Method for producing a preform and a packaging, forming device, and preform

Abstract

The invention relates to a method for producing a preform (2, 28) from a nonwoven material (3) in the form of a sheet by deep drawing, using a die (11) and a drawing punch (12) that can be inserted into the die (11) in a drawing direction, wherein the die (11) has a die portion (39) having an inner contour which extends parallel to the drawing direction (Z) and is curved in a plane perpendicular to the drawing direction (Z), and wherein the drawing punch (12) has a forming portion (43) having an outer contour which is partly curved in a plane perpendicular to the drawing direction (Z), corresponding to the die portion (39), and which tapers at least counter to the drawing direction (Z), preferably continuously, in which method: the nonwoven material (3) is positioned between a die (11) and a drawing punch (12), and then the drawing punch (12) is inserted into the die portion (39) in the drawing direction (Z); during the insertion of the drawing punch (12) into the die portion (39), the nonwoven material (3) is deep-drawn at least in some sections in a drawing gap (42) between the die portion (39) and a drawing portion (40) of the drawing punch (12); and, during the insertion of the drawing punch (12) into the die portion (39), a preform is formed between the die portion (39) and the forming portion (43), the preform having a curved wall portion (25, 32) in a plane perpendicular to the drawing direction (Z), and a wall thickness (d2, d4) that increases counter to the drawing direction (Z), preferably continuously, in said curved wall portion (25, 32).

Description

[0001] Method for producing a preform and a packaging, forming device and preform

[0002] The invention relates to a method for producing a preform for further processing into a packaging made from a flat nonwoven fiber material by deep drawing, and to a method for producing a stackable packaging from a preform formed from a nonwoven fiber material. Furthermore, the invention relates to a forming device for producing a preform from a flat nonwoven fiber material by deep drawing, comprising a die and a drawing punch that can be inserted into the die in a drawing direction, and to a preform made from a nonwoven fiber material for further processing into a packaging with an opening, a side wall, and a base region, wherein the side wall has at least one wall section curved about a central longitudinal axis of the preform.

[0003] Plastic packaging can be manufactured in a wide variety of shapes depending on the application. Thermoforming machines are often used to transform a flat plastic into a three-dimensional package. However, such plastic packaging enters the environment in large quantities, where it is generally not biodegradable and is thus mechanically shredded into unwanted microplastics over time. To prevent this, increased effort is required for the return and recycling of plastic packaging.

[0004] Against this backdrop, packaging made from biodegradable, particularly renewable, fibers such as paper or cardboard is increasingly being used. These can be coated if necessary to provide sufficient moisture resistance and suitability for food packaging. However, such packaging is complex to manufacture and can only be produced in a limited number of shapes, as the fiber materials are less malleable than thermoplastics, in particular. This applies particularly to packaging made from a nonwoven material, such as a nonwoven made from cellulose fibers, which is therefore particularly environmentally friendly.

[0005] To produce packaging from a flat nonwoven material with a conical shape that allows multiple packages to be stacked inside each other, it has been proposed to first produce a so-called preform in a forming device by deep-drawing the nonwoven material, which resembles the shape of the desired package, and then to press this preform into its final shape to produce the package. This is done in a single operation using a correspondingly shaped drawing and pressing die and a corresponding die.

[0006] The packaging has a base area, an opening and a side wall provided between the base area and the opening. Since side walls with edges or corners break easily, the side walls have at least one wall section curved around a central longitudinal axis of the preform. The curvature can have a constant radius arranged in a plane around a central longitudinal axis of the preform. In a particularly simple form of packaging, namely a cup with a circular base area, the radius is constant all the way around the central longitudinal axis of the preform. However, preforms with an oval base area and preforms with a base area that has a straight edge in sections are also conceivable, from which packaging with an almost rectangular base with rounded edges can be produced.

[0007] However, the known process can only reliably produce packaging that is relatively flat relative to its size. Such packaging therefore does not meet all requirements, which is why there is a need for packaging that has a greater depth, particularly in terms of the base area, and that allows for very different base shapes.

[0008] Therefore, the object of the present invention is to design and further develop the method, the forming device and the preform of the type mentioned at the outset and explained in more detail above in such a way that greater flexibility in the shaping of the packaging can be achieved.

[0009] This object is achieved according to claim 1 by a method for producing a preform for further processing into a packaging from a flat nonwoven material by deep drawing, with a die and a drawing punch which can be moved into the die in a drawing direction, wherein the die has a die section with an inner contour which extends at least substantially parallel to the drawing direction and is curved at least in sections in a plane perpendicular to the drawing direction, and wherein the drawing punch has a forming section with an outer contour which is curved at least in sections and corresponding to the die section in a plane perpendicular to the drawing direction and at least in sections opposite to the drawing direction, preferably continuously,

[0010] - in which the nonwoven material is arranged between a die and a drawing punch and the drawing punch is then moved into the die section in the drawing direction,

[0011] - in which, during the insertion of the drawing punch into the die section, the nonwoven material is deep-drawn at least in sections in a drawing gap between the die section and a drawing section of the drawing punch,

[0012] - in which, during the insertion of the drawing punch into the die section, a preform is formed between the die section and the mold section, having at least one curved wall section in a plane perpendicular to the drawing direction and having a wall thickness that increases, preferably continuously, in the at least one curved wall section counter to the drawing direction. The stated object is further achieved according to claim 7 by a method for producing a stackable package from a preform formed from a nonwoven material,

[0013] - in which the preform is formed according to one of claims 1 to 6,

[0014] - in which the preform is introduced into a mold of a press with a conical inner contour and is pressed in the mold with a conical press die while reducing the wall thickness of the preform, at least in at least one curved wall section, and

[0015] - in which, preferably, successively compressed packages are stacked one inside the other.

[0016] The above-mentioned object is also achieved in a forming device according to the preamble of claim 9 in that the die has a die section with an inner contour extending at least substantially parallel to the drawing direction and at least partially curved in a plane perpendicular to the drawing direction, and in that the drawing punch has a forming section with an outer contour that is curved at least partially and correspondingly to the die section in a plane parallel to the drawing direction and at least partially tapering counter to the drawing direction, preferably continuously.

[0017] The aforementioned object is also achieved in a preform according to the preamble of claim 12 in that the nonwoven fiber material in the at least one curved wall section is increasingly folded in the circumferential direction around the central longitudinal axis of the preform from the base region towards the opening of the preform, and in that the wall thickness of the at least one curved wall section increases from the base region towards the opening of the preform, preferably corresponding to the folding of the nonwoven fiber material or at least substantially continuously. The nonwoven fiber material can preferably be one that is produced using the so-called airlaid process. In this process, the fibers are laid on top of one another by means of an air stream to form a nonwoven web. The nonwoven web forms a loose nonwoven fabric that is made durable by means of pressure or binding agents.By pressure, we mean simply a certain degree of compaction so that the resulting nonwoven material is still sufficiently malleable for deep drawing. Suitable fiber materials include, in particular, cellulose, lignocellulose obtained from lignin-containing wood materials, or other predominantly organic fibers, such as flax or hemp. The fibers do not have to be organic, but renewable materials are generally preferred for ecological reasons. The use of synthetic fibers, such as plastic, is also conceivable; these fibers can also be used together with inorganic or renewable fibers. By adding additives such as alkyl ketene dimers (AKD), which can make cellulose fibers hydrophobic, the resulting packaging can, for example, be made more moisture-resistant.

