EP1068069A1

EP1068069A1 - Method and device for producing continuous extrusion profiles and extrusion tubular profiles from small parts

Info

Publication number: EP1068069A1
Application number: EP99916880A
Authority: EP
Inventors: Karl Schedlbauer
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-03-25
Filing date: 1999-03-23
Publication date: 2001-01-17
Also published as: WO1999048675A1; EP1066138A1; DE19980474D2; EP1068068A1; DE59914093D1; DE19980473D2; EP1066138B1; AU3811799A; DE19980475D2; AU3147299A; WO1999048659A1; WO1999048676A1; AU3521299A; ATE349305T1

Abstract

The invention relates to extrusion profiles and extrusion tubular profiles made of small parts with or without bonding agents which do not or which slightly flow under compression. During production, compression is generated by pressing spirals. According to the invention, a spiral is used whose transport path enlarges up to the end thereof which is located on the extruded section side. Control of the compression can additionally be improved in an advantageous manner by changing the insertion depth of the spindle or of a mandrel into the extruded section. The mixture from idling is prevented from rotaring the spirals are prevented from turning by the cross-section of the mandrel and by the gaps which expand in the direction of pressing and which are situated between the pressing spirals. The insertion depth of the spirals, worms or mandrel is preferably computer controlled in order to limit compression.

Description

Method and device for the continuous extrusion and extrusion of small parts

The invention relates to a method and an apparatus for extruding and extruding tubes of small parts.

Corresponding small parts can be comparatively strongly compressed and can be pressed close together, but in this state they are only partially flowable and can only be pressed to a limited extent by nozzles contoured according to a desired profile cross section. The possible small parts are, for example, small plant parts such as wood chips or Tetra-Pak small parts. The problem with the processing of these small parts is that sufficiently stable profiles can only be produced with carefully prepared batches that are largely constant in their composition and sieve line with a comparatively large amount of binder added. The production speeds are comparatively low with complex professional cross-sections.

Under the impression of this problem, the invention has for its object to provide a method and an apparatus for the production of extruded profiles, so that mechanically high-quality and improved in surface quality extruded profiles can be produced with a comparatively high extrusion speed.

This object is achieved by a method with the features specified in claim 1.

With regard to a device for producing an extruded profile, this object is achieved by a device with the features specified in claim 12.

Advantageous embodiments of the invention are the subject of the dependent claims. Using the method according to the invention and with the device according to the invention, small mineral parts such as pulverized waste or recycled expanded concrete or expanded glass can also be processed to extruded profiles in an advantageous manner

In accordance with the solution according to the invention, it is advantageously possible to dispense with intermittently operating reciprocating piston systems in which the strand is formed in individual strokes, with one strand section being pressed onto the previous one with each press stroke. The mechanically less resilient connection points produced between the press strokes formed in this way are pressed

Strand sections no longer occur in the method according to the invention. The solution according to the invention also results in a profile which is considerably more homogeneous and more uniform over the entire length of the profile with respect to its density and also with a particularly favorable alignment of the individual small parts in the structure of the strand formed

In a further advantageous manner, the profiles according to the invention can be produced in a reliably controllable manner partly without or at least with a significantly reduced addition of binder and with extremely low energy consumption. Differences in density in the strand can be reliably avoided

In an advantageous manner, the small parts can not only be required, but also sufficiently compressed with the compression spring front spirals according to the invention, if the compression channel has at least approximately the same dimension over the entire length. Sufficiently compressed strands can be produced which consistently have the desired density and in compression can be controlled

In a particularly advantageous manner, the press spiral is either formed from wire tapering in the pressing direction or from a sheet metal strip which is widest on the other side and tapers towards the strand. This sheet metal strip becomes a spring with the same inside and outside diameters over the length and constant pitch The taper creates a press spiral, whose spaces between the spirals also change in the preferably continuously increase the tensioned state towards the strand. In the working state, the spiral generates the pressing pressure and, in turn, is compressed if necessary. Since the batch is supported, advantageously, on the walls of the baling chamber, the shortening takes place unevenly, towards the strand to an ever greater extent. With appropriate material strength of the press spiral, such a press spiral strands of medium density, such as. B. produce those from small wooden parts with about 650 g / dm ³ . For a higher compression, it is advantageously proposed to design the starting sheet in a large arc.

The width of the spring is preferably 1.5 to 5 times the thickness. When winding, a spring with an uneven pitch now arises, which can be installed in the device such that the largest gap is on the strand and the smallest on the side of the drive. This spiral formation enables comparatively high specific compression pressures to be achieved, for example 800 N / cm ² for small wooden parts. This results in a density with a dryness of the mixture of 9% dry (absolutely dry) of about 750 g / dm ³ . An even higher compression can be achieved by a combination of both types of spiral shape. They are particularly suitable for small parts, for example made of composite material (Tetra-Pak) or expanded concrete, which require such compaction. For this purpose, it is advantageously proposed to make the sheet metal wider in the area of the attachment to the drive and to taper it to the width of the press spiral in a conical transition, which can be about half a revolution long.

In the working state, that is under pressure, the described spiral designs result in a spring, the gaps of which do not shrink toward the strand, but at least slightly enlarge in a particularly advantageous manner. For a pallet block with a diameter of 82 mm, a press spiral has proven its worth, which was wound from an approximately 15 mm thick steel sheet or a steel tube with a wall thickness of approximately 15 mm, in particular machined. The width of the sheet is preferably determined on the underside with approximately 30 mm and on the strand side with approximately 5 mm. The durability of the spring can be increased in that the drive-side half of the spiral is made largely in parallel width and the tapering takes place only in the strand-side half. The Bending load of such a press spiral is greatest in the area of the drive end. This end is therefore expediently made wider or more stable.

A significantly improved speed / output ratio can be achieved with the press spirals described. Since the invention generally does not use small parts or only flows to a limited extent, it is possible to produce not only round but also, in a particularly advantageous manner, angular or polygonal strands.

For example, with a press spiral with an inner diameter of approximately 45 mm, an outer diameter of approximately 90 mm and a pitch of approximately 80 mm with an initial width of the press spring plate of approximately 40 mm, pallet block profiles of 100 x 145 mm can be extruded in strands. In this example, strands with and without holes were created. These strands usually have a hole of 32 mm in diameter. However, square holes of 30 x 30 mm and hexagonal holes with a wrench size of 32 mm can also be advantageously introduced by means of corresponding mandrels. When using these mandrels, the extruder output can be increased considerably compared to mandrels to form round holes at the same speed of the press spiral. The reason for this improved output is that the small parts of the batch in the inner region of the strand with a round mandrel can rotate in part spirally during compression. This is largely prevented by the polygonal mandrels.

The mandrels are used in a particularly advantageous manner to control the compression. This is achieved in an advantageous manner by controlling the length in which the mandrel protrudes into the strand, since the density of the strand is due to its friction on the walls of the filling and pressing chamber, of the reactor which follows and of the subsequent heating duct and of the dome results. The longer the mandrel protrudes through the spiral into the strand, the greater the friction and the higher the density of the strand produced.

According to a particularly preferred embodiment of the invention, the mandrel is connected to a tension or pressure load cell. The tensile force of the strand is in an equivalent ratio to the degree of compression If a too high tensile force, ie too high a compression is measured via the pressure transducer, a linear motor -Z B a hydraulic cylinder pulls the mandrel a piece out of the strand. In the opposite case, the linear motor lets the mandrel further into the strand protrude until the desired tensile force and compaction is reached If necessary, the mandrel can also be positioned in the strand so that it can be adjusted by hand or by means of a thread without a pressure sensor Press can be measured, a less precise density control is achieved as with the aforementioned automatic mandrel adjustment or friction force control

In thornless extrusion, it is advantageously possible to carry out a density control via the heating duct. This essentially consists of a rigid and a movable part. The movable part is preferably pressed by means of adjustable clamping elements, e.g. hydraulic cylinders, against the rigid part. By changing the clamping force determine the density of the strand. This system can also be used in an advantageous manner when pressing with mandrels. The mandrel is preferably not changed in the depth of immersion in the rod, but rather only attached to a pressure transducer. This determines the tensile force on the mandrel and a control system is calculated and determines the necessary contact pressure of the clamping elements

It has proven to be particularly expedient to carry out the presses horizontally, in particular in the case of devices with a high output of, for example, 8 meters / minute and more Pallets block the size 145 x 145 mm about 70 meters long For thin panel profiles or chipboard panels for doors, it is also possible to choose a vertical design.This is particularly true when using several spirals next to each other or when manufacturing products that are particularly high, e.g. more than 800 g / dm ³ must be compressed. In the case of vertical presses, the clamping parts enter the area of the press spirals preferably all the way round 6

i.e. around the entire circumference of the spiral, but essentially predominantly from the top in the case of horizontal presses. The press spiral of vertical presses can therefore be made shorter and heavier than the press spiral of vertical extrusion presses with a longer inlet zone. In addition, in the case of vertical training, the entry of the batch is hampered to a lesser extent by the relatively wide passages of the press spirals on which the batch may be supported.

