Patent Description:
In production of polymer-based composite materials, new unused thermosetting two-component binders, based mainly on epoxy resins, or pure thermoplastic mass, especially polyolefins, have been used. There are no known solutions in the field of utilizing waste thermoplastics as binders and recycled glass from photovoltaic panels or other materials as fillers. Currently, composite building and construction materials are produced using hydraulic or pure polymer binders and fillers based on natural aggregates. A disadvantage of this solution is the use of non-renewable resources and the consumption of large amounts of energy for the treatment or production thereof. Another disadvantage of conventionally used composite materials is represented by some of their utility properties that limit their use in outdoor environments, such as frost resistance and resistance to chemical and de-icing agents.

Due to the newness of the composite composition, only general processes for production of similar materials are known, which need to be modified. <CIT> Al discloses an examplary conventional process. For technological reasons, it is necessary to dry the input raw materials of the mixture, and to minimise the energy consumption of the process, it is preferable to prepare a preheated charge, because the downstream technological process operates at higher temperatures (in the order of hundreds of °C) and no energy has to be spent on its reheating for subsequent processing.

The same applies to device for their production that is partially usable from other production processes and needs to be modified. Conventional mixing machines guarantee satisfactory homogenisation but do not offer a comprehensive solution for drying and tempered mixing. The machine design is not dimensioned for use at higher operating temperatures.

The object of the invention is method of production of a composite material for production of building and construction prefabricates, based on waste thermoplastics such as binders and with recycled glass, in particular from photovoltaic panels, with recycled rubber from tyres, from recycled ceramics, mixed building and demolition waste, concrete, ash, and slag, and from other similar waste materials as fillers. The composite contains <NUM> to <NUM> % by weight of waste thermoplastic binder in grain size of <NUM> to <NUM>, <NUM> to <NUM> % by weight of photovoltaic panel glass in grain size of <NUM> to <NUM> and <NUM> to <NUM> % by weight of an iron-based stabilising additive. The composite material is processed at temperatures between <NUM> and <NUM>. The waste glass from photovoltaic panels is composed of ground glass that has been cut off or removed from the photovoltaic panel. The composite material can also be recycled by re-crushing it and adding it back into the composite material production technology.

In general, the composite based on waste thermoplastics made by the method of the invention consists of <NUM> to <NUM> % by weight of waste thermoplastic binder, one-component, or a mixture thereof, in grain size up to <NUM>, and <NUM> to <NUM> % by weight of a filler selected from a group comprising recycled waste and container glass, or recycled glass from photovoltaic panels, sand, gravel, recycled tyre rubber, recycled ceramics, mixed building and demolition waste, concrete, slag, ash, or a mixture thereof, in grain size of up to <NUM>, and <NUM> to <NUM> % by weight of stabilising additive and/or dyes.

In general, the filler content may be less than <NUM> % by weight, for example <NUM>-<NUM> %, preferably <NUM>-<NUM> %. The thermoplastic content can then be higher than <NUM> %, for example <NUM>-<NUM> %. The method disclosed below is the subject of the invention used for production of the composite having such a composition. For illustrative reasons, a device which may be used to perform said method and is not the subject of the invention, is described below. A lower filler content will provide a more flexible composite, while a higher filler content will provide a harder and stiffer composite.

The method of production of the composite consists of first crushing the raw materials into input fractions of binder <NUM> to <NUM> and filler <NUM> to <NUM> after cleaning, if necessary, followed by drying and preheating the raw materials to a temperature of <NUM> to <NUM>, preferably <NUM> to <NUM>, then the individual fractions are mixed and the mixture is homogenised, followed by melting of the mixture in an extruder at a temperatures of <NUM> to <NUM>, wherein the molten mixture is subsequently batched into a press mould, for example in a pressing device, where it is pressed into its final shape and finally cooled.

Washing and/or cleaning in the washer-cleaner can be performed optionally depending on the degree of contamination. This may be followed, as necessary, by penetration in a penetrator, followed by drying and slight preheating of the input raw materials below the melting temperature of the processed thermoplastics, in one dryer or in subdryers for individual components of the composite, and thus moisture is removed from the material. The raw materials are then crushed in a grinder into input fractions of binder up to <NUM> and filler up to <NUM>, followed by batching of the individual fractions with the batcher. The batched fractions are then dried and preheated to a temperature of <NUM> to <NUM>, after which the individual fractions are simultaneously mixed and the mixture is homogenised in a homogeniser, from which the mixture is passed to the extruder, where the mixture is melted at a temperature of <NUM> to <NUM>, wherein the molten mixture is simultaneously or subsequently compressed and batched into a device with a final volume and shape treatment.

The mixture may proceed from the extruder either to the first extrusion device, then it is separated, or to the second casting device to the first moulds, or to the press to the second moulds, or to the first rolling mill, then it is separated and cooled, or it is pulled from the melt in the form of filament in the third filament pulling device and then the product is cooled, or the resulting product after partial cooling is pulled through the second pulling mill to the resulting profile shape.

For the method of production of the composite material, a device for cleaning or washing of the charge material, if necessary, or removal of dust, and subsequent drying in a contact dryer with one mixing rotor for intensive drying of at least one input raw material, preferably followed by a two-rotor counter-rotating tempered homogeniser for mixing a mixture of at least two bulk raw materials, can be used. The contact dryer and the two-rotor tempered homogeniser are provided with a double wall for a flue gas supply for drying and heating the raw material, and at the same time they are provided with a pipe for exhausting the water vapours to the integrated water vapour exhaust. The dryer is preceded by batchers located above the dryer and homogeniser areas and placed over the weight sensors. The first batcher operates the dryer. The hopper is emptied by a mechanical flap. The dried dryer charge is transported to the homogeniser. The second batcher operates the homogeniser, where it weighs the second input raw material. The homogeniser mixes the raw materials with heat exchange between the individual components of the production mixture. The resulting product is emptied by a mechanical flap and rotation of the rotors of the homogeniser. The generation of the water vapour is extracted from the working areas by an integrated water vapour exhaust.

