WO2010040474A1

WO2010040474A1 - Compacting system for foamed plastic material

Info

Publication number: WO2010040474A1
Application number: PCT/EP2009/007055
Authority: WO
Inventors: Jürgen HEGER
Original assignee: Heger Gmbh + Co. Kg
Priority date: 2008-10-08
Filing date: 2009-10-01
Publication date: 2010-04-15
Also published as: DE202008013388U1

Abstract

The invention relates to a compacting system for foamed thermoplastic plastic material. The compacting system comprises a compactor (1) and a pressure channel (2) connected downstream of the compactor (1) for forming a pressed plastic body (3). The pressure channel (2) is provided with a melting device (4) for melting at least a part of the surface of the pressed plastic body (3).

Description

Compaction system for foamed plastic material

The invention relates to a compression system for foamed plastic material of the type specified in the preamble of claim 1.

Foamed plastics are used in large quantities for a variety of applications. In addition to being used as thermally insulating insulation material, it is used on a large scale as a shock-proof packaging for sensitive goods. In particular, in the latter application, the temporal use is limited, followed by the foamed plastic packaging material is waste.

Such waste is problematic in terms of disposal, as a result of large amounts of waste due to the foaming and the low density. The collection, for example, in containers is costly because of the large volume. Recycling is technically possible, but economically hardly feasible because of the low density.

Nevertheless, in order to make foamed plastic materials available for economic recycling or economical disposal, increasingly compression systems are used which comprise a compressor and a downstream pressure channel for forming a plastic compact. The compressor compresses the pores of the foamed plastic material, which considerably reduces the accumulated volume. at suitable design space weights can be achieved, which are close to that of the same, but not foamed plastic material. The compacted plastic material is forced through the downstream pressure channel, creating a substantially rod-shaped, highly compacted plastic compact. This can be cut to length and then easily stored, transported and economically recycled or disposed of.

Such an arrangement has been proven in foamed plastic materials such as expanded polystyrene (EPS). The typical cell shape of the EPS allows easy compaction. In conjunction with the pronounced brittleness of the base material, the compression is maintained even after removal of the external pressure. The plastic fragments compressed to press sufficiently adhere to each other, so that a manageable, possibly also stackable plastic compact arises.

However, especially in the packaging sector, other foamed plastics such as expanded polypropylene (EPP) or expanded polyethylene (EPE) are increasingly being used. These or similar materials are much more elastic compared to the EPS and also form a smooth surface with low tendency to stick. This means that the previously crushed expanded plastic material can be compressed as well as EPS. However, the crushed compacted fragments do not sufficiently adhere to each other within the formed plastic compact. After the supporting effect of the pressure channel is no longer present, the decays Plastic compact and therefore can not be processed into stackable blocks. In addition, the high elasticity of the materials mentioned leads to the fact that the compressed state is at least partially lost after elimination of the pressing pressure. This effect is still manageable with EPP. In the case of EPE or other comparable plastics, the plastic compact automatically inflates again after the pressing process to a volume which makes the previously performed pressing virtually useless. According to the known state of the art, no compression system is currently known which can form foamed plastic materials such as EPP or EPE into an economically processable plastic compact.

The invention has the object of developing a generic compression system such that foamed plastic materials can be compacted in a greater variety of materials for economic processing.

This object is achieved by a compression system having the features of claim 1.

For this purpose, it is proposed that the pressure channel downstream of the compressor is provided with a melting device for melting at least part of the surface of the plastic compact. When passing through the plastic compact through the pressure channel at least a portion of its surface is melted. After the melted surface has cooled and solidified, a mechanically resilient skin is formed which combines the shredded and compacted fragments within the plastic compact. holds. In addition, the solidified skin prevents elastic expansion of the plastic material. The plastic compact keeps at least approximately its compacted shape after the elimination of the pressing pressure.

