WO2017050811A1 - Device and method for processing thermoplastic plastic having an improved comminution/conveying device - Google Patents

Abstract

The invention relates to a device (1a..1i) for processing thermoplastic plastic which comprises a storage container (2) for receiving pieces of plastic particles or a conveying line (24) for conveying the pieces of plastic particles, and to a combined comminution/conveying device (3) connected to the storage container (2)/the conveying line (24). The device (1a..1i) also comprises an extruder (4) which connects to the combined comminution/conveying device (3). The combined comminution/conveying device (3) comprises a comminuting shaft (5) and a separately rotatable conveying screw (7), the comminuting shaft (5) having a higher comminuting effect per revolution than the conveying screw (7). An overlapping region (B) between the comminuting shaft (5) and the conveying screw (7) transversely to the axis of the comminuting shaft (5) is less than 75%. The invention also relates to a method for operating the device (1a..1i) in which the comminuting shaft (5) and the conveying screw (7) are rotated separately from one another and the plastic particles are comminuted to a larger degree by the comminuting shaft (5) than by the conveying screw (7).

Description

 Apparatus and method for processing thermoplastic with an improved shredder Z transport device

The invention relates to a device for processing of thermoplastic material, which comprises a reservoir for receiving piece-shaped plastic particles or a transport line for transporting piece-shaped plastic particles, one connected to the reservoir / the transport line to a transfer opening, combined crushing / transport device and a to the combined crushing / transport device subsequent extruder. In addition, the invention relates to a method for operating the above device.

An apparatus and a method of the above type are basically known from the prior art. For example, there are devices in which the combined crushing / transporting device comprising a crushing shaft and a screw conveyor, wherein the crushing shaft is arranged above the screw conveyor and the supplied via the reservoir or the transport line material passes through the shredding shaft transverse to its axis. The piece-shaped plastic particles fall from the crushing shaft down into the screw conveyor and are transported by this to the extruder. The disadvantage here is that the freeness of the plastic particles can not be practically adjusted because the plastic particles fall substantially after half a revolution of the blade shaft in the screw conveyor and be transported away from this.

On this subject, EP 0 934 144 Bl further discloses a device for processing thermoplastic material. The device comprises a machine housing with a feed hopper and a driven slide which presses the plastic material located on a base plate and to be processed into a conditioner drum or into a conveyor tube. On the conditioner drum, knives are screw-shaped. The knives and the subsequent conveyor screw feed the shredded plastic material to a screw of an extruder into which the plastic material is dispensed. The disadvantage of this is in particular that this device can be adjusted in operation only limited to different sizes of the supplied plastic particles. For example, the size of the particles can also be taken into account in the construction of the apparatus insofar as the conditioner drum, which is responsible for the comminution of the supplied material, is made longer for large plastic particles to be processed than for small particles. If, contrary to the original assumption, such a plant is later used for the processing of plastic particles for which it is not specified, plastic particles of a non-optimal size could be conveyed into the extruder.

In particular, if the plastic particles are too large, proper mixing and melting may not be ensured. If the plastic particles are cut smaller than necessary, then the conditioner drum is more heavily loaded than necessary and may need to be serviced sooner than necessary.

An object of the invention is therefore to provide an improved apparatus and an improved method for processing thermoplastic material. In particular, the extruder material of optimum size to be supplied, regardless of the size of the piece delivered to the device material.

The object of the invention is achieved with a device of the type mentioned, in which the combined crushing / transporting device comprises a crushing shaft and a separately rotatable screw conveyor, wherein the crushing shaft per revolution has a higher crushing effect than the screw conveyor and an overlap region between crushing shaft and Transport screw seen transversely to the axis of the crushing shaft (and seen in particular in the vertical direction) is less than 75% of the length of the crushing shaft.

The object of the invention is further achieved by a method for the operation of a device of the type mentioned, in which the crushing shaft and the screw conveyor are rotated separately, wherein the plastic particles in their passage through the combined crushing / transporting device of the crushing shaft be crushed more heavily than by the screw conveyor. By the proposed measures, the supply amount to the extruder and the particle size of the processed material can be set independently or controlled / regulated. The crushing shaft is mainly responsible for the crushing of the supplied plastic particles and the transport screw mainly for the transport of the supplied plastic particles. Thus, material of optimum size can be fed to the extruder, regardless of the size of the material delivered to the device. This ensures proper mixing and melting of the material and prevents clogging of the extruder. An unnecessary burden and wear of the crushing shaft can be avoided in this way. Due to the reduced coverage between crushing shaft and screw conveyor, the residence time of the plastic particles is extended in the crushing shaft and a dropping down into the screw conveyor after half a revolution of the blade shaft is at least partially prevented.

