DE3338306A1 - Method of applying an elastic strip to predetermined, successive portions of a web of material, in particular for producing nappies, and device for carrying out the method - Google Patents

Abstract

In the production of nappies which tightly surround the legs in the put-on state, in order to provide the elastic strip required on the nappy for this purpose so that it gathers actively over its entire length, the elastic strip is firstly stretched and a piece of predetermined length is cut off said strip and, in the stretched state, is guided to the one flat side of a moving web of material, is brought into adhesive contact therewith and moved along together therewith, and finally released. By means of the method according to the invention, it is to be possible in this process to vary the spacings between individual pieces of stretched strip to be applied to the web of material in accordance with the usual sizes of nappies. For this purpose, after it has been cut from the remaining elastic strip, the stretched piece of strip is moved in the direction of the web of material at a conveying speed which is greater than the initial conveying speed for the stretching of the elastic strip. It is thus possible to determine the separation of pieces of strip to be applied to the web of material, specifically independently of the operation of stretching the strip which takes place before the pieces are cut off the elastic strip.

Description

Method for applying an elastic band

predetermined, consecutive sections of a web of material, in particular for the production of diapers, as well as device for carrying out the Procedure.

The invention relates to a method for applying an elastic Tape to predetermined, one behind the other sections of a web of material, in particular for the production of diapers, with the features of the preamble of claim 1.

A section is already known for the production of diapers an elastic band (rubber band) in the stretched state over its entire length with a material web, which is usually used to form an outer layer of a Diaper used to bind tightly. This has the advantage that the sections of the elastic band over their entire length for gathering the web of material or the diaper ply are active. So there are no ineffective ends of the off expensive material existing strip sections that are not connected to the material web are, as is the case with known diaper designs.

In a known method according to EP-A-0 066 545, this is done by Looping the web of material formed by a film achieves that with only film sections in contact with the elastic band provided with an adhesive come, in which case the tape after the adhesive has set at a point between the film sections is severed.

This known method requires a relative to be carried out Elaborate technical facility that can hardly be found in existing manufacturing machines can be subsequently integrated.

The film has both when it enters and exits the device relative to its transport movement transversely directed additional movements perform that causes the film web to slide over corresponding edges.

A method with the characteristics of Prior art part of claim 1 (US Pat. No. 4,297,157).

In this process, individual stretched sections of an elastic Tape one behind the other and at equal distances from one another with a sheet of film brought into contact.

The division, given by the distances, with which the band sections are applied to the film web, what can be used for the production of diapers different size is necessary, do not vary.

The present invention is concerned with a generic one Procedure. With its help, on the one hand, it should be possible to achieve the same results how to get there by the method of the cited US Pat. No. 4,297,157; Furthermore but should also allow the distances between the individual on the material web to be applied stretched tape sections corresponding to the usual sizes of To be able to change diapers.

In the method according to the invention, this is indicated by the Feature of claim 1 achieved.

Due to the compared to the initial conveying speed for the Stretching of the elastic band greater conveying speed with which the elastic If a cut piece of tape is conveyed in the direction of the material web, it is possible to the time at which the piece of tape meets the material web and so that the division of pieces of tape applied to them can be determined regardless of the process before the separation of the band sections from the elastic Tape taking place tape stretching.

The stretching of the tape and the feeding of the pieces of tape to the material web are thus to a certain extent to be regarded as procedural steps that are decoupled from one another. Accordingly, the inventive method compels, in contrast to the generic described above Process, not to a synchronous sequence of these process steps; rather, allowed it, the division of the band sections on the material web certain length specifications to be produced blanks, such as foil blanks for diapers, by appropriate To be able to adjust the choice of the conveying speed.

An advantageous embodiment of the method is the subject of Claim 2. This makes it possible to also use such materials for the elastic band to be able to use, which is caused by a slowing down after stretching Distinguish contraction or do not allow overstretching because it is then maximal only have to be pulled apart to the required length and in this Length can remain up to their connection with the material web or film.

