DE2056292A1 - Blown plastic film - machine for flattening and take-off from moulding head - Google Patents

Abstract

Plant for the production, flattening and take-off of blow-moulded plastic film, having an upwardly directed blow-head connected to the outlet of a screw extruder, and a film-flattening assembly incorporating squeeze rolls arranged at the required distance from the blow head to provide an adequate cooling path, has an auxiliary flattening device vertically above the blow head on each side of the line of solidification of the tubular film downstream of a system of deflector rolls for deflecting the film through 180 degrees, with grooves permitting the passage of the blow air, the principal flattening assembly being situated with its squeeze rools spaced from and directly below the outlet of the deflector rolls.

Description

System for manufacturing, laying flat and peeling off blown plastic films In the production of plastic hose films in the blow molding process is used for high-performance systems as the forming tool downstream of the screw press, generally a vertical one upward working die used. tie horizontal guidance of the still plastic Tubular bias is out of the question because of the force of gravity acting on one side and a blow head working vertically downwards dare of the film weight that would lead to the blown tube on the blow head fitting tearing off.

Between the blow head and the lay-flat and discharge device A cooling section must be available for the tubular film for the tubular film which in high-performance systems with high take-off speeds is a considerable Length. This results in that, for the reasons mentioned before, it is vertical must be blown upwards, the need for a great height of the production hall, which is caused solely by the blown film line, while the possibly downstream processing machines no special space requirements in sen] real Have direction.

The invention is based on the object of proposing a blown film line, a reduction when using a blow head that works vertically upwards the required hall height or, if the hall height is given, an extension of the Allowing cooling section and thus an increase in the withdrawal speed.

According to the invention, this object is achieved in a system for producing Laying flat and peeling off plastic blown film with one of the screw presses downstream, at least vertically upward working blow head and distance the required cooling section from the blow head arranged flattening device solved with squeeze rollers that perpendicular to the die beyond the Film solidification line an auxiliary flattening device is arranged, the one Downstream deflection device for deflecting the tubular film by 180 °, wherein On the deflection of the deflection roller or rollers, grooves are provided for the blown air to pass through are, and that the main flattening device with the squeegee rollers at a distance is arranged from and vertically under the discharge side of the deflection device.

In the system designed according to the invention, before and a tube bladder from behind the deflection device, because the tube bladder forming air due to the presence in the deflection roller or rollers of the deflection device Grooves in the hose part between the deflection device and the squeegee rollers can enter and expand it. The Stretch from the first deflection roller to the taupt flat leaflet plates. This allows the desired substantial reduction in reach the necessary mall.

The deflection device can advantageously consist of two deflection rollers, between which a support device with rollers to keep the inflating ones flat Fglienbahn is arranged more intensely. To the deflection device / for the seating of the To use the film tube, these rollers can be water-cooled. Instead of the water-cooled auxiliary rollers can also be flat between the two deflection rollers ühlroste or plates can be provided. Finally, the two guide rollers can also be used having deflecting device be enclosed by an air duct, preferably in the dcn cooling air is blown in countercurrent.

The arrangement according to the invention is particularly advantageous in systems in which the lay-flat and take-off device are used to distribute the during manufacture of films made of thermoplastic plastics is known to be unavoidable longitudinal thickness error continuously or reversing around the hose axis turns. Without the relative rotary movement between the film die head on the one hand and the lay-flat and take-off device on the other hand would be when winding the Foils as a result of the constant thickness fluctuations on the roll across the width by adding the thick spots, they form annular beads that cause a permanent deformation the slide in this.

Cause areas. By continuous or reversing In the movement of the film take-off, the thickness errors of the film in the manner of rope winding are determined distributed on a drum over the entire width of the roll so that cylindrical Wraps without annular beads arise.

To achieve the required relative rotary movement between On the one hand, the blow head and take-off device are known to continuously operate the blow head or to rotate in reverse. In this case, however, thickness errors are only generated in the die itself distributed and not those that are due to spatial influences, for example one-sided Cooling, given or already stapimen from the screw press.

