Method for producing a container made of material comprising fibres

Abstract

The present invention relates to a method for producing a container from fiber-comprising material by means of a device comprising a mold with a cavity for receiving an aqueous solution comprising the fibers and a first device for letting the aqueous solution flow into the mold and for pressurizing the mold, wherein the method comprises a flow of the fibers onto an inner surface of the cavity, wherein the first device for the flow comprises a supply line to an opening of the cavity of the mold, into which the aqueous solution is introduced into the mold via a first valve, and wherein the first device applies an overpressure to the supply line so that the fibers are pressed against the inner surface of the cavity to form the container.According to the invention, it is provided that the first valve is closed and the overpressure is applied to the supply line before an entirety of the fibers, which form a fiber component of the container, is located in the cavity.

Description

[0001] The present invention relates to a method for producing a container from fiber-comprising material according to claim 1 and to a device for producing a container from fiber-comprising material according to claim 14. State of the art

[0002] In recent decades, containers such as bottles in the beverage, cosmetics, and medical technology industries have been manufactured from glass or plastic materials, particularly PET. While these containers offer favorable properties for holding liquids, food, or medications, their production and use involve a high consumption of raw materials. Furthermore, the use of PET containers is not environmentally sustainable and is only possible through complex recycling processes.

[0003] Therefore, alternatives were proposed, such as using containers made from natural materials, especially fibrous materials like pulp, instead of plastic containers made from PET or similar materials.

[0004] In previous methods, an aqueous solution containing fibers is introduced into a mold with a cavity whose inner surface corresponds to the shape of the container to be produced. These fibers will form the container material upon completion. Subsequently, pressure is applied within the mold cavity, for example, by inserting a pressurized balloon or by introducing compressed air. This forces the liquid components of the aqueous solution out of the mold, simultaneously pressing the fiber material against the inner surface of the cavity, thus reducing variations in the container's wall thickness along its longitudinal axis.

[0005] However, these processes have in common that they require a relatively long time to manufacture the container. Task

[0006] Based on the known state of the art, the technical problem to be solved is therefore to specify a method and a device for manufacturing a container from fiber-containing material that allows for an acceleration of the manufacturing of the container. Solution

[0007] This problem is solved according to the invention by the method for manufacturing a container from fiber-comprising material according to claim 1 and the device for manufacturing a container from fiber-comprising material according to claim 14. Advantageous embodiments of the invention are described in the dependent claims.

[0008] The inventive method for producing a container from fiber-comprising material is carried out by means of a device comprising a mold with a cavity for receiving an aqueous solution comprising the fibers and a first device for letting the aqueous solution flow into the mold and pressurizing the mold, wherein the method comprises a flow of fibers onto an inner surface of the cavity, wherein the first device for the flow comprises a supply line to an opening of the cavity of the mold, into which the aqueous solution is introduced via a first valve, and wherein the first device applies an overpressure to the supply line so that the fibers are pressed against the inner surface of the cavity to form the container, and is characterized in that the first valve is closed and the overpressure is applied to the supply line before an entirety of the fibers,which form a fibrous component of the container in which there is a cavity.

[0009] The fibers can be, in particular, natural fibers and especially plant components, or they can comprise such components. Preferably, the fibers are at least partially pulp.

[0010] The aqueous solution need not be water-based; it can also be based on any other liquid solvent. Specifically, aqueous solutions introduced into the cavity can have a water or other liquid content exceeding 90% and a fiber content of less than 5% or even less than 1%. Additionally, the aqueous solution can contain other components, such as additives to influence the chemical or physical properties of the fibers.

[0011] The cavity of the mold is designed in such a way that the fibers do not penetrate the inner surface of the cavity and the liquid of the aqueous solution can be drained from it independently of the opening of the cavity.

[0012] This process can accelerate the production of the container. At the same time, it results in a very effective flow of fibers onto the inner surface of the cavity if they are introduced into the cavity at increased pressure towards the end of the flow.