Such a material is, for example, polyurethane, its cost share on a blank is less than that of one designed as a rubber strand Band section. In addition, there are processing reasons such as the security of the Bonding, as well as the possibility of recycling polyurethane One such plastic could, for example, be based on the facility for carrying out the procedure according to US-PS 4,297,157 do not process, because in this case to carry out the individual Method steps stretching the elastic band along predetermined areas of a drum circumference and with regard to the required division of the stretched pieces of tape on the material track the stretching on these drum circumferential areas has to happen, which has to be done by appropriate initial overstretching of the respective Band sections must be accomplished.

For the production of pants-type diapers for children as well as for incontinent adults are more appropriate for sealing Leg sections require two elastic pieces of tape for each diaper. For this it is favorable to proceed according to claim 3.

A device according to FIG Claim 4 suitable, wherein the conveyor elements have any suitable design and guide can have. For example, this can be done at least over a predetermined distance behind each other be provided linearly movable, according to Transfer of the stretched piece of tape to the web of material or film transversely to their conveying movement away from this and controlled back into their initial position The transverse movement can be perpendicular to the flat side of the Material path, as well as in parallel to this.

By a further development of the device according to the feature of the claim 5, the division of stretched pieces of tape on the material web of a required Adjust the length of a material cut accordingly, whereby it is favorable that the To design the device according to claim 6.

A preferred embodiment of the device is the subject of Claim 7. In this case, their components can be arranged in a small space. This offers the possibility of using the device advantageously in existing production systems to be able to integrate at a later date.

It is advantageous here to use the device according to the features of the claims 8 to 10, which allow an optimally simplified overall structure.

Finally, there is a favorable construction according to the claim 11, in that it is thereby possible to determine the arc length of the segments of the respective, by Stretching to adjust the prescribed length of the band sections to be achieved.

Further features and details of the invention are set out in the following Description of an embodiment shown in the drawing of an inventive Device for performing the method explained.

The drawing shows in a schematic representation: Fig. 1 shows a plan view of a multi-layer baby diaper, the illustration on the left shows a rectangular and the right illustration an hourglass-shaped cut, Fig. 2 is an end view of the device, with one of its segments on a Take-over station for taking over the front end of an elastic, stretched piece of tape to be processed and on a material web to be transferred tape is, Fig. 3 - 5 representations similar to FIG. 2 to illustrate the operation of the device, 6 shows, in an end view, an illustration of the drive for driving the segments of the device serving drive device.

With the aid of the device according to the invention, for example, a material web formed by a flexible material, e.g. polyethylene film, a lower liquid-impermeable film blank 10 of one in FIG. 1 has multi-layer baby diaper 12 / shown in plan view with two in parallel spacing arranged from one another and extending in the longitudinal direction of the diaper elastic Band sections 14, 16 are equipped, which in the stretched state over their entire Length are to be firmly connected to the flat side of the foil blank.

The connection with the foil can be on the one facing the absorbent body Side as well as opposite.

With reference to the rectangular basic shape shown on the left, the elastic band section in the edge of the diaper as well as appropriately offset towards the longitudinal center, with an arrangement in the immediate edge area, but still appears advantageous within the absorbent body 24.

If the basic shape of the diaper is hourglass-shaped, as shown on the right, i.e. the middle section 18 has a smaller width than the front ends 10 ', 10 " on, the lines 26, 28 delimiting these leg cutouts not being parallel to the Longitudinal center extend, but symmetrically arcuate or asymmetrical Can be curves, so the elastic band section is advantageously between the adjacent edge sections 26, 28 of the foil blank 10 and suction pads 24.

The applied in the stretched state and a length smaller than the total length of the tape pieces 14, 16 comprising the diaper gather the middle section 18 of the foil blank 10 in its edge areas, which is known to be bellows-like When putting on the diaper, grasp the ruffled edge areas gently around the thighs and create a desired seal there.

With a suitable arrangement of the elastic band section With regard to the longitudinal extension of the diaper, the measure has an optimal effect reached, i.e. the tape sections do not have to be symmetrical to the transverse center of the diaper 12 be arranged.

