DE102021103400A1 - Method of manufacturing a fibrous material container and fibrous material container - Google Patents

Abstract

The invention relates to a method for producing a container comprising a shell and a lid, which comprises the following steps: (a) providing a first flat material consisting of fiber material; (b) forming the first sheet of material into a shell using a deep drawing process in a forming apparatus and forming side walls of the shell; and (c) closing the tray by attaching a lid of a second sheet material. The first flat material (10) is provided in particular by injection molding the fiber material in an injection molding station (30). The invention also relates to a container that can be produced using the method according to the invention, in particular a packaging for one or more tooth-cleaning devices.

Description

The invention relates to a method for producing a container made of fiber material and a container produced according to this method, in particular a packaging for a toothbrush or an interdental cleaning device.

STATE OF THE ART

Packaging for consumer items, for example food or hygiene items such as toothbrushes or the like, usually has to be produced in large quantities and as cost-effectively as possible. Conventional packaging consists, for example, of a tray that is closed by sticking a film on it. The shell is usually made of plastic. Such packaging is in EP 3 611 108 A1 disclosed.

Such a shell is usually produced by thermal forming (thermoforming) of a plastic film. A flat blank of a plastic film is plasticized by heating and formed into a shell by means of a deep-drawing die and, if necessary, additionally with compressed air or by applying a vacuum. Similar to the deep-drawing of sheet metal, this process is often also referred to as deep-drawing. Such a procedure is, for example, in EP 0 536 517 A1 and WO 2016/095892 A1 disclosed.

The thickness of the film in the area of the side walls of the shell is reduced as a result of the thermal stress and the deformation of the plastic film during forming. In order to compensate for the reduction in film thickness and to ensure the wall thickness required for dimensional stability, a film with a particularly large thickness is therefore often used as the starting material. This has the disadvantage that more material has to be used than is actually necessary, since in this way the wall thickness in the area of the bottom of the shell turns out to be greater than actually necessary. To solve this problem, the EP 0 536 517 A1 suggest that the amount of material required can be reduced by using a plastic with closed pores.

Another disadvantage of conventional manufacturing processes is that the plastic film has to be cut to the required size after forming. This often results in excess cutting that cannot be reused and thus unnecessarily increases material consumption.

Another disadvantage of the known methods is the use of plastic as the packaging material. Plastic is largely made from fossil raw materials and its production thus contributes to the emission of carbon dioxide. In addition, very few plastics are biodegradable, so that the disposal of plastic products leads to significant environmental pollution.

DESCRIPTION OF THE INVENTION

The object of the present invention is to provide a method for producing a container which consists predominantly of renewable, easily recyclable and environmentally friendly raw materials. The manufacturing process should be able to be carried out inexpensively. In particular, the method should be distinguished by the economical use of materials. In addition, the method should be suitable for the production of thin-walled and at the same time dimensionally stable containers, in particular packaging for consumer goods.

These objects are achieved by the method for manufacturing a container and the container according to the present invention.

1. (a) Bereitstellen eines ersten flächigen Materials bestehend aus Fasermaterial;
2. (b) Umformen des ersten flächigen Materials zu einer Schale unter Einsatz eines Tiefziehverfahrens in einer Umformvorrichtung und unter Ausbildung von Seitenwänden der Schale;
3. (c) Verschließen der Schale durch Befestigen eines Deckels aus einem zweiten flächigen Material.

The invention relates to a method for producing a container comprising a shell and a lid, which comprises the following steps:

1. (a) providing a first sheet material consisting of fiber material;
2. (b) forming the first sheet of material into a shell using a deep drawing process in a forming apparatus and forming side walls of the shell;
3. (c) closing the tray by attaching a lid of a second sheet material.

The invention also relates to a container that can be produced using the method according to the invention.

An essential element of the invention is the production of the shell by reshaping a fiber material. Fiber material consists of renewable raw materials, such as wood fiber, and is therefore easily compostable or recyclable. By making the tray from this eco-friendly material, the amount of less eco-friendly plastic used can be significantly reduced compared to traditional containers.

A further advantage of the invention is that the tray produced by deep-drawing the fibrous material has no folded edges, unlike conventional folded cardboard packaging or has side openings. In addition, the time-consuming folding of a cardboard blank is no longer necessary.

Individual features of the invention are explained in more detail below.

The container that can be produced by the method has a shell made of fiber material and a lid attached thereto. The container is particularly suitable as packaging for consumer goods. The lid can completely or partially close the container. The container is preferably completely closed, so that the goods in the container are shielded from external influences. The container is therefore particularly suitable as packaging for foodstuffs or hygiene articles. Preferably, the container is the packaging of one or more dental cleaning implements, such as a toothbrush or dental floss holder.

