Formation of waveforms within sheet material

Abstract

An apparatus for crimping a material sheet (1), comprising: a corrugated surface (12); a transport mechanism for the material sheet to pass over the corrugated surface; and a pressurized air outlet (20) configured to apply pressurized air (21) toward the material sheet in order to press the material sheet against the corrugated surface and thereby crimp the material sheet, wherein the corrugated surface has a waveform substantially aligned with the direction of movement of the material sheet.

Description

Technical Field

[0001] The present disclosure relates to a method and an apparatus for forming a waveform in a sheet material by pressing the sheet material against a waveform surface with pressurized air.

Background Art

[0002] It is known to use rollers to process sheet materials in a wide range of industries. For example, rollers are used in the rolling process in the tobacco industry. In such a process, an unrolled material sheet 1 (for example, in the form of a tobacco cast leaf band or a sheet of polylactic acid (PLA)) passes between a first rolling roller 3 and a second rolling roller 4 of a rolling device (as shown in FIG. 1) to form a rolled material sheet 2. The rolling rollers 3, 4 each have a first end 3a, 4a and a second end 3b, 4b, between which longitudinal axes A, B extend. The rollers 3, 4 are each driven to rotate in opposite directions, that is, the first roller 3 rotates in a first direction and the second roller 4 rotates in a second opposite direction (as indicated by the arrows in FIG. 1).

[0003] Typically, each of the rolling rollers 3, 4 has a pattern formed on its circumferential working surface. The patterns are configured to cooperate with each other in use. For example, a pattern of circumferential grooves on the circumferential working surface of the first rolling roller 3 may be configured to cooperate with a pattern of ridges on the circumferential working surface of the second rolling roller 4. In use, the first rolling roller 3 and the second rolling roller 4 are arranged such that one pattern cooperates with or meshes with the other pattern, whereby the unrolled material sheet 1 passing between them is rolled to form the rolled material sheet 2.

[0004] Figures 2 and 3 show exemplary patterns of mesh-like circumferential grooves 5 and 6 on the crimp rollers 3 and 4. In Figure 2, the circumferential grooves 5 and 6 generally have a square wave profile, while in Figure 3, the circumferential grooves 5 and 6 generally have a sinusoidal wave profile. In each case, the circumferential grooves 5 and 6 have heights 7 and 8 and widths 9 and 10. Note that the circumferential working surfaces of the crimp rollers 3 and 4 should not actually come into contact with each other. Otherwise, it will not be possible to accommodate the material sheets 1 and 2 between the crimp rollers 3 and 4.

[0005] If the patterns on the circumferential working surfaces of the crimping rollers 3 and 4 are misaligned, the resulting patterns on the material sheets 1 and 2 passing between the rollers 3 and 4 for processing may not be optimally formed or may not be formed at all. On the crimping rollers 3 and 4 used in the tobacco industry, the patterns on their respective circumferential working surfaces (e.g., multiple grooves and ridges) are typically formed by features on the millimeter or micrometer scale. On the other hand, the material sheets 1 and 2 may be relatively thin. Therefore, the relative alignment of the first and second crimping rollers 3 and 4, and thus the relative alignment of the patterns on their circumferential working surfaces, must be very precise in order to adequately process the material sheets 1 and 2 between them.

[0006] Before passing material sheets 1 and 2 through the crimping machine for processing, it may be necessary to move one or both of the crimping rollers 3 and 4. For example, the thickness of material sheets 1 and 2 may differ from the thickness of previously processed material sheets 1 and 2, and therefore different spacings may be required between the circumferential working surfaces of the first crimping roller 3 and the second crimping roller 4. Furthermore, one or both of the crimping rollers 3 and 4 may need to be repaired or replaced, for example, due to wear over time of the patterns on one or both of the crimping rollers 3 and 4 during use. If the pattern features on the circumferential working surfaces are very small in scale (e.g., less than 200 μm), such as in crimping rollers 3 and 4 used in the tobacco industry, the wear of the patterns may cause the rollers 3 and 4 to fail relatively quickly, preventing them from properly processing the material sheets 1 and 2 passing between them. Therefore, it may be necessary to position the first crimping roller 3 and the second crimping roller 4 relatively frequently.

[0007] Positioning or repositioning the first crimping roller 3 and the second crimping roller 4 may involve moving one or both of the rollers 3 and 4, measuring the distance between them to determine their alignment, and then moving one or both of the rollers 3 and 4 again to further modify their relative positioning based on the measured distance. This process of measurement and movement typically has to be repeated multiple times to achieve an acceptable degree of alignment between the first crimping roller 3 and the second crimping roller 4. Typically, the adjustment of the rollers 3 and 4 is done on a micrometer scale, and the adjustment is difficult and time-consuming. Therefore, ensuring an acceptable level of alignment between the first crimping roller 3 and the second crimping roller 4 when positioning or repositioning them relative to each other can be time-consuming and difficult to achieve in practice. During this positioning or repositioning, the crimping device is offline and consequently unable to process the material sheets 1 and 2. Therefore, the operation of the crimping device is relatively expensive due to the downtime required for the positioning or repositioning of the first crimping roller 3 and the second crimping roller 4.

[0008] Inaccurate positioning or alignment of one or both of the first crimp roller 3 and the second crimp roller 4 can cause various problems and impair the quality and consistency of the crimped material sheet 2. For example, if the material sheet 2 is not crimped sufficiently (because the first crimp roller 3 and the second crimp roller 4 are too far apart), the under-crimped material sheet 2 may tend to expand with excessive force when gathered and wrapped in a wrapper to form a rod-shaped article. This can cause the wrapper to tear or peel along the adhesive lines. Conversely, if the material sheet 2 is over-crimped (because the first crimp roller 3 and the second crimp roller 4 are too close together), unwanted cuts may be formed in the material sheet 2. These cuts can lead to larger tears in the material sheet 2 and the formation of loose fragments from the material sheet 2. When crimped material sheets 2 are gathered and rolled with a wrapper to form a rod-shaped article, the presence of cuts or tears can undesirably reduce the draw resistance (RTD) of the finished consumable. Loose material within the rod-shaped article can reduce user satisfaction with the consumable. If the alignment of the first crimping roller 3 and the second crimping roller 4 is improper, the material sheet 2 may be excessively crimped towards one long-axis edge and insufficiently crimped towards the opposite long-axis edge, thus causing both of the problems outlined above.

[0009] It is desirable to provide a method and apparatus for crimping a material sheet that can address issues of roller spacing and alignment. It is also desirable to provide a method and apparatus for crimping a material sheet that can provide simple and reactive adjustment of the crimping process. [Overview of the project]

[0010] According to one aspect of the present invention, an apparatus for crimping a material sheet is provided, comprising a corrugated surface, a transport mechanism for the material sheet to pass over the corrugated surface, and a pressurized air outlet configured to apply pressurized air toward the material sheet to press the material sheet against the corrugated surface and thereby crimp the material sheet, wherein the corrugated surface has a waveform substantially aligned with the direction of movement of the material sheet.

[0011] According to another aspect of the present invention, a method for crimping a material sheet is provided, the method comprising passing the material sheet over a corrugated surface and pressing the material sheet against the corrugated surface with pressurized air to crimp the material sheet, the corrugated surface having a waveform substantially aligned with the direction of movement of the material sheet.

