Temperature adjusting device and blown film production line with same

Abstract

The invention relates to a temperature control device (20) for controlling the temperature of a film tube (1) extruded in a traction direction above a frost line (14), comprising a plurality of guide sections (21, 21 ', 21' ') which are distributed around a longitudinal axis (L) arranged parallel to the traction direction of the film tube (1) and form a central guide opening for guiding the film tube along the longitudinal axis, the guide section can be transversely adjusted relative to the longitudinal axis so as to adjust the diameter of the guide opening; each guide section is provided with a guide roller (22) which can be adjusted together with the guide section and is intended to guide the extruded film tube (1); and a nozzle section (23, 23 ', 23' ') associated with the guide roller, the nozzle section being adjustable together with the guide section, the nozzle section having an outlet nozzle (45, 45') which is designed to blow out a temperature control gas in the direction towards the longitudinal axis, characterized in that the nozzle section is arranged at least partially radially overlapping the guide roller with respect to the longitudinal axis.

Description

Technical Field

[0001] This invention relates to a temperature control device for controlling the temperature of a film tube extruded along a traction direction above a frost line. The device includes a plurality of guide sections distributed around a longitudinal axis parallel to the traction direction of the film tube, forming a central guide opening for guiding the film tube along the longitudinal axis. These guide sections are laterally adjustable relative to the longitudinal axis to adjust the diameter of the guide opening. Furthermore, each guide section has a guide roller, which is adjustable together with the guide section for guiding the extruded film tube. Nozzle sections assigned to the guide rollers are adjustable together with the guide sections, and these nozzle sections have nozzles configured to blow out temperature-regulating gas in a direction toward the longitudinal axis.

[0002] Furthermore, the present invention relates to a blown film production line, wherein the blown film production line includes a blown head and a cooling gas ring located downstream of the blown head along the traction direction. The blown head is used to push a film tube made of plasticized thermoplastic material along the longitudinal axis in the traction direction. The cooling gas ring forms a central opening for the plasticized film tube to pass through and has at least one internal outlet nozzle for supplying cooling gas to flow onto the film tube, thereby causing the film tube to change from a plastic state to a solidified state at the frost line. Background Technology

[0003] DE 20 2023 101 698 U1 discloses such a temperature control device and a blown film production line. In the temperature control device shown in this patent, the guide roller and the nozzle section are arranged one after the other along the traction direction. The nozzle section is designed in the form of a blow-out beam attached to a pivot arm. The guide roller is also attached to the pivot arm.

[0004] DE 23 57 138 A1 discloses a post-cooling device for blown films made of thermoplastic plastic, the device having at least one cooling gas ring disposed outside a frost line, the cooling gas ring having a plurality of air outlet openings pointing toward a film tube, the film tube being composed of a plurality of individual blown elements, each blown element being pivotally connected to each other in pairs about an axis extending perpendicular to the longitudinal axis at its adjacent ends, and being radially adjustable relative to the longitudinal axis. The post-cooling device is arranged on a calibration basket by means of which the film tube is centered and guided.

[0005] EP 1 491 319 A1 describes a blown film production line including a gas suction device surrounding a film tube downstream of a calibration basket, having substantially annular suction nozzles for extracting monomer evaporates. Immediately above (i.e., downstream) of the gas suction device, outside the film tube, is a temperature control device in the form of another cooling gas ring, designed to have a rigid ring with a fixed and unchangeable inner diameter through which the film tube passes.

[0006] In blown film production, thermoplastic material is extruded through an extruder into a blown head with a ring die or channel, forming an upwardly pulled film tube. The heated film tube is exposed to internal overpressure and, immediately after exiting the annular nozzle, is cooled by blowing cooling gas from the outside, and possibly from the inside, in a substantially annular shape. After the expansion phase of the film tube, the thermoplastic material largely solidifies as it leaves the ring die, after which the diameter of the film tube remains essentially constant. This point of solidification is called the frost line or freezing point. After solidification, the film tube is fed lengthwise via a calibration basket and a flattening unit, and is compressed and pulled as a flat tube by a traction unit. The calibration basket is positioned above the frost line. The diameter of the film tube, and subsequently the film width, can be varied by adjusting the internal overpressure within the film tube and the setting of the adjustable calibration basket.

[0007] An additional cooling gas ring can be used to cool the relatively warm film tube before it enters the flattening unit, reducing the risk of the film layers clogging (adhering to each other) in the traction unit after the film tube is folded. This means that when the film layers are wound onto multiple rolls or during subsequent processing, it is impossible or difficult to separate the film layers from each other.

[0008] In known blown film production lines, there is a risk that the film tube may not be centered when it is fed into the flattening unit (clamping unit, collapse unit) and traction unit. Furthermore, this off-center position of the film tube changes continuously during production. This can lead to wrinkles or edge misalignment in the folded film tube, for example.

[0009] During the extrusion of film tubes, certain formulations and products can cause so-called flatness errors in the produced film. Such flatness errors include, for example, waviness with any distribution, sagging in edge areas, and so-called camber.

[0010] This error is clearly visible when the film is unwound from the finished roll and laid out on the floor without tension. Simply put, flatness error is a localized deviation in length of film across the width of the web.

[0011] These defects can usually be visually detected in the film web under tension, either during the journey from the traction machine to the winding machine or inside the winding machine.

