Method and pressing device for producing a compression mould, and compression mould

Abstract

The invention relates to a method for producing a compression mould (49, 50), for use as packaging or for further processing to form packaging, from a preform (2, 28) which is formed at least substantially from a nonwoven material (3) and comprises an opening (23, 35), a side wall (22, 31), and a bottom region (21, 29), wherein the side wall (22, 31) has at least one wall portion (25, 32) that is curved about a central longitudinal axis (L) of the preform (2, 28), wherein the wall thickness (d2, d4) of the at least one curved wall portion (25, 32) of the side wall (22, 31) of the preform (2, 28) increases, preferably continuously, in said at least one curved wall portion (25, 32) from the bottom region (21, 29) in the direction of the opening (23, 35) of the preform (2, 28), in which method: the preform (2, 28) is placed into a die (14) of a press (15) having a conical inner contour and is pressed in the die (14) by means of a conical press punch (16), thereby reducing the wall thickness (d1-d4) of the preform (2, 28) and expanding the preform (2, 28) at least in at least one curved wall portion (25, 32); and, during the pressing of the preform (2, 28), at least one curved wall portion (47) of the compression mould (49, 50) is formed with a wall thickness (s2) that increases from the bottom region (51, 52) in the direction of the opening (55, 56).

Description

[0001] Method and pressing device for producing a pressing mold and pressing mold

[0002] The invention relates to a method for producing a compression mold for use as packaging or for further processing into packaging. The invention further relates to a pressing device for producing a compression mold for use as packaging or for further processing into packaging, comprising a press comprising a mold and a compression ram configured to correspond to the mold and retractable into the mold in a pressing direction, wherein the mold has an inner contour extending at least substantially conically from a base to an opening of the mold and the compression ram has an outer contour extending at least substantially conically in the direction of the free end of the compression ram for forming compression molds that can be stacked one inside the other.Furthermore, the invention relates to a mold for producing a mold for use as packaging or further processing into a packaging, at least substantially made of a nonwoven material, with an opening, a side wall and a bottom region, wherein the side wall has at least one wall section curved about a central longitudinal axis of the mold.

[0003] Depending on the application, plastic packaging can be produced in a wide variety of forms. In many cases, thermoforming machines are used to transform a flat plastic into a three-dimensional package. However, large quantities of such plastic packaging enter the environment, where it is usually not biodegradable and is thus mechanically broken down over time into unwanted microplastics. To prevent this, increased effort is required to return and recycle the plastic packaging. 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 economically in a few forms, as the fiber materials are less malleable than thermoplastics, in particular. This is especially true for packaging made from a nonwoven material, such as a nonwoven made of cellulose fibers, which is therefore particularly environmentally friendly.

[0004] 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 packaging, and then to press this preform into a mold. This occurs in a single operation using a correspondingly shaped drawing and pressing die and a corresponding die and mold of the press. The drawing and pressing die, as well as the die and mold, are each designed as a single component.

[0005] 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 mold. The curvature can have a constant radius arranged in a plane around a central longitudinal axis of the mold. 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 mold. However, molds with an oval base area and molds with a base area that has a straight edge in sections are also conceivable, from which packaging with an approximately rectangular base with rounded edges can be produced.

[0006] 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.

[0007] Therefore, the object of the present invention is to design and further develop the method, the pressing device and the pressing mold 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.

[0008] This object is achieved according to claim 1 by a method for producing a compression mold for use as packaging or further processing into a packaging from a preform formed at least substantially from a nonwoven material with an opening, a side wall and a bottom region, wherein the side wall has at least one wall section curved about a central longitudinal axis of the preform, wherein the wall thickness of the at least one curved wall section of the side wall of the preform increases in the at least one curved wall section from the bottom region towards the opening of the preform, preferably continuously,

[0009] - 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, reducing the wall thickness of the preform and expanding the preform at least in at least one curved wall section, and

[0010] - wherein, during the pressing of the preform, at least one curved wall section of the pressing mold is formed, with a wall thickness increasing from the base region toward the opening. The aforementioned object is further achieved in a pressing device according to the preamble of claim 9 in that the inner contour of the mold is more steeply inclined in at least one pressing section of the mold curved around the pressing direction than the corresponding outer contour of the pressing ram in at least one pressing section curved around the pressing direction.

[0011] Furthermore, the above-mentioned object is achieved in a press mold according to the preamble of claim 12 in that the wall thickness of the at least one curved wall section of the side wall of the press mold in the at least one curved wall section increases, preferably continuously, from the bottom region in the direction of the opening of the press mold.

[0012] To produce a preform for further processing into a packaging from a flat nonwoven fiber material by deep drawing, a method can be used which uses 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 tapers at least in sections counter to the drawing direction, preferably continuously.The nonwoven material can be arranged between a die and a drawing punch, and the drawing punch can then be moved into the die section in the drawing direction, with the nonwoven material being deep-drawn at least in sections in a drawing gap between the die section and a drawing section of the drawing punch. A preform is formed between the die section and a forming section of the drawing punch, with at least one curved wall section in a plane perpendicular to the drawing direction and with a wall thickness that increases, preferably continuously, in the at least one curved wall section counter to the drawing direction.

[0013] To carry out a corresponding method for producing the preform, a forming device can be used, wherein the die has a die section with an inner contour extending at least substantially parallel to the drawing direction and curved at least in sections in a plane perpendicular to the drawing direction. Furthermore, the drawing punch can have a forming section with an outer contour that is curved at least in sections in a plane parallel to the drawing direction and corresponding to the die section, and that tapers at least in sections, preferably continuously, counter to the drawing direction.

[0014] A correspondingly produced preform, if required, has an opening, a side wall, and a base region, wherein the side wall comprises at least one wall section curved around a central longitudinal axis of the preform, and the nonwoven 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 toward the opening of the preform. Consequently, the wall thickness of the at least one curved wall section can increase from the base region toward the opening of the preform, preferably corresponding to the folding of the nonwoven material or at least substantially continuously.

[0015] The nonwoven material can preferably be one produced using the so-called airlaid process. In this process, the fibers are layered on top of one another using an air stream to form a nonwoven web. The nonwoven web forms a loose nonwoven fabric that is made durable using pressure or binding agents. "Pressure" here simply means 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 and 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 be made more moisture-resistant.

