EP3385047B1 - Extrusion device and method for manufacturing extruded products - Google Patents

Description

The invention relates to an extrusion device and a method for producing extruded products with the features in the independent claims.

the DE 10 2006 055 116 A1 discloses an extrusion device and a method for producing extruded blocks from small plant parts, in particular small wood parts, which are provided with a thermoreactive adhesive which is cured essentially with steam. The extrusion device has an extruder with a press channel adjoining in the pressing direction, in which the strand is heated and cured by means of a steaming device. At or in front of the steam supply, the strand can be additionally heated conductively from the outside via heated duct walls. A cooling section connects to the steaming device.

Another extrusion technique is from the WO 2011/029923 A1 famous. The small wood parts provided with a thermosetting binder are pressed in an extruder into a rod-shaped strand, which is then steamed in a press channel and then cured in a cooling channel. During steaming, the heat required for curing is essentially introduced into the strand via the steam and its enthalpy of condensation. The subsequent heating of the strand in the press channel prevents the strand from cooling down prematurely and only maintains the temperature level brought about by the steaming and condensation for the duration the curing upright.

the EP 2 386 394 A1 deals with liquid, sugar-containing binders for boards made of small wood parts, which are pressed by heated press plates and set by means of conductive heat supply.

It is the object of the present invention to provide an improved extrusion technique.

The invention solves this problem with the features in the independent claims.
The claimed extrusion technology, ie the extrusion device, the associated method and an extrusion plant, and the extruded product have various advantages.

The combined heating and application of the rod-shaped strand with steam and with high-frequency electromagnetic alternating fields of a High-frequency heating has process engineering advantages. The steaming device and the high-frequency heating can optimally complement each other with regard to the energy balance and the moisture, in particular the water content, in the strand. They work synergistically and can be optimally coordinated to achieve various desired effects. The combined heating with steam and high-frequency alternating electromagnetic fields can be used to produce a hardened strand with an advantageous internal structure and particularly favorable strength values. The internal structure of the strand and the extruded product can be homogeneous or deliberately inhomogeneous. Inhomogeneities can be created, for example, by targeted displacement of the binder using a burst of steam. As a result, local binder concentrations with stronger strand consolidation, for example on the outer circumference and / or on the outside of a pin hole, can be formed.

The high-frequency heating ensures a high surface quality of the strand. The strand surface is smooth and not very porous. Overhardening of the binder due to excessive contact heat can be avoided. If the strand is moistened evenly, the high-frequency heating can also cause the strand to be heated evenly.

Small-scale concentrations of the binding agent in the pressed material and an appropriate addition technique are also beneficial. Here, the high-frequency heating can have a particularly good effect and ensure targeted curing without significantly affecting the surrounding small parts. The binding agent can form a strength-increasing support or network structure in the pressed material.

The density of the strand can be kept low because the better and more uniform curing of the possibly crosslinked binder significantly contributes to the required strength. The high-frequency heating is also advantageous for this. In addition, the input humidity of the small parts of the plant can be selected to be relatively high, which simplifies their preparation and drying and makes them cheaper.

For high frequency heating to be effective, a binder with a high electrical conductivity can be selected, e.g. an acidic binder.

The frequency range of the high-frequency heating can be above 1 MHz, preferably above 3 MHz. A frequency range between 20 MHz and 30 MHz is favorable.

The vaporization device and the high-frequency heating can be combined with one another in different ways. The steaming device is located in connection with a molding channel of the extrusion press. The high-frequency heating can be arranged in the pressing direction before or after the vapor deposition device. It can also be located in front of and behind the steaming device. Different effects can be achieved through these arrangements.

The interaction of the steaming device and the high-frequency heating means that the total heat required for curing the binding agent in the strand can be divided between the two heating processes. The two heating processes can be coordinated and benefit from each other. The jointly introduced amount of heat can be matched and limited to the amount required for curing. Excess heat and excess steam can be dispensable.