[0018] The nonwoven material to be deep-drawn preferably has a density between 10 kg / m 3and 200 kg / m 3 Particularly preferred are nonwoven materials with a density between 20 kg / m 3 and 350 kg / m 3 The thickness of the fiber materials can preferably be between 1 mm and 20 mm, in particular between 2.5 mm and 6 mm. These fiber nonwoven materials are therefore so lightly compressed that they cannot absorb any significant tensile forces without tearing. This circumstance is taken into account by the process for producing a preform. The fiber nonwoven material of the preform is also not yet so highly compressed that the preform could be used as packaging in the desired manner. During deep drawing, the preform is subjected to a surface pressure as constant as possible, preferably between 6 N / mm 2 and 22 N / mm 2 , especially between 10 N / mm 2and 15 N / mm. A constant or homogeneous surface pressure results in a constant or homogeneous material density of the preform, especially with a homogeneous nonwoven material. To improve stability, the preform is then pressed into the finished packaging or into a mold, with a surface pressure of between 15 N / mm 2 and 250 N / mm 2 In this case, a constant or homogeneous surface pressure results in a constant or homogeneous material density of the mold, especially in the case of a preform with a constant or homogeneous material density.

[0019] The deep drawing of the nonwoven material takes place between a die and a drawing punch, wherein the drawing punch can be moved into the die in a drawing direction to effect the deep drawing of the nonwoven material. The die has a die section against which the preform rests during deep drawing and which extends at least substantially parallel to the drawing direction. In a plane perpendicular to the drawing direction, the die section has a curved inner contour at least in sections. The curved inner contour preferably extends over the entire longitudinal extent of the at least one curved inner contour of the die section parallel to the drawing direction. The curved inner contour can extend with a constant radius or a varying radius circumferentially around the drawing direction, for example in an oval shape. However, this does not have to be the case.The inner contour can also have at least one straight section in order to form a straight wall section of the preform.

[0020] The drawing punch has a forming section which is at least fundamentally designed to correspond to the die section. The forming section also has an outer contour which is curved at least in sections in a plane perpendicular to the drawing direction and corresponding to the die section. In addition, however, unlike the inner contour of the die section, the outer contour is tapered at least in sections in a direction opposite to the drawing direction, thus in the region of the at least one curved outer contour. This taper is also preferably continuous, in particular with a constant gradient, counter to the drawing direction. Furthermore, the outer contour is tapered counter to the drawing direction, at least in the region of the at least one curved outer contour.In other areas of the outer contour, especially in non-curved areas of the outer contour, a tapered design of the drawing punch can be dispensed with.

[0021] To deep-draw the nonwoven material, it is placed between a die and a drawing punch, and the drawing punch is then moved into the die section of the die in the drawing direction. As the drawing punch moves into the die section, the nonwoven material is deep-drawn, at least in sections, in a drawing gap between the die section and a drawing section of the drawing punch. The drawing gap preferably forms between the free end of the drawing punch and the die section. The drawing gap causes the nonwoven material to be drawn into the die section of the die.The nonwoven material enters the gap between the die section and the forming section of the drawing punch, thereby producing a preform having at least one curved wall section between the die section and the forming section, specifically in a plane perpendicular to the drawing direction and corresponding to and adjacent to the curved inner contour of the die section and the curved outer contour of the forming section of the drawing punch. Corresponding to the tapered shape of the forming section, at least in this wall section, the at least one curved wall section is formed with a wall thickness that increases, preferably continuously, counter to the drawing direction. The preform preferably fills the gap between the die section and the forming section, preferably not only in the at least one curved wall section, unless the preform is formed with a circumferentially curved wall section.

[0022] During the deep drawing of the nonwoven material, as the drawing punch is increasingly inserted into the die between the at least one curved inner contour of the die section and the at least one curved outer contour of the mold section, more and more nonwoven material is drawn into the die section. The material is only partially compacted, so that a larger volume of nonwoven material accumulates in the corresponding curved wall section of the preform with increasing distance from the preform base. Therefore, the wall thickness of the preform in this area increases with increasing distance from the preform base.

[0023] For example, if a preform is formed with a circular base and a wall section that is uniformly curved all the way around the drawing direction, rings of nonwoven material with a constant width and an (originally) larger diameter are gradually drawn into the die section with a constant diameter. Initially, the circumference of the ring of nonwoven material that is drawn into the die section roughly corresponds to the circumference of the base. Very soon, however, the rings of nonwoven material that originally had an increasingly larger diameter and thus circumference are drawn into the die section. These rings are increasingly contracted as the drawing punch is moved into the die section, so that their diameter or circumference when drawn into the die section corresponds to the diameter or circumference of the inner contour of the die section.Accordingly, a ring of nonwoven material is increasingly drawn together with increasing distance from the base of the preform, with increasing amounts of fiber material being folded to a constant diameter. Thus, with increasing drawing depth, more and more nonwoven material is drawn into the drawing gap simultaneously, and the corresponding ring of nonwoven material forms an increasingly thicker wall after being drawn into the die section.

[0024] This principle applies to every curved wall section of the preform, depending on the radius of its curvature. However, this principle does not apply to any straight wall section. As the drawing punch moves into the die section, the same amount of nonwoven material is always drawn into the die section, which is why the wall thickness in a straight wall section of the preform can remain constant in the drawing direction of the drawing punch. By considering these principles, preforms with circular, oval, or approximately rectangular cross-sections can be easily formed.

[0025] The previously discussed accumulation of material in at least one curved wall section of the preform can be used during the preform pressing process to transform the preform into a conical package without the preform tearing during the pressing process. The preform is stretched at least in sections during the pressing process. However, this does not lead to the preform tearing, as the material required for the stretching is provided by the increasing wall thickness in the at least one curved wall section previously provided by the accumulation of material. This is all the more true since the preform is increasingly expanded during the pressing process with increasing distance from the base of the preform, and with increasing distance from the base of the preform, more and more material is provided for the corresponding stretching of the preform.During preforming, nonwoven material is initially accumulated in at least one curved wall section so that this wall section can be stretched, thus pulling apart, during pressing. This reverses the material accumulation, at least partially. Since the nonwoven material of the preform has only been partially pressed, it is still sufficiently malleable, especially stretchable, during pressing. The surface pressure of the preform during deep drawing should therefore be limited.

[0026] In order to provide the advantages described above, the forming device is preferably designed to carry out the method described above. Specifically, the forming device has a die with a die section which has an inner contour extending at least substantially parallel to the drawing direction and at least partially curved in a plane perpendicular to the drawing direction. As a result of the inner contour of the die section running parallel to the drawing direction, the outer contour of the formed preform remains constant in the drawing direction. Only the inner contour of the preform changes counter to the drawing direction. For this purpose, the drawing punch has a forming section with an outer contour which is curved at least partially in a plane perpendicular to the drawing direction and corresponding to the die section and tapers counter to the drawing direction, preferably continuously.