The invention is based on the idea that it is not necessary for a reliable retention of the pressed mold to fuse the pressed material as a whole. Rather, an external skin formation is sufficient to achieve the desired effect. The required heating and energy costs are low. Thermal damage to the plastic material is avoided, so that recycling is readily possible. The resulting plastic compact is easily processed. By forming the plastic compact as a continuous material, individual stackable blocks can be easily formed by cutting the outer molten skin. The inner material does not adhere or not significantly to each other, so that individual blocks can be separated from each other without difficulty. The compacted plastic material processed into rods or blocks can be stacked and transported on pallets, for example, so that low storage and transport costs are incurred. Since only one outer skin has melted and solidified, further processing for a recycling procedure is possible without problems. Overall, the arrangement of the invention allows an economic compression and processing of expanded thermoplastic materials with almost any variety of materials.

Depending on the adhesive behavior and expansion tendency of the processed foamed plastic material, it may suffice to melt the surface of the plastic blank not completely, but only partially. Suitably, the melting device acts on at least 50% and preferably at least 70% of the circumference of the plastic compact. In particular, in plastics with a high tendency to elastic recoil and low adhesion tendency but also higher surface proportions up to 100% may be appropriate. The result is a mechanically integral plastic compact that can be further processed economically in the manner described above.

For the melting device different heating systems come into consideration. Infrared heaters or mechanical heaters such as ultrasonic heaters may be provided. In a preferred embodiment, the melting device comprises at least one heating plate. The heating plate transmits its heat to the plastic compact by means of surface contact. It has been found that this allows a clean temperature control even under less than optimal conditions. Surface burns will remain off even during a short machine downtime. The quality of the pressed plastic material is retained, which benefits the recycling value.

In a preferred development, at least one first heating plate and at least one second heating plate are provided, wherein the at least one second heating plate is arranged at a distance behind the at least one heating plate, wherein the circumference of the pressure channel in the region of the respective first and second heating plate is not completely by at least a first heating plate or by the at least one second heating plate is covered, and wherein the at least one first heating plate and the at least one second heating plate lie in different peripheral sections of the pressure channel. This arrangement is based on the finding that the frictional resistance of the plastic compact is lost in the pressure channel by the melting of the surface. However, the frictional resistance is required so that the upstream compressor can build a corresponding compression pressure. In the area of the first heating plate (s), the circumference of the pressure channel is not completely covered, so that peripheral areas not melted on the plastic pressed part remain. These provide the necessary frictional force for generating the pressure build-up. The same applies analogously to the area of the second heating plate (s). Here, too, despite the surface fusion sufficiently high frictional forces between the channel wall and plastic compact formed. The fact that different peripheral sections are heated sequentially, mutually complementary molten and re-solidified skin sections arise with sufficiently high total area while maintaining the back pressure.

Advantageously, two first heating plates relative to the cross section of the pressure channel are arranged in pairs opposite one another and spaced apart in the circumferential direction. Opposite portions of the outer surface of the plastic compact are melted in the desired manner, while in the region of the circumferential distance such melting does not occur. Due to the distance formed in the circumferential direction between the first heating plates remain surface areas of the plastic compact, which are not melted at this point, and here generate the necessary frictional forces to build up a pressing pressure. In an advantageous development, two second heating plates are arranged opposite one another in pairs relative to the cross section of the pressure channel and at a distance from one another in the circumferential direction and are located in the distance regions between the first heating plates relative to the circumferential direction of the pressure channel. Accordingly, the continuous plastic compact is melted sequentially first on two opposite sides and then subsequently on the two remaining sides. Overall, therefore, four sides of the plastic compact are melted, creating a circumferentially at least approximately closed skin. For less critical materials such as EPP, a three-sided melt can be sufficient to keep the plastic molding in shape. For more difficult to handle materials such as EPE, the four-sided melting leads to an at least approximately closed around skin, which reliably prevents subsequent expansion of the cross-section. The spatial displacement of the first and second heating plates relative to the direction of passage causes only a partial melting of the surface takes place at both heating points, while the other, not melted or already re-solidified surfaces apply the frictional forces required for the pressing pressure.