[0016] The nonwoven material to be deep-drawn preferably has a density between 10 kg / m 3 and 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 cannot absorb significant tensile forces without tearing and cannot yet 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 2 , exposed to high temperatures. A constant or homogeneous surface pressure results in a constant or homogeneous material density of the preform, especially in the case of a homogeneous nonwoven material. To improve stability, the preform is pressed 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 for a preform with a constant or homogeneous material density. The mold can be used as packaging or further processed into packaging.

[0017] 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.The inner contour can also have at least one straight section in order to form a straight wall section of the preform.

[0018] The drawing punch has a forming section that is at least fundamentally configured to correspond to the die section and has a curved outer contour in a plane perpendicular to the drawing direction, at least in sections and corresponding to the die section. Furthermore, 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, opposite to the drawing direction. In other regions of the outer contour, in particular in non-curved regions of the outer contour, a tapered design of the drawing punch can be dispensed with.

[0019] 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 creating 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.

[0020] 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.

[0021] 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.

[0022] This principle applies to every curved wall section of the preform, in contrast to any straight wall section. In the latter case, 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.

[0023] The previously discussed accumulation of material in at least one curved wall section of the preform can be used during pressing of the preform to transform the preform into a conical compression mold or packaging without the preform tearing during pressing. The preform is stretched at least in sections during pressing. However, this does not lead to tearing of the preform or compression mold, since the material required for the stretching is provided by the increasing wall thickness previously provided by material accumulation in at least one curved wall section. This is all the more true since the preform is increasingly widened during pressing 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, fiber fleece material is initially accumulated in the at least one curved wall section so that this wall section can be stretched again during pressing, and thus pulled apart. This at least partially reverses the material accumulation. Since the fiber fleece material of the preform has only been pressed to a limited extent, the fiber fleece material of the preform is still sufficiently formable, in particular stretchable, during pressing. The forming device for forming the preform can have a die with a die section which has an inner contour extending at least substantially parallel to the drawing direction and which is curved at least in sections 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 that is curved at least in sections in a plane perpendicular to the drawing direction and corresponding to the die section and that tapers, preferably continuously, against the drawing direction.

[0024] By tapering the forming section of the drawing punch, more and more material can be absorbed into the gap between the die section and the forming section in the intake area of ​​the nonwoven material as the drawing punch is increasingly inserted into the die section. As the distance from the base of the preform increases, i.e., as the drawing depth increases, the gap between the die section and the forming section allows for an increasing wall thickness of the preform to be formed and for the absorption of more and more 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. In the area of ​​any straight wall section of the preform, a tapered mold section is not required, as no material accumulation is to be expected there. 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 .

[0025] With regard to the preform, the nonwoven material can be folded circumferentially around the central longitudinal axis of the preform in the at least one curved wall section of the preform, thus forming folds in the nonwoven material. For the reasons described above, the at least one curved wall section of the preform is increasingly folded from the base region toward the opening of the preform, whereby correspondingly more material is accumulated. The increase in wall thickness is preferably designed to correspond to the folding of the nonwoven material or at least to be continuous, in particular with a constant gradient.By folding the preform in at least one curved wall region, the nonwoven 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.

[0026] The preform can be formed with an outer contour oriented at least substantially parallel to the drawing direction, for which purpose the die section can have an inner contour oriented at least substantially parallel to the drawing direction, both to form a curved wall section and to form a straight wall section. The drawing punch can then form a preform with an inner contour inclined by at least 0.3°, preferably at least 1°, in particular at least 2°, and 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, in at least one curved wall section. As a result, 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.In this way, a material density of the preform that is at least essentially constant in the drawing direction can be provided.

[0027] 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. A varying wall thickness is not necessary in the straight wall section and is also not particularly desirable for surface pressure. The essentially constant surface pressure or material density of the nonwoven fiber material in the curved wall section of the preform then preferably corresponds to the surface pressure or material density of the nonwoven fiber material in the straight wall section of the preform. The at least one straight wall section of the preform can therefore be particularly expediently manufactured with an inner contour of the preform that extends at least substantially parallel to the drawing direction and an outer contour of the preform that extends at least substantially parallel to the drawing direction.The die section and the mold section are designed according to the inner contour and the outer contour.

[0028] During deep drawing between the drawing punch and the die, at least the mold section and / or the die section is preferably heated to a temperature between 40°C and 160°C, in particular between 50°C and 140°C, in order to avoid tearing of the nonwoven material during forming.

[0029] If the nonwoven material is folded during drawing into the at least one curved wall section of the preform, a wall thickness that increases, preferably continuously, in particular with a constant gradient, can be provided in the at least one curved wall section. As the drawing depth of the preform increases, the nonwoven material in the curved wall section is folded more and more.

[0030] In a 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. In this case, only a limited stretching is required during subsequent pressing, which can easily be provided by stretching, in particular by at least partially unfolding, the at least one curved wall section.

[0031] To demold the deep-drawn preform, it is advisable to pull the drawing punch out of the die together with the preform after the preform has been formed, and to pull the preform down from the drawing punch, expanding the preform at least in at least one curved wall section. Independently of this, the drawing punch can taper 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°, and more particularly at least 3°, relative to the drawing direction, in order to enable the desired drawing gap geometry as well as the at least substantially constant surface pressure and, if necessary, at least substantially constant material density of the preform.In order to form a straight wall section in the corresponding region of the forming section, the drawing punch can, if required, have an outer contour aligned at least substantially parallel to the drawing direction and / or to the die section.

[0032] 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.

[0033] Alternatively or additionally, a hold-down device can be provided in the area of ​​the edge section of the die for the purpose of defined forming. This hold-down device gently presses the flat nonwoven material against the edge section of the die before it is drawn into the drawing gap. For the same reason, a counter-holder can be provided adjacent to the free end of the drawing punch. This counter-holder is brought closer to the nonwoven material on the other side of the drawing punch and gently presses the nonwoven material against the free end of the drawing punch in the area of ​​the base of the preform, i.e., at the free end of the drawing punch, during the deep drawing of the preform.