[0012] In the region where the film tube remains circular, a heating sleeve device is known that uses infrared radiation heaters arranged in a fixed diameter to reheat the film tube above the frost line in order to improve the flatness quality of the subsequently flattened film. This utilizes the effect that the uneven stress distribution caused by the different molecular orientations at the periphery of the film tube and the resulting local length differences are reduced again by reheating, thereby significantly reducing or completely preventing flatness errors in the flattened (collapsed) film.

[0013] Uneven stress distribution is mainly caused by flow effects in the extrusion (hard) die of the blow molding head, such as by flow channel design that is not optimally matched with the raw material, by unsuitable heating profile of the extrusion die, or by uneven circumferential temperature and / or circumferential volume distribution of the melt inside the extrusion die and at its outlet.

[0014] In addition, flatness errors can also result from setting the calibration basket at a height that does not match the frost line of the film tube, excessive contact pressure (fill level) in the calibration basket, or the calibration basket being slightly off-center relative to the extrusion die.

[0015] A disadvantage of the heating jacket setup is the rigid arrangement of the radiant heaters, as various different membrane bubble diameters are typically produced. The variable distance between the membrane and the heating jacket is also an additional influencing factor, alongside actual production parameters. Summary of the Invention

[0016] The purpose of this invention is to provide a temperature control device and a blown film production line that enables the most efficient and variable temperature control, wherein the temperature control device has the lowest possible overall height in the longitudinal axial direction.

[0017] The problem is addressed by a temperature control device for controlling the temperature of a film tube extruded along the traction direction above a frosting line. This device includes multiple guide sections distributed around a longitudinal axis parallel to the traction direction of the film tube, forming a central guide opening for guiding the film tube along the longitudinal axis. These guide sections are laterally adjustable relative to the longitudinal axis to adjust the diameter of the guide opening. Furthermore, each guide section has a guide roller, which is adjustable along with the guide section for guiding the extruded film tube. Nozzle sections assigned to the guide rollers are adjustable along with the guide sections, and each nozzle section has a blow-out nozzle configured to expel temperature-regulating gas in a direction toward the longitudinal axis. The nozzle sections are arranged relative to the longitudinal axis to at least partially overlap the guide rollers radially.

[0018] Therefore, viewed radially, the nozzle section at least partially covers or overlaps the guide roller. This overlapping arrangement of the nozzle section and guide roller in the longitudinal direction reduces the overall height of the temperature control device along its longitudinal axis. In this way, two functions are achieved within a very small overall height: temperature control of the film tube and guidance of the film tube. Therefore, this temperature control device is much more compact than conventional temperature control devices.

[0019] This is particularly important because installation space in the traction direction, i.e., in the direction of the longitudinal axis, is often limited by factors such as lower plant height or other system components. For other reasons, a low overall height of the entire blown film production line may also be desirable, for example, as this can have a positive impact on the system's cost.

[0020] On the other hand, compared to traditional blown film production lines, additional sensors or system components can be arranged within the installation space without reducing the overall height of the blown film production line, or the reduction in height is less than theoretically possible. Furthermore, the gained installation space can be used to arrange more guide layers with additional guide sections, thereby improving temperature control performance compared to traditional temperature control units.

[0021] Because the guide section can be adjusted laterally relative to the longitudinal axis to set the diameter of the guide opening, efficient and variable post-temperature control can be achieved. This ensures that the blow-out nozzle is always positioned at the optimal distance from the produced film tube, regardless of the diameter of the film tube being produced.

[0022] The diameter of the guide opening is the maximum possible diameter of the imaginary circle inside the adjustable guide roller.

[0023] The nozzle segment may be arranged at least partially radially outward of the guide roller relative to the longitudinal axis. The nozzle segment may also be arranged completely radially outward of the guide roller. Alternatively, it is conceivable that the nozzle segment, in addition to radial overlap, is also partially arranged to overlap axially with the guide roller. This means that, when viewed in the axial direction, the nozzle segment at least partially covers or overlaps the guide roller. This may occur on one side of the guide roller relative to the traction direction, or on both sides of the guide roller. This means that at least one segment of the nozzle segment is arranged upstream and / or downstream of the guide roller and overlaps axially with the guide roller.

[0024] By axially overlapping the nozzle section with the guide roller, the blow-out nozzle can be positioned at a smaller distance from the film tube than in the case of no axial overlap, thereby improving cooling capacity.

[0025] To achieve the most compact design possible, the nozzle segment can be specified to have a maximum height in the direction parallel to the longitudinal axis. This maximum height must exceed the entire length of the blow-out nozzle, at least 50% of the blow-out nozzle length, or at least 25% of the blow-out nozzle length. This height is at most equivalent to 2.0 times, 1.5 times, 1.25 times, or 1.0 times the height of the guide roller. The height of the nozzle segment in the circumferential direction around the longitudinal axis can vary; therefore, this refers to the maximum height in the circumferential direction.

[0026] In order to achieve the most compact design of the temperature control device, the guide rollers can be arranged to be offset from each other in height in the direction of the longitudinal axis and in the circumferential direction of adjacent guide sections, and the guide openings can at least partially intersect each other in the direction of the longitudinal axis and in the plan view, at least when the diameter of the guide opening is less than a predetermined value.

[0027] To achieve the most compact design possible, it can be specified that the nozzle segments of intersecting guide sections have a maximum height in the direction of the longitudinal axis, at least in the area where the guide sections intersect or may intersect, which is at most equivalent to 2.0 times, 1.5 times, 1.25 times or 1.0 times the height of the corresponding guide roller.

