6a and 6b, not only when the rear structure 6c of the toggle press 6a is positioned higher than the front structure 6b of the toggle press (as illustrated in Figure 6a), but also when the front structure 6b of the toggle press 6a is positioned higher than the rear structure 6c of the toggle press (as illustrated in Figure 6b), an advantageous configuration of a compact overall design and low build height for the cellulose product molding unit U can be achieved. By way of example only, in Figure 6a, the power supply 39 for the press actuator configuration 6f is shown to be mounted below the support frame 38, and in Figure 6b, for example, the product receiving configuration 48 is shown to be mounted below the support frame 38.

[0166] In some specific examples, the toggle press 6a further includes a feeding device 16 for intermittently feeding the air-formed cellulose preform structure 2 into a pressing region 15 located between the first mold portion 3a and the second mold portion 3b. The feeding device 16 is configured to feed the air-formed cellulose preform structure 2 primarily vertically downward into the pressing region 15, specifically to feed the air-formed cellulose preform structure 2 downward into the pressing region 15 at a feeding angle 49 of less than 20 degrees with respect to the vertical direction, and more specifically, to feed the air-formed cellulose preform structure vertically downward into the pressing region 15.

[0167] As mentioned above, the term "primarily vertical" here means a feeding structure configured to be more vertical than horizontal. In other words, the straight portion of the feeding device 16 is oriented to define an angle 49 with respect to the vertical direction within the range of 0-44 degrees (specifically 0-20 degrees). Therefore, the feeding device 16 can be considered to be primarily located on the forming die 3.

[0168] Furthermore, the downward arrangement of the pressing module 6 causes the pressing direction DP to be primarily oriented along the horizontal direction DH. This also results in the plane defined by the internal (typically substantially flat) side surfaces of the first mold portion 3a and the second mold portion 3b being primarily positioned in the vertical direction DV, i.e., defining an angle within the range of 0-44 degrees (specifically 0-20 degrees) with respect to the vertical direction DV. The internal flat side surfaces of the first mold portion 3a and the second mold portion 3b refer to the surfaces of the first mold portion 3a and the second mold portion 3b that face each other and surround the pressing surface of the pressing cavity.

[0169] According to some specific examples, the feeding device 16 for feeding the air-formed cellulose preform structure 2 into the pressing area 15 may include an electrically driven feed roller or a pair of electrically driven feed rollers, or an elongated vacuum belt feeder or an elongated traction belt feeder or the like, wherein the intended feeding direction is configured primarily along the vertical direction DV, specifically configured such that the elongation direction 17 is within 20 degrees of the vertical direction DV, and more specifically configured to be parallel to the vertical direction DV.

[0170] The toggle mechanism 6e of the toggle press 6a can have various designs and implementations. The basic requirement of the toggle mechanism 6e is to generate pressing force amplification, thereby enabling the use of a pressing actuator configuration 6f, which is relatively low-cost and has a smaller capacity in terms of pressing force. Pressing force amplification is achieved by correspondingly reducing the pressing speed of the pressing module. Therefore, compared to the force / speed of the pressing actuator configuration 6f, the toggle mechanism 6e amplifies and slows down the pressing force / speed.

[0171] Generally speaking, and referring to the specific examples in Figures 1a to 1b, 3a and 4a to 4b, the toggle mechanism 6e includes a first link member 18 and a second link member 19, wherein a press actuator configuration 6f is directly or indirectly connected to the first link member 18 or the second link member 19 in a driven manner, such that actuation of the press actuator configuration 6f causes movement of the press member 6d.

[0172] More specifically, in some specific examples, the toggle mechanism 6e may include a first link member 18 and a second link member 19, each link member having first and second pivot connections 18a, 18b, 19a, 19b, wherein the first pivot connection 18a of the first link member 18 is pivotally connected to the rear structure 6c, wherein the first pivot connection 19a of the second link member 19 is pivotally connected to the pressing member 6d, wherein the second pivot connection 18b of the first link member 18 is pivotally connected to the second pivot connection 19b of the second link member 19, and wherein a pressing actuator configuration 6f is directly or indirectly driven to the first link member 18 or the second link member 19 for adjusting the alignment between the first link member 18 and the second link member 19, such that actuation of the pressing actuator configuration 6f causes movement of the pressing member 6d.

[0173] The fact that the second pivot connector 18b of the first link member 18 is pivotally connected to the second pivot connector 19b of the second link member 19 means that the second pivot connector 18b of the first link member 18 is the same as the second pivot connector 19b of the second link member 19.

[0174] Figures 4a and 4b illustrate the effect of adjusting the alignment between the first link member 18 and the second link member 19. The alignment between the first link member 18 and the second link member 19 is determined by the alignment angle 22 defined by the longitudinal directions of the first link member 18 and the second link member 19, as seen in the side views of Figures 4a and 4b. The longitudinal direction 18d of the first link member 18 is defined by a straight line passing through the first pivot connector 18a and the second pivot connector 18b of the first link member, and the longitudinal direction 19d of the second link member 19 is defined by a straight line passing through the first pivot connector 19a and the second pivot connector 19b of the second link member 19.

[0175] In Figure 4b, the alignment angle 22 is 180 degrees, which corresponds to the alignment of the first link member 18 and the second link member 19. This actuation position of the toggle mechanism 6e can be called the force-balanced position. The force-balanced position is the position where all forces are in equilibrium and their effects cancel each other out. In other words, in the force-balanced position, the force required to press the actuator configuration 6f is equal to zero.

[0176] In some specific instances, depending on the specific design of the toggle mechanism 6e, such pressing operations involve controlling the pressing actuator configuration 6f to set the toggle mechanism 6e in the force-balanced position.

[0177] In some specific examples of toggle mechanism design, such as those shown in Figures 4a and 4b, the force balance position corresponds to the maximum extension operation position of toggle mechanism 6e.

