Method for winding preforms

Abstract

The present invention relates to a method for winding preforms in order to produce tampons. In the method according to the invention, a material band is supplied. Band-like strips are separated from this material band and, by means of at least one drive roller (19), are pushed into a continuously rotating winding drum (16) such that the strip is positioned between a winding fork and a blade in such a way that, when the winding fork moves around the blade, the blade presses a portion of the strip into a fork spacing of the winding fork and thus allows entrainment. The present invention also relates to a corresponding device for carrying out the method according to the invention.

Description

[0001] Process for winding preforms

[0002] The present invention relates to a method for winding preforms for producing tampons from strip-like material, as well as a corresponding device for winding preforms, both according to the preamble of the characterizing claims.

[0003] Technological background

[0004] Tampons used for feminine hygiene, particularly during menstruation, essentially consist of an absorbent material, usually a viscose cotton strip, which is first wound into its characteristic, elongated shape, then pressed and formed. The preforms used to manufacture the tampons are wraps made from strips of this band-like material. The strips are generally between 150 and 350 mm long and between 30 and 60 mm wide. The materials used are generally bonded together in a material-to-material bond, usually by thermally induced lamination, in which a layer of material is thermoplastically bonded to the cotton. The resulting laminated strip is cut to the appropriate strip length and provided with a withdrawal thread before being wound into a wrap.The withdrawal thread is usually folded at a right angle to the longitudinal axis of the laminate strip before the actual winding process. In tampon production, high volumes combined with high quality requirements play a major role. The different dimensions of the cotton strip and the nonwoven strip can complicate the lamination process. Certain tampon manufacturing processes are designed to create a proximal closure of the tampon by thermoplastically bonding a projecting section of the nonwoven strip around the withdrawal thread at the distal end to the tampon surface. WO 2017 / 109166 A1 (Heege, T. et al.) describes a process for continuously providing strips of a laminate consisting of two fiber materials.The fiber materials are brought closer together at different speeds and the second fiber material, after being cut to the appropriate strip length, is accelerated to the speed of the first strip material while simultaneously thermoplastically bonding it.

[0005] Such and similar manufacturing processes for laminate strips are well known. The challenge lies in feeding the laminate strips to the subsequent processing unit without the need for an intermittently operating transfer unit. In common processes, for example, a continuously produced laminate strip is fed onto a winding needle in a stop-and-go process, which winds the laminate strip into a preform.

[0006] There is therefore a need for devices and methods for winding preforms for the production of tampons, which enable equally continuous further processing following, for example, continuous lamination and finishing of single- or multi-layer tapes.

[0007] Description of the invention

[0008] It is therefore an object of the present invention to provide a method and apparatus for winding preforms for tampon production that overcomes at least one disadvantage of the known method. In particular, a corresponding method and an associated apparatus are to be provided that enable the continuous feeding of finished material strips into a continuous tampon production line.

[0009] This problem is solved by the characterising features of the independent claims.

[0010] One aspect of the present invention is a method for winding preforms for the production of tampons. The method according to the invention comprises a series of steps. First, a material strip, in particular an endless material strip, is fed. Subsequently, band-shaped material strips are separated from the material strip.

[0011] In the method according to the invention, an isolated material strip is inserted into a continuously conveying winding unit by means of at least one drive roller in such a way that the material strip is positioned between a winding fork and a blade in such a way that, during a relative movement between the winding fork and the blade, the latter presses a section of the material strip into a fork spacing.

[0012] The method according to the invention makes it possible to connect a continuously operating winding unit directly to a continuously converting and optionally laminating feed station, without the need for an intermittent step in which, for example, one of the involved work stations must be stopped to receive the workpiece. In particular, a contact-free transfer between a strip feed station and a winding station is ensured, for example, since no transfer gripper has to take the strip from the converting station and transfer it to the winding station. Furthermore, the method according to the invention enables tampon production with quantities exceeding those previously achieved. In particular, quantities of over 140 pieces per minute are achieved, particularly preferably quantities of around 300 pieces per minute.

[0013] In the sense of the present invention, a material band can be understood, for example, as a material consisting essentially of fiber material or comprising fiber material.

[0014] For the purposes of the present invention, the fiber material can be a natural or synthetic material formed as a braid or woven fabric of fibers and threads. Fibers made of cotton or a blend of cotton and viscose filament are conventionally used in tampon production. A suitable material, for example, is a band of high-purity 100% viscose absorbent cotton.

[0015] The material strip can be single-layered or multi-layered. Multiple layers of the same material can be present in layers, or different materials can be present in layers. The material strip can also be only partially made up of multiple layers, e.g., with only partial sections having a multi-layer structure. In a particular embodiment, the material strip is a laminate strip. In this embodiment, a carrier material is fed to at least one first pull roller. The carrier material is preferably a fiber material. A layer material is also fed by means of at least one second pull roller. The layer material is preferably a thermoplastic nonwoven. The carrier material and the layer material are brought together. A laminate strip is formed by laminating the carrier material to the layer material. Strip-shaped laminate strips are separated from the laminate strip.

[0016] In this sense, the absorbent properties of a first carrier material can be particularly important. The cotton wool is preferably a high-purity bandage cotton made of 100% cotton. Alternatively, a synthetic material can serve as the fiber material. However, the fiber material is preferably a viscose material. In this alternative embodiment, the cotton wool could be a high-purity bandage cotton made of 100% viscose.

[0017] For the purposes of the present invention, the thermoplastic nonwoven fabric can be understood as corresponding nonwoven materials made of polyethylene and / or polypropylene and / or polyester, or a corresponding mixture of one or more of these plastics, or a mixture of a polyethylene and / or polypropylene and / or polyester with a fiber material. The materials can be selected so that they deform within a specific temperature range and can thus form a material bond with the carrier material.