[0012] In contrast to existing systems in which a material sheet is crimped between a pair of corrugated rollers, embodiments of the present disclosure enable the crimping of a material sheet by using pressurized air to press the material sheet against a single corrugated surface. Using pressurized air to apply a pressing force to the material sheet against a corrugated surface allows for greater and faster control of the crimping process because the magnitude of the pressing force can be easily adjusted by changing the flow of pressurized air from the pressurized air outlet.

[0013] In existing systems, adjusting the spacing or relative alignment of a pair of crimp rollers can be extremely difficult, especially during operation. Inaccurate spacing or relative alignment of a pair of crimp rollers can result in poorly crimped material sheets or crimped material sheets with unwanted cuts or tears. If the material sheet is a strip of material unwound from a bobbin, it may take some time for technicians to notice a problem with a pair of crimp rollers. By the time the problem is noticed, it is often necessary to stop the manufacturing process to adjust the crimp rollers, resulting in costly downtime. Furthermore, by the time the problem is noticed, a large number of defective products may have already been manufactured, which must be separated from the satisfactory product flow and discarded, resulting in unnecessary waste.

[0014] Embodiments of this disclosure enable dynamic and reactive adjustment to the pressing force on a material sheet to correct defects such as excessive or insufficient crimping without interrupting the manufacturing process. This can lead to a reduction in waste.

[0015] The corrugated surface may be formed on a substantially flat substrate. For example, the corrugated surface may be formed on the surface of a substantially flat plate, and the material sheet may be pressed against the corrugated surface of the plate by pressurized air.

[0016] A corrugated surface may be formed on a curved substrate. For example, a corrugated surface may be formed on the surface of a curved plate. The surface of the curved plate may have a curvature defined by a conical section. For example, the surface of the curved plate may extend through an arc of one of a circle, an ellipse, a parabola, and a bicircle. The surface of the curved plate may extend through other curvatures.

[0017] The corrugated surface may be formed on the circumferential surface of a substantially cylindrical substrate. The substrate may be formed as a substantially cylindrical drum. The corrugated surface may extend over the entire circumferential surface. The corrugated surface may extend over only a portion of the circumferential surface.

[0018] A corrugated surface may be formed on the outer surface of the endless belt. In embodiments in which a material sheet moves through the apparatus, the endless belt may pass through a pair of cylindrical rollers to allow the surface of the endless belt to move together with the material sheet. This may help reduce undesirable wear or heating due to friction between the material sheet and the corrugated surface.

[0019] The corrugated surface may be configured to remain stationary relative to the material sheet. This can simplify the structure and operation of the device.

[0020] The corrugated surface may be configured to move together with the material sheet in the direction of movement of the material sheet. This can help reduce undesirable wear or heating due to friction between the material sheet and the corrugated surface.

[0021] The corrugated surface may be configured to move at substantially the same speed as the material sheet where the material sheet is pressed against the corrugated surface. This can help reduce undesirable wear or heating due to friction between the material sheet and the corrugated surface.

[0022] The corrugated surface may be configured to move at a slower speed than the material sheet where the material sheet is pressed against it. This can help reduce excessive wear or heating due to friction between the material sheet and the corrugated surface, while promoting the formation of crimped corrugations within the material sheet due to the relative movement between the material sheet and the corrugated surface.

[0023] The corrugated surface has a waveform substantially aligned with the direction of movement of the material sheet. This can allow the material sheet to move continuously along the corrugated surface while being crimped.

[0024] The material sheet may include strips of material that are unwound from the bobbin before passing over the corrugated surface. This allows for a substantially continuous crimping process until at least all of the material strips have been unwound and a new bobbin needs to be attached.

[0025] The pressurized air outlet may be configured to apply pressurized air directly onto the material sheet, pressing the material sheet against the corrugated surface. To avoid undesirable localized pressure concentrations and to obtain uniform crimp across the entire material sheet, the pressurized air outlet may include multiple jets configured to apply substantially uniform air pressure across the width of the material sheet. The multiple jets may be configured to generate overlapping cones of pressurized air. The pressurized air outlet may also include at least one flat air jet configured to generate a substantially linear fan of pressurized air across the width of the sheet material.

[0026] The pressurized air outlet may be configured to apply pressurized air to the intervening surface and then press the material sheet against the corrugated surface. In this way, it may be possible to press the material sheet more uniformly against the corrugated surface. In this way, it may be possible to reduce the risk of puncturing the material sheet with locally concentrated jets of pressurized air.

[0027] The intervening surface may be a flexible sheet. The flexible sheet may allow the intervening surface and the underlying material sheet to conform more closely to the corrugated surface when pressurized air is applied.

[0028] The flexible sheet may be configured as an endless belt. The endless belt may pass through at least one drive roller. The endless belt may pass through at least two drive rollers. The pressurized air outlet may be disposed within the peripheral portion of the endless belt such that pressurized air is directed at a portion of the endless belt to press the portion of the endless belt and the material sheet against the corrugated surface. In this way, the flexible sheet may be configured to move with the material sheet as the material sheet passes through the apparatus, thereby reducing undesirable wear or heating due to friction between the flexible surface and the material sheet.

[0029] The pressurized air outlet may comprise at least one air jet.

[0030] The air jet may be a flat air jet configured to generate a substantially linear fan of pressurized air. The substantially linear fan of pressurized air may be oriented transverse to the direction of movement of the sheet material. The substantially linear fan of pressurized air may be oriented substantially perpendicular to the direction of movement of the sheet material. Generating a substantially linear fan of pressurized air may help avoid undesirable local concentrations of very high air pressures that could punch holes in the material sheet. The substantially linear fan of pressurized air may promote a substantially uniform curling across the width of the material sheet.

[0031] The air jets may be round air jets configured to generate a substantially conical flow of compressed air. It is preferable that multiple air jets are provided. The multiple air jets may be arranged in a single row across the direction of movement of the material sheet. The multiple air jets may be arranged in two or more rows across the direction of movement of the material sheet. The multiple air jets may be arranged in an array. The array may be a one-dimensional array. The array may be a two-dimensional array. Multiple round air jets arranged in this manner may help avoid undesirable localized concentrations of very high air pressure that could puncture the material sheet. Multiple round air jets arranged in this manner may promote substantially uniform crimping across the width of the material sheet. Multiple round air jets may be configured to generate overlapping cones of pressurized air.

[0032] The air jet may be controllable to apply different air pressures to different areas of the material sheet on the corrugated surface. This may provide better control over the crimping of the material sheet. The air jet may be controllable to apply lower air pressure to the rear portion in the direction of movement of the material sheet on the corrugated surface and higher air pressure to the front portion in the direction of movement of the material sheet on the corrugated surface. The air jet may be controllable to apply progressively increasing air pressure from the rear portion in the direction of movement of the material sheet on the corrugated surface to the front portion in the direction of movement of the material sheet on the corrugated surface. In this way, once the material sheet is at least partially fitted to the corrugated surface, lower air pressure is used at the rear portion in the direction of movement and higher pressure is used at the front end in the direction of movement to initiate the crimping process. This may help reduce the risk of the material sheet unnecessarily tearing or puncturing due to abrupt changes in the applied air pressure.

[0033] The air jet may be configured to apply substantially uniform air pressure across the corrugated surface of the material sheet. This can help promote uniform crimping of the material sheet.

[0034] A pressurized air outlet, such as an air jet, may be positioned at a distance of 1 cm to 30 cm, preferably 5 cm to 15 cm, from the material sheet on the corrugated base.