[0034] 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, any straight wall section 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 these sections, the nonwoven fiber material is not folded or not folded to a significant extent and is therefore not folded or not folded to a significant extent. 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.For the reasons stated above, the preforms can have a draw ratio of greater than 0.3, preferably greater than 0.5, in particular greater than 0.75, and furthermore in particular greater than 1.0. The draw ratio corresponds to the ratio of the height of the preform to its minimum external width. For preforms with a circular base region, the draw ratio therefore corresponds to the ratio of the height of the preform to its external diameter. From corresponding preforms, compression molds can then be produced with depth ratios of the depth of the compression mold to its minimum external width, which are typically somewhat lower than the draw ratios of the preforms, but can also be greater than 0.3, preferably greater than 0.5, in particular greater than 0.75, and furthermore in particular greater than 1.0.

[0035] According to the method, the compression mold is formed from a preform with a wall thickness of at least one curved wall section which increases, preferably continuously, from the base region towards the opening of the preform. In the at least one curved wall section, there is therefore sufficient material present to enable expansion of the preform during pressing into a conical compression mold without the preform or compression mold tearing. For this purpose, the preform is introduced into a mold of a press with a conical inner contour and pressed therein with a conical press punch, reducing the wall thickness and widening the preform in at least one curved wall section, in such a way that at least in the corresponding curved wall section of the compression mold, the wall thickness increases from the base region towards the opening of the compression mold.

[0036] The additional accumulation of nonwoven material provided by the preform in at least one curved wall section is therefore preferably not fully utilized to stretch the preform into the compression mold, which counteracts tears in the nonwoven material. Furthermore, the at least one curved wall section of the compression mold is not pressed so strongly that a uniform wall thickness is created against the compression direction of the compression ram, as is known from other compression molds or packaging.Rather, by pressing the at least one curved wall section with a wall thickness that increases from the base region to the opening of the mold, it is possible to press the curved wall section with a relatively uniform, in particular at least substantially constant, surface pressure, in order to thereby provide a relatively uniform, in particular at least substantially constant, material density in the at least one curved wall section. This leads to preferred mechanical properties of the mold, reduces the risk of cracks, and can be implemented simply in terms of the process. The surface pressure during pressing can preferably be between 15 N / mm. 2 and 250 N / mm 2 be.

[0037] This is achieved by the fact that the inner contour of the mold in at least one pressing section curved around the pressing direction is more inclined than the corresponding outer contour of the press ram in the at least one pressing section curved around the pressing direction. A specific pressing force of the press ram can then be transferred relatively evenly to the press mold, at least in the at least one curved wall section, in order to produce a uniform material density of the press mold there with a uniform surface pressure. The surface pressure during pressing can preferably be between 15 N / mm 2 and 250 N / mm 2 be.

[0038] It is therefore possible to obtain a mold whose wall thickness increases, preferably continuously, in at least one curved wall section, starting from the base region of the mold in the direction of the opening of the mold. A uniform, in particular at least substantially constant, material density provided in this at least one curved wall section results in preferred mechanical properties of the mold. Otherwise, excessive material densities could occur in places, leading to undesirable brittleness, and / or insufficient material densities and thus to undesirably low rigidity of the mold. In a first particularly preferred embodiment of the method, a preform with at least one curved wall section is used to form the mold, in which the fiber fleece material is folded in the circumferential direction around the central longitudinal axis of the preform.The degree of folding and thus the degree of material accumulation in this region preferably increases from the base region of the preform toward the preform opening, in particular continuously, and more particularly at least substantially uniformly. For the sake of improved further processing, the wall thickness in at least one curved wall section can preferably increase from the base region toward the preform opening in a manner corresponding to the folding of the nonwoven material or at least substantially continuously.

[0039] In the case of at least one folded, curved wall section, it is advisable for the corresponding folds of the preform in the at least one curved wall section to be at least partially pulled apart during the forming of the preform into the compression mold. Thus, nonwoven material is provided from the preform for expanding the preform into the compression mold. It is irrelevant whether at least one curved wall section of the preform is formed into a corresponding curved wall section of the compression mold and / or whether at least one straight wall section of the preform is formed into a corresponding straight wall section of the compression mold.

[0040] Alternatively or additionally, to provide suitable molds, it is expedient if at least the at least one curved wall section of the mold is pressed at least substantially with an outer contour that is inclined more sharply relative to a central longitudinal axis of the mold than the corresponding inner contour. This difference in the inclinations of the outer contour and inner contour of the mold in the at least one curved wall section can easily ensure that the mold can be formed in the at least one wall section with a uniform, in particular at least substantially constant, material density even without a constant distribution of the nonwoven material.

[0041] For the sake of simplicity and to achieve suitable mechanical properties, the at least one straight wall section of the preform can be formed and pressed into a straight wall section of the compression mold. The straight wall section can preferably be inclined outwards so that the preform is widened, particularly in the region of the opening, during forming and pressing. Furthermore, the straight wall section of the preform and / or the compression mold has an at least substantially constant wall thickness, if necessary from the base region towards the opening and / or in the circumferential direction. For the reasons stated, it is further preferred if the at least one straight wall section of the compression mold is pressed with an outer contour inclined relative to a central longitudinal axis of the compression mold in a manner that at least substantially corresponds to the inclination of the inner contour of the at least one straight wall section of the compression mold.In a particularly simple case, the inner contour and the outer contour of at least one straight wall section of the mold are inclined to the same extent, i.e. at the same angle, to the central longitudinal axis of the mold.

[0042] In order to be able to provide a lid, for example, and / or to stiffen the mold, it may be advisable to press a preform into the mold with an edge region adjacent to the ends of the at least one curved wall section and / or the at least one straight wall section of the side wall that are opposite the base region. The advantages of the edge region become particularly apparent when the edge region is provided to be at least substantially circumferential. The same applies if the edge region of the preform adjacent to the at least one curved wall section is pressed into an edge section of the mold adjacent to the at least one curved wall section of the mold and / or the edge region of the preform adjacent to the at least one straight wall section is pressed into an edge section of the mold adjacent to the at least one straight wall section of the mold.

[0043] In order to simplify the process and provide compression molds with suitable mechanical properties, the edge region adjacent to the at least one curved wall section can also be pressed with a greater wall thickness than the edge region adjacent to the at least one straight wall section of the compression mold. In many cases, it will be expedient if the wall thickness of the edge region of the compression mold adjacent to the curved wall section is at least twice, in particular at least three times, as great as the wall thickness of the edge region adjacent to the straight wall section of the compression mold. In this way, account is taken of the fact that the nonwoven material has preferably been folded in the edge region adjacent to the at least one curved wall section during formation of the preform, whereas this does not occur during formation of the at least one straight wall section of the preform.In the edge region adjacent to the at least one curved wall section, there is therefore excess nonwoven material compared to the edge region adjacent to the at least one straight wall section. By providing different wall thicknesses in this region, a uniform, in particular at least substantially constant, surface pressure and an at least substantially uniform, in particular at least substantially constant, material thickness can be provided throughout the entire edge region. This simplifies the process and leads to preferred material properties of the mold. The surface pressure during pressing can preferably be between 15 N / mm. 2 and 250 N / mm 2 be.