As previously described, it has been found that square or non-round profiles, the side lengths of which have a ratio of up to approximately 2: 1, can also be advantageously compacted or manufactured with a single conveyor spiral. For the production of panels or complicated profiles, the invention provides for the use of several press spirals side by side. These can be parallel to each other at a distance of a few mm to about 4 cm and rotate either in the same or in opposite directions.

For the production of chipboard panels for doors, it is proposed to arrange the conveying spirals preferably intermeshing, that is to say overlapping. This makes it possible, for example, to insert hexagon holes with a key width of 24 mm into a chipboard plate with a thickness of 33 mm, the hole spacing of which only needs to be about 5 mm larger than the corner dimension of the hexagon.

The mandrels are heated in a particularly advantageous manner. This can be done with electrical resistance heating, steam or heat transfer oil. Other types of heating with corresponding heating output are also possible.

In a particularly advantageous manner, it is possible to produce a higher-density and therefore particularly smooth edge zone in the strand by supplying steam. For this purpose, the gem. EP 0 376 175 proposed measures can be used. These measures can also be used to control the compression and reduce the friction.

The use of epoxy binders has proven itself in a number of small parts. This applies, among other things, to expanded glass. More about the composition of a /

Binder containing epoxy resin is described in EP 0 290 881. The use of the reactor according to EP 0 376 175, which is particularly advantageous in the present case, is expediently carried out for all binders with high adhesive strength on metals, that is to say also for. B for isocyanate adhesives or paint residues from powder or electrostatic painting. These binders are adjusted in such a way that they react and set very quickly when exposed to heat. They may stick with great adhesion to the inside of the reactor or the subsequent heating duct. In a particularly advantageous manner, water or steam or liquid or vaporous separating agent is introduced between the inner wall of the reactor and the strand by means of a reactor according to EP 0 376 175. The steam or the release agent on the one hand does not hinder the entry of heat into the strand, but even promotes it on the other hand there is no sticking of the rod to the reactor wall.

In a further particularly advantageous manner and based on the teaching of EP 0 376 175, the invention teaches not only to introduce the water, the steam or the separating agent over the length of the reactor, but also to provide the inner walls of the heating duct with outlet openings for the said agents , since various binders not only adhere to the heating duct wall until they have hardened, but as long as they are exposed to heat. This is particularly true for paint waste powder from electrostatic painting systems.

Contrary to the previous opinion, it is advantageously possible to dispense with the previously required drying of the small wooden parts down to 0.5 to 2% dry without the risk that steam cracks would occur. After a fixed preheating cycle or a reactor, however, the strand is cured in heating channels which are not closed on the back. However, the water vapor generated during curing hardly builds up pressure, since the steam can escape through the gaps between the heating plates. In contrast, the invention teaches to keep the moisture when pressing small plant parts, in particular small wooden parts, as large as possible as the binder used allows. The drying of wood chips to 0.5 to 2% dry for pallet blocks, furniture profiles or chipboard costs up to 30% of the manufacturing costs of the product. Most of these costs can be saved since the possible moisture in the invention can be more than 25% dry.

No drying is required for various applications and small wooden parts. The invention, however, sees the use of small plant parts with the high humidity mentioned as a further very decisive advantage: the wetter the small parts are, the lower the force required for compaction. Not only does it reduce the drive power, but it is also possible to manufacture higher-density strands with relatively light press coils. Since, on the one hand, the usual chipboard binders do not or hardly stick to the walls of the reactor, preheating and heating duct, and on the other hand, the strand dries out when hardening from the outside and thus has an increasingly heat-insulating effect, the invention here teaches that the further steam input after the reactor is not continuous over the whole Strand, but in one or more short sections. For example, with a heating channel length of 70 meters in, for example, about 10 steam zones of about 100 to 1000 mm in length, which are at a distance of about 10 m from one another. The steam subsequently introduced acts as a heating medium for the transfer of heat.

In the extrusion of small mineral parts according to the invention, such as waste or recycled powder or granules of expanded concrete, the reactor takes on further functions. The flow behavior of the powder formed by more or less spherical particles is on the one hand greater than that of more flat small parts such as wood shavings, on the other hand a much higher specific pressing pressure of about 200 to 600 kp / cm ^{2 is} required. In addition to the high friction, part of the pressing force is projected outwards against the press chamber wall by the spherical shape of the small parts. Even with a friction-reducing coating, the pressing space can only be carried out very briefly from the pressing pressure. This can lead to so-called twofold growth, ie the small parts inside flow faster during compression than those in the peripheral zone. It may not be possible for a strand to form here, rather the mixture virtually crumbles out of the baling chamber. The invention remedies this in a simple manner. It positions the press vertically, so that the press spiral can be formed with the necessary brevity and strength. It also lets the first outlet channel for water, steam or release agent begin about 1 to 3 cm after the lower end of the press spiral. This measure is determined in such a way that the compacted mixture seals the filling space towards the reactor. No binder is required for expanded concrete. Rather, it has been found in tests that the strand is hardened by further autoclaving under steam pressure and that the small parts are connected much better to one another. The invention therefore does not require a curing channel in this case. It forms the filling and pressing chamber preferably in a run, which is provided with wear parts. By introducing water or a lubricant between the strand and the inner wall of the tool, the coefficient of friction between the strand and the baling chamber / reactor can be reduced in such a way that the baling chamber can be formed to the necessary length, which reliably prevents the formation of twofold growth. Without the reduction in friction by the reactor, this would not be possible. Wall extrusion with holes reduces the wall thickness in the strand. This also reduces the tendency towards twofold growth.

The dual growth can be countered in a further advantageous manner by using two or more press spirals, which work at different speeds or conveying speeds. The internal press spiral is longer than the outer one, which means that it acts as a brake against the dual growth. This application is particularly suitable for more or less partially flowing materials, such as expanded glass, which can be brought to a comparatively low compression of 120 to 200 N / cm ² .

In the case of horizontal extrusion presses, the press spiral is filled through an inlet shaft. It has been found that the inlet improves when the shaft is divided into at least two or more chambers in the longitudinal direction, with each chamber widening conically towards the press spiral. In contrast to a single long chamber, the tendency to form bridges is reduced considerably. In the case of vertical extrusion presses, the rear part of the press spiral, a piece of approximately 1 to 3 spiral courses, protrudes from the press chamber. The batch can be filled using simple, rotating funnels, which in turn are equipped with conveyor spirals or similar. be fed. Other types of feeding the batch into the conveying area of the press spiral are also possible.

The low energy requirement for compression has proven to be particularly favorable. A piston extruder, for example, requires approximately 35 kWh to compact 1 ton of wood chips, but the device according to the invention requires less than 7 kWh.

In the embodiment described above, the pressing force is generated by spirals, the spiral spacings of which remain the same or widen in the pressing direction. It has been shown that with the springs described above, strands of small wooden parts with a density of up to more than 1 kg / dm ³ can be produced until the spiral spins without conveying. This value is usually sufficient for the production of strands from small wooden parts. Advantageously, the strands are given a higher density outer layer, the thickness of which corresponds approximately to the distance between the spiral and the inner wall of the baling chamber. Particular attention must be paid to the fact that the small parts are squeezed between the spiral back and the inside of the press room. This may hinder the batch transport in the pressing direction, may heat the coil and reduce the possibility of controlling the compression by the mandrel and / or the heating channel. The whole system may get out of balance.

It was also found to be remarkable that an out-of-round mandrel, a hexagonal one was used in the experiment, reliably prevented the strand from rotating, but it was acted on by a very strong frictional force, as a result of which the batch flow in the pressing direction was considerably slowed down and the mandrel could be heated up very strongly .

If the pressure and the density are to be controlled even better, in particular to avoid that the press gets stuck, according to one particular advantageous development of the invention, a method and a device are proposed with which an extruded profile can be produced from small parts with or possibly also without a binder and in which the compaction of the batch can be controlled in a favorable manner.