[0018] For the purposes of the present invention, a laminate tape is created by lamination. The laminate tape is characterized in that the laminated materials have formed a material-to-material bond at least in sections, in particular over their entire contact surface. For the purposes of the present invention, a material-to-material bond can exist when the two materials are thermoplastically bonded. Alternatively and / or additionally, such a bond can also exist when the materials are glued to one another, e.g. by an adhesion layer on one or both layer materials, or are mechanically fiber-bonded to one another, e.g. by combing and / or carding. In a particular embodiment, the joining of the carrier material and the layer material comprises placing the two layers on top of one another so that at least one surface side of the carrier material is in contact with one surface side of the layer material.

[0019] In a particular embodiment, the carrier material and the layer material are present as strips, and the joining process includes a step in which the two strips are guided congruently in the longitudinal direction. Pressure rollers can be provided to facilitate the joining process.

[0020] In a particular embodiment, the joining only applies to a portion of the possible contact surface. For example, a strip with an overlapping area can be joined to the next strip, so that, for example, a portion of the thermoplastic nonwoven fabric does not rest on the fiber material, but remains as a free end. For the implementation of the inventive method, it is of secondary importance which material is on top and which is on the bottom during the joining.

[0021] In a particular embodiment, however, the carrier material is guided to a point where the carrier material and the layer material join in such a way that the layer material is guided to the carrier material from below and thus the carrier material rests on the layer material.

[0022] In a particular embodiment, the laminating of the carrier material and the layer material to form a laminate tape comprises joining these two tapes by applying energy, in particular heat.

[0023] In a particular embodiment, the lamination to form a laminate tape is carried out by means of at least one lamination roll.

[0024] In another particular embodiment, lamination takes place immediately after joining. Preferably, lamination takes place by passing the two layers, the carrier material and the layer material, between two rollers, wherein a lamination roller can be arranged opposite a counterpressure roller. Alternatively to the counterpressure roller, a counterpressure plate or a pair of opposing lamination rollers can be provided.

[0025] In a particular embodiment, the thermoplastic nonwoven fabric forming the layer material is softened by exposure to heat so that it bonds with the cellulose of the fiber material.

[0026] In a particular embodiment, the lamination roll is a heatable roll. Alternatively, sufficient heat can be applied using a hot air blower and / or infrared radiation to complete the lamination. The lamination process transforms the carrier material and the layer material into a laminate tape, which has fiber material on at least part of its surface and, for example, a thermoplastic nonwoven material on at least part of its opposite surface.

[0027] Of course, the device and method according to the invention can also be implemented with laminate bands that comprise more than two different layers, or that contain said materials multiple times. For example, two layered materials can be combined with the fiber material so that both surfaces of the resulting laminate band are at least partially covered with layered material. By laminating a laminate band made of a carrier material and a layered material, a tampon can be produced, for example, that has a more pleasant feel. The thermoplastic component, preferably a polyethylene / polypropylene blend or a polyethylene / polyester blend, can ensure improved insertion of the tampon during use.The fibers are held together better, and when the thermoplastic nonwoven fabric is placed on the outside during the subsequent winding process, it prevents the cellulose fibers from sticking together upon contact with moisture. For the purposes of the present invention, both the carrier material and the layer material can be processed as endless belts. Accordingly, the present application description distinguishes between a belt and a strip, with a belt referring to an undefined length, while a strip is limited in its longitudinal extent.

[0028] For the purposes of the present invention, a material strip or a laminate strip is a strip region limited in its longitudinal extent. In other words, for example, a strip cut to certain lengths can result in a series of laminate strips or material strips. For the method according to the invention, these strips can have a length that is influenced by the desired diameter or the desired density of the tampon to be produced. The lengths are preferably in a range of between 100 and 350 mm.

[0029] In the sense of the present invention, a winding unit can be understood as a unit which is suitable for conveying a winding fork on a circulating path and for bringing it into its own rotation over at least part of this circulating path, so that a section of a material or laminate strip pressed into a fork spacing can be wound up.

[0030] In a particular embodiment, the winding unit is designed as a winding drum. Alternatively, the winding unit can also be designed as a winding belt. In the context of the present invention, a winding drum can be understood as, for example, a unit with radially arranged winding forks. The winding forks can be moved along a circumference, for example in a direction of rotation of the winding drum, and in doing so can be set into rotation about their own longitudinal axes, at least in sections. In the context of the present invention, a roller is to be understood as a substantially cylindrical, circular, or roller-shaped arrangement which, when rotated about its axis of rotation, describes a curve along its circumference. However, rollers according to the invention do not necessarily have to have a circular cross-section. Crucial to the function of the roller is a substantially circumferential outer surface which is rotatable about a fixed point.Thus, some of the components referred to as rollers in the present invention can also be designed as circulating conveyor belts.

[0031] In a particular embodiment, the drive roller is a substantially cylindrical roller which can be driven perpendicular to its radius of rotation so that the roller receives a torque.

[0032] A particular advantage of the present invention is that the drive roller pushes the laminate strip into the winding drum. This eliminates the need for a component that must act between the continuously rotating, drum-like winding drum and the laminate strip feed. Pushing can be further improved by this drive roller, for example, by designing it with a ribbed, grooved, and / or roughened surface to improve static friction with the laminate strip, thus moving this laminate strip in a conveying direction.

[0033] Particularly preferably, the drive roller is controlled so that it rotates at a specific speed. This speed is preferably selected so that the laminate strip is accelerated into the winding drum. In particular, the laminate strip should be accelerated relative to the speed of the material or laminate strip on the inlet side of the drive roller.

[0034] Particularly preferably, the speed of the drive roller is selected such that the acceleration of the material or laminate strip into the winding drum is sufficient to position it between the blade and a rotation radius of the winding forks.

[0035] In a particular embodiment, the blade is designed as a bolt formed at right angles to the longitudinal axis of the laminate strips, in particular with a substantially cylindrical circumference. The round circumference can prevent the material or laminate strips from coming into contact with rough surfaces on the surface of the blade or from being damaged in any other way. In a further particular embodiment, the blade has a transverse profile which is designed to substantially prevent the laminate strips from roughening on the surface of the blade. For this purpose, the blade can, for example, have a transverse profile which is substantially drop-shaped or airfoil-shaped, with a rounded surface preferably formed on the end face in the direction of rotation of the winding forks.