The device for production of composite material can therefore consist successively of at least one washer-cleaner, at least one penetrator, furthermore, at least one dryer with preheating for each of the components of the composite mixture, furthermore, at least one grinder for crushing and grinding the raw materials to the input fraction size, furthermore, at least one raw material fraction batcher provided with a first discharge flap, furthermore, at least one at least one-rotor tempered homogeniser for homogenising the raw materials, followed by at least one-rotor extruder for melting the mixture, and a second batcher for batching the mixture into the device with a final volume and shape treatment.

The composite material production device may be, after the extruder, provided with a first extrusion device with a separating device, or a second casting device into a first mould, or a press for pressing the product into a second pressing mould, or a first rolling mill with a separating device, or a third device for pulling the filament, or a second pulling mill followed by cooling.

Each one of the continuous contact hot-air dryers of the device may be provided with a system for circulating air and/or flue gas to dry and preheat the raw material, inside and/or outside the drying area.

The tempered homogeniser may be provided with rotating blades or a screw.

A melting extruder can consist of at least one working section and at least one working segment, wherein it is usually made up of three sections, namely feeding, compression-melting, and transport-melting and three segments, wherein the extruder consists of a working portion composed of at least one hollow cylindrical stator and at least one cylindrical rotor, composed of at least one segment with at least one constant and/or variable pitch working section, namely a feeding and/or compression and/or melting and/or transport section, wherein the stator is provided with a filling hopper at its input end and is provided with at least one regulated heating element along its length, wherein the stator cavity has continuously the same cross-section, or is graded or continuously tapered, and the rotor is provided at its input end with a regulated drive provided with a bearing and is provided along its length on its outer surface with a helix having one constant or gradually finer pitch, or it is successively provided with multiple helices of finer pitches, wherein at the output end the rotor is mounted loosely, wherein the helix is continuous or is composed of blades and the extruder is provided at the output end with an extrusion head and a second controlled flap for batching the mixture.

The rotor of the extruder preferably consists of several parts provided with a helix of progressively finer pitch.

For example, the extruder is composed of a stator portion and a rotor portion. The stator consists of a working portion composed of a hollow cylinder, which is provided with a filling hopper at its input end and along its length are provided regulated heating segments. The rotor is provided with a regulated drive provided with a bearing at the input end, and along its length it is provided with a helix on the outer surface with one gradually finer pitch, or successively multiple finer pitches. At the output end, the rotor is mounted loosely. The extruder is provided with an extrusion head and a controlled flap at the output end. The placement of the extruder allows tilting of the working axis of the machine.

An advantage of this invention is the maximum possibility of processing otherwise difficult-to-dispose-of waste thermoplastics and other municipal and industrial waste, wherein a firm composite material is produced, which can be used, for example, in the building industry.

The composite made by the method of the invention thus preferably contains <NUM>-<NUM> % of a thermoplastic binder with grain size of up to <NUM>, which may be one-component, i.e., composed of one type of a thermoplastic, or, more preferably, may be multi-component, i.e., composed of a mixture of different thermoplastics. Although multi-component thermoplastics are more difficult to process by default, they are cheaper as a waste raw material because there is no need to sort the plastic waste according to the composition of the individual thermoplastics. The composite material made by the method of the invention preferably contains <NUM>-<NUM> % of the filler with grain size of up to <NUM>, preferably up to <NUM>, which contains glass, e.g., recycled waste and container glass, or recycled glass from photovoltaic panels, automotive glass, etc., sand, gravel, recycled tyre rubber, recycled ceramics, mixed building and demolition waste, concrete, slag, ash, or a mixture thereof. In general, the filler may be any material with the specified grain size and with a firm, stable grain, e.g., sufficiently firm not to disintegrate during pressing, in particular preferably sand, aggregate, glass, building recyclates, bottom ash or slag. Thus, the filler may be, for example, only one of the materials mentioned, or a combination of some or all of them, in any ratio by weight. Materials that have no other suitable use, such as automotive glass or glass from solar panels, which cannot be recycled as efficiently as, for example, container glass, are particularly preferably used. Furthermore, the composite may comprise optional components such as stabilising additives, e.g., additives containing ferric oxide to increase UV resistance, dyes, flame retardants, etc. Furthermore, the composite may contain, for example, up to <NUM> % impurities, such as small pieces of metal and other non-meltable impurities, preferably not exceeding <NUM>-<NUM>. The binder may comprise, for example, polyolefins, polypropylene, polyethylene, PET, etc. A fundamental advantage of the composite made by the method of the invention is the possibility of using waste raw materials which are difficult to recycle or completely non-recyclable in the state of the art. The resulting composite is firm and durable enough to be used, for example, as a building material.

A binder content of a certain grain size means that the composite was produced from a binder of that grain size, i.e., the grain size of the binder before melting is given. The filler retains the grain size of the original raw material even in the resulting composite.

Preferably, the composite made by the method of the invention, regardless of its particular composition, does not comprise any adhesive or other non-thermoplastic binder.

Preferably at least half of the weight of the filler is composed of a filler with grain size of at least <NUM>. In other words, the so-called dust component with grain size of less than <NUM> forms smaller part of the filler (by weight) than the component with larger grain size. The grain size is normally measured as the largest dimension of the grains. Such limited proportion of the dust component results in a firmer resulting composite. The grain size of the filler may be, for example, in an interval of <NUM>-<NUM>, preferably for at least half of the weight of the filler.