[0178] The toggle mechanism 6e illustrated in the examples of Figures 4a and 4b can be referred to as a five-point double toggle mechanism, meaning that there are two separate toggle mechanisms that are arranged side by side to provide a better force distribution to the pressing member 6d, and each of the two separate toggle mechanisms includes five pivot points.

[0179] Specifically, in the examples of Figures 4a to 4b, the press actuator configuration 6f is driven to a single crosshead 20, and the crosshead linkage member 21 has a first connector 21a pivotally connected to the crosshead 20 and a second connector 21b pivotally connected to a third pivot connector 18c of the first linkage member 18.

[0180] In other words, the toggle mechanism 6e of the specific examples in Figures 4a to 4b includes a single crosshead driving a first and a second separate toggle mechanism arranged side by side. Each toggle mechanism includes a first link member 18, a second link member 19, and a crosshead link member 21. The first link member 18 is pivotally connected to the second link member 19 and the rear structure 6c. The second link member 19 is pivotally connected to the pressing member 6d. The crosshead link member 21 is pivotally connected to the first link member 18 and the crosshead 20.

[0181] Within the scope of this invention, many alternative designs for the toggle mechanism 6e are possible. For example, the crosshead link member 21 can be pivotally connected to the second link member 19 and the crosshead 20. Furthermore, the second pivot connector 18b and the third pivot connector 18c of the first link member 18 can be alternatively common pivot connectors.

[0182] Furthermore, the toggle mechanism 6e can be a three-point single toggle mechanism as illustrated in FIG6a, wherein the toggle mechanism 6e includes a first link member 18 pivotally connected to the second link member 19, wherein the first link member 18 is also pivotally connected to the rear structure 6c and the second link member 19 is pivotally connected to the front structure 6b, and the press actuator configuration 6f is directly or indirectly connected to the first link member 18 or the second link member 19 in a driving manner, such that actuating the press actuator configuration 6f causes the movement of the press member 6d.

[0183] Figure 7a schematically illustrates another example design of the toggle mechanism 6e, showing a three-point double toggle mechanism, i.e., two three-point single toggle mechanisms as described with reference to Figure 6a, wherein a press or pull actuator configuration 6f is directly or indirectly driven to the first link member 18 and / or the second link member 19 of the two single toggle mechanisms. Furthermore, in this specific example, an electric servo motor is depicted as the actuator configuration 6f.

[0184] According to another specific example, the toggle mechanism 6e schematically illustrated in FIG7b includes a three-point double toggle mechanism, that is, two three-point single toggle mechanisms as described with reference to FIG6a, but here the first link member 18 and / or the second link member 19 of the two single toggle mechanisms operate in opposite directions and have an actuator configuration 6f disposed therebetween, and are directly or indirectly driven to the first link member and / or the second link member.

[0185] Referring again to Figures 3a and 4a to 4b, in some specific examples, the toggle press 6a further includes: a pressure indication configuration 6g; an adjustment mechanism 23 for adjusting the distance between the first mold portion 3a and the second mold portion 3b in the pressing direction while keeping the toggle mechanism 6e in a non-moving operating state; and an adjustment actuator configuration 25 configured to drive the adjustment mechanism 23, wherein an electronic control system 6h is operably connected to the pressure indication configuration 6g and configured to control the operation of the adjustment actuator configuration 25 based on pressure indication feedback information received from the pressure indication configuration 6g.

[0186] For example, the mechanical adjustment mechanism 23 may include four gears 26a to 26d, each gear having an internal thread for threaded mounting on a corresponding threaded end of a pull rod of the linear guide configuration 14, and each gear 26a to 26d having external gear teeth for being driven by one or more motors of the adjustment actuator configuration 25.

[0187] For example, as illustrated in Figures 3a and 4a to 4b, each of the four gears 26a to 26d of the mechanical adjustment mechanism 23 can engage with and be driven by a single central gear 27, which is powered by a single motor of the adjustment actuator configuration 25.

[0188] The operation of adjusting the actuator configuration 25 causes the mechanical adjustment mechanism 23 to change the distance 24 between the front structure 6b and the rear structure 6c in the pressing direction, so that the distance between the first mold part 3a and the second mold part 3b can be adjusted while the toggle mechanism 6e is in a non-moving operating state. This means that the adjustment of this distance is not caused by the movement of the toggle mechanism, but by the change in the distance between the front structure 6b and the rear structure 6c.

[0189] In the specific examples of Figures 3a and 4a to 4b, the operation of the mechanical adjustment mechanism 23 causes the rear structure 6c to shift relative to the linear guide configuration 14, thereby changing the distance 24 between the front structure 6b and the rear structure 6c.

[0190] Alternatively, the operation of the mechanical adjustment mechanism 23 shifts the front structure 6b relative to the linear guide configuration 14 to change the distance 24 between the front structure 6b and the rear structure 6c.

[0191] The electronic control system 6h is typically configured to control the operation of the adjusting actuator configuration 25, which is used to adjust the distance between the first mold portion 3a and the second mold portion 3b during a time period between consecutive pressing actions, so that the pressing member 6d provides a compressive force closer to the predetermined target pressing force during the next pressing cycle.

[0192] Figure 5 schematically illustrates the main processing steps of the pressing module 6 during normal operation. The pressing operation flow chart typically begins with the pressing member stationary in a standby position S associated with the retracting toggle mechanism and the opening of the pressing die 3, as schematically illustrated in Figure 4a. Upon receiving a command or instruction to start the pressing cycle, the second step F of the flow chart is executed, which involves activating the pressing actuator configuration 6f to push the pressing member 6d forward to F until the forming die 3 is closed and, in the third step P of the main process, a molding pressure of approximately 1-100 MPa (specifically 4-20 MPa) is applied to the cellulose preform structure. Subsequently, the fourth step R of the flow chart is executed, which involves initiating the return movement of the pressing member 6d to the starting position (i.e., standby position S).

[0193] In high-speed manufacturing, the process can skip step S, that is, skip the second step F of the flowchart before returning to the standby position S.

