Method and apparatus for manufacturing a bio-degradable hollow article with a connecting element

Abstract

The invention relates to a method and a device for producing a container with a hollow body (1) made of fibrous material having an opening (2) and a connecting element (3) arranged on the hollow body and surrounding the opening (2). The object of the invention is to provide a method with a short process time and a low energy input. The method comprises the following method steps: - providing a partitioned suction mould (4) having a porous wall (5) that, in the closed state, surrounds at least one cavity (6) with a mould opening (7); - arranging the connecting element (3) on a holder (8) and inserting the holder (8) into the cavity (6) of the suction mould (4) in such a way that the holder (8) protrudes through the mould opening (7) and holds the connecting element (3) in the mould opening (7); - closing the partitioned suction mould (4) and sucking fibrous material from a pulp (13) through the wall (5) of the suction mould (4) in such a way that a hollow body (1) is formed between the holder (8) and the wall (5); - compacting the hollow body (1) with the connecting element (3) arranged thereon; and - drying the hollow body (1). To enable reliable handling of the hollow body, the hollow body (1) is removed from the partitioned suction mould (4) by the holder (8).

Description

Technical field

[0001] The invention relates to a method for manufacturing a container with a hollow body made of fibrous material having an opening and a connecting element arranged on the hollow body and surrounding the opening, according to the preamble of claim 1, in particular a method based on the fiber casting process. The invention also relates to a device for manufacturing a container according to the said method. State of the art

[0002] Molded pulp containers are used for various purposes, particularly as transport packaging and as molded inserts in packaging to protect sensitive goods. With the aim of further reducing the amount of plastic waste generated by packaging materials, the use of molded pulp containers for cosmetic and food products has also gained increasing attention. In particular, there is a desire to use hollow fibrous containers with a closable opening as jars for cosmetic products, such as creams, or as containers for food products, such as liquids. Achieving suitable mechanical properties and manufacturing such hollow fibrous containers present challenges.

[0003] Achieving suitable mechanical properties is particularly important in the area of ​​the hollow body's opening. Since the opening must be tightly sealable for use in cosmetic and food products, polymer sealing films and / or caps are regularly applied as closures. A secure bond between the closures and the hollow body is essential to prevent them from detaching uncontrollably. A secure bond for a sealing film can be achieved by gluing or welding it in place. A smooth surface to which the sealing film is applied is advantageous for this. A secure bond for caps can be achieved by firmly pushing or screwing them on. This requires high strength in both the caps and the area where they are attached, which is why the fibrous material is regularly reinforced.

[0004] To meet the aforementioned requirements, it is known in practice to provide containers as a combination of a fiber-reinforced body with an opening and a connecting element that reinforces the opening area. In practice, the connecting element of such a container can be injection-molded from a polymer and may have higher strength, higher hardness, and / or a smoother surface suitable for the adhesion of sealing films than the fiber material of the hollow body. Thus, a closure can easily be attached to the connecting element, which securely seals the opening of the hollow body (or container). The connecting element may also have special design details such as an external thread that engages with an internal thread of a screw-on closure.The applicant has developed a thermoplastic material consisting exclusively of biodegradable or bioinert components. If the connecting element and the closure of a container are made of biodegradable biopolymers, the entire container can be biodegradable.

[0005] The production of these containers is currently complex. In known manufacturing processes, the fiber-shaped body is first produced using a fiber casting process. The connecting element is manufactured separately and joined to the dried fiber-shaped body either by positive locking or by material bonding. Alternatively, the connecting element can be injection-molded onto the dried fiber-shaped body.

[0006] For example, EP 1 221 413 A1 discloses a container with a fiber-shaped body that has a resin layer on its inner and / or outer surface, formed by applying a coating, whereby a specific thickness ratio of the resin layer to the shaped object is achieved and the inner and outer surfaces have an average centerline roughness (Ra) of 0.5 to 20 µm. The fiber-shaped body is formed in a multi-step process. First, pulp is poured into a cavity of a split mold. The water from the pulp is drawn off through mesh-covered holes in the wall of the split mold, thereby forming the fiber-shaped body on the wall. Subsequently, an elastic and expandable press tool is inserted into the cavity of the fiber-shaped body and expanded to dewater and compact the fiber-shaped body.After the fiber-shaped body is compacted, the pressing tool contracts and is removed. The split mold is opened to remove the wet fiber-shaped body. The fiber-shaped body is then pre-dried, coated, and fully dried. Optionally, the container includes a connecting element containing 40 to 90% natural fibers by weight and a binder. The attachment of the connecting element to the fiber-shaped body is not described in detail.