[0027] By tapering the forming section of the drawing punch, as the drawing punch is increasingly inserted into the die section, more and more material can be absorbed into the intake area of ​​the nonwoven material in the gap between the die section and the forming section. This accommodates an increasing accumulation of material in at least one curved wall section of the preform with increasing distance from the preform base. With increasing distance from the preform base, i.e., with increasing drawing depth, the gap between the die section and the forming section can accommodate not only an increasing wall thickness of the preform, but also increasing amounts of nonwoven material.The taper of the outer contour of the drawing punch is also adapted to the previously described material accumulation in the curved wall section of the preform such that, during deep drawing, the nonwoven material of the preform is pre-pressed in at least one curved wall section with an at least substantially constant surface pressure over the height of the curved wall section, thus preferably having a constant material density over the height of the curved wall section. The surface pressure is preferably between 6 N / mm. 2 and 22 N / mm 2 , especially between 10 N / mm 2 and 15 N / mm 2 .

[0028] In the area of ​​any intended straight wall section of the preform, no tapered mold section is required, since no material accumulation is to be expected here. Nevertheless, the gap width between the die section and the mold section can be selected such that a surface pressure of the nonwoven material of the preform that is at least substantially constant in the drawing direction is achieved, which can therefore have an at least substantially constant material density. This surface pressure is then also preferably between 6 N / mm 2 and 22 N / mm 2 , especially between 10 N / mm 2 and 15 N / mm 2. With regard to the preform, the invention therefore provides that it has an opening, a side wall, and a base region, wherein the side wall has at least one wall section curved about a central longitudinal axis of the preform. The preform is preferably produced by a method according to one of claims 1 to 6 and / or by means of a forming device according to one of claims 9 to 11. In the at least one curved wall section of the preform, the nonwoven material is folded in the circumferential direction about the central longitudinal axis of the preform.

[0029] For the previously described reasons of material accumulation in the at least one curved wall section of the preform, the curved wall section of the preform is increasingly folded from the bottom region towards the opening of the preform, whereby the wall thickness of the at least one curved wall section increases from the bottom region towards the opening of the preform. The increase in wall thickness is preferably designed to correspond to the folding of the nonwoven fiber material or at least continuously, in particular with a constant gradient. By folding the preform in the at least one curved wall region, the nonwoven fiber material of the preform can be at least partially unfolded again in the at least one curved wall region of the preform in order to enable expansion of the preform and stretching of the curved wall region during the subsequent pressing of the preform, without the preform tearing in the curved wall region.

[0030] In a first particularly preferred embodiment of the method, it is provided that as the drawing punch is moved into the die section, a preform is formed with an outer contour oriented at least substantially parallel to the drawing direction. This is achieved in that the die section of the die has an inner contour oriented at least substantially parallel to the drawing direction, whereby the deep drawing of the nonwoven material into a preform is simplified, more reliable, and more reproducible. This applies in any case to at least one curved wall section. However, for the same reasons, this is also preferably provided in any straight wall section of the preform. Here, too, an outer contour of the preform oriented parallel to the drawing direction is particularly preferred due to an inner contour of the die section oriented parallel to the drawing direction.

[0031] Alternatively or additionally, as the drawing punch is moved into the die section, a preform can be formed in at least one curved wall section with an inner contour inclined by at least 0.3°, preferably at least 1°, in particular at least 2°, more particularly at least 3°, relative to the outer contour of the preform, the inner contour of the die section, and / or the drawing direction. This takes into account an increase in wall thickness due to material accumulation, in particular due to wrinkling in the curved wall section, with increasing drawing depth. In addition, the inner contour of the preform can enable a surface pressure of the nonwoven material of the preform that is at least substantially constant in the drawing direction during deep drawing, regardless of the drawing depth. This makes it possible to provide a material density of the preform that is at least substantially constant in the drawing direction.

[0032] In addition to the at least one curved wall section, the preform can also have at least one straight wall section with a wall thickness that is at least substantially constant in the drawing direction. In the absence of a curvature in the straight wall section, at least substantially the same amount of nonwoven material is drawn in between the die section and the forming section of the drawing punch, regardless of the drawing depth of the preform. A varying wall thickness is therefore not necessary and, moreover, is preferably undesirable in order to provide an at least substantially constant surface pressure and / or an at least substantially constant material density of the nonwoven material in the straight wall section, which more preferably corresponds at least substantially to the at least substantially constant surface pressure or material density of the nonwoven material in the curved wall section of the preform.

[0033] The at least one straight wall section of the preform can be particularly expediently manufactured with an inner contour of the preform extending at least substantially parallel to the drawing direction and an outer contour of the preform extending at least substantially parallel to the drawing direction. For this purpose, the corresponding inner contour of the die section as well as the corresponding outer contour of the forming section of the drawing punch can be aligned parallel to the drawing direction. This leads to both a simplification of the process and a simplification of the equipment.

[0034] As the drawing punch moves into the die section, the nonwoven material of the preform can be compressed between the die section and the die section to an at least substantially constant material density with an at least substantially constant surface pressure. This allows for suitable and uniform subsequent forming by pressing the preform into a package with expansion of the preform. This is especially true if the constant surface pressure is applied both circumferentially to the drawing direction and in the drawing direction.

[0035] During deep drawing between the drawing punch and the die, at least the mold section and / or the die section are preferably heated to a temperature between 40°C and 160°C, in particular between 50°C and 140°C. This allows the fibers of the nonwoven material to slide more easily against each other during forming, so that the nonwoven material is less prone to tearing. For the same reason, the mold of the press and / or the press punch can also be heated.

[0036] Independently of this, the nonwoven material can be folded during drawing into the at least one curved wall section of the preform. In this way, a wall thickness that increases, preferably continuously, in particular with a constant gradient, in the at least one curved wall section is easily and reliably provided. The nonwoven material can be easily and reliably folded increasingly with increasing drawing depth of the preform, thereby providing a wall thickness of the preform in the curved wall section that increases, in particular continuously, with increasing distance from the base of the preform.

[0037] In the at least one straight wall section of the preform, however, the nonwoven material can preferably be drawn into the die without folds and / or with a material thickness that is at least substantially constant in the drawing direction. This simplifies the deep-drawing of the nonwoven material. Furthermore, in the straight wall sections, only a limited amount of stretching is required during subsequent pressing, which can easily be provided by stretching the at least one curved wall section. This is particularly easily achieved, for example, if the nonwoven material folded together in the at least one curved wall section during deep-drawing of the preform is at least partially unfolded again during the subsequent pressing of the preform.

[0038] To demold the deep-drawn preform, it is best to pull the drawing punch out of the die together with the preform after the preform has been formed. The preform can then be pulled off the drawing punch, expanding the preform at least in one curved wall section. Due to the low pre-compression of the preform's nonwoven material, the preform is sufficiently elastic for this purpose, so that it does not tear when pulled off the drawing punch.

[0039] The method for producing the preform can be configured as part of a method for producing a stackable package from the preform formed from the nonwoven material. After the preform has been formed according to one of claims 1 to 6, the preform can then be introduced into a press mold. The press mold has a conical inner contour to form a stackable mold. For this purpose, the preform is pressed in the press mold with a conical press die, reducing the wall thickness of the preform, at least in at least one curved wall section. The then quite rigid molds can then be stacked one inside the other as packages or further processed.

