Installable extruder head for extruder

Abstract

The invention relates to an installable extruder head (1) for an extruder (100), said extruder head being designed to be arranged downstream of a screw cylinder (101) in an axial extrusion direction, comprising: - a tool mounting (2) with a cavity (3) for at least one extrusion tool (4); - at least one extrusion tool (4) which is provided with at least one tool extrusion channel (5) that can be attached to the screw cylinder (101) for conveying purposes in order to form an extruded profile and with an outer channel opening (7) for dispensing the extruded profile, wherein the tool mounting (2) has a base part (14) which surrounds the cavity (3) and a cover (15) for closing the cavity (3); the extrusion tool (4) is designed in the form of a cartridge, and the cavity (3) of the tool mounting (2) is designed in the form of a cartridge receiving area such that the extrusion tool (4) can be inserted into the cavity (3) opposite the axial extrusion direction; the extrusion tool (4) has a respective stop (11, 11') in the axial extrusion direction and opposite the axial extrusion direction, said stops being used to allow the extrusion tool (4) to be secured by clamping same against the tool mounting (2) by means of a pressure exerted by the cover (15); and the extrusion tool (4) has a main part (8), a first protrusion (9) which protrudes from the main part (8) in the axial extrusion direction, and a second protrusion (9') which protrudes from the main part (8) opposite the axial extrusion direction. Each of the protrusions (9, 9') can be brought into engagement with a protrusion receiving area (13, 13') of the tool mounting (2), said protrusion receiving area being designed to provide a correct fit, each of the protrusions (9, 9') has a smaller dimension in the radial direction than the main part (8), and each of the protrusions (9, 9') contains a region of the at least one tool extrusion channel (5).

Description

[0001] Mountable extruder head for extruder

[0002] The present invention lies in the technical field of producing extruded profile parts and relates to a mountable extruder head for an extruder. The invention further extends to an extruder with an extruder head according to the invention, as well as the use thereof.

[0003] Insulated glazing units consist of two or more panes of glass or polymeric materials. Insulated glazing units consist of a circumferential spacer attached between two adjacent panes, creating a gas- or air-filled cavity between the panes that provides the insulating properties of the insulating glazing. The thermal insulation capacity of insulating glazing units is therefore significantly higher than that of single-pane glazing. Insulated glazing units are commercially available in large quantities and frequently used, so their basic structure is familiar to those skilled in the art. They have also been described numerous times in patent literature, with reference to WO 2019 / 201530 A1 being cited as an example.

[0004] The thermal insulation properties of insulating glazing are significantly influenced by the thermal conductivity in the edge seal area, with the spacer playing a particularly important role here. With metallic spacers, the high thermal conductivity of the metal leads to the formation of a thermal bridge at the edge of the insulating glazing. This thermal bridge leads, on the one hand, to heat loss in the edge area of ​​the insulating glazing and, on the other hand, to the formation of condensation on the inner pane in the area of ​​the spacer in conditions of high humidity and low outside temperatures. To solve these problems, so-called "warm edge" systems are increasingly being used. These spacers are made of materials with lower thermal conductivity, particularly plastics.

[0005] Spacers for insulating glazing are often complexly shaped profile parts which, in industrial mass production, are manufactured from extruded profile strands. Those skilled in the art will be familiar with extrusion, a standard process engineering method used in many technical fields. Plastically deformable materials are continuously pressed out of an opening as a profile strand under pressure and, if necessary, heating. Extruders for the production of spacers for insulating glazing typically contain a screw cylinder in which the material, usually in the form of a powder or granulate, is homogenised and compressed at the same time by the axial rotation of a motor-driven screw in a (hollow) cylinder. The plastics used to manufacture spacers for insulating glazing are typically heated in the extruder, e.g. to a temperature of approx.200 °C, which causes the plastics to soften. A terminal extruder head with at least one integrated extrusion channel is arranged downstream of the screw barrel in the extrusion direction. The material conveyed from the screw barrel is shaped in the extrusion channel. Finally, a profile strand is discharged from an outer channel outlet of the extrusion channel, from which the profile parts can be obtained by cutting to length.

[0006] Due to the diverse construction of insulating glazing units, the spacers typically also require custom profile shapes. In particular, in addition to the profile shape, the width and height of a spacer depend on the dimensions of the insulating glazing unit, the desired cavity size, and the desired size of the cavity in the spacer, which typically houses the desiccant. Custom features may also be desired, such as co-extrusion from different plastics or the incorporation of glass fibers for mechanical reinforcement and improved stability of the spacers.

