TREATMENT MACHINE FOR A FLEXIBLE MATERIAL WEB, IN PARTICULAR PLASTIC FILM, WHICH CAN BE PASSED THROUGH A TREATMENT FURNACE

Abstract

A treatment machine comprises at least two successive zones in an extraction direction of the material web between which a neutral zone is provided. In the neutral zone, a nozzle arrangement is provided adjacent to a zone exit wall and/or to a leading neutral zone wall on the one hand, and/or adjacent to the chamber inlet wall and/or a trailing neutral zone wall on the other hand, via which nozzle arrangement a gaseous fluid flow reaching a material web is generated. The nozzle arrangement is designed as follows: the respective gaseous fluid flow is directed at a blowing angle in the direction of the adjacent zone exit wall and/or the leading neutral zone wall or the zone inlet wall and/or the trailing neutral zone wall; and the gaseous fluid flow flows as far as the material web, following the zone exit wall, the leading neutral zone wall or the zone inlet wall and/or the trailing neutral zone wall.

Claims

1. Treatment machine for flexible material webs, in particular in the form of a plastic film which can be passed through treatment furnaces, said treatment machine having the following features: the treatment machine comprises at least two successive zones in an extraction direction of the material web, at least one neutral zone is provided between at least two successive zones in the extraction direction, the zone upstream from the neutral zone comprises a zone outlet wall provided with an outlet slot and/or a neutral zone wall, through which the material web exits in the extraction direction from the upstream zone into the neutral zone, the zone subsequent to the neutral zone in the extraction direction, comprises a zone inlet wall and/or a neutral zone wall, which is provided with an inlet slot through which the material web enters the trailing zone in the extraction direction, in the neutral zone, a nozzle arrangement is provided, adjacent to a zone exit wall and/or a leading neutral zone wall on the one hand, and/or adjacent to the chamber inlet wall and/or a trailing neutral zone wall on the other hand, via which nozzle arrangement is provided, via which a gaseous fluid flow reaching a material web is generated, characterised by the following further features: the nozzle arrangement of the nozzle arrangement leading in the neutral zone and/or the nozzle arrangement trailing in the neutral zone is designed in such a way that the respective gaseous fluid flow is directed at an angle of less than 45 in the direction of the adjacent zone exit wall and/or the leading neutral zone wall or the zone inlet wall and/or the trailing neutral zone wall, and that the nozzle arrangement is formed such that the gaseous fluid flow flows following the zone exit wall or the leading neutral zone wall or the zone inlet wall and/or the trailing neutral zone wall as far as the material web.

2. Treatment machine according to claim 1, wherein the nozzle arrangement is designed and/or arranged and/or aligned in such a way that the respective gaseous fluid flow is introduced and/or placed or applied to the zone outlet wall or to the leading neutral zone wall or the zone inlet wall and/or to the trailing neutral zone wall, such that the course of the zone outlet wall or the leading neutral zone wall or the zone inlet wall and/or the trailing neutral zone wall is used as a leading or guide wall for the gaseous fluid flow, in order to further guide and stabilise the gaseous fluid flow in the direction of the moving material web.

3. Treatment machine according to claim 1 wherein the nozzle arrangements comprise nozzle outlet openings, , which are designed or aligned in such a way that the gaseous fluid flow emerging therefrom is directed at a blowing angle against the adjacent zone outlet wall or zone inlet wall, which is less than 40 or less than 35, 30, 25, 20, 15, 12, 5, 10, 8, 7, 6, 5, 4, 3 or less than 2 or 1 and preferably 0.

4. Treatment machine according to claim 1, wherein the treatment machine is designed in such a way that the gaseous fluid flow supplied in the extraction direction through the nozzle arrangement arranged to be leading, is heated to a temperature range corresponding to the treatment temperature in the leading zone or deviating from this temperature by less than 10 C. and/or that the gaseous fluid flow fed in the extraction direction through the nozzle arrangement arranged to be trailing is heated to a temperature which corresponds to the treatment temperature in the following zone or deviates from that temperature by less than 10 C.