[0035] The corrugated surface may have substantially regular periodic waveforms. This may be advantageous when a material sheet with a regularly periodic crimp pattern is required. The waveforms on the corrugated surface do not all have the same periodicity. This may be preferable when a material sheet with an irregular or changing periodic crimp profile is required. Depending on the desired crimp profile, the corrugated surface may have waveforms of a constant depth or waveforms of different depths.

[0036] The corrugated surface may have shallower waves in the rear portion in the direction the material sheet moves along the corrugated surface, and deeper waves in the front portion in the direction the material sheet moves along the corrugated surface. This may help reduce the likelihood of the material sheet unnecessarily tearing or puncturing due to large and abrupt deformation of the material sheet relative to the corrugated surface.

[0037] In general, in a prior art system where the material sheet passes through a tangential nip point between two adjacent, interlocking crimp rollers, the material sheet is in contact with the corrugated surface for a longer period than usual, making it possible to modify several parameters of the material sheet during the crimping process. For example, the material sheet may be heated or cooled. For example, the material sheet may be humidified or dehumidified.

[0038] The corrugated surface may be equipped with a heater for heating the material sheet when pressed onto the corrugated surface. Applying heat to the material sheet can help make the material sheet more flexible or more plastically deformable, thereby facilitating the application of a crimp pattern to the material sheet.

[0039] Alternatively, or additionally, the corrugated surface may be equipped with a cooler for cooling the material sheet when pressed onto the corrugated surface. This may also help to fix the applied crimp pattern to the material sheet so that the applied crimp pattern is better maintained after the material sheet leaves the corrugated surface.

[0040] Naturally, the application of heat, cooling, or both to fix the applied crimp pattern may depend on the type of sheet material being crimped.

[0041] An air heater may be provided to heat the air before it is discharged from the pressurized air outlet. The air heater may be an electrically resistive heater. An air cooler may be provided to cool the air before it is discharged from the pressurized air outlet. The air cooler may be a thermoelectric cooler. Heating or cooling the air helps to heat or cool the material sheet when it is pressed against a corrugated surface, which may help to fix the applied crimp pattern to the material sheet.

[0042] An air humidifier may be provided to humidify the air before it is discharged from the pressurized air outlet. An air dehumidifier may be provided to dehumidify the air before it is discharged from the pressurized air outlet. Depending on the composition of the material sheet, humidifying or dehumidifying the pressurized air may help to fix the applied crimp pattern to the material sheet so that the crimp pattern applied is maintained after the material sheet leaves the corrugated surface.

[0043] A supply of additives to be added to the pressurized air may be provided before or after the pressurized air is discharged from the pressurized air outlet. In this way, the additives may be applied to the material sheet by the pressurized air. The additives may include flavoring additives to impart a desired flavor to the material sheet. The additives may include aromatherapy additives to impart a desired aroma to the material sheet. The additives may be configured such that when applied to the material sheet, the crimped material sheet is incorporated into an aerosol generator and released when exposed to heat. In this way, it may be possible to use pressurized air to crimp the material sheet and to apply the flavoring or aromatherapy additive in a single step.

[0044] The air may be pressurized so as to be applied toward the material sheet at a pressure of at least 500 kPa. For example, the air may be pressurized so as to be applied toward the material sheet at a pressure of at least 500 kPa and 10 MPa or less, or at least 700 kPa and 7 MPa or less. The pressure may be determined at the pressurized air outlet or at a point just outside each pressurized air outlet.

[0045] The sheet material may be a sheet of tobacco cast leaf material. The sheet material may be a sheet of polylactic acid material. The sheet material may be a sheet of paper material. The sheet material may be a sheet of cellulose acetate material. The sheet material may be a sheet of fibrous material. The sheet material may be made from other materials as needed.

[0046] A controller may be provided that is configured to control the pressure of the pressurized air applied by the pressurized air outlet.

[0047] A sensor may be provided which is configured to sense the parameters of the material sheet after the material sheet has been crimped.

[0048] At least one sensor may be configured to send a signal to the controller in response to a sensed parameter of the material sheet, allowing the controller to adjust the pressure of the pressurized air applied by the pressurized air outlet.

[0049] This may provide a feedback control system that allows for the dynamic adjustment of the pressure of pressurized air applied to a material sheet in response to detected changes in a sensed parameter.

[0050] For example, at least one sensor may be configured to detect unwanted holes or tears in the material sheet, and the controller may be configured to reduce the pressure of the pressurized air applied by the pressurized air outlet when a hole or tear in the material sheet is detected by at least one sensor.

[0051] Alternatively, or additionally, at least one sensor may be configured to sense the crimp depth within the material sheet, and the controller may be configured to increase the pressure of the pressurized air applied by the pressurized air outlet when the sensed crimp depth within the material sheet falls below a predetermined value.

[0052] As used herein, the term “wavy” is used to describe a surface shaped to have a series of generally parallel ridges and grooves.

[0053] As used herein, the term “crimp” is used to describe the process of processing a material sheet to form a crimped material sheet having multiple ridges or bumps and grooves.

[0054] As used herein, the term “pressurized air” refers to air (or other suitable non-toxic gas) that has been pressurized to a predetermined pressure substantially greater than standard atmospheric pressure. For example, pressurized air may refer to air at a pressure of at least 500 kPa.

[0055] As used herein, the term “pressurized air outlet” refers to an outlet such as a nozzle or jet that is operated to deliver pressurized air to a surface in a controlled manner and with predictable pressure characteristics in a defined direction.

[0056] As used herein, the term “material sheet” refers to a layered element having a width and length substantially greater than its thickness. The material sheet preferably has a width of 5 cm to 30 cm, optionally 10 cm to 20 cm, and in some embodiments, about 12.5 cm. The material sheet preferably has a thickness of 50 μm to 500 μm, optionally 100 μm to 400 μm, optionally 150 μm to 350 μm, optionally 175 μm to 275 μm, optionally 200 μm to 250 μm, and optionally about 215 μm. The length of the material sheet is not particularly important in the context of this disclosure. Generally, the material sheet is unwound from a bobbin and can be tens or hundreds of meters long.

[0057] As used herein, the terms “upstream” and “downstream” are used to describe the relative positions of components of an apparatus or steps of a method, with reference to the direction of movement of the material sheet. [Brief explanation of the drawing]

[0058] [Figure 1] Figure 1 shows the arrangement of crimp rollers in the conventional technology. [Figure 2] Figure 2 shows the first pattern of circumferential grooves on a pair of meshed conventional crimping rollers. [Figure 3] Figure 3 shows a second pattern of circumferential grooves on a pair of meshed conventional crimping rollers. [Figure 4] Figure 4 shows a first embodiment having a material sheet pressed against a substantially flat corrugated surface of a substrate by pressurized air applied through a pressurized air outlet. [Figure 5]Figure 5 shows a second embodiment having a material sheet pressed against the corrugated surface of a curved substrate by pressurized air applied through a pressurized air outlet. [Figure 6] Figure 6 shows a third embodiment having a material sheet that is pressed against a corrugated surface formed on the outer surface of the endless belt by pressurized air applied by a pressurized air outlet. [Figure 7] Figure 7 shows a fourth embodiment in which the material sheet is pressed against a corrugated surface by pressurized air applied through a plurality of pressurized air outlets arranged along a line transverse to the direction of movement of the material sheet. [Figure 8] Figure 8 shows details of the fourth embodiment of Figure 7. [Figure 9] Figure 9 shows a fifth embodiment in which the material sheet is pressed against a corrugated surface by pressurized air applied through a plurality of pressurized air outlets arranged in two generally parallel lines that transverse the direction of movement of the material sheet. [Figure 10] Figure 10 shows a sixth embodiment having an intervening surface in the form of an endless belt running between a pressurized air outlet and a material sheet on a corrugated surface. [Figure 11] Figure 11 shows a detailed example of a waveform surface. [Figure 12] Figure 12 is a flowchart showing the control process of an embodiment of the present disclosure. [Figure 13] Figure 13 shows details of the two pressurized air outlets in the pressurized air outlet array and illustrates the combined effect of the two pressurized air outlets. [Modes for carrying out the invention]

[0059] [Examples] The present invention is defined in the claims. However, a non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of any of the features described above, for example, one or more features of other embodiments, forms, or aspects described herein.