With the high-frequency heating, the binding agent in the pressed material can be heated up quickly and in a targeted manner. With the vaporization device and the enthalpy of condensation, the amount of heat required to heat the entire strand cross-section can be introduced cost-effectively and efficiently and made available for the further course of curing.

A high-frequency heater connected upstream of the vaporization device in the pressing direction can preheat the material to be pressed located in the area of the molding channel and, through the beginning of hardening, form a pre-solidification of the material to be pressed for the subsequent vaporization. The high-frequency heating primarily and quickly heats the granulated or liquid binding agent distributed in the pressed material and in the still unconsolidated strand. The small vegetable parts have an optimized input moisture, so that the high-frequency heating works primarily on the binding agent and heats it up in a targeted manner and much faster than the small vegetable parts. Local concentrations of the binder, which are primarily and very intensively heated and correspondingly solidify more quickly, can have a favorable effect. This allows local strength concentrations and bridge-like connections to be created in the pressed material. Such local binder concentrations can advantageously be achieved in a feed device designed as a mixer.

The pre-consolidation of the pressed material in the strand has the advantage that the binder retains its local arrangement and distribution in the strand during the subsequent steaming process. The amount of steam and the enthalpy of condensation as well as the steam temperature and the steam pressure can be reduced by preheating. In this way, the moisture or amount of water introduced during steaming can also be reduced. This is to achieve low humidity values or for faster achievement of a predetermined residual moisture in the extruded product produced at the end of an advantage.

To start the hardening of the binder, it is beneficial to act at a certain temperature over a certain period of time, e.g. from 110 - 150 ° C for about 10 seconds. The hardening can be started highly effectively and with a concentration of energy on the binder through the high-frequency heating. The steaming device and the condensing steam bring the thermal energy required to continue the hardening into the strand. The steam can be relieved from the start of curing and can therefore have a lower temperature and pressure. This reduces its mechanical effects on the material to be pressed.

The downstream connection of high-frequency heating compared to the steaming device has the advantage that the steam introduces additional moisture into the pressed material and into the strand, which is essential for an optimal effect of the high-frequency heating and for the fast heating of the pressed material, which acts across the entire strand cross-section, and for solidification of the binder is advantageous. A downstream high-frequency heating can also have advantages for the aforementioned gentle start of the curing process. On the other hand, the high-frequency heating can also quickly evaporate and excrete the moisture that has been introduced.

The extrusion technology claimed can be used successfully with the most varied types of binders. When using conventional binders, for example melamine resins, phenolic resins, urea resins or the like, an improved binding effect with reduced evaporation of highly volatile organic substances can be achieved. The high-frequency heating can and can bind these substances reduce their discharge under the influence of steam.

Organic binders based, for example, on starch and / or sugar and / or other carbohydrates and / or lignin are particularly advantageous. They can be heated particularly well with steam and with high-frequency alternating electromagnetic fields. There are particular advantages with binders that excrete water or other liquids during curing or polymerization, e.g. in a Maillard process. This is where high-frequency heating can work particularly well and effectively. Because of this separation from the binder, on the other hand, the amount of steam can be adapted, in particular reduced. Another advantage of such preferably organic binders is the avoidance of unfavorable later vapors, in particular of formaldehyde or other synthetic substances.

The extruded product can be in any form, e.g. as a block, strip, disk or the like. It is suitable for pallets, but also for furniture and other parts in the home.

Further advantages of the claimed extrusion technology are the acceleration and shortening of the extrusion process and the hardening of the binding agent. In this way, on the one hand, the performance of the extrusion technology can be increased and, on the other hand, its space requirement, in particular the length in the pressing direction, can be reduced. The extrusion technology claimed is therefore particularly efficient and also offers advantages in terms of reducing space and construction costs.

In addition, the extruded products can be used better and in a wider range of applications. Special advantages also result in connection with a compartment separation technology, in which a strand can be divided into several extruded products with smaller cross-sections in an economically advantageous manner by means of one or more cross cuts. This is particularly favorable with regard to the producibility of complex and, in particular, curved outer contours of these products through the shaping in the die or in the shaping channel of the extrusion press.

