Method for manufacturing a preform and a package, a forming device and a preform

Abstract

The present invention relates to a method for manufacturing preforms (2, 28) from a planar fibrous nonwoven material (3) by deep drawing using a bottom die (11) and a drawing punch (12) movable into the bottom die (11) along the stretching direction, wherein the bottom die (11) has a bottom die section (39) having an inner contour extending parallel to the stretching direction (Z) and curved in a plane perpendicular to the stretching direction (Z), and wherein the drawing punch (12) has a forming section (43) having an outer contour partially curved in a plane perpendicular to the stretching direction (Z) and corresponding to the bottom die section (39), which tapers gradually at least against the stretching direction (Z), preferably continuously, wherein the fibrous nonwoven material (3) is arranged in the bottom die (11). Between the stretching punch (12) and the stretching punch (12), the stretching punch (12) is then moved into the bottom die section (39) along the stretching direction (Z), wherein, during the movement of the stretching punch (12) into the bottom die section (39), the fiber nonwoven material (3) is at least partially deep-drawn in the stretching gap (42) between the bottom die section (39) and the stretching section (40) of the stretching punch (12), wherein, during the movement of the stretching punch (12) into the bottom die section (39), a preform is formed between the bottom die section (39) and the forming section (43), the preform having curved wall sections (25, 32) in a plane perpendicular to the stretching direction (Z), and having a wall thickness (d2, d4) that preferably increases continuously against the stretching direction (Z) in the curved wall sections (25, 32).

Description

Technical Field

[0001] This invention relates to a method for manufacturing preforms from planar fibrous nonwoven materials by deep drawing for further processing into packaging. The invention also relates to a method for manufacturing stackable packaging using preforms formed from fibrous nonwoven materials. Furthermore, the invention relates to a forming apparatus for manufacturing preforms from planar fibrous nonwoven materials by deep drawing (the deep drawing is achieved using a bottom die and a drawing punch capable of moving into the bottom die along the stretching direction), and to a preform made of fibrous nonwoven material for further processing into packaging having an opening, sidewalls, and a bottom region, wherein the sidewalls have at least one curved section surrounding the central longitudinal axis of the preform. Background Technology

[0002] Plastic packaging can be manufactured in many different shapes depending on the application, for which thermoforming machines are used in many cases, in particular, to shape sheet-like plastic into three-dimensional packaging. However, the resulting plastic packaging enters the environment in large quantities, where, in most cases, it is not biodegradable and will therefore be mechanically pulverized into undesirable microplastics over time. To avoid this, higher costs are required for recycling and reusing plastic packaging.

[0003] In this context, reinforced packaging made from biodegradable, and especially renewable, fibers (such as paper or cardboard) can be coated as needed to provide sufficient moisture resistance and make it suitable for food packaging. However, the manufacture of such packaging is expensive and can only be produced in a limited number of shapes because fibrous materials are more difficult to mold than thermoplastics, in particular. This is especially true for packaging made from nonwoven fibrous materials (such as nonwoven fabrics made from cellulose fibers), which are therefore particularly eco-friendly.

[0004] To manufacture packages from planar fiber nonwoven materials (these packages are formed into a conical shape so that multiple packages can be stacked on top of each other), it is proposed that, in a forming apparatus, so-called preforms be first produced by deep drawing the fiber nonwoven material. These preforms approximate the shape of the desired package, and then these preforms are pressed into packages in their final shape. This is carried out in a single processing flow using appropriately forming drawing punches and pressing punches with corresponding dies.

[0005] Here, the packaging has a bottom area, an opening, and sidewalls disposed between the bottom area and the opening. Because the sidewalls are prone to breakage at their edges or corners, the sidewalls have at least one curved section surrounding the central longitudinal axis of the preform. Here, the curved portion can have a constant radius, which is arranged in a plane surrounding the central longitudinal axis of the preform. In cases where the shape of the packaging (i.e., a bucket with a circular bottom area) is particularly simple, the radius surrounding the central longitudinal axis of the preform is constant. However, for example, it is also possible to consider preforms with elliptical bottom areas, and preforms with bottom areas that partially have straight edges, from which packaging with an approximately rectangular bottom and rounded edges can be manufactured.

[0006] However, known methods can only reliably manufacture packages that are relatively flat in size. Therefore, such packaging cannot meet all requirements, so there is a need for packaging that is particularly deeper than the bottom base and allows for a variety of bottom shapes. Summary of the Invention

[0007] Therefore, the object of the present invention is to design and improve the methods, molding apparatus and preforms mentioned at the beginning and explained in detail above, so as to enable greater flexibility in packaging shaping.

[0008] The task, according to claim 1, is solved by a method for manufacturing preforms for further processing into packaging from a planar fibrous nonwoven material by deep drawing (which is achieved using a die and a drawing punch movable into the die along the stretching direction), wherein the die has a die section having an inner contour extending at least substantially parallel to the stretching direction and at least partially curved in a plane perpendicular to the stretching direction, and wherein the drawing punch has a forming section having an outer contour at least partially curved in a plane perpendicular to the stretching direction and corresponding to the die section, which at least partially tapers gradually against the stretching direction, preferably continuously. - In this process, nonwoven fiber material is arranged between the bottom die and the stretching punch, and then the stretching punch is moved into the bottom die section along the stretching direction. - During the period when the drawing punch moves into the bottom die section, the nonwoven fiber material is at least partially deep-drawn in the drawing gap between the bottom die section and the drawing section of the drawing punch. - During the period when the stretching punch moves into the bottom die section, a preform is formed between the bottom die section and the forming section. The preform has at least one curved wall section in a plane perpendicular to the stretching direction and a wall thickness that preferably increases continuously in the at least one curved wall section against the stretching direction.

[0009] Furthermore, the task described in claim 7 is achieved through a method for manufacturing stackable packaging from a preform made of a nonwoven fiber material. - wherein the preform is formed according to any one of claims 1 to 6. - In this process, the preform is placed into a die with a tapered inner profile in a press, and under the condition that the wall thickness of the preform is reduced, it is pressed in the die by a tapered pressing punch in at least one curved wall section, and - Preferably, the successively pressed packages are stacked on top of each other.

[0010] Furthermore, the aforementioned task is solved in the forming apparatus according to the preamble of claim 9 by the following manner: the bottom die has a bottom die section having an inner contour that extends at least substantially parallel to the stretching direction and is at least partially curved in a plane perpendicular to the stretching direction; and the stretching punch has a forming section having an outer contour that is at least partially curved in a plane parallel to the stretching direction and corresponding to the bottom die section, which at least partially tapers gradually against the stretching direction, preferably continuously.

[0011] The aforementioned task is also solved in the preform of the preamble according to claim 12 by the following manner: the nonwoven fiber material is increasingly folded from the bottom region of the preform toward the opening in at least one curved wall section in the circumferential direction around the central longitudinal axis of the preform, and the wall thickness of at least one curved wall section gradually increases from the bottom region of the preform toward the opening, preferably corresponding to the folds of the nonwoven fiber material, or at least substantially continuously increasing.

[0012] Nonwoven fiber materials are preferably manufactured using a method known as air-laid bonding. Here, fibers are layered together by airflow to form nonwoven tapes. These tapes form a loose nonwoven fabric, held in place by pressure or adhesives. The pressure refers only to a degree of compaction, allowing the resulting nonwoven fiber material to be sufficiently shaped for deep drawing. Cellulose, wood cellulose (obtained from lignin-containing wood), or other predominantly organic fibers such as flax or hemp are particularly considered as fiber materials. The fibers do not necessarily have to be organic, but recycled materials are generally preferred for ecological reasons. Synthetic fibers, such as those made from plastics, can also be used in conjunction with non-organic but renewable fibers. Adding additives that hydrophobize cellulose fibers, such as alkyl ketone dimers (AKD), can, for example, improve the moisture resistance of the produced packaging.