[0007] Similar methods for producing a hollow body from fibrous material in the shape of a bottle using a split mold and an expandable pressing tool are also described in EP 1 081 285 B1 and WO 2003 / 010386 A1. These documents also do not disclose the attachment of a connecting element to the fibrous body.

[0008] A method according to the preamble of claim 1 is known from publication JP 2001-303 500 A. Summary of the invention

[0009] The invention is based on the objective of providing a method and a device that enable the efficient production of a container as described above. In particular, the method should enable a short process time and low energy input, as well as create a reliable connection between the connecting element and the hollow body and enable reliable handling of the hollow body.

[0010] According to the invention, this problem is solved by a method having the features of claim 1 and by a device having the features of claim 12. Advantageous embodiments are described in the dependent claims.

[0011] The process described here for manufacturing a container comprises the following process steps: Providing a split suction mold with a porous wall which, in the closed state, encloses at least one cavity with a suction mold opening; arranging the connecting element on a holder and inserting the holder into the cavity of the suction mold such that the holder protrudes through the suction mold opening and holds the connecting element in the suction mold opening; closing the split suction mold and drawing in fibrous material from a pulp through the wall of the suction mold, so that a hollow body of fibrous material is formed between the holder and the wall; compacting the formed hollow body with the connecting element attached to it; and drying the hollow body. According to the invention, the hollow body is removed from the split suction mold by the holder.

[0012] The split suction mold is assembled from several suction mold parts, in particular from two halves. The hollow fiber mold body is formed when the suction mold is closed, as the suction mold parts are joined and the mold wall encloses a largely closed cavity. The mold wall has a porous, water-permeable inner surface through which pulp can be drawn in. This inner surface can be created conventionally using a suction mold with a largely solid base body made of plastic or metal, into which a sieve element is inserted to form the porous inner wall. However, it is also possible to manufacture the suction mold parts using additive manufacturing techniques, such as 3D printing, whereby fluid channels are formed in the mold material during printing. The pores of the mold parts are connected to a suction device that draws water through the mold wall.The wall of the split suction mold further comprises at least one suction mold opening, which connects the cavity to an environment outside the suction mold. The suction mold opening can be formed in a contact area of ​​at least two suction mold parts and thus have a divisible circumference. Features of the method relating to the formation of the suction mold opening are described below.

[0013] For the method according to the invention, a holder is provided to which a connecting element is attached. The holder is an elongated body that has at least one section with a cross-section that corresponds to the shape of the opening of the container to be manufactured. For example, the cross-section can be round if the opening of the container is to be round. If the opening is rectangular, the cross-section of the holder is rectangular. Likewise, in the case of an oval or other non-circular opening, the cross-section of the holder corresponds to the cross-section of the opening. The cross-section of the holder only needs to correspond to the shape of the opening of the container to be manufactured in the area that corresponds to the opening. The areas of the holder away from the opening of the container to be manufactured can have any different cross-section.The connecting element can be positioned on the holder by means of a feeding device, which places the connecting element in a predetermined position on the holder. For example, the feeding device can position the connecting element on the holder such that it partially or completely surrounds the section of the holder in the area of ​​the opening of the container to be manufactured.

[0014] The holder and the attached connecting element are inserted into the suction mold together. The connecting element is positioned within the suction mold opening, and the holder extends through the opening so that it is partially within the cavity and partially outside the mold. If the suction mold opening is formed in a contact area of ​​at least two mold parts and has a divisible circumference, the holder with the connecting element can be inserted into the open suction mold, and the mold parts can then be closed. If the suction mold opening is not formed in a contact area of ​​at least two mold parts, the holder with the connecting element can be inserted longitudinally through the suction mold opening into the suction mold until the connecting element is positioned within the opening. The suction mold opening can be slightly larger than the connecting element, at least in one section.In this case, the connecting element can be held by the holder in the suction mold opening in such a way that a gap is formed between the connecting element and the suction mold opening.

[0015] After the holder and connecting element have been positioned in the suction mold opening, the split suction mold is closed, and pulp is drawn into the cavity by immersing the suction mold and / or the holder into a pulp-filled basin. The holder can be hollow, allowing the pulp to be drawn through the hollow holder into the suction mold. The pulp contains water and fiber material. The fiber material usually consists of cellulose, such as recycled paper or other recyclable fibers, but also virgin fibers, depending on the requirements for the optical properties of the fiber molded part. The pulp may contain additional additives that positively influence the properties of the fiber molded part.