[0013] It can be provided that a maximum of 99%, preferably a maximum of 95%, of the total fibers forming the fiber content of the container are located in the cavity before the first valve is closed and the overpressure is applied to the supply line. This results in an acceleration of the process.

[0014] Furthermore, it can be stipulated that the overpressure is applied at 0.1 to 10 bar. At this overpressure, the flow occurs effectively, resulting in a uniform distribution of the fibers. This pressure is also suitable for shaping the container on the inner surface of the cavity.

[0015] The mold can include a grid that forms at least part, preferably the entire, inner surface of the cavity. The grid can preferably contribute to retaining the solid components of the aqueous solution within the cavity of the mold.

[0016] In one embodiment, the mold is arranged such that the container is formed upside down and the opening is oriented downwards. This allows for a very effective flow of water to the bottom section of the container, since this flow occurs under overpressure.

[0017] Furthermore, it can be provided that a compressed air reservoir is connected to the supply line via a compressed air valve. Compressed air from the reservoir is fed into the mold via the valve and the supply line as soon as the first valve is closed and the compressed air valve is opened. The aqueous solution located in the supply line between the valve and the mold is then forced into the mold by the compressed air, thus completing the flow of the solution to the inner surface of the cavity containing the fibers. This efficiently ensures that all the fibers forming the fiber component of the container are exposed to the solution, resulting in the container being fully formed quickly and excess liquid being expelled.

[0018] The compressed air valve can be connected to the supply line downstream of the first valve in such a way that the section of the supply line between the compressed air valve and the opening fills with the aqueous solution when the first valve is open and the compressed air valve is closed. This allows for a simple design of the first device.

[0019] Furthermore, the section of the supply line can comprise a volume which, when filled with aqueous solution, contains at least 1%, preferably at least 5%, of the fibers of the total fibers that constitute the fiber content of the container.

[0020] It may be provided that the aqueous solution in the supply line has a solids mass fraction of 0.1 to 10%.

[0021] In one embodiment, a reservoir of the aqueous solution is connected to the first valve, the reservoir and the first valve being configured such that the aqueous solution, containing all the fibers that constitute the fiber portion of the container, flows through the first valve within 0.1 to 10 s, preferably within 0.3 to 2 s, when the valve is open. This enables rapid production of the container.

[0022] Furthermore, it can be provided that heat is introduced into the cavity at least temporarily during and / or after the application of overpressure to the supply line. This additionally removes excess liquid from the fibers exposed to the flow on the inner surface of the cavity.

[0023] It can also be provided that a centrifugal force is exerted on the aqueous solution in the cavity during the flow. This ensures a uniform distribution of the fibers and a reliable reduction of the liquid content within the cavity during the flow. Preferably, the grid is set into rotation to exert the centrifugal force on the aqueous solution. This is an energy-efficient way to exert the centrifugal force on the aqueous solution.

[0024] In one embodiment, the first valve is closed before the overpressure is applied. This ensures that no aqueous solution is forced back through the first valve. Preferably, the time interval between closing the first valve and applying the overpressure is a maximum of 10 seconds, more preferably a maximum of 2 seconds. This short time interval allows for rapid production of the container.

[0025] The device according to the invention for producing a container from fiber-containing material comprises a mold with a cavity for receiving an aqueous solution comprising the fibers and a first device for allowing the aqueous solution to flow into the mold and for pressurizing the mold, wherein the device is designed such that it is possible to allow the flow of fibers onto an inner surface of the cavity, wherein the first device for the flow has a supply line to an opening of the cavity of the mold, into which the aqueous solution can be directed via a first valve, and wherein the first device is designed such that an overpressure can be applied to the supply line so that the fibers can be pressed against the inner surface of the cavity to form the container.The device is characterized in that the device is set up such that the first valve is closed and the overpressure is applied to the supply line before an entirety of the fibers, which form a fiber component of the container, is located in the cavity.