[0028] Specifically, if the nozzle section overlaps axially with the guide roller, the blow-out nozzle can be designed to allow the temperature-regulating gas to flow out at a 90° angle to the longitudinal axis. However, it is advantageous to design the blow-out nozzle such that the temperature-regulating gas has at least one flow vector along and / or against the traction direction, which forms an angle of less than 90°, less than 60°, or less than 45° with the longitudinal axis. In particular, at least one flow vector can be guided away from the guide roller to prevent the temperature-regulating gas flow from being affected by the guide roller or to prevent the diaphragm tube from being lifted off the guide roller.

[0029] The nozzle section may have multiple blow nozzles, which are arranged adjacent to each other in the circumferential direction and / or arranged back and forth in the axial direction, for example.

[0030] It can be specified that at least one blow nozzle is aligned along the traction direction, and at least another blow nozzle is aligned against the traction direction.

[0031] The nozzle section can be an integral part (integrated part) of a guide section. Alternatively, the nozzle section can be envisioned as a separate component connected to the guide section.

[0032] Each guiding element may have multiple guiding rollers.

[0033] Multiple nozzle segments can be assigned to each guide roller. It is also possible to assign multiple guide rollers to a common nozzle segment.

[0034] The temperature control device may have a frame to which a guide section is adjustablely hinged to set the diameter of the guide opening. This frame may be designed as a separate unit from other system components of the blown film production line.

[0035] The temperature control device can be designed to heat and / or cool the diaphragm tube. Therefore, the temperature control device can have a cooling unit for cooling the temperature-controlled gas and / or a heating unit for heating the temperature-controlled gas.

[0036] To reduce or prevent films from sticking together (clogging) during folding, the film tubes can be post-cooled using a temperature control device. This means that blown film production lines can operate at higher output rates, i.e., at higher film tube traction speeds, without the risk of the film tubes being fed to the flattening unit while overheated and at risk of clogging. Therefore, the output rate, i.e., the amount of film produced per unit time, can be increased. Furthermore, the use of additives in plastic materials to reduce clogging tendency can be reduced or even eliminated. Besides cost savings, reducing additives can also positively impact the lifespan of the extruder screw or the extruder itself. Additives used to reduce clogging tendency often include mineral fillers, which can lead to increased wear on extruder components, especially the screw.

[0037] However, to improve the flatness of the thin-film tube, it can be reheated using a temperature control device to reduce the uneven stress distribution in the molecular structure. This improves the flatness and uniformity of the thin-film tube.

[0038] One specific advantage here is that the same temperature control device is equally suitable for cooling tubular films made of materials sensitive to blockage as for heating tubular films made of materials sensitive to flatness. This means that the temperature control device does not need to be changed when switching between materials sensitive to blockage and materials sensitive to flatness.

[0039] The temperature control device may have at least two guide layers with guide sections, arranged one above the other along the longitudinal axis and distributed around the longitudinal axis. Guide sections of multiple guide layers may be arranged around the periphery such that at least two guide sections are always arranged one above the other along the longitudinal axis. For each guide layer, the guide sections may be arranged identically such that the distance between the guide sections of two guide layers is the same. In practice, it has been shown that at least two guide layers or two rollers with guide sections arranged one above the other are advantageous for stably guiding the thin film tube. The rollers do not necessarily need to be axially aligned with each other, but this simplifies the actuation mechanism of the guide sections.

[0040] The temperature control device may have an adjustment unit by which the guide section can be laterally adjusted relative to the longitudinal axis, such that the corresponding guide roller is moved centered relative to the longitudinal axis. For this purpose, the temperature control device may have a frame through which the film tube can be guided along the longitudinal axis. Each adjustment unit may include a pivot arm pivotally attached to the frame, a bracket for the guide roller, and a coupling pivotally connected to the bracket, wherein the bracket is pivotally connected to the pivot arm. Furthermore, at least one of the adjustment units includes an actuation mechanism by which the connecting rod of at least one adjustment unit can be pivotally connected to the frame. This arrangement allows the guide roller to be precisely centered on film tubes of various diameters with minimal construction work. Details of the various adjustment units are shown in WO 2020 / 244737 A1, the contents of which are incorporated herein by reference.

[0041] Furthermore, this objective is achieved by a blown film production line, which includes: a blown head for ejecting a film tube made of plasticized thermoplastic material along a longitudinal axis in a traction direction; and a cooling gas ring located downstream of the blown head in the traction direction, the cooling gas ring forming a central opening for the plasticized film tube to pass through, and having at least one internal outlet nozzle for flowing cooling gas onto the film tube, thereby causing the film tube to change from a plastic state to a cured state at the frost line. The blown film production line has a temperature control device as described above, which is designed to be located downstream of the frost line.

[0042] The blown film production line may also include a calibration basket located downstream of the cooling gas ring. This calibration basket has multiple calibration elements configured to encapsulate the film tube and form calibration openings that guide the film tube. The calibration elements are adjustable to set the diameter of the calibration openings. A temperature control device may be located downstream of and installed in the calibration basket, or it may be arranged as a separate element at a certain axial distance from the calibration basket.

[0043] According to an exemplary embodiment, the blown film production line includes a flattening unit for folding film tubes located downstream of a temperature control device. Here, there are no components affecting the film tubes in the area between the temperature control device and the flattening unit. Attached Figure Description

[0044] Exemplary embodiments will now be described in more detail with reference to the accompanying drawings. In the drawings,

[0045] Figure 1 This is an overall view of a blown film production line with a temperature control device according to the first embodiment, including an adjustment section.