The shell of the container is characterized by having a bottom, side walls and an opening. The opening is usually on the opposite side of the tray from the bottom. The opening is preferably bounded by a flange which encloses all or part of the opening and is at an angle to the side walls. This flange is used for better attachment of the cover. The base of the shell can have, for example, a rectangular, oval, kidney-shaped or round base.

The shell is formed by reshaping a first sheet of material made of fibrous material. In the context of this invention, a fiber material obtained from vegetable raw materials is referred to as fiber material. The fibrous material preferably contains cellulose and preferably comprises wood pulp, semi-chemical pulp or chemical pulp. Mechanical pulp is produced by defibration of plant material, particularly wood, and includes lignocellulose. In semi-pulp, the lignin content is reduced compared to wood pulp. In pulp, the lignin content is almost completely reduced by chemical pulping processes. The fiber material can be obtained, for example, from wood, in particular softwood or hardwood, straw, hemp, cotton, flax, bamboo, bagasse and/or kenaf. The fiber material can preferably also include waste paper. In a preferred embodiment, the fiber material consists of waste paper. Furthermore, the fiber material can include rags, ie vegetable fibers that are obtained from textile waste, for example from cotton or linen.

The fiber material preferably does not include any synthetic fibers.

The fiber material preferably consists entirely of vegetable raw materials. The fiber material preferably consists of fully compostable components.

The fiber material can also contain fillers and/or binders. Chalk is preferably used as a filler. Polylactides are preferably used as binders, in particular polylactides obtained from corn starch. The admixture of polylactide to the fiber material favors the forming. The proportion of polylactide, based on the total weight of the fiber material, is preferably 1 to 50% by weight, preferably 2 to 30% by weight, particularly preferably 5 to 15% by weight.

The forming of the first flat material takes place in a forming device. This preferably has a movable deep-drawing punch and a deep-drawing die. For forming, the first flat material is first placed on the deep-drawing die and then pressed into the cavity of the die by the punch, thereby forming a shell. Preferably, the forming device also has one or more spring-loaded hold-down devices, so that the first flat material can be clamped between the deep-drawing die and the hold-down device. This prevents or controls the first flat material from slipping down into the recess of the deep-drawing die.

In a preferred embodiment, the first flat material is heated before and/or during the forming. For this purpose, the forming device preferably comprises a heating device for heating the first flat material to be formed.

In a preferred embodiment, the first flat material is moistened before and/or during the forming. The first flat material can be moistened on one or both sides. The first flat material is preferably moistened on both sides. For this purpose, the forming device preferably includes a moistening device.

It is particularly advantageous for the forming process if the first flat material is both heated and moistened before and/or during the forming.

For example, a foil or cardboard consisting of the fiber material can be used as the first flat material. The sheet material can be rigid or flexible.

The thickness of the material can be the same over the entire surface or can vary. In a preferred embodiment, however, the flat material has thickenings at those points that are particularly severely deformed during forming. This allows the reduction in wall thickness of the material that occurs during forming to be compensated. The thickenings are preferably arranged in the area of the flat material that forms the side walls of the shell during reshaping, since the strongest deformation and thus also the greatest reduction in wall thickness occurs in this area.

In one embodiment, the sheet material is obtained by extruding granulated fibrous material into a web. The web is then cut to the desired size, if necessary. The size of the cut depends on the desired size of the bowl. An advantage of this method is that the width of the web can be adjusted in the extrusion process, for example by suitably dimensioning the extrusion nozzle. The width of the web is preferably selected such that it corresponds to the width of the blank required for the reshaping, or to an integer multiple thereof. In this way it is possible to reduce to a minimum the amount of excess fibrous material produced during cutting, since the web either does not have to be cut widthwise at all or can be cut into precisely fitting pieces.

A particularly preferred embodiment of the method provides that the first flat material is produced by injection molding of the fiber material. In this way, the first flat material is provided as a flat molded part, from which the shell is formed during the subsequent forming. The particular advantage of this process is that the size and geometry of the flat molded part can be precisely adapted to the requirements of the forming process. This means that the flat molded part no longer has to be cut to size and there is no excess waste product. In this way, the amount of fiber material used is optimally utilized. Furthermore, fiber material whose composition is not suitable for producing a film by a conventional extrusion process can also be processed by injection molding.

The injection molding takes place in an injection molding station. This includes an injection mold, which usually has a movable mold. By means of the movable mold, the injection mold can be closed for the injection molding process and opened to remove the flat molded part.