[0040] Preferably, the folds of the preform in the at least one curved wall section are at least partially pulled apart during the forming of the at least one curved wall section of the preform into the at least one curved wall section of the compression mold. In this way, the compression mold can be stretched and thus expanded relative to the preform at least in sections without the preform tearing during subsequent compression.

[0041] Furthermore, it may be preferred if the folds of the preform in the at least one curved wall section are at least partially pulled apart during the forming of the at least one straight wall section of the preform into the at least one straight wall section of the compression mold. Pulling apart the folds of the at least one curved wall section of the preform thus allows for problem-free stretching and expanding of the preform during compression in the region of a straight wall section of the preform, in which no or hardly any excess nonwoven material is present for corresponding stretching and / or expanding of the preform.

[0042] In a first particularly preferred embodiment of the forming device, it is provided that the drawing punch tapers in the forming section in at least one outer contour curved relative to the drawing direction by at least 0.3°, preferably at least 1°, in particular at least 2°, further in particular at least 3°, relative to the drawing direction. In this way, in interaction with the die section with an inner contour parallel to the drawing direction, a drawing gap geometry is created which can accommodate increasing amounts of nonwoven fiber material with increasing drawing depth. The drawing gap geometry is preferably designed such that the nonwoven fiber material undergoes pre-compaction with an at least substantially constant surface pressure, in particular to an at least substantially constant material density, in the drawing gap during deep drawing of the preform.

[0043] If required, the drawing punch can be aligned in the forming section in at least one outer contour that is straight relative to the drawing direction and at least substantially parallel to the drawing direction and / or to the die section. In other words, tapering of the forming section can be omitted in non-curved regions of the forming section. This then makes it possible to easily and reliably form, in addition to the curved wall sections of the preforms, straight wall sections of the preforms that have an at least substantially constant wall thickness in the drawing direction. Furthermore, the nonwoven material can be subjected to an at least substantially constant surface pressure in the curved wall sections and in the straight wall sections. If required, an at least substantially constant material density can thus be provided in the different wall sections.

[0044] In order to be able to pull the nonwoven material into the drawing gap or between the die section and the forming section of the drawing punch in a material-friendly and reliable manner, the die can have a circumferential radius above the die section at its end opposite the drawing direction in a transition to an edge section of the die that extends at least substantially perpendicular to the drawing direction. For a compact die, a radius between 1 mm and 3 mm may be preferred. This is an outer radius in order to achieve a rounding of the die in the area of ​​the radius in sections outwards towards the edge section. The nonwoven material can thus slide over the rounding from the edge section and / or die section into the drawing gap.Alternatively or additionally, a hold-down device can be provided in the area of ​​the edge section of the die, which gently presses the flat nonwoven material against the edge section of the die before it is drawn into the drawing gap. This ensures a uniform and reproducible drawing of the nonwoven material into the drawing gap between the die section and the forming section of the drawing punch. In particular, this achieves uniform pleating, especially in at least one curved wall section of the preform.

[0045] Alternatively or additionally, a counterholder can be provided adjacent to the free end of the drawing punch. This counterholder is brought closer to the nonwoven material on the other side of the drawing punch and gently presses the nonwoven material in the area of ​​the base of the preform, i.e., at the free end of the drawing punch, against the free end of the drawing punch during the deep drawing of the preform. For this purpose, the counterholder is retracted into the die section together with the drawing punch, particularly uniformly.

[0046] In a first particularly preferred embodiment of the preform, the outer contour of the at least one curved wall section is aligned at least substantially parallel to a central longitudinal axis of the preform. Such a preform can be manufactured particularly easily and reliably. An inner contour of the die section during deep-drawing of the preform can serve this purpose, which is also aligned at least substantially parallel to a central longitudinal axis of the preform and / or the drawing direction during deep-drawing.

[0047] Alternatively or additionally, it is advisable if the inner contour of the at least one curved wall section tapers at least substantially between the base region and the opening. In this way, the nonwoven material can be accumulated or folded in the at least one curved wall section during deep drawing, which is then later available for widening and expanding the preform when the preform is pressed into the mold or the subsequent stackable packaging. The tapered inner contour of the preform in the at least one curved wall section is also advantageous because it means that the nonwoven material of the preform in the at least one curved wall section does not have to be pressed too hard during preforming, particularly in the region of the preform opening, and thus does not have to be compressed too much. The preform can therefore still be reliably formed during the subsequent pressing without tearing.

[0048] To ensure simple and reproducible preform production, it is advantageous for the side wall, at the end opposite the base region, to transition into an edge region extending at least substantially perpendicular to a central longitudinal axis of the preform. In this edge region, the nonwoven material can be lightly pressed against the die by a hold-down device during the deep-drawing of the preform. The nonwoven material can then be drawn into the drawing gap in a defined manner and, in particular, folded in a defined manner. The edge region can be used alternatively or additionally to form an edge of the subsequent packaging.

[0049] In order to provide a relatively constant surface pressure and / or material density of the nonwoven fiber material of the preform in different sections of the preform, it is advisable if the base region and the end of the at least one curved wall section adjacent to the base region have at least substantially the same wall thickness. In both sections, the nonwoven fiber material is not folded or not significantly folded and thus not or not significantly accumulated. The opposite is the case in the edge region adjacent to the curved wall regions and in the end of the at least one curved wall section adjacent to the edge region. However, the folding and material accumulation is comparable in these sections, which is why it is advisable if at least substantially the same wall thickness is also provided in these sections of the preform.In order to be able to provide packaging with a wide variety of shapes, the side wall can have at least one straight wall section extending parallel to a central longitudinal axis of the preform. Corresponding wall sections can be used to form at least approximately straight side walls of the packaging. To ensure that the surface pressure and / or material density of the preform is as uniform as possible in different sections of the preform, it is advisable for the at least one straight wall section to have an at least substantially constant wall thickness, at least substantially between the base region and the opening of the preform.In the case of the straight wall section of the preform, unlike in the at least one curved wall section, during deep drawing, approximately the same amount of nonwoven material is always drawn into the drawing gap with increasing drawing depth, wherein the amount of nonwoven material corresponds to the amount of nonwoven material used to form the base of the preform. Both in the region of the base and in the region of the at least one straight wall section, the nonwoven material is preferably provided in a single layer and not folded. In the at least one curved wall section, however, the nonwoven material is preferably provided folded, and the more so with increasing distance from the base of the preform.

[0050] Therefore, it is alternatively or additionally also preferred if the wall thickness of the at least one straight wall section is at least equal to the wall thickness of the base region and / or the end of the at least one curved wall section adjacent to the base region. In all of these regions, the nonwoven material is preferably provided in at least substantially one layer, so that the same or at least very similar wall thicknesses and, in particular, material densities of the preform are achieved with the desired uniform surface pressure.

[0051] Since no material accumulation and folding of the nonwoven material depending on the drawing depth has to be taken into account in the at least one straight wall section, it is advisable for the sake of easier deep drawing of the preform if the inner contour and the outer contour of the at least one straight wall section extend at least substantially parallel to the one central longitudinal axis of the preform.