A lower coverage promotes this effect. Further advantageous values for the mentioned coverage are therefore <50% and <25%. It is particularly advantageous if the comminution shaft, viewed transversely to the axis of the comminution shaft (and in particular in the vertical direction), is at all free of overlap with the transport screw. In other words, the crushing shaft and the screw conveyor are then arranged side by side, whereby the residence time of the plastic particles in the crushing shaft is particularly large.

In the above context, it is furthermore particularly advantageous if the comminution shaft is aligned coaxially or substantially coaxially with the transport screw. In this way, a favorable material flow and also a simple construction of the disclosed device result. The drive of the crushing shaft and the screw conveyor can for example be done from two sides or from one side via a hollow shaft. "Substantially coaxial" in this context means in particular an angle deviation of the two shaft axes of <10 ° or a shaft offset of <10% of the largest diameter of the comminution shaft. In principle, a minimum value for the overlap between the comminution shaft and the transport screw can also be provided, for example an overlap of> 25% or even> 50%. Therefore, advantageous ranges for said coverage are from 25% to 75% or even from 50% to 75%. In particular, with non-coaxial arrangement of crushing shaft and screw conveyor so leads a minimum cross section for the material transfer from the crushing shaft in the screw conveyor, which is less prone to clogging.

In summary, what has been said results from a variant a) in which the axes of the two shafts are spaced apart from one another or aligned parallel to one another, with an overlap area of <75%, and a variant b) in which the comminution shaft and the transport screw are substantially coaxially aligned and do not overlap each other, that is, an overlap range of 0% is present.

The comminution effect can be related in particular to the ratios of the mean size of the plastic particles entering the comminution shaft / transport screw to their average size at the exit from the comminution shaft / transport screw, larger ratios characterizing a higher comminution effect. Specifically, the size of a plastic particle may be related to its surface and / or volume and / or weight. Because of the higher crushing effect of the crushing shaft, the ratio of the average size of the plastic particles entering the crushing shaft to the mean size at the outlet of the crushing shaft is greater than the ratio of the average size of the plastic particles entering the screw conveyor to the mean size at the exit from the screw conveyor.

For example, a square plastic film made of PP (polypropylene) with a side length of 200 mm and a thickness of 0.1 mm can be used as the reference material for determining the different comminution action by the comminution shaft and the transport screw. If the presented device is filled with a piece or several pieces of the reference material, this is comminuted more strongly by the comminution shaft than by the transport screw. For the comminution of the plastic particles, the comminution shaft can have comminution means arranged thereon, which are formed in particular by teeth and / or by continuous cutting edges and / or by knives. The crushing shaft can be continuously filled with cutting edges and / or teeth and / or knives, or these only in a (continuous) portion (ie in a crushing area), which adjacent to an initial area and / or end, in which / no cutting , Teeth or knives are arranged. On a crushing shaft continuous cutting edges, teeth and blades can be used alone or in any combination.

"Through cutting" extend substantially over the entire length of the crushing shaft or over the entire length of a crushing region. In particular, the continuous cutting can be spiral or axial. A plurality of continuous cutting edges can be distributed over the circumference of the comminuting shaft, or the comminuting shaft has only one continuous cutting edge. During the rotation of the comminution shaft, the continuous cutting edges are moved substantially transversely to their longitudinal extension, respectively the rotation of the comminuting shaft causes a movement with such a transverse component. The separation of the plastic particles therefore takes place mainly by shearing.

"Teeth" can be interpreted as interrupted cutting or cutting with gaps. Their cutting edges can also run in a spiral or in an axial direction and also their cutting edges are moved transversely to their longitudinal extent during the rotation of the comminuting shaft. The separation of the plastic particles is therefore mainly by shearing and tearing.

"Knives" do not have a pronounced axial extent, and their cutting edges extend substantially radially outwardly. During the rotation of the comminution shaft, the cutters are again moved transversely to their longitudinal extension, but the plane of the "knife back" is essentially normal to the axis of rotation of the comminution shaft. The separation of the plastic particles is done mainly by cutting. In general, an exact subdivision of the separation process is hardly possible, especially if the cutting edges are not exactly aligned axially or not exactly radially. In general, the plastic particles are therefore comminuted by shearing and tearing and cutting. For the concentration of the comminution action on the comminution shaft, it can be advantageously provided that the transport screw has fewer comminution means than the comminution shaft. In particular, it is advantageous if the transport screw is at all free of comminuting agents. For example, the transport screw may have rounded edges, whereby the subsidized plastic particles (in a manner not intended in itself) are further crushed by crimping at best.