[0013] Preferably, the nonwoven fiber material to be deep-drawn has a density of 10 kg / m². 3Up to 200 kg / m 3 The density has been shown to be particularly preferred, with a density of 20 kg / m³. 3 and 350 kg / m 3 The nonwoven fiber material is used. The thickness of the fiber material is preferably between 1 mm and 20 mm, particularly between 2.5 mm and 6 mm. Therefore, this nonwoven fiber material is slightly compacted so that it cannot withstand significant tensile forces without tearing. This condition is taken into account in the method of manufacturing the preform. The nonwoven fiber material of the preform is also not so strongly compacted so that the preform can be used as packaging in the desired manner. During deep drawing, the preform is subjected to a surface pressure that is as constant as possible, preferably 6 N / mm². 2 and 22 N / mm 2 Between, especially at 10 N / mm 2 and 15 N / mm 2 Between. Especially in the case of uniform fiber nonwoven materials, constant and uniform surface pressure ensures that the preform has a constant and uniform material density. To improve stability, the preform is also pressed into final packaging or pressed products, more specifically, at 15 N / mm. 2 Up to 250 N / mm 2 The surface pressure between the two parts is used for pressing. Especially in the case of preforms with constant and uniform material density, constant and uniform surface pressure in this case ensures that the pressed part has a constant and uniform material density.

[0014] Deep drawing of the nonwoven fiber material is performed between a die and a drawing punch, wherein the drawing punch is movable into the die along the drawing direction to deep draw the nonwoven fiber material. Here, the die has a die section on which the preform rests during deep drawing, and said die section extends at least substantially parallel to the drawing direction. The die section has at least partially a curved inner profile in a plane perpendicular to the drawing direction. Preferably, the curved inner profile extends parallel to the drawing direction along the entire longitudinal extension of at least one curved inner profile of the die section. The curved inner profile may extend around the drawing direction with a constant or varying radius, i.e., for example, in an elliptical shape. However, this is not mandatory. The inner profile may also have at least one straight section for forming a straight-walled section of the preform therein.

[0015] The drawing punch has a forming section that is constructed at least substantially corresponding to the die section. The forming section also has an outer contour that is at least partially curved in a plane perpendicular to the drawing direction and corresponding to the die section. However, unlike the inner contour of the die section, the outer contour is constructed to gradually taper against the drawing direction, at least partially, and therefore in at least one curved region of the outer contour. Furthermore, this gradual taper against the drawing direction is preferably continuous, particularly with a constant slope. Additionally, the outer contour tapers against the drawing direction at least in at least one curved region of the outer contour. In other regions of the outer contour, especially in the non-curved regions, the tapering design of the drawing punch can be omitted.

[0016] To achieve deep drawing of the nonwoven fiber material, the nonwoven fiber material is arranged between a bottom die and a drawing punch. The drawing punch is then moved along the drawing direction into the bottom die section of the bottom die. During this movement, the nonwoven fiber material is deeply drawn at least sectionally within the drawing gap between the bottom die section and the drawing section of the drawing punch. The drawing gap is preferably located between the free end of the drawing punch and the bottom die section. This gap allows the nonwoven fiber material to be drawn into the bottom die section. Here, the nonwoven fiber material reaches the gap between the bottom die section and the forming section of the drawing punch, where a preform is formed. This preform has at least one curved wall section between the bottom die section and the forming section. More specifically, this curved wall section is in a plane perpendicular to the drawing direction and corresponds to and is adjacent to the curved inner contour of the bottom die section and the curved outer contour of the forming section of the drawing punch. Corresponding to the gradually tapering shape of the forming section at least in the wall section, at least one curved wall section is formed with a wall thickness that preferably increases continuously in the opposite direction of stretching. Here, the preform preferably fills the gap between the bottom mold section and the forming section, and preferably fills not only in the at least one curved wall section, provided that the preform is not composed of a single circumferential curved wall section.

[0017] During the deep drawing process of the nonwoven fiber material, as the drawing punch moves further into the bottom die, an increasing amount of nonwoven fiber material is drawn into the bottom die section between at least one curved inner contour of the bottom die section and at least one curved outer contour of the forming section. Here, the material is only partially compacted, resulting in a larger volume of nonwoven fiber material being collected in the corresponding curved wall sections of the preform as the distance from the bottom of the preform increases. Therefore, as the distance from the bottom of the preform increases, the wall thickness of the preform in this region increases.

[0018] If, for example, the preform has a circular bottom and curved wall sections uniformly surrounding the stretching direction, loops of nonwoven fiber material with a constant width and (originally) a relatively large diameter are gradually drawn into a bottom die section with a constant diameter. Initially, the circumference of the loops drawn into the bottom die section roughly corresponds to the circumference of the bottom. However, as the loops are rapidly drawn into the bottom die section, these loops, which originally had increasingly larger diameters and therefore increasingly larger circumferences, become increasingly compacted as the stretching punch moves into the bottom die section, so that the diameter or circumference of these loops corresponds to the diameter or circumference of the inner contour of the bottom die section when drawn into the bottom die section. Accordingly, as the distance from the bottom region of the preform increases, the loops of nonwoven fiber material become increasingly compacted, with more and more fiber material being folded into a constant diameter. Therefore, as the stretching depth increases, more and more nonwoven fiber material is simultaneously drawn into the stretching gap, and the corresponding rings made of nonwoven fiber material form increasingly thick walls after being drawn into the bottom die section.

[0019] This principle applies to the curved wall sections of the preform and is related to their radii of curvature. Conversely, it does not apply to the possible straight wall sections. During the movement of the drawing punch into the die section, the same amount of nonwoven fiber material is always drawn into the die section, thus the wall thickness of the preform in the straight wall sections can remain constant along the drawing direction of the drawing punch. Taking these principles into account, preforms with circular, elliptical, or approximately rectangular cross-sections can be formed without problems, for example.

[0020] The previously discussed material buildup in at least one curved wall section of the preform can be utilized during pressing of the preform to shape it into a conical package without tearing it during pressing. The preform extends at least partially during pressing. However, this does not cause the preform to tear because the increased wall thickness in at least one curved wall section (previously provided by the material buildup) provides the material needed for the extension. This is particularly applicable because the preform is widened more intensely during pressing as the distance from the bottom of the preform increases, and more and more material is provided for the corresponding extension of the preform as the distance from the bottom of the preform increases. In the preform, the nonwoven material is first built up in at least one curved wall section so that this wall section can extend again during pressing and thus unfold. Thus, the material buildup is at least partially reversed. Because the nonwoven material of the preform is only pressed to a limited extent, the nonwoven material of the preform can still be adequately shaped, especially extended, during pressing. Therefore, the surface pressure of the preform during the deep drawing process should be limited.

[0021] To provide the advantages described above, the forming apparatus is preferably configured to perform the method described above. Specifically, the forming apparatus has a bottom die with a bottom die section having an inner contour that extends at least substantially parallel to the stretching direction and is at least partially curved in a plane perpendicular to the stretching direction. Because the inner contour of the bottom die section extends parallel to the stretching direction, the outer contour of the formed preform remains constant along the stretching direction. Only the inner contour of the preform changes against the stretching direction. For this purpose, the stretching punch has a forming section having an outer contour that is at least partially curved in a plane perpendicular to the stretching direction and corresponding to the bottom die section, which preferably tapers continuously against the stretching direction.