The extrusion technology claimed is a technical and economically independent unit. It can be installed in the initial equipment of an extrusion press or, if necessary, retrofitted or retrofitted. In particular, an existing extrusion press can be supplemented with steaming by an additional high-frequency heater. The aforementioned advantages of extrusion technology also have an effect on an extrusion plant that can contain a press material preparation with one or more additional components. This can be, for example, a single-stage or multi-stage comminution and drying of parts of plants, in particular pieces of wood or other particles generally containing lignocellulose. Furthermore, the comminuted particles can be sifted, classified and stored according to different sizes and, if necessary, mixed again. The extrusion technology claimed is particularly beneficial for specifying the initial moisture content of the small plant parts and the associated drying costs.

Further advantageous refinements of the invention are specified in the subclaims.

The extrusion technology claimed can also have the following features individually or in any combination. The high-frequency heating of the extrusion device can be arranged upstream and / or downstream of the steaming device in the pressing direction.

In one embodiment of the extrusion device, the internal dimensions of the high-frequency heating can be adjusted and adapted to different extrudate shapes.

The extrusion device can have a curing or cooling channel adjoining the heating device and optionally a separating device for the strand, in particular a compartment separating device.

The strand can harden in the hardening or cooling channel. The temperature level introduced with the vapor deposition and the high-frequency heating can be maintained for the duration of the curing process. If necessary, heat can be supplied to the strand. The function can be the same as in the prior art mentioned at the beginning.

The extrusion device can have a control and a measuring device for the strand and / or the extruded products.

In one embodiment of the method, the strand can be produced with a chamfered and / or curved outer contour and then separated, the strand having a given cross-sectional area and being separated into several individual extruded products, in particular blocks and / or strips and / or discs, with a smaller cross-sectional area and is divided. The aforementioned compartment separating device can be used with advantage for this purpose.

Figur 1:

eine Strangpressanlage mit einer Strangpresseinrichtung mit Zugabeeinrichtung, Bedampfungseinrichtung und Hochfrequenzheizung in einer schematischen Ansicht,

Figur 2:

eine Variante der Strangpresseinrichtung von Figur 1,

Figur 3 bis 5:

verschiedene Varianten in der Formgebung eines Stranges und der Bildung von mehreren Strangpressprodukten durch Abteilen des Strangs mit mehreren Trennschnitten,

Figur 6:

ein Querschnitt durch eine Hochfrequenzheizung und den dortigen Bereich des Pressenkanals und

Figur 7:

eine schematische Schnittansicht einer im Innemaß verstellbaren und an unterschiedliche Strangformen anpassbaren Hochfrequenzheizung.

The invention is shown schematically and by way of example in the drawings. Show in detail:

Figure 1:

an extrusion plant with an extrusion device with feed device, steaming device and high-frequency heating in a schematic view,

Figure 2:

a variant of the extrusion device from Figure 1 ,

Figure 3 to 5:

different variants in the shaping of a strand and the formation of several extruded products by dividing the strand with several separating cuts,

Figure 6:

a cross-section through a high-frequency heater and the area of the press channel there and

Figure 7:

a schematic sectional view of a high-frequency heater which is adjustable in internal dimensions and can be adapted to different strand shapes.

The invention relates to an extrusion device (4) and an extrusion method for producing extruded products (14). The invention also relates to a heating device (8) and a heating method in extrusion technology, which have independent inventive significance and which provide a combination of a steaming device and a high-frequency heater (10). The invention also relates to a Extrusion plant (1) with one or more extrusion devices (4) and an associated method. The invention also relates to the extruded product (14).

In the Figure 1 The extrusion plant (1) shown comprises a preparation (3) for the small plant parts and an extrusion device (4). The extrusion device (4) is used to produce a rod-shaped, extruded and quasi-endless strand (2). Extruded products (14), for example pallet blocks or other blocks, strips, discs or the like, can be produced from the strand (2).