In a preferred embodiment, a particular pivotally mounted pressure flap is provided for adjusting the free cross section in the pressure channel, wherein the melting device acts on the pressure flap. The position of the pressure flap is used to set the free cross section in the pressure channel. The tighter this free cross-section is, the more lower is the feed rate of the plastic compact, and the higher the pressure built up by the compressor and the degree of compaction achieved. With simple means, a clean process control for achieving a uniform degree of compaction can be performed. By the action of the melting device on the pressure flap, a surface fusion takes place such that the predetermined by the respective position of the pressure flap cross-sectional shape is fixed. Subsequent inflation of the plastic press is reliably avoided.

The pressure flap advantageously has on its side facing the inside of the pressure channel surface at least one friction strip and preferably a plurality of friction strips. The friction strip is in particular V-shaped. Over the comparatively short overall length of the pressure flap, sufficiently high frictional forces can be exerted on the plastic press by means of the friction strips despite the remelting device acting there, so that a uniformly high compression of the foamed plastic material in this area is achieved. The V-shape of the friction strip prevents portions of the passing plastic material from settling in a ramp on the input side of the friction strip, which would otherwise contribute to an undesirable reduction in the friction effect. Rather, the structurally specified friction effect is permanently retained.

It may be expedient to use a hydraulic or pneumatic cylinder as a compressor, for example, whereby individual batches of the plastic material are compacted discontinuously. Preferably, the compressor is continuous Loan working and in particular designed as a screw compressor. The result is a continuous compaction process which, in conjunction with the downstream smelting device, produces a uniform pressing and smelting result. The plastic compact produced here as a continuous material has a good, uniform quality, which improves the efficiency of further processing.

In an advantageous embodiment, the screw of the screw compressor protrudes freely cantilever into the associated compressor chamber and is located at a radial distance to the walls of the compressor chamber. The worm has at its end facing the pressure channel on a centering cone. It has been found that the radial distance of the screw to the walls of the compressor chamber is required in order to avoid local thermal damage to the plastic material. However, the concomitant cantilevered storage of the screw is not stable without further measures, which is why the screw can migrate during operation in the radial direction. However, the arrangement of the centering cone leads to the surprising effect that the centering cone in the output side of the screw forming plastic compact acts as a centering bearing, whereby the structurally predetermined radial distance to the walls of the compressor chamber is maintained during operation.

The aforementioned radial distance is advantageously in a range of 5 mm to 7 mm inclusive inclusive. At smaller radial distances thermal damage to the plastic material to be feared while at larger radial distances an insufficient pressure is built up. In the above range of values, however, the pressing pressure is in the desired frame, without combustion phenomena or the like being observed on the plastic material.

The compression system according to the invention is basically suitable for all expanded thermoplastics. The melting device is preferably matched in its heating power to EPP and / or EPE. These materials have been found to be particularly difficult to achieve a durable die to maintain. By adjusting the heat output of these materials, their melting point is slightly exceeded in the range of 120 ° C to 130 ° C at the surface, so that the desired, shape-retaining surface fusion sets without material damage. The resulting plastic compact reliably retains its compacted shape and can be easily assembled by scoring the melted and already solidified surface to the desired degree.

However, these and comparable materials show further disadvantageous properties during processing in the compaction system. Thus, especially after passing through a crusher upstream of the compressor, lumping is observed. This can lead to machine downtime. To eliminate this problem, a control room, in particular with a level control, is preferably arranged between the crusher and the compressor. For example, through a viewing window of the Kontrollräumes can be checked regularly that the In the crusher pre-shredded material falls clean into the compressor. If the level in the control room increases too much, the upstream breaker can be operated according to the visual observation or preferably by the aforementioned level control with lower power or temporarily even switched off. Blockage of the system is avoided. Rather, the compression system can be operated continuously with constant quality even when feeding critical plastic materials.

An embodiment of the invention is described below with reference to the drawing. Show it:

Fig. 1 in a schematic, partially sectioned

Side view of an inventive compression system with a crusher, a screw compressor and a downstream pressure channel, wherein the pressure channel is provided with a Anschmelzeinrichtung;

Fig. 2 is an enlarged detail view of the arrangement of Figure 1 in the connection region between the compressor and the pressure channel with details of the arrangement of heating plates to form the Anschmelzeinrichtung.