The object of the invention, which also overcomes to some extent the shortcomings of the solutions known from the state of the art, is furthermore a method of production of a composite having the above-described, and possibly other arbitrary, composition. The method comprises delivering the input raw materials comprising a thermoplastic binder having grain size of up to <NUM>, a filler having grain size of up to <NUM> and optional additional components, wherein it further comprises the following successive steps of: the step of drying the input raw materials in at least one dryer, i.e., the drying may be carried out for all the raw materials (e.g., both the binder and the filler) simultaneously, but it can also be carried out for each component separately, either only separately for the binder and separately for the filler, or, for example, also separately for the individual types of filler, e.g., glass and ash; furthermore, the step of preheating the raw materials below the melting temperature of the binder, e.g., to <NUM>-<NUM>, more preferably <NUM>-<NUM>, more preferably <NUM>-<NUM>; and the step of homogenising the raw materials in a homogeniser, i.e., mixing them thoroughly. The homogeniser preferably maintains the temperature of the raw materials to which they have been preheated. Preferably, the homogenisation of the raw materials is performed until they are delivered to the next step. Subsequently, the raw materials (dried, preheated, and homogenised) are transported to the extruder, wherein in the extruder a part of the homogenised raw materials (in particular the binder) is melted to form a molten mixture, wherein the molten mixture is subsequently degassed and is delivered to the device for final volume and shape treatment of the composite. The extruder preferably performs not only the melting and transport of the mixture, but also its compression, given that the mass per volume (kg·m-<NUM>) of the mixture before melting is typically significantly lower than after it. For example, before the binder is melted, the mass per volume may be about <NUM>·m-<NUM>, while after melting it may be about <NUM>,<NUM>·m-<NUM>.

The degassing is preferably carried out in such a way that the molten mixture is led from the extruder or in a portion of the extruder through an open space, i.e., in particular through a space with access to air from the external environment, so that the vapours from the mixture can exit and be subsequently ventilated. For example, the degassing may be carried out by transport on a belt conveyor or a screw conveyor or the molten mixture may fall freely from the extruder or a portion thereof into another portion, another extruder or conveyor, etc. In principle, it is also possible to use, for example, degassing by means of a valve in the extruder, however, in view of the significantly variable viscosity of the molten mixture, the use of valves may not be very suitable. The device for final volume and shape treatment of the composite may be adapted, for example, for casting the molten mixture, pressing, extruding, etc. Furthermore also for example for cooling, cutting, etc..

The drying step preferably comprises passing the air through the given input raw material, i.e., one of the raw materials, some of the raw materials, or all the input raw materials simultaneously, and removal of this air. For example, the dryer performing this step comprises a fan and air heating device, e.g., a boiler and a radiator. Preferably, the drying further comprises dedusting the air prior to its removal, wherein the dust captured during the dedusting is subsequently returned to the input raw materials. This prevents the discharge of dust particles into the atmosphere, for example by filtering the air carrying moisture away from the input raw materials. It is also possible to perform the dedusting without returning the captured dust back to any of the method steps. This may be preferable, for example, if the content of the dust component of the filler at the input exceeds the preferred <NUM> % by weight of the filler as mentioned above, so it is desirable to remove some of the dust component to improve the properties of the composite. However, it is more preferable to use this return such that the dust does not have to be handled in another manner.

Furthermore, the method may be preceded by a step of grinding the input raw materials to a specified grain size. The input to the method of the invention can therefore be already ground material but also material not ground, wherein then the method comprises a step of grinding or otherwise carried out pulverization of the input materials.

These steps may be preceded, for example, by a step of sorting the input raw materials, e.g., to remove larger pieces of metal, wood, etc., performed, for example, by a magnetic separator or even manually. In particular, this step can protect the grinder or extruder from damage by larger pieces of hard material. A more thorough cleaning of the input materials is also possible, but it is preferably not necessary for the method of the invention, so that neither the moisture of the material nor the cost for the preparation of the material is increased.

The drying step is preferably followed by a step of heat recovery from the removed air. More preferably, this heat is used in the method of the invention, for example to preheat the air for drying, before it is heated by e.g., radiators, to reduce the energy, and thus the cost, demand of the method. However, it is also possible to use the heat from heat recovery elsewhere, e.g., for heating or another industrial process. The heating of the air for drying and preferably also the heating of the homogeniser keeping the raw materials at the preheated temperature after drying upstream of the extruder is preferably carried out by a water-air heat exchanger. Water heating can be performed by a boiler, e.g., solid fuel or natural gas-fired, or it can be water from a heating plant or other industrial process providing waste heat. However, it is also possible to use a radiant heat source, e.g., an electric heating element.

The method of the invention may preferably be a continuous method, wherein all steps take place simultaneously, so that, for example, material is continuously delivered to the dryer for drying and from the dryer the material continuously proceeds to homogenisation, etc. in the other steps. However, it is also possible to carry out the method of the invention as a batch method, where, for example, the next batch of materials to be dried can only be delivered to the dryer after the previous, dried batch has left the dryer.

The melting of the mixture is preferably carried out at a temperature of <NUM>-<NUM>, more preferably <NUM>-<NUM>, more preferably <NUM>-<NUM>, even more preferably <NUM>-<NUM>, and even more preferably <NUM>-<NUM>. The temperature for melting, and thus the temperature of the molten mixture when passing through the extruder, depends in particular on the composition of the binder. It is preferably selected so that none of the thermoplastics forming the binder are destroyed by excessive temperature. More preferably, it is also selected such that all the thermoplastics contained are melted. For example, for a binder composed of a PVC material, a lower temperature in the specified range may be selected, for example <NUM>. For PET, a temperature of around <NUM> may be selected.

The method of production according to the invention preferably further comprises:.

The pressing can take place e.g., in a press with a cooled press mould or in several presses. The cooling of the press mould or calibration chamber can be carried out e.g., using water as a cooling medium. The step comprising extrusion through the extrusion head, calibration, and rolling is particularly preferred for production of the composite made by the method of the invention. The extrusion and calibration will provide any desired shape to the composite material, e.g., a profile with a rectangular cross-section, and the calibration will also create a solidified crust on the surface of the composite due to cooling. The subsequent rolling ensures that the desired shape is maintained and preferably also that the material is further cooled to depth, since cooling during calibration may not be sufficient to completely cool the composite due to the high heat capacity. This can be followed, for example, by separating the composite to the required dimension to produce the final composite product.

