阅读说明：本技术 带冷却或加热介质引导的挤出滚筒 (With cooling or heating medium-guiding extrusion cylinders ) 是由 格杰特·克里斯蒂安·普林克 凡妮莎·斯塔贝 里昂·贾斯帕·泰兹 于 2020-04-08 设计创作，主要内容包括：一种挤出滚筒(100),具有用于容纳挤出机螺杆的滚筒体(110),其特征在于,所述滚筒体(110)的外壁(115)具有至少一个内凹(120),该内凹可以被遮盖,并且在被遮盖的状态下适合于引导用于对所述滚筒体(110)调温的冷却或加热介质。(An extrusion drum (100) having a drum body (110) for accommodating an extruder screw, characterized in that an outer wall (115) of the drum body (110) has at least one indentation (120) which can be covered and which, in the covered state, is suitable for guiding a cooling or heating medium for tempering the drum body (110).)

1. An extrusion drum (100) having a drum body (110) for accommodating an extruder screw, characterized in that an outer wall (115) of the drum body (110) has at least one indentation (120) which can be covered and which, in the covered state, is suitable for guiding a cooling or heating medium for tempering the drum body (110).

2. The extrusion drum (100) according to claim 1, further comprising a cover portion (130) connected to the outer wall (115) of the drum body (110) such that the cover portion covers the at least one recess (120).

3. The extrusion drum (100) according to any one of the preceding claims, wherein the at least one recess (120) has a straight section (122) extending parallel to the longitudinal axis of the drum body (110) and a curved section (124) establishing a connection between two adjacent ends of exactly two straight sections (122); a flow path without branching is defined by connecting the linear member (122) and the curved member (124).

4. The extrusion drum (100) according to claim 3, wherein the straight section (122) extends from at least one edge region (112) of the drum body (110) and a portion of the curved section (124) is arranged in the edge region (112) of the drum body (110).

5. The extrusion drum (100) according to claim 4, further having at least one connecting flange (140) which is arranged by press fit onto an edge region (112) of the drum body (110) in such a way that it covers at least the curved section (124) located in the edge region (112).

6. The extrusion drum (100) according to claim 5, wherein the connection flange (140) has a line enabling the introduction of a cooling or heating medium into the recess (120) and out of the recess (120).

7. The extrusion drum (100) according to any one of claims 4 to 6, wherein the straight section (122) extends from an edge region (112) of the drum body (110) for a predetermined length, which is less than the length of the drum body (110).

8. The extrusion drum (100) according to claim 3, wherein the straight section (122) does not extend to an edge region (112) of the drum body (110).

9. The extrusion drum (100) according to claim 7 or 8, wherein at least two connection locations (150) for introducing and discharging a cooling or heating medium into and out of the recess (120) are provided on the drum body (110).

10. The extrusion drum (100) according to any one of the preceding claims, wherein the outer wall (115) of the drum body (110) has a plurality of said dimples (120) which are not interconnected and which in a covered state define their own flow path for a cooling or heating medium, respectively.

11. The extrusion drum (100) according to any one of the preceding claims, wherein the drum body (110) has a plurality of radial bores adapted to receive pins or screws and arranged in a different position than at least one of the recesses (120).

12. An extrusion apparatus having:

the extrusion drum (100) according to any one of the preceding claims, wherein at least one recess (120) is covered; and

a cooling or heating medium flowing in at least one of the covered recesses (120).

13. The extrusion apparatus of claim 12, further comprising

Each temperature control means for each recess (120) for controlling the temperature of a cooling or heating medium flowing in the respective recess (120).

14. Method for manufacturing an extrusion drum (100) according to any one of claims 1 to 11, comprising the steps of:

at least one indentation (120) is created in the outer wall (115) of the drum body (110).

15. The manufacturing method of claim 14, further comprising the steps of:

covering at least one of said recesses (120) with a cover part (130).

Technical Field

The invention relates to an extrusion cylinder which can be tempered in an efficient manner and to a method for producing such an extrusion cylinder.