[0060] Example 1: An apparatus for crimping a material sheet, comprising: a corrugated surface; a conveying mechanism through which the material sheet passes; and a pressurized air outlet configured to apply pressurized air toward the material sheet so as to press the material sheet against the corrugated surface and thereby crimp the material sheet. Example 2: The apparatus according to Example 1, wherein the pressurized air outlet is positioned at a distance of 1 cm to 30 cm, preferably 5 cm to 15 cm, from the material sheet on the corrugated surface. Example 3: The apparatus according to Example 1 or 2, wherein the corrugated surface is formed on a substantially flat substrate. Example 4: The apparatus according to Example 1 or 2, wherein a corrugated surface is formed on a curved substrate. Example 5: The apparatus according to Example 1 or 2, wherein the corrugated surface is formed on the circumferential surface of a substantially cylindrical substrate. Example 6: The apparatus according to Example 1 or 2, wherein a corrugated surface is formed on the outer surface of an endless belt. Example 7: The apparatus according to any one of Examples 1 to 5, wherein the corrugated surface is configured to remain stationary relative to the material sheet. Example 8: The apparatus according to any one of Examples 1 to 6, wherein the corrugated surface is configured to move together with the material sheet along the direction of movement of the material sheet. Example 9: The apparatus according to Example 8, wherein the corrugated surface is configured to move at substantially the same speed as the material sheet at the point where the material sheet is pressed against the corrugated surface. Example 10: The apparatus according to Example 8, wherein the corrugated surface is configured to move at a lower speed than the material sheet at the point where the material sheet is pressed against the corrugated surface. Example 11: The apparatus according to any one of Examples 1 to 10, wherein the corrugated surface has a waveform substantially aligned with the direction of movement of the material sheet. Example 12: The apparatus according to any one of Examples 1 to 11, comprising a material sheet and a strip of material unwound from a bobbin before passing over a corrugated surface. Example 13: The apparatus according to any one of Examples 1 to 12, wherein the pressurized air outlet is configured to apply pressurized air directly onto the material sheet so as to press the material sheet against the corrugated surface. Example 14: The apparatus according to any one of Examples 1 to 13, further comprising a supply of additives and configured to add additives to pressurized air so as to apply the additives to a material sheet. Example 15: The apparatus according to Example 14, wherein the additive is a flavor additive or an aroma additive. Example 16: The apparatus according to any one of Examples 1 to 12, wherein the pressurized air outlet is configured to apply pressurized air to an intervening surface that presses the material sheet against the corrugated surface. Example 17: The apparatus according to Example 16, wherein the intervening surface is a flexible sheet. Example 18: The apparatus according to Example 17, wherein the flexible sheet is configured as an endless belt. Example 19: The apparatus according to Embodiment 18, wherein the endless belt passes through at least one drive roller. Example 20: The apparatus according to Example 19, wherein the endless belt passes through at least two drive rollers. Example 21: The apparatus according to any one of Examples 18 to 20, wherein the pressurized air outlet is located within the periphery of the endless belt so that the pressurized air is directed to a portion of the endless belt in order to press the portion of the endless belt and the material sheet against the corrugated surface. Example 22: The apparatus according to any one of Examples 1 to 21, wherein the pressurized air outlet includes at least one air injection. Example 23: The apparatus according to Example 22, wherein the air injection is a flat air injection configured to produce a substantially linear fan of pressurized air. Example 24: The apparatus according to Example 23, wherein a substantially linear fan of pressurized air is oriented transversely to the direction of movement of the sheet material. Example 25: The apparatus according to Example 23 or 24, wherein a substantially linear fan of pressurized air is oriented substantially perpendicular to the direction of movement of the sheet material. Example 26: The apparatus according to Example 22, wherein the air injection is a round air injection configured to generate a substantially conical flow of compressed air. Example 27: The apparatus according to any one of Examples 22 to 26, comprising multiple air injections. Example 28: The apparatus according to Example 27, wherein multiple air jets are arranged in a line across the direction of movement of the material sheet. Example 29: The apparatus according to Example 27, wherein multiple air jets are arranged in two or more rows across the direction of movement of the material sheet. Example 30: The apparatus according to Example 27, wherein multiple air jets are arranged in an array. Example 31: The apparatus according to Example 30, wherein the array is a one-dimensional array. Example 32: The apparatus according to Example 30, wherein the array is a two-dimensional array. Example 33: The apparatus according to any one of Examples 27 to 32, wherein the air jet can be controlled to apply different air pressures to different areas of a material sheet on a corrugated surface. Example 34: The apparatus according to Example 33, wherein the air jet can be controlled to apply lower air pressure in the rear portion in the direction in which the material sheet moves on the corrugated surface, and higher air pressure in the front portion in the direction in which the material sheet moves on the corrugated surface. Example 35: The apparatus according to Example 33, wherein the air jet can be controlled to apply progressively increasing air pressure from the rear portion in the direction in which the material sheet moves on the corrugated surface to the front portion in the direction in which the material sheet moves on the corrugated surface. Example 36: The apparatus according to any one of Examples 27 to 32, wherein the air jet is configured to apply substantially uniform air pressure across a corrugated surface material sheet. Example 37: The apparatus according to any one of Examples 1 to 36, wherein the waveform surface has a substantially regular periodic waveform. Example 38: The apparatus according to any one of Examples 1 to 36, wherein the waveform surface does not necessarily have waveforms with the same periodicity. Example 39: The apparatus according to any one of Examples 1 to 38, wherein the corrugated surface has a waveform of a certain depth. Example 40: The apparatus according to any one of Examples 1 to 38, wherein the corrugated surface has corrugations of different depths. Example 41: The apparatus according to any one of Examples 1 to 38, wherein the corrugated surface has a shallower waveform in the rear portion in the direction in which the material sheet moves on the corrugated surface, and a deeper waveform in the front portion in the direction in which the material sheet moves on the corrugated surface. Example 42: The apparatus according to any one of Examples 1 to 41, wherein the corrugated surface is equipped with a heater for heating a material sheet when pressed onto the corrugated surface. Example 43: The apparatus according to any one of Examples 1 to 42, wherein the corrugated surface is equipped with a cooler for cooling a material sheet when it is pressed onto the corrugated surface. Example 44: The apparatus according to any one of Examples 1 to 43, further comprising an air heater for heating the air before it is discharged from the pressurized air outlet. Example 45: The apparatus according to any one of Examples 1 to 44, further comprising an air cooler for cooling the air before it is discharged from a pressurized air outlet. Example 46: The apparatus according to any one of Examples 1 to 45, further comprising an air humidifier for humidifying the air before it is discharged from the pressurized air outlet. Example 47: The apparatus according to any one of Examples 1 to 46, further comprising an air dehumidifier for dehumidifying the air before it is discharged from a pressurized air outlet. Example 48: The apparatus according to any one of Examples 1 to 47, configured to pressurize air applied toward a material sheet at a pressure of at least 500 kPa. Example 49: The apparatus according to any one of Examples 1 to 47, configured to pressurize the air applied toward the material sheet at a pressure of at least 500 kPa and 10 MPa or less. Example 50: The apparatus according to Example 49, configured to pressurize the air applied toward the material sheet at a pressure of at least 700 kPa and 7 MPa or less. Example 51: The apparatus according to any one of Examples 1 to 50, wherein the sheet material is a sheet selected from the group consisting of tobacco cast leaf material, polylactic acid material, paper material, cellulose acetate material, and fibrous material. Example 52: The apparatus according to any one of Examples 1 to 51, further comprising a controller configured to control the pressure of pressurized air applied by a pressurized air outlet, and at least one sensor configured to sense parameters of a material sheet after the material sheet has been crimped, wherein at least one sensor is configured to transmit a signal to the controller, enabling the controller to adjust the pressure of pressurized air applied by the pressurized air outlet in response to the sensed parameters of the material sheet. Example 53: The apparatus according to Example 52, wherein at least one sensor is configured to detect unwanted holes or tears in the material sheet, and the controller is configured to reduce the pressure of the pressurized air applied by the pressurized air outlet when a hole or tear in the material sheet is detected by at least one sensor. Example 54: The apparatus according to Example 52 or 53, wherein at least one