[0007] In practice, this requires relatively frequent replacement of the extruder heads mounted in the extruder, which is time-consuming and costly, as the assembly work always involves extended extruder downtimes. The same applies when extruder heads need to be replaced due to wear or defects. If extrusion is carried out at elevated temperatures, as is common with profile extrusions for plastic spacers for insulating glazing, an extruder head must first be heated to the desired extrusion temperature after assembly before it can be used. This also involves a certain amount of time loss.In addition, extruder heads are designed to be robust and made of strong materials due to the relatively high compressive forces that occur during extrusion. They typically weigh several tens of kg, and changing an extruder head is physically demanding if performed manually by a worker, as is usual. According to JP H10-58513 A, US 9770859 B2, JP 4325859 B2, and US 5817268 A, an extruder with an extruder head downstream in the feed direction can be removed, with the extrusion die being insertable into the extruder head.

[0008] In contrast, the object of the present invention is to create a way to produce various profile strands, particularly for the production of spacers for insulating glazing, in a cost- and time-efficient manner. In particular, the extruder should enable quick and easy changing of the extrusion die while simultaneously being mechanically stable. The production of various profile strands should be possible with relatively minimal adaptations to existing production facilities.

[0009] These and other objects are achieved according to the invention by a mountable extruder head for an extruder according to the independent patent claim. Advantageous embodiments of the invention are set forth in the subclaims.

[0010] According to the invention, a mountable extruder head for installation in an extruder is shown. Conventionally, the extruder comprises a screw barrel in which the material, e.g., in the form of a powder or granulate, is homogenized and compressed by the axial rotation of a motor-driven screw in a (hollow) cylinder.

[0011] The extruder head is designed to be mounted in an extruder such that the extruder head is arranged downstream of the screw barrel of the extruder in the axial extrusion direction (feed direction). Thus, the extruder head is arranged axially downstream of the screw barrel in the extrusion direction. The term "axial" refers to the axial direction of the axially rotatable screw of the screw barrel. Accordingly, "radial" refers to the perpendicular radial direction of the screw of the screw barrel. For the purposes of this description of the invention, the term "axial extrusion direction" refers to the axial direction of the screw barrel in the feed or extrusion direction of the screw barrel.

[0012] The extruder head is designed so that it can be mounted in the extruder (can be removed without destruction), whereby the extruder head is typically mounted end-on in the extruder in the extrusion direction. In the assembled state, the extruder head is a component of the extruder, but can be customized as a modular assembly compared to the rest of the extruder. The extruder head comprises a tool holder which has a cavity for at least one extrusion tool that can be inserted into the cavity. The tool holder serves to hold the at least one extrusion tool, which can be received and positioned in the cavity and fixed (fastened) to the tool holder. The extruder head can preferably be mounted in the extruder via the tool holder, whereby assembly preferably takes place exclusively via the tool holder. Therefore, the at least one extrusion tool does not serve to mount the extruder head in the extruder.

[0013] The extruder head further comprises at least one extrusion die, preferably precisely one extrusion die, wherein the extrusion die is provided with at least one extrusion channel for forming and discharging an extruded profile strand. For clarity, the at least one extrusion channel of the extrusion die is hereinafter referred to as the "die extrusion channel." The die extrusion channel has a terminal opening or outer channel mouth, which serves to discharge the profile strand from the extrusion die (i.e., to discharge the profile strand from the extruder head or extruder).

[0014] The at least one extrusion die can be inserted into the cavity of the die holder, wherein the extrusion die can be secured to the die holder or is secured in the inserted state. The at least one die extrusion channel is designed such that the material pressed through the die extrusion channel is provided with a desired profile shape in order to be discharged at the outer channel opening as a profile strand with a desired profile.

[0015] The extruder head is designed such that the at least one tool extrusion channel of the extrusion tool can be connected to the screw barrel for conveying purposes when the extrusion tool is inserted into the cavity and secured to the tool holder. When the extrusion tool is inserted into the cavity and secured to the tool holder, and when the extruder head is mounted in the extruder, the at least one tool extrusion channel is connected to the screw barrel for conveying purposes, i.e., material can be conveyed from the screw barrel into the at least one tool extrusion channel and discharged from the channel opening as a shaped profile strand.The at least one extrusion tool is designed in the form of a cassette for insertion into the cavity of the tool holder, and the cavity of the tool holder is correspondingly designed in the form of a cassette receptacle, so that the extrusion tool can be easily inserted into the cavity of the tool holder and secured to the tool holder. On the other hand, the insert part can be easily detached from the tool holder and removed from the cavity of the tool holder.