[0046] Figure 2 It is based on Figure 1 A top-view view of the temperature control device.

[0047] Figure 3 This is a perspective view of the second embodiment of the adjustment section.

[0048] Figure 4 It is based on Figure 3 A top-view view of the adjustment section.

[0049] Figure 5 It is based on Figure 1 A side view schematic diagram of the first embodiment of the adjustment section;

[0050] Figure 6 It is based on Figure 3 A side view schematic diagram of the second embodiment of the adjustment section;

[0051] Figure 7 This is a side view schematic diagram of the third embodiment of the adjustment section, and

[0052] Figure 8 This is a side view schematic diagram of the fourth embodiment of the adjustment section. Detailed Implementation

[0053] Figure 1 This is a partial longitudinal cross-sectional side view along the longitudinal axis L of a blown film production line used to produce film tube 1. For illustrative purposes, the following figures are included, all using a Cartesian coordinate system, where the Z-axis is a vertical axis parallel to the longitudinal axis L, and the two transverse axes, the X-axis and Y-axis, span a horizontal plane. An extruder 3 is mounted on a machine base 2, on which two feed hoppers 4 and 5 for thermoplastic material are visible. The thermoplastic material, fed in granular form via the feed hoppers 4 and 5, is plasticized and homogenized in the screw of the extruder 3 by pressure and an additional heating device, and is forced into a blown head 6 adjacent to the extruder 3. The vertical axis of the blown head 6 is along the longitudinal axis L of the blown film production line. The blown head 6 has an annular nozzle 7 schematically shown on its upper side, from which the initially expanded, axisymmetric film tube 1, still made of plasticized film material, emerges. After the film material cures, the film tube 1 essentially retains its diameter. The film tube 1 is flattened in the flattening unit 8 and pulled upward by the traction unit 9. The flattened film tube 1 is then wound onto a roll (not shown here). In the direction from the blow molding head 6 to the traction unit 9, the functional terms "front" and "downstream" are used in a way that indicates "below" and "above" in terms of spatial relationship.

[0054] A cooling gas ring 10, partially schematically shown, is shown directly above the blow molding head 6. The gas supply line 11 is connected to a blower 12 on the inlet side, through which cooling gas (typically air) is supplied to the cooling gas ring 10. Ambient air is drawn in via the blower 12 for this purpose. Other cooling gases or mixtures of cooling gases may also be used. The cooling gas ring 10 has an internal outlet nozzle 13 from which the cooling gas flows and onto a film tube 1, which is under increased internal pressure and guided in a ring shape substantially parallel to the wall through the central opening 19 of the cooling gas ring 10. The flow of cooling gas from the blower 12 to the film tube 1 is indicated by arrows. The diameter of the plasticized film tube 1 in this region initially expands under the aforementioned excessive internal pressure until it solidifies under the action of the cooling gas and presents a constant diameter. The transition point from the plasticized material to the hardened material is called the "frost line" and is marked 14. The frost line 14 need not be a clear line, but can extend over a limited area along the longitudinal axis L. To generate internal overpressure, an internal cooling tower 15 is centrally mounted on the blow molding head 6, through which cooling gas is introduced into the interior of the membrane tube 1. The introduced cooling gas is discharged through the gas extraction line 16 in a manner that maintains a defined internal pressure.

[0055] Above, downstream of the frost line 14, along the longitudinal axis L in the traction direction, lies a calibration basket 17 containing calibration elements 18 with stacked roller assemblies, the calibration elements 18 being arranged substantially in a loop around the film tube 1. To accommodate film tubes 1 of different diameters, the roller assemblies are generally located on pivoting sections forming the periphery of each section, by means of which the diameter of the calibration opening in the calibration basket 17 through which the film tube 1 is guided along the longitudinal axis L can be varied. In cross-section, these sections form polygonal calibration openings. In the example shown, the calibration opening has a diameter K.

[0056] The cross-section of the still relatively warm film tube 1 is stabilized and guided by the calibration basket 17. The calibration basket 17 can be arranged in a height-adjustable manner relative to the blow molding head 6 so that it can always be in the optimal height position relative to the frosting line 14.

[0057] A temperature control device 20 is arranged downstream of the calibration basket 17 and is used to temperature control the film tube 1. The temperature control device 20 has multiple guide sections 21, each with guide rollers 22 and nozzle sections 23, arranged one above the other and distributed around the periphery of the film tube 1. The guide rollers 22 enclose the film tube 1 and form a guide opening with a diameter F. In this design example, the diameter F of the guide opening is the same as the diameter K of the calibration opening. The guide rollers 22 are particularly used to center the film tube 1 with respect to the longitudinal axis L, so that the film tube 1 is centered into the flattening unit 8 to avoid creases or misalignment of the edges. As will be described in detail below, the guide sections 21 are attached to adjustment sections that are adjustablely hinged to the frame of the temperature control device 20 so that the diameter F of the guide opening can be changed.

[0058] With the aid of nozzle section 23, the temperature-regulating gas is blown diagonally upward and downward along the traction direction onto the membrane tube 1. However, in principle, it is also conceivable to blow the temperature-regulating gas horizontally, that is, in a plane perpendicular to the longitudinal axis L, onto the membrane tube 1.