Another known possibility for generating the curved relative rotational movement consists in the lay-flat plates and squeegee rollers, preferably reversing to rotate and the downstream film winder also on the turntable to be attached so that the film winder together with the lay-flat plates and Abguetschwalzen is rotated. In the previous design of the blown film line with on the Hall floor standing extrusion press and take-off-winder combination standing on a revolving platform Problems arose from the fact that the mostly very difficult polishing roles after the Completion had to be lowered onto the hall floor.

In addition, the intermediate stage had to be designed in such a way that it large weight of the winding device and the finished winding could take. the Power supply and control lines had to be connected to the one on the hall floor standing screw press and on the other hand to the arranged at a considerable height, rotatably mounted take-off and winding device are performed.

In contrast, in the case of the plant according to the invention, according to a further Proposal, the main flattening device is rotatably mounted and its one essentially rotatable take-off and trickle device arranged in the same plane as the extruder downstream, all these disadvantages are avoided.

As a result of the inventive deflection of the tubular film in a direction opposite to the blowing direction of the blow head, parallel with flattening of the hose is only in this downward part of its trajectory it makes it possible to arrange the winder on the hall floor so that removing the finished film rolls, taking up the weight of the winding device and the finished winding and the supply of the necessary drive and control energy no one causes trouble. On the arranged above the extruder Intermediate stage, only the deflection device and the intermediate stage are available therefore - apart from the first pulling in of the film tube - does not need to be committed.

Since this arrangement of the rotary take-off winder is different than with the usual systems, a film tube section without twist-sensitive The plastic zone is pulled off by turning and laid flat - because the twisting effect the rotating flattening device does not go beyond the deflection device up to the still soft plastic film part located immediately behind the blow head can continue - can with particular advantage the speed of rotation of the rotatable Take-off winder can be coupled with the take-off speed, so that the degree of twisting found to be beneficial for the film tube without edge wrinkling remains the same at all take-off speeds without the operating persona? Need to make corrections, this will result in lower take-off speeds Edge folds and, at higher take-off speeds, bulges on the roll; those at relative low rotational speeds are avoided. After another Embodiment of the invention the transmission ratio between the rotary and the The withdrawal speed can be adjusted.

It is also proposed according to the invention for supporting, calibrating and cooling the two inflated parts of the tubular film according to an older proposal of the applicant to use trained support or cooling ring segments, Several of them together enclose the hose and for adaptation are radially adjustable to different desired hose diameters. the Guiding the hose in the downward part of its trajectory up to shortly before the rotatable flattening device has the particular advantage that the flattened Hose is wound up on the roll without lateral offset, so that on a side edge control can be dispensed with. Those formed from the individual support segments are advantageous Support and cooling ring for the hose parts moving in opposite parallel directions adjustable by means of a common diameter adjustment device in the event of format changes.

It is already known to have a reversing one vertically above the blow head To arrange lay-flat and pull-off device, which the laid-flat tubular film feeds it to a stationary tlickler via a suitably designed turning bar system, wherein the winding device can also be arranged on the hall floor. By the weneestand system arranged on the reversing trigger mechanism enlarged the already large take-off height in high-performance blown film lines still considerable.

Besides that, it was not possible without an additional side edge control to produce exactly the side edge straight winding, because due to the large distance from the reverse-boiling take-off up to the winder through the moving back and forth across the width of the film Thick places the film web is caused to lateral deflections in this way This turned out to be particularly disadvantageous when the tubular film was wound up before being wound up Slit on the side and wound up as a flat film using a double winder became.

The idea of the invention makes it possible to also take advantage of the power to avoid known devices of the type described with turning bar systems. For this purpose, according to the invention, the main lay-up device is again rotatable, and although in this case necessarily reversing, stored and you one essentially stationary take-off winder arranged in the same plane as the extruder downstream, which the film over a known turning bar device is fed. The reduction of the space requirement in the vertical direction errj.Dt ricn. also here from the inventive idea of deflecting the tubular film before the final flattening. Since the reversing lay-flat device on the Frame of the film winder itself can be attached, with between the The flattening device and the film winder still have the turning bar system, the film web can no longer run down to the film roll, so that even without side edge controls exactly straight-edged film wraps are created. In addition, the advantages of the arrangement of the film winder that have already been described result on the hall floor. In this embodiment, too, the coupling is the rotational speed the reversing lay-flat device with the take-off speed possible and advantageous.