Background

In the extrusion field, it is often necessary to temper the extrusion cylinders in which the extruder screws tumble the extrudate for guiding and mixing the extrudate. In particular, in rubber extrusion, it is advantageous to first preheat the extrusion cylinder in order to bring the extrudate into a plastically deformable state more quickly. However, in a subsequent process, some of the heat generated upon conveyance/mixing of the extrudate must be discharged again. Usually, a cooling or heating medium is used here, for example water or the like, which is led to the extrusion drum via a line and serves as a heat exchanger.

In order to make the heat exchange as efficient as possible, it is suggested to bring the heat exchanger in direct contact with the drum body. For this purpose, peripheral holes through the drum are currently used. However, since such deep hole drilling for a large drilling depth cannot be performed with sufficient accuracy, the axial length of the drum body provided with the peripheral hole is limited. Since the length of the extrusion cylinder is usually longer than can be controlled by means of the peripheral holes, it is necessary to assemble the extrusion cylinder from several separate parts. This is accomplished by connecting flanges at the ends of the respective drum segments.

In addition to the high manufacturing and assembly costs of such drum segment systems, there are other problems.

On the one hand, it is desirable to avoid pressure losses of the tempering medium due to excessive deflection in the tempering channel. However, the currently employed drilling cannot achieve this. Rather, a sudden deflection of 180 ° often occurs in the connection flange. There is also no closed path within the tempering system. Specifically, the tempering system is divided into several circuits with non-directional flow. This makes tempering difficult to manage and control and has to be carried out at high pressure.

Another problem is that the distribution of the different tempering zones, i.e. the setting of different temperatures along the extrusion cylinder, must be based on the length of the individual cylinder segments. The temperature zones cannot be established and located at will.

For mixing extrudates (e.g. rubber) with a higher viscosity, it is also advantageous to screw the pins from the outside into the interior of the extrusion drum. These pins protrude into the extrudate and, in cooperation with the movement of the extruder screw, promote mixing and plasticization of the extrudate. For optimum results, the pins should be distributed as evenly as possible along the length of the extrusion cylinder. However, if the extrusion cylinder is divided into several segments which are connected by flanges, the pins cannot be used in the region of the flanges. This may slow down or even deteriorate the extrusion process.

The tempering systems currently used for extrusion drums therefore result in a lack of flexibility in the tempering of the drums and in the arrangement of the pins in the drums that facilitate the mixing of the extrudate. Furthermore, the production of the extrusion cylinders from a plurality of segments provided with deep holes is error-prone and costly. The operation of such a tempering system is also complicated by high pressure losses and non-directional flow guidance in the bore.

Disclosure of Invention

The object of the present invention is to propose an extrusion cylinder with which at least some, preferably all, of the above-mentioned problems are solved. The invention also relates to a method for producing such an extrusion cylinder.

This object is achieved by the subject matter of the independent claims.

An extrusion drum, which may have a drum body for accommodating an extruder screw, characterized in that the outer wall of the drum body has at least one indentation, which can be covered and, in the covered state, is suitable for guiding a cooling or heating medium for tempering the drum body.

Instead of providing holes in the interior of the drum body, recesses are thus produced in the outer wall of the drum body, for example by milling one or more continuous grooves in the outer wall of the drum body. The recesses must be dimensioned such that a cooling or heating medium (for example water or a similar heat exchange liquid) which can be used for the tempering drum body can flow through the recesses when they are covered, without excessive pressure losses. The recess may have a substantially rectangular cross section, the width and/or height of which is 0.5 to 6cm, for example 1cm, 3cm or 5 cm. However, the cross-section may also have any other shape of similar area.

Thus, a line for the temperature control agent can be produced in a simple manner on the outside of the drum body. This eliminates substantially all of the limitations on cooling path geometry that result from the use of drilled holes. It is particularly possible to recess drum segments from the outside which are much longer than possible by way of the through-openings. The entire extrusion cylinder can thus be produced from one piece or from only a few segments. This allows increasing the number of pins provided for mixing/plasticizing, thereby improving the quality of the extrudate.

Furthermore, when the temperature control line is formed externally as a recess in the outer wall of the drum, the course of the line can be determined essentially freely. The recess may then, for example, spirally surround the drum. This makes it possible to produce well-defined flow paths for the cooling or heating medium, in which flow paths only a slight pressure drop occurs. This facilitates setting the drum body to a specific temperature.