[0016] For the purposes of the present invention, the term "cassette" refers to a (one-piece) insert for insertion into the cavity of the tool holder, without necessarily requiring a specific external shape of the extrusion tool. In particular, an extrusion tool designed in the form of a cassette is not necessarily box-shaped or cuboid-shaped.

[0017] The cassette-shaped extrusion die and the corresponding cassette-shaped tool holder design enable simple and quick changing or replacing of the extrusion die (quick-change system), whereby the tool holder can advantageously remain mounted in the extruder during the die change. Thus, unlike conventional procedures, it is not necessary to disassemble or assemble the entire extruder head when changing or replacing the extrusion die. Instead, it is sufficient to simply remove the cassette-shaped extrusion die from the cavity of the die holder and insert a new, also cassette-shaped extrusion die into the cavity and secure it to the die holder.In addition to changing the extrusion die to produce profile strands with different profile shapes, extrusion dies can be easily and quickly replaced in the event of wear or failure. This is a major advantage of the extruder head according to the invention, which significantly simplifies the production of differently shaped profile strands for spacers for insulating glazing and enables the time- and cost-efficient production of spacers with different profiles.

[0018] A further advantage of the extruder head according to the invention is that only the extrusion die, which is designed as a cassette, is changed, so that the operator has to handle significantly lighter components during manual changes. A further advantage of the extruder head according to the invention is that the extrusion die can be preheated and brought to operating temperature before being inserted into the cavity of the die holder, allowing extrusion to continue quickly with a relatively short interruption. This also contributes to the time- and cost-efficient production of profile strands.

[0019] It is understood that the extrusion tool itself can be composed of several components. However, it is crucial that the extrusion tool is easy and quick to handle as a single component, allowing it to be easily inserted into the cavity of the tool holder, secured to the tool holder, released from the tool holder, and removed from the cavity of the tool holder again, enabling quick changes or replacement of extrusion tools.

[0020] The tool holder is designed such that the extrusion tool can be secured (preferably exclusively) to the tool holder by axial stops (arranged in and opposite to the axial extrusion direction). This enables particularly simple positioning and securing of the extrusion tool to the tool holder and offers further advantages, particularly in connection with the thermal expansion of the extrusion tool, which will be discussed in more detail below.

[0021] The tool holder is further designed so that the extrusion tool can be secured (preferably exclusively) by clamping or clamping the tool holder (at the axial stops). This advantageously enables particularly quick and easy securing of the extrusion tool in the tool holder.

[0022] The tool holder comprises a base part surrounding the cavity and a cover for closing the cavity to the outside. The extrusion tool can be secured to the tool holder by the cover mounted on the base part and the pressure exerted by the cover by means of a clamping action (clamping). This enables particularly simple and quick securing of the extrusion tool to the tool holder. Similarly, the extrusion tool can be easily and quickly detached from the tool holder by removing the housing cover in order to remove the extrusion tool from the cavity. This enables particularly time- and cost-efficient changing or replacement of the extrusion tool.

[0023] The extrusion tool has a base body, as well as a first projection in the axial extrusion direction (i.e. a section protruding from the base body in the axial extrusion direction) and a second projection opposite to the axial extrusion direction (i.e. a section protruding from the base body opposite to the axial extrusion direction), wherein the two projections can each be brought into engagement with or are in engagement with a projection receptacle of the tool holder, which projection is designed to fit snugly. This configuration enables particularly simple and reliable positioning of the extrusion tool in the cavity of the tool holder. The projections each have a smaller dimension in the radial direction (and preferably also in the axial direction) than the base body.The reduced dimensions of the projections in the radial direction result in preferred axial stops on the base body, which can be used to clamp the extrusion die in place. The extrusion die can thus be easily, reliably, and quickly positioned in the cavity of the die holder and secured to the die holder by clamping.

[0024] The said projections each contain a region of the at least one tool extrusion channel, wherein it is particularly advantageous if the (first) projection can or does engage in the extrusion direction through a projection receptacle designed in the form of an opening in the lid and has the outer channel opening for the extrusion profile to exit the extruder. This measure also enables a particularly simple design of the extruder head. On the one hand, the extrusion tool can be easily positioned reliably and securely in the cavity and secured to the tool holder. On the other hand, the extrusion tool can be easily connected to the screw cylinder in terms of conveying technology via the projecting sections or projections, wherein the profile strand emerging from the extrusion tool can be easily released through the projection engaging through the lid and fed for further processing.