5. Treatment machine according to claim 1, wherein the treatment machine is designed in such a way that the gaseous fluid flow exiting into the neutral zone is heated to a temperature which is less than 20 C., in particular less than 15 C., 12.5 C., 10 C., 8 C., 7 C., 6 C., 5 C., 4 C., 3 C., 2 C. and in particular deviates less than 1 C. from the respective treatment temperature which is provided in the zone arranged upstream of the extraction direction with respect to the neutral zone or the zone located subsequent thereto.

6. Treatment machine according to claim 1, wherein the nozzle arrangements comprise nozzle openings consisting of a hole nozzle arrangement and/or a slotted nozzle arrangement.

7. Treatment machine according to claim 1, wherein in the neutral zone, the nozzle device arranged to be leading with respect to the extraction direction of the material web and/or the trailing nozzle device, a common exhaust device is provided for the gaseous fluid stream exiting via the respective nozzle arrangement, which is preferably arranged between the two nozzle assemblies in a position remote from the material web.

8. Treatment machine according to claim 1, wherein each of the two nozzle arrangements is associated with a separate exhaust device, which is preferably arranged adjacent to this or is arranged more remotely relative to the plane of the material web.

9. Treatment machine according to claim 1, wherein the neutral zone is associated with a housing device, preferably in the form of a separate housing device.

10. Treatment machine according to claim 9, wherein in a neutral zone, the nozzle devices and/or the extraction device provided therein are arranged within this separate housing device.

11. Treatment machine according to claim 1, wherein the zone inlet wall, the zone outlet wall and/or the neutral zone walls are aligned at an angle of 90 to the plane of the material web or deviate by less than 20, in particular less than 15, 12, 10, 8, 7, 6, 5, 4, 3, 2 and in particular less than 1 therefrom.

12. Treatment machine according to claim 1, wherein the nozzle arrangement and/or the nozzle outlet opening and/or the zone walls serving as air-guiding devices and/or neutral zone walls are designed and/or arranged such that a fan-shaped and/or planar fluid flow is generated.

13. Treatment machine according to claim 1, wherein the nozzle arrangement and/or the nozzle outlet opening is designed such that it extends over the entire width of the material web or deviates by less than +/20% and in particular by less than +/10% therefrom.

14. Treatment machine according to claim 1, wherein the nozzle arrangement and/or the nozzle inlet opening is designed such that a planar and/or fan-shaped gaseous fluid flow is generated which, at least at the level of the inlet and/or the outlet gap, extends or is spread over the width of the inlet and/or outlet slot.

Description

[0040] The invention will be explained in more detail hereinafter with reference to drawings. In detail:

[0041] FIG. 1: is a schematic side view of a furnace arrangement for a plastic film stretching machine;

[0042] FIG. 2: is a schematic simplified cross-sectional representation perpendicular to the moving material web to clarify the air shutter principle;

[0043] FIG. 3: is an enlarged detail view of a first exemplary embodiment of the invention;

[0044] FIG. 4: is a further representation of a solution principle according to the invention for a modified exemplary embodiment;

[0045] FIG. 5: is a disc-shaped sectional illustration to clarify the use of slotted nozzles;

[0046] FIG. 6: is a representation corresponding to FIG. 5 using hole nozzles; and

[0047] FIG. 7: shows a different exemplary embodiment of a nozzle arrangement using a slotted nozzle and a hole nozzle.

[0048] In FIG. 1, a schematic longitudinal sectional view of a machine 3 is shown, in particular a film stretching machine 3, with a stretching furnace 3, wherein a material web 1, i.e., for example, a plastic film 1, is passed through the film stretching machine 3 and thus through the stretching furnace 3 in the extraction direction A. The machine 3, in particular in the form of a film stretching machine 3, may be a simultaneous stretching unit or a sequential stretching unit, in which longitudinal and transverse stretching is not performed simultaneously (as in the simultaneous stretching machine), but first only in the longitudinal and then in the transverse direction or vice-versa. In principle, it can also be a transverse stretching machine.

