Extrusion head
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-16
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026051012_13082026_PF_FP_ABST
Abstract
Description
[0001] Rommelag Engineering GmbH
[0002] Talstraße 22-30, 74429 Sulzbach-Laufen, Germany
[0003] Extrusion head
[0004] The invention relates to an extrusion head for producing tubes as preforms for containers to be formed from plasticized plastic material, in particular intended for use in forming, filling and closing machines, comprising at least individual head parts which define a circumferential annular gap between them, which opens to the outside for the discharge of the plastic tube and which includes, at least in the discharge area, a guide device having a plurality of individual chambers open at both ends, each of which can be traversed by at least one identifiable filling device, such as a tubular filling mandrel.
[0005] DE 102008028 754 A1 discloses a device for manufacturing and filling containers, in which at least one tube of plasticized plastic material can be extruded into an open mold, wherein, by means of a filling device having several separate functional channels, at least the filling material can be introduced into the respective containers by means of a filling mandrel assigned to a particular mold, wherein a mandrel shielding hood is provided which has at least one functional chamber and which, in its functional position, establishes a media-carrying connection between its respective functional chamber and the respective assignable functional channel of the filling device. This makes it possible to introduce, via a respective functional channel of the filling device, those media into the functional chamber(s) within the shielding hood which are required for cleaning, sterilization, cooling / drying, etc.to bring the device into an aseptic state for starting a production period.
[0006] DE 102020004 564 A1 discloses a device and method for manufacturing plastic containers using a forming, filling and closing process, comprising at least a forming device with individual forming tools that can be repeatedly moved relative to each other from an open receiving position to a forming closed position, and an extrusion unit by means of which at least one extruded plastic tube can be inserted into the open receiving position of the forming tools, wherein the extrusion unit can be moved in the opposite direction to the forming device, which is fixed in position in every position of the forming tools, by means of a moving device with each extruded plastic tube.In this way, with continuous extrusion of the plastic tube by means of the extrusion unit, the actual shaping can be carried out in a stationary manner using the forming tool, which simplifies the design of the device as a whole, since the forming tool does not have to be moved back and forth kinematically in the extrusion direction of the plastic tube in a complex manner.
[0007] EP 3 684695 B1 discloses a device for manufacturing and filling containers, in which at least one tube of plasticized plastic material, coming from an extrusion head, can be extruded into an open mold, wherein at least the filling material can be introduced into the respective container by means of a filling device using filling mandrels which, at least during operation, extend through the extrusion head along at least one series of passages, wherein the extrusion head has a cuboid shell and wherein the height of the extrusion head, viewed parallel to the orientation of the respective filling mandrel, is less than the length of the extrusion head along the respective series of passages.The cuboid shell consists of at least one lower and one upper head or shell part, at least one of which has a channel guide for the plasticized plastic material. This channel guide includes an annular space in the center of which a receiving rib is arranged, featuring individual longitudinal recesses in the form of openings for the passage of the respective filling mandrels. The design of the extrusion head as a flat shell allows for a corresponding reduction in the height of the base frame surrounding the extrusion head, which forms the basis for the assembly of the device units above it. This results in a significant reduction in the overall height of the known device and a correspondingly reduced requirement for installation space.
[0008] During the filling process into individual container products, including ampoules, a particular challenge arises when the product is heat-sensitive, such as protein-containing solutions. This is described in detail in the publication by Wei Lu, Scott Faulhaber, Samir U. Sane, and Philippe Lam, "Biopharmaceutical Manufacturing Using Blow-Fill-Seal Technology," BioPharm International, January 7, 2011, Volume 24, Issue 7.
[0009] To effectively address this particular challenge, EP 3 157816 B1 discloses a method and apparatus for blow-fill-seal packaging of a heat-sensitive product that is subject to denaturation and / or precipitation if the product gets too hot, and proposes the following measures to counteract this:
[0010] Forming a container to obtain a container, - after forming the container, cooling to a container temperature between 60°C and 80°C, wherein the cooling step consists of waiting 2 to 5 seconds from the time of forming the container, - filling the formed container with the heat-sensitive product after the cooling step, wherein the product used in the filling phase has a temperature between about 0°C and about 20°C and has a temperature of a maximum of 40°C immediately after filling the formed container, and
[0011] - Closing the container.