[0025] In a further preferred embodiment of the invention, the tool holder is provided with a nozzle-shaped extrusion channel, which is hereinafter referred to as the "tool holder extrusion channel" for clear reference and differentiation from the tool extrusion channel. The tool holder extrusion channel has an opening or mouth for the conveyor connection to the screw cylinder, wherein the tool holder extrusion channel can also be conveyor-connected to the at least one tool extrusion channel of the extrusion tool or, when the extrusion tool is inserted in the cavity and secured to the tool holder, is connected to convey material to be extruded from the screw cylinder to the extrusion tool. This configuration enables a conveyor connection of the extruder head to the screw cylinder in a particularly simple manner.

[0026] Particularly preferably, the tool holder and the extrusion tool are designed such that the at least one tool extrusion channel automatically establishes a conveying connection with the tool holder extrusion channel when the extrusion tool is inserted into the cavity of the tool holder and secured to the tool holder. This feature enables a particularly simple and quick change or replacement of the extrusion tool and a particularly rapid continuation of the extrusion process after the tool change.

[0027] In a further preferred embodiment of the invention, the tool holder is provided with a first clamping flange for connection to a further or second clamping flange of the extruder, which enables simple and reliable assembly of the extrusion head in the extruder via two clamping flanges, which can advantageously be firmly connected to one another, for example by screws, and are well suited to absorb the relatively high compressive forces during extrusion.

[0028] Particularly advantageous is the tool holder extrusion channel located in the first clamping flange of the tool holder. This feature allows for a simple conveyor connection of the tool holder extrusion channel to the screw cylinder.

[0029] In a further preferred embodiment of the invention, the extrusion tool is designed to be identical in shape to the cavity of the tool holder. This facilitates the positioning and securing of the extrusion tool in the cavity of the tool holder.

[0030] Particularly advantageously, the extrusion tool has a cuboid or cylindrical shape, except for the projections on the base body in and against the axial extrusion direction. In particular, the base body of the extrusion tool has a cuboid or cylindrical shape. As already explained, the extrusion tool is designed in the form of a cassette, i.e. as a one-piece insert for insertion into the cavity of the tool holder. Both the cuboid and the cylindrical shape enable easy handling of the extrusion tool, in particular in an automated manner using a program-controlled robot arm. In addition, such extrusion tools can be easily fed into space-saving storage, in particular by stacking, which applies particularly to the cuboid shape.A cylindrical extrusion die with a correspondingly shaped cavity in the die holder has the particular advantage that the cavity, which has a round cross-section and no corners, is easily accessible for cleaning. With a cuboid base part, the projections are preferably cuboid. Similarly, with a cylindrical base part, the projections are preferably cylindrical.

[0031] In a further preferred embodiment of the invention, the extrusion tool can be or is fixed to the tool holder in such a way that there is a gap or play between the tool holder and the extrusion tool. It is understood that because the extrusion tool is fixed to the tool holder, there is only limited play between the extrusion tool and the tool holder, i.e. the extrusion tool has one or more areas in each of which there is a gap to the tool holder. This measure advantageously makes it possible to compensate for thermal expansion of the extrusion tool in order to avoid thermal stresses in the extruder head. The extrusion tool is fixed to the axial stops on the tool holder by clamping and particularly preferably has play in the radial direction relative to the tool holder.On the one hand, the extrusion tool can then be reliably and securely positioned in the cavity of the tool holder and secured to the tool holder, and on the other hand, thermal expansion of the extrusion tool in the radial direction can be well compensated for. This embodiment is particularly advantageous because the tool holder has a base part surrounding the cavity and a cover for closing the cavity, wherein the extrusion tool can be secured to the tool holder by means of the cover mounted on the base part and pressure exerted by the cover by means of clamping. It is also particularly advantageous that the extrusion tool has a first projection on the base body in the extrusion direction and a second projection opposite to the axial extrusion direction, wherein the projections can each be brought into engagement with or are in engagement with a projection receptacle of the tool holder that is designed to fit snugly.In a further preferred embodiment of the invention, the tool holder is equipped with a heating means, for example a heating band, for actively heating the extrusion tool. This measure advantageously enables heating of the extrusion tool, in particular to extrude plastics or polymer materials at elevated temperatures. The heating means can be based on any suitable heating technology and can, in particular, comprise heating elements in the form of heating wires for electrical resistance heating or heating lines for a circulating heating fluid. Various possibilities for implementing such a heating means are known to those skilled in the art, and their implementation is within the skill of the skilled person, so this need not be explained in more detail here.

[0032] The invention further extends to an extruder with a screw barrel and an extruder head arranged downstream of the screw barrel in the axial extrusion direction, as described above. The screw barrel has a motor-driven, axially rotatable screw in a (hollow) cylinder in order to homogenize and compress the material fed in as bulk material, e.g. in the form of a powder or granulate. The screw barrel is advantageously provided with a heating means, for example a heating band, for actively heating the material to be extruded. It is understood that the extruder can contain further components, which, however, need not be discussed in the context of the present description of the invention, since they are not necessary for understanding the invention.