[0194] The term maximum stroke state, also known as “maximum extension operating position” as used herein, refers to the maximum forward position that can be obtained by the toggle mechanism when not obstructed by the molding die, cellulose preform structure or other components (e.g., the alignment of the first link member 18 and the second link member 19, as shown in Figure 4b).

[0195] In some specific examples, each of the first mold portion 3a and the second mold portion 3b includes a main rigid plate-like body having a typically substantially flat surface configured to face the other mold portion; and at least one pressing surface 3c, 3d defining one or more molding cavities C for molding the cellulose article 1, and having or not having additional fine components, such as spring-loaded cutting devices and / or mold alignment devices or the like, wherein these substantially flat surfaces of the main rigid plate-like bodies of the first mold forming portion 3a and the second mold forming portion 3b are not in direct contact with each other during the pressing cycle. Therefore, these surfaces of the main rigid plate-like bodies are not intended to contact each other and prevent further pressing movement of the first molding mold portion 3a and the second molding mold portion 3b. However, other parts of the first mold portion 3a and the second mold portion 3b may still contact each other during the pressing action, such as the spring-loaded cutting devices and / or mold alignment devices, which are not part of these surfaces of the first mold portion 3a and the second mold portion 3b.

[0196] Figures 8a and 8b schematically illustrate how the toggle press 6a can be adjusted using the mechanical adjustment mechanism 23 to obtain different levels of pressing force at the maximum extension actuation position. Figure 8c shows the case where the distance between the front structure 6b and the rear structure 6c is too small, and Figure 9 shows a schematic diagram of the resulting pressing force for each of these cases. The vertical axis in Figure 9 shows the pressing force provided by the toggle press 6a, and the horizontal axis in Figure 9 shows the distance 24 between the front structure 6b and the rear structure 6c of the toggle press 6a. When the distance 24 between the front structure 6b and the rear structure 6c is relatively short, the first and second linkage members of the toggle mechanism will still be misaligned when reaching the maximum pressing capacity of the toggle press 6a. When the distance 24 between the front structure 6b and the rear structure 6c is relatively large, the first and second linkage members of the toggle mechanism will easily reach the aligned position, but because the remaining die clearance 53 in the forming die 3 is relatively large, a large pressing force will not be generated at this position.

[0197] In Figure 8a, the distance 24 between the front structure 6b and the rear structure 6c is adjusted to be relatively long, thereby providing a relatively low pressing force when the pressing member 6d reaches its maximum extension actuation position. In this specific example, the maximum extension actuation position of the toggle mechanism 6e is obtained when the first link member 18 and the second link member 19 are aligned. The pressing force obtained at this adjusted position of the mechanical adjustment mechanism 23 is marked with point A in Figure 9.

[0198] In Figure 8b, the distance 24 between the front structure 6b and the rear structure 6c is reduced, thereby providing a higher pressing force when the pressing member 6d reaches its maximum extension actuation position. The pressing force obtained at this adjusted position of the mechanical adjustment mechanism 23 is marked with point B in Figure 9.

[0199] When the distance 24 between the front structure 6b and the rear structure 6c is adjusted to be extremely short, it prevents the toggle mechanism 6e from reaching the force balance position, that is, the first link member 18 and the second link member 19 from being misaligned, as illustrated in Figure 8c. The pressing force obtained at this adjustment position of the mechanical adjustment mechanism 23 is marked with point C in Figure 9.

[0200] The pressing operation of the pressing module 6 can be performed in a variety of ways. For example, the toggle press 6a can operate in an open-loop manner, in which feedback of parameters such as pressing force or pressing component position is not required.

[0201] Figure 10a schematically illustrates a specific example of a control system 40 suitable for controlling the toggle press 6a in an open-loop manner. In this specific example, the pressing actuator is configured as a hydraulic cylinder 6f, which is fluidly controlled by a solenoid-operated directional control valve 41, which is fluidly connected to a variable displacement hydraulic pump 42 and a reservoir 43. Furthermore, a feed device 16, in the form of an electric motor, is provided for controlling the operation of the forming line 4c, and a pressing member position detection device 44 is provided to ensure that the pressing member is operated to reach the maximum forward position of the toggle mechanism 6e at each pressing event. The operating state of the directional control valve 41 and the speed control of the feed device 16 can be controlled by an electronic control system 6h to provide the desired intermittent feed of the forming line 4c between subsequent pressing operations of the toggle press 6a.

[0202] The pressing member position detection configuration may be, for example, a linear position encoder configured to detect the position of the pressing member 6d, or a position encoder for detecting the actuation position of the toggle mechanism 6e, or a position encoder for detecting the actuation position of the pressing actuator configuration 6f, or the like.

[0203] According to an alternative control strategy, the control system 40 can be configured to control the toggle press 6a in a closed-loop manner, as schematically shown in Figure 10b. According to this control strategy, the pressing actuator configuration 6f can be controlled to simply displace the pressing member 6d to its maximum forward position, i.e., a 180-degree alignment angle or the maximum stroke state of the toggle mechanism 6e, and to pre-adjust the distance 24 between the front structure 6b and the rear structure 6c of the toggle press 6a so that the obtained pressing force equals the target pressing force. The electronic control system 6h can be configured to control the pressing operation based on feedback data from the pressing force detection or indication configuration, and to adjust the distance 24 between the front structure 6b and the rear structure 6c of the toggle press 6a between consecutive pressing operations to maintain the obtained pressing force at the target pressing force. Thus, variations in process parameters can be better handled to ensure improved quality of the cellulose product 1.

[0204] In addition to the features described with reference to FIG10a, FIG10b also shows an adjustment actuator configuration 25 configured to drive the mechanical adjustment mechanism 23. The adjustment actuator configuration 25 may be, for example, an electric or hydraulic motor. Furthermore, the system of FIG10b also shows a pressure detection device 6g for providing feedback to the electronic control system 6h.

