METHOD FOR WINDING PREFORMS

Abstract

A method for winding preforms for the manufacture of tampons feeds a material tape. Strips in the form of tapes are separated from this material tape and pushed into a continuously rotating winding drum by at least one drive roller in such a way that the strip is positioned between a winding fork and a guide bar such that when the winding fork moves around the guide bar, the latter pushes a section of the strip into a fork gap of the winding fork and thus enables entrainment. Also, a corresponding device carries out the method.

Claims

1. A method for winding preforms for manufacturing tampons, comprising the steps: a. feeding a material tape, in particular an endless material tape; b. separating tape-shaped material strips from the material tape; wherein a material strip is pushed 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 guide bar in such a way that when the winding fork moves around the guide bar, the latter pushes a section of the material strip into a fork gap.

2. The method of claim 1, wherein the material tape is designed as a laminate tape, further comprising the steps: a. feeding a backing material, in particular a fiber material, by means of at least one first draw roller; b. feeding a layered material, in particular a thermoplastic non-woven fabric, by means of at least one second draw roller; c. bringing together the backing material and the layered material; d. laminating a laminate tape from the backing material and the layered material, wherein the step of separating tape-shaped material strips from the material tape comprises separating strip-shaped laminate strips from the laminate tape.

3. The method of claim 1, in which the conveying winding unit is a rotating winding drum on which the winding forks are arranged radially.

4. The method of claim 2, in which the backing material is perforated, in particular in which the backing material is perforated before step c).

5. The method of claim 2, in which the layered material is perforated, in particular in which the layered material is perforated before step c).

6. The method of claim 1, wherein the separation is performed by the drive roller, in particular wherein a drive speed of the drive roller is higher than a conveying speed of the material tape on the upstream side of the drive roller.

7. The method of claim 1, wherein the winding fork passes the guide bar so that the material strip, in particular the laminate strip, is threaded between the winding fork and guide bar.

8. The method of claim 1, in which a removal thread is wrapped around the material tape, in particular the laminate tape, on the upstream side of the drive roller, in particular perpendicular to the longitudinal axis of the material tape, in particular the laminate tape.

9. The method of claim 1, wherein the material strip, in particular laminate strip is wound by a rotational movement of the winding fork after a section of the material strip, in particular the laminate strip has been pressed into the fork gap.

10. The method of claim 9, wherein the wound material strip or laminate strip is closed by a closing station.

11. The method of claim 1, wherein the guide bar performs a movement counter to the direction of rotation of the winding fork and back.

12. A device for winding preforms for manufacturing tampons for carrying out the method according to claim 1, comprising: a conveyor device for feeding in a material tape, in particular an endless material tape a separating unit for separating tape-shaped material strips from a material tape, at least one drive roller for pushing the laminate strips into a winding unit, the winding unit comprising a plurality of winding forks which are arranged in such a way that they can be guided past a guide bar which is stationary or movable with respect to the movement of the winding forks in such a way that a laminate strip pushed into the winding unit is pressed by the guide bar into a fork gap of the winding forks, and is thus received by the winding fork.

13. The device according to claim 12, wherein the material tape is designed as a laminate tape, the conveyor device comprising: a. a first draw roller for feeding a backing material, in particular a fiber material; b. a second draw roller for feeding a layered material, in particular a thermoplastic non-woven fabric; c. a laminating unit for laminating a laminate tape from the backing material and the layered material.

14. The device of claim 12, wherein the winding unit is designed as a winding drum, in particular wherein the winding unit is designed as a continuously rotatable, drum-like winding drum with radially arranged winding forks.

15. The device of claim 12, wherein the at least one drive roller is the separating unit.

16. The device of claim 14, further comprising a guide curve along which the winding fork winds up the laminate strip in its movement along the rotational radius of the winding drum.

17. The device of claim 14, wherein the winding forks are arranged on the winding drum so as to be rotatable about their own longitudinal axis.

18. The device of claim 13, wherein the device further comprises at least one respective guide roller for stabilizing the backing material, the layered material and the laminate tape, respectively.

19. The device of claim 12, wherein the guide bar is arranged stationary in the rotation radius of the winding forks on the winding drum, so that the guide bar can pass through the fork gap of the winding forks without contacting them on their rotation radius.

20. The device of claim 12, wherein the guide bar is arranged stationary in the rotation radius of the winding forks on the winding drum, so that the guide bar can pass through the fork gap of the winding forks without contacting them on their rotation radius, in particular wherein the guide bar is designed to perform a stroke.