[0052] For the reasons stated above, preforms according to the invention can have a draw ratio of greater than 0.3, preferably greater than 0.5, in particular greater than 0.75, and more particularly greater than 1.0. The draw ratio corresponds to the ratio of the preform's height to its minimum outer width. For preforms with a circular base region, the draw ratio therefore corresponds to the ratio of the preform's height to its outer diameter.

[0053] The invention is explained in more detail below with reference to a drawing which merely illustrates exemplary embodiments. The drawing shows

[0054] Fig. 1 shows a forming device according to the invention in a schematic side view,

[0055] Fig. 2A-B preforms according to the invention with a round bottom and an approximately rectangular bottom in a perspective view,

[0056] Fig. 3A-C steps of a method according to the invention for producing a preform in a schematic sectional view,

[0057] Fig. 4A-B a preform according to the invention in different states in a sectional view and

[0058] Fig. 5 a detail of the preform from Fig. 2B in a view from above,

[0059] Fig. 6A-B the inventive forming of a straight wall section and a curved wall section of a preform from Fig. 5 corresponding to the sectional planes VIA-VIA and V1B-V1B of Fig. 5 by deep drawing in a schematic sectional view, Fig. 7A-B inventive compression molds produced from the preforms according to Fig. 2A-B in a perspective view.

[0060] Fig. 1 schematically shows a forming device 1 for deep-drawing preforms 2 from a nonwoven fiber material 3 and for pressing the preforms 2 into a mold 4 or a packaging. The nonwoven fiber material 3 is delivered as a roll, drawn off the roll 5 and cut to size in a cutting station 6. For this purpose, the cutting station 6 has a support 7 and cutting edges 8, between which the nonwoven fiber material 3 is provided. The blanks 9 produced in the cutting station 6 are deep-drawn into preforms 2 in a deep-drawing station 10, each separately but simultaneously. For this purpose, the deep-drawing station 10 comprises a die 11 and a drawing punch 12 for each blank 9, with which the respective blank 9 of the nonwoven fiber material 3 is drawn into the die 11.After the drawing punch 12 has been pulled out of the die 11 together with the preform 2, the respective preform 2 is removed from the drawing punches 12 and inserted into a mold 14 of a press 15 in a pressing station 13, where the preforms 2 are pressed into a conical and therefore stackable press mold 4 or packaging by a press punch 16 immersed in the mold 14 of the press 15. The press molds 4 are then transferred to a punching station 17, where the edges of the press molds 4 are punched to size by removing excess nonwoven material 3. After the edges of the press molds 4 have been formed in the punching station 17, the press molds 4 or packaging are stacked one after the other in a stack 19 or in several stacks in a stacking station 18.

[0061] Since the step of preforming the blanks 9 from nonwoven material 3 takes longer than the other steps of the previously described method, the cutting station 6, the pressing station 13, the punching station 17 and the stacking station 18 are operated at a cycle that is half as long as the cycle of the deep-drawing station 10. Thus, in the illustrated and thus preferred method, four blanks 20 are each processed in one cycle in the cutting station 6, the pressing station 13, the punching station 17 and the stacking station 18, while eight blanks 20 are each processed in one cycle in the deep-drawing station 10. This is illustrated by the individual blanks 20 in the form of blanks 9, which are shown under the respective stations 6, 10, 13, 17, 18 in Fig. 1.

[0062] Fig. 2A shows a perspective view of a preform 2. The preform 2 has a circular base region 21, a side wall 22 with an at least substantially constant radius around a central longitudinal axis L of the preform 2, and an edge region 24 encompassing an opening 23 of the preform 2. The side wall 22 can be understood as consisting of a single, completely circumferential, curved wall section 25. The preform 2 is deep-drawn from a flat blank 9 of a nonwoven material 3. Starting from the region of the nonwoven material 3 forming the base region 21 of the preform 2, rings with a constant width can be defined around this base region 21. The further these rings are away from the base region 21, the larger the circumference of these rings and the more nonwoven material 3 these rings encompass.The further the base region 21 is removed from the flat region of the nonwoven fiber material 3 during deep drawing, the larger the rings of the same width with a larger circumference and more fiber material 3 are drawn into the drawing gap, although the outer diameter of the drawing gap does not change. The individual rings of the flat nonwoven fiber material 3 must therefore be pulled together until they correspond to the circumference of the drawing gap. Rings with a larger original circumference, which are drawn into the drawing gap later, must be pulled together and folded more strongly in order to fit into the drawing gap than rings with a smaller circumference, which are drawn into the drawing gap earlier. In the case of the preform 2, this results in the wall thickness of the side wall 22 increasing from the base region 21 towards the edge region 24 and / or the opening 23 of the preform 2, and in the case of the preform 2 shown, this increases continuously and with a constant gradient a.The folding of the nonwoven material 3 during the deep-drawing of the preform 2 is illustrated by the lines in the edge region, which extend toward the opening 23 of the preform. Furthermore, the folds 27 of the nonwoven material 3 of the side wall 22 are illustrated by the lines extending from the opening 23 toward the bottom region 21.

[0063] Fig. 2B shows a preform 28 comprising an approximately rectangular base region 29 with rounded corners 30, a side wall 31 with curved wall sections 32 and with straight wall sections 33, which are provided alternately in the circumferential direction, and an edge region 34 which encompasses an opening 35 of the preform 28. According to the principle described above, the further the base region 29 is spaced from the flat nonwoven material 3, i.e., deep-drawn, the more nonwoven material 3 is drawn into the curved wall sections 32. At each curved wall section 32, ring sections extending over approximately 90° are drawn into the drawing gap; these ring sections are longer and therefore encompass more nonwoven material 3, the further these ring sections were originally spaced from the base region 29.The longer the corresponding ring sections, the more they must be pulled together and folded in order to be able to be drawn into the drawing gap.

[0064] The situation is different at the straight wall sections 33, where a single-layer strip of nonwoven fiber material 3 of the same width is always drawn into the drawing gap during deep drawing. As a result, the wall thickness in the straight wall sections 33 between the base region 29 and the edge region 34 is at least substantially constant, while the wall thickness in the curved wall sections 32 increases continuously and with a constant gradient a from the base region 29 to the edge region 34. As illustrated by the lines extending in the edge region 34 in the direction of the curved wall sections 32 and by the lines extending in the curved wall sections 32 from the edge region 34 in the direction of the base region 29, the nonwoven fiber material 3 is folded only in the curved wall sections 32 and the sections of the edge region 34 adjoining the curved wall sections 32.In the straight wall sections 33, the nonwoven material 3 is not folded, nor in the adjoining sections of the edge region 34.

[0065] 3A-C illustrate the deep drawing of a preform 28 in a deep drawing station 10 in a sectional view in the region of at least one curved wall section 32. As shown in Fig. 3A, the flat blank 9 of the nonwoven fiber material 3 is first placed on the die 11. Subsequently, a drawing punch 12 with its free end and, on the other side of the nonwoven fiber material 3, a counterholder 36 are moved towards the nonwoven fiber material 3 in such a way that the nonwoven fiber material 3 is slightly compressed in the base region 29 of the preform 28 between the drawing punch 12 and the counterholder 36. From the side of the drawing punch 12, a hold-down device 37 is also moved towards the flat nonwoven fiber material 3. The hold-down device 37 presses the nonwoven material 3 lightly against the edge section 38 of the die 11, which is aligned at least substantially perpendicular to the drawing direction Z and parallel to the flat nonwoven material 3.