[0022] As the forming section of the drawing punch gradually tapers, more and more material can be accommodated in the gap between the die section and the forming section in the drawing area of ​​the nonwoven fiber material as the drawing punch gradually moves into the bottom die section. Therefore, in at least one curved wall section of the preform, more material accumulates as the distance from the bottom of the preform increases. In the gap between the die section and the forming section, as the distance from the bottom of the preform increases, i.e., as the drawing depth increases, not only does the wall thickness of the preform that can be accommodated increase, but also the amount of nonwoven fiber material that can be accommodated. Furthermore, the gradual taper of the outer contour of the drawing punch matches the previously described material accumulation in the curved wall section of the preform, such that during deep drawing, the nonwoven fiber material in at least one curved wall section of the preform is pre-pressed by a surface pressure that is at least substantially constant at the height of the curved wall section, thus preferably having a constant material density at the height of the curved wall section. Here, the surface pressure is preferably 6 N / mm². 2 Up to 22 N / mm 2 Between, especially at 10N / mm 2 Up to 15 N / mm 2 between.

[0023] In the region of the possible straight-walled section of the preform, a gradually tapering molding section is not necessary because there is no material buildup there. The gap width between the bottom mold section and the molding section can still be chosen such that the nonwoven fiber material of the preform has at least substantially constant surface pressure along the stretching direction, thereby allowing the preform to have at least substantially constant material density. This surface pressure is preferably also 6 N / mm². 2 Up to 22 N / mm 2 Between, especially at 10 N / mm 2 Up to 15 N / mm 2 between.

[0024] Therefore, regarding the preform, according to the present invention, the preform has an opening, sidewalls, and a bottom region, wherein the sidewall has at least one curved wall section surrounding the central longitudinal axis of the preform. Here, the preform is preferably manufactured by the method according to any one of claims 1 to 6 and / or by means of a molding apparatus according to any one of claims 9 to 11. In at least one curved wall section of the preform, the nonwoven fiber material is folded in the circumferential direction surrounding the central longitudinal axis of the preform.

[0025] Due to the material buildup in at least one curved wall section of the preform as described above, the curved wall section of the preform folds increasingly more strongly from the bottom region of the preform towards the opening, thereby increasing the wall thickness of at least one curved wall section from the bottom region of the preform towards the opening. Here, the increase in wall thickness preferably corresponds to, or at least continuously corresponds to, the folding of the nonwoven fiber material, particularly with a constant slope. Through the folding of the preform in at least one curved wall region, the nonwoven fiber material of the preform can be at least partially unfolded again in at least one curved wall region of the preform, so that the widening of the preform and the extension of the curved wall region can be achieved during subsequent pressing of the preform without simultaneously tearing the preform in the curved wall region.

[0026] In a first particularly preferred embodiment of this method, during the movement of the drawing punch into the die section, the preform is formed with an outer contour oriented at least substantially parallel to the drawing direction. This is achieved by the die section having an inner contour oriented at least substantially parallel to the drawing direction, thereby simplifying and making the process of deep drawing the nonwoven material into the preform more reliable and reproducible. This is applicable in at least one curved wall section anyway. However, more preferably, for the same reason, this is also provided in possible straight wall sections of the preform. Here, it is also particularly preferred that the outer contour of the preform is oriented parallel to the drawing direction because the inner contour of the die section is also oriented parallel to the drawing direction.

[0027] Alternatively or additionally, during the movement of the drawing punch into the die section, the preform may be formed with an inner contour in at least one curved wall section, which is inclined at least 0.3°, preferably at least 1°, particularly at least 2°, and further 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 allows for the consideration that, due to material buildup, particularly due to wrinkles formed in the curved wall section, the wall thickness increases with increasing drawing depth. Furthermore, during deep drawing, the inner contour of the preform enables the surface pressure of the fibrous nonwoven material of the preform to remain at least substantially constant along the drawing direction, independent of the drawing depth. Therefore, a material density at least substantially constant along the drawing direction can be provided to the preform.

[0028] In addition to at least one curved wall section, the preform may also have at least one straight wall section with a wall thickness that is at least substantially constant along the stretching direction. Since there is no bending in the straight wall section, at least substantially the same amount of nonwoven fiber material is drawn between the die section and the forming section of the stretching punch, regardless of the stretching depth of the preform. Therefore, varying wall thickness is not required, and preferably not desired, to provide at least substantially constant surface pressure and / or at least substantially constant material density for the nonwoven fiber material in the straight wall section, which is further preferably at least substantially corresponding to the at least substantially constant surface pressure or material density of the nonwoven fiber material in the curved wall section of the preform.

[0029] At least one straight-wall section of the preform can be suitably formed using an inner contour of the preform extending at least substantially parallel to the stretching direction and an outer contour of the preform extending at least substantially parallel to the stretching direction. For this purpose, the corresponding inner contour of the die section and the corresponding outer contour of the forming section of the stretching punch can be oriented parallel to the stretching direction. This leads not only to process simplification but also to equipment simplification.

[0030] During the movement of the stretching punch into the die section, the fibrous nonwoven material of the preform between the die section and the forming section can be compacted to a material density that is at least substantially constant under a surface pressure. Then, suitable and uniform subsequent forming can be performed during the pressing of the preform into a package, while widening the preform. This is particularly applicable when the surface pressure is constant around and along the stretching direction.

[0031] During deep drawing between the drawing punch and the die, it is preferable to heat at least the forming section and / or the die section to a temperature between 40°C and 160°C, particularly between 50°C and 140°C. This allows the fibers of the nonwoven material to slide better relative to each other during the forming process, making the nonwoven material less prone to tearing. For the same reason, the die and / or the pressing punch of the press can also be heated.

[0032] In contrast, the nonwoven fiber material can be folded when drawn into at least one curved wall section of the preform. In this way, a wall thickness that preferably increases continuously, especially with a constant slope, is simply and reliably provided in at least one curved wall section. Here, the nonwoven fiber material can be folded more strongly with increasing stretching depth of the preform, and here provides a particularly continuously increasing wall thickness for the preform in the curved wall section with increasing distance from the bottom of the preform.

[0033] Conversely, in at least one possible straight-wall section of the preform, the nonwoven fiber material can preferably be drawn into the die without wrinkles and / or with a material thickness that is at least substantially constant along the stretching direction. This simplifies the deep drawing of the nonwoven fiber material. Furthermore, in the straight-wall section, limited stretching is required only during the subsequent pressing process, which can be provided without problems by the stretching of at least one curved-wall section. This can be achieved particularly easily when the nonwoven fiber material folded in at least one curved-wall section during the deep drawing of the preform is at least partially unfolded again during the subsequent pressing of the preform.

[0034] To facilitate the demolding of the deep-drawn preform, it is suitable to remove the preform from the die along with the preform after it has been formed by the drawing punch. The preform can then be removed from the drawing punch by widening it at least in one bent section. Because the nonwoven fiber material of the preform is minimally pre-pressed, it possesses sufficient elasticity to prevent tearing during removal from the drawing punch.

[0035] The method for manufacturing preforms can be part of a method for manufacturing stackable packaging from preforms formed from nonwoven fiber materials. After the preform is formed according to any one of claims 1 to 6, it can then be placed into the die of a press. Here, the die of the press has a tapered inner profile to form stackable pressed articles. For this purpose, with the wall thickness of the preform decreasing, the preform is pressed in the die of the press by a tapered pressing punch in at least one curved wall section. The sufficiently rigid pressed articles can then be stacked sequentially as packages, or further processed.