sensor is configured to sense the crimp depth within a material sheet, and a controller is configured to increase the pressure of the pressurized air supplied by the pressurized air outlet when the sensed crimp depth within the material sheet falls below a predetermined value. Example 55: A method for crimping a material sheet, comprising: passing the material sheet through a corrugated surface; and pressing the material sheet against the corrugated surface with pressurized air in order to crimp the material sheet. Example 56: The method according to Example 55, wherein pressurized air is output from an outlet located at a distance of 1 cm to 30 cm, preferably 5 cm to 15 cm, from the material sheet on the corrugated surface. Example 57: The method according to Example 55 or 56, wherein the corrugated surface is formed on a substantially flat substrate. Example 58: The method according to Example 55 or 56, wherein the corrugated surface is formed on a curved substrate. Example 59: The method according to Example 55 or 56, wherein the corrugated surface is formed on the circumferential surface of a substantially cylindrical substrate. Example 59: The apparatus method according to Example 55 or 56, wherein a corrugated surface is formed on the outer surface of an endless belt. Example 60: The method according to any one of Examples 55 to 59, wherein the corrugated surface remains stationary relative to the material sheet. Example 61: The method according to any one of Examples 55 to 59, wherein the corrugated surface moves together with the material sheet in the direction of movement of the material sheet. Example 62: The method according to Example 61, wherein the corrugated surface moves at substantially the same speed as the material sheet at the point where the material sheet is pressed against the corrugated surface. Example 63: The method according to Example 61, wherein the corrugated surface moves at a lower speed than the material sheet at the point where the material sheet is pressed against the corrugated surface. Example 64: The method according to any one of Examples 55 to 63, wherein the corrugated surface has a waveform substantially aligned with the direction of movement of the material sheet. Example 65: The method according to any one of Examples 55 to 64, wherein the material sheet includes a strip of material, and the strip of material is unwound from the bobbin before it passes across the corrugated surface. Example 66: The method according to any one of Examples 55 to 65, wherein pressurized air is applied directly onto the material sheet so that the pressurized air outlet presses the material sheet against the corrugated surface. Example 67: The method according to any one of Examples 55 to 66, wherein an additive is added to pressurized air and applied to a material sheet by the pressurized air. Example 68: The method according to Example 67, wherein the additive is a flavoring additive or an aroma additive. Example 69: The method according to any one of Examples 55 to 66, wherein a pressurized air outlet applies pressurized air to the intervening surface, which then presses the material sheet against the corrugated surface. Example 70: The method according to Example 69, wherein the intervening surface is a flexible sheet. Example 71: The method according to Example 69, wherein the flexible sheet is an endless belt. Example 72: The method according to Embodiment 71, wherein the endless belt passes through at least one drive roller. Example 73: The method according to Embodiment 72, wherein the endless belt passes through at least two drive rollers. Example 74: The method according to any one of Examples 71 to 73, wherein the pressurized air outlet is located within the periphery of the endless belt so that the pressurized air is directed to a portion of the endless belt in order to press the portion of the endless belt and the material sheet against the corrugated surface. Example 75: The method according to any one of Examples 55 to 74, wherein the pressurized air outlet includes at least one air injection. Example 76: The method according to Example 75, wherein the air jet is a flat air jet that generates a substantially linear fan of pressurized air. Example 77: The method according to Example 76, wherein a substantially linear fan of pressurized air is oriented transversely to the direction of movement of the sheet material. Example 78: The method according to Example 76 or 77, wherein a substantially linear fan of pressurized air is oriented substantially perpendicular to the direction of movement of the sheet material. Example 79: The method according to Example 75, wherein the air injection is a circular air injection that generates a substantially conical flow of compressed air. Example 80: The method according to any one of Examples 75 to 79, wherein the pressurized air outlet includes multiple air injections. Example 81: The method according to Example 80, wherein multiple air jets are arranged in a line across the direction of movement of the material sheet. Example 82: The method according to Example 80, wherein multiple air jets are arranged in two or more rows across the direction of movement of the material sheet. Example 83: The method according to Embodiment 80, wherein multiple air injections are arranged in an array. Example 84: The method according to Example 83, wherein the array is a one-dimensional array. Example 85: The method according to Example 83, wherein the array is a two-dimensional array. Example 86: The method according to any one of Examples 80 to 85, wherein the air jet is controlled to apply different air pressures to different areas of a material sheet on a corrugated surface. Example 87: The method according to Example 86, wherein the air jet is controlled to apply lower air pressure in the rear portion in the direction in which the material sheet moves along the corrugated surface, and higher air pressure in the front portion in the direction in which the material sheet moves along the corrugated surface. Example 88: The method according to Example 86, wherein the air jet is controlled to apply progressively increasing air pressure from the rear portion in the direction in which the material sheet moves along the corrugated surface to the front portion in the direction in which the material sheet moves along the corrugated surface. Example 89: The method according to any one of Examples 80 to 85, wherein the air jet is controlled to apply substantially uniform air pressure across a corrugated surface material sheet. Example 90: The method according to any one of Examples 55 to 89, wherein the waveform surface has a substantially regular periodic waveform. Example 91: The method according to any one of Examples 55 to 89, wherein the waveform surface does not necessarily have the same periodicity. Example 92: The method according to any one of Examples 55 to 91, wherein the corrugated surface has a waveform of a certain depth. Example 93: The method according to any one of Examples 55 to 91, wherein the corrugated surface has corrugations of different depths. Example 94: The method according to any one of Examples 55 to 91, wherein the corrugated surface has a shallower waveform in the rear portion in the direction in which the material sheet moves on the corrugated surface, and a deeper waveform in the front portion in the direction in which the material sheet moves on the corrugated surface. Example 95: The method according to any one of Examples 55 to 94, wherein the corrugated surface includes a heater for heating a material sheet when it is pressed onto the corrugated surface. Example 96: The method according to any one of Examples 55 to 95, wherein the corrugated surface is equipped with a cooler for cooling the material sheet when it is pressed onto the corrugated surface. Example 97: The method according to any one of Examples 55 to 96, wherein pressurized air is heated before pressing the material sheet against the corrugated surface. Example 98: The method according to any one of Examples 55 to 96, wherein pressurized air is cooled before pressing the material sheet against the corrugated surface. Example 99: The method according to any one of Examples 55 to 98, wherein pressurized air is humidified before pressing the material sheet against the corrugated surface. Example 100: The method according to any one of Examples 55 to 98, wherein pressurized air is dehumidified before the material sheet is pressed against the corrugated surface. Example 101: The method according to any one of Examples 55 to 100, wherein pressurized air is applied toward the material sheet at a pressure of at least 500 kPa. Example 102: The method according to any one of Examples 55 to 100, wherein pressurized air is applied to the material sheet at a pressure of at least 500 kPa and 10 MPa or less. Example 103: The method according to Example 102, wherein pressurized air is applied to the material sheet at a pressure of at least 700 kPa and 7 MPa or less. Example 104: The method according to any one of Examples 55 to 103, wherein the sheet material is a sheet selected from the group consisting of tobacco cast leaf material, polylactic acid material, paper material, cellulose acetate material, and fibrous material. Example 105: The method according to any one of Examples 55 to 104, further comprising controlling the pressure of pressurized air applied by a pressurized air outlet and sensing the parameters of the material sheet after the material sheet has been crimped, wherein the controller adjusts the pressure of the pressurized air applied by the pressurized air outlet in response to the sensed parameters of the material sheet. Example 106: The method according to Example 105, wherein the sensed parameter is the presence of an unwanted hole or tear in the material sheet, and the controller reduces the pressure of the pressurized air applied by the pressurized air outlet when a hole or tear in the material sheet is detected. Example 107: The method according to Example 105 or 106, wherein the sensed parameter is the crimp depth of the material sheet, and the controller increases the pressure of the pressurized air applied by the pressurized air outlet when the sensed crimp depth of the material sheet falls below a predetermined value.