[0033] The extruder according to the invention can be used in particular for producing profile strands for spacers for insulating glazing made of a polymer material. For example, a profile strand contains or consists of polyethylene (PE), polycarbonate (PC), polypropylene (PP), polystyrene, polyester, polyethylene terephthalate (PET), polyethylene terephthalate glycol (PET-G), polyoxymethylene (POM), polyamide, polyamide-6,6, polybutylene terephthalate (PBT), acrylonitrile butadiene styrene (ABS), acrylate ester styrene acrylonitrile (ASA), acrylonitrile butadiene styrene polycarbonate (ABS / PC), styrene acrylonitrile (SAN), PET / PC, PBT / PC, or copolymers thereof. The polymer material may be glass fiber reinforced to simultaneously improve strength and stability, for example a glass fiber content of 20 wt.% to 50 wt.%, in particular 30 wt.% to 40 wt.%, may be provided.

[0034] For spacers for insulating glazing, a profile strand can, for example, have a width of 5 mm to 55 mm, in particular 10 mm to 20 mm, measured perpendicular to the extension of the profile strand. The width determines the distance between the panes of the insulating glazing, and the width is dependent on the dimensions of the insulating glazing and the desired size between the panes. For spacers for insulating glazing, a profile strand can, for example, have a height of 5 mm to 15 mm, in particular 6 mm to 10 mm, measured perpendicular to the extension of the profile strand and perpendicular to the width. In this height range, the spacer has advantageous stability, but on the other hand is inconspicuous in the insulating glazing. In addition, the cavity of the spacer then has an advantageous size to accommodate a suitable amount of desiccant.

[0035] Furthermore, the invention extends to the use of the extruder head according to the invention, as well as the extruder according to the invention, for producing a profile strand for spacers, in particular spacers made of a polymer material, for insulating glazing.

[0036] The various embodiments of the invention can be implemented individually or in any combination. In particular, the features mentioned above and explained below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

[0037] The invention is explained in more detail below using exemplary embodiments, with reference to the accompanying figures. They show, in simplified form and not to scale:

[0038] Fig. 1 is a schematic cross-sectional view of an exemplary embodiment of the extruder according to the invention with a mounted extruder head for extruding profile strands,

[0039] Fig. 2A-2C various schematic views of components of an exemplary embodiment of the extruder head,

[0040] Fig. 3A-3B various schematic views of the extruder head of Fig. 2A-2C in the assembled state,

[0041] Fig. 4 is a schematic perspective view of components of an alternative exemplary embodiment of the extruder head. Figures 1 to 4 illustrate the extruder, designated overall by reference number 100 (see Figure 1), and the extruder head 1 mounted in the extruder (see Figures 2 to 4) using various exemplary embodiments.

[0042] Consider first Figure 1, in which an exemplary embodiment of the extruder 100 according to the invention for extruding profile strands, in particular for producing spacers for insulating glazing, which preferably consist of a polymer material (e.g. SAN), is illustrated by means of a schematic cross-sectional view.

[0043] As shown in Figure 1, the extruder 100 comprises an end-mounted extruder head 1 for forming and dispensing extruded profile strands, which is arranged axially (in the axial extrusion direction) downstream of a screw cylinder 101 in the extrusion direction. The extrusion direction (conveying direction) is from left to right in Figure 1. The screw cylinder 101 comprises a screw 102, which is arranged axially rotatably in a (hollow) cylinder 103 and can be set into axial rotation by an (electric) motor 104. A hopper 105 opens into the interior of the cylinder 103, through which polymer material in the form of bulk material (e.g. powder or granules) can be fed. This is illustrated in Figure 1 by the arrow pointing into the hopper. The axial rotation of the screw 102 homogenizes and compresses the polymer material.Not shown is a heating means, typically a heating band, which is arranged circumferentially around the screw barrel 101 and by which the polymer material can be heated. For example, SAN is extruded at a temperature of approximately 210°C. Between the screw barrel 101 and the extruder head 1 is a melt pump 106, symbolized by intermeshing gears, which serves to convey the polymer material into the extruder head 1 and to further compress the polymer material. The polymer material is discharged from the extruder head 1 in the form of a profile strand with the desired profile, which is illustrated in Figure 1 by the arrow pointing away from the extruder head 1.