The extrusion device (4) contains an extruder (6) with a press channel (7) connected in the pressing direction (18) and the feed direction of the strand (2) and a heating device (8) acting here on the strand (2). The extrusion device (4) can also have a separating device (13) connected to the press channel (7). Furthermore, an addition device (5) for a binding agent connected upstream of the extruder (6) can belong to the extrusion device (4). Furthermore, a control (29) and a measuring device (30) can be present.

The strand (2) consists of small plant parts, in particular small wood parts, which are provided with a binding agent. The small parts of plants are in particular small parts containing lignocellulose. They can have a fiber structure.

The binder can harden with the supply of heat in the heating device (8). The binder is preferably an organic binder and can, for example, be based on starch, sugar, lignin or the like. It can be a organic binder can be used, which separates water or another liquid during curing or polymerization. This deposition can take place in a Maillard process. Such a Maillard binder is preferably used.

The binding agent can be added to the small plant parts in a feed device (5) explained below. The small plant parts and the supplied binding agent together form the pressed material from which the strand (2) and the extruded product (14) are produced.

In the Figure 1 schematically indicated processing (3) can have several components. These can be shredding devices, a drying device, a device for sifting and classifying small parts as well as storage and also a mixing device for mixing different small wood parts as required.

The preparation (3) has a provision for the small wood parts. These can be produced externally or on site. The small plant parts are produced, for example, by crushing a wood material, drying, sifting and classifying the small parts. The wood starting material is preferably first roughly chopped, then dried in a drying device, in particular a belt dryer or drum dryer, then finely chopped and sifted and classified according to size and nature. The small parts can then be cached separately depending on their size. The different particle sizes can be mixed in a composition suitable for the strand (2). The mixture can be fed to the feed device (5) via a small parts feeder (15) and then further to the Extruder (6) are fed.

The extruder (6) presses and conveys the strand (2) continuously or intermittently in the extrusion direction (18). It has a press unit with a press member (17), e.g. a screw or a reversing press ram, and a drive (16), e.g. a hydraulic cylinder. The small plant parts are fed via a filling station (20) and metered into a filling and pressing chamber of the extruder (6). They are then pressed by the pressing member (17) in the extrusion direction (18) into a preferably cooled molding channel (21) with a shaping, preferably rigid wall. The molding channel (21) can have a channel shape that widens conically in the extrusion direction (18).

The strand (2) is given its outer contour in the molding channel (21), which is also referred to as the recipient. The strand (2) can be formed from massive across its cross section. The strand (2) can alternatively be hollow on the inside and can have one or more axial inner hollow channels, which are produced, for example, by a pressing mandrel in the extrusion press (6). Figure 3 shows such a strand formation.

The shaped strand (2) then reaches a heating device (8) in the pressing direction (18), in which the hardening of the binding agent in the strand (2) is activated by the supply of heat to the strand (2). The heating device (8) can connect to the molding channel (21) in the extrusion direction or the feed direction (18). It can also overlap with the end of the molding channel (21) on the outlet side.

The strand (2) is transported in a press channel (7) surrounding the circumference. The heating device (8) can be part of this press channel (7) and a Have channel-side interior. A curing or cooling device (12) can be connected to the heating device (8) in the extrusion direction (18). This can also be part of the press channel (7). These components of the extruder (6) can be arranged on a common machine frame (19).

The heating device (8) acts on the strand (2) and has a steaming device (9) and a high-frequency heater (10). The steaming device (9) acts on the strand (2) with hot steam, which consists, for example, of water or another suitable fluid and which condenses in the strand (2) and heats the strand material or pressed material with its enthalpy of condensation. The steam can be saturated steam or superheated steam, which is fed from a steam generator (not shown) to the steaming device (9) via one or more steam lines. The vapor pressures and temperatures generated depend on the small part material, the strand dimensions, in particular the strand diameter, the applied strand volume and other requirements and can vary accordingly. The steam can only be fed to the strand during the pauses when the strand is fed intermittently. Alternatively, it can be fed permanently.