[0012] Accordingly, after blow molding and before filling, the respective container is cooled in a chilled mold for a certain period of several seconds in order to reduce the heat input into the contents, which, with regard to the waiting time, can reduce the production output (number of containers to be produced per hour).
[0013] If the respective filling material is cooled significantly via a heat exchanger and filled into the container product at a very low temperature, this inevitably leads to the filling mandrels of the filling device being subjected to equally strong cooling and, consequently, also indirectly to the plastic tube discharged via a typical ring or inner die of the extrusion head adjacent to the filling device during extrusion, which can ultimately lead to uneven tube extrusion and, in the worst case, to production disruptions.
[0014] To address these disadvantages, WO 2023 / 102256 A1 proposes a method and device for dynamic cooling, which, with two different cooling stages, contributes to reducing the filling temperature for vaccines, thus enabling a gentle cooling process without impairing the dispensing of the plastic tubing. However, this again entails increased equipment complexity. 40grr / 132001 / WO
[0015] 5
[0016] Based on this prior art, the invention aims to provide an extrusion head for producing tubes as preforms for containers to be formed from plasticized plastic material, particularly for use in mold, fill, and seal (FFS) machines, which allows for improved temperature control during the actual manufacturing process while avoiding the described disadvantages. An extrusion head with the features of claim 1 as a whole achieves this objective.
[0017] According to the characterizing part of claim 1, at least one insulating device is provided as part of the guiding device, which at least partially forms the chambers and can be traversed by the respective filling or mandrel device in the same way as the other guiding device. This means that the filling mandrels are at least partially received and guided in chambers of the insulating device, so that the mandrels and thus the filling material can only absorb a negligible amount of heat from the heated extrusion head and the extruded warm plastic tube. This can be particularly important if the filling material is cooled to a significant degree, which is regularly the case if the filling material consists of heat-sensitive substances, such as protein-containing vaccines, which must be protected from excessive heat during the filling process.In any case, the insulation device significantly reduces the heat flow from the hot plastic tube and extrusion head to the guide device and the filling material.
[0018] In a preferred embodiment of the extrusion head according to the invention, the insulating device comprises a strip-shaped base body with one or more insertion strips, which is inserted into the extrusion head on the discharge side of the plastic tube. It is further preferred that the insertion strips consist at least partially of a high-temperature resistant plastic material with low thermal conductivity and a low coefficient of thermal expansion, preferably polyetheretherketone (PEEK). The filling mandrels of the filling device are surrounded by the insulating insert in such a way that the heat flow from the heated extrusion head and the extruded tube in the circumferential annular gap to the filling mandrels is significantly reduced.This thermal insulation minimizes both the cooling of the inner nozzle or annular gap and thus of the plastic tube within it, and the heating of the filling mandrels and their potentially heat-sensitive contents. Besides energy savings during operation, this also allows for a more stable production process for the preforms, from which the final container products are formed in a mold on the exit side of the extrusion head.
[0019] In the aforementioned sense, it has proven particularly thermally advantageous for the process if the insulating device, viewed in the direction of travel of the filling mandrels of the mandrel assembly, is arranged at a predetermined distance and parallel to the annular gap, and has a height that corresponds at least partially to the length of the annular gap on the discharge side, arranged parallel to it. In a further preferred embodiment of the extrusion head according to the invention, the base body is formed in one piece or in multiple parts in the form of a frame and preferably made of a metallic material, into the respective recess of which an insertion strip can be inserted.Preferably, it is further provided that the respective insert strip is arranged in a row, one behind the other, and has access openings of the same diameter that can be aligned with corresponding through-openings in the frame, which are arranged coaxially to the access openings, at least during operation. In this way, a multi-part plastic insert, preferably in the form of individual plastic strips, is received in a U-shaped metallic frame.
[0020] 7
[0021] that this stable frame can safely absorb and dissipate the pressure forces arising during operation, whereas the strip-shaped insulating bodies made of insulating material are protected from deformation and other mechanical impairment in the form of the respective insert strip.