[0036] In the process according to the invention, the winding forks can rotate around their own longitudinal axes. In doing so, they simultaneously rotate around the rotation axis of the winding drum. In a special embodiment, the winding forks pause their rotation when passing the blade. During the subsequent rotational movement along the rotation radius of the winding drum, the winding forks resume their rotation, and the material or laminate strip is wound up.

[0037] In a special embodiment, the winding fork passes the blade by passing through the center of two winding fork fingers. This particularly preferably occurs with the winding forks paused, i.e., while their rotation is paused. After passing the blade, their rotation can be resumed, and the laminate strip can be wound up.

[0038] In a special embodiment, the blade performs a movement opposite to the direction of rotation of the winding fork and back. This can be achieved, for example, by designing the blade to perform a stroke. The stroke is particularly preferably synchronized with the rotation speed of the winding forks, so that a complete stroke takes place in the time required for the winding fork to pass the blade. In this way, the blade supports the insertion of the laminate strip into the winding fork and enables faster operation by increasing the rotation speed. A further advantage of the stroke can be that the self-rotation of the winding forks can take place over a longer period of time; for example, the period in which winding can take place can be extended by threading them in earlier.In particular, the winding fork can, for example, resume its rotation earlier and begin winding the material or laminate strip. In a particular embodiment, the method according to the invention includes a weakening step in which the material strip is given a predetermined tear point. This can be achieved, for example, by the material strip undergoing a perforation step before a strip of material is separated by the drive roller.

[0039] In a particular embodiment, the method according to the invention comprises a perforation step in which the carrier material is perforated. Preferably, the carrier material is perforated before the carrier material and the layer material are combined.

[0040] In a particularly preferred embodiment, this perforation of the carrier material involves weakening the carrier material by creating a predetermined tear point. This can be achieved, in particular, by specially adapted rollers that cut recesses into the laminate tape using a toothed system.

[0041] In a particular embodiment, the layer material is also perforated. Particularly preferably, the layer material is perforated before the carrier material and the layer material are joined. Similar to the carrier material, this can be accomplished with an additional punching roller, which punches corresponding recesses into the carrier material as a later predetermined breaking point. In this particular embodiment, an additional driven roller is provided between the perforation of the layer material and the joining of the carrier material and the layer material, which accelerates the layer material with respect to the conveying speed on the inlet side of this additional drive roller. This acceleration can cause the layer material to tear off.

[0042] In a particular embodiment, the laminate belt on the inlet side of the drive roller is a continuous belt of the carrier material with spaced-apart perforations, onto which individual strips of the layer material are already laminated.

[0043] In a particular embodiment, the laminate tape is separated into laminate strips by the drive roller. The rotational speed of the drive roller can be selected such that it accelerates the laminate tape compared to the infeed conveyor speed. This causes a laminate strip to be torn from the laminate tape and separated. The desired length of the laminate strips can be continuously adjusted by a specialist through the selection and control of the drive roller, which represents a further advantage of the present invention.

[0044] In a particular embodiment of the method according to the invention, the winding fork rotates counterclockwise around its own axis. In another particular embodiment of the method according to the invention, a retrieval thread is wrapped around the material or laminate strip on the inlet side of the drive roller. This thread is preferably wrapped at a right angle to the longitudinal axis of the material or laminate strip.

[0045] In another particular embodiment, the material or laminate strip is wound by continuing the rotational movement of the winding fork after a section of the material or laminate strip has been pressed into the fork gap. Winding can be performed, for example, using a guide curve along which the rotation of the winding forks winds the material or laminate strip. The guide curve can, in particular, be designed to accompany the entire winding process, and its curve radius should therefore preferably be selected so that it essentially corresponds to the length of the strip to be wound.

[0046] The winding drum preferably rotates around a horizontally oriented rotational axis. The rotation of the winding drum preferably occurs clockwise. Thus, the winding forks are moved clockwise toward the blade, while the winding forks themselves rotate counterclockwise around their rotational axis, moving around the blade in such a way that a piece of laminate strip fed between the blade and the winding fork is pulled along and subsequently wound.

[0047] In a particular embodiment, the winding fork is guided past a closing station which closes the roll. This can be a thermoplastic closure, analogous to that described above with regard to the laminate or lamination. In particular, this closure can be achieved by thermoplastically bonding a surface portion of a thermoplastic nonwoven fabric that was not placed on the fiber material during lamination but remained as a free end to the roll. Analogously and / or additionally, this can also be accomplished using another method for material-to-material bonding. Preferably, the same method is used as previously used to produce the corresponding laminate tape, e.g., a method selected from the group consisting of: combing, gluing, and felting.In the sense of the present invention, the roll can be closed by the materially bonding of the surface portion that is not in contact with the fiber material during lamination with the resulting roll.

[0048] In another special embodiment, the winding fork is guided past an “anti-telescoping module” in which any area of ​​layer material that may overlap the carrier layer is shaped in such a way that a proximal closure is achieved on the finished tampon.

[0049] The method according to the invention enables continuous, scalable production. The design of the drum allows sufficient time for the individual process steps, such as winding and / or closing, to maintain high quality. In a special embodiment, a suction force acting coaxially with the winding forks is exerted on the winding drum throughout the entire winding process. This allows, for example, a folded retrieval thread to be stabilized during the processing process. This can be achieved, for example, using suction pipes.

[0050] The method according to the invention can be easily adapted to different tampon sizes. For example, the tampon size can be controlled by controlling the separation steps. Coordinated perforations and accelerations of the drive roller make it possible to obtain strips of the desired length. At the same time, for example, the guide curve can be designed to be interchangeable so that it can be adapted to a corresponding winding length. The winding forks and the blade can also be interchanged in terms of their fork spacing and blade diameter, so that different strip haptics and thicknesses can be accommodated. A further aspect of the present invention relates to a device for winding preforms for the production of tampons. The device is preferably suitable for carrying out the method described above.