Alternatively or additionally, degassing may be followed by at least one of the following steps, performed at least in part by the device for final volume and shape treatment:.

The method can be implemented by a device which comprises at least one dryer for drying and optionally for preheating the input raw materials, at least one batcher for the dried raw materials, e.g., a screw conveyor, a homogeniser for homogenising the raw materials, preferably tempered such that the material is delivered to the extruder slightly preheated, an extruder for melting a portion of the raw materials, a second batcher for the molten mixture, and a device for final volume and shape treatment. For example, there may be a hopper at the input of the device for the delivery of the input raw materials. The device may comprise, for example, one dryer for the binder and another for the filler, both of which pass through a mixing conveyor to the homogeniser, wherein each may have a regulatable feeder at the input, e.g., a calibrated rotary feeder, of the material in question adapted for precise batching. By regulating these feeders, it is then possible to regulate the ratio of the input raw materials. In the case of a common dryer, a separate batcher for the binder and filler may similarly be provided, e.g., a rotary batcher for the binder and a second rotary batcher for the filler, to allow regulation of the ratio of the input raw materials. For example, these batchers are located above the level of the dryers so that the material can fall freely from them into the corresponding dryer after batching.

The device may also comprise a common dryer to which two batchers lead to deliver the appropriate ratio of filler to binder, for example, these may be hoppers with a flap or screw conveyors for batching, preferably adapted to batch the required weight of the individual input raw materials. The extruder may be heated mainly by an electric heating element or by multiple heating elements, in particular because of the need to achieve higher temperatures than are usually achievable with water/air heat exchangers. For this reason, it is particularly preferred to slightly preheat the raw materials in the dryer and/or homogeniser, as the cost of heating with heat exchangers is normally lower than the cost of heating with electricity. The first batcher may be, for example, a conical screw feeder adapted to deliver a precise amount of raw materials to the extruder, preferably depending on the amount of material exiting the extruder as measured by a suitable, e.g., ultrasonic, sensor. The second batcher may be, for example, a batching extruder. The device preferably comprises at least two dryers, one for the filler and one for the binder. Preferably, the material is then transferred from the dryers by the mixing conveyor to the homogeniser. The filler and the binder may require different drying parameters (temperature, air flow, etc.), so it may be more preferred to dry them separately, for example also in the method of the invention described above. The material can then be transported from the dryers via common mixing conveyor, so the device does not need to be equipped with two separate conveyors leading to the homogeniser.

The homogeniser may be implemented, for example, as a bin or container provided with at least one shaft with blades for mixing the raw materials and provided with a batcher for regulated delivery of raw materials to the extruder. When two or more such shafts are used, these shafts are preferably parallel and the paths of their blades may intersect. The batcher of the homogeniser may be, for example, a flap and/or said screw feeder. Thanks to the use of the homogeniser in the device, or the use of homogenisation in the method of the invention, the settling of the input raw materials is prevented and its delivery to the extruder in a precise ratio is ensured. The resulting composite thus has the same properties throughout the entire volume or each piece.

The device is preferred in particular because it allows processing of waste raw materials which are otherwise difficult to use, that is both binder, especially if preferably composed of multiple types of thermoplastics, and filler, and also because all steps of the method of the invention can be performed within a single device. With respect to the method of the invention performed by the device, this device may further comprise means for dedusting the air in the dryer(s), means for heat recovery, etc..

The extruder preferably comprises an extruder input and a rotor comprising at least two sections with helices with different pitches. For example, the first section of the rotor comprises a helix having a first pitch and the second section, located further away from the input to the extruder, comprises a helix having a second pitch smaller than the first pitch. The first pitch can be, for example, <NUM>-<NUM>, the second pitch can be, for example, <NUM>-<NUM> times the first pitch, preferably half. The transition between the pitches can be immediate or gradual. An advantage of such extruder is that the first section ensures uniform charging of the raw materials and the smaller pitch in the second section ensures compression of the extruded material in connection with the increasing bulk density during melting. Preferably, the rotor further comprises a third section located further away from the input to the extruder than the second section and comprising a helix having a third pitch greater than the second pitch, for example the same as the first pitch. The third section, similar to the first, then ensures uniform transport of the molten mixture.

The device may further comprise a second batching extruder which delivers the mixture from the first extruder described above to the device for final volume and shape treatment of the composite, e.g., to an extrusion head, press, casting moulds, etc. Between the two extruders, the molten mixture may be transferred through a free environment wherein degassing occurs.

The extruder preferably comprises a rotor that is at one end mounted loosely. This loosely mounted rotor is preferably the rotor of the first extruder described above, in which the melting takes place and which may comprise said sections with differently pitched helices. Preferably, the loose mounting is at the end of the rotor remote from the input to the extruder. The loose mounting allows for radial deflection of the rotor, for example by at least <NUM>-<NUM>, for example in the case where an impurity or filler grain of a larger size, e.g., larger than <NUM> or larger than <NUM>, is present in the input raw materials.

Preferably, the device for final volume and shape treatment of the composite is provided with a first extrusion device with a separating device, or a second casting device into a first mould, or a press for pressing the mixture into a second pressing mould, or a first rolling mill with a separating device, or a third device for pulling the filament, or a second pulling mill. Most preferably the device comprises an extrusion head, a calibration chamber, and a rolling line, wherein preferably at least some of these components are cooled.

Preferably, the homogenised raw material batcher, i.e., the batcher at the input of the extruder, is a batcher with a regulatable feed rate, wherein it is adapted to regulate the feed rate depending on the amount of mixture passing through the extruder or device for final volume and shape treatment of the composite. For example, a sensor may be present downstream of the extruder or in the extruder or batching extruder for detecting the amount of material passing through the given location. For example, the weight or volume of the material can be sensed. The data from such sensor can be used, especially with use of a regulator or control unit, for feedback regulation of the homogenised raw material batcher such that a desired, preset amount of the composite material is delivered from the extruder to the device for final volume and shape treatment of the composite. Similar feedback may be used, for example, to regulate the delivery rate by the first extruder based on the amount of material being delivered into the batching extruder. Alternatively or additionally, the feedback control can also be used to regulate the drying intensity based on e.g., humidity of the air removed from the dryer, humidity of the input raw materials, etc. The regulated drying parameter can be, for example, air temperature, fan rotation speed, etc..