[0059] Diameters K and F are each defined as the maximum possible diameter of the imaginary circle within the adjustable elements (i.e., the calibration element 18 of the calibration basket 17 and the guide roller 22 of the temperature control device 20).

[0060] In the illustrated embodiment, the temperature control device 20 is arranged at an axial distance from the calibration basket 17. However, it is also conceivable to attach the temperature control device 20 to the calibration basket 17, or to integrate it to form a unit. Another temperature control device can be arranged downstream of the calibration basket 17 with the integrated temperature control device. Alternatively, the blown film production line may not have a calibration basket.

[0061] A suction unit (not shown in the figure) can be arranged downstream of the temperature control device 20. The membrane tube 1 is centrally guided through the suction unit and draws in the temperature-controlled gas. To remove as much temperature-controlled gas as possible before it enters the environment, a baffle assembly with multiple baffles can also be provided downstream of the suction unit. The baffles can be circular in shape, arranged transversely to the longitudinal axis L, and relatively close to the membrane tube 1 compared to the distance from the suction unit.

[0062] Temperature-regulating gas is supplied to nozzle sections 23 via blower 24. Blower 24 draws in ambient air and directs it to nozzle sections 23. For this purpose, a feed line 25 is used, which connects blower 24 to air distributor ring 26 of temperature-regulating device 20. Air distributor ring 26 is arranged in the form of a ring around diaphragm tube 1, and in the example shown around guide section 21, and is used to uniformly distribute temperature-regulating gas around its periphery. Air distributor ring 26 is fluidly connected to each nozzle section 23 via supply line 27.

[0063] A cooling unit in the form of an air cooler 28 and a heating unit in the form of an air heater 29 are arranged in the feed line 25, thereby allowing the use of an external cooling or heating source. This means that the temperature-regulating gas can be cooled or heated as needed before being supplied to the nozzle section 23. Alternatively, it is feasible to provide only the air cooler 28 or only the air heater 29. The arrangement order of the blower 24, air cooler 28, and air heater 29 can be selected as needed.

[0064] It should be noted that the blower 24, air cooler 28, and air heater 29 are shown at the level of the temperature control device 20. For this purpose, these components can be arranged in the tower frame 30 of the blown film production line (shown schematically here). However, they can also be located on the machine base 2.

[0065] The blown film production line also has a control unit 31, which is connected to the blower 24, air cooler 28, and air heater 29 to control them. Signals from multiple sensors are processed for the control system. The control unit 31 is equipped with a temperature sensor 32 in the feed line 25 for detecting the temperature of the temperature-regulating gas, a pressure sensor 33 on the air distribution ring 26 for detecting the pressure in the air distribution ring 26, a temperature sensor 34 upstream of the temperature-regulating device 20 for detecting the temperature of the film tube 1 before it enters the temperature-regulating device 20, and a temperature sensor 35 downstream of the temperature-regulating device 20 for detecting the temperature of the film tube 1 after it leaves the temperature-regulating device 20.

[0066] Figure 2 It shows according to Figure 1 A top view of the temperature control device 20, wherein, according to... Figure 1 The components of the blown film production line are labeled with the same reference numerals and described therein.

[0067] The temperature control device 20 has a frame 36 to which the movable elements described below are attached, and the frame 36 is arranged so that its height is adjustable relative to the blow molding head 6 if necessary. Additionally, an air distributor ring 28 is attached to the frame 36.

[0068] Frame 36 forms a central channel, and membrane tube 1 is parallel to... Figure 1 The longitudinal axis L shown is guided through the central channel. Six adjustment units 37 are distributed around the perimeter. The adjustment units 37 are used to adjust the adjustment section 49 in a radial direction relative to the longitudinal axis L. The adjustment section 49 supports the guide section 21 with guide roller 22 and nozzle section 23.

[0069] Each adjustment unit 37 includes a pivot arm 38 pivotally attached to the frame 36. In this case, the pivot arm 38 is pivotable about a pivot axis arranged parallel to the longitudinal axis L.

[0070] Furthermore, each adjustment unit 37 has a bracket 39, which is also part of the corresponding adjustment section 49. In the illustrated embodiment, this bracket carries six guide rollers 22 with nozzle sections 23. The guide rollers 22 are spaced apart in pairs along the longitudinal axis L and arranged to overlap in a V-shape when viewed along the longitudinal axis L. Figure 1 As shown, in the example illustrated, three pairs of these paired guide rollers are arranged one on top of the other. Each pair of guide rollers 22 forms a guide layer (horizontal). The three guide rollers 22 of different guide layers are arranged one on top of the other and overlap each other along the longitudinal axis L. A bracket 39 is pivotally connected to a pivot arm 38. In this case, the bracket 39 is pivotally connected to the pivot arm 38 about a pivot axis arranged parallel to the longitudinal axis L.

[0071] Furthermore, each of the adjustment units 37 includes a connecting rod 40 pivotally connected to the bracket 39. Finally, each of the adjustment units 37 includes an actuation mechanism by which the connecting rod 40 is pivotally connected to the frame 36. The connecting rods 40 of each adjustment unit 37 are pivotally and slidably connected to the frame 36 via a connecting element (not shown). The connecting element is rotatably connected to the frame 36. The connecting rod 40 is slidably connected to the connecting element. Furthermore, a cam follower 41 is attached to each of the connecting rods 40 and guided along a guide 42 on the frame 36 for translational movement. In the illustrated embodiment, the guide 42 is a groove in a plate 43 fixedly attached to the frame 36. However, other guiding systems are also contemplated. The guide 42 is curved in shape and adapted to ensure that the bracket 39 is always centrally aligned relative to the longitudinal axis L, regardless of the distance from the longitudinal axis L or the film tube 1. This ensures precise center alignment of the guide section 21 and the guide roller 22 relative to the film tube 1.