[0051] The device comprises a conveyor device for feeding a material strip, in particular an endless material strip.

[0052] It further comprises a separating unit for separating band-shaped material strips from the material band, as well as a drive roller for inserting the laminate strips into a winding unit. In a particularly preferred embodiment, the drive roller acts on the separating unit, for example, by conveying it at a speed that is higher than the speed at which the conveyor device feeds the material band.

[0053] In a particular embodiment, the material strip is designed as a laminate strip, as explained above. The device then comprises a first pull roller for feeding a carrier material, in particular a fiber material. The pull roller can be provided, for example, with teeth, serrations, and / or roughened portions, which increase the static friction of the roller with respect to the carrier material. The pull roller is driven, so that, as it rotates about its axis of rotation, it feeds the carrier material from a carrier material roll.

[0054] In a particular embodiment, a roll magazine is provided which comprises a series of carrier material rolls. When a carrier material roll runs dry, special carrier material buffers can serve to ensure that another roll is fed seamlessly, so that the continuous production process does not have to be interrupted by replacing the carrier material rolls. This can also be provided analogously for layer material rolls. The device according to the invention comprises a second pull roller for feeding a layer material, in particular a thermoplastic nonwoven. This second pull roller can be designed analogously to the first pull roller with appropriate conveying aids. The device according to the invention further comprises a lamination unit for laminating a laminate tape from the carrier material and the layer material.In a particular alternative embodiment, the roll magazine comprises at least one carrier magazine in which the carrier material is arranged in layers.

[0055] In a particular embodiment, the lamination unit is a heatable roller. Preferably, a corresponding counter-roller is also provided, which can exert pressure on the heated roller, so that a strip of carrier material and layer material guided between the two rollers is laminated to form a laminate strip.

[0056] Alternatively, lamination can also be carried out using non-heated rollers that are heated at the contact point by means of induction, e.g. an infrared radiator.

[0057] In an alternative further embodiment, the lamination takes place merely by pressing, whereby the materials of the carrier material and the layer material are designed in such a way that they can naturally form a material-to-material bond. For example, the layer material can be provided with an adhesive and / or adhesion layer that bonds to the carrier material. It would also be conceivable to induce adhesion beforehand. This can be achieved, for example, by heating a layer material before joining, e.g. using an infrared radiator, which activates adhesive properties on the layer material and / or the carrier material. Then, when joining, the two materials only need to be pressed together.

[0058] The device according to the invention further comprises a separating unit for separating band-shaped laminate strips from the laminate belt. It also comprises at least one drive roller for inserting the laminate strips into a rotatable winding drum. Possible functional configurations for the drive roller have already been described above. The drive roller can be pressed onto the laminate belt via a drive roller lever, thus ensuring optimal conveying. The drive roller lever can also simply be designed to lift the drive roller from the laminate belt when needed, in which case the laminate belt ceases to function and the belt is not inserted further into the winding drum.

[0059] In a particular embodiment, the drive roller lever is designed to perform pressure equalization. The device according to the invention further comprises a winding unit having a plurality of winding forks. These winding forks are arranged such that they can be guided past a blade that is stationary or movable with respect to the conveyance of the winding unit. This can be achieved, for example, by the blade extending from a stationary holder for the blade into the conveying space of the winding forks. Alternatively, the blade can be movably mounted, for example by providing a pivotable lever web in operative connection with a gear for holding the blade in the conveying space of the winding forks. The blade is particularly preferably designed to perform a stroke.

[0060] In a particular embodiment, the winding unit is designed as a winding drum. The winding drum has a plurality of winding forks. These winding forks are arranged such that they can be guided past a blade that is stationary or movable with respect to a rotation of the winding drum. This can be achieved, for example, by the blade extending from a stationary holder for the blade into the rotation radius of the winding forks. Alternatively, the blade can be movably mounted, for example by providing a pivotable lever web in operative connection with a gear for holding the blade in the rotation radius of the winding forks. The blade is particularly preferably designed to perform a stroke, in particular wherein the stroke comprises a movement opposite to the direction of rotation of the winding drum and back.

[0061] The rotation radii of the winding forks are designed such that a certain distance between the forks allows the blade to pass through without contact during the rotation of the winding drum. Accordingly, in the device according to the invention, the winding forks can be guided past the blade in such a way that a laminate strip inserted into the winding drum is pressed by the blade at a certain distance and thus picked up by the winding fork. The winding forks can preferably be paused in their rotation while being guided past the blade.

[0062] In a particular embodiment, a guide plate can be provided onto which the at least one drive roller pushes the material or laminate strip into the rotating winding drum. This guide plate can be provided with a recess that allows the winding forks of the guide plate to pass through. In a particular embodiment, the size of this recess in the guide plate is selected to correspond to the area of ​​the material or laminate strip placed against the blade by the winding fork.

[0063] In a particular embodiment, the at least one drive roller simultaneously serves as the separating unit for separating material or laminate strips from the material or laminate tape. Examples of how this can be implemented have already been described above in connection with the method according to the invention.

[0064] In a particular embodiment, the device according to the invention comprises a guide curve along which the winding forks can wind the material or laminate strip as they move along the rotation radius of the winding drum. This guide curve is preferably designed to be interchangeable, so that its curve radius and curve length can be adapted to the dimensions of a material or laminate strip.

[0065] In a particular embodiment, the winding forks are designed such that they can rotate about their own longitudinal axis, i.e., they can be set into self-rotation. The winding forks can preferably be driven for this purpose, particularly preferably individually driven.

[0066] For this purpose, gears can be provided, for example, which transmit the rotational movement of the winding drums to the rotation of the winding forks via a gear system. The individual winding forks are preferably designed so that they can rotate independently. This allows, for example, a pause in the rotation of the winding forks to coincide with the passage of the blade, and the rotation can then be resumed during the winding process.