21. The device of claim 11, wherein the winding drum comprises a closing station.

Description

DESCRIPTION OF THE DRAWINGS

[0091] Exemplary embodiments of the invention are described with reference to the following figures.

In the Drawings:

[0092] FIG. 1 shows a schematic overview of the device according to the invention;

[0093] FIG. 2 schematically shows a transfer area into a winding drum;

[0094] FIG. 3a schematically shows a winding fork approaching a laminate strip;

[0095] FIG. 3b shows the winding fork contacting the laminate strip;

[0096] FIG. 3c shows the bending of part of the laminate strip around the winding fork;

[0097] FIG. 3c shows the continuation along the radius of rotation of the winding drum;

[0098] FIG. 3d shows schematically the start of the winding process by the winding fork;

[0099] FIG. 4 shows a schematic cross section through the winding drum and the ejection drum;

[0100] FIG. 5 shows an alternative embodiment of a guide bar, and

[0101] FIG. 6 shows an alternative embodiment as a movable guide bar.

MODES OF CARRYING OUT THE INVENTION

[0102] 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 tape-like materials are brought together, welded and fed to a winding drum 16 as a laminate tape. The backing material 2 comes from a backing material roll 4, from which the backing material 2 is fed by continuous pulling. The tension on the rotatably mounted backing material roll 4 comes from a first draw roller 7.1, which exerts a tensile force on the backing material tape 2 by rotating about its axis of rotation. In the present exemplary embodiment, the first draw roller 7.1 is opposite a counter-pressure roller 7.2, between which the tape of the backing material 2 is guided. The counter-pressure roller 7.2 can also be driven, whereby in a special example two first draw rollers 7.1, 7.2 would be responsible for the necessary tension on the tape. In the present example, the backing material 2 is a wadding tape made of cotton cellulose fibers. The backing material 2 forms the main absorbent material for absorbing liquid in the later tampon.

[0103] For special applications, such as certain homeostatic or medical tampons, a swelling effect is of undesirable or secondary importance. In these examples, the backing material 2 is selected differently. In the case of medical tampons which are designed to release an active substance, the backing material can already be provided with the corresponding active substance at this point in time. It is also possible to apply the active substance to the finished tampon product to a later time. A row of guide rollers 6 can be provided along the entire conveying direction up to the winding device 16, which stabilize the tape guidance and prevent a lateral displacement of the corresponding tape. In the present example, a pair of guide rollers 6 is formed on the inflow side of the first draw roller, which ensure that the strip width is fed essentially horizontally to the first draw roller 7.1.

[0104] In addition to guide rollers 6, the tension in the tape can be ensured by means of compensating rollers 8 attached along the belt section. Adequate tape tension guarantees that the operative engagement of the drive and draw rollers conveys the corresponding tape optimally, and that the tools acting on the tape can always work on an essentially smooth tape surface. In the present example, the compensating roller 8 is arranged after the first draw roller 7.1 in the direction of travel of the tape. In this case, the compensating roller 8 can be provided with a spring, an actuator or another tape compensation means which are able to exert a corresponding restoring force on the belt.

[0105] In the present specific example, the compensating roller 8 is designed to be spring-loaded, so that it exerts a restoring force on the tape tensioned by it, which force is proportional to the spring force. The backing material 2 is conveyed further to a perforation unit 9. In the present example, this perforation unit 9 is used to punch weakening points in the backing material 2.

[0106] For this purpose, the perforation unit 9 can be provided, for example, as a toothed cylinder that has one or more cutting teeth along its radius of rotation, which correspondingly perforate the backing material 2 during the rolling movement. Alternatively, a cutting knife running at right angles to the running direction of the tape and pivoting back and forth in alternation can also be provided in order to enable the necessary weakening of the backing material 2. During the continuous supply of the backing material 2 to the perforation unit 9, a layered material 3 is reeled off from a layered material roll 5 simultaneously and continuously. Alternatively, a layered material magazine can also be provided, in which the layered material is stored in layers, such as folded like an accordion.

[0107] In the present example, the layered material 3 is a thermoplastic non-woven material which has a polyethylene/polypropylene mixture. The materials may have to be taken into account by arranging special guide rollers. In the present example, for example, an arrangement of further guide rollers 6 for the supply of the layered material 3 can take into account the elasticity of the thermoplastic non-woven of the layered material 3, which differs from the wadding tape of the backing material 2.