[0016] The pores in the porous wall of the suction mold are designed such that water penetrates them and the fibrous material is deposited on the wall when the pulp is drawn in. As the suction process continues, the wall thickness of the resulting hollow body increases. In particular, a fibrous layer forms between the wall of the suction mold and the holder, into which the connecting element is embedded. The fibrous layer of the hollow body and the connecting element are positively connected. The connecting element can have a connecting wall with openings that extend approximately parallel to the porous wall. For example, the connecting wall, made of injection-molded thermoplastic, can have a wall thickness on the order of 1 mm and openings with a clear area of, say, 20 mm². If the connecting element surrounds an opening in the container, the connecting wall can extend along the opening in a ring shape and have a width (wall thickness) of approximately...The fibers, which accumulate on the wall, form a layer that penetrates the openings in the connecting wall and thus embeds the connecting wall. The connecting element is thereby firmly anchored in the fiber layer.

[0017] Once a sufficient quantity of fiber material has been deposited in the cavity of the suction mold and / or a predetermined time for fiber material intake has elapsed, the formed hollow body is compacted with the attached connecting element. Compaction means that any water contained within the fiber mold body is mechanically removed. For this purpose, a relative overpressure can be generated in the internal volume of the hollow body, which forces water out of the body's wall. The relative overpressure in the suction mold can be created by applying a vacuum outside the mold components, which is conducted through the porous wall of the mold components to the inner wall, causing the fiber material to be deposited on the porous surface. Compacting the fiber mold body increases its mechanical stability and facilitates its handling.However, even in the suction mold, an expandable pressing tool, described further below, can additionally mechanically press the moisture out of the formed fiber layer.

[0018] The hollow body with the connecting element can be dried by applying heat.

[0019] The container produced in this way can be filled with a flowable product, in particular a cream or a beverage. The opening of the container can then be fitted with a closure that is tightly connected to the connecting element.

[0020] The method described above offers several advantages. The connecting element can be positioned very precisely and quickly in the suction mold opening using the holder. Furthermore, the formation of the fibrous layer of the hollow body around the connecting element results in a particularly strong bond between the connecting element and the hollow body. This is because the pulp has a low viscosity and can therefore penetrate even intricate geometric features (e.g., undercuts or openings in a connecting wall) of the connecting element, where it can dry and harden.

[0021] In practice, the holder can be hollow, allowing the pulp to flow through it into the cavity of the suction mold. This means the entire inner cross-section of the hollow holder is available for the pulp to flow into the suction mold, enabling quick and complete filling of the mold.

[0022] The hollow body is removed from the split suction mold using the holder. The holder simplifies handling the hollow body and transporting it to further processing steps. The hollow body can then be transported by the holder into a transfer mold or a split press mold that is complementary to the hollow body. In other words, the hollow body can be transported by the holder directly from the suction mold into its complementary press mold. Alternatively, the hollow body can be transported from the suction mold into its complementary transfer mold and from there into its complementary press mold. Details of the transfer mold and the press mold are described below. Removing the hollow body from the suction mold and transporting it while it is attached to the holder enables precise and rapid positioning of the hollow body in the transfer mold or press mold. The holder also ensures safe, i.e.,Damage-free removal and transport of the hollow body is possible because the holder can mechanically support it. When the holder and hollow body are moved out of the split suction mold, part of the hollow body rests on the holder. Particularly safe removal and transport are possible if the holder supports the hollow body along essentially its entire length, for example, if the holder extends into the hollow body all the way to its base.

[0023] For the purpose of removing and transporting the hollow body, it is advantageous if the suction mold opening is formed in a contact area of ​​at least two suction mold parts, as described above. The split suction mold can be opened before or after the hollow body has been compacted, and the hollow body is removed from the opened suction mold with the holder.

[0024] Removing and transporting the hollow body on the holder is particularly quick and easy in practice if the holder is pivoted about an axis outside the cavity for transport into the transfer mold or the split press mold. For this purpose, the holder can protrude from the cavity, with one end of the protruding section being pivotally mounted about a pivot axis transverse to the longitudinal direction of the holder. After opening the split suction mold, the holder with the hollow body can be pivoted, for example, 180° from a suction mold section of the split suction mold into a transfer mold or the opened, split press mold. Once the holder has been pivoted and the hollow body is positioned in the transfer mold or press mold, the transfer mold or press mold is moved along the longitudinal direction of the holder, thereby removing the hollow body from the holder.

[0025] In practice, the hollow body can be compacted in the suction mold and / or in the compression mold. Compaction in the suction mold facilitates the removal of the hollow body, which would otherwise be very wet, from the mold. However, this process can result in the pores and structures in the mold wall being imprinted on the surface of the hollow body. Therefore, in addition to or as an alternative to compaction in the suction mold, the hollow body can also be compacted in a specially designed compression mold. For this purpose, the hollow body is transferred from the suction mold to the compression mold.