[0044] Figures 2A-2C schematically illustrate an exemplary embodiment of the extruder head 1 of the extruder 100 of Figure 1. The extruder head 1 comprises a tool holder 2, which defines a cavity 3 for an extrusion tool 4 that can be inserted into the cavity 3. The tool holder 2 is shown in a schematic cross-sectional view in Figure 2A. The extrusion tool 4 is illustrated in Figure 2B using a schematic cross-sectional view and in Figure 2C using a schematic perspective view. The extrusion tool 4 is provided here, for example, with two tool extrusion channels 5, each of which serves to shape and deliver an extruded profile strand (not shown). It would equally be possible for the extrusion tool 4 to have a smaller or larger number of tool extrusion channels 5.The tool extrusion channels 5 can be seen in the schematic cross-sectional view of Figure 2B and the perspective view of Figure 2C of the extrusion tool 4. The tool extrusion channels 5, which are arranged side by side in the same (e.g., horizontal) plane, are connected to the screw cylinder 101 for conveying purposes at a respective inner channel opening 6, which will be explained in more detail below. The extruded profile strand can be discharged from the extruder head 1 or extruder 100 at a respective outer channel opening 7.

[0045] The extrusion tool 4 is designed in the form of a cassette (i.e. in the form of a one-piece insert part) for insertion or pushing into the cavity 3 of the tool holder 2. The extrusion tool is therefore a single part that is relatively easy to handle and comparatively lightweight. The extrusion tool 4 has a base body 8 that has a box or cuboid shape. In addition, the extrusion tool 4 has two end-face projections 9, 9' in the axial direction (relative to the axial direction of the screw 102 of the screw cylinder 101), with a first projection 9 protruding from the cuboid base body 8 in the axial extrusion direction and a second projection 9' protruding against the axial extrusion direction. In the perspective view of Figure 2C, only the first projection 9 is visible.

[0046] The two projections 9, 9' are cuboid-shaped here, for example, and each have an end face 10, 10', with a first end face 10 on the first projection 9 and a second end face 10' on the second projection 9'. The two end faces 10, 10' face away from one another. The size of the two cuboid-shaped projections 9, 9' is reduced in the radial direction (relative to the radial direction of the screw 102 of the screw cylinder 101) compared to the size of the cuboid-shaped base body 8, so that two stops 11, 11' are formed on the end face of the base body 8, with a first stop 11 pointing in the extrusion direction and a second stop 11' pointing opposite the extrusion direction. The two stops 11, 11' face away from one another.The two tool extrusion channels 5 each extend over the complete axial length of the extrusion tool 4 from the first end face 10 of the first projection 9 to the second end face 10' of the second projection 9', wherein the outer channel openings 7 are arranged on the first end face 10 and inner channel openings 6 are arranged on the second end face 10'.

[0047] As shown in Figure 2A, the tool holder 2 comprises a base part 14 surrounding the cavity 3 and a cover 15 through which the cavity 3 can be closed from the outside. The cover 15 can be attached to the base part 14, for example, by screws 22 (see Figure 4), which can be inserted into corresponding screw receptacles 16.

[0048] The cavity 3 of the tool holder 3 is designed in the form of a cassette receptacle, so that the extrusion tool 4 designed in the form of a cassette can be easily inserted into the cavity 3 and secured to the tool holder 2. The cavity 3 is designed to fit the extrusion tool 4, whereby, when the extrusion tool 4 is inserted, the base body 8 lies in a corresponding base body receptacle 12 of the cavity 3 and the projections 9, 9' lie in corresponding projection receptacles 13, 13' of the cavity 3.

[0049] The base part 14 of the tool holder 2 has a first clamping flange 17, which can be screwed to a matching second clamping flange 107 to mount the extruder head 1 in the extruder 100. This is illustrated in Figure 1. Figure 2A shows the screw receptacles 16 in the first clamping flange 17.

[0050] Also visible in Figure 2A is a tool holder extrusion channel 18 formed in the first clamping flange 17, which is nozzle-shaped or conical and, when the extrusion tool 4 is inserted into the cavity 3, is connected in terms of conveying technology to the inner channel openings 6 of the two tool extrusion channels 5.

[0051] Figure 3A illustrates the assembled state of the extrusion head 1 using a schematic cross-sectional view. Figure 3B shows a front view of the extrusion head 1, viewed opposite the axial extrusion direction. The extrusion tool 4 is inserted into the cavity 3 of the tool holder 2, with the base body 8 arranged in the matching base body receptacle 12 and the projections 9, 9' arranged in the matching projection receptacles 13, 13'. The nozzle-shaped tool holder extrusion channel 18 opens into the two tool extrusion channels 5.When the extrusion head 1 is mounted in the extruder 100, the nozzle-shaped tool holder extrusion channel 18 is connected to the screw cylinder 101 in terms of conveying technology, as illustrated in Figure 1, so that material to be extruded can be conveyed from the screw cylinder 101 via the nozzle-shaped tool holder extrusion channel 18 into the two tool extrusion channels 5, wherein the shaping of the profile strands that ultimately emerge at the outer channel openings 7 takes place in the two tool extrusion channels 5.