[0108] In the present concrete exemplary embodiment, a first guide roller 6 is arranged directly after the roll of layered material and then a tape tension lever 13 with a connected guide roller 6 is provided. This tape tension lever can be resiliently pivoted so that it helps to maintain appropriate tape tension. A second draw roller is provided for unwinding the layered material 3 from the roll of layered material 5 and conveying it in the direction of the backing material 2. Possible configurations of such draw rollers 7.1, 12 are basically known to a person skilled in the art. In a concrete example, the draw rollers 7.1, 12 can have roller circumferences that have a corresponding surface structure in order to facilitate the conveying process. A profiling of the roller surface has proven particularly useful. For example, grooves, teeth or roughening on the roller surface can facilitate the conveying process. Such configurations are known to those skilled in the art.

[0109] In the present view, the layered material 3 reaches the backing material 2 from below. However, this is not a prerequisite. It is also conceivable that the layered material 3 is guided onto the backing material 2 from above, with minor adjustments also having to be made as the process progresses. The two tapes 2, 3 are physically contacted with one another via a pressure roller 10, so that a surface of the backing material 2 is at least partially covered by the layered material 3. Following the pressure roller 10, which, in addition to driving the layered material tape through the backing material 2, can also provide a cutting device for the layered material 3, the contacted tapes 2, 3 reach the laminating unit 11.

[0110] In another embodiment, the cutting of the layered material takes place directly after the second draw roller 12 in the direction of tape travel (not shown). In the present example, the laminating unit 11 is designed to apply a corresponding amount of heat to the two tapes, so that they are materially connected by the thermoplastic softening of the layered material 3.

[0111] A laminate tape 17 that has now been created has two layers, namely a wadding layer and a thermoplastic non-woven layer. The laminate tape 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 tape 17 with the necessary force via a drive roller lever 15 and in since its rotational speed is faster than that of the conveyor roller 14.1, it generates an acceleration of a laminate tape part, which forms a laminate strip therefrom by tearing the predetermined breaking point or weakening point. This laminate strip is further processed in the winding drum 16.

[0112] The entire course of the process of the present device can take place continuously. For example, magazine-like rolls can enable a seamless transition and enable the backing materials 2 and layered materials 3 to be fed continuously as a tape.

[0113] FIG. 2 schematically shows the transition point of the laminate strips into the winding drum, the inner workings of the winding drum 16 being shown for better illustration. As previously mentioned, the laminate tape passes through the conveyor roller to the drive roller 19. The drive roller 19 is mounted by means of the drive roller lever in such a way that it can be brought into operative connection with the laminate tape. If an active connection is created, a piece of the laminate tape is cut off due to its relatively higher rotational speed around its axis of rotation and conveyed into the winding drum as a laminate strip. In the present example, the drive roller 19 is supported by a counter-pressure roller 20 that is also driven.

[0114] When it is fed into the winding drum 16, the laminate tape is guided on a running plate 43 which has a running plate recess 44 through which the counter-pressure roller 20 can come into operative connection with the laminate tape. With this roller arrangement, the laminate strip is practically pushed into the winding drum without the need for a physical mechanical lever or transfer unit to gradually convey the laminate tape into the winding drum. As a result, the winding drum 16 can also be operated continuously, and higher process speeds are possible. When the laminate strip is pushed into the winding drum 16, at least a part of its surface passes between a guide bar and a rotation radius of the winding forks 22 arranged radially along the circumference of the winding drum 16.

[0115] The winding forks 22 rotating in this drum circumference come into operative connection with the laminate strip as a result of their movement and guide this strip around the guide bar 21 by means of their own rotation. The guide bar 21 presses part of the laminate strip into a winding fork gap of the winding forks 22, as a result of which these are able to convey the laminate strip along with them. A replaceable guide curve 25 made of plastic is also provided in the winding drum, which serves as a counter surface for the winding of the laminate strips around the winding forks. The winding forks 22 rotating about their own axis are arranged on a rotary disc 24. Furthermore, the winding drum 16 can be provided with additional processing units. In the present example, a closing station is provided, for example, which closes the finished rolls by means of a thermal, material connection of the thermoplastic material, in the same way as was done with the layered material.