[0022] In a further preferred embodiment of the extrusion head according to the invention, the insulating chambers of the insulating device are divided into groups, preferably maintaining a predetermined distance from one another. Preferably, the group division into rows and columns is arranged parallel to or perpendicular to the recess in the frame. This results in a structured design for the insulating device as a whole, which can be adapted well to a predetermined number of filling tubes of the filling device and can be implemented stably, a number that can vary depending on the configuration of the BFS machine.
[0023] In a further preferred embodiment of the extrusion head according to the invention, the two outermost chambers of the insulating device are kept free of insulation. In this way, reliable insulation is provided, particularly for the centrally positioned filling mandrels of the filling device, whereas this is not strictly necessary for the two outermost chambers, which can instead be designed as metallic chambers for further stiffening of the overall system.
[0024] In a further particularly preferred embodiment, the base body has a flange-like widening towards the outside on the side facing the discharge side, which serves as a passage for at least one fixing means, such as a fixing screw, for the purpose of 40grr / 132001 MO
[0025] 8
[0026] The base body is fixed to an adjacent head section. In this way, the base body can be interchangeably fixed to the extrusion head, which simplifies assembly, maintenance, and replacement.
[0027] The extrusion head according to the invention will now be explained in more detail with reference to various exemplary embodiments shown in the drawing. The drawings are presented in a general and not to-scale representation.
[0028] Figure 1 shows a cross-section through a first embodiment of the extrusion head;
[0029] Figure 2 shows a perspective view of a longitudinal section through the extrusion head according to Figure 1;
[0030] Figure 3 in perspective view shows a longitudinal section through a base frame for receiving a one-piece insulating body in the form of an insert, as used in Figures 1 and 2; Figure 4 in perspective top view shows a cuboid insert made of insulating material for use in the frame according to Figure 3;
[0031] Figure 5 shows a partial lower side view according to Figure 2 with the base frame according to Figure 3 and the insert in a functional position according to Figure 4;
[0032] Figure 6 shows a longitudinal section comparable to Figure 2 for a further embodiment of a flat extrusion head; and
[0033] Figures 7 to 9 again show, in perspective side view, another insulating device consisting of a further base frame, as shown in Figure 8, and inserted insert strips as insulating parts, one of which is shown in Figure 9. The extrusion head shown by way of example in Figures 1 and 2, which is also referred to in technical terms as a tube head, is positioned upstream in the vertical production direction, viewed from top to bottom, of a device for producing container products to be formed, such as ampoules or bottles (not shown), from plasticized plastic material. This forming device has individual mold parts 12 extending along a common vertical production line 10, which can be moved towards and away from each other in pairs in order to close or open a common production mold 14.to open, in which the respective container product is formed, which is subsequently filled with material by means of a filling device 16 and then hermetically sealed via a head part. The containers, moving along the production line 10, emerge filled and hermetically sealed at the underside of the forming device in the form of a container chain for further use. For this manufacturing function, the individual forming parts 12, which interact in pairs, are moved by means of a self-contained forming chain 18, which is guided around the perimeter by individual deflection rollers 20. Such forming devices are known and are therefore only indicated in Figure 1 on their inlet side, insofar as this is relevant for explaining the function and structure of the extrusion head.A forming device of this kind with individual forming parts which are guided in pairs along container or forming chains, interacting together, is exemplified by DE 102008006073 A1.
[0034] This forming device or similarly constructed forming devices (not shown) includes the extrusion head, which serves to produce hoses as preforms for the container products to be subsequently formed from plasticized plastic material, in particular for use in a forming, filling and closing machine, such as the one shown in 40grr / 132001 MO.