Fig. 3 is a cross-sectional view of the arrangement according to

Fig. 2 in the region of the cross section of the pressure channel adjusting pressure flap; Fig. 4 in a plan view of the pressure flap of FIG. 3 with arranged thereon V-shaped friction bars.

Fig. 1 shows in a partially sectioned side view of an inventively designed compression system for foamed, in particular thermoplastic plastic material. The compression system comprises a compressor 1, above which, opposite to the direction of gravity, a breaker 14 for the foamed plastic material is arranged. The compressor 1 is followed by a pressure channel 2, which extends in the horizontal direction. In detail, the compression system is structured as follows:

The crusher 14 comprises a housing in which toothed rollers 20 are rotatably mounted with a horizontal axis of rotation. The toothed rollers 20 are driven in opposite directions by means of an electric drive motor 19 at low speed. Foamed plastic material such as EPS, EPE or EPP, which is obtained, for example, as a packaging waste, is supplied to the crusher 14 in large pieces and substantially uncrushed by means of a hopper 21. The rotationally driven toothed rollers 20 break these pieces into small and medium size fragments of irregular shape and size. These crushed fragments fall automatically under the action of gravity down from the crusher 14 out in the compressor. 1

The compressor 1 may be, for example, a hydraulically or pneumatically driven piston / cylinder unit or the like and is designed in the illustrated embodiment as a continuously operating screw compressor. The screw compressor has a two-stage screw 10 with a first diameter range and a comparatively smaller second diameter range. The worm 10 is located with its horizontal axis of rotation in a compressor chamber 11 which is open on the input side and up to receive the falling out of the crusher 14 plastic material.

Opposite to the pressure channel 2, the screw 10 is mounted on one side by means of a bearing unit 23 on an end wall of the compressor chamber 11. Starting from the storage unit 23, the worm 10 projects freely into the compressor chamber 11 without further storage or support. On the opposite side of the worm 10 of the bearing unit 23, an electric drive motor 22 is flanged, by means of which the worm 10 is driven to rotate.

On its side opposite the drive motor 22 and the bearing unit 23 side of the compressor chamber 11 opens into the pressure channel 2. The direction of rotation of the drive motor 22 and the worm 10 is selected such that the falling into the compressor chamber 11 plastic material is conveyed into the pressure channel 2. In the pressure channel 2 arise between its walls and the plastic material pressed through there frictional forces, which counteract the promotion of the synthetic material. As a result, on the output side, the screw 10 in the compressor chamber 11 builds up a high pressure, which acts on the plastic material, and under the action of which the foam bubbles and other cavities in the plastic material are compressed. About a pressure flap 8 described in more detail below, which is adjustable by means of a spindle 29, the resistance to penetration of the plastic material through the Pressure channel 2 and consequently set the compression pressure in the compressor 11 such that the large-volume foamed plastic material is compressed compact. The volume of the foamed plastic material is reduced to a fraction of it while the density is increased many times and approaching that of the non-foamed plastic material. Accordingly, a highly compressed plastic compact 3 forms in the pressure channel 23, which emerges from the free end of the pressure channel 2 in a direction of passage 7 indicated by an arrow. In the continuous compressor 1 shown here, the plastic compact 3 is an endless strand, which can be cut or broken on the output side of the pressure channel 2, for example, into stackable and manually manageable blocks.