[0205] Therefore, in some specific instances, the toggle press 6a further includes a pressure indication configuration 6g, wherein an electronic control system 6h is operably connected to the pressure indication configuration 6g and configured to control the operation of the press actuator configuration 6f based on pressure indication feedback information received from the pressure indication configuration 6g.

[0206] The pressure indication configuration 6g typically includes a certain type of measuring device for measuring the level of the pressure parameter. Therefore, the pressure indication feedback information typically includes or originates from the measurement process variables of the toggle press 6a.

[0207] The operation control of the press actuator configuration 6f based on the press pressure indication feedback information received by the self-press pressure indication configuration 6g can, for example, be designed as press pressure feedback control, position feedback control, or open-loop control with automatic self-tuning between consecutive pressing cycles.

[0208] The pressure indication configuration may correspond, for example, to one or more pressure sensors of a certain type located at one or more suitable locations on the pressing module 6. For example, a force gauge such as a strain gauge force sensor or the like may be provided at or inside the molding die 3, or between the toggle mechanism 6e and the rear structure 6c, or between the toggle mechanism 6e and the molding die 3.

[0209] Alternatively, or in combination with the above, the pressure indication configuration may correspond to a deformation sensor, such as a strain gauge sensor, configured to sense the deformation of, for example, one, two, or all of the tie rods in the intermediate linear guide configuration 14. Alternatively, deformation sensors, such as strain gauge sensors, laser sensors, etc., may be provided to detect the deformation of the front structure 6b or the rear structure 6c or the pressing member 6d or the toggle mechanism 6e.

[0210] In some specific instances, the electronic control system can be configured to control and adjust the actuator configuration 25, for example, to adjust the maximum pressing force of the toggle press for a specific cellulose preform structure.

[0211] Therefore, the toggle press may include a pressure indication configuration 6g, and an electronic control system 6h may be operably connected to the pressure indication configuration 6g. The control system may be configured to control the operation of the actuator configuration based on pressure indication feedback information received from the pressure indication configuration 6g, to adjust the distance between the front and rear structures along the pressing direction during the time interval between continuous pressing actions. Thus, the electronic control system can adjust the maximum pressing force.

[0212] The above situation is achieved, for example, by the following operation: during the first pressing cycle, the pressing pressure indication configuration 6g receives pressing pressure indication feedback information, determines whether the current operating position of the toggle press (i.e., the distance 24 between the front structure 6b and the rear structure 6c) is properly adjusted, and if not, the distance 24 between the front structure 6b and the rear structure 6c is adjusted by adjusting the appropriate operation of the actuator configuration 25, so that the operating position and / or pressing pressure during the next pressing cycle is more consistent with the target operating position and / or pressing pressure. In other words, the electronic control system does not need to actively control and adjust the input force on the toggle mechanism 6e provided by the pressing actuator configuration 6f to adapt to the pressing pressure of the pressing member 6d, but can instead rely solely on actively controlling and adjusting the actuator configuration 25.

[0213] This control strategy can be implemented by adjusting the distance 24 between the front structure 6b and the rear structure 6c, so that the toggle pressing module 6 reaches the target pressing force at the same time as reaching the maximum stroke state of the toggle mechanism 6e. In other words, the electronic control system is configured to obtain pressing force indication information from the pressing force indication configuration 6g during the normal pressing action of the toggle press 6a, and when, for example, the pressing force indication information indicates that the pressing force PF continuously exceeds the target pressing force within a set of pressing cycles, the distance 24 between the front structure 6b and the rear structure 6c of the toggle press 6a will be adjusted during the continuous pressing action so that the obtained pressing force is equal to the target pressing force.

[0214] According to an alternative example of the article forming unit U of the present invention, various forms of the article forming unit U may have another design, function and / or layout, as schematically illustrated in FIG11.

[0215] For example, the forming line 4c can extend all the way to the pressing module 6, thereby effectively eliminating the need for the intermediate feeding device 16.

[0216] Furthermore, the forming section 4d of the forming line 4c can be configured to extend in the horizontal direction DH. In this specific example, the cellulose preform structure 2 is air-formed on the forming section 4d and conveyed from the forming section 4d in the horizontal direction DH by the forming line 4c. After the cellulose preform structure 2 is formed onto the forming section 4d, the formed cellulose preform structure 2 is conveyed from the forming section 4d in the horizontal direction DH and further toward the pressing module 6.

[0217] Furthermore, the blank dry forming module 4 illustrated in Figure 11 has a vertical distribution direction of cellulose fibers F from the grinder 4a to the forming line 4c via the forming chamber 4b. Therefore, a vertical airflow feeds the cellulose fibers F from the grinder 4a to the forming section 4d.

[0218] In addition, the pressing direction DP of the toggle press 6a is configured to be perpendicular to the pressing direction DV of the pressing member 6d.

[0219] Using a toggle-type pressing module to form non-flat cellulose products from air-formed cellulose preforms offers many advantages over conventional, high-capacity, toggle-less hydraulic presses, such as lower cost, lighter weight, faster cycle time, and compactness. Therefore, the toggle-type pressing module 6 can be a useful alternative to conventional vertical standing hydraulic presses in certain situations.

[0220] The toggle-joint pressing module 6 schematically shown in Figures 12a and 12b corresponds to the toggle-joint pressing module 6 described above with reference to Figures 4a and 4b, and details regarding the toggle-joint pressing module 6 can be found in the disclosure relating to Figures 4a and 4b, except that the pressing actuator configuration 6f is schematically implemented here as an electric ball screw linear actuator. The ball screw linear actuator may, for example, include a rod 50 that is driven to an electric motor and has a helical track for holding a rolling ball that can circulate in the track in the crosshead 20.