[0044] To achieve suitable mechanical properties of the press mold, it is generally advisable if at least two of a list of at least one curved wall section, at least one straight wall section, the base region and the edge region of the press mold are pressed with an at least substantially constant surface pressure. The more sub-regions from the corresponding list this applies to, the more suitable mechanical properties of the press mold can generally be achieved. To achieve suitable mechanical properties of the press mold, it is additionally or alternatively advisable if the at least one curved wall section, the at least one straight wall section, the base region and / or the edge region of the press mold are each pressed with at least substantially the same, in particular at least substantially constant, material density. In this way, sufficient stability and sufficient ductility can be provided everywhere.The surface pressure during pressing can preferably be between 15 N / mm. 2 and 250 N / mm 2 be.

[0045] To ensure sufficient formability of the preform or mold during forming and pressing, it is recommended that the press mold and / or the press ram be heated to a temperature between 100°C and 200°C, particularly between 120°C and 160°C, during the preform pressing process. This allows the fibers of the nonwoven material to slide against each other without excessive resistance, and the nonwoven material retains its properties, particularly its optical properties. Regardless, it saves space and is easy to handle if the pressed molds are stacked one inside the other in at least one stack after removal from the press.

[0046] In a first particularly preferred embodiment of the pressing device, the inner contour of the mold in at least one pressing section of the mold curved around the pressing direction is inclined outwards by at least 0.5°, preferably at least 1°, in particular at least 2°, more strongly relative to the pressing direction of the press ram than the corresponding outer contour of the press ram in the corresponding curved pressing section. This will provide a press gap that widens towards the opening and takes into account the material accumulation of the nonwoven material provided in this direction in the preform. This enables pressing with at least uniform surface pressure to form a press mold with at least uniform material density in each of at least one curved wall sections of the press mold. The surface pressure during pressing can preferably be between 15 N / mm 2 and 250 N / mm 2 be.

[0047] In addition, it may be advisable if the inner contour of the mold is inclined in at least one straight pressing section of the mold that is not curved around the pressing direction at least substantially parallel to the corresponding outer contour of the press ram in at least one straight pressing section that is not curved around the pressing direction. The resulting press gap then has an at least approximately constant width, so that a preform formed in this region as a single layer with respect to the nonwoven material can be pressed with a uniform surface pressure to form a uniform material density of the press mold in the corresponding region. The surface pressure during pressing can preferably be between 15 N / mm 2 and 250 N / mm 2 be.

[0048] In a first particularly preferred embodiment of the pressing mold, a folded nonwoven material is provided in the at least one curved wall section of the pressing mold in the circumferential direction around the central longitudinal axis. This can preferably be the remnants of the folded, curved wall section of the preform, i.e. the folds that remain in the pressing mold when the preform has been stretched in the region of the curved wall section during forming and pressing. It is further preferred if the nonwoven material is increasingly folded from the bottom region towards the opening of the pressing mold. This leads to preferred material properties and avoids stress peaks in the pressing mold. This applies in particular if an increasing wall thickness is realized in the at least one curved wall section of the pressing mold from the bottom region towards the opening of the pressing mold, which increases correspondingly as the fibrous nonwoven material is folded.The more tightly the nonwoven material is folded in the curved wall section, the more fiber material accumulates there. To ensure uniform surface pressure and material density in at least one curved wall section, the wall thickness increases in proportion to the folding or material accumulation.

[0049] The side wall can also have at least one straight wall section that is not curved around a central longitudinal axis of the mold in order to provide correspondingly shaped molds in the sense of a packaging. The wall thickness of the at least one straight wall section of the side wall of the mold can preferably be at least substantially constant from the bottom region towards the opening of the mold. In particular, when using a preform with a single-layer nonwoven fiber material in the corresponding straight wall section, an at least substantially constant wall thickness in the at least one straight wall section of the mold can ensure a homogeneous, in particular at least substantially constant, material density.

[0050] In order to be able to provide a lid easily or to stiffen the mold, an edge region can be provided at the ends of the at least one curved wall section and / or the at least one straight wall section adjacent to the side wall, which ends are opposite the base region, and which border the at least one curved wall section and / or the at least one straight wall section. These advantages are particularly evident when the edge region is provided at least substantially circumferentially to the opening of the mold. If, in addition, the edge region adjacent to the at least one curved wall section has a greater wall thickness than the edge region adjacent to the straight wall section, a strong folding of the edge region adjacent to the curved wall section compared to the edge region adjacent to the straight wall section can be taken into account.This allows for simple and efficient pressing of the preform into the mold, particularly while providing a uniform, preferably at least substantially constant, material density in the edge region. It is also advantageous if the wall thickness of the edge region adjacent to the curved wall section is at least twice as large, in particular at least three times as large, as the wall thickness adjacent to the at least one straight wall section.

[0051] The invention is explained in more detail below with reference to a drawing which merely illustrates exemplary embodiments. The drawing shows

[0052] Fig. 1 shows a forming device according to the invention in a schematic side view,

[0053] Fig. 2A-B preforms according to the invention with a round bottom and an approximately rectangular bottom in a perspective view,

[0054] Fig. 3A-C steps of a method according to the invention for producing a preform in a schematic sectional view,

[0055] Fig. 4A-B a preform according to the invention in different states in a sectional view and

[0056] Fig. 5 a detail of the preform from Fig. 2B in a view from above,

[0057] 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,

[0058] Fig. 7A-B the pressing of a preform according to the invention in a pressing device according to the invention as well as a pressing mold according to the invention in schematic sectional views along a sectional plane through a curved wall section, Fig. 8A-B the pressing of a preform according to the invention in a pressing device according to the invention as well as a pressing mold according to the invention in schematic sectional views along a sectional plane through a straight wall section,

[0059] Fig. 9A-B compression molds according to the invention produced from the preforms according to Fig. 2A-B in perspective views.