[0067] In a particular embodiment, the device further comprises at least one guide roller each for stabilizing the carrier material, the layer material, and the laminate tape. To ensure constant, good tape and material tape tension, guide rollers can be provided which, on the one hand, prevent lateral displacement (i.e., displacement at right angles to the longitudinal extension of the tape), and, on the other hand, ensure the necessary tape tension by exerting a specific tensile force on the tape via springs. In a particular embodiment, the winding drum comprises an additional closing station. This additional closing station can serve to close and stabilize a roll.

[0068] In a further particular embodiment, the winding drum comprises an anti-telescoping module, as described above.

[0069] The blade is preferably designed to perform a stop-free stroke movement. In a particularly preferred embodiment, an eccentric is provided to guide the stroke. This allows the movable blade to perform the stroke at a high frequency, synchronized with the respective passage of a winding fork. It is self-evident to a person skilled in the art that all non-exclusive embodiments can be realized in any combination of inventive embodiments, for example, also through device features that result from process features, and vice versa.

[0070] The inventive method and the associated device make it possible to ensure continuous processing of material and / or laminate strips into preforms. The processes are scalable and can be carried out in continuous operation. Further advantages of the inventive device have already been outlined above or described in connection with specific embodiments. It is self-evident to a person skilled in the art that in an inventive embodiment of a method for producing tampon preforms, as well as in an inventive device, the described features can be implemented in any combination, provided they are not mutually exclusive.

[0071] The invention will now be explained in more detail below using specific exemplary embodiments and figures, without being limited to these. For the sake of simplicity, the same elements in the figures are provided with the same reference numerals. The figures schematically illustrate the inventive concepts and do not claim to be to scale.

[0072] Description of the figures Embodiments of the invention are described with reference to the following figures.

[0073] They show:

[0074] Fig. 1 shows a schematic overview of the device according to the invention;

[0075] Fig. 2 schematically shows a transfer area into a winding drum;

[0076] Fig. 3a shows schematically the approach of a winding fork to a laminate strip;

[0077] Fig. 3b the contacting of the laminate strip by the winding fork;

[0078] Fig. 3c shows the bending of a part of the laminate strip around the winding fork;

[0079] Fig. 3c the continuation along the rotation radius of the winding drum;

[0080] Fig. 3d schematically shows the beginning of the winding process by the winding fork;

[0081] Fig. 4 shows schematically a cross section through the winding drum and the ejection drum;

[0082] Fig. 5 an alternative design of a sword, and

[0083] Fig. 6 shows an alternative embodiment as a movable blade. Embodiment of the invention Fig. 1 shows schematically how a device according to the invention can be constructed. In this schematic view, a conveying movement takes place from left to right. Two strip-shaped materials are brought together, welded, and fed as a laminate strip to a winding drum 16. The carrier material 2 comes from a carrier material roll 4, from which the carrier material 2 is fed by a continuous pull. The pull on the rotatably mounted carrier material roll 4 comes from a first pull roller 7.1, which exerts a tensile force on the carrier material strip 2 by rotating about its rotation axis. In the present embodiment, the first pull roller 7.1 is opposed by a counterpressure roller 7.2, between which the strip of carrier material 2 is guided. The counterpressure roller 7.2 can also be driven, whereby in a particular example, two first tension rollers 7.1, 7.2 would be responsible for the necessary tension on the band. In the present example, the carrier material 2 is a cotton band made of cotton cellulose fibers. The carrier material 2 forms the primary absorbent material for absorbing fluid in the subsequent tampon.

[0084] For special applications, e.g. certain hemostatic or medical tampons, a swelling effect is undesirable or of secondary importance. In these examples, the carrier material 2 is selected accordingly. In medical tampons designed to release an active ingredient, the carrier material can already be provided with the corresponding active ingredient at this time. It is also possible to apply the active ingredient later to the finished tampon product. Along the entire conveying direction up to the winding device 16, a series of guide rollers 6 can be provided, which stabilize the band guide and prevent lateral displacement of the corresponding band. In the present example, a pair of guide rollers 6 is formed on the inlet side of the first pull roller, which ensure an essentially horizontal feed of the band width to the first pull roller 7.1.

[0085] In addition to guide rollers 6, belt tension can be ensured by compensating rollers 8 arranged along the belt path. Adequate belt tension guarantees that the engagement of the drive and tension rollers optimally conveys the corresponding belt, and that the tools acting on the belt can always work on a substantially smooth belt surface. In the present example, the compensating roller 8 is arranged after the first tension roller 7.1 in the belt travel direction. The compensating roller 8 can be equipped with a spring, an actuator, or another belt compensating device capable of exerting an appropriate restoring force on the belt.

[0086] In this specific example, the compensating roller 8 is spring-loaded, so that it exerts a restoring force on the belt tensioned by it, which is proportional to the spring force. The carrier material 2 is then conveyed to a perforation unit 9. In this example, this perforation unit 9 serves to punch weakened portions into the carrier material 2.

[0087] For this purpose, the perforation unit 9 can be equipped, for example, as a toothed roller having one or more cutting teeth along its rotating radius, which perforate the carrier material 2 as it rolls over it. Alternatively, a cutting blade running at right angles to the direction of travel of the strip and pivoting alternately back and forth can be provided to enable the necessary weakening of the carrier material 2. During the continuous feed of the carrier material 2 to the perforation unit 9, a layered material 3 is simultaneously and continuously unwound from a layered material roll 5. Alternatively, a layered material magazine can also be provided in which the layered material is stored in layers, e.g., folded like an accordion.

[0088] In the present example, the layer material 3 is a thermoplastic fleece comprising a polyethylene / polypropylene blend. Under certain circumstances, the materials may need to be taken into account by arranging special guide rollers. In the present example, for example, an arrangement of additional guide rollers 6 for feeding the layer material 3 can accommodate the elasticity of the thermoplastic fleece of the layer material 3, which differs from that of the cotton band of the carrier material 2.

