EP2539264B1 - Core for an endless web of a plastic film - Google Patents

Description

The present invention relates to a winding tube according to the preamble of claim 1.

Such cores are used in winders, known and, for example, in EP 2 048 100 are described. A usually freshly produced, endless plastic film is wound onto a winding tube (a plugged onto the winding shaft sleeve) to a winding of predetermined size. Then the web is cut and the finished roll is preferably replaced by a new flying core flying, so that without delay and possible without loss of material, a new roll can be produced.

Such plastic films are produced in an extraordinary variety of compositions and correspondingly with a wide variety of properties, which then also influence the winding behavior and must be considered accordingly in the winding. Likewise, the respective production speed and the number of coils to be produced in a production run are parameters which must be taken into account for a qualitatively sufficient production with at the same time reasonable costs.

Typical processing speeds range from 2 to 1000 m / min, while the finished wound bales may have a diameter of 50 to 2000 mm and a width of 10 to 6000 mm, respectively. The thicknesses can range from a few μm down to the millimeter range. As an example, foils with a thickness of 4 .mu.m to 25 .mu.m can be mentioned. preferably 8 or 15 microns to 25 microns, which are wound at a speed of 100 m / min and a width of about 300 mm to 770 mm on a winding shaft with 4-fold benefit (ie on a winding shaft four cores are plugged and so four reels wrapped parallel next to each other).

The formulation of in particular plastic films made of polyolefins (such as PE polyethylene or PP polypropylene) ranges from the mono-extruded film consisting from a single layer, to the co-extruded film with three, five or more layers, wherein, for example, adhesives of all kinds can be provided in the layers, as many different multilayer films arise.

Today in the field of silage and stretch films about forty to fifty recipes are known, which have the respective desired different properties in the application: in northern countries, for example, it is desirable in agriculture, that wrapped in foil grass bales, up to 500 kg and should remain on the field, even remain snowy in shape, which requires a film with high strength. In other countries, the film should be black. Alternatively, a film of a particular color, e.g. green for optical reasons, are preferred.

If a grass bale is wound, the adhesive contained between the plastic layers of the films ensures that the individual windings adhere to one another around the grass bale, so that the winding has stability. When the bale of grass is formed, when the film is unwound from the wrapping, a typical, scratching sound is produced which, depending on the adhesive, is louder or quieter. Various farms require quietly releasing films, which has a corresponding influence on the overall recipe of the film.

Likewise in the area of, for example, stretch films used for the packaging of goods stacked on pallets, as protective films (for example in electronics) or as food films. Thus, the food film used in the household adheres approximately at the edge of the plate by the adhesive at the place of wrap around the plate edge due to the local pressure generated by it. Again, the recipes are as numerous as the possibilities of using the slides and tailored to the particular use.

Depending on requirements, the production varies between the production of only a few identical wound bales for special applications up to the mass production of the same wound bales.

Due to the different formulations, the films themselves have different properties, which in turn must be taken into account in the winding for faultless film winding, which special requirements on the winder parameters such as web tension, winding pressure, speed film thickness, and elasticity of the film and stickiness of the film fresh wrap etc.

The finished wound film (the winder is usually immediately downstream of the film producing extruder) is still alive, since the various plastic layers still calm and the trapped between the layers of air or introduced substances, often the adhesives, change and also by the Migrate layers. In other words, the process of producing the films after winding is not yet completed.

The finished rolls must therefore be stored directly following the winding controlled, which often happens at a temperature of 30 to 45 ° C for up to four days. The resulting internal changes in the film have a change in the coil itself result: the winding changes mainly in the roll hardness, which is accompanied by a considerable pressure inside the coil. This pressure is then maintained until the roll for the use of the film is unwound again.

Again, the changes in the wounds still living after winding, depending on the recipe and also depending on the winding parameters different (violent) turn out until the coil has died, i. is no longer subject to further changes and therefore, after the storage mentioned above, is ready for sale and can be transported away.

After using the films fall from cardboard or the necessary stability due to (considerable internal pressure in the winding) mostly made of plastic sleeves. A plastic sleeve costs an average of 1 - 2 euros, (which would also be incurred in a consulate consetencies). Then falls on the user of the film additional work to the empty sleeves to collect, store and return. This often results in the empty tubes being sort of disposed of or simply burned on-site, so that the cost of making the sleeves is lost and the environment is polluted in the event of combustion. Accordingly, attempts have been made to produce a caseless winding by the film has been wound on a winding shaft with radially extended segments. After the completion of the winding, the segments have been retracted, so that the living coil could be pulled off and stored axially from the winding shaft. Inevitably, during the storage of the roll, its inside diameter probably has collapsed on account of the internal pressure increasing in the winding, in each case at the points which, during the winding, have been situated over a gap between the extended segments of the winding shaft. This in FIG. 1 break-ins are fatal because the disturbance due to break-in propagates from the inner surface of the roll to its interior and interferes with the proper handling of the foil. Often, film breaks during processing at the location of the disturbance, so that a significant portion of the length of the film is lost for use. If the torn-off end were caught again and continued, a renewed tear would soon follow.