With a 24 is applied to the upper flat side of the foil blank 10, denotes an absorbent pad made of suitable, in particular layered material.

As can be seen from Fig. 1, the elastic band sections are 14, 16 actively involved in gathering the foil blank over its entire length, i.e. they have insignificant end sections that are functional for this are ineffective.

The embodiment of the invention described below The device brings about such an arrangement of the band sections 14, 16 the foil blank 10.

The device preferably has five axes about a common axis 30 pivotable segments 32-36, or segments which can be moved along a circular path has outer partially cylindrical segment surface 38, seen perpendicular to the plane of the drawing, such a width that on it the two tape sections 14, 16 of the baby diaper can be clamped automatically. For this purpose, for example, they can be pivoted about an axis suitable clamping members 40, 42, which are each band section 14, 16 in the end regions of the Segments arranged and for example via a stationary curve 43 for clamping and releasing the band sections are controllable.

The arc length of the segment surfaces 38 corresponds to the desired length the stretched, together on an endless film web 41 in a predetermined pitch Adhesively to be applied tape sections 14, 16. The film web 41 is after Then join the other diaper components together in a different operation divided into individual foil blanks 10, which is not shown.

A take-over station I is provided along the circular path, at which the front end 46 of two endlessly supplied elastic bands 48, for example taken over by the segment 36 and by means of the clamping members 40, 42 on its outer segment surface is determined.

Seen in the pivoting direction of the segments, the takeover station follows I, for example, an adhesive application device 50, the adhesive by means of nozzles Applies point or line to the straps 48 stretched on the segment 32. However, the film web 41 could just as well face the segment surfaces 38 on its face Side be designed to be adhesively capable in corresponding areas.

The adhesive application device 50 follows at a corresponding angular distance a tape cutting device 52, with the help of which the on the outer segment surface 38 fixed bands 48 are separable in sections.

The separating device 52, which can be designed as desired, follows at an angular distance a receiving station II, to which the segments delivered, In Fig. 1 with 14 and 16 designated band sections together on the pulleys 53, 55 guided film web 41 are transferred.

III is a release station following the takeover station II denotes on which the tape sections applied with a predetermined pitch 14, 16 provided film web 41 from the segments over a deflection roller 57 again expires to be processed into a diaper.

The segments 32-36 are driven by a common drive device 54 driven in such a way that in the area of the receiving station I the preferably in pairs Adoption of elastic band material from segment to segment continuously and the paired transfer of strip sections 14, 16 in the stretched state to the film web 41 takes place in a desired pitch.

The segments are driven by the drive device 54 for this purpose, preferably in such a way that at the same time one with stretched pieces of tape 14, 16 equipped segment arrives at the upper station II when another segment the release station III leaves again.

Furthermore, she works so that at the receiving station I each two segments adjacent to one another are moved past in order to take over continuously of elastic bands 48 to ensure these segments, and further such that after the severing of band sections 14, 16 from the endless bands 48 these are fed to the upper station II at an angular velocity, by which a desired division of the tape sections on the film web is achieved will. This angular velocity is accordingly greater than in the range between the receiving station I and the tape separator 52.

The angular velocity is between that at an intermediate station provided-en tape cutting device 52 and the transfer station II preferably continuously changeable, which, however, cannot be achieved with the drive device 54 shown is.

Such a change in the angular velocity can change the division of the band sections 14, 16 on the film web 40 accordingly.

The drive device 54 shown comprises a mounted on the axle 30, driving wheel 58 drivable by a drive pinion 56, around which e.g. a rope or a chain 60 is partially led around, which also has two deflection wheels 62, 64 is carried out on the side of the receiving station I symmetrically to one through the axis 30 passing horizontally at a radial distance from the axis 30, which is larger than the radius of the driver wheel 58.