This is achieved according to the invention by a method with the features specified in claim 34 and by a corresponding device with the features specified in claim 40. Further developments of these solutions are the subject of the subclaims which refer back to each.

Experiments with the device described above have shown that the strand, after leaving the spiral, has almost no endeavor to move outwards. According to a particularly preferred embodiment of the invention, a wedge-shaped extension of this heating duct part is provided, so that the cross section of the heating duct widens at least slightly in the conveying direction. This extension can be wedge-shaped or step-shaped. Experiments have shown that, depending on the type of small parts used, a press spiral length from the end of the inlet shaft of 0.3 to 4 turns is sufficient to achieve the required compression. Advantageously, there are no compression differences in the proposed spiral presses.

In the protruding spiral run, the mixture located between and within the spiral of the spiral is pushed forward. Furthermore, since the spiral rotates at a higher speed than the batch, the latter is transported into the heating duct in accordance with the slope and the small parts between the spiral and the inner walls of the pressing chamber are compressed much higher than the small parts in the region of the spiral. They are oriented in an advantageous manner longitudinally to the pressing direction and form a rigid outer layer, while the small parts within the spiral cross-section come to rest in the structure that is formed transversely to the pressing direction.

The highly compressed outer layer, which is advantageous in itself, generates a comparatively strong friction of the strand forming against the press room walls. The structure the friction and compression of the outer layer and, as a result, the inner zone may be self-reinforcing. The spiral may compress more and more. In order to remedy this problem it is advantageously possible:

- The spiral, if no special requirements are placed on the bending strength of the strand, to be so large in diameter that no or hardly any small parts are squeezed between the spiral back and the pressing space. The gap dimension can be between about 0.2 mm and about 2 mm.

- The spiral considerably none to manufacture than the press room, whereby the small parts in the gap are compressed only to a lesser extent than the small parts inside. The gap dimension can be more than 5 mm.

- The spiral back should not be cylindrical, but wedge-shaped in such a way that the larger diameter is towards the heating duct. Depending on the type of small parts, the wedge angle can be 5 to approximately 25 ° and / or

- To provide the spiral back with a step of about 0.5 to about 5 mm, so that the large diameter is also in the direction of the heating duct and the smaller diameter on the drive side. It has proven to be particularly advantageous in the case of small-area small parts to make the back of the spiral, which is larger in diameter, not in the pressing direction in a parallel width, but rather in the pressing direction to be reduced. That is, the rear wall of the spiral back has a larger slope than the front surface of the spiral.

- The spiral in the pressing direction, starting approximately at the level of the inlet end, tapering in the outer diameter and / or widening in the inner diameter. The tapering / widening, again depending on the type of small parts and the cross section of the strand, can be approximately 0.5 to more than 10 mm.

- The max. To limit the immersion depth of the spiral, depending on the type of small parts, about 4 turns, to store the spiral adjustable by means of spacers or displacement sensors in the immersion depth and to make the respective setting in such a way that the desired compression is reliably achieved with it, that only one up to about 5 to 15% higher compression can be achieved.

- To widen the pressing space adjoining the filling space with preferably parallel walls, from the end of the filling space up to approximately the height of the spiral end. In the case of small-area small parts, it is advantageous to enlarge the pressing space in one step or several steps from 0.3 to more than 5 mm directly at the inlet end and then to widen it in a wedge shape. 1 year

The slope of the spiral can be up to a little more than 20 °. With a spiral of 80 mm diameter, pitches of more than 90 mm can be achieved. In general, depending on the type of small parts, a pitch of 8 ° to 15 ° is selected. It is preferably proposed to bend the spiral from a sheet metal strip. However, only spring steel sheets up to about 15 mm thick are commercially available. Such a wall thickness is sufficient in terms of flexural strength, but the specific pressure on the mixture in the area of the helix may be too great. Therefore, according to a particularly preferred embodiment of the invention, it is proposed not to form the spiral from a drive shaft with an attached, bent helix, but to manufacture it by machining. This can be done relatively easily by turning or milling on CNC machines. In order to keep the surface pressure on the batch as low as possible, the invention proposes an inner diameter of the spiral which is only 1 to about 15 mm larger than the corner dimension of the polygonal or the diameter of the round dome.

The compaction of the batch takes place essentially in the spiral run within the press chamber. It is essentially in this run that it is necessary or at least advantageous to choose an ever increasing pitch of the helix. If a steadily increasing slope is selected and the helix is increased over the helix width, either the helix distance in the area of the inlet may be too small, which worsens the filling, or the helix width becomes too small, which may cause the spiral to bend in the press run and / or the spiral enlargement cannot be carried out to the required extent.

An approximately equal helix width is advantageously realized, the slope increasing. The spiral can be further optimized in that the slope is chosen to be approximately the same size up to the end of the inlet and is only increased correspondingly more in the press run. In contrast to curved spirals, the spiral can be machined with a much smoother surface. It is also possible for the end wall of the spiral in the pressing direction to be perpendicular to the pressing direction or in one, depending on the radial direction in which the small parts should move during compression to form obtuse or acute angles. Depending on the diameter, the increase in the pitch per revolution can amount to approximately 1 to more than 10% of the spiral diameter.

Since the spiral rotates at a significantly higher speed than the strand, corresponding to the spiral pitch, is transported forward, a considerable part of the drive energy is converted into heat by friction or friction. On the one hand, this heat is an advantage because it can get into the batch directly and without loss of time in the case of strands that are produced from small parts with a thermosetting binder. On the other hand, the coil can heat up so that it burns out. The invention provides for the use of hot working steels which are designed to reduce the coefficient of friction with a particularly smooth surface and further teaches to nitride the spirals, hard chrome plating or with another hard, low-friction coating, e.g. Titanium oxide. Nevertheless, it is advantageous to only allow the spiral to be immersed so deeply in the baling chamber that compaction is reliably achieved, since immersing it too deeply increases the heat development. The exact size can be predetermined by tests and may change. over time due to wear of the spiral, mandrel and press room.

According to a particularly preferred embodiment of the invention, it is proposed to arrange the spiral so as to be adjustable in length. This also makes assembly and disassembly easier. All components of the press are preferably mounted so that they can move longitudinally on slides or guides and are coupled with quick-release elements. The exact immersion depth of the spiral can be adapted or changed to the respective application using spacers, screws or displacement sensors. It has proven to be sufficient if the compression possible with the respective immersion depth can exceed the desired compression by a maximum of up to about 5 to 15%.

When manufacturing strands with piston extrusion presses, the small parts tend to move radially to a lesser extent. When extruding with spirals, this is prevented by the non-round or polygonal mandrels. However, the small parts are pressed against the mandrel with great force and produce a 13

counteracting high friction, which can heat the mandrel under certain circumstances and make it difficult to transport the batch. This large contact pressure arises essentially in the area of the press space in which the spiral is immersed. The friction can advantageously be significantly reduced by tapering the dome in this area. A measure of the taper of 0.2 to about 5 mm, depending on the mandrel profile and size, has proven to be sufficient. The invention makes use of the possibility of heat transfer via the mandrel or also the wall sections, if necessary both for cooling and for curing the strand in the case of small parts with heat-reacting binders.

According to DE A 198 26 408.9, a method and a device have been presented which heat the strand from the pinhole with steam, hot air, gas or a mixture thereof. The system advantageously works in a quasi-closed circuit. If water vapor or a water vapor / air mixture is used as the heat transfer medium, the invention teaches to guide the heat transfer medium through the ring surface between the mandrel tube and the inner tube, to lead it back along the strand towards the heating channel end to the openings in the inner tube and through this. Since the mandrel tube can have a much higher temperature than the heat transfer medium due to the friction, the latter is cooled and the heat transfer medium is heated at the same time. The mandrel works as a superheater. The heat transfer medium prevents the mandrel tube from burning out. If necessary, water can be added to the heat transfer medium, which evaporates in the annular gap between the mandrel tube and the inner tube and draws a correspondingly larger amount of heat from the condensing strand and also from the spiral.

The invention is concerned not only with extrusion molding, that is, the production of extrusions with holes, but also with extrusion, that is, the production of full extrusions. Particularly in the case of strands with a small cross-section or very thin profiles, such as door frames, extrusion tube pressing with holes may be less advantageous since the strength of the spirals may be too low. In this case, the anti-rotation lock is dispensed with due to the non-round or polygonal mandrel. The invention preferably uses a screw with an incline that also increases in the pressing direction. The The slope is increased as previously described for the spiral. In order to minimize the friction on the screw base, the invention teaches that the screw base diameter tapers in the pressing direction. The screw core is preferably not made conical.