For some less sensitive stretch films that do not contain adhesive, a sturdy wrap can be wound on a comparatively thin sleeve as the wrapper will only change a little until it dies. However, this requires a winding under kgeringem train and low contact pressure, otherwise thin sleeve could be crushed, in which case the sleeve also clamps due to the winding in the stable winding and can not be deducted from this.

Such coils are then inevitably very soft and have large air inclusions between the layers, which is undesirable: at the location of the air pockets wrinkles occur in the wound layers, so that the film loses transparency (the developed film is insufficiently transparent at the location of the folds, so that the packaged goods are no longer visible or writings for the identification of the estate on this can no longer be read) and also their adhesion is disturbed, since in the winding at the location of the wrinkles under different pressure prevailed and thus locally changed the properties of the films.

In other words, it is the case that thinner and thus cheaper sleeves, which also make transport cheaper, have to be bought with a deteriorated quality of the film.

Finally, it is conceivable to change the recipe of the film so that the winding without sleeve is removed from the winding shaft and then remains stable, i. does not break. After today's Kentnis it is however so that then the foil no longer corresponds to the requirements of the market due to the changed formulation, thus qualitatively not enough.

Accordingly, the rolls are still wound on sleeves and brought with these sleeves to the consumer.

Accordingly, it is the object of the present invention to allow the winding of flexible webs of the type mentioned above without the previously necessary circulation of sleeves.

FR 1 145 624 A discloses a winding tube attachable to a winding tube for winding an endless, flexible web to a winding, wherein the winding tube has means to adjust the diameter of its surface to be wound between a reduced diameter idle state and an expanded working state, the winding surface in the expanded state without joints trained and supported against the operating pressure around uniformly dimensionally stable against the inside.

DE 11 37 828 B discloses an attachable to a winding shaft winding tube for the winding of a thread, wherein the winding tube has means to adjust the diameter of its surface to be wound between a reduced diameter idle state and an expanded working state at a constant inner diameter, the winding surface is formed in the expanded state without joints.

This object is achieved by a winding tube according to the characterizing features of claim 1.

The fact that the diameter of the wound surface of the winding tube to be wound can be changed, it is possible to remove the winding with its winding tube of the winding shaft and stored with unchanged in the winding winding tube until the winding has died. Then, the diameter of the winding tube can be reduced and these are withdrawn from the winding, which would not be possible due to the pressure prevailing in the inner pressure without reducing the diameter of the winding tube. Characterized in that the surface to be wound of the winding tube is formed in the expanded working state substantially seamless and against the operating pressure all around substantially uniformly dimensionally stable is supported against the inside, the winding remains during the winding in its inner region without interference, so that it no longer breaks after storage when the sleeve is removed, so he transported accordingly without sleeve to the consumer and in use without interference can be fully processed.

As a result, only sleeves for the production quantity of four days are required in the production of foils or in the winding, since the wraps have died at the latest after four days and the winding cores according to the invention could be used on site for new wraps. Starting from a daily production of 1250 coils per production line (whereby the average manufacturer has about 8 production lines), then 5,000 retractable cores are required, in contrast to the conventional production of about 450,000 annually produced conventional cores (at costs of approx. 1 to 2 € for the production of a sleeve). 8 production lines eliminate production, transport and disposal of over 3 million cases.

It should be added at this point that depending on the recipe, the necessary storage time until dying of the roll can be only short (if it is still a few days for many recipes). But even with short or shortest storage time results in the advantage described above. Likewise, if a roll is to be transported immediately, since it does not depend on a uniform formula in the winding subsequent interval following a specific recipe: a conventional sleeve can not be deducted without disturbing the inner portion of the roll, since the winding already due to the winding tension or Contact pressure of a pressure roller during the winding has an internal pressure.

Preferred embodiments of the inventive winding tube are described in the dependent claims.