As Fig. 6 shows, the segments 32-36 are each by means of a driver tab 66 movably connected to the rope or the chain 60, the on the by the Axis 30 through segment bisector 68 lying articulation point 70 of the driver plates 66 is on the segments at a radial distance from the axis 3, which corresponds to the Radius of the driver wheel 58 corresponds.

The assignment of the deflection wheels 62, 64 to the driver wheel 58 is made in such a way that that the angular velocity of the continuously revolving segments in the areas between the tape cutting device 52 and the transfer device II and between the release station III and the takeover station I changed in such a way that for the desired division of the band sections 14, 16 on the film web 40 is achieved and on the other hand, at the receiving station I, two segments are adjacent to each other, i.e. arrive together.

Instead of a rope or a chain, the drive device as a drive member also another longitudinal element, for example a corresponding one designed belt.

Furthermore, the drive device can also be any other suitable Have training. It is only essential that the appropriate acceleration of segments between the tape separator 52 and the top station II is achieved during their rotation in order to achieve the desired division of the band sections and also between the release station III and the takeover station I causes such a delay in angular velocity that * as above already explained, in the area of the takeover station I, two adjacent each other Run in segments.

It is also essential that the stretched strip sections 14, 16 load-bearing segments after coming into contact with the film web 40 together with this, i.e. at the same conveying speed from the transfer station II to the release station III be moved.

The structural design of the segments can be any. Instead of the sector-shaped design, these can also only be one on the Have axle 30 mounted web on which the segments are arranged.

Finally, an advantageous embodiment of the device can still consist in the arc length of the individual segments continuously variable to shape in order to adapt this to the length of the band sections in the stretched state to be able to process which are to be processed for different diaper sizes. So are for example Mini diapers, which usually have a length of 380 mm, with pieces of tape to equip, which have a length of approx. 190 mm in the stretched state. On the other hand a diaper with a maximum size of 520 mm is characterized by pieces of tape whose length in the stretched state corresponds to approx. 260 mm.

The device described works as follows: Assume that the two segments 32, 36 between the release station III and the takeover station I have approached each other in such a way that when on segment 32 two ligaments with its front end / clamped and pulled over its entire length are, the segment 36 directly to the segment 32 connects, so that the bands 48 continuously run onto segment surfaces.

The feed speed of the belts 48 is selected so that during the relative movement of the segment 32 from the take-over station I in the direction of Band separator 52 pulled the elastic bands apart to the desired length and at the point in time at which these run onto the following segment 36, too fixed at the rear end of the segment 32 on its partially cylindrical segment surface 38 will. During the movement of the segment 32 from the transfer station I to the tape cutting device 52 is applied to the two tapes 48 with the aid of the adhesive applicator 50 glue applied over their entire length, for example in a punctiform manner.

Corresponding to the above explanation, this is also the case for segment 32 Leading segment 33 has first been covered with the bands 48, with, as Fig. 4 shows that these two segments are still attached to one another in the region of the tape cutting device 52 were connected and the tapes through the tape cutting device 52 in the plane the parting line of the two segments 32, 33 have been severed together.

There are now two of the two on segment 33 Ribbons 48 stretched ribbon sections 14, 16 formed.

In the area between the tape cutting device 52 and the transfer station II, the segment 33 is moved and maintained at an increased angular velocity this speed also occurs when its band sections 14, 16 according to FIG. 3 come into contact with one flat side of the film web 41 and through a pressure generated by the segment and the deflection roller 55 with the film web 41 fixed be adhesively connected. Fig. 3 shows that there are a total of three segments, namely the segments 33, 34 and 35, are in contact with the film web 41, wherein they have an angular distance of 900 to each other and the top station II and the release station III are assigned to each other in such a way that upon arrival of segment 33 at upper station II, segment 35, release station III leaves.

From Fig. 4 the position of the two segments 32, 36 can be seen, in which the parting line is located in the plane of the tape cutting device 52 and the two bands 48 are severed together while with the material lane 41 only have the segments 33 and 34 in contact by the Band sections 14, 16 again free segment 35 from the release station III Moved in the direction of takeover station I and its angular speed relative to that of the segment 36 is adapted so that its part-cylindrical segment surface 38 seamlessly adjoins the segment surface of segment 36 to take over the two Bands 48 connects.