[0072] In principle, other actuation mechanisms, such as parallelogram devices, may also be considered, thereby ensuring that the bracket 39 is adjusted radially relative to the longitudinal axis L at least as far as possible.

[0073] Details of the various adjustment units are shown in WO 2020 / 244737 A1, the contents of which are incorporated herein by reference. Any version of the adjustment unit shown therein is applicable here.

[0074] Figure 3 and Figure 4 A different view of a second embodiment of the adjustment section 49 is shown. (Compared to...) Figure 2The components corresponding to the components of the first embodiment are designated by the same reference numerals and described therein.

[0075] Unlike the first embodiment, the guide rollers 22 arranged in pairs in a V-shape are not overlapped when viewed along the longitudinal axis L, but are arranged at a certain distance from each other, especially in Figure 4 As can be seen in the image. Furthermore, there are not three pairs of guide rollers 22 arranged one above the other, but rather two pairs.

[0076] Nozzle section 23 is attached to bracket 39 of adjustment section 49 via fixing plate 44. Each nozzle section 23 is equipped with guide roller 22. It is also possible to rotatably mount multiple guide rollers 22 on each nozzle section 23. It is also feasible to arrange multiple nozzle sections 23 along the guide rollers 22.

[0077] Each nozzle section 23 is tubular, designed for the passage of temperature-regulating gas, and is therefore an integral part of the regulating section 49. This means that no other components, such as the support arm and guide roller 22, are required to be mounted on the nozzle section 23 as separate components. However, this implementation is also feasible.

[0078] The following description will take one of the nozzle segments 23 as representative of all nozzle segments 23. Nozzle segment 23 has a blow-out nozzle 45, which is (narrow) slot-shaped and extends longitudinally along the guide roller 22. As will be explained later, nozzle segment 23 has a blow-out nozzle 45 pointing in the traction direction and a blow-out nozzle (not visible here) pointing in the opposite direction of traction.

[0079] Nozzle segment 23 serves as a support element for guide roller 22, which is connected to nozzle segment 23 via support plate 46 and mounted to be rotatable about axis of rotation D. Nozzle segment 23 can be made of plastic or metal, and in one embodiment, a 3D printing process is used. By using 3D printing or similar additive manufacturing processes (i.e., adding material layer by layer), any geometry can be created for the temperature-controlled gas passage. For example, this allows for the creation of specific geometries to ensure uniform distribution of air along the length of the air outlet nozzle 45. Furthermore, nozzle segment 23 can be manufactured monolithically, i.e., as a single piece.

[0080] Manufacturing nozzle section 23 with plastic has the following advantages: it is lightweight, has good thermal insulation to reduce energy loss, and produces low condensation at the surface when using cooled temperature-controlled gases. In particular, it uses plastics that are resistant to high temperatures and substances such as monomers released from the membrane tube.

[0081] Nozzle section 23 has a connector 47 that connects via a conduit (not shown) to a connection 48 of a bracket 39 for supplying temperature-regulating gas. The bracket 39 is hollow and guides the temperature-regulating gas to the connection 48, which is one for each nozzle section 23.

[0082] In the illustrated embodiment, the paired guide rollers 22 are arranged vertically offset from each other along the longitudinal axis L, which is parallel to the Z-axis of the Cartesian coordinate system. However, in principle, the guide rollers 22 can also be arranged in the same plane along the longitudinal axis.

[0083] Especially Figure 4 As can be seen, each blow-out nozzle 45 is slightly shorter than the associated guide roller 22. In principle, the blow-out nozzle 45 should extend at a maximum length corresponding to the length of the corresponding guide roller 22, preferably 50% to 100% of the length of the guide roller 22. This ensures that the film tube is precisely temperature-controlled in the area in contact with the corresponding guide roller 22.

[0084] Figure 5 It shows according to Figure 1 A schematic side view of the first embodiment of the adjustment section 49, wherein, according to Figure 3 The components corresponding to the components of the second embodiment have the same reference numerals and are described therein.

[0085] The diagram schematically illustrates guide sections 21, 21', 21'' with nozzle segments 23, 23'', 23'', and the corresponding guide rollers 22 associated with the film tube 1 for the three guide layers E1, E2, and E3. The nozzle segment 23 of the second guide layer E2 is similar in design to... Figure 3 The nozzle section 23 of the guide section 21 of the second embodiment of the adjustment section 49 shown corresponds to the adjustment section 49.

[0086] Nozzle section 23 has a blowout nozzle 45 aligned along the traction direction A and a blowout nozzle 45' aligned in the opposite direction to the traction direction A. Here, "aligned along the traction direction A" means that the blowout nozzle 45 is designed such that the temperature-regulating gas has at least one flow vector as described below, i.e., it is aligned along the traction direction A at an angle of less than 90° with the longitudinal axis L. "Against the traction direction A" means that the blowout nozzle 45' is designed such that the temperature-regulating gas has at least one flow vector as described below, i.e., it is aligned against the traction direction A at an angle of less than 90° with the longitudinal axis L. However, in principle, it is also conceivable that nozzle section 23 is designed such that at least one blowout nozzle is designed such that the temperature-regulating gas flows out at an angle of 90° with the longitudinal axis.