[0049] A corresponding machine includes, for example, a corresponding housing structure 5 with a plurality of successive zones 7. In the case of a plastic film stretching machine, the zones 7 are usually treatment zones 7, which are separated from each other by a neutral zone 7n. In this case, the individual treatment zones may comprise not just one but, for example, two or generally several treatment chambers 7. In this case, all treatment zones 7 form the stretching furnace 3, which is traversed by the moving material web 1, in particular in the form of the plastic film 1.

[0050] The structure is usually symmetrical to the plane E, on which the moving material web 1 is moved through the machine. But asymmetrical structures are also possible.

[0051] The individual treatment zones 7 in each case have an inlet gap 9a on the zone inlet side and an outlet gap 9b on the outlet side, which gaps are dimensioned highly and widely enough that the material web 1 can be moved through this slot arrangement without touching the boundary edges of the inlet and/or outlet gap or slot 9a, 9b in order to avoid damage to the material web, in particular in the form of the plastic film.

[0052] As shown schematically with reference to FIG. 1, the plastic film, which in particular is moved through the machine, can be heated to different temperatures in the individual zones. So-called neutral zones 7n may also be provided between the individual zones in order to separate two consecutive zones more strongly, so that no gaseous treatment fluid can easily pass from one zone 7 into a subsequent further zone 7. In order to prevent possible drag effects of the entrainment of gaseous treatment fluid from one zone into a subsequent zonecaused by the moving material webvarious measures are provided according to the invention.

[0053] A neutral zone 7n, which is arranged between zones 7 extending in the extraction direction A, is shown in detail on the basis of the schematic cross-sectional illustration according to FIG. 2.

[0054] On each input and output side, the individual treatment zones 7 comprise zone walls 11, i.e. usually a zone inlet wall 11a and a zone outlet wall 11b, which may hereinafter be named a shutter wall, a shutter boundary wall, or a shutter plate.

[0055] The aforementioned inlet and outlet gaps 9a, 9b are provided in these zone walls 11, in which contextrelative to the neutral zone 7n shown in FIG. 2the leading slot or gap in the running direction A of the film is referred to as the outlet gap, and the gap 9b provided in the extraction direction after the neutral zone 7n in the subsequent inlet zone wall 11a is referred to as inlet gap 9a.

[0056] The columns each have boundary edges extending substantially parallel to the plane E of the moving material web 1, namely boundary edges 13 which run generally parallel to the plane E. These boundary edges should, as far as possible, converge with the film plane E in order to keep the height H of the slot arrangement as small as possible. The smaller the slot height H, the less gaseous fluid can enter from a treatment zone or into a next treatment zone. The corresponding zone walls 11 or so-called shutters or shutter plates 113 are therefore preferably variously adjustable, in such a way that their boundary edges 113 can be adjusted to an optimal distance with respect to the plane E of the moving material web. It must be taken into account that under no operating conditions does the material web 1 touch, for example, the boundary edges 13 of the zone walls 11 or the boundary edges 113 of the actual adjustable shutter or shutter plate usually protruding over the boundary edges 13 in the direction of material web 1, as a result of which a slot or a relevant gap is formed through which the material web 1 is moved. And it must be avoided that this leads to a contact, which can lead to film damage or film breaks.

[0057] In the exemplary embodiment shown, the zone walls 11 in the form of the shutter boundary walls or shutter plates are oriented perpendicular or substantially perpendicular to the plane E of the moving material web and run perpendicular to the material web 1, i.e. perpendicular to the plane E of the plastic film 1 and thus also perpendicular to the reference direction A of the material web 1.