[0026] This device can accelerate the production of the container. At the same time, its use also results in a very effective flow of fibers onto the inner surface of the cavity.

[0027] The device can be arranged such that a maximum of 99%, preferably a maximum of 95%, of the total fibers forming the fiber content of the container are located in the cavity before the first valve is closed and the overpressure is applied to the supply line.

[0028] The device can be set up such that the overpressure is applied at 0.1 to 10 bar.

[0029] The mold may include a grid that forms at least part, preferably completely, of the inner surface of the cavity.

[0030] Furthermore, it may be provided that the mold is arranged in such a way that the container is formed upside down and the opening is oriented downwards.

[0031] In one embodiment, it can be provided that a compressed air reservoir is connected to the supply line via a compressed air valve in such a way that compressed air from the compressed air reservoir is fed into the mold via the compressed air valve and the supply line as soon as the first valve is closed and the compressed air valve is opened, whereby the aqueous solution, which is located in a section of the supply line between the compressed air valve and the mold, is pushed into the mold by the compressed air and there completes the flow of the fibers onto the inner surface of the cavity.

[0032] It may be provided that the compressed air valve is connected to the supply line downstream of the first valve in such a way that the section of the supply line between the compressed air valve and the opening fills with the aqueous solution when the first valve is open and the compressed air valve is closed.

[0033] The section of the supply line can comprise a volume which, when filled with aqueous solution, contains at least 1%, preferably at least 5%, of the fibers of the total fibers that constitute the fiber content of the container.

[0034] Furthermore, it can be provided that a reservoir of the aqueous solution is connected to the first valve, wherein the reservoir and the first valve are designed such that aqueous solution comprising the entirety of the fibers forming the fiber portion of the container flows through the first valve within 0.1 to 10 s, preferably within 0.3 to 2 s, when the first valve is opened.

[0035] The device can be set up in such a way that heat is introduced into the cavity at least temporarily during and / or after the application of overpressure to the supply line.

[0036] Furthermore, the device can be configured such that a centrifugal force can be exerted on the aqueous solution in the cavity during the flow. Preferably, the device is configured such that the grid can be rotated to exert this centrifugal force on the aqueous solution.

[0037] The device can be configured such that the first valve closes before the overpressure is applied. Preferably, the device is configured such that the time interval between closing the first valve and applying the overpressure is a maximum of 10 s, preferably a maximum of 2 s. Brief description of the characters

[0038] Fig. 1a to 1e Schematic side view of an embodiment of the device for producing a container from fiber-containing material at different times of the method for producing the container from fiber-containing material according to one embodiment. Detailed description of the characters

[0039] Figs. 1a to 1e They show an embodiment of a method for producing a container from fiber-containing material by means of an embodiment of a device 100 for producing the container. The device 100 comprises a mold 101 with a cavity 102 for receiving an aqueous solution comprising the fibers and a first device 103 for letting the aqueous solution flow into the mold 101 and pressurizing the mold 101. The method includes letting the fibers flow onto an inner surface 104 of the cavity 101, which in the Figs. 1b to 1cThe first device 103 for the inflow comprises a supply line 105 to an opening 106 of the cavity 102 of the mold 101. The aqueous solution is introduced into the mold 101 via the supply line 105 and a first valve 107. The fibers then adhere to the inner surface 104 of the cavity 101, and the liquid aqueous solution is drained away. The drainage of the liquid is symbolized by black arrows in the figures. The device can, for example, have drain lines for this purpose. Furthermore, the first device 103 applies an overpressure to the supply line 105, as shown in the figures. Fig. 1c and 1d As shown, the fibers are pressed against the inner surface 104 of the cavity 102 to form the container. According to the invention, the first valve 107 is closed and the overpressure is applied to the supply line 105 before the entirety of the fibers, which form a fiber component of the container, are located in the cavity 102.