Fig. 1

einen Wickel der gemäss dem Stand der Technik gewickelt worden ist und eine Störung im inneren Bereich aufweist,

Fig. 2

eine erfindungsgemässe Wickelhülse mit einer Sekundärhülse,

Fig. 3

eine Ansicht der Segmentschalen der Wickelhülse von Figur 2 vom linken Ende her,

Fig. 4a

eine Ansicht eines fertigen Wickels, gewickelt auf die Wickelhülse von Figur 2, gesehen vom rechten Ende her, wobei sich die Wickelhülse im expandierten Arbeitszustand befindet,

Fig. 4b

eine Ansicht des fertigen Wickels von Figur 4a, gesehen vom linken Ende her, wobei sich die Wickelhülse im durchmesserverkleinerten Ruhezustand befindet,

Fig. 5a

eine Ansicht der Wickelhülse von Figur 2 im expandierten Zustand,

Fig. 5b

eine Ansicht der Wickelhülse von Figur 2 im durchmesserverkleinerten Zustand,

Fig. 6

eine Ansicht eines gestorbenen Wickels, dessen Wickelhülse abgezogen werden kann, und

Fig. 7

eine Ansicht einer weiteren Ausführungsform der erfindungsgemässen Wickelhülse.

Fig. 8a

einen Querschnitt durch eine zusätzliche, bevorzugte Ausführungsform der erfindungsgemässen Sekundärhülse,

Fig. 8b

einen Querschnitt durch eine weitere bevorzugte Ausführungsform der erfindungsgemässen Sekundärhülse

Fig. 9

eine Ansicht der Sekundärhülse von Figur 8, und

Fig. 10

eine Ansicht noch einer weiteren Ausführungsform der erfindungsgemässen Wickelhülse.

The invention is explained below with reference to the figures. It shows:

Fig. 1

a winding which has been wound according to the prior art and has a disturbance in the inner region,

Fig. 2

an inventive winding tube with a secondary sleeve,

Fig. 3

a view of the segmental shells of the winding tube of FIG. 2 from the left end,

Fig. 4a

a view of a finished coil, wound on the winding tube of FIG. 2 seen from the right end, wherein the winding tube is in the expanded working state,

Fig. 4b

a view of the finished roll from FIG. 4a seen from the left end, wherein the winding tube is in the diameter-reduced hibernation,

Fig. 5a

a view of the winding tube of FIG. 2 in the expanded state,

Fig. 5b

a view of the winding tube of FIG. 2 in the diameter-reduced state,

Fig. 6

a view of a dead roll, the winding tube can be removed, and

Fig. 7

a view of a further embodiment of the inventive winding tube.

Fig. 8a

a cross section through an additional preferred embodiment of the inventive secondary sleeve,

Fig. 8b

a cross section through a further preferred embodiment of the inventive secondary sleeve

Fig. 9

a view of the secondary sleeve of FIG. 8 , and

Fig. 10

a view of yet another embodiment of the inventive winding tube.

Fig. 1 shows a stored, that is, dead winding 1, which has been wound on a winding shaft according to the prior art. Such segment shafts are known in the art and generally have three radially extendable from the winding shaft segments, which increase the diameter of the winding shaft during the winding, so that reduced after winding the diameter by retracting the segments and so deducted the winding of the winding shaft can be.

A wound produced in this way shows even after removal from the winding shaft (depending on the recipe of the film) barely recognizable or clearer pressure marks: adjacent segment edges are on the innermost winding layer of the coil, but the rounding of the inner region 2 of the roll 1 in usually not disturbed.

After storage, the picture shown in the figure results: at the location of the previously only slight pressure marks, the winding has collapsed in its inner region 2. Depending on the recipe, a corresponding interference zone 3 extends to different degrees into the winding 1 and later prevents the proper unwinding of the wound material web or film. The figure shows only one of the three interference zones present in the case of three winding wave segments due to the selected image detail. The wound film is indicated by the lines on the end face of the roll 1, as well as the broken windings in the interior of the roll 1 at the location of the fault zone 3. Thus, a survey 4 is visible on the inner region 2, which has approximately a triangular cross-section.

FIG. 2 shows a erfindungsgmässe winding tube 10 in an exploded view. Shown is a secondary sleeve 20 whose length corresponds at least to the windable surface of the winding tube 10, and on which a film can be wound into a winding. The secondary sleeve 20 preferably has a hard surface and consists for example of a metal sheet, such as a steel sheet. But it can also consist of a plastic such as CFRP. It has a running over its length insert 21 having an elastic material, for example, consists of a rubber which is vulcanized at the edges 22, 23 of the secondary sleeve 20 at. The person skilled in the art can easily produce the connection between the rubber and the edges 22, 23 that is optimal in the specific case. As a result, the secondary sleeve 20 provides a seamless surface.

This arrangement allows to widen the secondary sleeve 20, since this is elastically deformable: once it itself is resiliently expandable, then allows the elastic material of the insert 21 necessary in the expansion increase in the length of the circumference. Thus, the secondary sleeve 20 has a diameter-reduced resting state (see below to FIG. 5 b) and here and in FIG. 5 assume a shown expanded working state or be adjusted between these two configurations.