Rather, the invention provides for the screw core to be approximately cylindrical up to approximately the inlet end and then to have a conical tip ending up to the front end. The spiral backs of the screw are designed as described for the spiral, i.e. with a shoulder and / or a slope. A snail has the advantage of higher strength compared to the spiral. It offers the possibility of making the incline less and choosing a thinner screw back. The invention therefore provides, in particular for larger screws, to carry them out in multiple passes, since these adjust themselves in the pressing chamber.

It is also possible to produce comparatively low-density strands by screws with a conical screw base. The range of application of the screws is usually limited by the amount of compaction. Instead of quasi-wound spirals, it is also possible in a particularly advantageous manner to use spirals turned for extrusion.

A turned spiral corresponds to a flat steel turned around its longitudinal axis to form a helix. Depending on the slope and the outer contour, this applies to coiled spirals. Twisted spirals are particularly suitable for the smallest and thin extrusion cross sections as well as for vertical extrusion presses. However, in order to achieve a particularly smooth surface, the invention does not provide for turning the spiral from a flat steel, but for machining it and treating it on the surface like the aforementioned screws.

The described designs of screws, spirals and baling chamber geometry can advantageously be combined with one another and in general, except for particularly complex profiles, allow operation in which the compression does not increase by itself and gets out of control. However, as the press gets stuck, it always comes to a standstill in which the one in the heating aisle Strand becomes unusable, and therefore the device must be restarted and strands with very unfavorable cross-sections react sensitively in the compression, the invention provides for the immersion depth of the dome to be determined by a computer and, if necessary, to be changed continuously. In order to shorten the adjustment path of the dome and to reduce the friction, she teaches the mandrel to taper, as already mentioned, in the area of the baling chamber, for example. The invention advantageously measures the tensile force on the mandrel, for example by means of a pressure cell, and the speed at which the strand exits the device. Next the driving force of the compression element. If the exit speed of the strand decreases and the tensile force on the mandrel increases and / or the force of the compression element changes, the immersion depth of the dome is adjusted by a displacement sensor, for example a hydraulic cylinder. If the exit speed decreases and / or the tensile force on the mandrel increases, the mandrel is pulled out a little from the strand. In the opposite case, the immersion depth is increased. The measurement data are processed in a computer. This ensures the production of strands with an exact and uniform density and prevents the press from getting stuck.

The spindle or spiral is preferably arranged in the device in such a way that it is inserted into the filling chamber in such a way that the spindle end facing away from the strand is sealed. For this purpose, a wall is preferably provided which has a spindle feed-through opening which is essentially adapted to the spindle cross section. Possibly. are provided in the corresponding through hole sealing means, for example, scraper rings through which an escape of the filled batch to the rear is avoided. The spindle or the spiral preferably has a pin section in the foot region, which is no longer penetrated by a threaded groove, so that a reliable sealing effect results from this smooth, cylindrical or conical section. Advantageously, any escaping gases or particles can be extracted via a suction device, which results in particularly low-emission operation of the system. The invention is described below by way of example without limitation of the general idea of the invention using exemplary embodiments with reference to the drawing, reference being expressly made to the rest of the details according to the invention, which are not explained in more detail in the text, in relation to the disclosure. Show it:

Figure 1 shows the cutting of a press spiral.

Figure 2 shows a section through a press spiral like Figure 1;

3 shows the cutting of a press spiral;

Figure 4 shows a section through a press spiral like Figure 3;

Figure 5 shows the cutting of a press spiral.

6 shows a longitudinal section through a horizontal extrusion press;

Fig. 7 is a section on the line I-1 like Fig. 6;

8 shows a section through a vertical extrusion tube press;

9 shows a section through a vertical extrusion tube press at the level of the filling and pressing space;

10 shows a cross section through a vertical extrusion tube press at the level of the filling and pressing space;

11 shows a cross section through a vertical extrusion tube press at the level of the filling and pressing space;

Figure 12 is a cross section through an extrusion tube press at the level of the baling room.

13 shows a section through an extrusion tube press;

14 shows a spiral with a continuously increasing slope;

15 shows a spiral with changing slope;

16 shows a partial section through a spiral;

17 shows a detail section through a helix;

18 shows a detail section through a helix;

19 shows a detail section through a helix;

20 shows a detail section through a helix;

21 shows a detail section through a helix;

22 is a rotated spiral;

23 shows a screw and a filling and pressing chamber;

24 shows a section through a reactor;

25 shows a mandrel. Fig. 1 shows the blank of a press spiral. In this spiral, the run 1, which sits on the drive shaft for fastening, is held parallel, the conveying and compression run 2 tapers conically towards the run.

Fig. 2 shows a section through a press spiral acc. Fig. 1. In this press spiral, the slope 3 is the same over the entire length 4. The space between the spiral fields 5 is the smallest on the drive side 6 and the largest on the strand side 7. During compression, the press spiral is compressed, but not evenly according to the spring constant, but reinforced on the strand side, since the batch to be compressed is partially supported on the walls of the press chamber. When compressing, the space 8 is still at least the same width or wider than the drive side. As a result, the small parts do not have to travel their way through a tapered space, which would significantly hinder their transport through the press spiral and lead to an empty turning. This version is particularly suitable for medium pressures, e.g. B. to compress Holzkieinteile to about 650 g / dm ³ .

Fig. 3 shows the cut of a press spiral for a higher compression. To increase stability, the fastening part 9, with which the press spiral is held on the drive shaft, is kept wider than the conveying run 10, to which it tapers in length 11 by approximately half a spiral revolution. The conveyor run 10 can have approximately the same length as the press run 12. This press spiral has a higher strength than that shown in FIG. 2. It is particularly suitable for higher densifications, for example of small wooden parts to about 750 g / dm ³ .

Fig. 4 shows a section through a press spiral acc. Fig. 3. In this press spiral, the slope 13 is the same over the entire length 14. The space 15 between the spiral fields 16 is the same size in the conveying area 17, in which the press spiral lies under the inlet and takes up the batch, and increases in the press area 18 towards the end 19 on the strand side. 20th

Fig. 5 shows the cutting of a press spiral for high compression. After the parallel fastening strand 20, the conveying strand 21 tapers to the size of the pressing strand 22, which in turn is parallel. The pressing strand 22 is curved in the radius 23. The wound press spiral has a uniform slope in the area of the fastening and conveying run. The slope increases continuously in the press section. The wedge-shaped taper in the conveyor run and the curved press run result in a press spiral of particularly high load capacity in which the spaces between the spiral webs expand and prevent the screw from plugging.

6 shows a longitudinal section through a horizontal extrusion tube press. The hollow drive shaft 25 is inserted into the drive gear 24. The press spiral 26 is attached to it. The extruder 27 is mixed with the mixture from the two inlet shafts 28; 28 ^' filled. Depending on the batch to be compressed, the inlet 29 can also be designed as a single or multiple shaft. The reactor 31 is gladly connected to the filling and pressing chamber 30 by EP 0 376 175. If the device processes small wooden parts, steam is introduced into the edge layer of the strand by means of the reactor. As a result, the small parts of the outer layer lose their strength and achieve a higher compression and a particularly smooth and high-strength surface, since the small parts of the inner layer push outwards for a certain time. The curing channel 32 connects to the reactor 30. The movable part 33 is pressed with clamping elements 34, in the exemplary embodiment hydraulic cylinder, against the rigid part 35 in such a way that the heating energy can get into the strand without large gap losses. The water in the batch evaporates during curing. The strand is thus increasingly becoming a barrier against the heat input into the interior. The heating or curing channel 32 can be, for example, about 70 meters long if pallets of 145 x 145 mm are extruded at a speed of 8 m / min. In order to improve the heat input, the invention provides steam zones 36 with a length of approximately 200 to 1000 mm at a distance of up to several meters. The steam penetrates through the already hardened outer layer and transports the thermal energy into the not yet hardened strand inner parts. It is more expedient and cheaper to carry out steaming in individual shorter zones than to enter steam continuously. 21

The mandrel 37 is attached to a pressure cell 38 and this to a linear motor 39, e.g. a hydraulic cylinder. The density of the strand is determined by its friction against the filling and pressing chamber 30, the reactor 31, the curing channel 32 and the immersion depth of the dome 37. The deeper the mandrel 37 projects into the strand, the higher the compression and vice versa. Since the strand wants to pull the mandrel 37, a tensile force arises which is measured with the pressure load cell 38. If the compression and thus the tensile force is too great, the linear motor 39 pulls the mandrel 37 out of the strand until the desired tensile force and compression is established. In the opposite case, if the tensile force and the compression are too low, the linear motor 39, controlled by the pressure transducer 38, allows the mandrel 37 to continue to run in the strand. Depending on the profile, it is advantageous to design the individual steam zones 36 as separate components between the individual parts of the heating duct 32, whereas with the other profiles the integration of the steam zone 36 into the heating duct 32 is more expedient.