[0026] The split press mold is formed from multiple press mold components. In the closed state, the press mold has a wall that is essentially complementary to the hollow body and the connecting element. Furthermore, the press mold has a press mold opening that aligns with the opening of the hollow body positioned within the press mold. The wall of the press mold may have no pores or very small pores compared to the pores in the wall of the suction mold. It may also feature decorative structures (grooves or projections) that are pressed into the wall of the container during the pressing process. The wall of the press mold may also include a suction channel that is fluidically connected to the interior of the press mold and through which water can be drained. The hollow body can be inserted into the open press mold and removed after pressing.When the hollow body is arranged in the closed press mold, the mold wall encloses the hollow body, and the internal pressure within the hollow body's volume is increased by a pressing tool, thus compacting the hollow body. Excess water then preferably flows out of the hollow body through the suction channel.

[0027] In practice, the hollow body can be compacted by expanding an expandable pressing tool inserted into the hollow body while it is inside the mold. This process quickly and efficiently dewaters the hollow body and gives it the desired surface structure both on the inside (through the pressing tool) and on the outside (through the inner surface of the mold wall).

[0028] The expandable press tool can, in practice, consist of a bladder or balloon made of an elastomer or other rubber-elastic material and be arranged on a second holder, which can be inserted, in particular, through the mold opening into the inner volume of the hollow body arranged in the mold. The second holder has a fluid line, tightly connected to the press tool and closable, through which a pressurized fluid can be forced into the interior of the press tool. The fluid can be, for example, water, oil, air, industrial gases, or a mixture of the aforementioned fluids.

[0029] To compress the hollow body with the pressing tool in the mold, the second holder is inserted into the inner volume of the hollow body, and the pressing tool is expanded by injecting fluid. The pressing tool expands like a balloon, pressing against the inner surface of the hollow body and pressing it against the wall of the mold. The isostatic fluid pressure results in uniform compression of the hollow body's wall. After a predetermined pressing time or after a predetermined dewatering of the hollow body, the fluid is released from the pressing tool through the fluid line, causing it to contract again, and the pressing tool is withdrawn from the container along with the second holder.

[0030] It is also possible to compact the hollow body using the pressing tool in the suction mold. For this purpose, the first holder can be pulled out through the suction mold opening while the suction mold is closed, and the second holder can be inserted into the hollow body through the suction mold opening. Compaction then takes place in the same way as in a compression mold. Alternatively, the pressing tool can also be positioned on the holder that carries the connecting element.

[0031] In practice, the hollow body can be dried from the inside using radiant heat and / or a hot air stream. For this purpose, a rod-shaped heating device can be inserted through the opening of the hollow body. The heating device can be activated inside the hollow body and emit infrared radiation, UV radiation, and / or microwave radiation. Additionally or alternatively, a hot air stream can exit through the rod-shaped heating device, flowing along the inner surface of the hollow body and exiting through the opening into the surrounding environment. Drying the hollow body removes residual moisture from the fiber material. This allows optional coatings to solidify on the inner surface of the hollow body. Details on applying optional coatings are explained below.

[0032] In practice, the connecting element can be injection-molded from a thermoplastic and, once cured, slid onto the holder. Injection-molded thermoplastic connecting elements can be designed with geometric freedom, meaning with only a few design limitations. For example, such a connecting element can have a grid-like shell section with openings, forming a connecting wall and positioned in the area of ​​the container's opening. The connecting wall has openings that are penetrated by the fibrous material of the hollow body.

[0033] In another practical embodiment of the process, the hollow body can be pre-dried in an oven before compaction. The hollow body can be located in a section of the press mold or transfer mold that is transported through the oven. Alternatively, the hollow body can be placed on a conveyor belt that carries it through the oven. Pre-drying reduces the moisture content of the hollow body before compaction. The oven can be, in particular, a continuous furnace. The reduced residual moisture in the hollow body results in greater dimensional stability during the subsequent compaction step.

[0034] In another practical embodiment, the hollow body can additionally be coated on its inner surface with a biodegradable coating solution. For coating the inner surface, a pipe connected fluidically to a reservoir of the coating solution can be inserted through the opening of the container into the inner volume of the hollow body. The coating solution can then be introduced into the inner volume through the pipe. This creates a coating suitable for contact with food or liquids. If the coating is applied after compaction and before final drying, the coating can be particularly resistant.

[0035] Coating the inner surface is particularly easy in practice if the hollow body is rotated after the coating solution has been poured in, thereby wetting its inner surface. For this purpose, a reservoir of the coating solution can be created inside the hollow body, with excess solution being poured out after the inner surface has been wetted. Rotation can be carried out using a rotating device, which rotates the hollow body around the axis of the container's opening.