[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 pulled off the drawing punches 12 and placed in a pressing station 13 into a mold 14 of a press 15, 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.In order to improve the formability of the nonwoven material, the drawing punch 12 and / or the die 11 are heated to a temperature between 40°C and 160°C, while the pressing punch 16 and the mold 14 are heated to a temperature between 100°C and 200°C.

[0061] Since the step of preforming the blanks 9 from nonwoven material 3 takes longer than the other process steps, the cutting station 6, pressing station 13, punching station 17 and stacking station 18 are operated in a cycle that is half as long as the cycle of the deep-drawing station 10. Thus, in the process shown, 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 preform 2 having 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 formed by a single, completely circumferential, curved wall section 25. The preform 2 is deep-drawn from a flat blank 9 of a nonwoven fiber material 3. Starting from the region of the nonwoven fiber 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 fiber 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 the 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, and this is all the more true for rings located further out than for rings of the nonwoven fiber material located further in. 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, if necessary continuously and with a constant gradient. The folding of the nonwoven fiber material 3 during deep drawing of the preform 2 is illustrated by the lines in the edge region that extend towards the opening 23 of the preform 2.The folds TI of the nonwoven material 3 of the side wall 22 are illustrated by the lines extending from the opening 23 towards 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., the further it is deep-drawn, the more fiber fleece material 3 is drawn into the curved wall sections 32.

[0064] The situation is different for 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 essentially constant, while the wall thickness in the curved wall sections 32 increases continuously and with a constant gradient from the base region 29 to the edge region 34. This is the result of the folds 27 formed by the nonwoven fiber material 3 in the curved wall sections 32. The folds already form in the adjacent parts of the edge region 34. In the straight wall sections 33, the nonwoven fiber material 3 is not folded any more than in the adjoining sections of the edge region 34. In Fig.3A-C illustrates 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.

[0065] Then, according to Fig. 3B, the drawing punch 12, together with the counterholder 36, is moved in the drawing direction Z indicated by the arrow into a die section 39 of the die 11, which, together with a drawing section 40 at the free end of the drawing punch 12, forms a drawing gap 41, via which the nonwoven material 3 is increasingly drawn into the drawing gap 42 between a forming section 43 of the drawing punch 12, which can be provided directly adjacent to the drawing section 40, and the die section 39. A rounded transition region 44 with an at least substantially identical radius all around is also provided between the die section 39 and the edge section 38 of the die 11. In the forming section 43, the drawing punch 12 is provided with an outer contour that tapers at least in sections, counter to the drawing direction Z, which outer contour in this case is provided with a constant inclination a to the drawing direction Z.The inner contour of the die section 39 is aligned parallel to the drawing direction, wherein the die section 39 and the mold section 43 are curved in the circumferential direction.

[0066] According to Fig. 3C, the drawing gap 42 widens between the mold section 43 and the

[0067] Die section 39 increases towards the upper edge of the die section 39, and the greater the drawing depth T of the preform 28 is. With the deep drawing, more and more nonwoven material 3 can be taken up in the drawing gap 42 and pressed with an at least substantially constant surface pressure. The surface pressure of the nonwoven material 3 can, for example, be between 6 N / mm 2 and 22 N / mm 2 be.

[0068] 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. The preform 28 has an outer contour which, like the inner contour of the die section 39, extends parallel to the drawing direction Z. The bottom region 29 of the preform 28 is aligned at least substantially at a right angle to the outer contour in the at least one curved wall section 32. The inner contour of the preform 28 is inclined upwards towards the opening 35 of the preform 28 in the illustrated at least one curved wall section 32, specifically counter to the drawing direction Z or a central longitudinal axis L, continuously and inwardly with a constant gradient a, which can be, for example, at least 0.3°, preferably at least 1°.Roundings of the preform 28 at the transition between the base area 29 and the side wall 31 as well as between the side wall 31 and the edge area 34 are not shown for the sake of clarity.

[0069] When the preform 28 is pulled off the drawing punch 12, the preform 28 is widened in the region of the at least one curved wall section 32, after which the preform 28 can assume the shape shown in Fig. 4B in the at least one curved wall section 32. The inner contour of the preform 28 is then aligned in the at least one curved wall section 32 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 widens counter to the drawing direction Z or a central longitudinal axis L by an angle α corresponding to the aforementioned gradient. Rounded portions of the preform 28 have also been omitted here. Fig. 5 shows a detail of the preform 28 from Fig. 2B in a view from above, wherein the detail comprises a curved wall section 32 and a straight wall section 33.Shown are the associated edge regions 34 of the preform 28 and the bottom region 29 with a straight edge 45 and a rounded corner 30. The deep drawing of the straight wall section 33 and the curved wall section 32 of the preform 28 is shown in Fig. 6A-B, wherein the preform 28 is shown in sectional views corresponding to the section planes VIA-VIA and VIB-VIB of Fig. 5.

[0070] According to Fig. 6A, the drawing punch 12 has been retracted 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. The nonwoven material 3 is lightly pressed against the free end of the drawing punch 12 by a counter-holder 36, while the drawing punch 12 is retracted further in the drawing direction Z into the die section 39. In the region shown, the die section 39 has an inner contour that extends parallel to the drawing direction Z and perpendicular to the upper side of the edge section 38 of the die 11 and to the free end of the drawing punch 12. 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, so that the drawing gap 42 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 and is there with a uniform surface pressure, approximately between 10 N / mm. 2 and 15 N / mm 2, pre-compacted. The nonwoven material 3 has a uniform material density in the straight wall section 33 of the preform 28. 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 base region 29, wherein the base region 29 and the straight wall section 33 have a constant and identical wall thickness d2=d3. 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, 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 is inclined in a direction opposite to the drawing direction Z by a constant angle a relative to the drawing direction Z, so that the drawing gap 42 becomes wider opposite to the drawing direction Z with a corresponding constant gradient a.

[0071] The nonwoven material 3 folds before being drawn into the drawing gap 42, and the deeper the drawing punch 12 is inserted into the die 11, the more it folds. The increase in the width of the drawing gap 42 corresponds to the increase in the nonwoven material 3 to be drawn in and its folding, so that the surface pressure of the nonwoven material 3 in the curved wall section 32 in the drawing direction Z is at least essentially constant and also at least essentially corresponds to the surface pressure of the 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 essentially constant and at least essentially corresponds to the material density in the straight wall section 33 and in the base region 29. The wall thickness orThickness dl of the nonwoven fiber material 3 in the edge region 34 of the preform 28 is at least approximately equal to the wall thickness d2 of the nonwoven fiber material 3 at the upper end of the drawing gap 42. However, the wall thicknesses dl, d2 of the preform 28 are greater at both points than the wall thicknesses d3, d4 at the lower end of the drawing gap and the bottom region 29, the latter wall thicknesses d3, d4 being at least approximately equal to one another.