Further advantageous embodiments and modifications of the invention will become apparent from the dependent claims and from the description in conjunction with the figures. It is favorable if, in the area of the comminution shaft with its continuous cutting edges / knives / teeth (in particular in their comminuting area), cooperating, fixed counterblades / counterblades / counter teeth are arranged. This improves the cutting performance of the shredding shaft. In particular, when providing knives and counter knives, the separation of the plastic particles is no longer necessarily mainly by cutting, but possibly also by shearing.

It is also advantageous if the screw conveyor is closer to the extruder and the crushing shaft is closer to the container / transport tube. It is also advantageous in this connection if the comminution shaft of the transport screw is arranged upstream in the transport direction of the plastic and is arranged in the storage container / in the transport line or at least projects into it. As a result, a specific piece size of the processed plastic particles is first determined with the aid of the comminution shaft and, with the help of the transport screw, a certain amount of material is transported on to the extruder.

But it is also advantageous if the screw conveyor closer to the container / transport tube and the crushing shaft is closer to the extruder or that the crushing shaft of the screw conveyor is downstream in the transport direction of the plastic. As a result, with the help of the screw conveyor a certain amount of material is transported to the crushing shaft, which then produces a certain piece size of the processed plastic particles. In addition, it is favorable if the comminution shaft and the screw conveyor are accommodated in a common housing. In this way, a simple construction of the disclosed device results.

It is also favorable if the transport screw and the extruder have a common shaft or are arranged on a common shaft. This results in a simple construction of the disclosed device and an advantageous material flow.

It is also advantageous if the crushing shaft has screw-like means of transport. In this way, the crushed by the crushing shaft material is also transported in the axial direction, whereby the material flow to the screw conveyor is further improved. The crushing shaft may in this case also be called "shredder screw" or be taken as such. It is also advantageous if the crushing shaft and the screw conveyor are rotated simultaneously at different speeds. In this way, material is continuously fed into the extruder. In particular, the crushing shaft can be rotated at a higher speed than the screw conveyor, to concentrate the crushing effect even more on the crushing shaft. If the comminution shaft and the screw conveyor are operated at different rotational speeds, their helical transport means can also have different inclinations in particular.

It is particularly advantageous if a speed of the crushing shaft is increased relative to a rotational speed of the screw conveyor, if a lying above a target size size of the subsidized plastic particles is detected and vice versa. Thereby, the plastic particles are finely divided when a larger than a target size size of the conveyed plastic particles is detected, and lowered the degree of grinding when a below a target size lying size of the subsidized plastic particles is detected. It should be noted at this point that the variants disclosed to the device for processing thermoplastic material and the advantages resulting therefrom also apply mutatis mutandis to the embodiments of the operating method according to the invention and vice versa.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

In each case, in a highly simplified, schematic representation:

Figure 1 shows a first exemplary and schematically illustrated apparatus for processing of thermoplastic material, wherein the crushing shaft is arranged offset to the transport screw.

Fig. 2 similar to the device shown in Figure 1, but with coaxial arrangement of crushing shaft and screw conveyor.

3 shows a further exemplary and schematically illustrated apparatus for processing thermoplastic material with a comminuting shaft / worm with teeth;

Fig. 4 as Figure 3, with only one sensor for determining a particle size, as well as with rotating knives.

Figure 5 as Figure 4, only with additional rotating teeth ..;

6 shows an exemplary and schematically illustrated device with a distribution gear for driving the shredding shaft / worm and the screw conveyor from one side;

7 shows an exemplary and schematically illustrated device with a shredding shaft / worm with continuous cutting edges; FIG. 8 is similar to FIG. 3, but with the order of the comminution shaft / screw and transport screw reversed, and FIG. 9 shows an exemplary and schematically illustrated device with a transport tube instead of the container for the plastic particles.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component designations, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and to transmit mutatis mutandis to the new situation in a change in position.