Preferably, the secondary sleeve 20 is designed such that it assumes the rest position unrestrained, while in the expanded state of the then elastically stretched insert 21 occupies substantially the thickness of the secondary sleeve 20. This results in a uniformly round surface of the secondary sleeve 20, which makes it possible to wrap even the most sensitive foils properly, without disturbing the removal of the winding tube 10 from the decayed coil a fault in the sense of the interference zone 3 of FIG. 1 results. Particularly preferably, ie for the winding of sensitive formulations, the material of the insert 21 is constant in volume elastic, so that it provides a similarly solid pad for the film to be wound during the executed under pressing winding, as in the secondary sleeve 20 outside the insert 21 of Case is.

Further, it is preferred that the insert 21 extends helically along the length of the secondary sleeve, as shown in the figure. This supports the gentle winding: the film to be wound passes along a surface line on the resulting winding and is pressed there by the winding tension and usually by a pressure roller to the winding. The tendency to form an interference zone with particularly sensitive formulations is due to the different (compared to sheet softer) material in the insert 21 (at least theoretically) still given because there the film could still come into the winding due to the winding tension or the pressure of the pressure roller , In a helical insert this is not the case, since the pressure roller next to the insert on the hard material of the secondary sleeve 20 runs, so can not come into the winding.

In a further, not shown embodiment, it is possible to form the insert preferably as a flexible band of the thickness of the secondary sleeve 20. Then, the band is stretched in the expanded state and hang in diameter-reduced condition loosely between the edges 21, 23. In yet another embodiment, two (or more) inserts can be provided in the secondary sleeve, with the result that then the secondary sleeve is not in the type of a slotted sleeve can expand, but their separated by the inserts sections radially away from each other (and against each other) can be moved.

The skilled person can produce by combining the preferred features shown above, a secondary sleeve for the winding of all possible, so even the most demanding films, or choose a simpler secondary sleeve, for example with a non-constant volume material in the insert 21 or a straight insert 21, with the Less demanding films can still be wound properly, so that the dead coil still no interference occurs in the inner region.

In other words, the secondary sleeve 20 according to the invention represents a means for interposing the surface of a winding tube 10 to be wound to reduce a diameter-reduced resting state and an expanded working state, wherein the winding surface formed in the expanded state without joints and is supported against the operating pressure substantially uniformly dimensionally stable against the inside, which disturbances can no longer form.

FIG. 2 further shows three segment shells 30, 31, 32, which are enclosed by the secondary sleeve 21 and protrude from this due to the explosive representation of the figure. The segment shells 30 to 32 in turn rest on a conical mandrel 50 formed cone, which can be moved according to the arrow shown in the figure from the left side between the segmental shells 30 to 32. The mandrel 50 has a centrally axially extending bore 52, which allows aufzustecken him on a winding shaft of a winder. the bore 52 forms the inner surface of the winding sleeve according to the invention, so that, as a result, the diameter of its surface to be wound can be adjusted as described herein between a diameter-reduced resting state and an expanded working state while the inner diameter remains the same. The segment shells 30 to 32 themselves are conically shaped, Thus they increase in thickness along their length from the left end to the right end. Generally speaking, the segment shells 30 to 32 are at the end of lesser thickness at which the conical mandrel 50 is inserted. The outer surfaces 33 to 35 of the segmental shells 30 to 32 lie on a common cylinder jacket, the pitch of the inner surfaces 36 to 38 corresponds to the pitch of the outer surface 51 of the mandrel 50, whereby the segment shells 30 to 32 are formed opposite to the mandrel 50.

Shown are also the end faces 42 to 44 at the thicker end of the segmental shells 30 to 32, while in FIG. 3 at the thinner end of the end faces 45 to 47 can be seen.

The length of the segmental shells 30 to 32 should correspond at least to the length of the windable surface of the winding tube 10, so that the secondary sleeve 20 is properly supported over this length. The length of the spine 50 is preferably (but not necessarily in view of the thickness of the segmental shells 30 to 32) also the length of the windable surface of the winding tube 10 in order to properly stabilize the segmental shells 30 to 32 in operation.

In the exploded view of the FIG. 2 corresponds to the position of the segmental shells 30 to 32 and thus the position of the secondary sleeve 20 to the expanded working state of the winding tube 20: the segment shells are separated from each other by a respective gap 39 to 41, with the result that they can fall against the inside when the mandrel 40 is pulled out of the winding tube 10, until the gaps 39 to 41 close and the segment shells 30 to 32 abut each other. Then, the secondary sleeve 20 also closes due to its elastic material, or by the elastic insert 21 contracts, and comes with a reduced diameter in its resting state (as in FIG. 5 b is shown). The skilled person will form the gap of predetermined width for the specific case, such that the ratio of gap width to diameter reduction with respect to the thickness of the winding tube or the use of a hose 71 optimally satisfies.