The steaming device (9) can supply the steam to the strand (2) from the outside and / or from the inside. External feed is possible, for example, through feed openings in the duct wall. An internal feed can be made via one or more pole press mandrels. The length of the steaming device (9) and the path for introducing the steam in the pressing direction (18) can depend on the feed length in the case of the preferably intermittent feed of the strand. You can have two, three or more such stroke lengths accordingly.

The vapor deposition is preferably carried out in the region of the maximum density of the strand (2). In the case of external vapor deposition, the extrusion device (9) can have essentially rigid channel walls. A tensioning device can offer a preset contact pressure and allows radial evasion in an emergency. The steam is preferably produced externally and supplied to the steaming device (9) from the outside.

The heating device (8) also has a high-frequency heater (10). This can be present individually or several times. The high-frequency heater (10) can be arranged in front of and / or behind the steaming device (9) in the extrusion direction (18). The high-frequency heater (10) can be arranged in the immediate or near and possibly shielded connection to the vapor deposition device (9). Alternatively or additionally, a high-frequency heater (10) can be arranged after the curing or cooling device (12) and before the separating device (13). The high-frequency heating (10) is also integrated in the press channel (7). In Figure 1 and 2 various arrangements of a high-frequency heater (10) are shown.

The vaporization device (9) is preferably present individually and is arranged in the direct or close connection area to the molding channel (21). In the embodiment of Figure 1 the high-frequency heater (10) is arranged in the pressing direction (18) behind the steaming device (9), which in turn directly adjoins the molding channel (21) or overlaps it. In the variant of Figure 2 a high-frequency heater (10) is connected upstream of the vaporization device (9) in the pressing direction (18) and another high-frequency heater (10) is connected directly downstream. Figure 2 also shows the alternative or additional possibility of a High-frequency heating (10) to be arranged at a greater distance after the steaming device (9) and shortly before the separating device (13).

Figure 2 also illustrates the possibility of arranging an evaporation device (11) on the press channel (7) at one or more points. This is arranged, for example, after the second high-frequency heater (10). As an alternative or in addition, it can be arranged elsewhere, for example between the steaming device (9) and the high-frequency heater (10). In the variant of Figure 2 the first high-frequency heater (10) is arranged in the connecting or overlapping area of the molding channel (21). The steaming device (9) follows in the pressing direction (18).

The high-frequency heater (10) applies high-frequency alternating electromagnetic fields to the strand (2), which penetrate the strand (2) and heat the material to be pressed. As Figures 6 and 7 To illustrate, the high-frequency heater (10) has one or more field generators (25) which can be arranged on one side or opposite one another on the strand (2). One or more field generators (25) can be arranged on the top and / or underside of the strand (2), alternatively or additionally a one-sided or bilateral arrangement of field generators (25) on the upright sides of the strand (2) is possible. The high-frequency alternating electromagnetic fields can be, for example, electromagnetic waves, in particular microwaves. These can be generated, for example, by time-of-flight tubes such as klystrons, traveling wave tubes or magnetrons. Alternatively, other generation options are available. Field generators (25) for microwaves can be arranged on one side of the strand (2), with a reflector, for example a metal surface, being present on the opposite side.

It is also possible to generate high-frequency alternating electromagnetic fields in other ways, for example by means of electrodes arranged on both sides of the strand (2) which are connected at a high frequency. The electrodes or other electrical conductors form in the illustrated embodiments of FIG Figures 6 and 7 the field generators on both sides (25).

The field generators (25) are according to Figure 7 connected via lines to a supply device (26). The supply device (26) can be controllable. It can be connected to a control (29) of the extrusion press (6) or extrusion device (4), which is explained below. The supply device (26) can supply the required power, in particular electrical power, to the field generators (25) in a controlled manner. A specific connection and disconnection of field generators (25) is also possible here.