Although the above-mentioned advantages have already been achieved by providing only a coverable recess, the extrusion drum can also have covering parts which are connected to the outer wall of the drum body in such a way that they cover the at least one recess. This allows a cooling or heating medium to be guided through the recess. The covering is preferably accomplished by welding a metal plate on the side of the upwardly opening recess. However, the drum body provided with the recess can also be pushed into a sleeve, for example a sheet metal sleeve, which sealingly closes all recesses, for example as a result of a press fit. An inlet and an outlet for a cooling or heating medium can then be provided in the sleeve.

At least one recess may have straight sections extending parallel to the longitudinal axis of the drum body and curved sections establishing a connection between two adjacent ends of exactly two straight sections. By connecting the straight line member and the curved member, a flow path without branching can be defined.

The dimples can then be said to extend "in a serpentine" around the drum body. Starting from the entry point for the cooling or heating medium, the recess extends first in the axial direction. At the end of this straight section, a curved section is adjacent, which is guided concavely in the circumferential direction of the drum body, so that no pressure loss occurs. The radius of the curved section can be 1 to 6cm, for example 2cm, 3cm, 4cm or 5 cm. At the end of the curved section, a straight section is again adjacent, which extends back in the axial direction. This alternation of the curved sections and the radial sections continues as far as the outlet for the cooling or heating medium, preferably in such a way that the recess surrounds the entire circumference of the drum body like a sleeve. In this way, a flow path can be defined in a simple manner, which allows an optimum tempering of the drum body without excessive pressure losses.

The straight section may extend from at least one edge region of the drum body, and a portion of the curved section may be disposed in the edge region of the drum body. This allows for example to feed a cooling or heating medium from the edge of the drum body. The width of the edge region from the end of the roller body may be, for example, one thirtieth, one twentieth, one tenth or one fifth of the total length of the roller body.

The extrusion drum can also have at least one connecting flange which is arranged by press fit on the edge region of the drum body in such a way that it covers at least the curved section located in the edge region. Thus, the connecting flange itself can serve as a cover part. Thereby limiting material consumption. The connecting flange can be a flange for connecting a plurality of drum body sections or a flange for connecting an extrudate inlet or outlet in an extrusion drum. The extrusion cylinder can thus be used both as a section of a longer cylinder in the conventional manner and as a separate extrusion cylinder. However, the decision as to the use or length of the drum is no longer subject to technical constraints, but is only determined by the needs of the operator of the extrusion apparatus comprising the drum.

The connecting flange can have lines which enable a cooling or heating medium to be introduced into and removed from the recess. In this way, the supply and discharge of the cooling and heating medium can be ensured in a simple manner without further components.

The linear section may extend from an edge region of the drum body by a predetermined length, which is less than the length of the drum body. For example, the linear section may be only three-quarters, two-thirds, one-half, one-third, or one-fourth of the total length of the drum body. The corresponding recess is then suitable for the temperature control of this length range of the drum body. This allows for a flexible temperature setting of the drum body.

The linear section may not extend to the edge region of the drum body. That is to say that the recess extends, for example, only in the central region of the drum body. The distance of the recess from one or both ends of the roller body may also be, for example, one sixth, one quarter or one third of the total length of the roller body. This allows for separate tempering of the central part of the drum body. Flexible temperature settings can thereby also be achieved.

At least two connection points for introducing and discharging a cooling or heating medium into and out of the recess can be provided on the drum body. The supply and discharge of the cooling or heating medium then does not have to take place along the edge region of the drum body, but can in principle take place anywhere on the drum body. For example, it is also possible to use, as connection points, openings in the flange which are arranged at the end of the drum body and to arrange further connection points for the same temperature control medium channel on the drum body. This also allows for more flexible temperature settings.

The outer wall of the drum body may have a plurality of recesses which are not connected to one another and which, in the covered state, respectively define their own flow path for the cooling or heating medium. This allows different, non-communicating tempering circuits to be provided, which can set the drum body to different temperatures in the region thereof. This also allows for more flexible temperature settings.