[0036] Preferably, when at least one curved wall section of the preform is formed into at least one curved wall section of the pressed part, the wrinkles in the preform in the at least one curved wall section are at least partially unfolded. In this way, the pressed part can be at least partially extended and thus widened relative to the preform without the preform being torn during the subsequent pressing process.

[0037] Furthermore, it is preferable that, when at least one straight-wall section of the preform is formed into at least one straight-wall section of the pressed part, the folds in the preform in at least one curved-wall section are at least partially unfolded. Therefore, the unfolding of the folds in at least one curved-wall section of the preform allows the preform to extend and widen without problems in the region of the straight-wall section of the preform during the pressing process, where there is little or no excess nonwoven material for correspondingly extending and / or widening the preform.

[0038] In a first particularly preferred design of the forming apparatus, the drawing punch is configured such that, within the forming section, in at least one outer contour bent relative to the drawing direction, it gradually tapers at least 0.3°, preferably at least 1°, particularly at least 2°, and further particularly at least 3° relative to the drawing direction. In this way, it works in conjunction with a bottom die section having an inner contour parallel to the drawing direction to achieve a drawing gap geometry that can accommodate more and more nonwoven fiber material as the drawing depth increases. Preferably, the drawing gap geometry is designed such that, during deep drawing of the preform, the nonwoven fiber material is pre-compacted within the drawing gap with at least substantially constant surface pressure, particularly pre-compacted to at least substantially constant material density.

[0039] As needed, the drawing punch can be oriented at least substantially parallel to the drawing direction and / or parallel to the die section in at least one outer contour straight relative to the drawing direction within the forming section. In other words, in the non-bending regions of the forming section, a gradual taper can be omitted. Thus, in addition to the curved wall sections of the preform, straight wall sections of the preform, having at least substantially constant wall thickness along the drawing direction, can be easily and reliably formed. Furthermore, the nonwoven fibrous material in both the curved and straight wall sections can thus withstand at least substantially constant surface pressure. Therefore, at least substantially constant material density can be provided in different wall sections as needed.

[0040] To gently and reliably draw the nonwoven material into the stretching gap, or between the die section and the forming section of the stretching punch, the die may have a circumferential radius at its end opposite to the stretching direction, in the transition to the edge section of the die, which extends at least substantially perpendicular to the stretching direction. For a compact die, a radius between 1 mm and 3 mm is preferred. This radius is the outer radius, allowing the die to be partially rounded outwards towards the edge section within that radius. Thus, the nonwoven material can slide into the stretching gap from the edge section and / or the die section through this rounding.

[0041] Alternatively or additionally, a pressure plate may be provided in the edge section of the bottom die, which slightly presses the sheet-like nonwoven material against the edge section of the bottom die before it is drawn into the stretching gap. This ensures that the nonwoven material is drawn uniformly and reproducibly into the stretching gap between the bottom die section and the forming section of the stretching punch. This, in particular, creates uniform pleats in the preform, especially in at least one curved wall section.

[0042] Alternatively or additionally, a reverse retainer may be provided at the free end adjacent to the drawing punch, close to the nonwoven material on the other side of the drawing punch, and during deep drawing of the preform, slightly presses the nonwoven material in the bottom region of the preform, i.e., at the free end of the drawing punch, against the free end of the drawing punch. For this purpose, the reverse retainer moves together with the drawing punch (and especially similarly) into the bottom die section.

[0043] In a first particularly preferred design of the preform, the outer contour of at least one curved wall section is oriented at least substantially parallel to the central longitudinal axis of the preform. Such a preform can be manufactured particularly simply and reliably. For this purpose, the inner contour of the die section, which is also at least substantially parallel to the central longitudinal axis of the preform and / or oriented in the stretching direction during deep drawing, can be utilized during the deep drawing process of the preform.

[0044] Alternatively or additionally, it is suitable that the inner profile of at least one curved wall section tapers substantially between the bottom region and the opening. In this way, during deep drawing, fibrous nonwoven material can be stacked or folded in at least one curved wall section, which can then be used for widening and stretching the preform when it is pressed into a pressed part or subsequently into a stackable package. Therefore, the tapering inner profile of the preform in at least one curved wall section is also advantageous because, as a result, the fibrous nonwoven material in the preform in at least one curved wall section, particularly in the opening region of the preform, does not need to be pressed too forcefully during preforming, and therefore does not need to be compacted too forcefully. Consequently, the preform can be reliably formed in the subsequent pressing process without tearing.

[0045] To enable simple and reproducible manufacturing of the preform, it is suitable that the sidewall transitions at the end opposite the bottom region to an edge region extending at least substantially perpendicular to the central longitudinal axis of the preform. In this edge region, during the deep drawing of the preform, the nonwoven material can be slightly pressed against the bottom die by a pressure plate. The nonwoven material can then be drawn into the stretch gap in a defined manner, and here it is particularly defined to be folded. Alternatively or additionally, the edge region can also be used to form the edge of the subsequent packaging.

[0046] To provide a relatively constant surface pressure and / or material density for the nonwoven material of the preform in different sections, it is suitable that the bottom region and the ends of at least one curved wall section adjacent to the bottom region have at least substantially the same wall thickness. In these two sections, the nonwoven material is not folded or is not significantly folded, and therefore does not accumulate or accumulates significantly. The opposite is true in the edge regions adjacent to the curved wall regions and in the ends of at least one curved wall section adjacent to the edge regions. However, wrinkle formation and material accumulation in these sections are considerable, so it is suitable that the preform also has at least substantially the same wall thickness in these sections.

[0047] To enable the provision of packages with a variety of different shapes, the sidewalls may have at least one straight wall section extending parallel to the central longitudinal axis of the preform. Corresponding wall sections may be used to form at least approximately straight sidewalls for the package. To ensure that the surface pressure and / or material density of the preform are as uniform as possible in different sections of the preform, it is suitable that at least one straight wall section has at least substantially a constant wall thickness between the bottom region of the preform and the opening. In the case of the straight wall section of the preform, unlike in at least one curved wall section, during deep drawing, approximately the same amount of nonwoven fiber material is always drawn into the drawing gap as the drawing depth increases, wherein the amount of nonwoven fiber material corresponds to the amount of nonwoven fiber material used to form the bottom of the preform. Not only in the bottom region but also in the region of at least one straight wall section, the nonwoven fiber material is preferably arranged in a single layer and without folding. Conversely, in at least one curved wall section, the nonwoven fiber material is preferably arranged with folds, more specifically, with increasing distance from the bottom of the preform, the more folded it becomes.

[0048] Therefore, alternatively or additionally, it is also preferred that the wall thickness of at least one straight-wall section is at least the same as the wall thickness of the bottom region, and / or the same as the wall thickness of the end of at least one curved-wall section adjacent to the bottom region. In all these regions, the nonwoven fiber material is preferably disposed at least substantially in a single layer, so as to achieve the desired uniform surface pressure while making the wall thickness and, in particular, the material density of the preform the same or at least very similar.

[0049] Since material buildup and wrinkles related to the stretching depth of the nonwoven material need not be considered in at least one straight-wall section, it is appropriate for the inner and outer contours of at least one straight-wall section to extend at least substantially parallel to the central longitudinal axis of the preform for easier deep drawing of the preform.