The degassing section may comprise at least one working chamber, in which the molten mixture passes through an external environment, with a water vapour exhaust.

The batching extruder may comprise at least one working section and at least one working segment, wherein it is usually composed exactly of one section, namely the transport section. The rotor is provided with a regulated drive provided with a bearing at the input end, and along the length thereof it is provided with a helix with one constant pitch and with an extrusion head at the output end.

A summary of the invention is further clarified using exemplary embodiments thereof, which are described with reference to the accompanying drawings, in which:.

There are many exemplary embodiments, and it is not possible to list them exhaustively within the scope of this text.

In a first exemplary embodiment, the composite based on waste thermoplastics contains <NUM> % by weight of a waste thermoplastic one-component binder in grain size of <NUM> and <NUM> % by weight of a filler made from recycled glass from photovoltaic panels of grain size of <NUM>, and <NUM> % by weight of a stabilising additive and dyes.

The method of production of the composite in the first exemplary embodiment is performed by first performing washing in a washer-cleaner <NUM>, then drying and slight preheating of the input raw materials below the melting temperature of the processed raw materials, in two dryers <NUM>, for the individual components of the composite, and thereby removing moisture from the material. This is followed by crushing the raw materials in two grinders <NUM> into the input fractions of the binder, followed by batching of the individual fractions by the batcher <NUM>, which are then dried and preheated to the temperature of <NUM> to <NUM>, whereupon the individual fractions are simultaneously mixed and the mixture is homogenised in a homogeniser <NUM>, from which the mixture proceeds to an extruder <NUM>. This is followed by melting of the mixture at a temperature of <NUM>, wherein the molten mixture is simultaneously compressed and batched into a device for volume and shape treatment, that is, a second casting device <NUM> into first moulds <NUM>, and then cooled.

The device for production of the composite in the first exemplary embodiment consists successively of two washers-cleaners <NUM>, furthermore, two dryers <NUM> with preheating for each of the components of the composite mixture, further at least two grinders <NUM> for crushing and grinding the raw materials to the input fraction size, further at least two batchers <NUM> of fractions of the raw materials provided with a first discharge flap <NUM>. This is followed by one one-rotor tempered homogeniser <NUM> for homogenising the raw materials, followed by one one-rotor extruder <NUM> for melting the mixture, followed by a second batcher <NUM> for batching the mixture into the second casting device <NUM> into the first moulds <NUM>, followed by cooling <NUM>. The extruder <NUM> consists of a working portion composed of one hollow cylindrical stator <NUM> and one cylindrical rotor <NUM>, composed of one segment with one variable pitch working section, namely a simultaneously feeding and compression and melting section. The stator <NUM> is provided with a filling hopper <NUM> at its input end and is provided along its length with one regulated heating element <NUM>, wherein the cavity of the stator <NUM> is continuously tapered. The rotor <NUM> is provided with a regulated drive <NUM> provided with a bearing at the input end, and along its length it is provided with a helix with one gradually finer pitch, wherein the rotor <NUM> is mounted loosely at the output end. The extruder <NUM> is provided with an extrusion head <NUM> at the output end and a second controlled flap <NUM> for batching the mixture.

The composite based on waste thermoplastics in the second exemplary embodiment contains a mixture of <NUM> % by weight of multi-component waste thermoplastic binder in grain size of up to <NUM>, <NUM> % by weight of a half mixed filler from recycled glass from photovoltaic panels and recycled rubber from tyres in grain size of <NUM>, furthermore, <NUM> % by weight of slag also in grain size of <NUM>, <NUM> % by weight of ash, and <NUM> % by weight of a stabilising additive and dyes.

The method of production of the composite in the second exemplary embodiment is performed by first performing cleaning in a washer-cleaner <NUM>, followed by penetration in a penetrator <NUM>, then drying and slight preheating of the input raw materials below the melting temperature of the processed thermoplastics, in subdryers <NUM> for the individual components of the composite and thereby removing the moisture from the material, followed by crushing the raw materials in the grinder <NUM> into input fractions of binder up to <NUM> and filler up to <NUM>. This is followed by batching of the individual fractions with the batcher <NUM>, which are then dried and preheated to a temperature of <NUM>. Subsequently, the individual fractions are mixed, and the mixture is homogenised in the homogeniser <NUM>, from which the mixture proceeds to the extruder <NUM>, where the mixture is melted at a temperature of <NUM>, wherein the molten mixture is simultaneously or subsequently compressed and batched into the device for final volume and shape treatment, that is, the mixture proceeds to a press <NUM> into second moulds <NUM> and subsequently the product is cooled.

The device for production of the composite in the second exemplary embodiment consists successively of multiple washers-cleaners <NUM>, multiple penetrators <NUM>, furthermore, multiple dryers <NUM> with preheating for each of the components of the composite mixture, further multiple grinders <NUM> for crushing and grinding the raw materials to the input fraction size, further of at least multiple batchers <NUM> of fractions of the raw materials provided with the first discharge flap <NUM>, further of one two-rotor tempered homogeniser <NUM> for homogenisation of the raw materials. One one-rotor extruder <NUM> for melting the mixture and the second batcher <NUM> for batching the mixture into the device for final volume and shape treatment follow, and after the extruder <NUM>, it is provided with the press <NUM> for pressing the product <NUM> into the second mould <NUM>, followed by cooling <NUM>.