[0036] The invention also relates to a device for manufacturing a container according to one of the embodiments of the method described above. The device comprises a basin for a pulp; - a split suction mold with at least one cavity and a porous wall surrounding the cavity; a first holder movable into the split suction mold; a suction device and a feeding device for an annular connecting element to the first holder.

[0037] This device is used in particular to implement the procedure described above.

[0038] In practice, the device may also include at least one of the following features: a transfer mold; an oven; a transfer device; a split press mold; a second holder with an expandable press tool that can be inserted into the split press mold; an injector for a coating solution; a rotary device; a radiant heat source. Brief description of the drawings

[0039] Further practical embodiments and advantages of the invention are described below in connection with the drawings. [ Fig. 1 Figure 1 shows a three-dimensional partial view of a device according to the invention with a plurality of suction cups and holders. Fig. 2 ] shows another three-dimensional partial view of the device made of [ Fig. 1 ] with connecting elements located on the holders. [ Fig. 3 ] shows another three-dimensional partial view of the device made of [ Fig. 1 ] and 2 with holders arranged in the suction cups. [ Fig. 4 ] shows another three-dimensional partial view of the device made of [ Fig. 3 ] with the suction forms in a pulp basin. [ Fig. 5 ] shows another three-dimensional partial view of the device made of [ Fig. 4 ] with hollow bodies and transfer forms on the suction molds. [ Fig. 6 ] shows another three-dimensional partial view of the device made of [ Fig. 5] with the transfer molds and the hollow bodies in a continuous oven. [ Fig. 7 ] shows another three-dimensional partial view of the device made of [ Fig. 6 ], in which the hollow bodies are located in press molds. [ Fig. 8 ] shows an isolated three-dimensional view of a hollow body in a press mold with a press tool. [ Fig. 9 ] shows an isolated three-dimensional view of a hollow body in a press mold with an expanded press tool. [ Fig. 10 ] shows another three-dimensional partial view of the device made of [ Fig. 7 ] with injectors for coating the hollow bodies. [ Fig. 11 ] shows another three-dimensional partial view of the device made of [ Fig. 8 ] with a drying device for the hollow bodies. Description of the embodiments

[0040] The Figures 1 to 9The figures show the process according to the invention and an apparatus for carrying out the process. The figures show an apparatus with which ten containers can be produced simultaneously. It should be noted that the process and apparatus according to the invention are not limited to the simultaneous production of ten containers. Rather, the number of containers produced simultaneously can be adapted to the requirements. The following describes the production process using the example of a single container, which takes place simultaneously in the molds. Figures 1 to 11 Identical components are provided with the same reference numerals.

[0041] To produce a container with a hollow body 1 made of fibrous material and an opening 2, and with a connecting element 3 arranged on the hollow body 1 and surrounding the opening 2, a split suction mold 4 with a porous wall 5 is first provided. The suction mold 4 is rotationally symmetrical and divided along its central longitudinal plane into two suction mold parts 4a, 4b. The suction mold parts 4a, 4b are pivotably connected to each other at a first end about a pivot axis and can be opened along the pivot axis. In the closed state, the suction mold parts 4a, 4b, with their inner wall 5, enclose a cavity 6, which is connected to the environment by means of a suction mold opening 7 in the suction mold 4. The wall 5 has pores (not shown) that fluidly connect the inner wall 5 of the cavity 6 to a suction device (not shown).In an inner region of the suction molded parts 4a, 4b (not shown), the pores are guided to first suction channels 9, through which the pores and the cavity 6 are fluidly connected to a suction device. In the illustrated embodiment, the suction channels 9 are formed by steel pipes which are attached to the suction molded part 4a and support the suction mold 4.

[0042] The suction mold opening 7 is located at an end of the suction mold 4 opposite the first end, in a contact area of ​​the two suction mold parts 4a, 4b. Thus, when the suction mold 4 is opened, the suction mold opening 7 is also opened.

[0043] A first holder 8 is arranged in an area in front of the suction mold opening 7. The first holder 8 has two sections 8a and 8b. The first section 8a is hollow and cylindrical, and the second section 8b, which projects from the first section 8a, is a curved perforated sheet and extends over part of the circumference of the first section 8a. The second section 8b is integrally or at least seamlessly connected to the first section 8a, and both sections 8a and 8b have the same curvature. The first holder 8 is thus an elongated body which is pivotably arranged in a receptacle for the shaft 10 attached to the suction mold 4 by means of a shaft 10 oriented transversely to the longitudinal direction of the first holder 8. The first holder 8 can be made from the [ Fig. 1 ] and 2 position shown outside the suction mold 4 into the position of the [ Fig. 3] is pivoted, in which it extends through the suction mold opening 7 into the interior of the suction mold 4. It then penetrates almost the entire cavity 6 of the suction mold 4.