[0050] For the reasons described above, the preform according to the invention can have a draw ratio greater than 0.3, preferably greater than 0.5, particularly greater than 0.75, and even more particularly greater than 1.0. The draw ratio here corresponds to the ratio of the height of the preform to its minimum outer width. Therefore, in the case of a preform with a circular bottom region, the draw ratio corresponds to the ratio of the height of the preform to its outer diameter. Attached Figure Description

[0051] The invention is explained in detail below with reference to the accompanying drawings, which show only one embodiment. The drawings show: Figure 1 A schematic side view shows the molding apparatus according to the invention. Figures 2A-2B Perspective views show a preform with a circular bottom and a preform with an approximately rectangular bottom according to the present invention. Figures 3A-3C The steps of a method for manufacturing a preform according to the present invention are illustrated in a schematic cross-sectional view. Figures 4A-4B A cross-sectional view shows preforms in different states according to the invention, and Figure 5 Shown in top view Figure 2B Details of the preform in the process, Figures 6A-6B A schematic cross-sectional view illustrates the method according to the invention, achieved by deep drawing... Figure 5 The forming of the preform in the straight-walled and curved-walled sections, the straight-walled and curved-walled sections corresponding to... Figure 5 The cross-sections VIA-VIA and VIB-VIB, Figures 7A-7B A perspective view is shown of the invention according to the method described above. Figures 2A-2B Pressed parts manufactured from preformed parts. Detailed Implementation

[0052] exist Figure 1The diagram schematically illustrates a forming apparatus 1 for deep drawing a preform 2 from a nonwoven fiber material 3 and for pressing the preform 2 into a pressed part 4 or a package. The nonwoven fiber material 3 is provided as a roll, drawn from a winding 5, and cut in a cutting station 6. For this purpose, the cutting station 6 has a support 7 and a cutting section 8, with the nonwoven fiber material 3 disposed between them. The cut pieces 9 generated in the cutting station 6 are independently but simultaneously deep drawn into preforms 2 in a deep drawing station 10. For this purpose, the deep drawing station 10 includes a bottom die 11 and a drawing punch 12 for each cut piece 9, using the drawing punch 12 to draw each cut piece 9 of the nonwoven fiber material 3 into the bottom die 11. After the stretching punch 12 is removed from the bottom die 11 along with the preforms 2, the preforms 2 are removed from the stretching punch 12 and placed into the die 14 of the press 15 in the pressing station 13. There, the preforms 2 are pressed into conical and therefore stackable pressed parts 4 or packages by the pressing punch 16 in the die 14 of the press 15. Subsequently, the pressed parts 4 are conveyed to the blanking station 17, where the edges of the pressed parts 4 are appropriately blanked by removing excess nonwoven material 3. After the edges of the pressed parts 4 are shaped in the blanking station 17, the pressed parts 4 or packages are stacked sequentially into one or more stacks 19 in the stacking station 18.

[0053] Because the preforming step of the cut articles 9 made of the nonwoven fiber material 3 takes longer than the remaining steps of the method described above, the operating cycle of the cutting station 6, pressing station 13, punching station 17, and stacking station 18 is half the operating cycle of the deep drawing station 10. Therefore, in the illustrated, and in this regard preferred, method, four blanks 20 are processed in one cycle in the cutting station 6, pressing station 13, punching station 17, and stacking station 18, while eight blanks 20 are processed in one cycle in the deep drawing station 10. This is illustrated by the blanks 20 in the form of the individual cut articles 9, which are processed in… Figure 1 The information is shown below each of the stations 6, 10, 13, 17, and 18.

[0054] exist Figure 2AThe preform 2 is shown in a perspective view. The preform 2 has a circular bottom region 21, sidewalls 22 with at least a substantially constant radius around the central longitudinal axis L of the preform 2, and an edge region 24 surrounding the opening 23 of the preform 2. The sidewalls 22 can be understood as sidewalls composed of a single, completely encircling curved wall segment 25. The preform 2 is deep-drawn from a planar cut 9 of nonwoven fiber material 3. Starting from the region of the nonwoven fiber material 3 that constitutes the bottom region 21 of the preform 2, multiple rings of constant width can be defined around the bottom region 21. The further these rings are from the bottom region 21, the larger their circumference and the more nonwoven fiber material 3 they include. During the deep-drawing process, the further the bottom region 21 is from the planar region of the nonwoven fiber material 3, the larger the equal-width rings drawn into the stretch gap, i.e., the larger the circumference of the rings and the more fiber material 3 they include, but the outer diameter of the stretch gap remains unchanged. Therefore, the individual loops of the planar nonwoven material 3 must be gathered until they correspond to the circumference of the stretch gap. Thus, the loops with larger initial circumferences drawn into the stretch gap later must be gathered and folded more forcefully to fit into the stretch gap compared to the smaller loops drawn in earlier. In the case of the preform 2, this results in the wall thickness of the sidewall 22 increasing from the bottom region 21 of the preform 2 towards the edge region 24 and / or the opening 23, and more specifically, in the illustrated preform 2, the wall thickness increases continuously and at a constant slope α. The wrinkles of the nonwoven material 3 during the deep drawing process of the preform 2 are illustrated by lines in the edge region extending toward the opening 23 of the preform. Furthermore, the wrinkles 27 of the nonwoven material 3 in the sidewall 22 are illustrated by lines extending from the opening 23 toward the bottom region 21.

[0055] exist Figure 2B The diagram shows a preform 28 comprising a generally rectangular bottom region 29 with rounded corners 30, sidewalls 31 having curved wall sections 32 and straight wall sections 33 (alternating circumferentially), and an edge region 34 surrounding an opening 35 of the preform 28. On the curved wall sections 32, corresponding to the principles described above, the further the bottom region 29 is from the planar nonwoven fiber material 3, and therefore the further it is drawn, the more nonwoven fiber material 3 is drawn in. On each curved wall section 32, the further away the loop sections drawn into the stretch gap and extending approximately 90° are from the bottom region 29, the longer these loop sections are and therefore include more nonwoven fiber material 3. The longer the corresponding loop sections are, the more forcefully they must be gathered and folded in order to be drawn into the stretch gap.

[0056] The situation is different in the straight-wall section 33. During deep drawing, a uniformly wide and single-layer strip of nonwoven fiber 3 is always drawn into the stretch gap in the straight-wall section. As a result, the wall thickness in the straight-wall section 33 between the bottom region 29 and the edge region 34 is at least substantially constant, while the wall thickness in the curved-wall section 32 increases continuously from the bottom region 29 to the edge region 34 with a constant slope α. As illustrated by the lines extending toward the curved-wall section 32 in the edge region 34, and by the lines extending toward the bottom region 29 in the curved-wall section 32, the nonwoven fiber 3 is folded only in the curved-wall section 32 and the section of the edge region 34 connected to the curved-wall section 32. In the straight-wall section 33, the nonwoven fiber 3 is folded less, as in the section of the edge region 34 connected to it.

[0057] exist Figures 3A-3C The image, in cross-sectional view, shows the deep drawing of the preform 28 in the region of at least one curved wall section 32 at the deep drawing station 10. This is as shown in... Figure 3A As shown, firstly, a planar cut 9 of the nonwoven material 3 is placed on the bottom mold 11. Next, the stretching punch 12 moves towards the nonwoven material 3 with its free end, and on the other side of the nonwoven material 3, the reverse retainer 36 moves towards the nonwoven material 3, such that the nonwoven material 3 in the bottom region 29 of the preform 28 is slightly compressed between the stretching punch 12 and the reverse retainer 36. Furthermore, a pressure plate 37 moves from the stretching punch 12 side towards the planar nonwoven material 3. The pressure plate 37 slightly presses the nonwoven material 3 against the edge section 38 of the bottom mold 11, which is oriented at least substantially perpendicular to the stretching direction Z and parallel to the planar nonwoven material 3.