[0116] The guide bar 21 is arranged so that it protrudes into the radius of rotation of the winding forks on the winding drum. For this purpose, a holder for the guide bar 42 is provided in the present example, which holds the guide bar 21 by means of a web 41 perpendicular to the longitudinal direction of the laminate strips and parallel to the axis of rotation of the winding drum. The winding forks 22 can have their own drive for self-rotation and are surrounded by sleeves 23.

[0117] Alternatively, the guide bar 21 can also be arranged to be movable, for example by making the web actuable, for example to perform a stroke, so that the guide bar as a whole is able to perform a movement counter to the direction of rotation of the winding fork 22 and back.

[0118] In order to illustrate the entrainment of the laminate strips 18 by the winding forks 22, the process is shown again schematically and in simplified form in FIGS. 3a to 3d. In this case, these figures are only intended to illustrate the individual steps, without claiming to present the precise alignment of the winding forks at a specific point in time in the process.

[0119] FIG. 3a shows how the laminate strip 18 enters the effective range of the guide bar 21 and of the winding fork 22 moving 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 gap 28 in between. A rotation axis R2 of the winding fork 22 moves along the rotation radius 30 of the winding drum. In operation, the winding fork 22 is configured to rotate about its axis of rotation R2. Although a winding fork 22 with two winding fork fingers 27.1, 27.2 is shown in the present example, embodiments with more than two winding fork fingers are of course also possible. A system with three fingers is just as conceivable as an arrangement with numerous individual spikes as fingers. The guide bar 21 is arranged in the course of the rotation radius 30 such that when the winding forks 22 rotate about the rotation radius 30 while rotating about the rotation axis R2, they pass the guide bar 21 without contact it. For this purpose, the winding fork 22 can pause its self-rotation for the period of time that the winding fork needs to pass the guide bar.

[0120] In FIG. 3b, a winding fork 22 has paused its self-rotation and has already come into contact with part of the laminate strip 18 in such a way that a winding fork finger 27.2 bends part of the laminate strip around the guide bar. The rotation of the winding fork 22 about its axis of rotation R2 in the counterclockwise direction 23 is paused.

[0121] In FIG. 3c, the winding fork fingers 27.1, 27.2 are at the same level as the guide bar. The winding forks 22 are designed in relation to the guide bar 21 in such a way that one fork gap 28 is sufficient to pass the guide bar without contact. While the winding fork 22 passes the guide bar 21 without contact, in that the two winding fork fingers 27.1, 27.2 are guided around the guide bar 21 on the rotational circulation path, part of the laminate strip 18 is pressed by the guide bar 21 between the two winding fork fingers 27.1 and 27.2. The rotation of the winding fork 22 about its axis of rotation R2 in the counterclockwise direction 23 is paused.

[0122] In FIG. 3d, the winding fork 22 has passed the guide bar 21 completely. As the winding fork 22 continues to move, the laminate strip 18 is drawn further. The winding fork 22, which is now again rotating counterclockwise 23 about its axis of rotation R2, now winds the laminate strip around the winding fork fingers 27.1, 27.2 and pulls it past the guide bar 21. The laminate strip remains hanging with a loop in at least one winding fork finger 27.1. As a result, the laminate strip is completely wound up in the following further movement.

[0123] A further advantageous embodiment of the present invention is shown in FIG. 4. FIG. 4 schematically shows a cross section through a winding drum 16 and a suction drum 39 associated therewith. The winding drum 16 is mounted to be rotatable about an axis of rotation R1 by 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 in such a way that they project into an intermediate space between the winding drum and the suction drum 39. The winding forks 22 are arranged on a rotary disc 24. In corresponding depressions of the rotary disc 24 22 sleeves 23.1, 23.2 are arranged around the winding fork. In the present example, these sleeves are used to eject the finished roll from the winding fork, for example to a transfer station. In the present example, a winding fork 23.1 is shown in a retracted state and a second winding fork 23.2 is shown in an extended state. If the extended sleeve 23.2 curls around the winding fork 22, a roll formed on the winding fork 22 is ejected.

[0124] A suction drum 39, which also rotates parallel to the winding drum 16 and is positioned over the central drum axis 34 is driven by the same drum drive 31. The suction drum 39 comprises two rotary discs 35 arranged in parallel. Suction openings 33.1, 33.2 are provided on the rotary disc 35 facing the intermediate space between the suction drum 39 and the winding drum 16. Through this, an air flow by means of a blower 32 can take place via suction pipes 37.1, 37.2. In operation, the laminate strips or the rolls or already formed preforms have been provided with removal threads in the course of the tape feed. So that these retrieval threads can be kept out of the way during process operations, the suction pipes are provided in such a way that a constant suction is exerted on the rolls. The rolls therefore protrude essentially parallel to the axis of rotation R1 of the winding drum during the entire course of the process into the intermediate space between the winding drum 16 and the suction drum 39. This ensures that the removal threads do not interact undesirably with any moving parts.