[0058] In the exemplary embodiment shown, a nozzle arrangement 15 is in each case arranged adjacent to a shutter plate 11, specifically outside the actual treatment zones 7. In the case of the neutral zone 7n, therefore, the two nozzle arrangements 15 are provided in the neutral zone 7n.

[0059] The nozzle arrangements 15 comprise a nozzle device 17 with a nozzle outlet opening 19, whereby a gaseous fluid jet S is generated, which is aligned at an angle a to the adjacent zone wall 11, i.e. to the adjacent shutter boundary wall or the shutter plate.

[0060] As a result, a gaseous fluid flow S is generated, as shown by the arrows 25 in FIG. 2.

[0061] The blowing angle should be comparatively small, usually set below 45. Preferred values are below 40, 35, 30, 25, 20 and in particular below 15 or even below 12.5, 10, 8, 7, 6, 5, 4, 3, 2, or less than 1, wherein the angle is usually greater than or equal to 0.

[0062] Due to the Coanda effect, this has the consequence that the gaseous fluid stream S, after striking the surface 11c of a shutter boundary wall, then flows along this shutter boundary wall in the direction of the material web 1 and essentially does not release from this surface due to the Coanda effect.

[0063] If, in this case, the surface 11c and/or the shutter boundary wall 11 in general are aligned perpendicular to the film plane E, the fluid flow S also strikes the material web 1 more or less perpendicularly, as shown schematically in FIG. 2. According to the orientation of the surface 11c of the shutter wall 11 or the shutter wall 11 itself, therefore, the angle of incidence of the fluid flow S with respect to the plane E of the material web 1 is more or less fixed.

[0064] The fluid jet S thereby moves as far as the lower boundary edge 13 of a shutter plate 11 and beyond the lower boundary edge 13 in the direction of the material web 1 until the fluid jet S more or less directly strikes the film plane E.

[0065] The nozzle arrangements 15 and/or the nozzle devices 17 and/or the nozzle outlet openings 19 are thus designed and/or arranged and/or aligned such that the respective gaseous fluid flow S is thus introduced and/or placed or applied to the zone outlet wall lib or to the leading neutral zone wall 113b (FIGS. 3 and 4) or the zone inlet wall 11a and/or to the trailing neutral zone wall 113a (FIGS. 3 and 4) such that the gaseous fluid stream S, after hitting the respective wall of the zone exit wall 11b or the leading neutral zone wall 113b and the zone inlet wall 11a and/or the trailing neutral zone wall 113a, then flows as far as the material web 1. This applies to all exemplary embodiments of the invention.

[0066] In other words, therefore, a planar air jet is generated, which is placed on the corresponding walls, for example, the partitioning wall (shutter plate), so that the course of these walls or partitioning walls then continues to serve as a leading or guide plate in order to continue to guide and stabilise the gaseous media jet directed toward said walls in the direction of the moving material web. In this case, the air jet runs more or less in the area adjacent to the material web in a direction parallel to the partitioning wall (shutter plate), and, specifically, more or less perpendicular to the plane of the moving material web, so as to block the inlet and/or gap.

[0067] As a result of this gaseous fluid flow, the part of the respective inlet and outlet slots 9a, 9b running basically above the film web, but also the remaining region of the inlet or outlet gap 9a, 9b extending below the film web, is closed, since the corresponding nozzle arrangement 15 is provided with the aforementioned nozzle device 17, preferably above and below the plane E of the moving material web.

[0068] In order to improve the effect of blocking the respective gap opening, the gaseous fluid stream S is heated in each case to a temperature range which corresponds to the temperature in the respectively adjacent treatment zone 7.

[0069] If, for example, the circulating air is heated to a temperature range T.sub.1 in the treatment zone 7 upstream of the neutral zone 7n in the extraction direction, the gaseous fluid flow S is preferably also heated to this temperature range T.sub.1 for closing the outlet gap 9b.