The extruder <NUM> consists of a working portion composed of one hollow cylindrical stator <NUM> and one rotor <NUM>, composed of one segment with one variable pitch working section, namely a simultaneously feeding and compression and melting section. The stator <NUM> is provided with a filling hopper <NUM> at its input end and with one regulated heating element <NUM> along its length, wherein the cavity of the stator <NUM> is continuously cylindrical. The rotor <NUM> is provided with a regulated drive <NUM> provided with a bearing at its input end and with a helix with one pitch along its length, wherein the rotor <NUM> is mounted loosely at the output end. The extruder <NUM> is at the output end provided with an extrusion head <NUM> and a second controlled flap <NUM> for batching the mixture.

In a third exemplary embodiment, the composite based on waste thermoplastics contains <NUM> % by weight of a waste thermoplastic one-component binder of grain size of up to <NUM> and <NUM> % by weight of a filler made from concrete of grain size of up to <NUM> and <NUM> % by weight of dyes.

The method of production of the composite in the third exemplary embodiment is performed by first performing, according to the degree of contamination, washing and/or cleaning in the washer-cleaner <NUM>, followed by penetration in the penetrator <NUM> as needed, then drying and slight preheating of the input raw materials below the melting temperature of the processed thermoplastics, in one dryer <NUM>, or in subdryers <NUM>, for the individual components of the composite, and thereby removing the moisture from the material. The raw materials are then crushed in the grinder <NUM> into input fractions of binder up to <NUM> and filler up to <NUM>, followed by batching of the individual fractions by the batcher <NUM>, which are then dried and preheated to a temperature of <NUM> to <NUM>, after which the individual fractions are mixed simultaneously. The mixture is homogenised in the homogeniser <NUM>, from which the mixture proceeds to the extruder <NUM> where the mixture is melted at a temperature of <NUM> to <NUM>, wherein the molten mixture is simultaneously or subsequently compressed and batched into the device for final and volume treatment, i.e., into a first extrusion device <NUM>, after which it is separated and cooled.

According to the third exemplary embodiment, the device for production of the composites consists successively of two washers-cleaners <NUM>, one penetrator <NUM>, furthermore, two dryers <NUM> with preheating for each of the components of the composite mixture, further two grinders <NUM> for crushing and grinding the raw materials to the input fraction size, two batchers <NUM> of fractions of the raw materials provided with the first discharge flap <NUM>, further of one one-rotor tempered homogeniser <NUM> for homogenisation of the raw materials. This is followed by one one-rotor extruder <NUM> for melting the mixture, and a second batcher <NUM> for batching the mixture into the device for final volume and shape treatment, that is, into the first extrusion device <NUM> with a separating device <NUM>, and finally followed by the cooling <NUM>.

The extruder <NUM> consists of a working section formed by one hollow cylindrical stator <NUM> and one cylindrical rotor <NUM>, formed by one segment with one variable pitch working section, namely a simultaneously feeding and compression and melting section, wherein the stator <NUM> is provided at its input end with the filling hopper <NUM> and one regulated heating element <NUM> along its length, wherein the cavity of the stator <NUM> has a diameter graded by three grades. The rotor <NUM> is provided with a regulated drive <NUM> provided with a bearing at the input end and it is provided with a helix with three gradually finer pitches along its length, wherein the rotor <NUM> is mounted loosely at the output end. The extruder <NUM> is provided with an extrusion head <NUM> at the output end and a second controlled flap <NUM> for batching the mixture.

Alternatively, the method of production of the composite according to the first exemplary embodiment may be modified such that the crushing takes place prior to washing, wherein the batcher subsequently batches the washed raw materials for drying. The preheating temperature is preferably a maximum of <NUM>. The final treatment is preferably performed by the pressing device instead of casting. The device according to the first exemplary embodiment is then preferably modified accordingly, so that the grinders <NUM> are positioned upstream of the washers-cleaners <NUM>, downstream of which are the batchers. The second batcher <NUM> is preferably a batching extruder <NUM>. The casting device is preferably replaced by the pressing device. The device in this modified first exemplary embodiment preferably comprises a degassing zone <NUM>. The batching extruder <NUM> preferably comprises a working portion comprising one hollow cylindrical stator <NUM> and one cylindrical rotor <NUM>, which comprises one segment with one working section with a constant helix pitch. The stator <NUM> is provided with the filling hopper <NUM> at its input end and with one regulated heating element <NUM> along its length, wherein the cavity of the stator <NUM> is constant. The rotor <NUM> is provided with a regulated drive <NUM> provided with a bearing at the input end, and it is provided with a helix with one constant pitch along its length, wherein the rotor <NUM> is mounted loosely at the output end. The batching extruder <NUM> is provided with the extrusion head <NUM> at the output end.

The composite according to the second exemplary embodiment above is preferably modified such that the rubber is replaced by foundry sand of grain size of <NUM>. In the method of production in the second exemplary embodiment, the crushing preferably takes place prior to cleaning and penetration is preferably not a part of the method. The preheating temperature is preferably <NUM>, the melting temperature <NUM>. The device according to the modified second exemplary embodiment then preferably does not contain the penetrator <NUM>, wherein the grinders <NUM> are located upstream of the washers-cleaners <NUM>.

The method according to the third exemplary embodiment is preferably also modified, wherein the crushing also takes place preferably before the optional washing and subsequent batching by the batchers. The preheating temperature is preferably a maximum of <NUM>. The device according to the third exemplary embodiment then preferably comprises two grinders <NUM> upstream of the washers-cleaners <NUM>, wherein the batchers are preferably upstream of the dryers <NUM>.