[0066] The drawing punch 12 is then moved into a die section 39 of the die 11 in the drawing direction Z indicated by the arrow as shown in Fig. 3B. During this process, the counterholder 36 is also moved into the die section 39. A drawing gap 41 is formed between the die section 39 and a drawing section 40 of the drawing punch 12 at the free end of the drawing punch 12, through which gap the nonwoven material 3 is increasingly drawn into the drawing gap 42 between a forming section 43 of the drawing punch 12 and the die section 39. In the illustrated and in this respect preferred drawing punch 12, the forming section 43 is provided directly adjacent to the drawing section 40 of the drawing punch 12. In order to protect the nonwoven material 3 when it is drawn into the die section 39 and in particular to prevent it from kinking, a rounded transition area 44 is provided between the die section 39 and the edge section 38 of the die 11.In this transition region 44, the die 11 has an at least substantially uniform radius all around.

[0067] The drawing punch 12 is provided in the forming section 43 with an outer contour that tapers at least in sections, counter to the drawing direction Z. The outer contour of the forming section 43 is provided with a constant inclination a to the drawing direction in the illustrated section, while the inner contour of the die section 39 is aligned parallel to the drawing direction. The die section 39 and the forming section 43 are curved in the circumferential direction in order to form a curved wall section 32 of the preform 28 between them.

[0068] As a result of the at least section-wise tapering of the drawing punch 12 in the forming section 43, as shown in Fig. 3C, the drawing gap 42 between the forming section 43 of the drawing punch 12 and the die section 39 at the upper edge of the die section 39 increasingly widens, i.e. with increasing drawing depth T of the preform 28. More and more fiber fleece material 3 can be accommodated in the widening drawing gap 42. With the same surface pressure of the fiber fleece material 3 in the drawing gap 42, more fiber fleece material 3 can be accommodated to the extent that with increasing drawing depth T more fiber fleece material 3 is drawn into the drawing gap 42 in folded form in the curved wall region 32 of the preform 28.

[0069] To demold the preform 28, the drawing punch 12 can be pulled out of the die 11 together with the preform 28. The preform 28 has only been slightly pre-compressed during deep drawing, so that the preform 28 can be pulled off the drawing punch 12 easily and without damage before the drawing punch 12 is used to deep draw another preform 28. In Fig. 4A, the preform 28 is shown in the same view as in Figs. 3A-C in a state still sitting on the drawing punch 12, although the drawing punch 12 is not shown for the sake of clarity. In the state shown in Fig. 4A, the preform 28 has an outer contour which, like the inner contour of the die section 39, extends in the corresponding area parallel to the drawing direction Z of the drawing punch 12.The base region 29 of the preform 28 is aligned at least substantially at a right angle to the outer contour in at least one curved wall section 32. The inner contour of the preform 28 is tapered upwards towards the opening 35 of the preform 28 in the illustrated at least one curved wall section 32. The inner contour is inclined inwards, in the same way as the forming section 43 of the drawing punch 12, continuously and with a constant gradient a, counter to the drawing direction Z or a central longitudinal axis L. The inclination a can be, for example, at least 0.3°, preferably at least 1°. At the transition of the base region 29 to the side wall 31 and at the transition of the side wall 31 to the edge region 34, the preform 28 has a rounded portion, which, however, is not shown for the sake of clarity.

[0070] When the preform 28 is pulled off the drawing punch 12, the preform 28 is expanded in the region of the at least one curved wall section 32. The preform 28 pulled down by the drawing punch 12 can therefore assume the shape shown in Fig. 4B in the at least one curved wall section 32, in which the inner contour of the preform 28 in the at least one curved wall section 32 is aligned at least substantially parallel to the drawing direction Z or a central longitudinal axis L and at least substantially perpendicular to the base region 29. The outer contour of the at least one curved wall section 32 expands counter to the drawing direction Z or a central longitudinal axis L. At the transition of the base region 29 to the side wall 31 and at the transition of the side wall 31 to the edge region 34, the preform 28 each has a rounded portion, which, however, is not shown for the sake of clarity. Fig. 5 shows a detail of the preform 28 from Fig.2B in a top view, wherein the detail comprises a curved wall section 32 and a straight wall section 33. Due to the viewing direction, only the associated edge regions 34 of the preform 28 and the base region 29 with a straight edge 45 and a rounded corner 30 are shown. The deep drawing of the straight wall section 33 and the curved wall section 32 of the preform 28 is shown in Figs. 6A-B, wherein the preform 28 is shown in sectional views corresponding to the section planes VI-VIA and VIB-VIB of Fig. 5.

[0071] According to Fig. 6A, the drawing punch 12 has been moved with its forming section 43 in the drawing direction Z into the die section 39. The nonwoven material 3 is lightly held between an edge section 38 of the die 11 and a hold-down device 37, so that the nonwoven material 3 can be drawn further into the drawing gap 42 between the forming section 43 of the drawing punch 12 and the die section 39 as the drawing punch 12 is moved further into the die section 39. Opposite the free end of the drawing punch 12, the nonwoven material 3 is pressed lightly against the free end of the drawing punch 12 by a counter-holder 36, while the drawing punch 12 is moved further in the drawing direction Z into the die section 39. In the area shown, the die section 39 has an inner contour that extends parallel to the drawing direction Z. The upper side of the edge portion 38 of the die 11 extends at least substantially perpendicular thereto.The same applies in the illustrated and in this respect preferred embodiment for the free end of the drawing punch 12 and the upper side of the counter-hold 36. The outer contour of the forming section 43 of the drawing punch 12 extends parallel to the drawing direction Z and thus parallel to the inner contour of the die section 39.

[0072] Consequently, the drawing gap 42 between the die section 39 and the forming section 43 of the drawing punch 12 in the illustrated straight wall section 33 of the preform 28 is constant in the drawing direction Z. The nonwoven material 3 is provided in a single layer in the drawing gap 42, wherein the drawing gap 42 is selected to be wide enough so that the nonwoven material 3 is slightly pre-compacted and a uniform surface pressure of between 6 N / mm 2 and 22 N / mm 2This preferably leads, with a suitable original nonwoven fiber material, to a uniform material density in the straight wall section 33 of the preform 28. The nonwoven fiber material 3 is pre-compacted to the same extent in the bottom region 29. In the edge region 34 of the preform 28, however, the nonwoven fiber material 3 is less strongly compacted so that the nonwoven fiber material 3 can flow into the drawing gap 42 without great resistance. The preform 28 has a wall thickness dl in the edge region 34 that is greater than the wall thickness d2 in the drawing gap 42 and the wall thickness d3 in the bottom region 29, wherein the bottom region 29 and the straight wall section 33 have a constant and identical wall thickness d2=d3.