In order to ensure a certain cohesion of the plastic compact 3 after its exit from the pressure channel 2 in certain plastic materials, in particular in EPP and EPE, the pressure channel 2 is provided with a melting device 4 for melting at least a part of the surface of the plastic compact 3. The melting device 4 can be equipped with various heating devices. In the embodiment shown, the melting device comprises at least one heating plate 5, here several heating plates 5, 6. The heating power of the melting device 4 is adjusted to the melting point of the pressed through the pressure channel 2 plastic material - here EPP and / or EPE - such that its melting temperature of about 120 ° C to 130 ° C in the surface region of the plastic compact 3 is exceeded. The temperature is, however, limited to that the molten plastic material does not undergo overheating or thermal damage. After passing through the plastic compact 3 by the Anschmelzinrichtung 4 solidifies its melted surface due to cooling. It forms a coherent skin that at least partially surrounds the not melted, consisting of compressed plastic fragments core of the plastic compact. 3 Without the fragments lying in the core having to make a firm bond with each other, the strand shape of the plastic compact 3 is maintained by the supporting action of the skin formed from the plastic material. In addition, the skin formed by the AnschmeIzVorgang prevents the plastic compact 3 inflates after leaving the pressure channel 2 due to its elastic restoring forces back to its non-compressed initial volume. The plastic compact 3 formed in this way maintains its shape and can be cut to manageable blocks following the exit from the pressure channel 2 by scratching the skin with a knife. Due to the absence of an internal fusion of the plastic material, a block which can be handled as a single piece can then be broken off at the point scratched by the knife and fed to its further processing or storage.

Between the crusher 14 and the compressor 1, a control room 15 with a window 17 is arranged. The control room 15 acts as a buffer for crushed in the crusher 14 plastic material. For problematic materials such as EPP or EPE, the level in the control room 15 must not exceed a certain level in order to avoid bridging or clumping of the plastic material. A visual control of the level is possible through the window 17. Optionally, a level control 16 is provided, which includes a schematically indicated light barrier 18 in the illustrated embodiment. The light barrier 18 detects through the window 17 through the level in the control room 15. It is further connected to the crusher 14, the compressor 1 and / or the pressure flap 8 in such a loop that the level in the control room 15 does not exceed its intended limit ,

The illustration of FIG. 1 can still be seen that the compression system 1 is provided in the region of the compressor 1 and the crusher 14 with rollers 24, whereby the compression system is mobile. As part of a recycling plant, the compaction system can be used in different locations. The comparatively long, laterally projecting over the compressor 1 pressure channel 2 is supported at the site by means of supports 25 relative to the ground.

2 shows an enlarged detail of the arrangement according to FIG. 1 in the region of the transition from the compressor 1 to the pressure channel 2. According to the illustration according to FIG. 3, which will be discussed in more detail below, the pressure channel 2 comprises a cross-sectionally U-shaped channel. shaped, upwardly open lower part 34, which is closed at the top by means of a pressure flap 8. 2, a closed cross-section of the pressure channel 2 is formed in the region of the pressure flap 8, to which the U-shaped, upwardly open cross-section of the lower part 35 adjoins with respect to the passage direction 7. The pressure flap 8 is pivotally mounted on its input side by means of a hinge 26. But it can also be a linear adjustability of the pressure flap 8 appropriate. To adjust the position of the pressure flap 8 relative to the lower part 34, a spindle 29 is provided, which is driven by an electric drive motor 27 via an intermediate angle gear 28. As a result, the pressure flap 8 can be pushed or pivoted into the interior of the lower part 35 according to an arrow 30, whereby the free cross section in the pressure channel 2 can be adjusted.

Relative to the passage direction 7, behind the pressure flap 8, a speedometer 31 is arranged, which encloses a swivel arm 32 with a wheel 33 fastened thereto. The wheel 33 rolls on the surface of the guided in the pressure channel 2 plastic compact 3 (Fig. 1) and thereby determines the speed of movement of the plastic compact 3 (Fig. 1) in the direction of passage 7. By adjusting the pressure flap 8 in the direction of arrow 30 or In the opposite direction, the passage speed of the plastic compact 3 (FIG. 1) through the pressure channel 2 can be adjusted. At constant speed of the screw 10, thereby changing the pressure in the compressor chamber 11 upstream of the transition to the pressure channel 2, whereby the compression ratio of the compacted foamed plastic material can be adjusted. The pressure in the compressor chamber 11 is determined by frictional forces between the plastic compact 3 (FIG. 1) and the walls of the pressure channel 2. For this it is important that these friction forces are precisely reproducible. At least the walls of the pressure channel 2 are therefore made of stainless steel to To eliminate changes in frictional properties due to corroded surfaces.