[0089] In the present specific embodiment, a first guide roller 6 is arranged directly after the layer material roll, followed by a belt tensioning lever 13 with a connected guide roller 6. This belt tensioning lever can be spring-mounted and pivotable so that it helps maintain appropriate belt tension. A second tension roller is provided to unwind the layer material 3 from the layer material roll 5 and convey it towards the carrier material 2. Possible designs of such tension rollers 7.1, 12 are generally known to those skilled in the art. In a specific example, the tension rollers 7.1, 12 can have roller circumferences that have a corresponding surface structure in order to facilitate the conveying process. Profiling the roller surface has proven particularly useful in this case. For example, grooves, teeth or roughened areas on the roller surface can facilitate the conveying process.Such designs are known to those skilled in the art.

[0090] In the present view, the layered material 3 is applied to the carrier material 2 from below. However, this is not a requirement. It is also conceivable for the layered material 3 to be guided onto the carrier material 2 from above, although minor adjustments may also be made later in the process. A pressure roller 10 physically contacts the two strips 2, 3, so that one surface of the carrier material 2 is at least partially covered by the layered material 3. Following the pressure roller 10, which, in addition to carrying the layered material strip through the carrier material 2, may also provide a cutting device for the layered material 3, the contacted strips 2, 3 reach the lamination unit 11.

[0091] In another embodiment, the cutting of the layered material takes place directly after the second pull roller 12 in the direction of tape travel (not shown). In the present example, the lamination unit 11 is designed to apply appropriate heat to the two tapes, so that they are bonded together by the thermoplastic softening of the layered material 3.

[0092] A laminate belt 17 thus produced has two layers, namely a wadding layer and a thermoplastic nonwoven layer. The laminate belt 17 is guided via a conveyor roller 14.1 and its corresponding counter-roller 14.2 to a drive roller (not shown in this figure), which is pressed onto the laminate belt 17 with the necessary force via a drive roller lever 15. As its rotation speed is faster than that of the conveyor roller 14.1, it generates an acceleration of a laminate belt section, which enables a laminate strip to be cut from it by tearing the predetermined breaking point or weakening. This laminate strip is further processed in the winding drum 16. The entire process sequence of the present device can take place continuously. For example, magazine-shaped rollers can enable a seamless transition and a continuous belt feed of the carrier materials 2 and layer materials 3. Fig.Figure 2 schematically shows the transition point of the laminate strips into the winding drum, with the interior of the winding drum 16 shown for clarity. As previously mentioned, the laminate strip passes through the conveyor roller to the drive roller 19. The drive roller 19 is mounted by means of the drive roller lever so that it can be brought into operative connection with the laminate strip. If an operative connection is established, a piece of the laminate strip is severed due to its relatively higher rotational speed around its rotational axis and fed into the winding drum as a laminate strip. In the present example, the drive roller 19 is supported by a likewise driven counterpressure roller 20.

[0093] During insertion into the winding drum 16, the laminate strip is guided on a guide plate 43, which has a guide plate recess 44 through which the counterpressure roller 20 can engage with the laminate strip. With this roller arrangement, the laminate strip is practically pushed into the winding drum without the need for a physical, mechanical lever or a transmission unit to convey the laminate strip step by step into the winding drum. This also allows the winding drum 16 to operate continuously, and higher process speeds are possible. When the laminate strip is inserted into the winding drum 16, at least part of its surface passes between a blade and a rotation radius of the winding forks 22 arranged radially along the circumference of the winding drum 16.The winding forks 22 rotating around the circumference of the drum engage the laminate strip through their movement and guide it around the blade 21 by means of its own rotation. The blade 21 presses a portion of the laminate strip into a winding fork spacing of the winding forks 22, enabling the forks to convey the laminate strip along with it. A replaceable plastic guide curve 25 is also provided in the winding drum, which serves as a counter surface for winding the laminate strip around the winding forks. The winding forks 22, which rotate about their own axes, are arranged on a turntable 24. Furthermore, the winding drum 16 can be equipped with additional processing units. In the present example, for example, a closing station is provided, which closes the finished rolls by means of a thermally bonded connection of the thermoplastic material, similar to what took place with the layered material.

[0094] The blade 21 is arranged so that it extends into the rotation radius of the winding forks on the winding drum. For this purpose, a holder for the blade 42 is provided in the present example, which, by means of a web 41, holds the blade 21 perpendicular to the longitudinal direction of the laminate strips and parallel to the rotation axis of the winding drum. The winding forks 22 can have their own drive for their own rotation and are surrounded by sleeves 23.

[0095] Alternatively, the sword 21 can also be arranged to be movable, for example by the web being designed to be actuatable, for example to carry out a stroke, so that the sword as a whole can carry out a movement opposite to the direction of rotation of the winding fork 22 and back.

[0096] To illustrate the movement of the laminate strips 18 by the winding forks 22, the process is shown schematically and in simplified form in Figs. 3a to 3d. These figures are intended merely to illustrate the individual steps, without claiming to precisely depict the orientation of the winding forks at a specific time during the process.

[0097] Fig. 3a shows how the laminate strip 18 enters the effective range of the blade 21 and the winding fork 22, which moves along a rotation radius 30 of the winding drum. In the present example, the winding fork 22 comprises two winding fork fingers 27.1, 27.2, which define a fork spacing 28 between them. A rotation axis R2 of the winding fork 22 moves along the rotation radius 30 of the winding drum. During operation, the winding fork 22 is designed to rotate about its rotation axis R2. Although the present example shows a winding fork 22 with two winding fork fingers 27.1, 27.2, embodiments with more than two winding fork fingers are of course also possible. Thus, a system with three fingers is just as conceivable as an arrangement with numerous individual mandrels as fingers.The blade 21 is arranged along the rotation radius 30 such that, during rotation of the winding forks 22 around the rotation radius 30, during a self-rotation around the rotation axis R2, they pass the blade 21 without contact. For this purpose, the winding fork 22 can pause its self-rotation for the period of time required for the winding fork to pass the blade.

[0098] In Fig. 3b, a winding fork 22 is paused in its rotation and has already come into contact with a portion of the laminate strip 18, so that a winding fork finger 27.2 bends a portion of the laminate strip around the blade. The counterclockwise rotation of the winding fork 22 around its rotation axis R2 23 is paused.