The mandrel 50 is provided in the embodiment shown in the figure with guide cam 53 which run during retraction of the mandrel 50 in the segmental shells 30 to 32 in the columns 39 to 41 and so the segmental shells 30 to 32 during the adjustment of the diameter of the winding tube 10th keep in correct mutual position.

This results in a wedge assembly consisting of the cone and the segmental shells 30 to 32 such that by fully inserting the mandrel 40 in its operating position, the winding tube 10 is brought over the cooperating wedge surfaces in their expanded working state, while by pulling out of the mandrel 40th the position of the segmental shells 30 to 32 and thus also the secondary sleeve 20 is adjusted until the winding tube 10 reaches the diameter-reduced state.

In the figure it is shown that the helically extending over the length of the secondary sleeve 20 insert 21 rests completely on the segment shell 32, with the advantage that it is supported by this over its entire length. Accordingly, the helix reaches less than one-third of a full turn, since the segment shell also occupies less than one third of the available circumference, given the gaps 39-41.

If only two segment shells are used, the helix is correspondingly less than half a turn; if there are more than three segments, for example four, less than a quarter of a turn, and so on.

FIG. 3 shows the segmental shells 30 to 32 in a view with respect to the end faces 45 to 47 of the thinner end, ie from the insertion side of the mandrel 50 ago. The position of the segment shells 30 to 32 corresponds to that of FIG. 2 , In the embodiment shown, two of three locking cams 48, 49, which are provided on each of the segmental shells 30 to 32 and which are formed inwardly, are further illustrated in a latching groove 53 (FIG. FIG. 2 ) of the mandrel 50 so that the operative end position of the retracted mandrel 50 is defined. Not shown in the figure is the associated mandrel with its bore, which forms the inner diameter of the sleeve.

FIG. 4a shows a finished, still living coil 60, as it is stored until the changes still running in the winding are completed so far that the winding tube 10 can be removed from the winding without the winding 60 then still forms interference. Shown is a view of the right side of the winding tube 10 according to the Figures 2 and 3 ,

FIG. 4b shows the winding 60, the winding tube 10 has been reduced in diameter after the extension of the mandrel 60, not shown for relieving the figure, so that the winding tube can be removed from the winding 60.

The figure shows the segmental shells 30 to 32 in a view with respect to the end faces 42 to 44 of the thicker end ago. The segment shells 30 to 32 have fallen inwards and stand on each other at their lateral edges. Accordingly, the secondary sleeve 20 has narrowed and the insert 21 contracted. There is now a gap 61 between the winding 60 and the secondary sleeve 20, which allows easy removal of the winding tube 10, which is then used for a next winding. The winding 60 can be easily stored until removed and handled for use completely and without loss of material.

The FIGS. 5a and 5b show the composite winding tube 10 in the expanded state and in the idle state, wherein the winding is omitted for better illustration. Likewise shows FIG. 6 a perspective view of the roll 60 as shown in FIG FIG. 4b ,

FIG. 7 shows a further embodiment of a winding tube 70 according to the present invention. Instead of a secondary sleeve 20 ( FIGS. 2 to 6 ) is a stretch-elastic hose 71 is provided, which rests on the segmental shells 30 to 32 and the columns covered 39 to 41 and forms with its outer side 72, the windable surface of the winding tube 70. Thus, the winding tube 70 can be widened from the diameter-reduced resting state to the expanded working state. The windable surface of the winding tube 70 is seamless, but not supported on the columns 39 to 41 and kept in shape only by the tension in the stretched tube 71. The skilled person will therefore only less sensitive, but a variety of formulations wrap with such a winding tube 70, as can be achieved with the corresponding formulations of the inventive advantage also with this embodiment. Preferably, a 2 to 8 mm thick hose made of polyurethane is used, so that there is a sufficiently stretchable, but over the gap but stiff hose 71 with abrasion resistant surface, the polyurethane has the advantage that the hose surface in eventual Injuries close and not open, which is desirable in terms of disturbances in the winding 70.

Here, the expert can also provide an additional, between the tube 71 and the segmental shells 30 to 32 arranged slotted over its length sleeve whose length corresponds at least to the windable surface, wherein the slot is preferably helical and the change in the circumference of the secondary sleeve between allowed the dormant state and the expanded working state and wherein the tube then encloses the sleeve, is expanded in the expanded state by this and rests auf.Angesichts the variety of recipes, a general rule can not be specified when a winding tube 10 used with a secondary sleeve 20 must be, and when a winding tube 70 with a rubber hose 71 still enough. This also applies to the thickness of the rubber hose 71 required for a winding sleeve 70 in order to avoid disturbances. Here, the person skilled in the art depends on tests. On the one hand, he will know from his production know-how particularly sensitive formulations and in these preferably use a winding tube 10 with secondary sleeve 20. On the other hand, he can determine for less sensitive or new, yet unknown recipes with a few experimental windings, whether a winding tube 70 is compatible with an elastic tube 71 or not. Optionally, the optimum thickness of the tube 71 can be further determined. Such attempts are worthwhile in the case of large production quantities (since the then possibly usable winding sleeves 70 are cheaper with only one hose), while in the case of small batches advantageously winding sleeves 10 with secondary sleeves 20 can be used in any case.