[0073] Fig. 6B shows the deep drawing of a curved wall section 32 in a cross-section. This is carried out in many ways as previously described in connection with the deep drawing of the straight wall section 33. In contrast to the deep drawing of the straight wall section 33 according to Fig. 6A, however, when deep drawing the curved wall section 32 according to Fig. 6B, the outer contour of the forming section 43 of the drawing punch 12 is not aligned parallel to the drawing direction Z and to the inner contour of the die section 39. Rather, the forming section 43 of the drawing punch 12 tapers in a direction opposite to the drawing direction Z. The forming section 43 is inclined by a constant angle α relative to the drawing direction Z, so that the drawing gap 42 between the forming section 43 and the die section 39, which has an inner contour parallel to the drawing direction Z, becomes wider in a direction opposite to the drawing direction Z with a corresponding constant gradient α.

[0074] The drawing gap 42 is completely filled with nonwoven material 3 over its entire height. The nonwoven material 3 folds before being drawn into the drawing gap 42, and this folds more and more the deeper the drawing punch 12 is inserted into the die 11. Thus, as the drawing punch 12 moves further in and the drawing depth T increases, more and more nonwoven material 3 is drawn into the drawing gap 42, with the drawn-in fiber material 3 being provided with more and more space due to the widening drawing gap 42.In the illustrated and thus preferred embodiment, the increase in the width of the drawing gap 42 corresponds to the increase in the fiber nonwoven material 3 to be drawn in and its folding, so that the surface pressure of the fiber nonwoven material 3 in the curved wall section 32 in the drawing direction Z is at least substantially constant and also at least substantially corresponds to the surface pressure of the fiber nonwoven material 3 in the straight wall section 33 and in the base region 29. This preferably results in a preform 28 in which the material density in the curved wall section 32 in the drawing direction Z is at least substantially constant and at least substantially corresponds to the material density in the straight wall section 33 and in the base region 29.

[0075] The nonwoven material 3 is folded not only in the curved wall section 32, but also in the edge region 34. In the edge region 34, however, the surface pressure of the nonwoven material 3 by the hold-down device 37 is lower than in the drawing gap 42. For this reason, the wall thickness or thickness dl of the nonwoven material 3 in the edge region 34 of the preform 28 is at least approximately the same as the wall thickness d2 of the nonwoven material 3 at the upper end of the drawing gap 42 between the forming section 43 of the drawing punch 12 and the die section 39. However, the wall thicknesses dl, d2 of the preform 28 are greater at both of the above-mentioned locations than the wall thicknesses d3, d4 at the lower end of the drawing gap and the base region 29, the latter wall thicknesses d3, d4 in turn being at least approximately the same.

[0076] After being removed from the drawing punch 12, the preforms 2, 28 are pressed into a mold 14 of a press 15 in a pressing station 13 using a pressing punch 16. The pressing is preferably carried out using a mold 14 heated to 100°C to 200°C and / or using a pressing punch 16 heated to 100°C to 200°C. The pressing can produce the compression molds 46, 47 shown in Figs. 7A-B. The compression molds 46, 47 can be used directly as packaging or further processed, for example, provided with a plastic coating. In this process, not only is the wall thickness of the preform 2, 28 reduced, but the preform 2, 28 is also formed into the compression mold 46, 47. The compression mold 46, 47 thus takes on a conical shape that allows the compression molds 46, 47 to be stacked inside one another. The surface pressure when pressing the preform 2.28 is between 20 N / mm 2 and 30 N / mm 2The section-wise widening of the preform 2, 28 during pressing leads to an elongation of at least one curved wall region 25, 32 and thus to an at least partial unfolding of the nonwoven material 3 in this region.

[0077] Fig. 7A shows a mold 46 with a circular base region 48, a circular edge region 49, and a circumferentially curved wall section 50 connecting the edge region 49 and the base region 48. This mold 46 is preferably made from a preform 2 according to Fig. 2A. The diameter of the curved wall section 32 becomes increasingly larger between the base region 48 and the edge region 49, so that similar molds 46 can be easily stacked inside one another. Fig. 7B shows a mold 47 with an approximately rectangular base region 51 with rounded corners 52. The mold 47 is preferably made from a preform 28 according to Fig. 2B. Straight wall sections 53 alternate with curved wall sections 54, each of which merges into an edge region 55 at the end facing away from the floor region 51.The straight wall sections 53 and the curved wall sections 54 slope outward from the base region 51 to the edge region 55 to achieve a conical and thus stackable shape of the mold 47. By tilting the straight and curved wall sections 53, 54, the nonwoven material 3 of the preform 28 is partially unfolded in the curved wall sections 32 to provide nonwoven material 3 for forming the preform 28 in the pressing station 13. List of reference symbols.

[0078] 1 forming device 31 side wall

[0079] 2 Preform 32 curved wall section

[0080] 3 nonwoven material 33 straight wall section

[0081] 4 Press mold 34 edge area

[0082] 5 roll 35 opening

[0083] 6 cutting stations 36 counterholders

[0084] 7 support 37 hold-down device

[0085] 8 cutting edge 38 edge section

[0086] 9 Cutting 39 Die section

[0087] 10 deep drawing station 40 drawing section

[0088] 11 Die 41,42 Drawing gap

[0089] 12 drawing punch 43 mold section

[0090] 13 Pressing station 44 Transition area

[0091] 14 Form 45 Edge

[0092] 15 Press 46,47 Press mold

[0093] 16 Press ram 48 Bottom area

[0094] 17 Punching station 49 Edge area

[0095] 18 Stacking station 50 curved wall section

[0096] 19 Stack 51 Floor area

[0097] 20 Benefits 52 Corner

[0098] 21 floor area 53 straight wall section

[0099] 22 side wall 54 curved wall section

[0100] 23 Opening 55 Edge area

[0101] 24 Edge area a Gradient / Angle

[0102] 25 curved wall section d wall thickness

[0103] 27 folds L central longitudinal axis

[0104] 28 Preform T drawing depth

[0105] 29 Bottom area Z pulling direction

Claims

P a t e n t a n s p r ü c h e 1. A method for producing a preform (2, 28) for further processing into a packaging made of a flat nonwoven fiber material (3) by deep drawing, comprising a die (11) and a drawing punch (12) which can be moved into the die (11) in a drawing direction, wherein the die (11) has a die section (39) with an inner contour extending at least substantially parallel to the drawing direction (Z) and curved at least in sections in a plane perpendicular to the drawing direction (Z), and wherein the drawing punch (12) has a mold section (43) with an outer contour which is curved at least in sections in a plane perpendicular to the drawing direction (Z) and corresponding to the die section (39) and at least in sections opposite to the drawing direction (Z), preferably continuously,in which the nonwoven material (3) is arranged between a die (11) and a drawing punch (12) and then the drawing punch (12) is moved into the die section (39) in the drawing direction (Z), in which during the moving of the drawing punch (12) into the die section (39) the nonwoven material (3) is deep-drawn at least in sections in a drawing gap (42) between the die section (39) and a drawing section (40) of the drawing punch (12), in which during the moving of the drawing punch (12) into the die section (39) between the die section (39) and the forming section (43) a preform with at least one curved wall section (25, 32) in a plane perpendicular to the drawing direction (Z) and with a wall thickness which increases, preferably continuously, in the at least one curved wall section (25, 32) counter to the drawing direction (Z) (d2,d4) is formed., 2. Method according to claim 1, in which, during the insertion of the drawing punch (12) into the die section (39), a preform (2, 28) with an outer contour aligned at least substantially parallel to the drawing direction (Z), in any case in at least one curved wall section (25, 32), is formed, and in which, preferably, during the insertion of the drawing punch (12) into the die section (39), a preform (2, 28) with an inner contour inclined by at least 0.3°, preferably at least 1°, in particular at least 2°, further in particular at least 3°, with respect to the outer contour of the preform (2, 28), the inner contour of the die section (39) and / or the drawing direction (Z), is formed in at least one curved wall section (25, 32).