FIG. 7 shows a cross section through an extrusion tube press on the line I-1 of FIG. 6. In the exemplary embodiment, the mandrel 40 is designed as a hexagon. This shape prevents the strand from rotating with the spiral 41. Depending on the requirements, the mandrel 39 can also be rectangular, square, oval, round or in any cross section. The extruded profile is determined by the contour 42 of the filling and pressing space 43. Since the materials used by the invention do not flow or hardly flow, a strand with a ratio of the sides 44; Realize 45 of 1: 2 without significant differences in compression. Since the different rates of incidence of the small parts into the filling and pressing space 42 play no role in the extrusion and the propulsion takes place continuously, there are no different compression zones and surfaces in the strand as can be observed in the extrusion molding with piston extrusion presses. The inlet 46 widens in the direction of the filling and pressing space 43 in a wedge shape to prevent clogging or bridging.

Fig. 8 shows a section through a vertical extrusion tube press, such as for extruding, for example, waste or recyclate small parts from expanded concrete is used. This material requires a high pressure of around 200 to 600 kp / cm ² . Therefore, a press spiral 47 according to this application. Fig. 5 chosen. In the exemplary embodiment, a press without a mandrel is selected. Of course it is also possible to use mandrels for this material. Since the batch does not require a binder that must react under heat, no heating channel is required. The strand obtains its final strength through autoclaving under steam pressure for several hours. The filling and pressing chamber 48 with the reactor 49 is made from one piece 50 in the exemplary embodiment. Of course, the invention teaches, if this is advantageous in the given case, to manufacture the device from several parts and to provide it with wearing parts. The wearing parts can be nitrided or surface coated to achieve a longer service life. Ceramic or titanium coatings have proven their worth, which at the same time reduce friction. However, all other suitable types of surface treatment are conceivable. Water, water vapor or a separating agent is brought between the strand and the inner wall 52 of the reactor from the circumferential outlet grooves 51 and thus the friction is significantly reduced. If the baling chamber is made too short, the small parts will flow, there will be double growth and the small parts will not emerge from the device as a uniformly compacted strand but at different speeds. The reactor here represents a part of the filling and pressing space and can be carried out in such a length by the introduction of release agent or water or water vapor that no double growth occurs. The compression is controlled by the braking device 53, which receives its force from the linear motor 54. In the exemplary embodiment, the filling takes place via an oscillating judge 55, which is set in motion by unbalanced motors 56, 56 '.

Fig. 9 shows a section through a vertical extrusion tube press, as it is designed for example for the production of chipboard panels or profiles for the furniture industry. In a manner already known, the press spiral 57 is connected to the drive 58 and the mandrel 59 protrudes through both. As previously mentioned, it is coupled to a pressure cell 60 and a linear motor 61 and acts as described. The filling and pressing space 62 is filled, for example, by a hopper 63 which is driven by unbalance motors 64, 64 '. 23

can be vibrated. The hopper 63 is in turn by means of conveyor spirals 65; 65 'provided with batch. The reactor 66 and the heating channel 67 connect to the filling and pressing chamber 62. The exemplary embodiment shown is particularly suitable for the aforementioned products because chipboard has only a comparatively low compression of about 500 to 550 g / dm ³ and therefore only relatively light press coils are used, which, however, must mesh, i.e. run into one another. They should therefore be built as short as possible. The vertical arrangement for profiles in the furniture industry is just as advantageous. Here a higher compression of 630 to 850 g / dm ^{2 is} required, which can be realized with one or more press spirals as shown in FIG. 3 or 5. Both products have relatively small wall thicknesses. The heating time and curing channel 67 are correspondingly short.

Fig. 10 shows a cross section through a vertical extrusion tube press at the level of the filling and pressing space. The device is designed for the extrusion of chipboard panels for door panels. The majority of these products have a width of 33 mm in dimension 68. The center distance 69 of the hexagon holes can be approximately 30 mm. With this arrangement of holes, it is necessary that the individual press spirals 70; Comb 70 "; 70" or run into each other.

Fig. 11 shows a cross section through a vertical tube press at the level of the filling and pressing space 71. The device is designed for the extrusion of profiles for furniture manufacture. In the profile 72 there are a larger hexagon hole 73, a smaller hexagon hole 74 and a square hole 75. The pressing force is through the press spirals 76; 77, 77 'and 78'.

Fig. 12 shows a cross section through an extrusion tube press, at the height of the baling chamber 79, on the pallet blocks of 100 x 145 mm are generated, the dimension 80 should correspond to the width of 100 mm and the dimension 81 to the length of 145 mm of the pallet block . The spiral 82 can have a dimension of approximately 90 mm outer diameter and 45 mm inner diameter. The dimension 83 of the width across flats of the hexagonal dome 84 can e.g. 30 mm.

13 shows a section through an extrusion tube press. The filling and pressing room 101 24

and coil 102 are shown only schematically and are discussed in more detail in the following drawings. The components of the extrusion tube press are mounted so that they can move longitudinally on a base frame 103, on the one hand to be able to set the immersion depth 104 of the spiral 102 and on the other hand to allow quick assembly and rapid disassembly and replacement of the wearing parts. The individual components of the extrusion tube press are mounted on carriages 105 to 110, which are guided in a C-profile 112 with the rollers 111. The top 113 of the C-profile 112 is designed as a rack. Each carriage 105 to 110 can be moved by means of a shaft with gearwheels 114. The press has a heating channel 115, in the exemplary embodiment two reactors 116 and 117, between which there is a first heating channel part 118 with rigid walls. The first reactor 117 is flanged to the housing 119 of the filling and pressing space 101. Spacers 121, with which the immersion depth 104 is determined, are located between the housing 119 and the drive 120. The mandrel 122 is connected via a pressure cell 123 to a displacement sensor 124, here a hydraulic cylinder. In the exemplary embodiment, the individual assemblies are flanged together with screw connections 125. The reactor 116 and the carriage 110 of the displacement sensor 124 are fixed in place by locking pins 126 and 127, while the other components of the press can move in the longitudinal direction in accordance with the thermal expansion. It has proven advantageous not to design the reactor as described in EP 03 76 175, but as a disk reactor, as explained in FIG. 24. Furthermore, it has proven to be advantageous not to manufacture the reactor in one piece but from at least two individual reactors 116 and 117 or more and heating passage elements 118 lying in between. In this embodiment it is ensured that only as much steam or water can penetrate the strand as it can absorb in the throughput time of the strand. This prevents any excessive condensation, which can wash out the binder that has not yet set from the small parts.

In or at the end of the heating duct 115, the invention provides for a speed measurement of the line. In the exemplary embodiment, a friction wheel 128 is selected with which a change in the exit speed of the strand is determined. If the tensile force on the mandrel and / or the drive power, which is measured via the current strength, increases at the same time, the displacement sensor moves 124 the mandrel 122 a piece from the press. In the opposite case, he lets it protrude deeper into the press. The invention provides for the immersion depth to be determined and changed independently using a computer. The computer only needs to be given the setpoints, which can be determined in tests. With this regulation of the immersion depth 104 and the designs of the spiral, mandrel and pressing chamber described below, jamming or spinning is reliably prevented and the compression can be determined precisely.

The immersion depth 104 of the spiral 102 can only be determined approximately in the construction of the extrusion tube press. A length of 0.3 to about 4 fronds was empirically determined, depending on the type of small parts. However, since the strand is transported into the heating duct 115 at a lower speed than corresponds to the product of the spiral speed and spiral pitch, the screw rubs against the strand being formed and the small parts between the spiral back and the inside of the press chamber. The friction energy can be a large part of the drive power and is converted into heat. A part of the heat advantageously gets into the strand and heats it, as a result of which the heat input from mandrel 122 and heating duct 115 can be reduced. However, a part gets into the spiral. Although the invention provides for the spiral to be made from hot-work steel, the heat input into the spiral must nevertheless be limited. In addition to the shape, the friction and friction is very much determined by the immersion depth 104 of the spiral. Therefore, the immersion depth 104 is brought to the absolutely necessary level with which a safe operation of the device is possible. Experience has shown that this dimension changes over time due to the wear in the filling and pressing space 101 on the mandrel 122 and on the spiral 102. The invention therefore provides spacer elements 121 with which the immersion depth 104 can be adapted. If the device processes different small parts, the change in immersion depth 104 can be replaced by displacement transducers, e.g., by replacing spacers 121, as in the exemplary embodiment. Hydraulic cylinders take place. The inlet shaft 129 widens in the usual manner in the spiral direction in a wedge shape.