[0061] Here, we will further describe the examples with reference to the figures.

[0062] Figure 4 shows a first embodiment in which material sheets 1 and 2 are pressed onto the corrugated surface 12 of a substantially flat substrate 14 by pressurized air 21 applied by a pressurized air outlet 20. Reference numeral 1 is used for the material sheet in its un-crimped state, and reference numeral 2 is used for the material sheet in its crimped state. Material sheets 1 and 2 move on the corrugated surface 12 in the direction of movement indicated by the arrows. Material sheet 1 can be a long strip of material unwound from a bobbin (not shown). Material sheet 1 may be a sheet of polymer material, such as polylactic acid (PLA) material. Material sheet 1 may be a sheet of homogenized tobacco or tobacco cast leaf material. Material sheet 1 may be a sheet of paper material. Material sheets may be made of other materials as needed.

[0063] The pressurized air outlet 20 applies a jet of pressurized air 21 toward the material sheet 1, conforming the material sheet 1 to the corrugated surface 12, thereby deforming the non-crimped material sheet 1 into a crimped material sheet 2. By changing the pressure of the pressurized air 21, it is possible to influence the depth of crimping or the crimping profile of the material sheet 2. For example, higher pressure tends to conform the material sheet 1 more closely to the corrugated surface 12, resulting in a crimping profile that closely matches the profile of the corrugated surface 12. Lower pressure tends to cause the material sheet 1 to not adhere as closely to the corrugated surface 12, resulting in a crimping profile that is shallower than the profile of the corrugated surface 12. The pressure of the pressurized air 21 may be dynamically adjusted to provide continuous control or adjustment of the crimping profile. The pressure of the pressurized air 21 may be adjusted in response to feedback from one or more sensors (not shown) downstream of the corrugated surface 12. A sensor may detect holes or tears in the crimped material sheet 2 resulting from overpressure of the pressurized air 21, and send the information back to a controller (not shown) to reduce the pressure of the pressurized air 21 applied by the pressurized air outlet 20. Conversely, one or more sensors downstream of the corrugated surface 12 may determine that the crimped material sheet 2 is not sufficiently crimped (for example, by checking the crimping depth of the crimped material sheet 2), and send the information back to a controller (not shown) to increase the pressure of the pressurized air 21 applied by the pressurized air outlet 20.

[0064] The corrugated surface 12 may be formed from or coated with a low-friction material, such as polytetrafluoroethylene (PTFE), to reduce friction between the material sheets 1 and 2 and the corrugated surface 12 as the material sheets 1 and 2 move across the corrugated surface 12.

[0065] The substrate 14 may be provided with heating or cooling means to provide an additional level of control over the crimping process. For example, the substrate 14 may incorporate an electric heater (not shown) or a cooling coil (not shown).

[0066] Figure 5 shows a second embodiment in which material sheets 1 and 2 are pressed against the corrugated surface 12 of a curved substrate by pressurized air 21 applied by a pressurized air outlet 20. In the illustrated embodiment, the curved substrate is configured as a single cylindrical crimping roller 10 that can rotate around the longitudinal axis C. The operating principle is similar to that described above in relation to the first embodiment, and the features of the first embodiment may be equally implemented in the second embodiment.

[0067] In the embodiment shown in Figure 5, the crimp roller 10 can rotate as the material sheets 1 and 2 move in the direction indicated by the arrows. The crimp roller 10 may be driven by a motor (not shown) or it may rotate freely. In either case, there is little to no relative sliding movement between the material sheets 1 and 2 and the corrugated surface 12, which may help reduce undesirable frictional damage to the material sheets 1 and 2. When the crimp roller 10 is driven by a motor, the rotation of the crimp roller 10 may help unwind the material sheets 1 and 2 from a bobbin (not shown), or more generally, pull the material sheets 1 and 2 through a processing station.

[0068] Figure 6 shows a third embodiment in which material sheets 1 and 2 are pressed against a corrugated surface 12 formed on the outer surface of an endless belt 11 by pressurized air 21 applied by a pressurized air outlet 20. The endless belt 11 passes over a pair of rollers 30 and 31. In this way, the material sheets 1 and 2 and the corrugated surface 12 can move together as the material sheets 1 and 2 move in the direction of movement indicated by the arrows. Both rollers 30 and 31 may rotate freely. Alternatively, one or both of the rollers 30 and 31 can be driven so that the endless belt 11 helps to move the material sheets 1 and 2 in the direction of movement. In either case, there is little to no relative sliding movement between the material sheets 1 and 2 and the corrugated surface 12, which can help reduce undesirable frictional damage to the material sheets 1 and 2.

[0069] The endless belt 11 is preferably kept under sufficient tension between the rollers 30, 31 so that it exhibits a substantially flat surface that does not deform significantly even when pressurized air 21 is applied. In this way, the application of pressurized air 21 from the pressurized air outlet 20 ensures that the material sheet 1 conforms to the corrugated surface 12, thereby deforming the un-crimped material sheet 1 into a crimped material sheet 2. The principle of operation is similar to that described above in relation to the first embodiment, and the features of the first embodiment may be equally implemented in the third embodiment.