[0040] It can be provided that a maximum of 99%, preferably a maximum of 95%, of the total fibers forming the fiber content of the container are located in the cavity 102 before the first valve 107 is closed and the overpressure is applied to the supply line 105.

[0041] As shown in the figures, the mold 101 can include a grid 109 that forms the inner surface 104 of the cavity 102. The grid 109 is designed such that the fibers flowing into the cavity 102 with the aqueous solution are deposited on the grid 109, and the liquid aqueous solution exits the cavity 102 through it and is drained away. For this drainage, the mold can, for example, have several drainage channels (not shown).

[0042] Furthermore, a centrifugal force can be exerted on the aqueous solution in the cavity 102 during the flow of the aqueous solution, preferably by rotating the grid 109 to exert this centrifugal force on the aqueous solution. The centrifugal force transports the fibers to the inner surface 104 of the cavity, where they form the fiber structure of the container.

[0043] In the illustrated embodiment of the method, the mold 101 is arranged such that the container is formed upside down. This initiates the formation of the container with its side walls.

[0044] Furthermore, in the illustrated embodiment of the method, a compressed air reservoir (not shown) is connected via a compressed air valve 108 to the supply line 105 for generating the overpressure, wherein compressed air from the compressed air reservoir is fed via the compressed air valve 108 and the supply line 105 into the mold 101 as soon as the first valve 107 is closed and the compressed air valve 108 is opened, as shown in Figure 1c This is shown. The aqueous solution, located in a section of the supply line 105 between the compressed air valve 108 and the mold 101, is forced into the mold 101 by the compressed air, thus preventing the flow of fibers to the inner surface 104 of the cavity 102. The compressed air reservoir has an overpressure of 0.1 to 100 bar.

[0045] The compressed air valve 108 is connected downstream of the first valve 107 to the supply line 105, so that the section of the supply line 105 between the compressed air valve 108 and the opening 106 fills with the aqueous solution when the first valve 107 is open and the compressed air valve 108 is closed, as shown in Figure 1b shown.

[0046] The section of the supply line 105 therefore contains a certain number of fibers as part of the aqueous solution. When the first valve 107 is closed and the pressure valve 108 is opened, this portion of the fibers, along with the fibers currently located in the cavity 102, is drawn towards the inner surface 104 of the cavity or towards the grid 109. The compressed air ensures the distribution of the fibers. As soon as all the fibers, which constitute the fiber portion of the container, are in contact with the inner surface 104, the compressed air forces liquid out of the fibers, as described in Figure 1d is shown.

[0047] While compressed air is applied to the mold 101, heat can also be introduced into the cavity 102 via the mold 101, for example by a heating element that at least partially surrounds the cavity 102. This allows additional liquid to be removed from the fibers in contact with the inner surface 104.

[0048] After the in Fig. 1eAt the time shown, which is after the mold 101 has been pressurized, the first device 103 can be removed from the mold 101 and, for example, another device can be connected to the mold 101, which, for instance, applies an internal coating to the container. Alternatively, the mold 101 can be opened and the container removed. Meanwhile, the first device 103 can be connected to another mold 101 to repeat the process of applying the fluid and pressurizing it, or it can be reconnected to the same mold 101 once the container has been removed.

[0049] To achieve a high production rate, a reservoir of aqueous solution (not shown) can be connected to the first valve 107, wherein the reservoir and the first valve 107 can be configured such that aqueous solution comprising all the fibers forming the fiber portion of the container flows through the first valve 107 within 0.1 to 10 s, preferably within 0.3 to 2 s, when the first valve 107 is open. Furthermore, it can be provided that the first valve 107 is closed before the overpressure is applied, wherein the time interval between closing the first valve 107 and applying the overpressure is a maximum of X s, preferably a maximum of Y s.