For the most sensitive formulations it may be advantageous to additionally provide a winding tube 10 with secondary sleeve 20 with an elastic tube, in which case the tube encloses the secondary sleeve 20 and compensates for the finest unevennesses in the region of the insert 21. In addition, the use of such a hose may allow the secondary sleeve 20 to be manufactured inexpensively, ie with some unevenness in the region of the insert. Again, the skilled person can, if necessary, depending on the recipe and the associated tolerance of the coil against a not completely uniform to be wound surface to determine the optimum for the specific application form of a winding sleeve according to the invention.

Fig. 8a shows a cross section through an additional preferred embodiment of the inventive winding tube, wherein the secondary sleeve 80 with respect to the above, for example, with reference to Figures 2 . 5a and 5b described secondary sleeve 20 is modified. This secondary sleeve 80 can thus be used in FIG. 2 Replace shown secondary sleeve 20 and, for example, together with the wedge assembly shown there, (consisting of the cone 50 and the segmental shells 30 to 32) are used.

Accordingly, the shows FIG. 8a only the modified secondary sleeve 80, but not the associated wedge assembly with the cone 50 and the segment shells 30 to 32.

The secondary sleeve 80 consists of a tubular body 81 of elastically stretchable material, preferably of a plastic such as polyurethane or a rubber, the skilled person can easily determine the material to be used in the specific case himself. The outer surface 82 of the main body 81 (which here is at the same time the outer surface of the secondary sleeve 80 itself) forms the surface to be wound of the winding tube, the component of which is the secondary sleeve 80.

On the inside of the main body 81, and thus on the inside of the secondary sleeve 80, at least two, preferably three or more formed here as shells 83 to 85 supporting elements are formed which lie in the expanded state shown in the figure at a predetermined distance from each other, which is dimensioned by the person skilled in the art that the diameter of the secondary sleeve at rest is small enough to safely pull the sleeve from the winding. These trained as shells 83 to 85 support elements extend the length of the secondary sleeve 80 to at least over the length of the surface to be wound. Thus, the inner surfaces 86 to 88 of the shells 83 to 85 form portions of the inner surface of the secondary sleeve 80.

This configuration allows a secondary sleeve 80 to be mounted on the retracted segment shells 30-32 of a wedge assembly (see FIG. FIG. 2 ), in which case when retracting the mandrel 50 (FIG. FIG. 2 ), the base body 81 and thus the secondary sleeve 80 is elastically stretched in the circumference, so that increases their diameter. In this case, the secondary sleeve is attached to the wedge arrangement in such a way that the support shells 83 to 85 pass over the gaps 39 to 41 formed by the segment shells 30 to 32 (FIG. FIG. 2 ) and cover them with it. Each of the support shells 83 to 85 is thus associated with a gap 39 to 41. Conversely, the webs 89 to 91 of the main body 81 then rest on the segmental shells 30 to 32. It follows that then virtually the entire outer surface 82 of the secondary sleeve 80 is securely supported, once on the hard support shells 83 to 85, and then on the webs 89 to 91. Thus, the gaps 39 to 41 are securely bridged and a perfect winding produced. Negligible for the winding result are the small gaps 91,91 'to 93,93', which form in the expansion of the elastic body 81 against the not or hardly expanding support shells 83 to 85 in the scope.

According to the invention, the support shells 83 to 85 have a material harder than that of the expansible base body 81 (the extensibility of which allows the circumferential length to be changed between the rest state and the working state), so that it functions as above the gaps 39 to 41 (FIG. FIG. 2 ) lying support plates can meet. Preferably, the support shells 83 to 85 made of a sheet or a glass fiber reinforced plastic. It should also be noted here that a simple rule for the hardness of the support shells 83 to 85 can not be given, since this depends on the recipe of the film to be wrapped: the more sensitive the recipe, the harder or more rigid the support shells must be.

FIG. 8b shows an embodiment of a secondary sleeve 80 'in which the support shells 83 to 85 completely embedded in the expandable body 81' and are enclosed by this. However, always the support shells are 83 to 85 in the expanded state of the winding tube side by side at a distance to each other and are arranged opposite the radially extendable segment shells such that each space between the radially extendable segment shells is covered by an associated support shell 83 to 85.