The fibrous material is preferably provided in the form of granules for the injection molding process, which, in conjunction with the supply of heat, is metered into a mouldable, homogeneous mass and then injected into the closed injection mold.

The injection molding is carried out, for example, by spot gating, preferably perpendicular to the plane of the flat molded part, or by surface gating, preferably parallel to the plane of the flat molded part. When using pin gating, a visible injection point remains on the molded part, which also remains recognizable on the shell. The gating surface on the shell can also be seen in surface gating, but if surface gating takes place parallel to the plane of the molded part, the gating surface is in an edge area of the shell and is therefore less visible. For this reason, surface gating is preferable in order to achieve a uniform shell appearance.

In a particularly preferred embodiment, injection molding of the fiber material is used in order to produce thickenings in the flat shaped part at those points that are particularly severely deformed during forming. As described above, the reduction in the wall thickness of the material that occurs during forming can be compensated for in this way. The particular advantage of injection molding lies in the fact that the shape and position of the thickenings can be set with great accuracy by suitably designing the injection mold. In this way, injection molding contributes to further material savings.

In a preferred embodiment, the reshaping of the first flat material by deep-drawing and the provision of the first flat material by injection molding proceed synchronously. This means that exactly one forming step is carried out per injection molding cycle.

In a particularly preferred embodiment, the injection molding station has a movable mold for closing the injection mold, with the movement of the mold being coupled to the movement of the deep-drawing punch of the forming device. The movable forming tool and the deep-drawing punch are preferably mechanically coupled to one another, so that both are moved at the same time. Preferably, the movable forming tool and the deep-drawing punch are driven by the same motor. This enables injection molding and forming to be carried out synchronously.

A transfer device is preferably provided, which removes the first flat material from the injection molding station and transfers it to the forming device.

The method also includes closing the tray by attaching a lid of a second sheet material. The second flat material can consist of plastic or a fiber material, for example. The second sheet material preferably consists of the fiber material described above. The cover can in particular have the form of a film or a card. For example, although the second sheet of material is substantially planar, it may have a peripheral edge that extends from the planar surface for attachment to the shell. In this way, the lid can close the shell in the manner of a clamping lid. A lid secured in this manner is releasably secured to the tray so that the tray can be easily opened and reclosed. In an alternative embodiment, the lid is glued to the tray. The adhesive connection can be designed in such a way that it is irreversibly destroyed when the lid is opened, so that the shell cannot be closed again. In the case of a lid attached by gluing, the tray is filled with the item to be packaged before the lid is attached to the tray.

The production of the shell and the attachment of the lid can take place with more or less great time and space distance from each other. For example, the shell can first be produced at a first location, then transported to a second location and filled with the goods to be packaged, and finally closed at a third location by fastening the lid.

• 1 Schematische Darstellung des ersten flächigen Materials und der Umformvorrichtung vor dem Umformen;
• 2 schematische Darstellung des ersten flächigen Materials und der Umformvorrichtung während des Umformens;
• 3 A Draufsicht auf ein durch Spritzgießen hergestelltes erstes flächige Material gemäß einer Ausführungsform der Erfindung;
• 3 B Querschnittsansicht eines durch Spritzgießen hergestellten ersten flächigen Materials gemäß einer Ausführungsform der Erfindung;
• 4 A Draufsicht auf ein durch Spritzgießen hergestelltes erstes flächige Material gemäß einer weiteren Ausführungsform der Erfindung;
• 4 B Querschnittsansicht eines durch Spritzgießen hergestellten ersten flächigen Materials gemäß einer weiteren Ausführungsform der Erfindung und
• 5 schematische Darstellung einer Spritzgießstation.

Further embodiments are shown in the following drawings for a better understanding of the invention. These show:

• 1 Schematic representation of the first flat material and the forming device before forming;
• 2 schematic representation of the first flat material and the forming device during forming;
• 3 A Top view of an injection molded first sheet material according to an embodiment of the invention;
• 3 B Cross-sectional view of a first sheet material made by injection molding according to an embodiment of the invention;
• 4 A Plan view of a first sheet material produced by injection molding according to a further embodiment of the invention;
• 4 B Cross-sectional view of a first sheet material produced by injection molding according to a further embodiment of the invention and
• 5 schematic representation of an injection molding station.

the 1 and 2 show schematic representations of the first flat material 10 and the forming device 20. 1 12 shows the first flat material 10 before the beginning of the forming. The first flat material 10 rests on the deep-drawing die 21 and is clamped by the hold-down devices 22 . A movable deep-drawing punch 23 then presses the first flat material 10 into the recess of the deep-drawing die 21, the first flat material 10 being formed into a shell ( 2 ).