[0099] In Fig. 3c, the winding fork fingers 27.1, 27.2 are at the same height as the blade. The winding forks 22 are designed in relation to the blade 21 such that a single fork distance 28 is sufficient to pass the blade without contact. While the winding fork 22 passes the blade 21 without contact, as the two winding fork fingers 27.1, 27.2 are guided on the rotational orbit around the blade 21, a portion of the laminate strip 18 is pressed by the blade 21 between the two winding fork fingers 27.1 and 27.2. In this position, the rotation of the winding fork 22 around its rotational axis R2 in the counterclockwise direction 23 is paused.

[0100] In Figure 3d, the winding fork 22 has completely passed the blade 21. As the winding fork 22 continues to move, the laminate strip 18 is pulled further. The winding fork 22, now rotating again counterclockwise 23 about its rotation axis R2, winds the laminate strip around the winding fork fingers 27.1, 27.2 and pulls it past the blade 21. The laminate strip remains suspended by a loop in at least one winding fork finger 27.1. As a result, the laminate strip is completely wound up in the subsequent movement.

[0101] Fig. 4 shows a further advantageous embodiment of the present invention. Fig. 4 schematically shows a cross section through a winding drum 16 and a suction drum 39 associated with it. The winding drum 16 is mounted rotatably about a rotation axis R1 via a drum drive 31 through a drum axis 34. The winding drum 16 has radially arranged winding forks 22 along its circumference. These winding forks 22 are arranged such that they protrude into a space between the winding drum and the suction drum 39. The winding forks 22 are arranged on a turntable 24. Sleeves 23.1, 23.2 are arranged around the winding fork 22 in corresponding recesses in the turntable 24. In the present example, these sleeves serve to eject the finished roll from the winding fork, e.g., to a transfer station. In the present example, one winding fork 23.1 is shown in a retracted state and a second winding fork 23.2 in an extended state. If the extended sleeve 23.2 wraps around the winding fork 22, a coil formed on the winding fork 22 is ejected.

[0102] A suction drum 39, also rotating parallel to the winding drum 16, is positioned and driven by the same drum drive 31 via the central drum axis 34. The suction drum 39 comprises two parallel rotating disks 35. The rotating disk 35 facing the space between the suction drum 39 and the winding drum 16 is provided with suction openings 33.1, 33.2. These openings allow an air flow via a blower 32 to create a suction effect via suction pipes 37.1, 37.2. During operation, the laminate strips, the rolls, or even preforms, are provided with retrieval threads along the strip feed path. To ensure that these retrieval threads can be safely kept out of the way during operation, the suction pipes are designed to exert a constant suction on the rolls.The windings therefore extend essentially parallel to the rotational axis R1 of the winding drum into the space between the winding drum 16 and the suction drum 39 throughout the entire process. This ensures that the retrieval threads do not enter into any unwanted interaction with any moving parts.

[0103] Fig. 5 shows an alternative embodiment of a blade 2T, which has a profile cross-section with an end face having a substantially round surface. Overall, this alternative blade 2T is oriented in the shape of an airfoil. The position shown corresponds to the position in Fig. 3a, where the winding fork 22 enters the effective range of the blade 2T and the winding fork fingers 27.1, 27.2 pause the rotation of the winding fork in one position, so that the blade passes through without contact. A laminate strip 18, inserted in the insertion direction of the drive roller (not shown), is located between the winding fork 22 and the blade 2T and is then bent over and placed as a loop around a winding fork finger 27.1, so that when the rotation of the winding fork 22 resumes, it is wound up.The cross-sectional profile of the alternative blade 21' is designed to form as little as possible a sharp edge and / or friction point with the laminate strip 18 when it is pulled away from the winding fork 22.

[0104] Figure 6 schematically illustrates an exemplary embodiment with a movable blade 21. This arrangement could analogously replace components 21, 42, and 41 in Figure 2.

[0105] The blade 21 is connected to a lever bar 47 via a wedge-shaped blade pin 46 in a force-locking and form-locking manner. The lever bar 27 has a groove complementary to the blade pin 46 for this purpose. The blade is secured by a locking screw and a clamping slot. Overall, the blade is thus designed to be interchangeable. This has the advantage that the blade can be adapted to different calibers of winding forks with different winding fork spacings.

[0106] The lever bar 47 is eccentrically driven via a joint 48, so that it performs a stroke. This stroke is expressed in a back-and-forth movement of the blade, whereby the back-and-forth movement can be the direction of rotation of the winding forks. This allows a stroke to be performed without impact, which can be synchronized with the rotation speed of the winding forks. The present invention provides a method and a device for producing preforms, i.e., wound laminate strips, which can be operated continuously and enables high process quality. The device according to the invention enables, in particular, very high process speeds. By eliminating the intermittent transfer of the laminate strips, the energy-intensive stop-and-go operation of machine parts is reduced to such an extent that wear on the individual parts is reduced and maintenance intervals are shortened. List of Reference Symbols