[0035] 10
[0036] as partially shown in Figure 1. The extrusion head consists of individual components and has at least two head parts 22, 24, which define a circumferential annular gap 26 between them. This gap or nozzle outlet 28 on the underside 30 of the extrusion head allows the plasticized plastic tube to exit into the open air. The head part 24 is also referred to as the inner nozzle. As shown particularly in Figure 2, the nozzle-like annular gap 26 includes, at least in the area of the plastic tube discharge, a guide device 32. This guide device has a plurality of individual chambers 34, open at both ends, which each chamber, forming a guide, can be traversed by at least one associated filling device 16, such as a tubular filling mandrel 36 or filling tube.For the sake of simplicity, Figure 2 shows only a single filling mandrel 36 in the extended filling state as shown in Figure 1; however, it is understood that a separate filling mandrel 36 is provided for each chamber 32, in this case, therefore, twenty filling mandrels 36 for the same number of chambers 34, although this number may vary depending on the manufacturing machine. In the position of the filling device 16 shown in Figures 1 and 2, all filling tubes or filling mandrels 34 of the same design, as shown, also assume the same position, which corresponds to a discharge position for the filling material that is discharged onto the hollow container product formed from the preform before the container is closed.
[0037] In the following embodiment, five adjacent and parallel chambers 34 are grouped into a group 38, which is separated from the next group 38 by a rib-like partition 40. The wall thickness of this partition further stiffens the overall structure, making it particularly pressure-resistant. The chambers 34, open at both ends or end faces, together form a foot-side part of the guide device 32, which at least partially forms the guide for an associated filling device 16. In the filling position, the filling device extends from the top 44 of the extrusion head to its underside 30. All chambers 34 have the same or substantially the same inner diameters, adapted to the outer diameter of the respective filling mandrel 36, allowing the filling device 16 to pass through unimpeded.In this way, as described, twenty container products filled with contents can be produced in a row per manufacturing step, which are summarized in a kind of container card and subsequently separated from it, for example by means of punching, for later use.
[0038] As part of the aforementioned guide assembly 32, at least one insulating device 46 is provided, which at least partially forms the chambers 34 and can be traversed by the respective filling or mandrel device 16 in the same way as the rest of the guide assembly 32. The aforementioned nozzle-like annular gap 26 guides the plasticized plastic material from a central feed channel 48 arranged laterally on the extrusion head, which receives the plasticized plastic material in the usual manner from an extruder screw unit (not shown). This feed channel forms a jacket-like closed plastic tube, which is later inserted into the molding device and forms the respective container wall as well as the head-like closing part.The extruded plastic material is first introduced via the inlet channel 48 into a circumferential ring channel 50 with a rectangular cross-section and increased volume arranged within the extrusion head 10, before the plasticized plastic material is discharged from there, viewed from top to bottom in a vertical direction in the direction of Figures 1 and 2, via the nozzle outlet 28 on the underside 30 of the extrusion head, after passing through the annular gap 26 arranged between the ring channel 50 and the nozzle outlet 28.As can be further seen from Figure 1, the two annular gap sections 52 of the annular gap 26, which extend downwards from the annular channel 50 in the direction of view of Figure 1, are spaced further apart horizontally than the two further annular gap sections 54, which extend vertically and parallel to each other and open downwards towards the nozzle outlet 28. Between each pair of annular gap sections 52 and 54, there is a feed device 56 extending obliquely towards the nozzle outlet 28, which establishes the fluid connection between sections 52 and 54, thus ensuring a continuous flow of the plasticized material from the annular channel 50 to the nozzle outlet 28.Furthermore, below the inclined feed device 56 towards the two arc-shaped ends 57 of the annular gap 26, as shown in Figure 2, at least one adjusting device 58 is provided in pairs opposite each other, each with an externally operable engagement screw 60, by means of which the dispensed quantity of plasticized plastic material at the nozzle outlet 28 can be at least partially regulated. For this purpose, the adjusting device 58 with its associated engagement screw 60 engages in the lower region of the annular gap 26, which may also have a flow chamber 61 upstream of the nozzle outlet 28 that widens the gap diameter to equalize the flow of the plastic medium (see Figure 5).