The roller body may have a plurality of radial bores adapted to receive pins or screws. The bore may be disposed in a different location than the at least one dimple. The extrusion cylinder, which can be temperature-controlled in a simple manner, can also be equipped in this way with pins, screws, bolts or the like, which project into the passage region of the extrudate, so that plasticization and mixing of the extrudate is promoted. The bores provided for this purpose can be distributed along the entire surface of the extrusion cylinder, so that a uniform influence on the extrudate can be achieved. If the bore does not overlap the recess, i.e. the passage for the cooling or heating medium, the pin or screw inserted therein can be simply replaced without having to interrupt the tempering circuit. On the other hand, it is also possible to seal the bores against the temperature control medium after the screws have been inserted, so that they can also be arranged in the recessed region, if necessary.

The extrusion device may have an extrusion cylinder as described above, at least one recess of which is covered. Furthermore, the extrusion device can have a cooling or heating medium flowing in the at least one covered recess. This achieves the above-mentioned advantages in the operation of the extrusion device.

Furthermore, the extrusion device may have for each recess, respectively, a temperature control means adapted to control the temperature of the cooling or heating medium flowing in the respective recess. Thus, extrusion can be carried out using an extrusion cylinder adjustable to different temperature zones.

The manufacturing method for the extrusion cylinder as described above may include: at least one recess is produced in the outer wall of the drum body, for example by milling. The manufacturing method may further include: the at least one recess is covered by a covering part, for example a metal plate. This enables simple manufacture of the extrusion cylinder using standard processes.

Drawings

The present invention is described in detail below with reference to the accompanying drawings. This description is purely exemplary. The invention itself should only be determined by the subject matter of the claims.

FIGS. 1A to 1C show various schematic views of an extrusion cylinder;

FIGS. 2A and 2B show various schematic views of another extrusion cylinder;

FIG. 3 is a schematic view of another extrusion cylinder;

FIGS. 4A and 4B show different views of an additional extrusion cylinder;

FIG. 5 is a schematic view of another extrusion cylinder;

FIGS. 6A and 6B are schematic views of another extrusion cylinder;

FIG. 7 is a schematic view of another extrusion cylinder; and

fig. 8 shows a schematic flow diagram of a production method of an extrusion cylinder.

Detailed Description

Fig. 1A to 1C show various schematic views of an extrusion cylinder 100. Fig. 1A shows an oblique view, fig. 1B shows a cross section of the extrusion cylinder 100, and fig. 1C shows a side view of the extrusion cylinder 100.

The extrusion cylinder 100 consists essentially of a cylinder body 110, preferably made of metal, which is designed as a hollow cylinder. The drum body 110 has an outer wall 115 corresponding to the outer shell surface of the hollow drum. The drum body 110 is provided with an interior space 118 for receiving an extruder screw suitable for guiding, plasticizing and mixing extrudate, such as rubber, green rubber, etc.

The dimensions of the extrusion cylinder 100 correspond to those usually used for extrusion and depend substantially on the substance to be extruded. Typical dimensions for the total length of the extrusion cylinder for rubber extrusion are approximately in the range of 1 to 5 meters, i.e. may be 1m, 2m, 3m, 4m or 5m, for example. But longer extrusion cylinders are also conceivable.

The length of the extrusion cylinder 100 may be equal to the total length required for extrusion. However, the extrusion cylinder 100 can also be a section of the entire extrusion cylinder, which then consists of a plurality of extrusion cylinders. One or more of these drums may correspond to the extrusion drum 100 or a variation of the drum discussed below.

Typical dimensions for the outer radius of the roller body 110 for rubber extrusion are in the range of 20 to 50cm, for example 25cm, 30cm, 35cm, 40cm or 45 cm. Possible inner radii are in the range of 4.5cm to 30cm, for example 5cm, 10cm, 15cm, 20cm or 25 cm. Accordingly, the wall thickness of the roller body 110 is in the range of 3cm to 10cm, for example 5cm or 7 cm. The ratio of length to diameter may be, for example, between 10:1 and 3:1, such as about 4:1, 6:1, 7:1 or 8: 1.