[0070] If, for example, a plastic film is heated in a treatment zone 7 subsequent to the neutral zones 7n shown in FIG. 2 to a temperature zone 12 deviating from the temperature range T.sub.1, then this gaseous fluid stream S in the area of the inlet gaps 9a of the subsequent treatment zone 7 is likewise preferably heated to this temperature range 12, i.e., so that the gaseous fluid stream S is preferably intended to be heated to the temperature which corresponds to the temperature of the gaseous fluid (usually air) flowing around in the subsequent treatment zone 7. In this case, the heated gaseous fluid stream S should preferably differ less than 20 C., in particular less than 15 C., less than 12.5 C., and in particular less than 10 C., 8 C., 6 C., 5 C., 4 C., 3 C., 2 C. or 1 C. from the respective temperature of the gaseous medium in the adjacent treatment zone.

[0071] One possible implementation of the invention is shown in greater detail with reference to FIG. 3. In the variant according to FIG. 3, a neutral zone 7n, which is likewise delimited by a housing arrangement 31, is again provided between adjacent leading and trailing treatment zones 7.

[0072] Within this housing arrangement for the leading, adjacent zone 7 (in the extraction direction A), a schematic cross-sectional view shows a first nozzle arrangement 15v with a nozzle device 17v with nozzle outlet openings 19v as well as, adjacent thereto, a further trailing nozzle arrangement 15n with a nozzle device 17n arranged next to to the subsequent inlet slot 9a of a subsequent zone 7, which has a nozzle outlet opening 19n.

[0073] The nozzle arrangement 15 and/or the nozzle outlet opening (19v, 19n) is designed such that it extends over the entire width of the material web 1 or deviates by less than +/20% and in particular by less than +/10% therefrom.

[0074] The arrangement isas described above with reference to FIG. 2oriented in order to generate a corresponding gaseous fluid jet S at an angle to the adjacent shutter boundary wall 11.

[0075] The gaseous fluid flow S moved forward as far as the film level E via the respective boundary edge 113 of the shutter or shutter plate 113, the distance of which from the material web 1 is adjustable, is then deflected as indicated by the arrows 33a and 33b. The gaseous fluid id stream S, which is generated by a leading nozzle arrangement 15v with respect to an upstream treatment zone 7 in the extraction direction A of the plastic film, is deflected in the extraction direction A of the film according to arrow 33b, and then, optionally, away from the material web plane E approximately in the central region of the neutral zone 7n, specifically as far as an extraction device 35, which is remote from the material web.

[0076] The gaseous fluid flow S produced by the subsequent zone in the extraction direction A, while avoiding entry through the inlet gap 9a, moves into the following zone 7 in the opposite direction to the extraction direction A of the film in the neutral zone 7n, until it is also is moved away from the film plane E approximately in the central region of the neutral zone 7n according to the arrow 33a, specifically as far as the likewise aforementioned extraction device 35.

[0077] The two extraction devices 35 can be chosen to be very different in their design and arrangement.

[0078] With reference to a further schematically shown exemplary embodiment based on FIG. 4, it is illustrated that, on each side of the web 1, instead of, for example, an extraction device 35 placed remotely in common with the film plane E, a separate extraction device 35a or 35b may be provided for each nozzle arrangement, which separate extraction device, for example, is arranged remotely from the film plane E, on the rear side of the respective nozzle assembly 15. The path of the extraction and the flow direction of the gaseous fluid flow S is similar in both cases, however, since the leading nozzle arrangement 15v arranged in the extraction direction in the neutral zone 7n generates a fluid flow which initially runs in the extraction direction A of the plastic film, in order to be led away in the direction of the extraction device 35a, whereas the nozzle arrangement 15n (which is associated with a subsequent treatment zone 7) arranged in the subsequent neutral zone 7n flows initially opposite to the film extraction direction A along the film plane E, in order to then be deflected in the rear area behind the nozzle box, where the corresponding extraction device 35b is arranged.