3. Method according to claim 1 or 2, in which the preform (28) has at least one straight wall section (33) with a wall thickness (d2) that is at least substantially constant in the drawing direction (Z) and in which, preferably, the at least one straight wall section (33) has an inner contour that extends at least substantially parallel to the drawing direction (Z) and an outer contour that extends at least substantially parallel to the drawing direction (Z).

4. Method according to one of claims 1 to 3, wherein during the insertion of the drawing punch (12) into the die section (39), the nonwoven material (3) of the preform (2, 28), in particular circumferentially to the drawing direction (Z) and in the drawing direction (Z), between the die section (39) and the forming section (43) with an at least substantially constant surface pressure, preferably between 6 N / mm 2 and 22 N / mm 2 , especially between 10 N / mm 2 and 15 N / mm 2, is compressed and / or in which during the insertion of the drawing punch (12) into the die section (39) at least the mold section (43) and / or the die section (39) heated to a temperature between 40°C and 160°C, in particular between 50°C and 140°C.

5. Method according to one of claims 1 to 4, in which in the at least one curved wall region (25, 32) the nonwoven material (3) is folded when the nonwoven material (3) is drawn into the die (11) and in which, preferably, in the at least one straight wall section (33) the nonwoven material (3) is drawn into the die (11) without folds and / or with a material thickness that is at least substantially constant in the drawing direction (Z).

6. Method according to one of claims 1 to 5, in which the drawing punch (12) is pulled out of the die (11) after the preform (2,28) has been formed and in which, preferably, the preform (2,28) is then pulled by the drawing punch (12) with the preform (2,28) being widened at least in at least one curved wall section (25,32).

7. A method for producing a stackable packaging from a preform (2, 28) formed from a nonwoven material (3), in which the preform (2, 28) is formed according to one of claims 1 to 6, in which the preform (2, 28) is introduced into a mold (4) of a press with a conical inner contour and is pressed in the mold (4) with a conical press die (16) while reducing the wall thickness (dl-d4) of the preform (2, 28), at least in at least one curved wall section (25, 32), and in which, preferably, successively pressed packages are stacked one inside the other.

8. The method according to claim 7, wherein the folds (27) of the preform (2, 28) in the at least one curved wall section (25, 32) are at least partially pulled apart when the at least one curved wall section (25, 32) of the preform (2, 28) is formed into at least one curved wall section (25, 32) of the press mold and / or wherein the folds (27) of the preform (28) in the at least one curved wall section (32) are at least partially pulled apart when the at least one straight wall section (33) of the preform (28) is formed into at least one straight wall section (53) of the press mold.

9. Forming device (1) for producing a preform (2, 28) from a flat fiber nonwoven material (3) by deep drawing, preferably by means of the method according to one of claims 1 to 8, with a die (11) and a drawing punch (12) which can be moved into the die (11) in a drawing direction (Z), characterized in that the die (11) has a die section (39) with an inner contour which extends at least substantially parallel to the drawing direction (Z) and is curved at least in sections in a plane perpendicular to the drawing direction (Z), and wherein the drawing punch (12) has a forming section (43) with an outer contour which is curved at least in sections and corresponding to the die section (39) in a plane perpendicular to the drawing direction (Z) and tapers at least in sections counter to the drawing direction (Z), preferably continuously.

10. Forming device according to claim 9, characterized in that the drawing punch (12) extends in the forming section (43) in at least one outer contour curved relative to the drawing direction (Z) by at least 0.3°, preferably at least 1°, in particular at least 2°, further in particular at least 3°, tapered relative to the drawing direction (Z) and / or the drawing punch (12) in the mold section (43) is aligned in at least one outer contour which is straight relative to the drawing direction (Z) at least substantially parallel to the drawing direction (Z) and / or to the die section (39).

11. Forming device according to claim 9 or 10, characterized in that the die (11) above the die section (39) at its end opposite the drawing direction (Z) in a transition to an edge section (38) of the die (11) extending at least substantially perpendicular to the drawing direction (Z) has a circumferential radius, in particular between 1 mm and 3 mm.

12. Preform (2, 28) made of a nonwoven material (3) for further processing into a packaging, preferably produced by a method according to one of claims 1 to 6 and / or by means of a forming device (1) according to one of claims 9 to 11, with an opening (23, 35), a side wall (22, 31) and a base region (21, 29), wherein the side wall (22, 31) has at least one wall section (25, 32) curved about a central longitudinal axis (L) of the preform (2, 28), characterized in that the nonwoven material (3) in the at least one curved wall section (25, 32) is increasingly folded in the circumferential direction about the central longitudinal axis (L) of the preform (2, 28) from the base region (21, 29) in the direction of the opening (23, 35) of the preform (2, 28) and that the wall thickness (d2, d4) of the at least a curved wall section (25,32) from the bottom area (21,29) towards the opening (23,35) of the preform (2,28),preferably corresponding to the folding of the nonwoven material (3) or at least substantially continuously, 13. Preform according to claim 12, characterized in that the outer contour of the at least one curved wall section (25, 32) is aligned at least substantially parallel to a central longitudinal axis (L) of the preform (2, 28) and / or the inner contour of the at least one curved wall section (25, 32) tapers at least substantially between the base region (21, 29) and the opening (23, 35) and / or that the side wall (22, 31) at the end opposite the base region (21, 29) merges into an edge region (24, 34) extending at least substantially perpendicular to a central longitudinal axis (L) of the preform (2, 28) and / or that the base region (29, 48) and the end of the at least one curved wall section (25, 32) adjacent to the base region (21, 29) and / or the edge region (24, 34) the end of the at least one curved wall section (25,32) have at least substantially the same wall thickness (dl-d4).

14. Preform according to claim 12 or 13, characterized in that the side wall (31) has at least one straight wall section (33) extending parallel to a central longitudinal axis (L) of the preform (28) and that, preferably, the at least one straight wall section (33) has an at least substantially constant wall thickness (d2) at least substantially between the bottom region (29) and the opening (35) of the preform (28).

15. Preform according to claim 14, characterized in that the wall thickness (d2) of the at least one straight wall section (33) is at least equal to the wall thickness (d3, d4) of the base region (29) and / or the the end of the at least one curved wall section (25, 32) adjacent to the base region (29) and / or that the inner contour and the outer contour of the at least one straight wall section (33) extend at least substantially parallel to a central longitudinal axis (L) of the preform (28).

Images