Fig. 1 shows a schematically illustrated device la for processing of thermoplastic material, which comprises a reservoir 2 for receiving piece-shaped plastic particles, and connected to the reservoir 2 at a transfer opening A, combined crushing / transport device 3 and one to the combined crushing - / Transport device 3 subsequent extruder. 4

The combined comminution / transport device 3 comprises a comminution shaft 5 and a transport screw 7 rotatable separately therefrom, the comminution shaft 5 having a higher comminuting effect per revolution than the transport screw 7. Concretely, the combined comminution / transport device 3 comprises a comminution shaft 5 with radial arranged knives 6 and one of them separately rotatable toothless screw conveyor 7th

The comminution shaft 5 is driven by a first drive motor 8, the transport screw 7 is driven by a second drive motor 9, and the extruder 4 is driven by a third drive motor 10. The screw conveyor 7 and the extruder 4 cross each other in the example shown. It should be noted, however, that in Fig. 1 at is a purely schematic representation and the screw conveyor 7 and the extruder 4 may be arranged differently to each other, in particular coaxially.

In the example shown, the axes of the comminution shaft 5 and the transporting screw 7 are arranged parallel to each other. It is also conceivable, however, that the comminuting shaft 5 and the transporting screw 7 intersect each other, as is the case in FIG. 1 for the transporting screw 7 and the extruder 4.

Furthermore, the crushing shaft 5 and the screw conveyor 7 are housed in a common housing, which is also advantageous, but not mandatory. Rather, it is also conceivable that the crushing shaft 5 and the screw conveyor 7 are housed in separate housings.

During operation of the apparatus la, the comminuting shaft 5 and the transporting propeller 7 are rotated separately from one another. In the concrete example, this is done via the two motors 8 and 9. With the help of the two motors 8 and 9, the crushing shaft 5 and the screw conveyor 7 can be rotated almost completely independently. For this purpose, the device la also includes an optional controller 11, which allows separate control of the motors 8 and 9. For example, the material filled in the container 2 can be analyzed and, based on the analysis result, a rotational speed for the comminuting shaft 5 and the transporting screw 7 can be selected.

In principle, it would also be possible for the comminuting shaft 5 and the transporting screw 7 to be driven by a single motor, the driving force of which is distributed via a transmission (see also FIG. 6). In a transmission with a rigid translation, the comminution shaft 5 and the screw conveyor 7 may be rotated at different speeds, but in a rigid relationship to each other. However, it would also be conceivable to use variable-ratio gearboxes or controllable torque converters, which enable a completely independent rotation even with a single motor. Advantageously, the crushing shaft 5 and the screw conveyor 7 are simultaneously rotated at different speeds in order to effect a continuous delivery of the plastic particles. In principle, however, the (at least temporarily) intermittent operation of the comminution shaft 5 and the transport screw 7 would be conceivable.

In FIG. 1, the comminution shaft 5 is arranged above the transport screw 7 and laterally slightly offset therefrom. Concretely, an intersection region B between crushing shaft 5 and screw conveyor 7 transverse to the axis of the crushing shaft 5 in this example, 50% of the length of the crushing shaft 5. In this way, a long residence time of the plastic particles in the crushing shaft 5 can be achieved before this in the Fall down transport screw 7. The value 50% can be seen as an example and other values are also conceivable, smaller overlap areas favoring a longer residence time of the plastic particles in the area of the comminution shaft 5.

Advantageous ranges for said coverage are between 25% and 75% or even between 50% and 75%. In this way, a minimum cross section for the material transfer from the comminution shaft 5 into the transport screw 7, which is less prone to blockages.

In the example shown in Fig. 1, the crushing shaft 5 has no screw-like transport means. Of course, these may be present (see also Fig. 3 to 10). In general, the provision of helical transport means on the comminution shaft 5 is rather advantageous in the case of smaller overlap areas B, rather unnecessary for larger overlapping areas B.

In principle, the promotion of the plastic particles in the transport screw 7 can also be supported by optional air nozzles, which are aligned in the conveying direction of the plastic particles. FIG. 1 shows an exemplary embodiment in which a compressor 12 conveys compressed air into a compressed-air tank 13, from which it flows out of the nozzles 15 and 16 via a valve 14 and blows the plastic particles in the direction of the transport screw 7. Of course, air nozzles 15, 16 are fully applicable even in the examples shown in Figures 2 to 10. The example shown in FIG. 1 shows a variant a), in which the axes of the comminuting shaft 5 and the transporting screw 7 are spaced from one another or are aligned parallel to one another, with an overlapping range of <75%.

Also conceivable is a variant b), in which the comminution shaft 5 and the screw conveyor 7 are aligned substantially coaxially (and next to each other) and do not overlap one another, ie an overlap region transverse to the axis of the comminution shaft 5 is 0%. In this way, the residence time of the plastic particles in the comminution shaft 5 is particularly long.