[0044] The first holder 8 is located in the vertical orientation of the [ Fig. 1 ] in front of the suction mold opening 7 and below a feeding device 11 for feeding an annular connecting element 3 to the first holder 8. The feeding device 11 can, for example, have a tube open at at least one end in which one or more connecting elements 3 are received. The connecting element 3 is formed from an injection-molded and biodegradable thermoplastic in the form of a cured ring. As shown in the Figure 1 and 2As can be seen, the tube with its opening can be moved over the free end of the second section 8b of the first holder 8, thereby sliding a connecting element 3 onto the first holder 8 up to the first section 8a. The cross-sectional shapes of the tube, the first section 8b of the first holder 8, and the suction opening 7 are complementary to each other and may deviate from the circular shape shown in the drawings. They depend in particular on the shape of the opening of the container to be produced.

[0045] After the connecting element 3 is arranged on the first section 8a of the first holder 8, the tube of the feeding device 11 is removed from the first holder 8 and the holder 8 is pivoted about the pivot axis of the shaft 10 into the cavity 6 and the suction mold opening 7, as shown in Figure 3as shown. The suction mold 4 is then closed by folding the suction mold parts 4a and 4b together. The first holder 8 extends through the suction mold opening 7 and, with its first section 8a, holds the connecting element 3 in the suction mold opening 7 in such a way that a gap is formed between the connecting element 3 and the suction mold opening 7.

[0046] The closed suction mold 4, with the first holder 8 contained within it, is immersed in a basin 14 filled with pulp 13. The suction mold 4 is attached to a hollow rotating shaft 15 via the suction channels 9. The interior of the hollow rotating shaft 15 is connected to the suction device, which generates a vacuum and draws out water. This vacuum is directed through the tubular stainless steel suction channels 9 to the wall 5 of the suction mold 4. All suction molds 4 connected to the rotating shaft 15 via the suction channels 9 are moved through the pulp basin 14 when the rotating shaft 15 is turned.

[0047] The pulp 13 is drawn through the hollow cylindrical first section 8a of the holder 8 into the suction mold 4. As the water of the pulp 13 passes through the pores, the fibrous material from the pulp 13 is deposited at the pores and forms a layer along the entire wall 5 of the cavity 6 of the suction mold 4. In this way, a hollow body 1 is formed on the wall 5 of the suction mold 4 from deposited fibers.

[0048] When a sufficient amount of fiber has been deposited on the wall 5 of the suction mold 4, the suction mold 4 is removed from the pulp basin 14, placed in a removal position and opened, as described in Figure 5 shown.

[0049] In the removal position, the formed hollow body 1 is removed from the open suction mold 4 by the first holder 8 and transferred to a transfer mold 17 that is complementary to the hollow body 1. The transfer mold 17 has a shape that is essentially identical to the suction mold part 4b. In particular, the transfer mold 17 also has a recess that is complementary to the first holder 8. For the purpose of transferring the hollow body 1 from the suction mold 4 to the transfer mold 17, the transfer mold 17 is positioned in front of the suction mold opening 7 in a mirror-symmetrical manner to the suction mold part 4b. Subsequently, the first holder 8 is pivoted about the pivot axis of the shaft 10 so that the hollow body 1 and the connecting element 3 come to rest in the transfer mold 17. In the Figure 5In the example shown, the swivel angle is approximately 180°. During swiveling, the hollow body 1 rests against the holder 8, and in particular against its second section 8b. The wet and relatively dimensionally stable hollow body 1 can thus be mechanically stabilized, so that it deforms only slightly despite its low dimensional stability. When the hollow body 1 and the connecting element 3 are located in the transfer mold 17, the first holder 8 is partially inside the transfer mold 17 and partially outside of it. It protrudes through the recess in the transfer mold 17.

[0050] In a next step, the transfer form 17 is moved along the longitudinal axis of the first holder 8 by means of a conveying device 18, as shown in Figure 6 shown. In the Figures 5 to 7The conveying device 18 is designed as a conveyor belt. During the movement of the transfer form 17, the hollow body 1 and the connecting element 3 are pulled away from the first holder 8. The design of the second section 8b as a curved perforated sheet provides good support. The holder 8 can also have a grid-like structure at a distance from the first section 8a, as long as it is ensured that it supports the hollow body 1.