In a further development of the last-described embodiment the invention can be a stationary pair of take-off rollers - with a non-driven pair of squeegee rollers - Be provided in the film direction behind the turning bar system, with a The roller of the stationary pair of take-off rollers is also the contact roller for driving the Can form film winding. So there is the additional considerable advantage that a special winder drive is saved.

The invention is in the following description with reference to two Embodiments explained in more detail, which are shown in the two figures of the drawing are.

From the extrusion press 1 shown in FIG. 1 with the blow head 2 the film tube 3 is formed. After the hose 3 has cooled down Cooling devices not shown, the hose is through the stationary auxiliary flat plates e laid flat and through the roller 5 provided with the grooves 6 to the side to one second deflection roller 7 deflected with the grooves 8, which in turn put the flat Slide 3 'down again - opposite to the original direction of travel of the Foil tube 3 - conducts. Through the grooves 6, 8 in the rollers 5, 7 can Propagate the fllasdrudk past the rollers 5, 7 into the flattened film web 3V. Auxiliary rollers 9 prevent a disruptive, because it is too far, between the deflection rollers 5, 7 going AuEblëhen the film web 3 ', while behind the second roller 7 the Foil web expands again to form the tube 3 2 '. The auxiliary rollers 9 can at the same time can be used as a film after-cooling device by acting as water-cooled rollers m, are formed. Instead, flat cooling grids or plates can also be used Find.

The re-expanded hose 3 'then preferably enters the reversing rotating actual take-off device with the take-off rollers 10, the Flat lay plates 11 and the co-rotating winding device with a contact @ roller 12 and the roll 13, which are arranged in the frame 14 with the pivot bearing 15 are and their reversing rotary movement indicated by the double rotary arrow 16 is. The rotation of the rotary bearing 15 is carried out in a known manner by a geared motor with limit switch reversal, preferably to 3600 in each direction.

To simplify the role change, it is advantageous if the full rolls with hydraulically braked depositing arms 17 on the floor or on trough trolleys can be set up.

The film tube is made using a calibration device and then guided by means of a hose cooling device, the features of which are the subject of older Patent applications of the applicant are. The first hose section 3 is in the area the film solidification line 18 by i risb lumbar-like adjustable in diameter 5 support ring segments 19 with easily rotatable covering supported and calibrated, which are in the frame 20 arranged accordingly adjustable and by means of the carrier 21, for example are attached to the upper stage 22, on which the hose deflection 4-9 is appropriate. By a similarly designed hose cooling device that ans parts of the support ring segments 19 has water-cooled pipe segments 23, is the hose section 3 ″ cooled and above all axially above the rotatable A5zug-WicklerkoShination 12 - 17 out so that the hose laid flat on the winding 13 does not experience any lateral offset. The cooling tube segments 23 are in turn appropriately adjustable in the frame 24 and attached to it by means of the carrier 25 the stage 22 attached.

This arrangement makes operation considerably easier, if both systems have a common diameter adjustment device in the event of format changes can be adjusted, indicated schematically by the adjusting shaft 26 and their connection to the iris diaphragm-like adjustable according to the older proposal Hose guide devices 19 - 21 resp.

23-25 is represented by the dash-dotted lines 27.

In the embodiment according to FIG. 2, basically the same Structure as in the embodiment according to FIG. 1 - the winding device is stationary arranged and with a known turning bar system for supplying the Flattened tubular film from the reversing flattening device to the stationary one Tickler provided. The matching with the embodiment of FIG Parts of the overall system have the same reference numbers and are used below not explained again.

As can be seen from the drawing, it differs from the first exemplary embodiment the essentially herizontal area of the areas held flat by the auxiliary rollers 9 tubular bladder 3 'enclosed with a rectangular air duct 28, in which preferably in countercurrent cooling air 29 is blown by the fan 30.