14 shows a spiral with a continuously increasing slope. in the 26

In the exemplary embodiment, the profile of the helix 130 is not dealt with. This is done in the detailed drawings Fig. 17; Fig. 18; Fig. 19; Fig. 20 and Fig. 21. The spiral is preferably milled or turned from a shaft. The helix begins with the milling 131 and the slope 132. The latter increases continuously to the pitch dimension 133. The increase in the pitch per revolution can amount to approximately 1 to more than 10% of the spiral outer diameter. The coil 130 has the same width in the dimensions 134. The spiral gap begins with dimension 135 and increases like the slope to dimension 136. The inside diameter is 137 to 1 to about 15 mm larger than the corner dimension of the dome or its diameter if a round mandrel is used. In the exemplary embodiment, the spiral has an outer diameter 138 that is cylindrical.

Fig. 15 shows a spiral with changing slope. The spiral profile is also not dealt with. The slope 139 remains constant until the end of the inlet 140. The spiral width 141 is made to the same extent over the entire length. From the end of the inlet to the end of the spiral, the pitch increases from size 143 to size 144. The increase in pitch per revolution can be up to approximately 15% of the outer screw diameter. In the exemplary embodiment, the immersion depth 145 is approximately 2.5 helical revolutions. Depending on the type of small parts, the immersion depth can be 0.3 to about 4 spiral turns. The increase in the slope does not have to be continuous, but can also take place disproportionately. In general, a helical pitch of about 8 to 15 ° is chosen. However, it can be over 20 °. The decisive factor here is the slope of the last turn of the spiral. The pressing space 147 connects to the filling space 146. It extends from the dimension of the filling space 148 to the dimension 149.

The expansion depends on the immersion depth, the type of small parts and the level of compaction. It can be about 0.5 to about 5 mm. The ideal value must be determined empirically. The invention forms the part of the press chamber with the wedge-shaped extension 150 as an inserted wear part, which is easily replaceable and possibly renewable. The gap dimension 151 depends on how thick the higher-density edge zone is to be formed and by what amount the edge zone is to be compressed higher. Since the spiral rotates faster than the batch is transported, small parts squeeze into the gap 152 between the 27

Spiral 153 and the inner walls 154 of the pressing space 147. If the gap size is sufficiently small, for example between 0.2 and approximately 2 mm, and the small parts are of sufficient size, they do not get into the gap 151 or only to a small extent. On the other hand, the gap size is significant For example, larger than 5 to 15 mm, the edge zone is compressed only by a moderate amount of about 0J to 0.3 kg / dm ³ higher than the inner zone of the strand. In the intermediate range, an unfavorable value can result, which hinders the transport of the batch through the friction and friction in such a way that the compression may increase in an uncontrolled manner, without the position of the dome or the contact pressure of the heating duct being changed. The invention speaks here of an unstable compression behavior. For strands with a higher bending strength, this gap dimension should be chosen so that the small parts in the edge zone are oriented along the strand. In this area, the invention provides for the regulation of the compression by a computer which responds sufficiently quickly and reliably to changes in the compression by adjusting the immersion depth of the dome in the strand and ensures a uniform compression, as described under FIG. 13.

Of course, the change in the slope of the spiral can be advantageously combined with that described in FIG. 14. Here, the slope increases only moderately up to the end of the inlet 140 and more sharply up to the end of the spiral.

16 shows a partial section through a spiral 155 and a filling and pressing space 156. In the exemplary embodiment, the pressing space 157 is made with parallel walls 158 and 159. At the immersion depth of dimension 160, the spiral is conical along the auxiliary lines 161 and 16V. The gap dimension 162 can be about 1 to more than 10 mm larger than the gap dimension 163. Due to the taper, the small parts in the gap are compressed to a lesser extent than in the case of a spiral with a cylindrical outer dimension. The invention provides for the inner diameter 164 of the spiral 155 to be tapered in the region 160 of the immersion depth towards the spiral end 165, if necessary. The extent of the expansion can be up to about 10 mm. The latter measure reduces the frictional force acting on the mandrel 166 and facilitates the batch transport. 28

Fig. 17 shows a detail section through the profile of a helix. The helix is tapered towards the drive side 167 by the angle of dimension 168, which can be approximately 5 to 25 °. The selected incline of the spiral profile means that fewer small parts are squeezed into the gap between the spiral and the pressing chamber. Friction is reduced and batch transport is facilitated.

18 shows a detailed section through the profile of a helix in which the helix back is offset with a step 169. The width 170 of the step can be constant over the length of the spiral or decrease in the pressing direction. The latter is achieved when the spiral back 169 has a greater slope than the end face 171 of the spiral. The dimension of step 169 can be about 0.5 to more than 5 mm.

19 shows a detail section through a helix. 17 and 18 are combined in the exemplary embodiment. The conical inner spiral back 174 connects to the outer spiral back 172 in a step 173. The dimension of the step, as in FIG. 18, can be approximately 0.5 to more than 5 mm; the dimension of the angle 175 about 5 to about 25 °.

20 shows a detail section through a helix. The end face 176 on the heating duct side has a slope at an angle 177. The dimension of the angle can be up to about 25 °. It has the task of guiding the compacting small parts more inwards towards the mandrel and reducing the friction between the spiral and the pressing chamber.

21 shows a detail section through a helix. The angle 178 is reversed in the direction as in FIG. 20. In this exemplary embodiment, it has the task of guiding the compacting small parts more outwards in order to reduce the friction on the mandrel.

Fig. 22 shows a turned spiral for extrusion for smaller or thin-walled profiles. With these profiles, a wound or machined spiral, as treated in the previous figures, can be too weak to produce the compression force. For non-circular profiles such as 29

For example, door frames or various strips, there is no risk of the small parts also turning. In addition, a very small hole would only result in minimal material savings and would not be profitable due to the additional costs of an extrusion press. As with the coiled spirals, the slope 179 can be up to more than 20 °. If the spirals are turned, only a shorter inlet shaft and a lower immersion depth of 0.3 to 3 revolutions of the spiral in the press chamber are required. The spiral back 180 can also be kept thinner. Generally, a spiral slope of 5 to 11 degrees is most advantageous. The invention teaches that the turned spiral, like the wound spiral, tapers conically in the area of the baling chamber, the degree of taper being proportionately greater than in the aforementioned spirals. Likewise, the invention teaches the slope of the spirals to increase in the pressing direction. An unequal increase in the slope as previously described is also advantageous.

23 shows a screw 181 in a filling and pressing chamber 182. The pressing chamber 183 is designed as a wearing part, which can be easily replaced. It has a step 184, which can be 0.2 to approximately 2 mm all round. The task of this step-like extension and the subsequent wedge-shaped extension 185, which in turn can be 0.2 to about 2 mm, is to reduce the frictional pressure of the batch against the press space. The combination of a step-shaped and a wedge-shaped extension provides the invention not only for screws but also for turned and wound spirals. In the exemplary embodiment, the screw pitch 186 is kept the same size up to the inlet end 187. In the immersion area 188 of the screw 181 in the pressing chamber 183, the gradient increases increasingly. The cylindrical screw base 189 runs out in the immersion area to a cone tip or approximately to a tip. In a further embodiment, the invention provides for the part of the screw not only to be cylindrical up to the inlet end 187 but also with a weaker cone. In the exemplary embodiment, the screw is provided with a cooling bore 190, through which coolant flows into a return pipe 191. In the case of screws, the spiral back 192 can be kept relatively thin, since the compressive forces are essentially absorbed by the screw core tube 193. Since in principle an incline of more than 20 ° can be carried out, the invention provides for the screw not only in a catchy manner, but also for larger ones 30th

Execute diameters in multiple courses. A multi-course version has the advantage that no transverse forces occur and three-speed screws even self-adjust.