[0070] Figure 7 shows a fourth embodiment in which the material sheets 1 and 2 are pressed against the corrugated surface 12 by pressurized air 21 applied by a plurality of pressurized air outlets 20 arranged on a line transverse to the direction of movement of the material sheets 1 and 2. The plurality of pressurized air outlets 20 are arranged along a manifold bar 22 from which pressurized air is supplied from a pressurized air source 23 along a supply line 24.

[0071] In some embodiments, the transverse width of the material sheets 1 and 2 may be 10 cm to 20 cm, for example, about 12.5 cm. In these embodiments, since the width of the material sheets 1 and 2 is not particularly large, the manifold bar 22 does not need to be very long to cover the width of the material sheets 1 and 2. Therefore, for example, the number of pressurized air outlets 20 required may be only 2 to 10 pressurized air outlets 20, or 3 to 8 air outlets 20. As a result, there is no need to manage a complex airflow to numerous pressurized air outlets 20 through the manifold bar 22.

[0072] Figure 7 shows a plurality of pressurized air outlets 20 arranged on a flat corrugated surface 12, but it will be understood that the plurality of pressurized air outlets 20 shown can be equally arranged on the corrugated surface 12 of the embodiments in Figures 5 and 6, as well as on the corrugated surface in Figure 4.

[0073] By providing multiple pressurized air outlets 20 in rows that generally transverse the direction of movement of the material sheets 1 and 2, it becomes possible to apply more uniform pressure across the entire width of the material sheets 1 and 2, or to apply different pressures to different areas across the width of the material sheets 1 and 2, thereby providing greater control over the crimping process.

[0074] Figure 8 shows in more detail the multiple pressurized air outlets 20 of Figure 7 as viewed along the line of movement. The pressurized air outlets 20 are configured as injection nozzles, each of which applies pressurized air with maximum pressure along the central direction 25 and less pressure along the angled direction 26. The area of ​​material sheets 1, 2 directly below each pressurized air outlet 20 is indicated as "Zone A" and is supplied with pressurized air with maximum pressure along the central direction 25. The area of ​​sheet material 1, 2 located between the pressurized air outlets 20 is indicated as "Zone B" and is supplied with pressurized air with less pressure along the angled direction 26. However, the area of ​​sheet material 1, 2 in Zone B is supplied with pressurized air from two adjacent pressurized air outlets 20, and the sum of the pressurized air components along the angled direction 26 of the two adjacent pressurized air outlets 20 may be substantially equal to the pressurized air pressure in Zone A. In this way, the multiple pressurized air outlets 20 arranged across the width of material sheets 1, 2 can apply substantially uniform pressure across the entire width of material sheets 1, 2. Alternatively, the pressurized air pressure applied by each of the pressurized air outlets 20 can be controlled to apply a pressure profile that varies across the width of the material sheets 1 and 2. For example, a higher pressure may be applied to the central region, a lower pressure to the edge region, or vice versa.

[0075] Figure 9 shows a fifth embodiment in which the material sheets 1, 2, and 43 are pressed against the corrugated surface 12 by pressurized air supplied by a plurality of pressurized air outlets 20 arranged in two generally parallel rows transverse to the direction of movement of the material sheets 1, 2, and 43. Additional rows of pressurized air outlets 20 may be provided as needed. This arrangement is similar in principle to the arrangements in Figures 7 and 8, but provides a greater degree of control over the crimping process.

[0076] For example, the left column of the pressurized air outlet 20 can apply pressurized air to material sheet 1 at a lower pressure so as to give material sheet 43 a crimp pattern of partial depth. The right column of the pressurized air outlet 20 can apply pressurized air to material sheet 43 at a higher pressure so as to give material sheet 2 a crimp pattern of full depth. In this way, the crimp pattern can be applied in stages along the direction of movement of material sheets 1, 2, and 43, which can help reduce the formation of unwanted holes or tears in material sheet 43 due to the un-crimped material sheet 1 conforming very abruptly to the corrugated surface 12. A larger number of columns in the pressurized air outlet 20 makes it possible to apply the crimp pattern to material sheets 1, 2, and 43 with even higher-level control.

[0077] In another embodiment, the corrugated shape on the corrugated surface 12 may be shallower below the left row of pressurized air outlets 20 and gradually deepen towards the position below the right row of pressurized air outlets 20. This may allow the crimp pattern to be applied gradually to the material sheets 1, 2, and 43 to reduce the possibility of forming unwanted holes or tears. In some embodiments, the corrugation on the corrugated surface 12 may be gradually deepened in the direction of movement of the material sheets 1, 2, and 43 and combined with a gradual increase in the pressure of the pressurized air applied by the successive rows of pressurized air outlets 20.

[0078] Figure 10 shows a sixth embodiment having an intervening surface in the form of an endless belt 40 running between a pressurized air outlet 20 (or a plurality of pressurized air outlets 20) on a corrugated surface 12 and material sheets 1, 2. Although Figure 10 shows a pressurized air outlet 20 positioned on a flat corrugated surface 12, it will be understood that the illustrated pressurized air outlet 20 (or a plurality of pressurized air outlets 20) can be equally positioned on the corrugated surface 12 of the embodiments of Figures 5 and 6, as well as on the corrugated surface of Figure 4.

[0079] The endless belt 40 can pass over a pair of rollers 32, 33, allowing it to move together with the material sheets 1, 2 as they pass over the corrugated surface 12. This can help reduce or avoid undesirable friction between the outer surface of the endless belt 40 and the material sheets 1, 2. In some embodiments, one or the other or both of the rollers 32, 33 may be driven by a motor.

[0080] When pressurized air 21 is applied to the inner surface of the lower portion of the endless belt 40 in the direction toward the material sheets 1 and 2 and the corrugated surface 12, the lower portion of the endless belt 40 presses the material sheets 1 and 2 against the corrugated surface 12 in order to apply a crimp pattern to the material sheets 1 and 2. It is preferable that the endless belt 40 is sufficiently deformable so that it can generally conform to the corrugated surface 12 when the material sheets 1 and 2 are sandwiched between the lower portion of the endless belt 40 and the corrugated surface as the pressurized air 21 is applied. For example, the intervening layer formed by the endless belt 40 may have a thickness of about 50 μm to 200 μm. In this way, the material sheets 1 and 2, which may be more delicate than the endless belt 40, are prevented to some extent from forming unwanted holes or tears in the material sheets 1 and 2 due to excessive or concentrated spraying of pressurized air 21.

[0081] In the illustrated embodiment, the endless belt 40 is shown with a relatively large slack, which allows the central portion of the lower part of the endless belt 40 to hang down toward the material sheets 1, 2 beneath the pressurized air outlet or multiple outlets 20. However, it will be understood that the endless belt 40 can pass around the rollers 32, 33 with little to no slack, as long as the lower part of the endless belt 40 can still be moved sufficiently by the pressurized air 21 applied by the pressurized air outlet or multiple outlets 20 to conform the material sheets 1, 2 to the corrugated surface 12.

[0082] Instead of the endless belt 40, the intervening surface may be configured as a flexible foil that does not move in the direction of movement of the material sheets 1 and 2. The flexible foil may be made of a low-friction material, such as PTFE, or coated, in order to reduce friction between the material sheets 1 and 2 and the flexible foil.