Claims

1. A method for producing a container from fiber-comprising material by means of a device comprising a mold with a cavity for receiving an aqueous solution comprising the fibers and a first device for letting the aqueous solution flow into the mold and pressurizing the mold, wherein the method comprises letting the fibers flow onto an inner surface of the cavity, wherein the first device for letting the solution flow comprises a supply line to an opening of the cavity of the mold, into which the aqueous solution is introduced into the mold via a first valve, and wherein the first device applies an overpressure to the supply line so that the fibers are pressed against the inner surface of the cavity to form the container. characterized by the fact that the first valve is closed and the overpressure is applied to the supply line before the entirety of the fibers that form a fiber component of the container is located in the cavity.

2. Method according to claim 1, wherein a maximum of 99%, preferably a maximum of 95%, of the totality of the fibers forming the fiber content of the container are located in the cavity before the first valve is closed and the overpressure is applied to the supply line.

3. Method according to claim 1 or 2, wherein the overpressure is applied at 0.1 to 10 bar.

4. Method according to any one of claims 1 to 3, wherein the shape comprises a grid that forms at least partially, preferably completely, the inner surface of the cavity.

5. Method according to any one of claims 1 to 4, wherein the mold is arranged such that the container is formed upside down and the opening is oriented downwards.

6. Method according to any one of claims 1 to 5, wherein a compressed air reservoir is connected to the supply line via a compressed air valve, wherein compressed air from the compressed air reservoir is introduced into the mold via the compressed air valve and the supply line as soon as the first valve is closed and the compressed air valve is opened, wherein the aqueous solution, which is located in a section of the supply line between the compressed air valve and the mold, is pushed into the mold by the compressed air and there completes the flow of the fibers to the inner surface of the cavity.

7. Method according to claim 6, wherein the compressed air valve is connected to the supply line downstream of the first valve in such a way that the section of the supply line between the compressed air valve and the opening fills with the aqueous solution when the first valve is open and the compressed air valve is closed.

8. Method according to claim 6 or 7, wherein the section of the supply line comprises a volume which, when filled with aqueous solution, contains at least 1%, preferably at least 5%, of the fibers of the total amount of fibers that constitute the fiber content of the container.

9. A method according to any one of claims 1 to 8, wherein the aqueous solution in the feed line has a solids mass fraction of 0.1 to 10%.

10. A method according to any one of claims 1 to 9, wherein a reservoir of the aqueous solution is connected to the first valve, wherein the reservoir and the first valve are configured such that aqueous solution comprising the entirety of the fibers forming the fiber portion of the container flows through the first valve within 0.1 to 10 s, preferably within 0.3 to 2 s, when the first valve is open.

11. Method according to one of claims 1 to 10, wherein heat is introduced into the cavity at least temporarily during and / or after the application of overpressure to the supply line.

12. Method according to one of claims 1 to 11, wherein a centrifugal force is exerted on the aqueous solution in the cavity during the flow, wherein preferably the grid is set in rotation to exert the centrifugal force on the aqueous solution.

13. Method according to one of claims 1 to 12, wherein the first valve is closed before the overpressure is applied, wherein preferably a time interval between closing the first valve and applying the overpressure is a maximum of 10 s, preferably a maximum of 2 s.

14. Device for producing a container from a material comprising fibers, the device comprising a mold with a cavity for receiving an aqueous solution comprising the fibers and a first device for allowing the aqueous solution to flow into the mold and for pressurizing the mold, the device being configured such that it is possible to allow the flow of fibers onto an inner surface of the cavity, the first device for the flow having a supply line to an opening of the cavity of the mold into which the aqueous solution can be directed via a first valve, and the first device being configured such that an overpressure can be applied to the supply line so that the fibers can be pressed against the inner surface of the cavity to form the container. characterized by the fact thatThe device is set up such that the first valve is closed and the overpressure is applied to the supply line before the entirety of the fibers that form a fiber component of the container is located in the cavity.

15. Device according to claim 14, wherein the device is configured to perform a method according to any one of claims 2 to 14.

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