The roller body 110 has at least one recess 120 in its outer wall 115. As shown in fig. 1A-1C, this may be a single, continuous indentation 120 extending around the entire roller body 110. The recess 120 is designed in particular with regard to its width and depth such that a cooling or heating medium, hereinafter referred to as a temperature control medium, for example water or the like, can flow through the recess 120 unimpeded, i.e. without excessive pressure losses. Furthermore, by means of the recess, a flow path is defined in the direction of the outer wall 115 of the drum body 110, which flow path is as far as possible non-divergent or can be easily controlled or regulated by means of the flow parameters of the temperature control medium-and thus by means of the heat exchange with the drum body 110-for example by means of the position of a valve or the delivery rate of a pump.

As shown in fig. 1B, the depth of the recess 120 may correspond to more than half of the wall thickness of the roller body 110. The width of the recess can be approximately equal to its depth, but can also differ from its depth. For example, in the case of a wall thickness of about 5cm, the width of the recess 120 may be in the range of about 2cm to 4cm, for example 3 cm. The depth of the recess 120 is then also in the range of 2cm to 4cm, for example also 3cm or 3.5 cm. If the wall thickness of the roller body 110 is different, the dimensions mentioned for the recess 120 may remain the same or be adjusted proportionally. Instead of the cross-sectional shape of the recess 120 shown in fig. 1B, the recess may also have any other cross-section that is easy to manufacture, for example a triangular shape or a shape of a part of a circle, such as a semi-circle.

As shown in fig. 1A and 1C, the dimple 120 may be comprised of a straight section 122 and a curved section 124. Here, the linear section 122 extends axially along the outer wall 115 of the drum body 110. As shown, these linear sections may extend from the edge region 112 of the drum body 110 to, for example, an opposite edge region. A bending section 124 is arranged in the edge region 112. These curved sections respectively connect adjacent ends of exactly two straight sections 122 to each other. The recess 120 has an unbranched course, since the curved sections 124 are arranged alternately in one or the other edge region 112, respectively. That is, the temperature-regulating medium can be guided in a well-defined manner from the beginning of the recess 120 to its end.

In the region of the straight section 122, there is little resistance to the flow of the temperature-regulating medium. There is essentially only resistance due to friction on the walls of the dimple 120. The pressure loss along the straight section 122 is relatively small.

The dimples 120 are also formed in the edge region 112 of the roller body 110 without abrupt transitions or edges. As a result, the flow resistance at the transition between the two straight sections 122 remains low. As shown, the curved section 124 for this purpose can be designed as a circular arc. The radius of the curved section 124 is selected to minimize flow resistance. Here, the radius may be in the range of 1cm to 10cm depending on the size of the drum body. For example, a radius of, for example, 1cm, 1.5cm or 2cm may be used with an outer diameter of about 25cm, while a radius of 3cm, 5cm or 7cm may be used with an outer diameter of about 40 cm.

The orientation of the dimple 120 shown in fig. 1A-1C (or in the figures described below) is considered purely exemplary herein. In principle, any shape of the recess 120 is conceivable, for example a helical rotation with a constant or varying pitch. The only decisive factor for the concave shape or course is that it allows a simple control or regulation of the temperature control of the drum body 110 and that the pressure loss of the temperature control medium flow is kept as low as possible. This allows the cylinder body 110 and thus the extrusion cylinder 100 to be tempered in a simple manner without undue effort.

The recess 120 can be formed in the outer wall 115 of the drum body 110 in any manner suitable for this purpose. The recess 120 is preferably milled into the drum body 110. This allows a particularly simple production of the extrusion cylinder 100. However, the recess 120 may also be manufactured differently, for example by an etching process, by grinding, by casting a semi-finished product comprising the recess, etc.

The recess 120 of the extrusion cylinder 100 described with reference to fig. 1A to 1C defines the basic structure of a channel for guiding a temperature control medium. To form these channels, as schematically shown in fig. 2A, 2B and 3, a cover part 130 is connected to the outer wall 115 of the drum body 110, by means of which the recess 120 is sealingly closed. All cover parts 130 together leave only free inlets and outlets suitable for introducing a temperature control medium into the recess 120.