[0125] FIG. 5 shows an alternative embodiment of a guide bar 21 which has a profile cross-section which has an end face with a substantially round surface. Overall, this alternative guide bar 21 is aligned as an airfoil. The position shown corresponds to the position in FIG. 3a, where the winding fork 22 enters the effective range of the guide bar 21 and the winding fork fingers 27.1, 27.2 pause the self-rotation of the winding fork in a position so that the guide bar passes without contact. A laminate strip 18 inserted in the direction of insertion of the drive roller (not shown) is located between the winding fork 22 and guide bar 21 and is then bent over and placed as a loop around a winding fork finger 27.1, so that it is wound up when the winding fork 22 resumes its self-rotation. The cross-sectional profile of the alternative guide bar 21 is designed to avoid creating a sharp edge and/or friction points with the laminate strip 18 as it is pulled away from the winding fork 22.

[0126] In FIG. 6, an exemplary embodiment with a movable guide bar 21 is shown schematically. This arrangement could analogously replace the components 21, 42 and 41 in FIG. 2.

[0127] The guide bar 21 is non-positively and positively connected to a lever bar 47 via a wedge-shaped guide bar pin 46. The lever bar 27 has a complementary groove to the guide bar pin 46 for this purpose. The guide bar is fixed with a locking screw and a clamping slot. Overall, the guide bar is thus designed to be interchangeable. This has the advantage that the guide bar can be selected and thus adapted to different calibers of winding forks with different winding fork gaps.

[0128] The lever bar 47 can be driven eccentrically via a joint 48 so that it completes a stroke. This stroke is transformed into a back and forth movement of the guide bar, wherein the back and forth can be the direction of rotation of the winding forks. Thus, a stop-less stroke can be performed, which can be synchronized with the rotational speed of the winding forks. With the present invention, a method and a device for the production of preforms, namely wound laminate strips, are shown which can be operated continuously and enable a high process quality. In particular, very high process speeds can be made possible by the device according to the invention. By doing without intermittent transfer of the laminate strips, the energy-intensive stop-and-go operation of machine parts is reduced to such an extent that wear and tear of the individual parts is reduced and maintenance intervals are shortened.

LIST OF REFERENCE NUMERALS

[0129] 1 device [0130] 2 backing material [0131] 3 layered material [0132] 4 backing material roll [0133] 5 layered material roll [0134] 6 guide roller [0135] 7.1 first draw roller [0136] 7.2 counter-pressure roller to the first draw roller [0137] 8 compensating roller [0138] 9 perforating unit [0139] 10 pressure roller [0140] 11 laminating unit [0141] 12 second draw roller [0142] 13 tape tension lever [0143] 14.1 conveyor roller [0144] 14.2 counter-pressure roller to conveyor roller [0145] 15 drive roller lever [0146] 16 winding drum [0147] 17 laminate tape [0148] 18 laminate strip [0149] 19 drive roller [0150] 20 counter-pressure roller to the drive roller [0151] 21 guide bar [0152] 21 alternative guide bar [0153] 22 winding fork [0154] 23 sleeve [0155] 24 rotary disc [0156] 25 guide plate [0157] 26 closing station [0158] 27 winding fork fingers [0159] 28 fork gap [0160] 29 direction of rotation of the winding fork [0161] 30 direction of rotation of the winding drum [0162] 31 drum drive [0163] 32 fan [0164] 33.1 suction opening [0165] 33.2 suction opening [0166] 34 drum axis [0167] 35 rotary discs of the suction drum [0168] 36 brace [0169] 37.1 suction pipe [0170] 37.2 suction pipe [0171] 38 sleeve mount [0172] 39 suction drum [0173] 40 deflection plate [0174] 41 web for guide bar [0175] 42 mount for guide bar [0176] 43 running plate [0177] 44 recess of the running plate [0178] 45 insertion direction of the drive roller [0179] 46 guide bar pin [0180] 47 lever bar [0181] 48 joint [0182] R1 axis of rotation of the winding drum [0183] R2 axis of rotation of the winding fork