[0039] As can be seen particularly from Figures 3 and 4, the insulating device 46 has a strip-shaped base body 62, which can be inserted into the plastic tube on its discharge side, i.e., viewed from the underside 30 of the extrusion head. The strip-shaped base body 62 has a frame 64 that provides a rectangular recess 66 for receiving a block-like insert or insertion strip 68, as shown by way of example in Figure 4. The recess 66, or rather the receiving surface defined by the frame 64, is bounded by two parallel strip bodies 70, 72, which are kept at a distance from each other by cross ribs 74 of the same construction. These cross ribs 74 are an integral part of the lower strip body 72 and have two chambers 34 arranged on each side at their outermost points, which are kept clear by an insulating element.The two outermost chambers 34, as well as the two strip bodies 70, 72, are made of a metal material. Extending from the two vertically oriented crossbars 74, two flange-like extensions 76 are provided on the edge and bottom, each with openings for the insertion of a fixing element, such as a fixing screw 78. In this way, the base body 62 as a whole can be interchangeably fixed to the underside 30 of the extrusion head, and the insulating insertion strip 68 can be separated from the frame 64 as needed, for example for cleaning, once the base body 62 is removed from the corresponding receptacle 80 in the extrusion head, which is at least partially bounded by the head section 24.
[0040] As shown in particular in Figure 5, the insulating device 46, viewed in the direction of travel of the filling mandrels 36 of the filling device 16, is arranged at a predetermined distance and parallel to the annular gap 26, and has a height that corresponds at least to the length of the annular gap 26 on the dispensing side when arranged parallel to it. The height of the cross webs 74 (see Figure 3) of the frame 64 corresponds essentially to the height of the lower further annular gap sections 54.This is precisely the thermally critical area where the annular gap 26 is closed towards the filling device 16 with its tubular filling mandrels 36, where the lower annular channel sections 54 are closer to the filling device 16 than the upper annular gap sections 52, which are further apart via the conical feed device 56. This is particularly important when the filling device 16 is in its material-dispensing position as shown in Figures 1 and 2. In this case, thermal decoupling of the cold material in the filling device 6 and the warm or hot plasticized material in the annular gap 26 near the nozzle outlet 28 is highly advantageous.
[0041] As shown in Figure 3, the through-openings 82 of both strips 70, 72 have the same or substantially the same free inner diameter and are arranged coaxially in pairs. Furthermore, the respective strips 70, 72 accommodate, between their respective through-openings 82, which are arranged in opposing groups, reinforced partition wall sections 84 (Figure 5), which are also vertically aligned with each other. The wall thickness of these partition wall sections 84 for both strips 70, 72 corresponds essentially to the wall thickness of each partition wall 40 of the block-like insert strip 68.The insulating body shown in Figure 4 has access openings 86 of comparable diameter, which, during operation of the extrusion head, preferably align coaxially with the adjacent through-openings 82 of both strips 70, 72. Before commissioning, however, a certain lateral offset may exist, as shown in Figure 5. This offset is only eliminated by mechanical and / or thermal stress during operation, resulting in the access openings 86 and through-openings 82 being perfectly aligned. This contributes to compensating for any tolerances and also increases the overall stiffness of the system in this area. Figures 4 and 5 also show that the insulating insert strip 68 has a shorter installation length, since the two outermost chambers 34 are not part of the insulating device 46.Thus, the strip according to Figure 4 shows only four fully extending through-holes 86 at its edges, whereas the two middle groups 38 are each provided with five chambers 34 and with five through-holes 86 and are also spaced accordingly to the two outer groups of four via the stiffening intermediate walls 40.
[0042] As can be further seen from Figure 4, the insertion strip 68 can also have so-called support air bores 88, which can be aligned with support air bores 88 in the strips 70, 72 (only partially shown) in order to achieve a support air supply into the interior of the molded tube during the tube forming process. Furthermore, centering elements 90 can be provided both on the insertion strip 68 and in the frame 64 to ensure precise positioning of the insertion strip 68 relative to the frame receptacle for the base body 62, as shown in Figures 7 to 9.
[0043] For the insert or insertion strip 68, polymers with low thermal conductivity and a low coefficient of thermal expansion are advantageously used; the latter simplifies the overall design, which must accommodate an operating temperature range of approximately 20°C to 250°C for the extrusion head components. To further reduce thermal expansion, fiber- and / or particle-reinforced polymers can also be used, for example, PEEK with 30% carbon or glass fiber content (available under the trade names TECAPEEK CF30 and Ketron GF30, respectively). These materials exhibit a linear coefficient of thermal expansion of less than 4 x 10⁻⁶ in the range of 23°C to 150°C. -5 / K on.