[0072] Fig. 7A shows the pressing of a preform 2, 28 in the region of a curved wall section 25, 32 in a press 15 of a pressing device 46. A schematic section without roundings through a correspondingly manufactured, curved wall section 47, 48 of a side wall 62 of a pressing mold 49, 50 is also shown in Fig. 7B. To press and form the preform 2, 28, it is placed in a mold 14 of the press 15, into which a pressing ram 16 is subsequently inserted in the pressing direction P. As the pressing ram 16 is inserted into the mold 14, the curved wall section 25, 32 of the preform 2, 28 is deformed in such a way that the curved wall section 25, 32 is inclined outwards in order to produce a conical, stackable shape of the pressing mold 49, 50. The curved wall section 47,48, like the mold 14 and the press ram 16, is at least partially curved around a central longitudinal axis A of the press mold 49,50 orcurved around the pressing direction P. In a plane perpendicular to the central longitudinal axis A or the pressing direction P, the curvature of the curved wall section 47, 48 and the curved pressing sections 65, 66 of the mold 14 and press ram 16 can be constant. However, the radius increases with the distance of the corresponding plane from the base region 51, 52 of the pressing mold 49, 50.

[0073] The bottom area 51,52 of the press mold 49,50 is not widened, but merely pressed further, so that the wall thickness sl of the bottom area 51,52 of the press mold 49,50 is less than the wall thickness d3 of the bottom area 21,29 of the preform 2,28. The outer contour of the press ram 16 in the region of the curved wall section 47,48 of the press mold 49,50 tapers in the direction of the free end of the press ram 16, thus in the pressing direction P. Likewise, the inner contour of the mold 14 tapers in the region of the curved wall section 47,48 of the press ram 16 in the pressing direction P, thus in the direction of the bottom 53 of the mold 14. In the illustrated embodiment, the inner contour of the mold 14 and the outer contour of the press ram 16 in the curved pressing sections 64,65 adjacent to the curved wall section 47,48 of the press mold 49,50 are inclined at a constant but different angle ß,y.The inclination of the mold 14 in the conical region is greater than the inclination of the press ram 16 in the conical region, so that a press gap 54 is provided that widens with increasing distance from the base region 51, 52. As a result, a press mold 49, 50 is formed with a wall thickness s2 that increases in the curved wall section 47, 48 from the base region 51, 52 towards the opening 55, 56, wherein the curved wall section 47, 48 is compacted between the base region 51, 52 and the opening 55, 56 with at least substantially constant surface pressure and is thereby formed with an at least substantially constant material density. This takes into account the fact that the nonwoven material of the curved wall section 47, 48 is still partially folded, with the degree of folding increasing from the base region 51, 52 towards the opening 55, 56.The folds 27 were formed during the deep drawing of the preform 2,28 and were only partially pulled apart again during the forming of the preform 2,28 into the press mold 49,50.

[0074] The edge region 57,58 adjacent to the curved wall section 47,48 is also pressed between the press ram 16 and the mold 14 in the pressing direction P, specifically between edge sections 59,60 of the mold 14 and the press ram 16, which can extend at least substantially perpendicular to the pressing direction P. Folds 27 are also provided in the edge region 57,58 adjacent to the curved wall section 47,48. These folds were formed during the deep-drawing of the preform 2,28 and were not completely pulled apart again during the forming of the edge region 24,34 in the press 15. Consequently, more nonwoven material 3 is accumulated in the edge region 57,58 adjacent to the curved wall section 47,48 than in the base region 51,52, in which the nonwoven material 3 is provided in a single layer.The edge region 57, 58 there is pressed with a surface pressure that is at least substantially the same as that of the curved wall section 47, 48 and the base region 51, 52, so that in the edge region 57, 58 adjacent to the curved wall section 47, 48, a material density s3 is obtained that at least substantially corresponds to the material density s2 in the curved wall section 47, 48 and in the base region 51, 52. To enable this, the press gap 54 and thus the wall thickness s3 in the edge region 57, 58 adjacent to the curved wall section 47, 48 are larger than in the base region 51, 52 and approximately as large as at the upper edge of the curved wall section 47, 48. The aforementioned principles for pressing a curved wall section 47, 48 are independent of whether a straight wall section 61 of the side wall 62 of the mold 50 is also provided. In a straight wall section 61, according to Fig.8A also depicts a forming and pressing of the preform 28, which leads to a widening of the preform 28 in the straight wall section 61. The straight wall section 61 of the mold 50, which is shown in Fig. 8B in a schematic section without rounding, is increasingly pressed outwardly from the base region 52 toward the opening 56, so that a conical and therefore stackable mold 50 is produced. The material required for the corresponding forming of the straight wall section 61 is provided by the adjacent curved wall sections 48, whose folded nonwoven material 3 is partially unfolded in the press 15 for this purpose.

[0075] The outer contour of a straight pressing section 67 of the pressing ram 16 is inclined outwards in this region at a constant angle ö relative to the pressing direction P, so that the pressing ram 16 tapers in the direction of the free end 63. As a result of the pressing, the inner contour of the straight wall section 61 assumes the same angle ö relative to a central longitudinal axis A of the pressing mold 50 or pressing direction P of the pressing ram 16. The outer contour of the straight wall section 61 and the inner contour of a straight pressing section 68 of the mold 14 adjacent to the straight wall section 61 are also inclined outwards at the same angle ö relative to the central longitudinal axis A or the pressing direction P, starting from the base region 52 of the pressing mold 50 in the direction of the opening 56 of the pressing mold 50.In the region of the straight wall section 61, this results in a press gap 54 and a wall thickness s4 of the press mold 50 that has a constant width at least substantially from the bottom region 52 to the opening 56. The rounded portions of the press mold 50 adjacent to the bottom region 52 and the opening 56 are disregarded.