[0058] Then, according to Figure 3B The drawing punch 12 moves into the bottom die section 39 of the bottom die 11 along the drawing direction Z indicated by the arrow. During this process, the reverse retainer 36 also moves into the bottom die section 39. Here, a drawing gap 41 is constructed between the bottom die section 39 and the drawing section 40 of the drawing punch 12 at its free end. The nonwoven fiber material 3 is gradually drawn into the drawing gap 42 between the forming section 43 of the drawing punch 12 and the bottom die section 39 through this drawing gap 41. In the drawing punch 12 shown, and in this respect preferred, the forming section 43 is arranged directly adjacent to the drawing section 40 of the drawing punch 12. In order to protect the nonwoven fiber material 3 when it is drawn into the bottom die section 39, and especially to prevent it from breaking, a rounded transition region 44 is provided between the bottom die section 39 and the edge section 38 of the bottom die 11. The bottom die 11 has a radius that is at least substantially equal around this transition region 44.

[0059] The drawing punch 12 has an outer contour in the forming section 43 that tapers at least partially against the drawing direction Z. Here, in the section shown, the outer contour of the forming section 43 has a constant angle α relative to the drawing direction, while the inner contour of the die section 39 is oriented parallel to the drawing direction. Here, the die section 39 and the forming section 43 are curved in the circumferential direction to form a curved wall section 32 of the preform 28 between them.

[0060] Because the drawing punch 12 gradually tapers at least locally in the forming section 43, therefore, as in Figure 3C As shown, the stretching gap 42 between the forming section 43 and the bottom die section 39 of the stretching punch 12 gradually widens at the upper edge of the bottom die section 39, that is, it gradually widens as the stretching depth T of the preform 28 increases. More and more nonwoven fiber material 3 can be accommodated in the increasingly wider stretching gap 42. Here, with the same surface pressure of the nonwoven fiber material 3 in the stretching gap 42, the more nonwoven fiber material 3 is accommodated as the stretching depth T increases, and the degree of increase corresponds to the fact that, as the stretching depth T increases, more nonwoven fiber material 3 is drawn into the stretching gap 42 in a folded form in the curved wall section 32 of the preform 28.

[0061] To demold the preform 28, the drawing punch 12 can be removed from the bottom die 11 together with the preform 28. The preform 28 is only slightly pre-compacted during the deep drawing process, so that the preform 28 can be easily and without damage removed from the drawing punch 12 before using the drawing punch 12 to deep draw another preform 28.

[0062] exist Figure 4A China and Israel Figures 3A-3C The same view shows the preform 28, still positioned on the drawing punch 12, but the drawing punch 12 is not shown in this view for clarity. Figure 4A In the illustrated configuration, the preform 28 has an outer contour that, like the inner contour of the bottom die section 39, extends parallel to the stretching direction Z of the stretching punch 12 in the corresponding region. Here, the bottom region 29 of the preform 28 is oriented at least substantially perpendicular to the outer contour in at least one curved wall section 32. The inner contour of the preform 28 is constructed to gradually taper upwards toward the opening 35 of the preform 28 in the at least one curved wall section 32 shown. Here, the inner contour slopes continuously inwards against the stretching direction Z or the central longitudinal axis L in the same manner as the forming section 43 of the stretching punch 12, with a constant slope α. Here, the slope angle α can be, for example, at least 0.3°, preferably at least 1°. The preform 28 has rounded edges at the transition from the bottom region 29 to the sidewall 31, and at the transition from the sidewall 31 to the edge region 34, but these are not shown for clarity.

[0063] When the preform 28 is removed from the drawing punch 12, the preform 28 is widened in the region of at least one bent wall section 32. Therefore, the preform 28 removed from the drawing punch 12 can have [a certain shape / feature] in at least one bent wall section 32. Figure 4B The shape shown indicates that the inner contour of the preform 28 in at least one curved wall section 32 is at least substantially parallel to the stretching direction Z or the central longitudinal axis L, and at least substantially perpendicular to the orientation of the bottom region 29. Here, the outer contour of the at least one curved wall section 32 widens against the stretching direction Z or the central longitudinal axis L. The preform 28 has rounded edges at the transition from the bottom region 29 to the side wall 31, and at the transition from the side wall 31 to the edge region 34, but these are not shown for clarity.

[0064] exist Figure 5 A top view shows Figure 2B Details of the preform 28 are shown, including curved wall sections 32 and straight wall sections 33. Based on the viewing direction, only the edge region 34 belonging to the preform 28 and the bottom region 29 with straight edges 45 and rounded corners 30 are shown. Figures 6A-6B The diagram shows the deep drawing of the straight-wall section 33 and the curved-wall section 32 of the preform 28, wherein the preform 28 is drawn in accordance with... Figure 5 The cross-sectional views of the cutting planes VIA-VIA and VIB-VIB are shown.

[0065] according to Figure 6A The drawing punch 12 has moved into the die section 39 along the drawing direction Z with its forming section 43. Here, the nonwoven material 3 is slightly held between the edge section 38 of the die 11 and the pressure plate 37, so that the nonwoven material 3 can be further drawn 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 moves further into the die section 39. During the continued movement of the drawing punch 12 into the die section 39 along the drawing direction Z, the nonwoven material 3 is slightly pressed against the free end of the drawing punch 12 by the reverse retainer 36 at the opposite end of the drawing punch 12. In the region shown, the die section 39 has an inner contour that extends parallel to the drawing direction Z. The top side of the edge section 38 of the die 11 extends at least substantially perpendicular to the drawing direction. In the illustrated, and in this regard preferred embodiment, this is also true for the free end of the drawing punch 12 and the top side of the reverse retainer 36. The outer contour of the forming section 43 of the drawing punch 12 extends parallel to the drawing direction Z, and therefore extends parallel to the inner contour of the bottom die section 39.

[0066] Therefore, in the straight-wall section 33 of the preform 28 shown, the stretching gap 42 between the bottom die section 39 and the forming section 43 of the stretching punch 12 is constant along the stretching direction Z. The nonwoven fiber material 3 is disposed in a single layer within the stretching gap 42, wherein the stretching gap 42 is chosen to be wide enough that the nonwoven fiber material 3 is pre-compacted to a lesser extent and withstands a load of 6 N / mm². 2 With 22 N / mm 2 Uniform surface pressure between them. Given a suitable original nonwoven fiber material, this preferably results in 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 degree in the bottom region 29. Conversely, in the edge region 34 of the preform 28, the nonwoven fiber material 3 is less compacted so that it can continue to flow into the stretch gap 42 without significant resistance. The preform 28 has a wall thickness or thickness d1 in the edge region 34 that is greater than the wall thickness d2 in the stretch 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 or thickness d2 = d3.

[0067] exist Figure 6B The cross-sectional view shows the deep drawing of the curved wall section 32. This is largely as described above in conjunction with the deep drawing of the straight wall section 33. However, according to... Figure 6A The difference between the deep drawing of the straight-wall section 33 and the deep drawing is that, according to Figure 6B During the deep drawing of the curved section 32, the outer contour of the forming section 43 of the drawing punch 12 is not parallel to the drawing direction Z, nor is it parallel to the inner contour orientation of the bottom die section 39. Instead, the forming section 43 of the drawing punch 12 gradually tapers against the drawing direction Z. The forming section 43 is inclined at a constant angle α relative to the drawing direction Z, such that the drawing gap 42 between the forming section 43 and the bottom die section 39 (which has an inner contour parallel to the drawing direction Z) widens against the drawing direction Z with a corresponding constant slope α.