[0087] The nozzle section 23 is arranged relative to the longitudinal axis L to partially overlap radially with the guide roller 22 of the second guide layer E2. A portion of the nozzle section 23 protrudes from the guide roller 22 along the traction direction A, while another portion protrudes in the opposite direction A. In principle, the nozzle section 23 can also be designed to completely overlap radially with the guide roller 22.

[0088] In the illustrated embodiment, the maximum height of the nozzle section 23 in the direction of the longitudinal axis L is H, which is greater than the height h of the guide roller 22 in the direction of the longitudinal axis L.

[0089] In the illustrated embodiment, the nozzle segment 23 has a V-shaped profile in the direction of the guide roller 22 and slightly surrounds the guide roller 22. This means that the nozzle segment 23 is also partially arranged to radially overlap with the guide roller 22 relative to the longitudinal axis L. It is also conceivable that no axial overlap is provided. The axial overlap can also be greater than that shown in the illustrated example. For example, when viewed in the direction of the longitudinal axis L, the blow-out nozzles 45, 45' can be arranged between the rotation axis D of the guide roller and the film tube 1.

[0090] Unlike the nozzle section of the second guide layer E2, the nozzle section 23' of the first guide layer E1 has only one blow-out nozzle 45, which is aligned along the traction direction A. The nozzle section 23'' of the third guide layer E3 has only one blow-out nozzle 45', which is aligned in the opposite direction to the traction direction A.

[0091] Therefore, the nozzle segment 23 of the middle second guide layer E2 blows both upward and downward, or both along and against the traction direction A. On the other hand, the nozzle segment 23' of the first guide layer 1 discharges upward only along the traction direction A, while the nozzle segment 23'' of the third guide layer E3 discharges downward only in the direction opposite to the traction direction A.

[0092] Figure 6 It shows according to Figure 3 A schematic side view of a second embodiment of the adjustment section 49, wherein, according to... Figure 1 The components corresponding to the components of the first embodiment have the same reference numerals and are described therein.

[0093] Unlike the first embodiment, the second embodiment of the adjustment section 49 has two guide layers E1 and E2. The guide sections 21 of these two guide layers E1 and E2 are identical and correspond to those guide sections of the second layer (horizontal) in the first embodiment. Therefore, both nozzle sections 23 can blow upwards and downwards, or blow in the traction direction A and against the traction direction A.

[0094] Figure 7A schematic side view of a third embodiment of the adjustment section 49 is shown, wherein components corresponding to those in the first two embodiments have the same reference numerals and are described therein.

[0095] Similar to the second embodiment, the third embodiment of the adjusting section 49 also has two guide layers E1, E2. The guide sections 21' of these two guide layers E1 and E2 are identical and correspond to those guide sections of the first layer (horizontal) in the first embodiment. Therefore, both nozzle sections 23 blow upwards along the traction direction A. It is also conceivable that the two guide elements are designed in the same way as the guide elements of the third layer (horizontal) in the first embodiment, and thus blow downwards in the direction opposite to the traction direction A.

[0096] Figure 8 A schematic side view of a fourth embodiment of the adjustment section 49 is shown, wherein components corresponding to those in the first three embodiments have the same reference numerals and are described therein.

[0097] Similar to the second embodiment, the fourth embodiment of the adjustment section 49 also has two guide layers E1 and E2. The guide section 21' of the first guide layer E1 is designed to be the same as the guide section of the first layer (horizontal) in the first embodiment, and therefore blows upward along the traction direction A. The guide section 21'' of the second guide layer E2 is designed to be the same as the guide section of the third layer (horizontal) in the first embodiment, and therefore blows downward in the opposite direction to the traction direction A.

[0098] List of reference numerals in the attached diagram:

[0099] 1 membrane tube 2 machine base 3 Extruder 4 Feed hopper 5 Feed hopper 6 blow molding head 7 Annular nozzle 8 Flattening unit 9 Traction unit 10 Cooling gas ring 11 Gas supply pipeline 12 blower 13 outlet nozzle 14 Frost line 15 Internal cooling tower 16 Gas extraction tube 17 Calibration basket 18 Calibration element 19 The central opening of the cooling gas ring 20 Temperature control device 21、21’、21’’ Guide Section 22 Guide rollers 23、23’、23’’ Nozzle section 24 blower 25 feed line 26 Air distribution ring 27 supply pipeline 28 air cooler 29 air heater 30 Tower frame 31 Control Unit 32 Temperature sensor 33 pressure sensor 34 Temperature sensor 35 Temperature sensor 36 frame 37 Adjustment unit 38 pivot arm 39 bracket 40 Connecting rod 41 Cam follower 42 Guide 43 plate 44 Fixed plate 45, 45‘ Blowout nozzle 46 bearing plate 47 connector 48 Connection part 49 Adjustment section

[0100] A Traction direction D axis of rotation E1 First guiding layer E2 Second guiding layer E3 Third Guiding Layer F diameter of the guide opening h Guide roller height H Maximum height of nozzle section K Calibration opening diameter L Longitudinal axis