24 shows a section through a reactor, which represents a further development of EP 03 76 175. Since the spiral or screw presses according to the invention press the mixture more strongly against the outer boundary walls and compress it highly, it is advantageous to bring the steam, the water or the additional binder from the narrowest possible gaps from 0.1 to about 2 mm onto the strand prevent swelling of the small parts that have not yet set. The invention provides for the reactor to be produced from a large number of disks 194 which, when assembled, give the gap dimensions 195 of 0.1 to 2 mm. The inner contour can be made with parallel walls or widened in a wedge shape. The manufacture of a reactor according to the invention, even for more complicated extruded profiles, is relatively inexpensive since the inner contour 196 of the assembled disc bundle can be produced in one clamping by wire EDM. The reactant is supplied via bore 197 and brought out and into the strand via column 195. A ring heater 198 is provided, the temperature of which is above the flow temperature of the reactants, which largely prevents the formation of condensate. The condensate formed, particularly during start-up, is fed to a condensate separator via the bore 199.

Since the strand can only absorb a limited amount of reactant in one unit of time, since this would otherwise condense in the strand and wash the binder out of the small parts, the invention teaches to use at least two reactors with an intermediate heating part. However, a large number of reactors can also be provided if they are intended to make a significant contribution to rod hardening. Since the strand is produced on the continuously operating presses with a high degree of profile uniformity, the reactors can be arranged over the entire length of the heating channel.

25 shows a mandrel which represents a further development of DE A 198 26 408.9. The mandrel tube 200 is drawn, the inner tube 201 with the Through openings 202 and the sealing plug 203. The wedge-shaped taper 204 is approximately at the level of the immersion depth of the spiral in the pressing space. The length 205 of the taper can correspond approximately to that of the immersion depth of the spiral. The dimension 206 of the taper can be approximately 0.2 to more than 5 mm and is essentially dependent on the mandrel size, the extruded profile and the type and dimension of the small parts. The further design can acc. DE A 198 26 408.9.

The components described in the exemplary embodiments are combined to the most advantageous result for the respective application. Other designs, not shown, acc. the general idea of the invention is expressly provided.

Claims

32 patent claims

1. A method for the continuous extrusion or extrusion of a batch of small parts, in which at least part of the batch to be pressed is conveyed by a screw-like winding conveying path which is formed by a rotatingly driven spiral or spindle element, the spiral or spindle element being designed in such a way that that the cross section of the conveying path increases in the conveying direction.

2. Processors according to claim 1, characterized in that the pressing force is generated by one or more spirals which have a predetermined in particular non-uniform slope and taper in the strand direction or are curved in the development that the distances between the spiral courses even under workload stay the same towards the strand or enlarge.

3. The method according to claim 1 or 2, characterized gekennzeichent that a mandrel is passed through the press spiral in the strand during extrusion and the depth with which the mandrel protrudes into the strand is controlled controlled to control the compression of the batch.

4. The method according to any one of claims 1 to 3, characterized in that two or more press spirals are stored one in the other, which have a different length and are adapted in their different conveying speed in such a way that no duplication occurs,

5. The method according to claim 3, characterized in that the tensile force is measured on the mandrel and the immersion depth of the mandrel in the strand is adjusted by a manual or automatic control to the desired compression of the strand.

6. The method according to any one of claims 1 to 5, characterized in that round, non-circular square, square or polygonal or non-circular trained 33

Dome are used to prevent excessive rotation of the strand with the spiral.

7. The method according to any one of claims 1 to 6, characterized in that the dimensions of the profile to be generated corresponding to one, two or more press spirals are used, which are arranged spaced apart or mesh with each other.

8. The method according to any one of claims 1 to 7, characterized in that two or more spirals run into one another in the same or opposite directions with the same or different conveying speed and that the respective inner spiral protrudes by 1/2 to 8 spiral turns from the outer spiral to prevent a Dual growth.

9. The method according to any one of claims 1 to 8, characterized in that a reactor acc. EP 0 376 175 is used, liquid or vapor release agent or water or water vapor being brought between the reactor walls and the strand through this reactor in order to reduce the friction, wear and tear or tendency towards twofold growth.

10. The method according to claim 9, characterized in that the entry of water or steam not only from the reactor but in one or more sections at intervals from each other also takes place from the walls of the heating channel, such that the agent introduced into the strand during curing evaporated water is replaced in whole or in part and serves as a carrier medium for further introduction of the thermal energy into the strand.

11. The method according to any one of claims 1 to 10, characterized in that the small parts are compressed with a higher humidity of 0.5 to 60% dry (absolutely dry) to reduce the required pressing force.

12. A device for performing the method according to claims 1 to 11, characterized in that a spiral or to compress the strand 34

Spindle is provided with a spatially tortuous conveying path which increases in cross section towards the end on the strand side.

13. The apparatus according to claim 12, characterized in that the press spiral is made of a rod material or wire tapering towards the strand side.

14. The apparatus according to claim 12, characterized in that the press spiral is wound from a sheet which is parallel in the area of the attachment for the drive and tapers in a wedge shape towards the strand.

15. The apparatus according to claim 11, characterized in that the press spiral is forged.

16. The device according to one of claims 12 to 15, characterized in that the press spiral in the area of the attachment for the drive has substantially parallel wall sections and tapers in the length of 1/8 to 1 1/2 spiral turns to the extent of the conveying strand and the subsequent press run tapers further to about 7/8 to 1/5 the width of the feed run towards the end on the strand side.

17. Device according to one of claims 12 to 16, characterized in that the press spiral has a uniform slope.

18. Device according to one of claims 12 to 17, characterized in that the spiral is made of a sheet metal or a forged part which is curved entirely or only in the pressing section.

19. Device according to one of claims 12 to 18, characterized in that the spaces between the spiral webs in the working state to the strand are the same size or enlarge. 35

20. Device according to one of claims 12 to 19, characterized in that the press spiral has an increasing slope to the strand end.

21. Device according to one of claims 12 to 20, characterized in that two or more spirals lie one inside the other and that the respective inner spiral protrudes by 1/2 to 8 spiral turns over the strand-side end of the respective outer spiral.

22. Device according to one of claims 12 to 21, characterized in that mandrels are used for extrusion molding.

23. The device according to claim 22, characterized in that the mandrels have a round, rectangular, square or polygonal cross section.

24. Device according to one of claims 12 to 23, characterized gekennzeichent that the force with which the strand wants to pull the mandrels is measured and a control the penetration depth of the mandrels into the strand to control the compression manually or automatically, by means of a linear motor , is made.

25. Device according to one of claims 12 to 24, characterized in that the mandrel or the mandrels are rigidly attached in the strand direction.

26. The device according to any one of claims 12 to 25, characterized in that the filling and pressing space in horizontal extrusion presses is filled via a single-, two- or multi-channel inlet shaft and that each shaft widens towards the filling and pressing space.

27. The device according to one of claims 12 to 26, characterized in that the filling and pressing space is filled via a movable hopper in vertical presses.

28. Device according to one of claims 12 to 27, characterized in that a reactor according to the filling and pressing room. EP 0 376 175 then closes 36

which water, water vapor or liquid or vaporous binder is introduced into the edge zone of the strand.

29. Device according to one of claims 12 to 28, characterized in that the filling and pressing chamber at its outlet end as a reactor. EP 0 376 175 is formed.

30. Device according to one of claims 12 to 29, characterized in that a liquid or vapor release agent is brought from the rector between its inner wall and the strand.

31. The device according to one of claims 12 to 30, characterized in that a heating duct connects to the reactor and from which in several sections of about 100 to 1000 mm in length at intervals of about 0.5 to 20 meters of water or water vapor in the Strand is introduced.

32. Device according to one of claims 12 to 31, characterized in that during extrusion without mandrel, the density of the strand is determined by a brake after the reactor and / or by the contact force of the movable heating duct part against the rigid heating duct part.

33. Device according to one of claims 12 to 32, characterized in that several spirals are used which are either parallel to each other or intermeshed in the device and have the same or opposite direction of rotation.