The one or more field generators (25) can be in one piece and each act on the strand (2) in the entire desired area. The field generators (25) can extend in the longitudinal direction of the strand (2) and can form the channel wall of the press channel (7) or be assigned to it. The length of the area of application of a high-frequency heater (10) on the strand (2) can be matched to the stroke length in the case of an intermittent strand feed and can correspond to one, two or more stroke lengths. The high-frequency heater (10) can act on the strand (2) during standstill times or breaks with an intermittent strand feed. Alternatively, it can act on the strand (2) permanently and during the strand movement.

A field generator (25) can according to Figures 6 and 7 be segmented. It can be divided into several generator modules that are lined up in the extrusion direction (18) and / or in the transverse direction. These generator modules can be switched individually. Insulation (27) can be arranged between the generator modules.

The field generators (25) can form the duct wall and can be in direct contact with the strand (2). Alternatively, a field generator (25) can be preceded by an adapter (28). This is located between the strand (2) and the field generator (25) and makes contact with the strand (2). It can be adapted to the outer contour of the strand (2), in particular it can be designed to be complementary with its contact surface. The adapter (28) is permeable to the high-frequency electromagnetic field. The adjustment means (28) can be exchangeable. It allows the high-frequency heater (10) to be adapted to different strand shapes, in particular strand cross-sections.

The press channel (7) can be rigid or movable. This design can also be present in the area of the heating device (8) and the cooling or curing device (12). A flexible design is advantageous for an intermittent strand feed. It can hold the strand (2) in the pressing phase during the initial compression of the pressed material during the initial compression and transport of the pressed material contained in the filling and pressing chamber of the extrusion press (6) and release it for the strand feed in the last area of the pressing phase. In the subsequent standing phase, the wall of the press channel (7) can again rest against the strand (2). The press channel (7) can have one or more fixed channel walls (22) and one or more movable channel walls (23) that can be brought to the line (22) and can be pressed on on one or more sides. exhibit. The movable channel walls (23) can be acted upon by a controllable adjusting device (24) which has, for example, cylinders or other suitable drive and adjusting means. Figure 6 shows such an arrangement. The movable duct wall (23) can be formed, for example, by a field generator (25) and optionally an upstream adapter (28).

The high-frequency heater (10) can also be adjustable in internal dimensions or in channel dimensions and can be adapted to different strand shapes. Figure 7 illustrates such an arrangement that allows adaptation to strands (2) of different widths. Here, for example, a segmented field generator (25) with a plurality of field modules is arranged on the upper and / or lower side, with the modules being able to be matched to the varying strand widths while being divided. The one lateral channel wall (22) can be arranged in a fixed manner. It can, for example, be designed as an insulation (27) or have one. The other lateral channel wall (23) can be movable and connected to an adjusting device (24). The movable channel wall (23) can also be designed as an insulation (27) or be provided with such an insulation. Said insulation (27) shields against the high-frequency alternating electromagnetic fields. It can be arranged several times and at suitable points on the high-frequency heater (10).

The adding device (5) can be designed in different ways and can add the binding agent to the small wood parts in different ways. The feed device (5) can be designed, for example, as a mixer, in particular as a drum mixer, which picks up a predetermined amount of small plant parts and binding agent and mixes them with one another by means of a suitable movement and releases them again at the outlet. A mixer can be local, pearl-like Form binder concentration in the pressed material. The binder can, for example, be supplied in granulate form.

In another variant, the feed device (5) can be designed as a blowing or spraying device. This blows a dry or liquid binding agent across or at an angle into a passing stream of small plant parts. The binder can be in any suitable consistency and form. For example, a dry binder can be granulated or powdered. The binder can also be liquid.

The hardening or cooling channel (12) connects to the heating device (8) and is used for cooling or residual hardening of the heated strand (2). In addition, drying or evaporation of the strand (2) can take place here. The curing or cooling channel (12) can have the above-described movable channel wall with adjusting device (24).