FIG. 2 shows an exemplary device 1b, which is similar to the device 1a shown in FIG. In contrast, the comminution shaft 5 is aligned coaxially with the transport screw 7. Also in this embodiment, the residence time of the plastic particles in the area of the comminution shaft 5 is comparatively large. In order to promote the promotion of plastic particles in the screw conveyor 7, again compressed air-operated nozzles 15, 16 may be provided, as is the case in the example shown in FIG. 1. Although the coaxial alignment of the shredder screw 5 and the screw conveyor 7 is favorable in terms of material flow, but not mandatory. Rather, it is also conceivable that the comminution shaft 5 and the screw conveyor 7 intersect each other, similar to the case in FIG. 1 for the transport screw 7 and the extruder 4. FIG. 3 shows a further exemplary and diagrammatically illustrated device 1c for processing thermoplastic material, which is similar to the device 1b shown in FIG. In contrast, however, the crushing shaft 5 has screw-like means of transport and is therefore referred to below as "crushing screw". By the screw or helical transport the material transport to the screw conveyor 7 is improved. In addition, the crushing shaft / worm 5 has teeth 17 instead of the knives 6. Furthermore, the combined comminution / Transport device 3 in the field of crushing screw 5 optional, cooperating with the teeth 17 of the shredder screw 5, fixed counter teeth 18, through which the cutting performance of the shredder screw 5 is improved. As can be seen from FIG. 3, 5 teeth 17 and counter teeth 18 are arranged only in a central region of the comminution shaft / screw, whereas the beginning and end regions run as a continuous screw. This is advantageous insofar as the continuous starting part promotes the conveyance of the plastic particles into the comminuting / transporting device 3 and the continuous end region promotes the conveyance into the transporting screw 7. However, this embodiment is not mandatory. Rather, it is also conceivable that the crushing screw 5 has only one continuous starting region or only a continuous end region or full length with teeth 17 is occupied. It is also conceivable that the counter-teeth 18 are arranged opposite to the illustration in FIG. 1 offset from the teeth 17 of the shredder screw 5. Shearing of the plastic particles then takes place (also) on the side flanks of the teeth 17 / counter teeth 18.

In a further advantageous variant, a rotational speed of the shredder screw 5 is increased in relation to a rotational speed of the screw conveyor 7, if a size of the conveyed plastic particles lying above a desired size is determined, and vice versa. FIG. 4 shows an example in the form of a device ld, which is very similar to the device 1c shown in FIG. In contrast, however, a sensor 19 is provided for determining a particle size of the conveyed into the screw conveyor 7 plastic particles and connected to the controller 11. For example, this can operate on the optical principle. The sensor 19 may be formed for example by a camera. If a size of the conveyed plastic particles lying above a desired size is then determined, then a rotational speed of the comminution screw 5 is increased in relation to a rotational speed of the transport screw 7, and the plastic particles are divided finer. Conversely, the freeness is lowered when a size of the conveyed plastic particles below a target size is determined.

Moreover, in the example shown in FIG. 4, instead of teeth 17 and counter teeth 18, knives 6 and counter knives 20 are provided, which are arranged in the end region of the comminuting screw 5. FIG. 5 shows a further example in the form of a device le which is very similar to the device 1d shown in FIG. In addition to the knives 6 and counter knives 20, teeth 17 and counter teeth 18 are now also provided, the teeth 17 and teeth 18 being arranged in the front area of the shredding screw 5 and the knives 6 and counter knives 20 in the end area of the shredding screw 5.

By the feedback by means of the sensors 19 in Figures 4 and 5, the piece size of the plastic particles can not only be controlled, but also regulated.

Fig. 6 shows a further embodiment of a device le, in which the crushing screw 5 and the screw conveyor 7 are driven from one side. For this purpose, the shaft of the screw conveyor 7 is formed as a hollow shaft, and the shaft of the crushing screw 5 is passed through said hollow shaft (shown in dashed lines in FIG. 6). With the aid of a gear 21, the two shafts are coupled to the motors 8 and 9. It would also be conceivable to use a single motor, in particular in conjunction with a planetary gear. With the help of a planetary gear, the driving force of the motor can be distributed in a particularly elegant manner to the two coaxial shafts. If the planetary gear is designed switchable, so even when using only one motor in operation different speed ratios between the crushing screw 5 and the screw conveyor 7 can be realized. In particular, the planetary gear can also be executed in multiple stages.

In Fig. 6, the shaft of the screw conveyor 7 is designed as a hollow shaft. Of course, it would also be conceivable that the shaft of the shredder screw 5 is designed as a hollow shaft and the shaft of the screw conveyor 7 is passed through the hollow shaft. In this case, the transmission 21 and the motors 8 and 9 would be arranged on the left.