[0076] Wrinkling of the nonwoven material 3 occurs in the illustrated

[0077] This does not occur in the straight wall section 61 in the exemplary embodiment and can therefore be disregarded. The straight wall section 61 is pressed with an at least substantially constant surface pressure, which in particular corresponds at least substantially to the surface pressure of the remaining parts of the pressing mold 50. In the straight wall section 61 with a preferably single-layer nonwoven material 3, an at least constant material density is thus generated, which preferably corresponds at least substantially to the material density in the remaining parts of the pressing mold 50.

[0078] The edge region 64 adjacent to the straight wall section 61 is also pressed between the press ram 16 and the mold 14 in the pressing direction P, specifically between edge sections 59, 60 of the mold 14 and the press ram 16, which can extend at least substantially perpendicular to the pressing direction P. In this edge region 64, as well as in the base region 52 and in the straight wall section 61 of the press mold 50, the nonwoven material 3 is preferably provided in a single layer, i.e., not folded. Therefore, in the illustrated embodiment, the wall thickness s5 of the edge region 64 corresponds at least substantially to the wall thickness s4 of the straight wall section 61 and the wall thickness s1 of the base region 52. All of these sub-regions of the press mold 50 can be pressed with an at least substantially constant surface pressure and can therefore be formed with an at least substantially constant material density.The surface pressure when pressing all or some of these sub-areas can preferably be between 15 N / mm. 2 and 250 N / mm 2 be.

[0079] Fig. 9A shows a mold 49 with a single wall section 47 that is uniformly curved around a central longitudinal axis A of the mold 49 and with an edge 45 that is uniformly curved around the central longitudinal axis A of the mold 49, as well as a mold 50 with two curved wall sections 48 and two straight wall sections 61 provided between them. The mold 49 with a circular base region 51 is uniformly, if not at least substantially rotationally symmetrical, around the central longitudinal direction A of the mold 49. According to Fig. 9B, the mold 50 with straight wall sections 61 and curved wall regions 48 has an edge region 58 whose wall thickness s3 adjacent to the curved wall sections 48 is at least twice as large as the wall thickness s5 of the edge region 64 adjacent to the straight wall sections 61. The edge regions 58, 64 together form a circumferential edge 45.

[0080] List of reference symbols

[0081] 1 forming device 48 curved wall section

[0082] 2 Preform 49 Press mold

[0083] 3 nonwoven material 50 press mold

[0084] 4 Press mold 51 bottom area

[0085] 5 Roll 52 Floor area

[0086] 6 Cutting station 53 Floor

[0087] 7 circulation 54 press gap

[0088] 8 cutting edge 55 opening

[0089] 9 Cutting 56 Opening

[0090] 10 Deep drawing station 57 Edge area

[0091] 11 Die 58 Edge area

[0092] 12 drawing punches 59 edge section

[0093] 13 Pressing station 60 edge section

[0094] 14 Form 61 straight wall section

[0095] 15 Press 62 Sidewall

[0096] 16 press ram 63 free end

[0097] 17 punching station 64 edge area

[0098] 18 Stacking station 65 curved pressing section

[0099] 19 stack 66 curved press section

[0100] 20 benefits 67 straight pressing section

[0101] 21 floor area 68 straight pressing section

[0102] 22 Sidewall a Gradient / Angle

[0103] 23 Aperture ß Gradient / Angle

[0104] 24 Edge area y gradient / angle

[0105] 25 curved wall section ö gradient / angle

[0106] 27 folds A central longitudinal axis

[0107] 28 Preform d Wall thickness / Thickness

[0108] 29 Floor area L central longitudinal axis

[0109] 30 Corner s Wall thickness / Thickness

[0110] 31 Side wall T Drawing depth

[0111] 32 curved wall section Z drawing direction

[0112] 33 straight wall section P pressing direction

[0113] 34 Marginal area

[0114] 35 Opening

[0115] 36 counterholders

[0116] 37 hold-down clamps

[0117] 38 edge section

[0118] 39 Die section

[0119] 40 drawing section

[0120] 41.42 drawing gap

[0121] 43 mold section

[0122] 44 Transition area

[0123] 45 Rand

[0124] 46 Pressing device

[0125] 47 curved wall section

Claims

Patent claims 1. A method for producing a press mold (49, 50) for use as packaging or further processing into a packaging from a preform (2, 28) formed at least substantially from a nonwoven material (3) 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), wherein the wall thickness (d2,d4) of the at least one curved wall section (25,32) of the side wall (22,31) of the preform (2,28) in the at least one curved wall section (25,32) from the base region (21.29) increases, preferably continuously, in the direction of the opening (23,35) of the preform (2,28), in which the preform (2,28) is introduced into a mold (14) of a press (15) with a conical inner contour and is pressed in the mold (14) with a conical press punch (16) while reducing the wall thickness (dl-d4) of the preform (2,28) and widening the preform (2,28) at least in at least one curved wall section (25,32), and in which, during the pressing of the preform (2,28), at least one curved wall section (47) of the pressing mold (49,50) is formed with a wall thickness (s2) increasing from the base region (51,52) in the direction of the opening (55,56).

2. Method according to claim 1, wherein the preform (2,28) used is a preform (2,28) with fibrous nonwoven material (3) increasingly folded in the at least one curved wall section (25,32) in the circumferential direction around 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 / or in which a preform (2,28) with a wall thickness (d2,d4) increasing in the at least one curved wall section (25,32) from the base region (21,29) in the direction of the opening (23,35) of the preform (2,28), preferably corresponding to the folding of the nonwoven material (3) or at least substantially continuously, is used as the preform (2,28).

3. Method according to claim 2, in which folds (27) of the preform (2, 28) in the at least one curved wall section (25, 32) are at least partially pulled apart during the forming of the at least one curved wall section (25, 32) of the preform (2, 28) into at least one curved wall section (47, 48) of the pressing mold (49, 50) and / or in which folds (27) of the preform (28) in the at least one curved wall section (32) are at least partially pulled apart during the forming of the at least one straight wall section (33) of the preform (28) into at least one straight wall section (61) of the pressing mold (50).

4. Method according to one of claims 1 to 3, in which the at least one curved wall section (47, 48) of the pressing mold (49, 50) is pressed at least substantially with an outer contour which is inclined more strongly than the corresponding inner contour with respect to a central longitudinal axis (A) of the pressing mold.