[0083] Figure 11 shows an example of a corrugated surface 12 on a substrate 14. The corrugation has a height H, which may be 0.5 mm to 2 mm in some embodiments. The corrugation has a width or duration L, which may be 0.5 mm to 2 mm in some embodiments. The angle A between adjacent corrugations may be 0 degrees (if the corrugation shape has vertical walls) to 30 degrees in some embodiments. The radius R1 of the teeth of the corrugation may be 0.1 mm to 0.4 mm in some embodiments. The radius R2 of the bottom of the corrugation may be 0.1 mm to 0.4 mm in some embodiments. R1 and R2 may be the same or different. The values ​​given in this example are for illustrative purposes only.

[0084] Figure 12 is a flowchart illustrating a feedback-based control process for an embodiment of the present disclosure. The control circuit, provided, for example, in the form of a microcontroller or microprocessor, controls the pressure of the pressurized air 21 applied by a pressurized air outlet or a plurality of outlets 20. The system may be configured to start from an initial predetermined default pressure that is considered appropriate for crimping the material sheets 1, 2 against the corrugated surface 12. After the crimped material sheet 2 leaves the corrugated surface, the integrity of the crimped material sheet 2 is checked by a first sensor or a plurality of sensors. For example, the first sensor may include a light source and a photodetector for checking for holes or tears in the crimped material sheet 2. If the integrity of the crimped material sheet 2 is confirmed, the crimping depth of the crimped material sheet 2 is checked by a second sensor or a plurality of sensors. If both the first and second sensors indicate that the crimped material sheet 2 is substantially free of holes or tears and has been crimped to a sufficient crimping depth, then the default air pressure is acceptable. However, if the first sensor or multiple sensors indicate a lack of integrity in the crimped material sheet 2, a feedback signal is sent to the control circuit to reduce the applied pressure. Conversely, if the second sensor or multiple sensors indicate insufficient crimping depth in the crimped material sheet 2, a feedback signal is sent to the control circuit to increase the applied pressure.

[0085] Figure 13 shows details of two pressurized air outlets 20a and 20b in an array of pressurized air outlets, illustrating the combined effect of the two pressurized air outlets 20a and 20b. Each pressurized air outlet 20a, 20b, e.g., an air jet or air nozzle, applies pressurized air at maximum pressure in a downward direction substantially perpendicular to the material sheets 1 and 2. The pressure of the pressurized air applied to the material sheets 1 and 2 may decrease generally linearly along the horizontal (X) axis in either direction from a vertical point below each outlet 20a, 20b, and may become substantially zero at a distance D from the point below each pressurized air outlet 20a, 20b. The pressurized air outlets 20a and 20b may be spaced apart by a distance D such that the substantially zero pressure point of one outlet 20a coincides with the maximum pressure point of the adjacent outlet 20b. The pressurized air pressure at the material sheets 1 and 2 is shown on the vertical axis (P).

[0086] P(x) is the distribution of the air pressure P received by the material from outlet 20a as a function of the distance from the vertical line at the center of outlet 20a, where x=0 in Figure 13. At the vertical line at the center of outlet 20a, the air pressure received from outlet 20a is maximum, and its value is P0.

[0087] Assuming that the function P(x) is linear, as shown by the bold continuous line, we can see that when x=0, P(x) is maximum at the vertical line below outlet 20a, i.e., P(0)=P0. At a distance x0 from the vertical line below outlet 20a, the air pressure coming from outlet 20a is zero, and therefore P(x0)=0.

[0088] Therefore, the linear air pressure coming from outlet 20a as a function of distance x can be expressed as follows: P(x) = -P0 / x0 * x + P0

[0089] If an adjacent outlet 20b is provided, similar to outlet 20a, and its vertical center line is at x0, then the pressure P'(x) (thick dotted line) from outlet 20b can be expressed as a function of distance x as follows: P'(x) = P0 / x0 * x

[0090] Therefore, the total air pressure received by material sheets 1 and 2 at any distance x between the two outlets 20a and 20b is expressed as follows: Ptotal(x)=P(x)+P'(x)=-P0 / x0*x+P0+P0 / x0*x=P0

[0091] This pressure remains constant regardless of the value of x between the two adjacent continuous pressurized air outlets 20a and 20b (i.e., 0 ≤ × ≤ × 0).

[0092] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers representing amounts, quantities, percentages, etc., are understood to be modified in all cases by the term “approximately.” Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges within them, which may or may not be specifically listed herein. Thus, in this context, the figure A is understood as A ± 5%. In this context, the figure A may be considered to include a number that falls within the general standard error to the measurement of the characteristic that the figure A modifies. In some cases as used in the appended claims, the figure A may deviate by the percentage listed above, provided that the amount of deviation of A does not substantially affect the basic and novel characteristics of the claimed invention. Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges within them, which may or may not be specifically listed herein.

Claims

1. An apparatus for crimping a material sheet, the apparatus comprising: a corrugated surface; a transport mechanism for the material sheet to pass over the corrugated surface; and a pressurized air outlet configured to apply pressurized air toward the material sheet in order to press the material sheet against the corrugated surface and thereby crimp the material sheet, wherein the corrugated surface has a waveform substantially aligned with the direction of movement of the material sheet.

2. The apparatus according to claim 1, wherein the corrugated surface is formed on a substantially flat substrate.

3. The apparatus according to claim 1, wherein the corrugated surface is formed on the circumferential surface of a substantially cylindrical substrate.

4. The apparatus according to claim 1, wherein the corrugated surface is formed on the outer surface of the endless belt.

5. The apparatus according to any one of claims 1 to 4, wherein the corrugated surface is configured to move together with the material sheet along the direction of movement of the material sheet.

6. The apparatus according to any one of claims 1 to 5, further comprising supplying an additive, and configured to add the additive to the pressurized air so as to apply the additive to the material sheet.

7. The apparatus according to any one of claims 1 to 5, wherein the pressurized air outlet is configured to apply pressurized air to an intervening surface that presses the material sheet against the corrugated surface.

8. The apparatus according to any one of claims 1 to 7, wherein the pressurized air outlet includes a plurality of air injections.

9. The apparatus according to claim 8, wherein the plurality of air jets are arranged in at least one row across the direction of movement of the material sheet.

10. The apparatus according to claim 8 or 9, wherein the air jet can be controlled to apply different air pressures to different regions of the material sheet on the corrugated surface.

11. The apparatus according to any one of claims 1 to 10, wherein the corrugated surface has a shallower waveform in the rear portion in the direction in which the material sheet moves on the corrugated surface, and a deeper waveform in the front portion in the direction in which the material sheet moves on the corrugated surface.

12. The apparatus according to any one of claims 1 to 11, further comprising: a controller configured to control the pressure of the pressurized air applied by the pressurized air outlet; and at least one sensor configured to sense parameters of the material sheet after the material sheet has been crimped, wherein the at least one sensor is configured to transmit a signal to the controller so that the controller can adjust the pressure of the pressurized air applied by the pressurized air outlet in response to the sensed parameters of the material sheet.

13. A method for crimping a material sheet, the method comprising: passing the material sheet over a corrugated surface; and pressing the material sheet against the corrugated surface with pressurized air to crimp the material sheet, wherein the corrugated surface has a waveform substantially aligned with the direction of movement of the material sheet.

14. The method according to claim 12 or 13, wherein the additive is added to the pressurized air and applied to the material sheet by the pressurized air.

15. The method according to any one of claims 12 to 14, further comprising controlling the pressure of the pressurized air applied by a pressurized air outlet and sensing parameters of the material sheet after the material sheet has been crimped, wherein the controller adjusts the pressure of the pressurized air applied by the pressurized air outlet in response to the sensed parameters of the material sheet.

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