FIG. 7 shows a further example of a device lg for processing thermoplastic material. In this variant, the crushing screw 5 no teeth 17 and no knives 6, but continuous cutting 22. These blades 22 cooperate with fixed cutting edges 23, whereby the supplied material is also crushed. The screw conveyor 7, however, is free of cutting. The fixed cutting edges 23 may be formed, for example, as axially aligned cutting edges (see also the front view C) or else also run in a spiral shape (see the front view D). It is particularly advantageous if the pitch of the fixed spiral-shaped cutting edges 23 is different from the cutting edges 22 of the grinding screw 5, since then load peaks in the drive torque are avoided. The spiral-shaped sheaths 23 can be wound in the same sense as the cutting edges 22 of the comminuting screw 5 or also in opposite directions. Finally, it would also be conceivable that the fixed cutting edges 23 are normal to the axis of the crushing screw 5.

In general, it is advantageous if the fixed cutting edges 23 are arranged only in the upper and in the lateral area of the comminuting screw 5, since in this way it is avoided that material accumulates in the lower region of the comminuting screw 5, which is not transported away. In addition, the tube in which the crushing screw 5 is arranged, funnel-shaped together, whereby the collection of plastic particles is promoted in the crushing screw 5. Of course, said eccentric configuration and / or said funnel-shaped structure is also suitable for the teeth 17 and knife 6 shown in FIGS. 3 to 5. Conversely, for the cutting edges 23 of FIG. 7, a coaxial and / or cylindrical arrangement possible. Finally, it is also conceivable that the shredder worm 5 has cutting edges 22, knives 6 and teeth 17.

In the previous examples it was assumed that the transport screw 7 is closer to the extruder 4 and the shredder screw 5 is closer to the container 2. Although this is advantageous, as determined in this way with the help of the shredder screw 5, first a certain piece size of the processed plastic particles and thereof with the help of the screw conveyor 7, a certain amount of material is transported to the extruder 4. But this is not mandatory.

Rather, it is also conceivable that the transport screw 7 is closer to the container 2 and the shredder screw 5 is closer to the extruder 4, as shown in FIG. 8 for the Vorrich- lh is shown. As a result, a certain amount of material is transported to the shredder screw 5 with the help of the screw conveyor 7, which then produces a certain piece size of the processed plastic particles. In addition, in FIG. 8, the comminuting screw 5 is equipped with teeth 17, for example, over its full length.

Fig. 9 also shows an example in which instead of the container 2, a transport tube 24 is provided. Via the transport tube 24, plastic particles are transported not only to the combined crushing / transporting device 3 but also to other units (not shown). In particular, the transport direction is from top to bottom. As a result of the movement of the plastic particles and the comminution / transport device 3 protruding into the transport pipe 24, some of the material transported in the transport pipe 24 can be diverted and conveyed into the comminuting / transporting device 3.

In general, the comminuting shafts 5 illustrated in FIGS. 3 to 9, such as the comminution shaft 5 of FIG. 2, can also be formed without helical transport means, since the plastic particles basically also reach the transport helix 7 after a certain time.

In the previous examples it was assumed that the comminution shaft / worm 5 and the transport worm 7 are (exactly) aligned coaxially. In principle, it is also possible without serious deterioration of the properties of the devices la. Lg, the comminution shaft / worm 5 and the screw conveyor 7 to align substantially coaxially. In particular, an angular deviation of the two shaft axes of <10 ° or a shaft offset of <10% of the largest diameter of the comminuting shaft / worm 5 is conceivable in this connection.

In the examples shown so far, the screw conveyor 7 in the horizontal direction and the transfer opening A is also aligned in the horizontal direction. This is advantageous, but not mandatory. It is also generally conceivable that the transport screw 7 and / or the cross section of the transfer opening A are aligned obliquely or even vertically. By the proposed measures, in general, the supply amount to the extruder 4 and the particle size of the processed material can be set independently. Thus, the extruder 4 material can be supplied of optimum size, regardless of the size of the piece delivered to the device la..li material. This ensures proper mixing and melting of the material and clogging of the extruder 4 can be avoided. An unnecessary burden and wear of the crushing shaft / worm 5 can be avoided in this way.