[0044] The insert or slide-in strip 68 is further preferably and at least partially made of a material with a thermal conductivity at 25°C according to DIN 52612-1 of less than 0.5 W / (m·K), preferably less than 0.4 W / (m·K). The insert or slide-in strip 68 is further preferably and at least partially made of a material with a high modulus of elasticity according to ISO 527 (also known as Young's modulus) of more than 2.5 GPa, preferably more than 3 GPa.
[0045] The insert or insertion strip 68, particularly in the manufacture of containers for medical purposes, is preferably and at least partially made of a material with proven suitability for contact with food (also referred to as "food conformity"), as regulated for the EU in EU Regulations 1935 / 2004, 10 / 2011 and 2023 / 1442 or for the USA by the Food and Drug Administration (FDA) Food Contact Substance Notification Program (FCN).
[0046] The insertion strip 68 can furthermore consist at least partially of a plastic with a continuous operating temperature of more than 150°, and preferably consists of - hereinafter referred to as according to DIN EN ISO 1043-1 - PEEK, PEK, PPS, PSU, PES, PPSU, PAI, a fluoropolymer or a liquid crystal polymer (LCP).
[0047] The linear thermal expansion coefficient of the plastic for the insert or slide-in strip 68 according to DIN53752 is generally less than 7 x 10' 5 / K, preferably less than 6 x 10' 5 / K, especially preferred 4 x 10' 5 / K or less. Furthermore, for the thermal decoupling of the produced plastic tube from the filling device 16, it has proven advantageous if the engagement gap between the through-openings 86 of the insertion strip 68 and the outer circumference of the respective tubular filling tube 36 of the filling device 16 can be predetermined and preferably has a value of 0.5 mm within the guide.
[0048] Starting from the first embodiment according to Figures 1 to 5, a further embodiment is presented in Figures 6 to 9; however, only insofar as it differs substantially from the preceding 40grr / 132001 MO
[0049] 17
[0050] The embodiment differs. In this embodiment, the same components are also provided with the same reference numerals, and the explanations given so far also apply to the further embodiment.
[0051] Figure 6 shows a further embodiment of the extrusion head in longitudinal section. This embodiment is now significantly flatter than the first embodiment, and the plastic melt is again fed from an extruder screw assembly (not shown) via a feed channel 48, which this time is located on the top surface 44 of the extrusion head. Key differences compared to the first embodiment are that the annular gap 26 now extends vertically downwards from the annular channel 50 towards the die outlet 28. Furthermore, the annular channel 50 is at least partially bounded by an upper head section 24 and a lower head section 22, which is connected to the feed channel 48 for the plasticized material via a feeder 92 between sections 22 and 24.
[0052] Further significant differences exist in the construction of the insulating device 46, as shown in Figures 7 to 9. In this respect, the strip-shaped base body 62 according to Figure 7 has a frame 64 according to Figure 8, which, in addition to an upper strip body 70 and a lower strip body 72, also has two intermediate strips 94. All strips have the same vertical distance to each adjacent strip, each forming a corresponding recess 66 for receiving an insert or slide-in strip 68, as exemplified in Figure 9. Thus, a strip-shaped base body 62 is formed in the assembled state according to Figure 7, and this construction is particularly thermally and mechanically stable.While the insert or slide-in strip 68 according to Figure 9 is again made of a suitably appropriate plastic insulating material, the frame 64 can again be constructed of metallic materials. In contrast to the first-mentioned frame solution, in the frame construction according to Figure 8, the upper strip body 70 and the two intermediate strips 94 are integral components of a U-shaped upper frame part 96, which is firmly connected, in particular screwed, to a lower, essentially flat frame part. The two intermediate strips 94 also have through-openings 82, which are coaxially aligned with the adjacent through-openings 82 of the upper and lower strip bodies 70 and 72, respectively.For the sake of simplicity, not all openings are designated with reference numeral 82, nor are the respective through-openings 86 within the insertion strip 68, which are aligned with the corresponding through-openings 82 at least during operation of the extrusion head. It is understood that, even in the solution according to Figures 6 to 9, support air bores 88 (not shown) may be present, and again centering elements 90 are used to fix the respective insertion strip 68 in the clamped frame 64. In this arrangement, groups 38 of chambers 34 are formed, which extend not only horizontally in the row direction but also vertically in the column direction. In this respect, the rows run parallel to the respective recess 66 in the frame 64, and the columns run perpendicular to it.In the present embodiment, the two outermost chambers 34 of the insulating device 46 are again kept free of insulation.