• Weisen die Stützschalen einen mittleren Bereich auf, der zwischen den Längskanten der Stützschalen iegt und die grösste Dicke aufweist, während sich die Stützschalen gegen die Längskanten hin verjüngen, bewirkt dies einen besonders sanften und gleichförmigen Übergang zwischen den Zonen ohne Stützschalen des Grundkörpers und den Zonen, in denen Stützschalen vorhanden sind, mit der Folge, dass die Wicklung besonders gleichförmig erfolgt.

This arrangement has the advantage that the lying inside the body support shells 83 to 85 are firmly anchored in this and therefore particularly suitable for a further preferred embodiment of a support shell:

• If the support shells have a central region which is between the longitudinal edges of the support shells and has the greatest thickness, while the support shells taper towards the longitudinal edges, this results in a particularly smooth and uniform transition between the zones without support shells of the main body and the zones, in which support shells are present, with the result that the winding is particularly uniform.

FIG. 9 shows a view of the secondary sleeve 80 of FIG. 8 , Shown is that the support shells helically along the inside of the secondary sleeve 80 along. This helix serves the same purpose as the helix of the insert 21 of a secondary sleeve 20: a pressure roller of a winder can then not sink into the somewhat softer material at the location of the webs 89 to 91. Accordingly, depending on the number of supporting shells used, the helix has the same dimensions as set forth with reference to the insert 21.

FIG. 10 shows a cross section through a further embodiment of a winding sleeve 100 according to the invention, with a primary sleeve 101 of, for example, metal (or a plastic such as CFRP), which are clamped on a winding shaft of a conventional winder in the usual way can. On the primary sleeve, designed as a hollow cylinder, pneumatic element 102 is provided, which extends along the windable surface of the winding tube along and preferably forms with its outer surface 103, the windable surface. Ridges 104 connected to the primary sleeve 101 keep the outer surface substantially cylindrical despite the chambers 105 formed by the ribs 104. The ribs 104 have openings 105 through which a fluid introduced via a feed line 106 can flow into all the chambers 108 under pressure equalization. Under operating pressure, the pneumatic element widens and forms a seamless expanded surface to be wound. If the pressure is released, the surface 103 of the pneumatic element 102 is incident, so that the winding tube 100 can be removed from the decayed coil.

Preferably, the pneumatic element consists of a hose made of polyurethane, which is vulcanized at the edge of the primary sleeve 101 or is held by Briden. In this case, it may be advantageous to insert airtight, possibly expandable, annular bags in the chambers 105, so that the edge-side attachment of the hose must meet only the mechanical requirements.

In another embodiment, the outer surface 103 of the pneumatic element 102 is enclosed with a hose of a non-stretchable fabric such as a polyester or glass fiber fabric, which is stretched in the expanded state of the winding shaft 100 and prevents due to its shape that the elastic material of the pneumatic element due to the internal pressure in the middle of the winding tube 100 bulges. Such fabrics usually have an uneven surface because of the strong fabric fibers. Accordingly, then a thin rubber tube made of PUR can be pulled over the fabric tube, which compensates for the unevenness caused by the fibers and provides a perfectly smooth surface to be wrapped.

Claims (19)