In general, it should be noted that the crushing shaft / worm 5 mainly crushes and the conveying screw 7 mainly transported. However, a complete separation of the two functions is not entirely possible, which is why the transport screw 7 also divided and the shredder screw 5 also promotes, although each has a different task in the foreground. In general, the function of a transport screw 7 is mainly the material transport and less the heating of the transported material. In the extruder 4, however, a significant material heating (namely beyond the melting point of the plastic particles out) is desired. However, these two functions can hardly be completely separated. The crushing effect may in particular on the ratios of the average size of the

Plastic particles when entering the crushing shaft / worm 5 / screw conveyor 7 to the mean size at the outlet of the crushing shaft / worm 5 / screw conveyor 7 be related, with larger ratios characterize a higher crushing effect. In particular, the size of a plastic particle may be based on its surface area and / or its volume. Because of the higher crushing action of the crushing shaft / worm 5, the ratio of the average size of the plastic particles entering the crushing shaft / screw 5 to the mean size at the exit from the crushing shaft / screw 5 is larger than the ratio of the average size of the plastic particles Entry into the screw conveyor 7 to the mean size at the exit from the screw conveyor 7th For the determination of the different comminution effect by the comminution shaft / screw 5 and the transport screw? For example, a square plastic film made of PP (polypropylene) with a side length of 200 mm and a thickness of 0.1 mm can be used as the reference material. The device la .. li is to be filled with a piece or several pieces of the reference material.

In the above examples, a greater comminution action of the comminuting shaft / worm 5 arises solely from the fact that the comminuting shaft / worm 5 there are comminution means arranged thereon in the form of teeth 17 and / or in the form of continuous cutters 22 and / or in the form of knives 6 and the screw conveyor 7 has fewer comminuting means 6, 17, 22 than the comminution shaft / screw 5 or at all free of comminuting means 6, 17, 22. In the latter case, the edges of the screw conveyor 7 may be rounded, for example. In principle, however, the screw conveyor 7 may also have comminuting means, as long as their comminuting action remains smaller than that of the comminution shaft / screw 5.

However, a higher comminution action of the comminution shaft 8 relative to the transport screw 7 can also be realized or assisted by rotating the comminuting shaft / screw 5 at a higher speed than the transport screw 7. In this case, the comminuting shaft / screw 5 and the Transport screw 7 also have the same crushing effect per revolution and in particular be identically constructed.

The embodiments show possible embodiments of a device la .. li for processing of thermoplastic material and method for their operation, it being noted at this point that the invention is not limited to the specifically illustrated embodiments of the same or the same, but rather also various combinations The individual variants are possible with each other and this possibility of variation is due to the teaching of technical action by objective invention in the skill of those working in this technical field expert. Thus, all conceivable embodiments are possible, which arise through combinations of individual details of the illustrated and described embodiments. For example, a crusher shaft 5 according to FIG. 3 can also be used in the example illustrated in FIG. 9. Also, the eccentric structure and / or funnel structure shown in Fig. 7 can be applied to the other examples. In general, the order of the crushing shaft / worm 5 and the screw conveyor 7 can be reversed in all examples. The use of a gear 21 instead of both sides arranged motors 8 and 9 is generally possible. In addition, the arbitrary use of teeth 17 / counter teeth 18, knives 6 / counter knives 20 and cutting edge 22 / counter cutting 23 in all examples arbitrarily possible in combination. Finally, the use of a transport tube 24 instead of a container 2 and vice versa is possible. Of course, the use of the sensor 19 and thus also a control of the particle size in the examples shown in FIGS. 1 and 2 without any restrictions is possible.

In particular, it is noted that a device la .. li in reality may also include more or fewer components than shown.

For the sake of order, it should finally be pointed out that for a better understanding of the structure of the device la..li these or their components were shown partially uneven and / or enlarged and / or reduced. The task underlying the independent inventive solutions can be taken from the description.

REFERENCE NUMBERS

1 a..1 i Device for processing thermoplastic material

2 storage tanks

 3 combined crushing / transport device

 4 extruders

 5 crusher shaft

6 knives (on comminution shaft)

 7 transport screw

 8 first drive (for comminution shaft)

 9 second drive (for transport screw)

 10 third drive (for extruder)

11 control / regulation

 12 compressors

 13 pressure tank

 14 valve

 15 nozzle

16 nozzle

 17 teeth (on comminution shaft)

 18 fixed teeth

 19 Sensor for determining a particle size

 20 counter knives

21 gears

 22 cutting (on shredder screw)