As shown in fig. 2A and 2B, those parts which are recessed, in particular those parts which are not arranged in the edge region 112 of the roller body 110, can be closed by a cover part 130 which is formed in the form of an inner recess 120. In particular, these sections of the recess 120 can be closed by correspondingly shaped, for example stamped metal sheets which are welded to the drum body 110 at the edges of the recess 120. However, other precisely fitting cover portions 130 are also contemplated, such as plastic caps. It is also possible to fasten the cover part 130 in other ways, for example by screwing, gluing or a combination thereof. If desired, a seal may be provided between the cover member 130 and the drum body 110 to provide a sealed passage for the temperature regulating medium.

As shown in fig. 3, those sections which are arranged recessed in the edge region 112 of the drum body 110 can be covered by connecting flanges 140 which are connected to the drum body 110, for example by press-fitting. By means of the press fit, these sections in the edge region 112 are sealingly closed. Furthermore, if the cover part 130 extends in the central region of the drum body 110 into the edge region 112, a sealed closure of the recess 120 can be achieved without further sealing.

This is shown in fig. 3 by way of example, in which the straight section 122 of the recess 120 is closed as shown in fig. 2A by a cover part 130, for example a welded sheet metal, while the curved section 124 is sealed by a connecting flange 140 which is arranged by means of a press fit. The connecting flange 140 also covers a part of the linear section 122. The closing recess 120 is thus realized in a simple manner.

Here, the connecting flanges 140 may be designed such that they enable a plurality of extrusion cylinders 100 to be combined to form one integral cylinder. However, these connection flanges may also form connection parts for connecting the extrusion cylinder 100 with the extrudate supply and discharge of the extrusion device in which the extrusion cylinder 100 is installed.

The supply and discharge portions may be disposed anywhere on the drum body 110 or through the connection flange 140. In order to supply the temperature control medium in the central region of the drum body 110, it is necessary for this purpose to leave a portion of the recess 120 open or to remove or drill the cover part 130 again in this position. This means a certain cost but allows a simple and free positioning of the supply point. In the case of supply via the connection flanges 140, these must have corresponding holes which, in the case of press fitting, lie above the desired free regions of the recess 120 in the edge region 112. If a corresponding connecting flange 140 is available, a temperature control medium supply can thereby be produced without further work steps.

Instead of the connecting flange 140 shown in fig. 3, the recess 120 can also be closed in the edge region 112 of the roller body 110 using, for example, a cover part 130 in the central region of the roller body 110. The closure is then performed in a uniform manner and independent of the use of the attachment flange 140.

Instead of covering the recess 120 with a precise fit, a covering part 130 can also be used which surrounds the entire roller body 110, as shown in fig. 4A and 4B. For example, a circular metal plate or tube can be pushed onto the roller body 110 by press fitting so that it then sealingly abuts against the roller body 110, so that the region of the recess 120 below the cover portion 130 is sealingly closed. As shown in fig. 4B, the cover portion 130 may expose the rim area 112 of the drum body 110. However, these edge regions can also be masked.

In fig. 5 to 7, a variant of the extrusion cylinder 100 is shown, in which a plurality of dimples 120 is present. The examples shown each have three non-communicating dimples 120. However, any number of dimples 120 is possible. The recess 120 surrounds a corresponding area of the drum body 110 like a sleeve. Therefore, the recesses completely surround a section of the drum body 110 in the circumferential direction of the drum body 110, and have a length less than the total length of the drum body 110. By means of such an inner recess 120, which in principle can also be designed differently from that shown in fig. 5 to 7, different temperature control circuits can be provided. As a result, the extrusion cylinder 100 may be divided into different temperature zones if needed to optimize the extrusion process. In particular, it is possible to produce indentations 120 and thus temperature zones that are not located in the edge region 112 of the drum body 110. It goes without saying that this division into different temperature zones can also take place in the circumferential direction. A plurality of recesses 120 are then required to circumferentially surround the drum body 110.

In an extrusion apparatus using one of the above-described extrusion cylinders 100, then, in order to regulate the temperature of each zone of the cylinder body 110 through which the dimples 120 pass, an own temperature regulating unit may be provided. This enables a completely free temperature regulation along the extrusion cylinder with a corresponding choice of the path of the recess 120, so that the quality of the extrudate can be increased.