The shell has a bottom 12, side walls 13 and a flange 14. During the forming, the side walls 13 are formed from the thickenings 11 of the first flat material 10 . In this way, a reduction in the wall thickness during forming is compensated for, so that the shell has essentially the same wall thickness in the area of the side walls 13 as in the area of the base 12.

After the forming, the deep-drawing punch 23 is moved upwards again out of the depression in the deep-drawing die 21 . The hold-down devices 22 are then released in order to remove the shell from the forming device 20 .

the 3A and 3B show schematic representations of a first sheet material 10 produced by injection molding. 3A shows a plan view of the first flat material 10, 3B shows a cross-sectional view. The first flat material 10 has a circumferential thickening 11 which is arranged in the area which will later be formed into the side walls of the shell. The first flat material 10 shown in this embodiment is produced by spot gating at the injection points 15 perpendicular to the plane of the first flat material.

the 4A and 4B show another embodiment of a first sheet material 10 produced by injection molding. In this embodiment, too, the first sheet material 10 has a circumferential thickening 11 which, at the later ren forming forms the side walls of the shell. In contrast to the embodiment according to the 3A becomes the embodiment in 4A produced parallel to the plane of the first flat material 10 by surface gating. The sprue channel 34 is shown schematically and opens into the two injection points 16 at the edge of the first flat material 10.

the 5 shows a schematic representation of an injection molding station 30 for the production of a first flat material. The injection molding station 30 comprises a movable mold tool 32 and a stationary mold half 31. The movable mold tool 32 and the mold half 31 together form a mold cavity 35 in which the first sheet material 10 can be produced. The mold cavity 35 has bulges 36 for producing a circumferential thickening on the first flat material. A sprue channel 33 for injecting the fiber material is provided in the mold half 31 . The sprue channel 33 opens out perpendicularly to the plane of the first flat material and is designed here in the form of a nozzle for spot gating. In an alternative embodiment not illustrated here, the sprue channel 33 can also be formed in the movable mold 32 .

Reference List

10

First flat material

11

thickening

12

floor

13

side walls

14

flange

15

Injection points for pin gating

16

Injection points for surface gating

20

forming device

21

deep-drawing die

22

hold-down

23

deep-drawing stamp

30

injection molding station

31

mold half

32

moving mold

33

runner

34

runner

35

mold nest

36

bulges

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 3611108 A1 [0002]
• EP 0536517 A1 [0003, 0004]
• WO 2016/095892 A1 [0003]

Claims (13)

Method for manufacturing a container comprising a shell and a lid, comprising the steps: (a) providing a first sheet material (10) consisting of fiber material; (b) forming the first sheet material (10) into a shell using a deep-drawing process in a forming device (20) and forming side walls (13) of the shell; (c) closing the tray by attaching a lid of a second sheet material. procedure after claim 1 , characterized in that the first flat material (10) has thickenings (11) in the areas which form the side walls (13) of the shell during forming. Procedure according to one of Claims 1 or 2 , characterized in that the first sheet material (10) is provided by injection molding the fiber material in an injection molding station (30). procedure after claim 3 , characterized in that the injection molding is carried out by point gating or by surface gating. Procedure according to one of claims 2 until 4 , characterized in that the forming device (20) has a movable deep-drawing stamp (23) for forming the first flat material (10) and the injection molding station (20) has a movable mold (32) for closing the injection molding station (20), the movement of the Deep-drawing stamp (23) is coupled to the movement of the mold (32). Method according to one of the preceding claims, characterized in that the forming device (20) has a deep-drawing die (21) and one or more spring-loaded hold-down devices (22) and the first flat material (10) is clamped between the deep-drawing die (21) and hold-down device (22). can be. Method according to one of the preceding claims, characterized in that the fibrous material comprises mechanical pulp, semi-chemical pulp or chemical pulp. Method according to one of the preceding claims, characterized in that the fiber material comprises polylactide. Method according to one of the preceding claims, characterized in that the first flat material (10) is heated and/or moistened during the forming. Method according to any one of the preceding claims, characterized in that the tray has a flange (14) at its opening for fastening the lid. Method according to one of the preceding claims, characterized in that the second flat material consists of fiber material. Container comprising a shell and a lid, characterized in that the shell consists of a fibrous material producible by the method according to any one of the preceding claims. container after claim 12 , characterized in that the container is packaging for one or more dental cleaning devices, in particular for toothbrushes or dental floss holders.

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