5. Method according to one of claims 1 to 4, in which at least one straight wall section (33) of the preform (28), in particular with a wall thickness (d2) that is at least substantially constant from the base region (29) in the direction of the opening (35), is pressed into a straight wall section (61) of the press mold (50), in particular with a wall thickness (s4) that is at least substantially constant from the base region (52) in the direction of the opening (56), and in which, preferably, the at least one straight wall section (61) of the pressing mold (50) is pressed at least substantially with an outer contour which is inclined to the same extent as the corresponding inner contour with respect to a central longitudinal axis (A) of the pressing mold (50).

6. Method according to one of claims 1 to 5, wherein the preform (2, 28) used is a preform (2, 28) having a preferably at least substantially circumferential edge region (24, 34) adjacent to the ends of the at least one curved wall section (25, 32) and / or the at least one straight wall section (33) of the side wall (22, 31) opposite the base region (21, 29), wherein the edge region (24, 34) of the preform (2, 28) adjacent to the at least one curved wall section (25, 32) is connected to an edge region (57, 58) of the pressing mold (49, 50) adjacent to the at least one curved wall section (47, 48) of the pressing mold (49, 50) and / or the edge region (34) of the preform (28) adjacent to the at least one straight wall section (33) is connected to an edge section (64) of the pressing mold (50) is pressed adjacent to the at least one straight wall section (61) of the pressing mold (50) and in which, further preferably,the edge region (58) adjacent to the at least one curved wall section (48) is pressed with a greater, preferably at least twice as large, in particular at least three times as large, wall thickness (s5) than the wall thickness (s5) of the edge region (64) adjacent to the at least one straight wall section (61) of the mold (50)., 7. Method according to one of claims 1 to 6, wherein the at least one curved wall section (47, 48) of the pressing mold (49, 50) and / or the at least one straight wall section (61) of the pressing mold (50) and / or the bottom region (51, 52) of the pressing mold (49, 50) and / or the edge region (57, 58, 64) of the pressing mold (49, 50) is provided with a Essentially constant surface pressure, preferably between 15 N / mm 2 and 250 N / mm 2, is pressed and / or in which the at least one curved wall section (47,48) of the pressing mold (49,50) and / or the at least one straight wall section (61) of the pressing mold (50) and / or the bottom region (51,52) of the pressing mold (49,50) and / or the edge region (57,58,64) of the pressing mold (49,50) are pressed with at least substantially the same material density.

8. Method according to one of claims 1 to 7, in which the mold (14) of the press (15) and / or the press ram (16) is heated to a temperature between 100°C and 200°C, in particular between 120°C and 160°C, during the pressing of the preform (2, 28) and / or in which the pressed molds (49, 50) are stacked one inside the other in at least one stack (19).

9. Pressing device (46) for producing a press mold (49, 50) for use as packaging or further processing into packaging, preferably by means of the method according to one of claims 1 to 8, with a press (15) comprising a mold (14) and a press ram (16) designed to correspond to the mold (14) and retractable into the mold (14) in a pressing direction (P), wherein the mold (14) has an inner contour extending at least substantially conically from a base (53) to an opening of the mold (14) and the press ram (16) has an outer contour extending at least substantially conically in the direction of the free end (63) of the press ram (16) for forming nestable press molds (49, 50), characterized in thatthat the inner contour of the mold (14) in at least one pressing section (65) of the mold curved around the pressing direction (P) is more inclined than the corresponding outer contour of the press punch (16) in at least one pressing section (66) curved around the pressing direction (P).

10. Pressing device according to claim 9, characterized in that the inner contour of the mold (14) in at least one pressing section (65) of the mold (14) curved around the pressing direction (P) is inclined by at least 0.5°, preferably at least 1°, in particular at least 2°, more strongly than the corresponding outer contour of the press ram (16) in at least one pressing section (66) curved around the pressing direction (P).

11. Pressing device according to claim 9 or 10, characterized in that the inner contour of the mold (14) in at least one straight pressing section (68) of the mold (14) which is not curved around the pressing direction (P) is inclined at least substantially parallel to the corresponding outer contour of the press ram (16) in at least one straight pressing section (67) which is not curved around the pressing direction (P).

12. Press mold (49, 50) for use as packaging or further processing into packaging, preferably produced by a method according to one of claims 1 to 8 and / or by means of a pressing device (46) according to one of claims 9 to 11, at least substantially from a nonwoven material (3), with an opening (55, 56), a side wall (62) and a bottom region (51, 52), wherein the side wall (62) has at least one wall section (47, 48) curved about a central longitudinal axis (A) of the press mold (49, 50), characterized in that the wall thickness (s2) of the at least one curved wall section (47, 48) of the side wall (62) of the press mold (49, 50) in the at least one curved wall section (47, 48) from the bottom region (51, 52) in the direction of the opening (55, 56) of the press mold (49, 50), preferably continuously, increases.

13. Press mold according to claim 12, characterized in that in the at least one curved wall section (47, 48) of the press mold (49.50), in the circumferential direction around the central longitudinal axis (A), in particular from the bottom area (51,52) in the direction of the opening (55,56) of the mold (49,50) increasingly, folded nonwoven material (3) is provided and that, preferably, in the at least one curved wall section (47,48) of the pressing mold (49,50) a wall thickness (s2) increasing from the bottom region (51,52) in the direction of the opening (55,56) of the pressing mold (49,50) corresponding to the folding of the nonwoven material (3) is provided.

14. Press mold according to claim 12 or 13, characterized in that the side wall (62) has at least one straight wall section (61) which is not curved about a central longitudinal axis (A) of the press mold (50) and that, preferably, the wall thickness (s4) of the at least one straight wall section (61) of the side wall (62) of the press mold (50) from the bottom region (52) in the direction of the opening (56) of the press mold (50) is at least substantially constant.

15. Press mold according to one of claims 12 to 14, characterized in that at the ends of the at least one curved wall section (47, 48) and / or the at least one straight wall section (61) of the side wall (62) opposite the bottom region (51, 52), a preferably at least substantially circumferential edge region (57, 58, 64) is provided, which is adjacent to the at least one curved wall section (47, 48) and / or at least one straight wall section (61), and in that, preferably, the edge region (58) adjacent to the at least one curved wall section (48) has a greater, preferably at least twice as great, in particular at least three times as great, wall thickness (s3) than the wall thickness (s5) of the edge region (64) adjacent to the at least one straight wall section (61) of the side wall (62).

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