As shown in fig. 5 to 7, the extrusion cylinder 100 can have a plurality of connection points 150, via which the tempering medium can be supplied and discharged. These attachment locations 150 are located at the beginning and end of the corresponding recesses 120 on the roller body 110. The remaining area of the recess 120 is closed by a cover part 130. As mentioned above, these cover parts can be designed with a precise fit (fig. 5 and 7), or-corresponding to the variant described with reference to fig. 4B-as a sleeve which completely surrounds the roller body 110 (fig. 6A and 6B, the sleeve shown here being transparent to show the recess 120 situated therebelow). In the first case, the connection locations 150 can simply be applied to the remaining free areas, for example welded, screwed or glued to the recesses. In the second case, the cover portion 130 is opened at the desired location and then the attachment location 150 is applied. When the extrusion cylinder 100 is closed by the connection flange 140, as shown in fig. 7, a partial supply may also be performed by the connection flange 140. By all these variants, the temperature control medium can be flexibly supplied as required.

As shown in fig. 3 and 7, the extrusion cylinder 100 may have a plurality of bores 160 penetrating completely through the hollow cylinder, i.e. establishing a connection between the interior space 118 of the cylinder body 110 and the outside. Pins, screws, bolts or the like can be inserted into such bores 160 until they project into the interior 118 and there act as additional friction points during operation to improve the plasticization and mixing of the extrudate. This occurs in a more efficient manner with the boreholes 160 distributed as evenly as possible.

Due to the free distribution of the dimples 120 resulting from the simple manufacturing process of these dimples 120 (e.g., by milling), the drill holes 160 may also be uniformly distributed along the drum body 110. Furthermore, the external production of the tempering medium channel allows a large section of the integral extrusion cylinder to be produced in one piece. When the apparatus for producing the dimples 120 is designed accordingly, it is also possible to produce the extrusion cylinder 100 which can be used as a total extrusion cylinder. This reduces the number of connecting flanges arranged over the length of the drum path. Since no bore holes 160 can be provided in the region of these flanges, by using the above-described extrusion cylinder 100, the number of bore holes 160, and thus the number of pins that promote plasticization and mixing of the extrudate, can be increased compared to conventional extrusion cylinders. This improves the quality of the extrudate.

The bore 160 is preferably not open in the region where the recess 120 extends, due to the easier accessibility. However, the dimple 120 and the bore 160 may also overlap. This is not a problem in principle if the pin inserted into the bore 160 is sealed off accordingly with respect to the temperature control medium. Thus, the bore holes 160 may in principle be completely freely distributed along the drum body 110.

Fig. 8 shows a schematic flow diagram of a method of producing one of the above-described extrusion cylinders. In a method step S810, which is of decisive significance for the production process, an indentation is provided in the outer wall of the extrusion drum, which is suitable for extruding, in particular rubber, and which, in the covered state, is suitable for guiding the temperature control medium. This is preferably achieved by milling the dimples in the housing of the hollow drum forming the extrusion drum. Optionally, the recess may then be covered at S820 by means of a cover part, preferably by welding or pressing a metal plate.

In this way, the tempering medium channel for tempering the extrusion cylinder can be introduced into the extrusion cylinder in a flexible, simple and error-free manner. Since the method is used from the outside, it is possible to produce extrusion cylinders having a greater length than is known from the prior art. This reduces the production and installation costs of an extrusion apparatus using such an extrusion cylinder. Furthermore, well-defined flow channels can be created for the tempering medium, which flow channels simplify and make it possible to flexibly temper the extrusion cylinder. Finally, due to the increase in length, the number of pins for plasticizing and mixing the extrudate guided in the extrusion cylinder can be increased, so that the quality of the extrudate can be improved.

List of reference numerals

100 extrusion roller

110 roller body

112 peripheral region of the drum body

115 outer wall of drum body

118 inner space of drum body

120 inner recess

122 straight section of the recess

124 concave curved section

130 cover part

140 connecting flange

150 connection location

160 drill hole