The re-expanded hose 3 ″ then enters the reversing one actual lay-flat device with the non-driven squeegee roller 31, the flat lay plates 32 and the tJend pole system that swings out to the side in a fan-like manner 33. The Flachlecre plates 32 and the squeegee rollers 31 are shown schematically by the indicated gear motor 34 pivoted back and forth through 360 °, as indicated by the double rotary arrow / is, where i is the individual deflection axes of the turning bar system 33 to from top to bottom decreasing amounts are swiveled at the bottom. The characteristics of this Use particularly advantageous turning bar device are the subject of a @ Applicant's previous patent application.

The reversing lay-flat device 31 to 35 is by means of Frame 36 is arranged on the winder 37, on which, for example, a pressure pretreatment station 38 and / or a slitting device known per se for production of flat film using a likewise known per se for this purpose Double winder can be attached. With the large winding diameters of the winding 39 from about 1.5 to 2 m and the resulting height of the reversing flare device A small operating platform 10 is expediently above the hall floor for to provide this area.

With this overall arrangement, there is the advantage that it can be done as usual driven pair of take-off rollers 41 can be arranged directly on Wi winding 39, so that one of the take-off rollers 41 is also the contact drive roller for the film roll 33 forms and the otherwise required special winding motor can be omitted. pre-condition is, however, that the length of the film between the The die head and the take-up point are not changed periodically. This is when applying of the t'endt: rod system of the Applicant guaranteed.

Claims (12)

Patent claims 1. System for producing, laying flat and pulling off plastic blown films with one downstream of the screw press working vertically upwards Blow head and one at least at a distance from the required cooling section Blow head arranged flattening device with squeegee rollers t characterized that vertically above the blow head (2) beyond the film solidification line (18) a Auxiliary flattening device (1) is arranged, which has a deflection device (5,7) for deflecting the tubular film (3) is connected downstream by 1800, with the deflection roller or the deflection rollers (5,7) grooves (6,8) are provided for the blown air to pass through are, and that the main flattening device (11,32) riit the squeegee rollers (10,31) arranged at a distance from and vertically under the discharge side of the deflection device is. 2. Plant according to claim 1, characterized in that the deflection device consists of two guide rollers (5,7), between which a support device with rollers (9) is arranged to keep the inflating film web (3 ') flat. 3. Plant according to claim 2, characterized in that the rollers (9) are provided with water cooling. t. Plant according to claim 2, characterized in that between the two deflection rollers (5,7) level cooling grids or 5 :? slats are provided. 5. Plant according to claim 2, characterized in that the film web (3 ') is enclosed in the deflection device by an air duct (28), in which preferably ir.- countercurrent I <ühlluft t29) is blown in. 6. Plant according to one of claims 1-5, characterized in that the main flattening device (11) is rotatably mounted and essentially one of it in the same plane as the extruder (1) arranged rotatable take-off device Y: ricklervorrichtung (10,12,13> is connected downstream. 7. Plant according to claim 6, characterized in that the rotational speed the rotatable take-off winder is coupled to the take-off speed. 8. Plant according to claim 7, characterized in that the transmission ratio can be set between the rotation speed and the withdrawal speed. 9. Installation according to one of claims 1-E, characterized in that for supporting, calibrating and roughening the two inflated parts of the tubular film (3.3 '') support or cooling ring segments (19, 23) are used, each of which several together enclose the hose and to adapt to different desired hose diameter are radially adjustable. O. Plant according to claim 9, characterized in that the from the individual support segments (19,23) formed support and cooling rings for the opposite hose parts (3.3 ") moved in parallel direction by means of a common flow adjustment device (26,27) are adjustable in the event of format changes. 11. Plant according to one of claims 1-5, 9, 10, characterized in that that the main lay-flat device (32) is rotatably mounted in a reversing manner and its one substantially in the same plane as the extruder (1) arranged place fixed take-off winder device (39,41) is connected downstream, which the film (3) is supplied via a known turning bar device (33). 12. Plant according to claim 11, characterized in that a stationary Pair of take-off rollers (41) in the direction of film travel behind the I-end rod system (33) is provided while the pair of squeezing rollers (31) is not driven, wherein one roller of the stationary pair of take-off rollers (41) is also the contact roller for Forms drive of the film roll (39). Blank page