The illustration according to FIG. 2 also shows that the screw 2 of the compressor 1 designed as a screw compressor lies at a radial distance a from the walls 12 of the compressor chamber 11. This radial distance a is advantageously in a range of from 5 mm to 7 mm inclusive. Furthermore, the screw has a centering cone 13 at its end facing the pressure channel 12. The term selected here of the centering cone 13 encloses next to the exact conical shape and similar, for example, rounded shapes. In operation, this centering cone 13 is located in the region of the already compressed synthetic material and acts as a radial bearing for the freely projecting end of the screw 10. This ensures that the radial distance a from the walls 12 is maintained during operation. The radial distance a is small enough to produce a sufficiently high pressure in the compressor chamber 11, and large enough so that set in the region of the distance a no melting or even thermal damage to the plastic material.

Fig. 3 shows a cross-sectional view of the pressure channel 2 in the pressure flap 8. A bottom 35 and two laterally opposite side walls 36 of the lower part 34 together with the pressure flap 8 is an approximately rectangular free cross section of the pressure channel 2, whose corners are chamfered. But it can also be useful, for example, rounded cross-sectional shapes. Distributed over the circumference of the pressure channel 2 are a total of four Heating plates 5, 6 are arranged, which together form the melting device 4 (Fig. 1). Two first heating plates 5 are arranged in pairs opposite one another and in the circumferential direction at a distance from one another in relation to the cross-sectional pressure channel 2. For this purpose, one of the first heating plates 5 lies on the bottom 35 of the lower part 34, while the other first heating plate 5 is arranged opposite to the pressure plate 8. In a rotation angle offset by 90 ° to a pair of second heating plates 6 is provided, wherein the two heating plates 6 are also opposite in pairs on the two side walls 36 and are also arranged in the circumferential direction of the pressure channel 2 at a distance from each other. The second heating plates 6 are based on the circumferential direction of the pressure channel 2 in the distance regions between the first heating plates 5. Conversely, the first heating plates 5 are relative to the circumferential direction of the pressure channel 2 in the distance regions between the second heating plates 6. In conjunction with FIG In addition, that the pair of second heating plates 6 relative to the passage direction 7 by far behind the pair of the first heating plates 5. This ensures that initially only the top and bottom of the Kunststoffpress- lings 3 is melted, while in the region of the side walls 36 no such melting is made. On the side walls 36, the frictional force required for the build-up of the counter-pressure is set here. The axial distance between the heating plates 5 and the heating plates 6 is sufficient at the usual flow rate of about 0.4 mm per second in the direction of passage 7 that cool the areas melted on the heating plates 5 and solidify before the remaining side surfaces of the plastic Pressing 3 (Fig. 1) on the side walls 36 also be melted. At this point, then form the necessary friction forces on the bottom 35.

Depending on the application, it may be sufficient that only a first heating plate 5 is used in conjunction with two second heating plates 6. Conversely, it may be appropriate that only a second heating plate 6 is used in conjunction with two first heating plates 5. In any case, the number and distribution of the heating plates 5, 6 to be chosen so that they act on at least 50% and preferably at least 70% of the circumference of the plastic compact 3, whereby in the circumferential direction at least approximately a closed plastic skin is formed by the AnlegeIzVorgang. The individual fused and solidified to a skin surfaces do not have to be flush with each other, but may also be spaced from each other according to practical experience. However, it may also be expedient to arrange the heating plates 5, 6 relative to one another in relation to one another in relation to the circumferential direction of the pressure channel 2 such that, for example, the bevelled cross-section corners are also included and that a plastic skin closed in the circumferential direction is produced.