[0221] The basic steps of a method for forming a non-flat cellulose article from an air-formed cellulose preform structure in an article forming unit U are described below with reference to FIG. 13. The article forming unit U includes a preform dry forming module 4 having a movable forming line 4c, an elbow pressing module 6 having an elbow press 6a and a forming die 3, and an electronic control system 6h operably connected to the forming line 4c and the elbow pressing module 6; wherein the elbow press 6a includes a pressing member 6d movably configured along the pressing direction, an elbow mechanism 6e driven to the pressing member 6d, and a pressing actuator configuration 6f driven to the elbow mechanism 6e; and wherein the forming die 3 includes a movable first die portion 3a and a second die portion 3b attached to the pressing member 6d. The method includes a first step S1 of air-forming a cellulose preform structure 2 onto the forming line 4c by means of the preform dry forming module 4. The method further includes a second step S2 of feeding the air-formed cellulose preform structure 2 into a pressing area defined by a spaced-apart first mold portion 3a and a second mold portion 3b. Furthermore, the method includes a third step S3 of controlling the operation of the pressing actuator configuration 6f by means of an electronic control system 6h to perform a pressing operation, which involves driving the pressing member 6d along the pressing direction by means of a toggle mechanism 6e, thereby forming a non-flat cellulose article from the air-formed cellulose preform structure by pressing the first mold portion 3a against the second mold portion 3b. Finally, the method includes a fourth step S4 of controlling the operation of the forming line 4c by means of the electronic control system 6h to intermittently feed the forming line 4c between subsequent pressing operations.

[0222] The fourth step S4 of controlling the operation of the press actuator configuration 6f can be performed in many different ways, while still solving the problem of forming non-flat cellulose products from air-formed cellulose preform structures using a low-cost, compact and lightweight cellulose product press module.

[0223] Referring to Figure 14, according to some specific examples, the toggle press 6a further includes: a pressure indication configuration 6g; an adjustment mechanism 23, which enables the adjustment of the distance between the first mold portion 3a and the second mold portion 3b in the pressing direction while keeping the toggle mechanism 6e in a non-moving operating state; and an adjustment actuator configuration 25, which is configured to drive the adjustment mechanism 23. Then, in addition to steps S1 to S4 described with reference to Figure 13, the method further includes a fifth step S5 of controlling the operation of the adjustment actuator configuration 25 based on the pressure indication feedback information received from the pressure indication configuration 6g.

[0224] Specifically, the fifth step S5 of controlling and adjusting the operation of the actuator configuration 25 may involve adjusting the distance between the first mold portion 3a and the second mold portion 3b during a time period between consecutive pressing actions, so that the target system of the pressing member 6d provides a compressive force closer to the predetermined target pressing force during the next pressing cycle.

[0225] The feedback controller 6h can be implemented in various alternative ways known to those skilled in the art, such as, for example, a P controller, a PI controller, a PID controller, optimal control, such as, for example, a linear quadratic (LQ) controller or the like.

[0226] For example, a PID (Proportional-Integral-Derivative) controller is a control loop structure that uses feedback to provide continuous modulated control of the process to be controlled. The feedback controller (such as a PID controller) continuously calculates an error value as the difference between the desired setpoint (SP) and the measured process variable (PV), and applies corrections based on the proportional, integral, and derivative terms of this error value. The setpoint (SP) can be, for example, a specific predetermined compression force, and the measured process variable (PV) can be, for example, the measured pressing force, such as that detected by a strain gauge force sensor located on the pull rod 37 of the toggle press 6a.

[0227] The elbow-shaped pressing module 6 for cellulose articles according to the present invention is also extremely useful for molding non-flat cellulose articles 1 from air-formed cellulose preform structures 2, even without the intermittent operation process of the forming line 4c of the preform dry forming module 4. Therefore, in an elbow-shaped pressing module for cellulose articles having a buffer disposed between the preform dry forming module 4 and the pressing module 6, and wherein the preform dry forming module 4 and the associated forming line 4c operate continuously at more or less constant operating speeds, the elbow-shaped pressing module for cellulose articles according to the present invention can still deliver various advantageous features, such as compactness, cost-effectiveness, and fast operating cycles.

[0228] The above-described scenario is provided, for example, by a toggle-joint pressing module 6 for molding a non-flat cellulose article 1 from an air-formed cellulose preform structure 2. The toggle-joint pressing module 6 includes a toggle-joint presser 6a, which includes a pressing member 6d movably configured along the pressing direction; a toggle mechanism 6e driven to the pressing member 6d; and a pressing actuator configuration 6f driven to the toggle mechanism 6e for controlling the movement of the toggle mechanism between a retracted operating position and an extended operating position. The toggle-joint pressing module 6 further includes: a molding die 3 including a movable first die portion 3a and a second die portion 3b attached to the pressing member 6d; an adjustment mechanism 23 for adjusting the distance between the first die portion 3a and the second die portion 3b along the pressing direction while the toggle mechanism 6e is in a non-moving operating state; and an adjustment actuator configuration 25 configured to drive the adjustment mechanism 23. The toggle-joint pressing module 6 further includes a pressing pressure indicator configuration 6g and an electronic control system 6h operably connected to the pressing pressure indicator configuration 6g, the pressing actuator configuration 6f, and the adjusting actuator configuration 25. The electronic control system 6h is configured to control the operation of the pressing actuator configuration 6f to drive the pressing member 6d in the pressing direction by setting the toggle mechanism 6e in the extended operating position, thereby pressing the first mold portion 3a against the second mold portion 3b to form a non-flat cellulose product from the air-formed cellulose preform structure. The electronic control system is also configured to control the operation of the adjusting actuator configuration 25 based on the pressing pressure indication feedback information received from the pressing pressure indicator configuration 6g.