[0052] The extrusion tool 4 is positioned in the cavity 3 by the projections 9, 9'. The extrusion tool 4 is fixed to the tool holder 2 by the cover 15, which is screwed to the base part 14 by means of screws 16, wherein the cover 15 exerts mechanical pressure on the extrusion tool 4 in the axial direction (opposite the axial extrusion direction). The stops 11, 11' of the extrusion tool 4 are pressed against corresponding abutting surfaces 19, 19' of the base part 14 and cover 15, so that the extrusion tool 4 is fixed to the tool holder 2 by an axial clamping (clamping). In the radial direction, the extrusion tool 4 is accommodated in the area of ​​the base body 8 with a radial clearance or play 20 to the wall of the cavity 3 in the base body holder 12, whereby a thermal expansion of the extrusion tool 4 can be compensated.

[0053] In Figures 3A and 3B, the screw receptacles 16 for fastening the first flange 17 and the cover 15 using screws 22 (see Figure 4) are clearly visible. Furthermore, it is clearly visible that the first projection 9 engages through a projection receptacle 13 formed in the form of an opening 21 in the cover 15, allowing the extruded profile strands to be discharged to the outside.

[0054] The extrusion tool 4, designed in the form of a cassette, can be easily inserted into the cavity 3, positioned by the projections 9, 9', and secured to the tool holder 2 by the cover 15 mounted on the base part 14. Conversely, the extrusion tool 4 can be easily released from its attachment to the tool holder 2 by unscrewing the cover 15 and removed from the cavity 3 in order to change the extrusion tool 4 for the extrusion of profile strands with other profile shapes or to replace it in the event of wear or a defect. The tool holder 2 can remain mounted in the extruder 100. Thus, the extruder head 1 represents a quick-change system for the simple and rapid changing or replacement of extrusion tools 4. Since the extrusion tool 4 is significantly lighter than the extruder head 1, manual handling by a worker is considerably facilitated.In addition, the extrusion tool 4 can be heated to a suitable temperature for the extrusion of the polymer material before being inserted into the cavity 3, so that the extrusion can be continued quickly.

[0055] Not shown in the figures is a heating means, such as a heating band, which is arranged around the base part 14 of the tool holder 1 and by means of which the extrusion tool 4 can be heated.

[0056] Figure 4 shows an alternative exemplary embodiment of the extruder head of Figures 2 and 3. To avoid unnecessary repetition, only the differences to the embodiment of Figures 2 and 3 are explained, and otherwise reference is made to the above explanations. Accordingly, the extrusion tool 4 does not have a cuboid shape, but a round shape in cross-section. Accordingly, the base body 8 and the projections 9, 9' are each cylindrical, with the cavity 3 having a matching cylindrical shape. Likewise, the cover 15 is designed with a disc shape with a round cross-section. In contrast to the previous embodiment of the extrusion tool 4, it has only a single tool extrusion channel 5, so that only a single profile strand can be extruded. However, it would also be conceivable and possible to provide multiple tool extrusion channels 5.Figure 4 also shows screws 22 for fastening the cover 15 to the base part 14.

[0057] From the above, it can be seen that the invention provides an improved extrusion head, which forms a quick-change system for the rapid change or replacement of extrusion tools. This significantly simplifies, in particular, the production of differently shaped profile strands for spacers for insulating glazing and enables the time- and cost-efficient production of spacers with different profiles. Handling extrusion tools while the tool holder is still mounted in the extruder significantly simplifies work. In addition, extrusion tools can be heated before being inserted into the tool holder in order to keep downtime during extrusion due to tool changes as short as possible. List of Reference Symbols