In another embodiment, the composite made by the method of the invention is a low-fill composite, for example containing <NUM>-<NUM> % filler, such as sand. For example, in some embodiments, the composite contains <NUM> % by weight of sand or aggregate and <NUM> % by weight of a thermoplastic binder, such as PVC. In another embodiment, it may contain, for example, <NUM> % by weight of sand and <NUM> % by weight of glass obtained from discarded photovoltaic panels, as well as <NUM> % by weight of a binder composed of a mixture of polyethylene and PET, and, furthermore, <NUM> % by weight of ferric oxide. In another embodiment, it may contain <NUM> % by weight of aggregate, <NUM> % by weight of a dye, and the remainder may be composed of a binder comprising polypropylene and polyethylene. A suitable melting temperature for such a binder would be, for example, <NUM>-<NUM> and the resulting composite would be suitable for rolling, e.g., for production of composite boards. The grain size of the filler in any of the embodiments described above is, for example, in an interval of up to <NUM>, preferably up to <NUM>. For example, the aggregate grain size may be <NUM>-<NUM> and the glass grain size <NUM>-<NUM>. Preferably at least half the weight of the filler has grain size greater than <NUM>. The grain size of the binder in any of the embodiments described above is preferably in an interval of up to <NUM>, for example, said PVC binder may have grain size of less than <NUM>. In all embodiments, the composite may contain, for example, up to <NUM> % of impurities or components other than those mentioned above.

In another embodiment, the composite made by the method of the invention is a high-fill composite, for example with a filler content of <NUM>-<NUM> %. For example, it may contain <NUM> % by weight of a filler composed of equal amounts of auto glass and foundry sand. The remaining <NUM> % may be composed of a binder, for example a mixture of polyolefins, or the composite may contain, for example, <NUM> % by weight of stabilising additives, dyes, or flame retardants such that the binder then makes up <NUM> % by weight. Alternatively, the high-fill composite may contain, for example, <NUM> or <NUM> % filler, such as ash, and <NUM> or <NUM> % binder, such as polypropylene.

In another embodiment, the composite may have a composition at the transition between low-fill and high-fill, for example, it may contain <NUM>-<NUM> % by weight of filler and the remainder is binder and optional other components. Thus, for example, the composite may contain <NUM> % by weight of building waste containing, for example, concrete, ceramics, and aggregate, <NUM> % by weight of ferric oxide, and <NUM> % by weight of a binder that comprises, for example, polyolefins, polypropylene, polyethylene, and PET, or any other thermoplastics, in any, for example, even unspecified, ratios. Alternatively, in another embodiment, the binder may contain a mixture of glass, sand, gravel, recycled tyre rubber, recycled ceramics, mixed building and demolition waste, concrete, slag, ash, etc. The content of such filler, the composition and content of the binder, and any additional components may be, for example, as in any other disclosed embodiment of the composite made by the method of the invention. Alternatively, in any embodiment, the filler may be composed of sand, aggregate, glass, building recyclates, bottom ash, and/or slag. It is also possible to use another material with the desired grain size and with firm grain that will not disintegrate during final volume and shape treatment of the composite. In some embodiments, the composite may be a medium or high-fill composite, i.e., having a filler content of at least <NUM> % by weight, with the remainder composed of binder and optionally the specified optional components.

In general, the filler content of the composite may be in the interval of <NUM>-<NUM> % by weight, preferably <NUM>-<NUM> % by weight, more preferably <NUM>-<NUM> % by weight. The binder content may be <NUM>-<NUM> %, more preferably <NUM>-<NUM> % by weight. The content of the stabilising additives, dyes, etc. may be, for example, <NUM>-<NUM> % by weight. The other features of the composite, such as the composition of the individual input raw materials, may be selected, for example, according to any of the embodiments above.

The method of the invention by which the composite may be produced, for example, according to any of the embodiments above, may comprise delivery of the input raw materials comprising thermoplastic binder having grain size of up to <NUM>, filler having grain size of up to <NUM>, and optional additional components. It may further comprise drying the input raw materials in at least one dryer <NUM>, preheating the raw materials to a temperature below the melting temperature of the binder (in the dryer <NUM> and/or homogeniser <NUM>), and homogenising the raw materials in the homogeniser <NUM>. In another step, the raw materials are transported to the extruder <NUM>, for example, by a screw batcher, wherein in the extruder <NUM> a part of the homogenised raw materials, i.e., particularly the binder, is melted under constant homogenisation to form a molten mixture, wherein the molten mixture is subsequently degassed and is delivered to the device for final volume and shape treatment of the composite. The stabilising additives and/or dye may already be added to some of the input raw materials. Preferably, they are added to the homogeniser <NUM>.

The degassing step may be preferably performed by transporting the molten mixture through a free, open space - the degassing zone <NUM>, i.e., with access to air, such that the water vapours may be released from the mixture. The device is then preferably provided with means for removal of these vapours. For example, in the device for final volume and shape treatment of the composite, a pressing step may take place optionally with cooling, extrusion, casting, rolling, separating, pulling, etc. In a particularly preferred embodiment, the device for final volume and shape treatment of the composite performs the final treatment step comprising extrusion with extrusion head that partially provides the desired cross-sectional shape to the extruded material, calibration in cooled calibration chamber that further adjusts the cross-section of the formed continuous profile to the desired shape and cools at least the surface of the material, and, furthermore, this step comprises rolling, preferably with cooling, to ensure that the resulting composite remains in the shape provided by the extrusion and calibration.

Preferably the method of the invention further comprises dedusting in the dryer <NUM>. The dedusting may be carried out in particular by filtering the air carrying moisture away from the dryer <NUM> by means of an air filter. The captured dust is preferably returned to the input raw materials. Preferably, the method further comprises recovery of heat from the dryer <NUM>, i.e., from the moisture carrying air. This heat is preferably delivered back to the method, especially for preheating the air for drying. The heating of the air for drying can be carried out e.g., by contacting the air with a heat exchanger, preferably a water-air exchanger. For example, water can be heated by a gas boiler, e.g., up to <NUM>, or it can be delivered from outside, e.g., from a heating plant or waste heat source.