[0229] Similarly, the present invention includes a corresponding method for forming non-flat cellulose articles from an air-formed cellulose preform structure in a toggle pressing module 6. A suitable toggle-joint pressing module 6 includes: a toggle press 6a, which includes a pressing member 6d movably configured along the pressing direction; a toggle mechanism 6e driven to the pressing member 6d; a pressing actuator configuration 6f driven to the toggle mechanism 6e to control the movement of the toggle mechanism between a retracted operating position and an extended operating position; a forming die 3, which includes a movable first die portion 3a and a second die portion 3b attached to the pressing member 6d; an adjustment mechanism 23 for adjusting the distance between the first die portion 3a and the second die portion 3b along the pressing direction while the toggle mechanism 6e is in a non-moving operating state; an adjustment actuator configuration 25 configured to drive the adjustment mechanism 23; a pressing pressure indication configuration 6g; and an electronic control system 6h operably connected to the pressing pressure indication configuration 6g, the pressing actuator configuration 6f, and the adjustment actuator configuration 25. The method includes: air-forming a cellulose preform structure 2 onto a forming line 4c using a preform dry forming module 4; feeding the air-formed cellulose preform structure 2 into a pressing area defined by a spaced-apart first mold portion 3a and second mold portion 3b; controlling the operation of a pressing actuator assembly 6f to perform a pressing operation, which involves driving a pressing member 6d in the pressing direction by setting a toggle mechanism 6e in an extended operating position, thereby pressing the first mold portion 3a against the second mold portion 3b to form a non-flat cellulose article from the air-formed cellulose preform structure; and controlling the operation of an adjusting actuator assembly 25 based on pressing indication feedback information received from a pressing pressure indication assembly 6g.

[0230] Adjusting the distance between the first mold part 3a and the second mold part 3b along the pressing direction while keeping the toggle mechanism 6e in a non-moving operating state means that the adjustment is not caused by the movement of the toggle mechanism, but by some other features.

[0231] Furthermore, the step of controlling the operation of the pressing actuator configuration to drive the pressing member in the pressing direction by setting the toggle mechanism in the extended operating position typically includes setting the toggle mechanism in the maximum extended operating position.

[0232] It should be understood that the above description is merely illustrative in nature and is not intended to limit the invention, its application, or its uses. Although specific examples are described in the specification and illustrated in the drawings, those skilled in the art will understand that various changes can be made and elements can be substituted with equivalents without departing from the scope of the invention as defined in the claims. Furthermore, features of the specific examples described herein can be combined with features of other specific examples described herein. Moreover, modifications can be made to adapt particular situations or materials to the teachings of the invention without departing from its essential scope. Therefore, the invention is not intended to be limited to specific examples illustrated in the drawings and described in the specification as the best mode currently contemplated for carrying out the invention, but rather the scope of the invention will include any specific examples falling within the foregoing description and the appended claims. Reference numerals used in the claims should not be considered as limiting the scope of the claims, and their sole purpose is to facilitate understanding of the claims.

[0233] 1: Cellulose products 2: Cellulose preform structure 2b: Cellulose preform 2c: Residual part 3: Molding mold 3a: First mold part 3b: Second mold part 4: Dry forming module for billets 4a: Grinding machine 4b: Molding chamber 4c: Molding line 4d: Forming section 4e: Molding chamber opening 4f: Vacuum chamber 5: Drive motor of the forming line 6: Pressing module 6a: Toggle Press 6b: Front structure 6c: Rear structure 6d: Pressing component 6e: Toggle Mechanism 6f: Press-actuator configuration 6g: Configure according to pressure indication 6h: Electronic control system 7: Billet recycling module 7a: Feeding structure 7b: Recycling Compaction Unit 9: Billet feed roller 10: Actuator 11: Intermediate Roller 13: Installation angle of the toggle press 14: Linear Guidance Configuration 15: Pressing area 16: Feeding device 17: Extension direction of the feeding device 18: First connecting rod component 18a: First pivoting connector 18b: Second pivoting connection 18c: Third pivot connector 18d: Longitudinal direction 19: Second Linkage Member 19a: First pivoting connector 19b: Second pivoting connection 19d: Longitudinal direction 20: Crosshead 21: Crosshead connecting rod component 21a: First connector 21b: Second connector 22: Alignment Angle 23: Mechanical Adjustment Mechanism 24: Distance between the front and rear structures 25: Adjust actuator configuration 26a: Gear 26b: Gear 26c: Gear 26d: Gear 27: Single-center gear 28: Maximum pressing pressure curve 29: Mold Clearance 30: Operation Window 31: Center pressing pressure - die clearance curve 32: Right side pressing pressure-mold clearance curve 33: Left side pressing pressure - mold clearance curve 34: First Arrow 35: Asymptotic region 36: Second arrow 37: Pull rod 38: Supporting Frame 39: Power Supply 40: Control System 41: Valve 42: Pump 43: slot 44: Location Detection Device 46: First pressing pressure - mold clearance curve 47: Second pressing pressure-mold clearance curve 48: Collect configuration 49: Feed Angle 50: Threaded rod 51: Buffer Configuration 53: Mold clearance 54a: First independent toggle mechanism 54b: Second separate toggle mechanism 55: Stepwise reduction C: Molding cavity DF1: First feed direction DF2: Second feed direction DH: Horizontal direction DP: Pressing direction DU: Upward blank forming direction DV: Vertical direction E: Deformable element F: Fiber MCONT: Continuous Flow Mode MF: Feed Mode MINT: Intermittent Flow Mode N: Maximum pressing force of the instance PF: Pressing force PFT: Target Pressure PNEG: Negative Pressure R: Cellulose raw material S1: First side S2: Second side t1: First time period t2: Second time period t3: Third time period t4: Fourth time period t5: Total time period TF: Molding temperature U: Product forming unit VI: Input Speed VO: Output speed VP: Operation Speed VW: Operating speed

Claims

1. A product forming unit (U) for manufacturing a non-flat cellulose product (1) from an air-formed cellulose preform structure (2), wherein the product forming unit (U) comprises a preform dry forming module (4) having a movable forming line (4c), an elbow pressing module (6) having an elbow press (6a) and a forming die (3), and an electronic control system (6h) operably connected to the forming line (4c) and the elbow press (6a); wherein the preform dry forming module (4) is configured to air-form the cellulose preform structure (2) onto the forming line (4c); wherein the elbow press (6a) comprises a pressing member (6d) movably configured along a pressing direction, an elbow mechanism (6e) driven to the pressing member (6d), and a pressing actuator configuration (6f) driven to the elbow mechanism (6e); The molding die (3) includes a movable first die portion (3a) and a second die portion (3b) attached to one of the pressing members (6d); the electronic control system (6h) is configured to control the operation of the pressing actuator configuration (6f) to perform a pressing operation, which involves driving the pressing member (6d) in the pressing direction by means of the toggle mechanism (6e), and thereby forming the non-flat cellulose article from the air-formed cellulose preform structure by pressing the first die portion (3a) against the second die portion (3b); and the electronic control system (6h) is further configured to intermittently feed the forming line (4c) between subsequent pressing operations.