[0079] Finally, it should be further added in regard to the exemplary embodiments of FIG. 3 and FIG. 4 that, in the neutral zone 7n, the nozzle and extraction devices are preferably also housed in the aforementioned housing device 31, said devices also comprising, for example, neutral zones and walls 113a and 113b which are also offset relative to one another in the extraction direction A, said zones and walls being arranged on the inlet side and outlet side relative to the extraction direction A of the material web 1. These neutral zone walls 113a, 113b preferably extend parallel to the respectively adjacent chamber inlet or chamber outlet walls 11a, 11b, even ifas shown in FIG. 3 and FIG. 4the predominant height of said walls exhibits a lateral distance relative to one another in the extraction direction A.

[0080] Preferably, at least in a partial height adjacent to the plane E, a wall section is then provided, which can either be part of a chamber wall 11a, 11b of a zone 7, and/or part of the neutral zone walls 113, i.e. specifically of the neutral zone walls 113a, 113b. This wall section is then applied to the film plane E to the extent that the respective inlet gap 9a or outlet gap 9b is formed between the opposite boundary edges 13.

[0081] With reference to FIG. 5 and FIG. 6, it is then shown schematically in the form of a disc-shaped sectional view with respect to a nozzle assembly 15 that the gaseous fluid stream S can, for example either via a slotted nozzle 37a or a hole nozzle arrangement 37b escape slightly obliquely in the direction of the shutter wall 11 and/or shutter plate 113, in other words being blown out in this direction, in order to then flow along the shutter boundary wall 11 and/or the neutral zone wall 113 parallel thereto and over the shutter or shutter plate seated there, and away in the direction of the film plane E (as indicated by the arrow S), whereby, in FIG. 5 and in FIG. 6, half the gap height H.sub.1/2 is still indicated. Gaseous fluids located in an upstream zone 7 could escape therethrough, which is intended to be prevented by the shutter device. In practice, the fluid flow S will indeed run over its path in a direction predominantly perpendicular to the plane E, but, in the region of the gap opening to the adjacent leading or trailing zone possibly, it will be slightly obliquely deflected with respect to the plane E of the material web 1.

[0082] In FIGS. 5 and 6, an extraction region 39 is also shown, which, for example, corresponds to the extraction opening 39 in the extraction device 35. In the variant according to FIG. 5 and FIG. 6, the extraction opening 39 is arranged at the level of the nozzle opening 37a and 37b in order to make it clear that the extraction opening 39 can be provided in a different construction for the various variants of the extraction device 35, for example in the neutral zone 7n. The aforementioned nozzle openings may also be formed higher or lower, so that the extraction openings 39 are then located at a different height relative to the nozzle opening.

[0083] The nozzle arrangement is such that the gaseous fluid flow at the height of the material web 1, or at least also at the level of the inlet or outlet gap 9a, 9b, extends so broadly in the transverse direction of the material web 1 that the fluid flow impinges onto the material web 1 across the entire width, while covering about half the gap on each side of the remaining material web, so that the respective inlet or outlet gap is covered by this gaseous fluid flow and thus is virtually closed by this gaseous fluid flow. Therefore, the nozzle arrangement is provided or arranged in the transverse direction over the material web 1 with a width such that the gaps are completely covered by the fluid flow. However, it is also possible that the outlet nozzles are provided and/or formed only in a smaller width relative to the material web, but then being split in such a flat or fan-shaped manner that the fluid flow, at least at the level of the inlet and/or outlet gaps 9a, 9b, is so fanned out that the gaps are essentially closed by the gaseous fluid flow to be moved to the material web.

[0084] In contrast to FIGS. 5 and 6, FIG. 7 shows a variant in which a corresponding nozzle arrangement comprises both a slotted nozzle 37a and a preferably parallel hole nozzle 37b.