[0051] The conveyor belt 18 is part of a continuous oven 19 known from the prior art, through which the hollow body 1 and the connecting element 3 are moved in the transfer mold 17. The heat generated by the continuous oven 19 causes a reduction in the water content of the hollow body 1 by evaporation. While the hollow body 1 is drying in the continuous oven 19, the rotating shaft 15 with the attached suction mold 4 and the first holder 8 is rotated further and fed back to the beginning of the process to produce another fiber-shaped body.

[0052] After the hollow body 1 and the connecting element have passed through the continuous furnace 19, they are transferred to a split and open press mold 20, in which the hollow body 1 with the connecting element 3 attached to it is further compacted.

[0053] In Figure 7The hollow body 1 and the connecting element 3 are shown arranged in the open press mold 20. The transfer of the hollow body 1 and the connecting element 3 from the transfer mold 17 to the press mold 20 can be carried out with a transfer device 21, which can suction or grip the hollow body 1 and can be moved between the transfer mold 17 after it has passed through the continuous furnace 19 and the position in which the press mold 20 receives the hollow body 1.

[0054] The press mold 20 can have two or more press mold parts 20a, 20b. In the closed state, a wall of the press mold parts 20a, 20b encloses a second cavity, which is essentially complementary to the hollow body 1. The pores in the wall of the press mold 20 are smaller than those in the suction mold 4, so that the compression of the hollow body 1 in the press mold 20 results in a smooth surface of the hollow body 1. The pores in the wall of the press mold are fluidly connected to each other and to a second suction device (not shown) via second suction channels 22. The press mold 20 also has a press mold opening in a contact area of ​​the press mold parts 20a, 20b, which is complementary to the connecting element 3 on the hollow body 1. As intended, the connecting element 3 arranged on the hollow body 1 comes to rest in the press mold opening, so that the opening 2 of the hollow body 1 is aligned with the press mold opening.

[0055] When the hollow body 1 is positioned as intended in a press mold 20a, the press mold 20 is closed. Subsequently, a second holder 23 with a pressing tool 24 attached to it is inserted through the opening 2 in the connecting element 3 into the inner volume of the hollow body 1, as shown in Figure 8The second holder 23 has a fluid line tightly connected to the pressing tool 24. The pressing tool 24 is made of a stretchable elastomer and is tightly connected to the second holder 23 and the fluid line. The pressing tool 24 thus forms an inflatable balloon inside the pressing mold 20. The fluid line carries a pressurized fluid into the pressing tool 24. The fluid line can be connected to a compressed air supply if the supplied fluid is air. Alternatively, a liquid can be supplied to the pressing tool 24 from a compressor or pump. Using a liquid, the pressing tool 24 can generate a higher pressure inside the pressing mold 20. Figure 9 shows the press tool 24 in its expanded form.

[0056] Due to the isostatic pressure of the fluid in the press tool 24 and the elasticity of the press tool 24, the hollow body 1 is pressed uniformly against the wall of the press mold 20 and is thereby compacted, dewatered, and hardened. This also strengthens the connection between the wall of the hollow body 1 and the connecting element 3. At the same time, the surface of the wall is imprinted onto the hollow body 1.

[0057] The water escaping from the hollow body 1 during compression is extracted via the pores in the wall of the press mold 20 and the second extraction channels 22. After a predetermined time or when a predefined quantity of water has been removed from the hollow body 1, the fluid is drained from the press tool 24, causing the elastic press tool 24 to contract and return to its original, in Figure 8The press tool 24 assumes the shape shown. The press tool 24 can then be removed from the hollow body 1 together with the second holder 23 through the opening 2, and the press mold 20 is opened.

[0058] Subsequently, the hollow body 1 and the connecting element 3 are removed from the press mold 20 by means of the previously mentioned transfer device 21 and placed in a Figure 10 The coating station shown is used. The coating station includes an injector 25, which can be inserted through opening 2, for filling the inner volume of the hollow body 1 with a coating solution. The coating solution can be, in particular, biodegradable and / or food-safe. The hollow body 1 is filled with a predetermined quantity of the coating solution by means of the injector 25. The hollow body 1 is oriented in such a way that the coating solution cannot flow out of the inner volume.

[0059] When the hollow body 1 is filled with the predetermined amount of coating solution, the hollow body is rotated by a rotating device 26 about an axis coaxial with the opening 2. Figure 10 The rotation device 26 is designed as an inclined plane along which the hollow body 1 rolls. If the hollow body 1 is not itself rotationally symmetrical, it can be inserted into a hollow cylinder that can roll along the inclined plane. The rotation wets the entire inner surface of the hollow body 1 with the coating solution. Excess coating solution is then poured off. For this purpose, the hollow body 1 can be picked up by the transfer device 21 and oriented with the opening 2 facing downwards.