2. The article forming unit (U) of claim 1, wherein the toggle press (6a) is installed or configured to be installed such that the pressing direction of the pressing member (6d) is mainly arranged in a horizontal direction.

3. The article forming unit (U) as claimed in claim 1 or 2, wherein the toggle press (6a) further includes: The system includes a pressure indicator configuration (6g), an adjustment mechanism (23) for adjusting a distance between the first mold portion (3a) and the second mold portion (3b) along the pressing direction while keeping the toggle mechanism (6e) in a non-moving operating state, and an adjustment actuator configuration (25) configured to drive the adjustment mechanism (23). The electronic control system (6h) is operably connected to the pressure indicator configuration (6g) and configured to control the operation of the adjustment actuator configuration (25) based on pressure indicator feedback information received from the pressure indicator configuration (6g).

4. The article forming unit (U) of claim 3, wherein the electronic control system (6h) is configured to control the operation of the adjusting actuator configuration (25) to adjust the distance between the first mold portion (3a) and the second mold portion (3b) during a time period between consecutive pressing actions, such that during the next pressing cycle, the pressing member (6d) aims to provide a compressive force closer to a predetermined target pressing force.

5. The article forming unit (U) of claim 3, wherein the pressure indication configuration (6g) includes one or more of the following sensors: a force gauge, a deformation sensor, or a strain gauge force sensor, and wherein the one or more sensors are located at or within the forming mold (3), or on the toggle mechanism (6e), or between the toggle mechanism (6e) and a rear structure (6c) of a rigid frame structure of the toggle press (6a), or between the toggle mechanism (6e) and the forming mold (3), or at the rigid frame structure of the toggle press (6a), or at a pull rod of an intermediate linear guide configuration (14) of the toggle press (6a).

6. The article forming unit (U) of claim 1 or 2, wherein the blank dry forming module (4) further includes a grinding mill (4a) and a forming chamber (4b), wherein the forming line (4c) is configured to be connected to the forming chamber (4b), wherein the grinding mill (4a) is configured to separate fibers (F) from a cellulose raw material (R), wherein the forming chamber (4b) is configured to distribute the separated fibers (F) onto a forming section (4d) of the forming line (4c) to form the cellulose blank structure (2).

7. The article forming unit (U) of claim 1 or 2, wherein the article forming unit (U) further includes a cellulose preform feeding device (16), specifically a conveyor belt and / or a set of feed rollers configured to convey the air-formed cellulose preform structure (2) from the forming line (4c) of the preform dry forming module (4) to the forming mold (3) of the elbow pressing module (6), wherein the electronic control system (6h) is configured to provide substantially synchronous operation of the forming line (4c) and the conveying device (16).

8. The article molding unit (U) of claim 1 or 2, wherein the molding die (3) is configured to form the cellulose article (1) from the cellulose preform structure (2) by: heating the cellulose preform structure (2) to a molding temperature in the range of 100-300°C, and pressing the cellulose preform structure (2) with a molding pressure in the range of 1-100 MPa, preferably 4-20 MPa.

9. The article forming unit (U) of claim 1 or 2, wherein the article forming unit further includes a blank recycling module (7) configured to transport the residual portion of the cellulose blank structure from the pressing module (6) to the blank dry forming module (4).

10. The article forming unit (U) of claim 1 or 2, wherein the article forming unit (U) is adapted to intermittently feed the cellulose preform structure (2) from the preform dry forming module (4) along a first feeding direction by means of the forming line (4c), and is adapted to intermittently feed the cellulose preform structure (2) to the pressing module (6) along a second feeding direction, wherein the second feeding direction is different from the first feeding direction, specifically, wherein the second feeding direction is opposite to or substantially opposite to the first feeding direction.

11. The article forming unit (U) of claim 1 or 2, wherein the first feeding direction is an upward direction and the second feeding direction is a downward direction.

12. A method for molding a non-flat cellulose article from an air-formed cellulose preform structure in an article forming unit (U), the article forming unit comprising a preform dry forming module (4) having a movable forming line (4c), a toggle pressing module (6) having a toggle press (6a) and a forming die (3), and an electronic control system (6h) operably connected to the forming line (4c) and the toggle pressing module (6); wherein the toggle press (6a) includes a pressing member (6d) movably configured along a pressing direction, a toggle mechanism (6e) driven to the pressing member (6d), and a pressing actuator configuration (6f) driven to the toggle mechanism (6e); wherein the forming die (3) includes a movable first die portion (3a) and a second die portion (3b) attached to the pressing member (6d); and wherein the method comprises: A cellulose preform structure (2) is air-formed onto the forming line (4c) using the preform dry forming module (4). The air-formed cellulose preform structure (2) is fed into a pressing area defined by the spaced-apart first mold portion (3a) and second mold portion (3b). The operation of the pressing actuator configuration (6f) is controlled by the electronic control system (6h) to perform a pressing operation, which involves driving the pressing member (6d) along the pressing direction by means of the toggle mechanism (6e), thereby forming the non-flat cellulose article from the air-formed cellulose preform structure by pressing the first mold portion (3a) against the second mold portion (3b), and controlling the operation of the forming line (4c) by means of the electronic control system (6h) to intermittently feed the forming line (4c) between subsequent pressing operations.