34. A method of extruding or extruding a batch of small parts for the production of a profile in which the batch is compacted by at least one spiral or screw in a press room, characterized in that the degree of compression by controlled axial positioning of the spiral or Auger and / or a coaxially arranged to the spiral axis mandrel relative to the press chamber and / or a change in the strand braking forces is controlled 37

35. The method according to claim 34, characterized in that

- The spiral or screw protrudes into the baling chamber at such an adjustable depth that the highest possible compression with the setting is 5 to 15% above the desired compression and thus the latter is reliably achieved, and / or

- The width of the spiral of the spirals or the back of the screw is largely constant, while the pitch increases in the pressing direction, and / or

the pressing space widens in a wedge shape in the pressing direction, approximately in the length of the immersion depth of the spiral or screw, and / or,

- The press room at the end of the inlet shaft increases in one or more stages, and / or

- The spiral or screw back in the pressing direction increases in diameter so that the small parts between the spiral or screw only densify by a desired amount higher than the small parts within and not to the highest possible degree of compression, and / or

- The spiral or screw tapers conically in its depth of immersion in the press chamber,

the spiral in the inner diameter widens conically in the immersion depth in the press space,

the screw base is conically reduced in the depth of immersion in the press chamber,

the mandrel tapers in a wedge shape approximately in the length of the immersion depth of the spiral in the press space,

- That the exit speed of the strand, the power consumption of the drive and the tensile force on the mandrel measured, the values processed in a computer and by this the immersion depth of the mandrel in the strand is constantly adjusted to achieve and keep the desired compression.

36. The method according to claim 34 or 35, characterized in that the gap between the spiral and filling and baling chamber is kept so small that no or only so few small parts get into the gap that there is no self-increase in compression and stuck and turning empty Device results.

37. The method according to claim 35, characterized in that the gap between the spiral and screw is kept so large that the small parts in the gap only around a limited amount is compressed up to about 30% higher than the internal small parts and there is no self-increase in compression and the device becomes stuck and turned empty.

38. The method according to claim 35, characterized in that the gap between the spiral or screw is made so large that the small parts in the gap lie parallel to the pressing direction and the compression would increase automatically without changing the pressing parameters and by a controlled longitudinal movement of the As far as possible, the mandrel must be kept constant at the desired compression level.

39. The method according to the preceding claims, characterized in that a mandrel acc. DE 198 26 408.9 is used and the mandrel tube, the strand and the spiral are cooled by the heating medium and / or the addition of water in their temperature to the permissible level.

40. Device for performing the method according to claims 35 to 39, characterized in that a control device is provided for moving the spindle or spiral and / or the mandrel element in the axial direction in accordance with a predetermined compression of the batch.

41. Apparatus according to claim 40, characterized in that the helix width is the same over the spiral length and / or the pitch of the spiral increases uniformly with each revolution in the pressing direction, by about 1 to about 10% of the spiral diameter.

42. Device according to one of claims 40 or 41, characterized in that the gradient of the spiral in the pressing direction up to about the end of the inlet shaft increases uniformly with each revolution, by 0.5 to about 5% of the spiral diameter and approximately in the area of the immersion depth enlarged in the press room by an amount of about 2 to about 15% of the spiral diameter.

43. Device according to one of claims 40 to 42, characterized in that the pitch of the spiral in the pressing direction increases unevenly, but more and more up to an amount of about 25% of the diameter, or that the spindle is initially designed with the same pitch and with a larger pitch in the pressing chamber.

44. Device according to one of claims 40 to 43, characterized in that the spiral back has a slope of about 5 ° to about 25 ° in the pressing direction.

45. Device according to one of claims 40 to 44, characterized in that the spiral back in the pressing direction has a step of 0.2 to more than 5mm, which protrudes outward in the spiral diameter.

46. Device according to one of claims 40 to 45, characterized in that the step is made with the same pitch as the spiral.

47. Device according to one of claims 40 to 46, characterized in that the step has a greater slope than the spiral and the width of the coil with the larger diameter decreases in the pressing direction.

48. Device according to one of claims 40 to 47, characterized in that the step and the slope are combined in the spiral cross section.

49. Device according to one of claims 40 to 49, characterized in that the largest diameter of the spiral is about '0.2 to about 2mm smaller than the smallest dimension between two surfaces at the beginning of the press space and thereby a thin, higher density Edge zone of the strand results, the compression of which does not increase by itself without changing the compression parameters until the spiral turns.

50. Device according to one of claims 40 to 49, characterized in that the largest diameter of the spiral is smaller by more than about 5 mm than the smallest dimension between two surfaces at the beginning of the press space and thereby a thicker, compared to the inner zone by to about 30% more compressed edge zone, which does not self, without changing the compression parameters 40

elevated.

51. Device according to one of claims 1 to 50, characterized in that the spiral is designed in its largest diameter so that the small parts of the surface layer are oriented parallel to the pressing direction and that the compression would increase automatically without changing the compression parameters, this but prevented by a computer-controlled immersion depth of the mandrel in the strand and the pressing force of the movable walls of the heating channel and the compression is kept to a largely constant, determined and variable extent.

52. Device according to one of claims 40 to 51, characterized in that the end face of the helical cross section is at an acute angle up to about 65 ° in the pressing direction of the strand and the small parts directed more to the outside during compression to reduce the friction between strand and mandrel become.

53. Device according to one of claims 40 to 52, characterized in that the end face of the helical cross-section is at an obtuse angle up to about 105 ° in the pressing direction of the strand and thereby the small parts directed more inward during compression to reduce the friction between strand and baling chamber become.

54. Device according to one of claims 40 to 53, characterized in that the end face of the helical cross-section has a protruding into it with an angle of greater than about 100 °.

55. Device according to one of claims 40 to 54, characterized in that the immersion depth of the spiral in the pressing space is changeable about '0.3 to about 4 revolutions and the immersion depth is adjusted and adjusted with spacers or displacement sensors.

56. Device according to one of claims 40 to 55, characterized in that the wound spiral is cylindrical in the inner diameter and the 41

Internal diameter to the mandrel has a gap between about 1 and about 10 mm.

57. Apparatus according to claim 55, characterized in that the spiral is cylindrical up to about the height of the inlet end and tapers conically in the pressing direction by up to about 10 mm.

58. Apparatus according to claim 55, characterized in that a spiral turned from a flat steel or correspondingly machined from round material produces the compression force.

59. Device according to one of claims 40 to 58, characterized in that the compression is carried out by a screw with a cylindrical screw base, the helical design of which corresponds to the spiral described.

60. Apparatus according to claim 59, characterized in that the screw base is cylindrical up to approximately the level of the inlet end and is designed as a cone tip or truncated cone towards its end on the press chamber side.

61. Apparatus according to claim 60, characterized in that the worm is of one, two or more threads.

62. Device according to one of claims 40 to 61, characterized in that the spiral or worm is made of hot-work steel with a particularly smooth surface that is treated for wear and / or friction, such as, for example, nitrous or titanium oxide coating.

63. Device according to claims 40 to 62, characterized in that the compression force is generated by a turned spiral and that the change in the slope and the outer contour of the turned spiral corresponds approximately to that of the wound spiral.

64. Device according to one of claims 40 to 64, characterized in that a mandrel acc. DE 198 26 408.9 is used. WO 99/48676, -, PCT / EP99 / 01987

42

65. Apparatus according to claim 64, characterized in that the mandrel tapers in cross section by about 0.2 to about 5 mm

66. Apparatus according to claim 65, characterized in that the tapering of the mandrel takes place approximately at the level of the baling chamber or a bit behind.

67. Device according to claims 40 to 66, characterized in that one or more reactors acc. EP 03 76 175 can be used.

68. Apparatus according to claim 67, characterized in that there are rigid heating channel parts between the reactors.

69. Apparatus according to claim 68, characterized in that the reactor consists of a plurality of disks, between which there are steam exit gaps of about 0.1 to about 2 mm to the strand, in the assembled state.

70. Apparatus according to claim 69, characterized in that the reactant is fed through an overhead bore and any condensate formed is fed through a bore below into a condensate separator.

71. Device according to claims 40 to 70, characterized in that the mandrel displacement sensor, the drive and the conveying element, the filling and pressing chamber, the reactors and the rigid heating channel parts are mounted on longitudinally movable carriages and are connected to one another, for example by screw connections.

72. Device according to one of claims 40 to 71, characterized in that the displacement sensor determining the immersion depth of the mandrel is controlled by a computer which processes the data of the exit speed of the strand, the drive power and the tensile force on the dome.

73. Device according to one of claims 40 to 72, characterized in that the pressing space widens in the pressing direction by about 0.3 to about 5 mm in a wedge shape. 43

74. Device according to one of claims 40 to 73, characterized in that the pressing space expands in relation to the filling space in one or more stages by approximately 0.2 to approximately 5 mm.

75. Device according to one of claims 40 to 74, characterized in that a step-shaped and a wedge-shaped extension of the press space are combined.