 23 fixed cutting edges

 24 transport tube

A transfer opening

B Intersecting section Crushing shaft / screw conveyor

Claims

Patent claims 1. Device (la .. Ii) for processing of thermoplastic material, comprising  a storage container (2) for receiving piece-shaped plastic particles or a transport line (24) for transporting piece-shaped plastic particles,  one combined with the reservoir (2) / the transport line (24) at a transfer opening (A), combined crushing / transport device (3) and  an extruder (4) adjoining the combined comminution / transport device (3) and rotatable separately therefrom, characterized in that  the combined comminution / transport device (3) comprises a comminution shaft (5) and a feed screw (7) which is rotatable separately therefrom, the comminution shaft (5) having a higher comminuting action per revolution than the transport screw (7) and  an overlapping area (B) between the comminution shaft (5) and the transport screw (7) transversely to the axis of the comminution shaft (5) is less than 75% of the length of the comminution shaft (5). 2. Device (la .. Ii) according to claim 1, characterized in that the crushing effect on the ratios of the average size of the plastic particles when entering the crushing shaft (5) / screw conveyor (7) to the mean size at the exit from the crushing shaft ( 5) / transport screw (7) is related and larger conditions characterize a higher crushing effect. 3. Device (la..li) according to claim 2, characterized in that the size of a plastic particle is based on the surface and / or its volume and / or its weight. 4. Device (la .. Ii) according to one of claims 1 to 3, characterized in that the crushing shaft (5) viewed transversely to the axis of the crushing shaft (5) without overlap with the transport screw (7). 5. Device (la .. li) according to one of claims 1 to 3, characterized in that the crushing shaft (5) with the screw conveyor (7) is aligned substantially coaxially. 6. Device (la .. li) according to one of claims 1 to 5, characterized in that the crushing shaft (5) thereon arranged crushing means (6, 17, 22). 7. Device (la..li) according to claim 6, characterized in that the transport screw (7) less shredding means (6, 17, 22) than the crushing shaft (5). 8. Device (la .. Ii) according to claim 6 or 7, characterized in that the comminution means by teeth (17) and / or knives (6) and / or continuous cutting edges (22) are formed. 9. Device (la .. Ii) according to one of claims 6 to 8, characterized in that in the region of the comminution shaft (5) with its teeth (17) / knives (6) / continuous cutting (22) cooperating, fixed counter teeth ( 18) / counter-knife (20) / counter-cutting edges (23) are arranged. 10. Device (la .. Ii) according to one of claims 1 to 9, characterized in that the transport screw (7) is free of crushing means (6, 17, 23). 11. Device (la .. Ii) according to one of claims 1 to 10, characterized in that the crushing shaft (5) of the screw conveyor (7) is upstream in the transport direction of the plastic. 12. Device (la .. Ii) according to claim 11, characterized in that the comminution shaft (5) in the reservoir (2) / in the transport line (20) is arranged or at least projects into this / these. 13. Device (la .. li) according to one of claims 1 to 10, characterized in that the crushing shaft (5) of the screw conveyor (7) is downstream in the transport direction of the plastic. 14. Device (la .. li) according to one of claims 1 to 13, characterized in that the crushing shaft (5) and the screw conveyor (7) are housed in a common housing. 15. Device (la .. li) according to one of claims 1 to 14, characterized in that comminution shaft (5) has screw-like transport means. 16. A method for processing thermoplastic material by means of a device (la .. li), which a storage container (2) for receiving piece-shaped plastic particles or a transport line (24) for transporting piece-shaped Kunststoffteil- Chen, one with the reservoir (2). / the transport line (24) at a transfer opening (A) connected, combined crushing / transport device (3) and to the combined crushing / transport device (3) subsequent and separately rotatable extruder (4), characterized in that the crushing shaft (5) and the screw conveyor (7) are rotated separately from each other, wherein the plastic particles are crushed by the comminution shaft (5) as they pass through the combined crushing / transporting device (3) from the crushing shaft (5) than from the screw conveyor (7). 17. The method according to claim 16, characterized in that the ratio of the average size of the plastic particles when entering the crushing shaft (5) to its average size at the outlet from the crushing shaft (5) is greater than the ratio of the average size of the plastic particles at the entrance in the screw conveyor (7) to the mean size at the exit from the screw conveyor (7). 18. The method according to claim 17, characterized in that the size of a Plastic particle on the surface and / or its volume and / or its weight is related. 19. A method according to any one of claims 16 to 18, characterized in that the crushing shaft (5) and the screw conveyor (7) are rotated simultaneously at different speeds. 20. The method according to claim 19, characterized in that a speed of the crushing shaft (5) relative to a rotational speed of the screw conveyor (7) is increased when a lying above a target size size of the subsidized plastic particles is detected and vice versa.