The illustration of FIG. 3 can be further seen that the pressure flap 8 has on its the inside of the pressure channel 2 facing surface at least one friction strip 9. For details, see the plan view of the pressure flap 8 of FIG. 4. Accordingly, several, in the embodiment shown, a total of four friction strips 9 are arranged at a distance from each other here. They cause in the area of the pressure flap 8 an increase in the frictional resistance on the plastic compact 3 (FIG. 3). This is required because the pressure flap 8 compared to the lower part 34 with respect to the passage direction 7 (Fig. 2) is significantly shorter. The friction strips 9 can be rectilinear transverse to the direction of passage

7 are arranged. Preferably, they are V-shaped, wherein the tip of the V-shape in the opposite direction to the passage direction 7 has. This avoids that the vorbeigleitende plastic material deposits upstream of the friction strips 9 and forms a reibwertmindernde ramp. From the comparison with Fig. 2 it follows that the upper heating plate 5 relative to the passage direction 7 behind the area with the friction strips 9 on the pressure flap

8 is arranged. The friction strips 9 thus act on the not yet melted surface of Kunststoffpress- lings 3 and can thus develop their full effect.

Claims

claims

A compression system for foamed thermoplastic material comprising a compressor (1) and a compressor (1) connected downstream

Pressure channel (2) for forming a Kunststoffpress- lings (3), characterized in that the pressure channel (2) with a Anschmelzeinrichtung (4) for melting at least a portion of the surface of the plastic compact (3) is provided.

2. Compaction system according to claim 1, characterized in that the melting device (4) acts on at least 50% and preferably at least 70% of the circumference of the plastic compact (3).

3. Compaction system according to claim 1 or 2, characterized in that the melting device (4) comprises at least one heating plate (5, 6).

4. Compaction system according to claim 3, characterized in that at least one first heating plate (5) and at least one second heating plate (6) are provided, wherein the at least one second heating plate (6) at a distance behind the at least one first heating plate (5) is, wherein the circumference of the pressure channel (2) in the region of the respective first and second heating plate (5, 6) is not completely through the at least one first Heating plate (5) or by the at least one second heating plate (6) is covered, and wherein the at least one first heating plate (5) and the at least one second heating plate (6) in different peripheral portions of the pressure channel (2).

5. Compaction system according to claim 4, characterized in that two first heating plates

(5) in relation to the cross section of the pressure channel (2) are arranged in pairs opposite one another and in the circumferential direction at a distance from each other.

6. Compaction system according to claim 5, characterized in that two second heating plates

(6) relative to the cross section of the pressure channel (2) in pairs opposite and circumferentially spaced from each other, and relative to the circumferential direction of the pressure channel (2) in the spacing regions between the first heating plates

(5) lie.

7. Compaction system according to one of claims 1 to 6, characterized in that a particular pivotally mounted pressure flap (8) for adjusting the free cross section in the pressure channel (2) is provided, wherein the melting device (4) acts on the pressure flap (8).

8. Compaction system according to claim 7, characterized in that the pressure flap (8) facing on its inside of the pressure channel (2) Surface at least one friction strip (9) and preferably a plurality of friction strips (9).

9. Compaction system according to claim 8, characterized in that the friction strip (9) is V-shaped.

10. Compaction system according to one of claims 1 to 9, characterized in that the compressor (1) is designed to work continuously and in particular as a screw compressor.

11. A compression system according to claim 10, characterized in that a screw (10) of the screw compressor cantilever into a compressor chamber (11) protrudes and at a radial distance (a) to walls (12) of the compressor chamber (11), and that the Screw (10) at its the pressure channel (12) facing the end of a centering cone (13).

12. Compaction system according to claim 11, characterized in that the radial distance (a) is in a range of from 5 mm to 7 mm inclusive.

13. Compaction system according to one of claims 1 to 12, characterized in that the melting device (4) is tuned in its heating power to expanded polypropylene and / or expanded polyethylene.

14. Compaction system according to one of claims 1 to 13, characterized in that the compressor (1) is preceded by a crusher (14) for comminuting the foamed KunstStoffmaterials, and that between the crusher (14) and the compressor (1) a control room ( 15) is arranged in particular with a level control (16).