In the hardening or cooling channel (12), the strand can harden in the desired manner and with the required temperature level brought about by the vapor deposition and the high-frequency heating and then be cooled. If necessary, heat can be supplied to the strand. The specified temperature level in the strand can be maintained for the duration of the hardening, despite possibly fluctuating ambient conditions. The supply of heat from the wall of the press channel can, for example, prevent the strand from cooling down prematurely.

The separating device (13) is arranged at the end of the press channel (7) and separates extruded products (14) from the supplied strand (12). The separating device (13) can be designed, for example, as a saw, in particular a chop saw, and can separate extruded products (14) in the form of blocks from the strand (12) by means of cross-sections.

Figure 1 shows such training.

In the variant of Figure 2 the separating device (13) is designed as a compartment separating device which makes several successive separating cuts with different, in particular intersecting, orientations on the strand (2).

The strand (2) can have different cross-sectional shapes. Figures 3 to 5 show different variants. In the simplest and not individually illustrated embodiment, the rod-shaped strand (2) has a round, in particular circular, or prismatic cross-section. For block production, for example, it has a rectangular cross-section with chamfered corners or longitudinal edges. The strand (2) can have a solid or hollow cross-section.

Figures 3 to 5 illustrate a variant in which the strand (2) has a significantly larger cross section than the final extruded product (14). From the rod-shaped strand (2), for example, according to Figure 3 four strips, each with a smaller cross-section, can be produced by means of an upright and a horizontal separation cut. The inner phase of the four strips can be formed through a central pin hole with a diamond-shaped cross-section at the intersection of the intersection lines shown in dashed lines.

Figure 4 shows a variant of a rod-shaped strand (2), which has two circular strand halves, which are connected to one another by a transverse web. The strand halves can be separated by an upright separating cut and then the extruded products (14) can be separated in the form of blocks or disks by means of cross-sections. The same embodiment of a strand (2) is also shown in FIG Figure 6 in conjunction with a adapted high-frequency heating (10) is shown.

Figure 5 shows a further variant of a rod-shaped strand (2) with a plurality of strand areas which have a curved outer contour at least in some areas. Using upright and lying separating cuts and subsequent transverse separating cuts, appropriately contoured disks with circular arcs and a subsequent truncated cone can be cut off.

As Figure 1 shows, the extrusion device (4) has a control (29) and a measuring device (30) for the strand (2) and / or the extruded products (14). The control (29) can be arranged on the extruder (6) or at another suitable location. It is connected to the single or multiple existing measuring device (30) as well as to the actuating devices (24), the supply device (26) and the actuators of the steaming device (9). The one or more measuring devices (30) can be arranged at one or more points along the strand (2) and / or also in the area where the separated extruded products (14) are transported away. Such measuring devices (30) can, for example, record the density, weight, moisture, strength, surface quality or other relevant physical parameters of the strand (2) and / or the extruded products (14). The measurement results can be reported to the control (29). The control (29) can then control or regulate the extrusion device (4) and its components including the feeding device (5) and the separating device (13) accordingly. It can also act accordingly on the extrusion process, in particular the drive (16).

Modifications of the embodiments shown and described are possible in various ways. In particular, the features of the various exemplary embodiments and the aforementioned variants can be combined with one another as desired, in particular also interchanged.

REFERENCE LIST

1

Extrusion line

2

strand

3

Processing of pressed material

4th

Extrusion device

5

Feeding device for binding agents

6th

Extrusion press

7th

Press channel

8th

Heating device

9

Steaming device

10

High frequency heating

11

Evaporation device

12th

Curing or cooling channel

13th

Cutting device, saw

14th

Extruded product, log

15th

Small parts feed

16

Drive, cylinder

17th

Press organ, press ram

18th

Pressing direction

19th

Machine frame

20th

Filling station

21st

Form channel, recipient

22nd

Canal wall fixed

23

Movable duct wall

24

Adjusting device

25th

Field producer

26th

Utility

27

insulation

28

Adjustment means

29

steering

30th

Measuring device

Claims (15)