Claims

1. Temperature control device (20) for temperature control of the film tube (1) extruded along the traction direction (A) above the frosting line (14): Multiple guide sections (21, 21', 21'') are distributed around a longitudinal axis (L) parallel to the traction direction (A) of the membrane tube (1) and form a central guide opening for guiding the membrane tube (1) along the longitudinal axis (L), wherein, The guide sections (21, 21', 21'') can be adjusted laterally relative to the longitudinal axis (L) to adjust the diameter (F) of the guide opening; Each of the guide sections (21, 21', 21'') has a guide roller (22), wherein the guide roller (22) is adjustable together with the guide section (21, 21', 21'') to guide the extruded film tube (1), and The nozzle sections (23, 23', 23'') associated with the guide roller (22), which are adjustable together with the guide sections (21, 21', 21''), wherein the nozzle sections (23, 23', 23'') have blowout nozzles (45, 45') designed to blow out temperature-controlled gas in a direction toward the longitudinal axis (L), Its features are, The nozzle segments (23, 23', 23'') are arranged relative to the longitudinal axis (L) to at least partially overlap the guide roller (22) radially.

2. The temperature control device (20) according to claim 1. Its features are, The nozzle segments (23, 23', 23'') are arranged at least partially radially outside the guide roller (22) relative to the longitudinal axis (L).

3. The temperature control device (20) according to claim 1. Its features are, The nozzle segments (23, 23', 23'') have a maximum height (H) in the longitudinal axis (L) direction that exceeds the entire length of the blow-out nozzle (45, 45'), the maximum height being at least 50% or at least 25% of the length of the blow-out nozzle, and the maximum height being at most 2.0 times, 1.5 times, 1.25 times or 1.0 times the height (h) of the guide roller (22).

4. The temperature control device (20) according to claim 1. Its features are, The guide rollers (22) of adjacent guide sections (21, 21', 21'') are arranged to be offset from each other in height along the longitudinal axis (L), and the guide rollers (22) at least partially intersect each other along the longitudinal axis (L) at least when the guide opening (F) is smaller than a predetermined diameter.

5. The temperature control device (20) according to claim 4. Its features are, The nozzle segments (23, 23', 23'') of the intersecting guide sections (21, 21', 21'') have a maximum height (H) at least above the area where the guide sections (21, 21', 21'') intersect along the longitudinal axis (L), the maximum height being at most 2.0 times, 1.5 times, 1.25 times or 1.0 times the height (h) of the corresponding guide roller (22).

6. The temperature control device (20) according to claim 1. Its features are, The blow-out nozzle (45, 45') is configured such that the temperature-controlled gas has at least one flow vector along the traction direction (A) and / or against the traction direction (A), the flow vector forming an angle of less than 90°, less than 60° or less than 45° with respect to the longitudinal axis (L).

7. The temperature control device (20) according to claim 1. Its features are, The nozzle section (23, 23', 23'') has multiple blow-out nozzles (45, 45').

8. The temperature control device (20) according to claim 1. Its features are, Each of the nozzle segments (23, 23', 23'') is an integral part of the corresponding guide segment (21, 21', 21'').

9. The temperature control device (20) according to claim 1. Its features are, Each guide section (21, 21', 21'') has multiple guide rollers (22).

10. The temperature control device (20) according to claim 9. Its features are, A common nozzle section (23, 23', 23'') is assigned to multiple guide rollers (22) of the guide section (21, 21', 21'').

11. The temperature control device (20) according to claim 1. Its features are, The temperature control device (20) has a cooling unit (28) for cooling the temperature control gas and / or a heating unit (29) for heating the temperature control gas.

12. The temperature control device (20) according to claim 1. Its features are, The temperature control device (20) has at least two guide layers (E1, E2, E3) of the guide section (21, 21', 21''), the guide layers being arranged one above the other along the direction of the longitudinal axis (L) and distributed around the longitudinal axis (L).

13. The temperature control device (20) according to claim 12. Its features are, At least two guide sections (21, 21', 21'') are always arranged one above the other along the longitudinal axis (L) and distributed on the periphery.

14. The temperature control device (20) according to claim 1. Its features are, The temperature control device (20) includes an adjustment unit (37) by means of which the guide sections (21, 21', 21'') can be adjusted laterally relative to the longitudinal axis (L) so that the corresponding guide rollers (22) move centrally relative to the longitudinal axis (L).

15. A blown film production line, comprising: Blow molding head (6), the blow molding head being used to eject a thin film tube (1) of plasticized thermoplastic material along the longitudinal axis (L) in the traction direction (A), and A cooling gas ring (10) is located downstream of the blow molding head (6) along the traction direction (A), forming a central opening through which the plasticized film tube (1) passes, and having at least one internal outlet nozzle (13) for blowing the cooling gas onto the film tube (1), causing the film tube (1) to change from a plastic state to a solidified state at the frost line (14). Its features are, The temperature control device (20) according to claim 1 is arranged downstream of the frost line (14).

16. The blown film production line according to claim 15, Its features are, A calibration basket (17) is arranged downstream of the cooling gas ring (10) and has a plurality of calibration elements (18) configured to enclose the thin film tube (1) and form a calibration opening for guiding the thin film tube (1). The calibration elements (18) are adjustable to set the diameter (K) of the calibration opening. The temperature control device (20) is located downstream of the calibration basket (17) and is installed in the calibration basket (17) or arranged at a distance from its axial direction.

17. The blown film production line according to claim 15, Its features are, The blown film production line includes a flattening unit (8) located downstream of the temperature control device (20) for flattening the film tube (1), and There are no components in the area between the temperature control device (20) and the flattening unit (8) that affect the film tube (1).

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