[0058] 1 extruder head

[0059] 2 tool holders

[0060] 3 Cavity

[0061] 4 Extrusion tool

[0062] 5 Tool extrusion channel

[0063] 6 inner canal mouth

[0064] 7 outer canal mouth

[0065] 8 base body 9, 9' projection

[0066] 10, 10' frontal area

[0067] 11 , 11' stop

[0068] 12 base body holder 13,13' projection holder

[0069] 14 Base part

[0070] 15 lids

[0071] 16 screw receptacles

[0072] 17 first clamping flange

[0073] 18 Tool holder extrusion channel

[0074] 19.19' impact area

[0075] 20 game

[0076] 21 Opening

[0077] 22 Screw

[0078] 100 extruders

[0079] 101 screw cylinders

[0080] 102 Snail

[0081] 103 cylinders

[0082] 104 Engine

[0083] 105 funnels

[0084] 106 Melt pump

[0085] 107 second clamping flange

Claims

Patent claims 1 . A mountable extruder head (1) for an extruder (100) intended to be arranged downstream of a screw cylinder (101) in the axial extrusion direction, comprising: a tool holder (2) with a cavity (3) for at least one extrusion tool (4), at least one extrusion tool (4) which is provided with at least one tool extrusion channel (5) which can be connected to the screw cylinder (101) for conveying purposes, for forming a profile strand, and an outer channel opening (7) for discharging the profile strand, wherein the tool holder (2) has a base part (14) surrounding the cavity (3) and a cover (15) for closing the cavity (3), the extrusion tool (4) is designed in the form of a cassette, and the cavity (3) of the tool holder (2) is designed in the form of a cassette receptacle, such that the extrusion tool (4) can be inserted into the cavity (3) counter to the axial extrusion direction,the extrusion tool (4) has stops (11, 11') in the axial extrusion direction and counter to the axial extrusion direction, by means of which the extrusion tool (4) can be clamped to the tool holder (2) by pressure exerted by the cover (15), the extrusion tool (4) has a base body (8) and a first projection (9) projecting from the base body (8) in the axial extrusion direction and a second projection (9') projecting from the base body (8) counter to the axial extrusion direction, wherein the projections (9, 9') can each be brought into engagement with a projection receptacle (13, 13') of the tool holder (2) formed in a snug fit, wherein the projections (9, 9') each have a smaller dimension in the radial direction than the base body (8), and wherein the projections (9, 9') each contain a region of the at least one tool extrusion channel (5).

2. Mountable extruder head (1) according to claim 1, wherein the extrusion tool (4) can be fixed to the tool holder (2) in such a way that the extrusion tool (4) has play (20) in some areas relative to the tool holder (2), in particular in the radial direction.

3. Mountable extruder head (1 ) according to one of claims 1 or 2, wherein the first projection (9) in the axial extrusion direction through a in the form of an opening (21 ) of the Cover (15) formed projection receptacle (13) and has the outer channel mouth (7) for the exit of the extrusion profile from the extrusion head (1).

4. Mountable extruder head (1) according to one of claims 1 to 3, wherein the extrusion tool (4) can be fixed exclusively to the stops (11, 11') on the tool holder (2) by clamping.

5. Mountable extruder head (1) according to one of claims 1 to 4, in which the stops (11, 11') of the extrusion tool (4) result from the fact that the projections (9, 9') each have a smaller dimension in the radial direction than the base body (8).

6. Mountable extruder head (1) according to one of claims 1 to 5, wherein the at least one tool extrusion channel (5) extends over a complete length of the extrusion tool (4) in the axial extrusion direction from a first end face (10) of the first projection (9) to a second end face (10') of the second projection (9').

7. Mountable extruder head (1) according to one of claims 1 to 6, wherein the tool holder (2) is provided with a tool holder extrusion channel (18), wherein the tool holder extrusion channel (18) can be connected to the at least one tool extrusion channel (5) of the extrusion tool (4) in terms of conveying technology.

8. Mountable extruder head (1) according to claim 7, wherein the tool holder (2) and the extrusion tool (4) are designed such that the at least one tool extrusion channel (5) automatically comes into a conveying connection with the tool holder extrusion channel (18) when the extrusion tool (4) is inserted into the cavity (3) of the tool holder (2) and is fixed to the tool holder (2).

9. Mountable extruder head (1) according to one of claims 1 to 8, wherein the tool holder (2) is provided with a first clamping flange (17) for connection to a second clamping flange (107) of the extruder (100).

10. Mountable extruder head (1) according to claim 8 and 9, wherein the tool holder extrusion channel (18) is formed in the first clamping flange (17) of the tool holder (2).

11. Mountable extruder head (1) according to one of claims 1 to 10, wherein the Extrusion tool (4), except for the projections (9, 9'), has a cuboid or cylindrical shape.

12. Mountable extruder head (1) according to one of claims 1 to 11, in which the tool holder (2) is provided with a heating means, in particular a heating band, for active Heating of the extrusion tool (4).

13. Extruder (100) comprising a screw cylinder (101) and an extruder head (1) according to one of claims 1 to 12 arranged downstream of the screw cylinder (101) in the axial extrusion direction.

14. Use of the mountable extruder head (1) according to one of claims 1 to 12, and of the extruder (100) according to claim 13, for producing a profile strand for spacers for insulating glazing.

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