1. Extrusion device for manufacturing extruded products (14), in particular blocks, from an extrusion material, consisting of small parts of vegetable matter, in particular small parts of wood, provided with a thermocuring binder, the extrusion device (4) producing a rod-shaped cured strand (2) and having an extruder (6) with an extrusion channel (7) adjoining in the direction of extrusion (18) and a heating device (8) acting on the strand (2) there, the heating device (8) having a steam-curing device (9), characterized in that the heating device likewise has a high-frequency heating unit (10).
2. Extrusion device according to Claim 1, characterized in that the steam-curing device (9) and the high-frequency heating unit (10) together, and in coordination with one another, introduce into the strand (2) the heat required for curing the strand.
3. Extrusion device according to Claim 1 or 2, characterized in that the feeding device (5) feeds to the small parts of vegetable matter an organic binder that gives off water during curing, in particular a Maillard binder.
4. Extrusion device according to one of the preceding claims, characterized in that the steam-curing device (9) is controlled in dependence on the energy input of the high-frequency heating unit (10) and on the moisture available in the strand (2), the amount of steam and the condensation enthalpy thereof being correspondingly adapted.
5. Extrusion device according to one of the preceding claims, characterized in that the steam-curing device (9) has an inner steam-curing unit with a steam feed from an inner pin and an outer steam-curing unit with a steam feed from an outer channel sleeve.
6. Extrusion device according to one of the preceding claims, characterized in that the high-frequency heating unit (10) has one or more field generators (25), arranged on the strand (2), for high-frequency alternating electromagnetic fields.
7. Extrusion device according to one of the preceding claims, characterized in that a wave generator (25) is preceded by a preferably changeable, field-permeable adapting means (28), which contacts the strand (2) and is adapted to the outer strand contour.
8. Extrusion device according to one of the preceding claims, characterized in that the high-frequency unit (10) has fixed and movable channel walls (22, 23) and an adjusting device (24) for the controlled pressing against the strand (2), and releasing, of the movable channel walls (23).
9. Extrusion device according to one of the preceding claims, characterized in that the adding device (5) is formed as a mixer or as a device for blowing or spraying binder into a stream of small parts.
10. Extrusion device according to one of the preceding claims, characterized in that the high-frequency heating unit (10) is arranged before and/or after the steam-curing device (9) in the direction of extrusion.
11. Extrusion installation for manufacturing extruded products (14), in particular blocks, from small parts of vegetable matter, in particular small parts of wood, provided with a thermocuring binder, the extrusion installation (1) having an extrusion-material preparation unit (3) and an extrusion device (4) for the production of a rod-shaped cured strand (2) according to one of Claims 1 to 10.
12. Method for manufacturing extruded products (14), in particular blocks, from an extrusion material, consisting of small parts of vegetable matter, in particular small parts of wood, provided with a thermocuring binder, by means of an extrusion device (4), the extrusion material being extruded in an extruder (6) to form a rod-shaped strand (2), which is exposed to steam and heated in an extrusion channel (7) adjoining in the direction of extrusion (18) and having a heating device (8), characterized in that the strand is likewise exposed to high-frequency alternating electromagnetic fields and heated.
13. Method according to Claim 12, characterized in that an organic binder, in particular an organic binder that gives off water during curing, in particular a Maillard binder, is fed to the small parts of vegetable matter, in particular small parts of wood.
14. Method according to Claim 12 or 13, characterized in that the heat required for the curing of the strand is introduced into the strand (2) by the steam and the high-frequency alternating electromagnetic fields together and in coordination with one another.
15. Method according to Claim 12, 13 or 14, characterized in that the steam curing of the strand (2) is controlled in dependence on the energy input of the high-frequency heating unit (10) and on the moisture available in the strand (2), the amount of steam and the condensation enthalpy thereof being correspondingly adapted.

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