[0068] The stretch gap 42 is completely filled with the nonwoven fiber 3 along its entire height. The nonwoven fiber 3 is folded before being drawn into the stretch gap 42, and more specifically, the deeper the stretching punch 12 moves into the bottom die 11, the more the nonwoven fiber 3 is folded. Thus, as the stretching punch 12 continues to move in and as the stretching depth T increases, more and more nonwoven fiber 3 is drawn into the stretch gap 42, wherein the widening stretch gap 42 provides more and more space for the drawn-in nonwoven fiber 3. Here, in the illustrated, and in this regard preferred embodiment, the increase in the width of the stretch gap 42 corresponds in this way to the increase in the amount of nonwoven fiber 3 to be drawn in and the increase in its folds, such that the surface pressure of the nonwoven fiber 3 in the curved wall section 32 is at least substantially constant along the stretching direction Z, and furthermore, at least substantially corresponds to the surface pressure of the nonwoven fiber 3 in the straight wall section 33 and in the bottom region 29. Thus, a preform 28 is preferably obtained, wherein the material density in the curved wall section 32 is at least substantially constant in the tensile direction Z, and at least substantially corresponds to the material density in the straight wall section 33 and the bottom region 29.

[0069] The nonwoven fiber material 3 is folded not only in the curved wall section 32 but also in the edge region 34. However, due to the pressure plate 37, the surface pressure of the nonwoven fiber material 3 in the edge region 34 is less than the surface pressure in the stretch gap 42. For this reason, the wall thickness or thickness d1 of the nonwoven fiber 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 fiber material 3 at the upper end of the stretch gap 42 (between the forming section 43 and the bottom die section 39 of the stretch punch 12). However, the wall thicknesses d1 and d2 of the preform 28 at the above two locations are greater than the wall thicknesses d3 and d4 at the lower end of the stretch gap and in the bottom region 29, wherein the wall thicknesses d3 and d4 mentioned later are at least approximately the same as each other.

[0070] After being removed from the stretching punch 12, preforms 2 and 28 are pressed in the pressing station 13, in the die 14 of the press 15, by means of the pressing punch 16. This pressing is preferably performed using the die 14 at a temperature of 100°C to 200°C and / or using the pressing punch 16 at a temperature of 100°C to 200°C. Through this pressing, a desired result can be obtained. Figures 7A-7BThe pressed parts 46 and 47 are shown. These pressed parts 46 and 47 can be used directly as packaging, or they can be further processed, such as by applying a plastic coating. Here, not only is the wall thickness of the preforms 2 and 28 reduced, but the preforms 2 and 28 are also formed into pressed parts 46 and 47. Therefore, the pressed parts 46 and 47 obtain a tapered shape, which allows them to be stacked on top of each other. During the pressing of the preforms 2 and 28, the surface pressure is 20 N / mm². 2 Up to 30 N / mm 2 Between. The local widening of preforms 2, 28 during pressing results in the extension of at least one curved wall region 25, 32, and consequently causes the nonwoven fiber material 3 in that region to at least partially unfold.

[0071] exist Figure 7A The image shows a pressed member 46, which has a circular bottom region 48, a circular edge region 49, and a surrounding curved wall section 50 connecting the edge region 49 and the bottom region 48. This pressed member 46 is preferably made according to... Figure 2A The preform 2 is made from the preform. The diameter of the curved wall section 32 increases between the bottom region 48 and the edge region 49, allowing similar pressed parts 46 to be easily stacked on top of each other. Figure 7B The image shows a pressed member 47, which has an approximately rectangular bottom region 51 with rounded corners 52. The pressed member 47 is preferably made according to... Figure 2B The preform 28 is formed. Here, straight wall sections 53 and curved wall sections 54 alternate, transitioning into edge regions 55 at their ends away from the bottom region 51. The straight wall sections 53 and curved wall sections 54 slope outward from the bottom region 51 to the edge region 55 to obtain a tapered shape for the pressed part 47, and thus a stackable shape. By tilting the straight wall sections and curved wall sections 53, 54, the fibrous nonwoven material 3 in the curved wall section 32 of the preform 28 is partially unfolded to provide fibrous nonwoven material 3 for the molding of the preform 28 in the pressing station 13.

[0072] Explanation of reference numerals in the attached figures

[0073] 1 Molding device

[0074] 2 Preforms

[0075] 3. Fiber nonwoven materials

[0076] 4 pressed parts

[0077] 5 winding

[0078] 6 Cutting Stations

[0079] 7 Support section

[0080] 8 cutting sections

[0081] 9 Cuttings

[0082] 10 Deep La Station

[0083] 11 Bottom Mold

[0084] 12 drawing punch

[0085] 13 compression stations

[0086] 14 molds

[0087] 15 press

[0088] 16-pressure punch

[0089] 17 Trimming Station

[0090] 18 stacking stations

[0091] 19 piles

[0092] 20 billets

[0093] 21 bottom area

[0094] 22 sidewalls

[0095] 23 openings

[0096] 24 edge areas

[0097] 25-bend section

[0098] 27 pleats

[0099] 28 preforms

[0100] 29 bottom area

[0101] 30 angles

[0102] 31 sidewalls

[0103] 32-bend section

[0104] 33 straight wall section

[0105] 34 Edge Area

[0106] 35 opening

[0107] 36 Reverse retainer

[0108] 37 pressure plate

[0109] 38 edge sections

[0110] 39 Bottom mold section

[0111] 40 stretching section

[0112] 41, 42 Tension gap

[0113] 43 forming section

[0114] 44 Transition Zone

[0115] 45 edge

[0116] 46, 47 Pressed parts

[0117] 48 bottom area

[0118] 49 Edge Area

[0119] 50-degree bend section

[0120] 51 bottom area

[0121] 52 angles

[0122] 53 straight wall section

[0123] 54-bend section

[0124] 55 edge area

[0125] α slope / angle

[0126] d wall thickness / thickness

[0127] L center longitudinal axis

[0128] T stretching depth

[0129] Z-tension direction

Claims

1. A method for manufacturing preforms (2, 28) for further processing into packaging from a planar fibrous nonwoven material (3) by deep drawing using a die (11) and a drawing punch (12) capable of moving into the die (11) in the stretching direction, wherein, The bottom die (11) has a bottom die section (39) having an inner contour that extends at least substantially parallel to the stretching direction (Z) and is at least partially curved in a plane perpendicular to the stretching direction (Z), and wherein the stretching punch (12) has a forming section (43) having an outer contour that is at least partially curved in a plane perpendicular to the stretching direction (Z) and corresponding to the bottom die section (39), the outer contour being at least partially against the stretching direction (Z) and preferably gradually tapering continuously. - In this process, a nonwoven fiber material (3) is arranged between the bottom die (11) and the stretching punch (12), and then the stretching punch (12) is moved into the bottom die section (39) along the stretching direction (Z). - During the movement of the drawing punch (12) into the bottom die section (39), the nonwoven fiber material (3) is at least partially deep-drawn in the drawing gap (42) between the bottom die section (39) and the drawing section (40) of the drawing punch (12). - During the movement of the stretching punch (12) into the bottom die section (39), a preform is formed between the bottom die section (39) and the forming section (43), the preform having at least one curved wall section (25, 32) in a plane perpendicular to the stretching direction (Z), and having a wall thickness (d2, d4) that increases in the at least one curved wall section (25, 32) against the stretching direction (Z), preferably continuously.