The construction of the described YorrsOctctheng can be done without large technical effort in a / dimension realize that they are in already existing systems for the production of diapers are advantageously interposed can. Here it is already sufficient if the circular path along which the segments are located move, has a diameter of approx. 600 mm.

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Claims (11)

Claims 1. A method for applying an elastic band on predetermined, consecutive sections of a material web, in particular for the manufacture of diapers1 in which the elastic band grips at the front end and is stretched in the direction of its longitudinal extent over a partial length, and in which a section of a predetermined length separated from the stretched part length, in stretched Condition on one flat side of the material moving in one direction brought in, brought into adhesive contact with it, moved on with it and finally it is released that it is not possible to do so the stretched band section (14 or 16) after being separated from the rest of the elastic band (48) with an initial conveying speed for stretching the elastic Belt (48) is moved at a higher conveying speed in the direction of the material web (40) will. 2. The method according to claim 1, characterized in that the from elastic band (48) to be separated section only to the effectively required Stretched length and in this length until it is applied to the material web (40) is held. 3. The method according to claim 1 or 2 for application in sections elastic band sections for the production of pant diapers, characterized in, that in a known manner, two at the same time at a parallel distance next to each other lying stretched tape sections (14, 16) produced, the material web (40) fed and be firmly connected to this. 4. Device for performing the method according to one of the preceding Claims, characterized by a plurality of movable in the same direction and in each case clamping means (clamping elements 40, 42) for fixing at least one stretched Belt section (14 or 16) having conveyor elements (segments 32-36), the one after the other to a take-over station (I) to take over the front end of the elastic Tape (48), then for stretching the same an intermediate position in which a Stretched band section (14 or 16) of a predetermined length set on the conveyor element and is separated from the rest of the elastic band (48), then a transfer station (II) for transferring the stretched strip section (14 or 16) to the material web (40) and finally the transfer station (I) again, the Conveyor elements (segments 32 - 36) between the intermediate position (belt cutting device 52) and the upper station (II) with a higher conveying speed than along the conveyor line between the transfer station (I) and the intermediate position (belt cutting device 52) are movable. 5. Apparatus according to claim 4, characterized in that the conveying speed of the conveyor elements (segments 32 - between the intermediate position (belt cutting device 52) and the transfer station (II) can be changed. 6. Apparatus according to claim 4 or 5, characterized in that the conveyor elements (segments 32 - 36) from the intermediate position (belt cutting device 52) until the release and transfer of the stretched strip section (14 or 16) on the material web (40) movable at increased conveying speed are. 7. Apparatus according to claim 5 or 6, characterized in that the conveyor elements (segments 32-36) can be moved along a circular path the receiving station (I), a tape cutting device, at an angular distance from one another (52) for severing the stretched band section (14 or 16) from the rest of the band (48) and the transfer station (II) are arranged. 8. Apparatus according to claim 7, characterized in that the conveyor elements are formed by segments (32 - 36) pivotable about a common axis (U), and that the clamping means (clamping members 40, 42) on their partially cylindrical segment surface (38) are arranged at the transfer station (I) on the tape cutting device (52), optionally on an adhesive application device (50) and on the top station (II) can be moved past. 9. Apparatus according to claim 8, characterized in that the segments (32-36) can be driven by a drive device (54) which is one for all Segments (32-36) common to and connected to these, rope-like or chain-like Control member (60) which is used to achieve the change in speed of the segments (32 - 36) over a partial area its size a smaller one Having a radial distance from the pivot axis (30) of the segments. 10. Apparatus according to claim 8 or 9, characterized by a total of five segments (32-36), the segment areas in the area of the takeover station (I) (38) connect two segments (32, 36) to one another. 11. Device according to one of the preceding claims 8 to 10, characterized in that the arc length of the segments (32-36) can be changed.