13. The method of claim 12, comprising controlling the operation of the molding line (4c) by means of the electronic control system (6h) to intermittently feed the molding line (4c) between subsequent pressing operations, such that the molding line (4c) operates periodically at a relatively high speed during the time period between subsequent pressing operations and at a relatively low speed or zero speed during the time period concurrent with the pressing operation.

14. The method of claim 12 or 13, wherein the toggle press (6a) further comprises: A pressure indication configuration (6g); an adjustment mechanism (23) for adjusting a distance between the first mold portion (3a) and the second mold portion (3b) along the pressing direction while the toggle mechanism (6e) is in a non-moving operating state; and an adjustment actuator configuration (25) configured to drive the adjustment mechanism (23), wherein the method includes controlling the operation of the adjustment actuator configuration (25) based on pressure indication feedback information received from the pressure indication configuration (6g).

15. The method of claim 14, wherein the method comprises controlling the operation of the adjusting actuator configuration (25) to adjust the distance between the first mold portion (3a) and the second mold portion (3b) during a time period between consecutive pressing actions, such that during the next pressing cycle, the target of the pressing member (6d) provides a compressive force closer to a predetermined target pressing force.

16. The method of claim 12 or 13, wherein the step of air-forming the cellulose preform structure (2) from cellulose raw material (R) in the preform dry forming module (4) involves: separating fibers (F) from the cellulose raw material (R) in a mill (4a), distributing the separated fibers (F) onto a forming line (4c) of the preform dry forming module (4) to form the cellulose preform structure (2), and conveying the formed cellulose preform structure (2) along an upward preform forming direction (DU).

17. The method of claim 12 or 13, wherein the cellulose preform structure (2) is intermittently conveyed from the preform dry forming module (4) along a first feed direction (DF1) by the forming line (4c) and intermittently conveyed to the pressing module (6) along a second feed direction (DF2), wherein the second feed direction (DF2) is different from the first feed direction (DF1), specifically, wherein the second feed direction (DF2) is opposite or substantially opposite to the first feed direction (DF1).

18. The method of claim 12 or 13, wherein the step of forming the cellulose articles (1) from the cellulose preform structure (2) in the molding die (3) involves heating the cellulose preform structure (2) to a molding temperature in the range of 100-300°C and pressing the cellulose preform structure (2) with a molding pressure in the range of 1-100 MPa, preferably 4-20 MPa.

19. A toggle press module (6) for molding a non-flat cellulose article (1) from an air-formed cellulose preform structure (2), the toggle press module (6) comprising: a toggle press (6a) including a pressing member (6d) movably configured along a pressing direction, a toggle mechanism (6e) driven to the pressing member (6d), a press actuator configuration (6f) driven to the toggle mechanism (6e) to control the movement of the toggle mechanism between a retracted operating position and an extended operating position, and a molding die (3) including a movable first die portion (3a) and a second die portion (3b) attached to one of the pressing members (6d). An adjustment mechanism (23) for adjusting a distance between the first mold portion (3a) and the second mold portion (3b) along the pressing direction while the toggle mechanism (6e) is in a non-moving operating state; an adjustment actuator configuration (25) configured to drive the adjustment mechanism (23); a pressing pressure indicator configuration (6g); and an electronic control system (6h) operably connected to the pressing pressure indicator configuration (6g), the pressing actuator configuration (6f), and the adjustment actuator configuration (25). The electronic control system (6h) is configured to control the operation of the press actuator configuration (6f) to drive the press member (6d) in the pressing direction by setting the toggle mechanism (6e) in the extended operating position, and thereby forming the non-flat cellulose article from the air-formed cellulose preform structure by pressing the first mold portion (3a) against the second mold portion (3b); and the electronic control system is configured to control the operation of the adjustment actuator configuration (25) based on the press indication feedback information received from the press pressure indication configuration (6g).

20. The article forming unit (U) of claim 19, wherein the electronic control system (6h) is configured to control the operation of the adjusting actuator configuration (25) to adjust the distance between the first mold portion (3a) and the second mold portion (3b) during a time period between consecutive pressing actions, such that during the next pressing cycle, the pressing member (6d) aims to provide a compressive force closer to a predetermined target pressing force.

21. A method for molding a non-flat cellulose article from an air-formed cellulose preform structure in a toggle press assembly (6), the toggle press assembly comprising: a toggle press (6a) including a pressing member (6d) movably configured along a pressing direction, a toggle mechanism (6e) driven to the pressing member (6d), a press actuator configuration (6f) driven to the toggle mechanism (6e) to control the movement of the toggle mechanism between a retracted operating position and an extended operating position, and a molding die (3) including a movable first die portion (3a) and a second die portion (3b) attached to one of the pressing members (6d). An adjustment mechanism (23) for adjusting a distance between the first mold portion (3a) and the second mold portion (3b) along the pressing direction while keeping the toggle mechanism (6e) in a non-moving operating state, and an adjustment actuator configuration (25) configured to drive the adjustment mechanism (23), a pressing pressure indicator configuration (6g), and an electronic control system (6h) operably connected to the pressing pressure indicator configuration (6g), the pressing actuator configuration (6f), and the adjustment actuator configuration (25), wherein the method comprises: air-forming a cellulose preform structure (2) onto the forming line (4c) by means of the preform dry forming module (4), and feeding the air-formed cellulose preform structure (2) into a pressing area defined by the spaced-apart first mold portion (3a) and second mold portion (3b). Controlling the operation of the pressing actuator configuration (6f) to perform a pressing operation involves driving the pressing member (6d) in the pressing direction by setting the toggle mechanism (6e) in the extended operating position, and thereby forming the non-flat cellulose article from the air-formed cellulose preform structure by pressing the first mold portion (3a) against the second mold portion (3b), and controlling the operation of the adjusting actuator configuration (25) based on the pressing indication feedback information received from the pressing pressure indication configuration (6g).

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