2. The method according to claim 1, - During the movement of the stretching punch (12) into the bottom die section (39), a preform (2, 28) is formed, the preform having an outer contour oriented at least substantially parallel to the stretching direction (Z) in at least one curved wall section (25, 32), and - in, Preferably, during the movement of the stretching punch (12) into the bottom die section (39), a preform (2, 28) is formed, the preform having an inner contour in at least one curved wall section (25, 32) that is inclined at least 0.3°, preferably at least 1°, particularly at least 2°, and more particularly at least 3° relative to the outer contour of the preform (2, 28), the inner contour of the bottom die section (39), and / or the stretching direction (Z).

3. The method according to claim 1 or 2, - Wherein, the preform (28) has at least one straight-wall section (33) having a wall thickness (d2) that is at least substantially constant along the stretching direction (Z), and - in, Preferably, at least one straight wall section (33) has an inner profile extending at least substantially parallel to the stretching direction (Z) and an outer profile extending at least substantially parallel to the stretching direction (Z).

4. The method according to any one of claims 1 to 3, - During the movement of the stretching punch (12) into the bottom die section (39), the nonwoven material (3) of the preform (2, 28) is compacted, particularly around the stretching direction (Z) and along the stretching direction (Z), by at least substantially constant surface pressure between the bottom die section (39) and the forming section (43), said surface pressure preferably being 6 N / mm. 2 and 22 N / mm 2 Between, especially at 10 N / mm 2 and 15 N / mm 2 Between, and / or - Among them, During the movement of the drawing punch (12) into the bottom die section (39), at least the forming section (43) and / or the bottom die section (39) are heated to a temperature between 40°C and 160°C, particularly between 50°C and 140°C.

5. The method according to any one of claims 1 to 4, - Wherein, when the nonwoven fiber material (3) is drawn into the bottom mold (11), the nonwoven fiber material (3) is folded in at least one curved wall region (25, 32), and - Preferably, the nonwoven fiber material (3) is drawn into the bottom mold (11) in at least one straight wall section (33) without wrinkles and / or with a material thickness that is at least substantially constant along the stretching direction (Z).

6. The method according to any one of claims 1 to 5, - Wherein, the drawing punch (12) is removed from the bottom die (11) after forming the preform (2, 28), and - in, Preferably, the preform (2, 28) is then removed from the stretching punch (12) under the condition that the preform (2, 28) is widened in at least one bent wall section (25, 32).

7. A method for manufacturing stackable packaging from preforms (2, 28) formed from fibrous nonwoven materials (3), - in, The preform (2, 28) is formed according to any one of claims 1 to 6. - Wherein, the preforms (2, 28) are placed into the die (4) of a press with a tapered inner profile, and as the wall thickness (d1-d4) of the preforms (2, 28) decreases, they are pressed in the die (4) by a tapered pressing punch (16) in at least one curved wall section (25, 32), and - Preferably, the successively pressed packages are stacked on top of each other.

8. The method according to claim 7, - Wherein, when 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 pressed part, the folds (27) of the preform (2, 28) in at least one curved wall section (25, 32) are at least partially unfolded, and / or - Among them, When at least one straight wall section (33) of a preform (28) is formed into at least one straight wall section (53) of a pressed part, the wrinkles (27) in at least one curved wall section (32) of the preform (28) are at least partially unfolded.

9. A forming apparatus (1) for manufacturing preforms (2, 28) from planar fibrous nonwoven material (3) preferably by means of the method according to any one of claims 1 to 8 by deep drawing using a bottom die (11) and a drawing punch (12) capable of moving into the bottom die (11) in the stretching direction (Z). Its features are, The bottom die (11) has a bottom die section (39) having an inner contour that extends at least substantially parallel to the stretching direction (Z) and is at least partially curved in a plane perpendicular to the stretching direction (Z), and wherein the stretching punch (12) has a forming section (43) having an outer contour that is at least partially curved in a plane perpendicular to the stretching direction (Z) and corresponding to the bottom die section (39), the outer contour being at least partially against the stretching direction (Z) and preferably gradually tapering continuously.

10. The molding apparatus according to claim 9, Its features are, The drawing punch (12) in the forming section (43) tapers gradually with respect to the drawing direction (Z) at least 0.3°, preferably at least 1°, especially at least 2°, and further especially at least 3° in at least one outer contour bent relative to the drawing direction (Z), and / or The drawing punch (12) is oriented at least substantially parallel to the drawing direction (Z) and / or parallel to the bottom die section (39) in at least one outer contour that is straight relative to the drawing direction (Z) in the forming section (43).

11. The molding apparatus according to claim 9 or 10, Its features are, The bottom mold (11) is above the bottom mold section (39), and has a circumferential radius at its end opposite to the stretching direction (Z) in the transition to the edge section (38) of the bottom mold (11), the edge section (38) extending at least substantially perpendicular to the stretching direction (Z), the radius being particularly between 1 mm and 3 mm.

12. A preform (2, 28) made of a nonwoven fiber material (3), preferably by means of the method according to any one of claims 1 to 6 and / or by means of the molding apparatus (1) according to any one of claims 9 to 11, for further processing into packaging, having an opening (23, 35), sidewalls (22, 31) and a bottom region (21, 29), wherein, The sidewalls (22, 31) have at least one curved wall section (25, 32) surrounding the central longitudinal axis (L) of the preform (2, 28). Its features are, The nonwoven fiber material (3) is folded more and more from the bottom region (21, 29) of the preform (2, 28) toward the opening (23, 35) in at least one curved wall section (25, 32) in the circumferential direction around the central longitudinal axis (L) of the preform (2, 28), and the wall thickness (d2, d4) of at least one curved wall section (25, 32) gradually increases from the bottom region (21, 29) of the preform (2, 28) toward the opening (23, 35), preferably corresponding to the folds of the nonwoven fiber material (3), or at least substantially continuously increasing.

13. The preform according to claim 12, Its features are, The outer contour of at least one curved wall section (25, 32) is oriented at least substantially parallel to the central longitudinal axis (L) of the preform (2, 28), and / or the inner contour of at least one curved wall section (25, 32) tapers at least substantially between the bottom region (21, 29) and the opening (23, 35), and / or The sidewalls (22, 31) transition at their ends opposite the bottom regions (21, 29) into edge regions (24, 34) that extend at least substantially perpendicular to the central longitudinal axis (L) of the preform (2, 28), and / or The bottom regions (29, 48) and the ends of at least one curved wall section (25, 32) adjacent to the bottom regions (21, 29) and / or the edge regions (24, 34) and the ends of at least one curved wall section (25, 32) adjacent to the edge regions (24, 34) have at least substantially the same wall thickness (d1-d4).

14. The preform according to claim 12 or 13, Its features are, The sidewall (31) has at least one straight wall section (33) extending parallel to the central longitudinal axis (L) of the preform (28), and Preferably, at least one straight wall section (33) has at least substantially constant wall thickness (d2) between the bottom region (29) of the preform (28) and the opening (35).

15. The preform according to claim 14, Its features are, The wall thickness (d2) of at least one straight wall section (33) is at least equal to the wall thickness (d3, d4) of the bottom region (29) and / or the wall thickness (d3, d4) of at least one curved wall section (25, 32) adjacent to the bottom region (29), and / or The inner and outer contours of at least one straight-wall section (33) extend at least substantially parallel to the central longitudinal axis (L) of the preform (28).

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