[0053] With the solution according to the invention, the respective insulating device 46 largely minimizes both the cooling of the inner nozzle in the form of the annular gap 26 and thus of the adjacent plastic hose, and the heating of the filling mandrels 36 of the filling device 16. It has been shown that, in addition to energy savings and the protection of the product from overheating, this also results in improved performance when operating with the 40grr / 132001 MO
[0054] 19
[0055] The extrusion head leads to more stable production processes in container manufacturing. The illustrated construction of a frame 64 with its associated insert or slide-in strip 68 creates a mechanically robust, and in particular pressure-resistant, insulating device 46 within the extrusion operation with the extrusion head. This has no equivalent in the prior art.
Claims
Patent claims 1. Extrusion head for producing tubes as preforms for containers to be formed from plasticized plastic material, in particular intended for use in forming, filling and closing machines, comprising at least individual head parts (22, 24) which define between them a circumferential annular gap (26) which opens to the outside for the discharge of the plastic tube and which includes at least in the discharge area a guide device (32) which has at least one chamber (34) open at both ends, each of which can be traversed by at least one assignable filling device (16), such as a tubular filling mandrel (36), characterized in that at least one insulating device (46) is provided as part of the guide device (32), which at least partially forms the chambers (34) and can be traversed by the respective filling device (16) in the same way as the other guide device (32).
2. Extrusion head according to claim 1, characterized in that the insulating device (46) has a strip-shaped base body (62) which is inserted into the extrusion head on the discharge side of the plastic tube.
3. Extrusion head according to claim 1 or 2, characterized in that at least one insertion strip (68) in the base body (62) consists at least partially of a plastic material with low thermal conductivity, a high modulus of elasticity, and a low coefficient of thermal expansion with demonstrable food-grade conformity, preferably polyetheretherketone (PEEK).
4. Extrusion head according to any one of the preceding claims, characterized in that the insulating device (46), viewed in the direction of travel of the filling mandrels (36) of the filling device (16), is arranged at a predetermined distance and parallel to the annular gap (26) and has a height that corresponds at least partially to the length of the annular gap (26) on the discharge side, arranged parallel to it.
5. Extrusion head according to one of the preceding claims, characterized in that the base body (62) is formed in one piece or in multiple parts in the form of a frame (64), into the respective recess (66) of which an insertion strip (68) can be assigned.
6. Extrusion head according to one of the preceding claims, characterized in that the respective insertion strip (68) has through-openings (86) of the same diameter for the chambers (34) arranged in a row one behind the other, which can be brought into alignment with corresponding through-openings (82) in the frame (64), which are arranged coaxially to the through-openings (86) at least during operation.
7. Extrusion head according to one of the preceding claims, characterized in that the insulating chambers (34) of the insulating device (46) are divided into groups (38) which preferably maintain a predetermined distance from each other.
8. Extrusion head according to one of the preceding claims, characterized in that the group division of the groups (38) into rows and columns is carried out parallel along the recess (66) in the frame or transversely thereto.
9. Extrusion head according to one of the preceding claims, characterized in that the two outermost chambers (34) of the insulating device (46) are kept free of insulation.
10. Extrusion head according to one of the preceding claims, characterized in that the base body (62) has a flange-like widening (76) towards the outside in the direction of the discharge side, which serves for the passage of at least one fixing means, such as a fixing screw, for fixing the base body (62) to an adjacently arranged head part (24).