[0060] As an alternative to rotating the hollow body 1 by rolling it along an inclined plane, the hollow body 1 can also be gripped by a gripping device in a horizontal orientation of its longitudinal axis and the gripping device can be rotated.

[0061] In this orientation, the coated hollow body 1 is transferred from the transfer device 21 to a Figure 11 The drying station shown is transferred. The drying station has a rod-shaped heating device 27 onto which the hollow body 1 is pushed through the opening 2. Infrared radiation is activated in the hollow body 1, which cures the coating solution and dries the hollow body 1 completely. The heating device 27 is thus designed as a radiant heat source.

[0062] The process is completed when the hollow body 1 is fully dried and transferred from the drying station to a storage area.

[0063] The invention is not limited to the described embodiments. It can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. List of reference symbols

[0064] 1 Hollow body 2 Opening 3 Connection element 4 Suction mold 4a, 4b Suction mold parts 5 Wall of the suction mold 6 Cavity 7 First mold opening 8 First holder 9 First suction channels 10 Shaft 11 Feeding device 13 Pulp 14 Basin 15 Rotary shaft 17 Transfer mold 18 Conveyor, conveyor belt 19 Continuous oven 20 Press mold 20a, 20b Press mold parts 21 Transfer device 22 Second suction channels 23 Second holder 24 Press tool 25 Injector 26 Rotary device, inclined plane 27 Radiant heat source, rod-shaped heating device

Claims

1. Method for producing a receptacle with a hollow body (1) of fiber material and having an opening (2) and with a connection element (3) arranged on the hollow body and surrounding the opening (2), the method comprising the following method steps: - providing a split suction mold (4) with a porous wall (5) which, in the closed state, encloses at least one cavity (6) with a mold opening (7); - arranging the connection element (3) on a holding device (8) and insertion of the holding device (8) into the cavity (6) of the suction mold (4) in such a way that the holding device (8) protrudes through the mold opening (7) and holds the connection element (3) in the mold opening (7); - closing the split suction mold (4) and sucking fiber material from a pulp (13) through the wall (5) of the suction mold (4), so that the hollow body (1) is formed between the holding device (8) and the wall (5); - compacting the formed hollow body (1) with the connection element (3) arranged thereon; and - drying the hollow body (1); characterized in that the hollow body (1) on the holding device (8) is removed from the split suction mold (4).

2. Method according to claim 1, characterized in that the holding device (8) is hollow and the pulp (13) flows through the holding device (8) into the cavity (6) of the suction mold (4).

3. Method according to claim 1 or 2, characterized in that the hollow body (1) is transported on the holding device (8) into a transfer mold (17) complementary to the hollow body (1) or a split press mold (20).

4. Method according to one of the preceding claims, characterized in that the holding device (8) for removing the hollow body (1) from the split suction mold (4) is pivoted about a section of the holding device (8) protruding out of the cavity (6).

5. Method according to one of the preceding claims, characterized in that the hollow body (1) is compacted in the suction mold (4) and / or the press mold (20).

6. Method according to claim 5, characterized in that the hollow body (1) is compacted by expanding an expandable pressing tool (24) inserted into the hollow body (1).

7. Method according to one of the preceding claims, characterized in that the hollow body (1) is dried from the inside by means of radiant heat and / or a stream of hot air.

8. Method according to one of the preceding claims, characterized in that the connection element (3) is injection-molded, cured and pushed onto the holding device (8).

9. Method according to one of the preceding claims, characterized in that the hollow body (1) is pre-dried in an oven (19) before compaction.

10. Method according to one of the preceding claims, characterized in that the hollow body (1) is coated on its inner surface with a biodegradable coating solution.

11. Method according to claim 10, characterized in that the coating of the inner surface is carried out by filling the coating solution into the hollow body (1), wetting the inner surface by rotating the hollow body (1) and pouring out excess coating solution.

12. Device for producing a receptacle according to a method according to any one of the preceding claims, comprising - a basin (14) for a pulp (13); - a split suction mold (4) with at least one cavity (6) and a porous wall (5) surrounding the cavity (6); - a first holding device (8) movable into the split suction mold (4); - a suction device and - a feeding device (11) for a ring-shaped connection element (3) to the first holding device (8).

13. Device according to claim 12, characterized in that it comprises at least one of the following features: - a transfer mold (17); - an oven (19); - a transfer device (21); - a split press mold (20); - a second holding device (23) having an expandable pressing tool (24) and being insertable into the split press mold (20); - a compressor; - an injector (25) for a coating solution; - a rotation device (26); - a radiant heat source (27).

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