1. A winding sleeve that can be placed onto a winding shaft for the purpose of winding a continuous flexible plastic web to form a wound roll (10, 60, 70), characterised in that, the winding sleeve has means to adjust the diameter of its surface on which winding takes place between a non-operational state with a reduced diameter, and an expanded operational state, while its inner diameter remains constant, wherein the surface on which winding takes place in the expanded state is designed seamlessly, and is supported around its periphery against the internal operating pressure in an essentially uniform and dimensionally stable manner.
2. The winding sleeve in accordance with Claim 1, wherein the means have a secondary sleeve (80) that can be elastically expanded over its periphery, the outer surface (81) of which forms the surface of the winding sleeve on which winding takes place, and wherein support elements are formed on its inner face, running longitudinally on the latter over at least the length of the surface on which winding takes place; in the expanded operational state these are located at predetermined separation distances from one another.
3. The winding sleeve in accordance with Claim 2, wherein the supporting elements are designed as shells (83 to 85), the inner surfaces of which form sections of the inner surface of the secondary sleeve (80), and wherein the shells (83 to 85) preferably run helically along the inner face of the secondary sleeve (80).
4. The winding sleeve in accordance with Claim 2 or 3, wherein the secondary sleeve (80) consists of an elastically expandable material, preferably a plastic such as polyurethane or rubber, whose ability to expand allows the alteration of the peripheral length between the non-operational state and the operational state.
5. The winding sleeve in accordance with Claim 4, wherein the supporting elements (83 to 85) have a material that is harder than the expandable material of the secondary sleeve (80), and preferably consist of sheet metal or a glass fibre-reinforced plastic.
6. The winding sleeve in accordance with Claim 1, wherein the means have a secondary sleeve (20) the diameter of which can be elastically expanded, the length of which corresponds at least to that of the surface on which winding takes place, and which over its length has at least one insert (21), which allows the alteration of the length of the periphery of the secondary sleeve (20) between the non-operational state and the expanded operational state, and in the expanded state has essentially the thickness of the secondary sleeve (20) .
7. The winding sleeve in accordance with Claim 6, wherein the insert (21) runs helically over the length of the secondary sleeve (20), and the helical line in the region of the surface on which winding can take place achieves less than a half, preferably less a third, particularly preferably less than a quarter, of a full revolution.
8. The winding sleeve in accordance with Claim 6 or 7, wherein the material of the insert is elastic and can preferably be elastically deformed at a constant volume.
9. The winding sleeve in accordance with one of the Claims 6 to 8, wherein the secondary sleeve (20) has a hard surface and preferably consists of a sheet metal, particularly preferably a steel sheet.
10. The winding sleeve in accordance with Claim 1, wherein the means have a wedge arrangement with a cone (50) and at least two, preferably at least three, segment shells (30 to 32), designed in an inverted manner relative to the cone (50); the shells are designed such that the outer surfaces of the segment shells (30 to 32), which are located on the cone (50) in an operationally-ready state, are located on a common cylindrical liner, and which in each case include a gap (39 to 41) of a predetermined width, wherein the length of the segment shells (30 to 32) and preferably that of the cone (50) corresponds at least to the length of the surface of the winding sleeve on which winding can take place, and the cone (50) has a central axially running bore (52), which enables it to be placed onto a winding shaft.
11. The winding sleeve in accordance with Claims 2 and 10, or Claims 6 and 10, wherein the secondary sleeve (20) is positioned on the segment shells (30 to 32) such that the supporting elements in each case cover an associated gap (39 to 41), or the at least one insert (21) rests completely on one of the segment shells (30 to 32).
12. The winding sleeve in accordance with Claim 1, wherein the means are provided as a pneumatic element, designed as a hollow cylinder, and arranged concentrically with the longitudinal axis of the winding sleeve (100); the pneumatic element extends along the surface of the winding sleeve on which winding can take place, preferably forms with its outer surface (103) the surface on which winding can take place, and under operating pressure expands the winding sleeve into the expanded operational state, wherein in a depressurised state of the pneumatic element the winding sleeve assumes the non-operational state with a reduced diameter.
13. The winding sleeve in accordance with Claim 12, wherein the pneumatic element has inner, peripheral ribs (104), which limit its maximum outer diameter in a predetermined manner, and wherein a tube of a flexible, non-expandable fabric is provided on the outer face of the pneumatic element, which in the expanded state of the pneumatic element closely surrounds the latter and maintains it in a cylindrical shape.
14. The winding sleeve in accordance with Claim 1, wherein the means have a tube (71) consisting of an elastic material, preferably polyurethane, the outer surface (72) of which forms the surface of the winding sleeve on which winding can take place, wherein the elastic material is expandable such that the tube (72) can be widened from its non-operational state of reduced diameter up to an expanded operational state.
15. The winding sleeve in accordance with Claims 10 and 14, wherein the tube (71) encloses the segment shells (30 to 32) and in the expanded operational state, widened by means of the latter, is located on the latter.
16. The winding sleeve in accordance with Claim 14, wherein the means have a secondary sleeve (20) that can be widened in diameter and is slit over its length, the length of the secondary sleeve corresponds at least to that of the surface on which winding can take place, wherein the slit is preferably of helical design, and allows the alteration of the periphery of the secondary sleeve (20) between the non-operational state and the expanded operational state, and wherein the tube encloses the secondary sleeve (20), in the expanded operational state is widened by means of the latter, and is located on the latter.
17. The winding sleeve in accordance with Claims 2, 6 and 10, wherein the tube encloses the secondary sleeve (20), which in turn is located on the segment shells (30 to 32).
18. The winding sleeve in accordance with Claim 2, wherein the supporting elements are designed as supporting shells, which run in the interior of the winding shaft sleeve on a common diameter between the surface on which winding takes place and its inner surface, and in the expanded state of the winding shaft are located side-by-side with a separation distance from one another, and wherein the supporting shells are arranged relative to the radially outwardly traversable segments such that each intermediate space between the radially outwardly traversable segments is covered by an associated supporting shell.
19. The winding sleeve in accordance with Claim 18, wherein the supporting shells taper from a central region between the longitudinal edges relative to the latter.

Images