[0107] 1 device

[0108] 2 Carrier material

[0109] 3 layer material

[0110] 4 carrier material roll

[0111] 5 layer material roll

[0112] 6 Leadership role

[0113] 7.1 first pulley

[0114] 7.2 Counter pressure roller to first pull roller

[0115] 8 Compensating roller

[0116] 9 Perforation unit

[0117] 10 pressure roller

[0118] 11 Laminating unit

[0119] 12 second pulley

[0120] 13 Belt tension lever

[0121] 14.1 Conveyor roller

[0122] 14.2 Counter pressure roller to conveyor roller

[0123] 15 Drive roller lever

[0124] 16 winding drum

[0125] 17 Laminate tape

[0126] 18 laminate strips

[0127] 19 Drive roller

[0128] 20 Counter pressure roller to the drive roller

[0129] 21 Sword

[0130] 2T alternative sword

[0131] 22 twist forks

[0132] 23 sleeve

[0133] 24 turntable

[0134] 25 guide plate

[0135] 26 locking station

[0136] 27 twist fork fingers

[0137] 28 fork spacing

[0138] 29 Direction of rotation of the winding fork

[0139] 30 Direction of rotation of the winding drum

[0140] 31 Drum drive

[0141] 32 blowers

[0142] 33.1 Suction opening

[0143] 33.2 Suction opening

[0144] 34 Drum axis 35 Suction drum turntables

[0145] 36 Bracing

[0146] 37.1 Intake manifold

[0147] 37.2 Suction pipe 38 Sleeve holder

[0148] 39 Suction drum

[0149] 40 steering plate

[0150] 41 Bridge for sword

[0151] 42 Holder for sword 43 Running plate

[0152] 44 Recess of the running plate

[0153] 45 Insertion direction of the drive roller

[0154] 46 sword pin

[0155] 47 Lever bar 48 Joint

[0156] R1 Rotation axis of the winding drum

[0157] R2 Rotation axis of the winding fork

Claims

Patent claims 1. A method for winding preforms for the production of tampons, comprising the steps: a. feeding a material strip, in particular an endless material strip; b. separating strip-shaped material strips from the material strip, and characterized in that a material strip is inserted into a continuously conveying winding unit by means of at least one drive roller (19) in such a way that the material strip is positioned between a winding fork (22) and a blade (21) such that when the winding fork (22) moves around the blade (21), the blade presses a section of the material strip (18) into a fork gap (28).

2. A method according to claim 1, wherein the material tape is formed as a laminate tape (17), further comprising the steps of: a. feeding a carrier material (2), in particular a fiber material, by means of at least one first tension roller (7.1, 7.2); b. feeding a layer material (3), in particular a thermoplastic nonwoven fabric, by means of at least one second tension roller (12); c. joining the carrier material (2) and the layer material (3); d. laminating a laminate tape (17) from the carrier material (2) and the layer material (3), and wherein the step of separating tape-shaped material strips from the material tape is a separation of tape-shaped laminate strips (18) from the laminate tape (17).

3. Method according to one of claims 1 or 2, wherein the conveying winding unit is a rotating winding drum (16) on which the winding forks are arranged radially.

4. Method according to one of claims 2 or 3, wherein the carrier material (2) is perforated, in particular wherein the carrier material is perforated before step c).

5. A method according to any one of claims 2 to 4, wherein the layer material (3) is perforated, in particular wherein the layer material (3) is perforated before step c).

6. A method according to any one of claims 1 to 5, wherein the singulation is carried out by the drive roller (19), in particular by having a drive speed of the drive roller (19) that is higher than a conveying speed of the material belt on the running side of the drive roller (19).

7. Method according to any one of claims 1 to 6, wherein the winding fork passes the sword, such that the material strip, in particular the laminate strip (18), is threaded between winding fork (22) and sword (21).

8. Method according to one of claims 1 to 7, wherein a return thread is wrapped around the material strip, in particular around the laminate strip (17) on the inlet side of the drive roller, in particular perpendicular to the longitudinal axis of the material strip, in particular the laminate strip (17).

9. A method according to any one of claims 1 to 8, wherein the material strip, in particular the laminate strip (18), is wound by a rotational movement of the winding fork (22) after a section of the material strip, in particular the laminate strip (18), has been pressed into the fork spacing (28).

10. A method according to claim 9, wherein the wound material strip or laminate strip (18) is closed by a closing station (26).

11. Method according to any one of claims 1 to 10, wherein the sword performs a movement against the direction of rotation of the winding fork and back.

12. Device (1) for waving preforms for the production of tampons, in particular for carrying out a method according to claim 1, comprising: a conveying device for feeding a material strip, in particular an endless material strip; a singulation unit for singulating strip-shaped material strips (18) from a material strip (17); at least one drive roller (19) for inserting the laminate strips. (18) into a winding unit, the winding unit (16) comprising a plurality of winding forks (22) which are arranged in such a way that they can be guided past a sword (21) arranged in a fixed or movable position with respect to the movement of the winding forks in such a way that a laminate strip (18) inserted into the winding unit (16) is pressed by the sword (21) into a fork spacing (28) of the winding forks and is thus received by the winding fork (22).

13. Device according to claim 12, wherein the material belt is designed as a laminate belt (17), the conveying device comprising: a. A first pull roller (7.1, 7.2) for feeding a carrier material (2), in particular a fiber material; b. A second pull roller (12) for feeding a layer material (3), in particular a thermoplastic nonwoven fabric; c. A lamination unit (11) for laminating a laminate belt (17) from the carrier material (2) and the layer material (3).

14. Device according to one of claims 12 or 13, wherein the winding unit is designed as a winding drum (16), in particular wherein the wiggling unit is designed as a continuously rotatable, drum-like wiggling drum (16) with radially arranged winding forks (22).

15. Device according to one of claims 12 to 14, wherein the at least one drive roller (19) is the singulation unit.

16. Device according to one of claims 14 or 15, further comprising a guide curve (25) along which the winding fork (22) winds the laminate strip (18) in its movement along the radius of rotation of the winding drum (16).

17. Device according to one of claims 14 to 16, wherein the rocking forks (22) are arranged rotatably about their own longitudinal axis on the rocking drum.

18. Device according to one of claims 13 to 17, wherein the device further comprises at least one guide roller (6) for stabilizing the support material (2), the comprising layer material (3) and laminate tape (17).

19. Device according to one of claims 12 to 18, wherein the sword (21) is fixedly arranged in the rotation radius of the rocking forks (22) on the winding drum, so that the sword can pass through the fork spacing (28) of the winding forks without contact with them on their rotation radius.

20. Device according to one of claims 12 to 18, wherein the sword is movably arranged in the radius of rotation of the rocking forks (22) on the rocking drum, so that the sword can pass through the fork spacing (28) of the winding forks without contact with them on their radius of rotation, in particular wherein the sword is designed to perform a stroke.

21. Device according to one of claims 11 to 17, wherein the wobble drum comprises a closing station (26).