The temperature in the dryer <NUM> and/or the homogeniser <NUM>, preferably both, may be, for example, <NUM>-<NUM>, for example <NUM>. The homogenised raw materials then enter the extruder <NUM> preferably preheated. The temperature in the extruder <NUM> may be, for example, <NUM>-<NUM>, in particular <NUM>-<NUM>, depending in particular on the type of binder used, for example, the temperature may be <NUM> for a PVC binder, <NUM> for a binder composed of multiple different thermoplastics, etc. The extruder <NUM> is heated, for example, by an electric heating element, preferably by multiple independently regulated heating elements.

Preferably, in the method of the invention, the amount of raw materials delivered from the homogeniser <NUM> to the extruder <NUM> is regulated by a feedback circuit based on data containing information about the amount of molten mixture passing through the extruder <NUM> or other steps downstream of the extruder <NUM>. Furthermore, preferably, the extrusion rate of the extruder <NUM>, i.e., the amount of material dispensed by the extruder <NUM> per unit time, e.g., the rotational speed of the rotor <NUM> of the extruder <NUM>, may be regulated by the feedback circuit based on data containing information about the amount of molten mixture passing through the next steps downstream of the extruder <NUM>, e.g., the amount delivered to the device for final volume and shape treatment of the composite. For example, the method of the invention may be performed by the device described in the embodiments above or in embodiments to be described below. The device may be modified with respect to the method it performs. Therefore, for example, if the device comprises a press, the method may comprise a pressing step, if the device comprises a casting mould, the method may comprise casting the resulting composite, if the device comprises a grinder of the input material, the method may comprise grinding, e.g., of a binder, etc..

The device for production of the composite by the method of the invention according to the embodiment shown in <FIG>, comprises optional components for the pre-preparation of the input raw materials (see <FIG> and <FIG>), namely a binder input conveyor <NUM>, e.g., a chain conveyor, and a magnetic binder separator <NUM> with grinders <NUM>, a binder silo <NUM>, and a binder conveyor <NUM>. Furthermore, the components for the pre-preparation comprise a filler hopper <NUM> visible in <FIG> and <FIG>. Furthermore, the device comprises two belt dryers <NUM>, namely one binder dryer <NUM>' provided with a binder batcher <NUM> and one filler dryer <NUM>" (see <FIG> and <FIG>). The dryers <NUM>', <NUM>"_ are connected to a hot water supply and comprise a fan to create a stream of air heated by the water-air heat exchanger. Furthermore, the device comprises a homogeniser <NUM>, to which the raw materials from the dryers <NUM>', <NUM>" are delivered, e.g., by screw conveyors. In the embodiment shown, a first batcher <NUM>' is used for mixing and a first batcher <NUM>" for elevating the raw materials for subsequent delivery to the homogeniser <NUM>. The homogeniser <NUM> contains means for mixing the input raw materials, for example rotary blades or a screw. The homogeniser <NUM> is preferably also connected to the hot water supply. Downstream of the homogeniser <NUM>, in the direction of passage of the raw materials through the device, a conical screw feeder is located, through which the mixture of the input raw materials is batched into the extruder <NUM>, or a pair of extruders <NUM> or the extruder <NUM> with a pair of rotors <NUM>.

The extruder <NUM> comprises a rotor <NUM> and a stator <NUM>, wherein the stator <NUM> defines an input to the extruder <NUM>, a space for mounting the rotor <NUM>, a space for passing the mixture around the rotor <NUM>, and an exit from the extruder <NUM>. The rotor <NUM> is preferably mounted loosely at its rear end and comprises three helical sections. The first section and the third section have the same first helix pitch and are used to feed the material. The middle, second section has a smaller second helix pitch than the first pitch and is used to compress the material during melting. The heating of the space for passage of the mixture around the rotor <NUM> is preferably performed by an electric heating element located along the rotor <NUM> or multiple such elements. Downstream of the extruder <NUM>, the batching extruder <NUM> is located, representing here a second batching extruder <NUM>, wherein between these extruders the molten mixture passes through the degassing zone <NUM> with an open environment for its degassing. The batching extruder <NUM> may comprise a rotor <NUM> with a helix (screw), a belt conveyor, etc., and is used in particular to transport degassed material to the device for the final volume and shape treatment (see <FIG> and <FIG>) which, in the embodiment shown, comprises an extrusion head, a calibration chamber <NUM>, a rolling line with a cooling zone <NUM>, and a cutting device, in the shown embodiment, a saw <NUM>. The extrusion head, the calibration chamber <NUM> and/or the rolling line may be cooled, e.g., by water, preferably they are all cooled. For example, the cutting device may cut with compressed air and cutting tools, water cutting, etc., may also be used. For example, a unit <NUM> for palletising the resulting composite product may be provided downstream of device for final volume and shape treatment. In the case of using multiple extruders <NUM> or extruder <NUM> with multiple rotors <NUM>, the device for final volume and shape treatment may comprise each of the above components from the degassing zone <NUM> to the unit <NUM> for palletising twice.

Preferably, the device further comprises a unit for recovering heat from the air removed from the dryers <NUM>, and optionally also heat removed from the resulting composite material during cooling. Furthermore, the dryers <NUM> preferably comprise a dust filter or filters and means for returning the captured dust, from the air removed from the dryers <NUM> back to the method, e.g., to the material in the dryers <NUM>, or to the homogeniser <NUM>, etc. In some embodiments, the device may comprise a plurality of different devices for the final volume and shape treatment. For example, the device of <FIG> may alternatively comprise a press through which one portion of the produced composite material passes and an extrusion head followed by the calibration chamber <NUM> and the rolling line. For example, in a device with multiple extruders <NUM>, each extruder <NUM> (or batching extruder <NUM>) may dispense material for a different final volume and shape treatment.

In alternative embodiments, the device for final volume and shape treatment may comprise the first extrusion device <NUM>, the second casting device <NUM>, the press <NUM>, the first rolling mill <NUM>, the third filament pulling device <NUM>, second pulling mill <NUM>, or a combination thereof. The batching extruder <NUM>, or other device providing delivery of the molten degassed mixture, may be adapted for batching a predetermined amount into the device for final volume and shape treatment, for example, delivery into a weighted casting or press mould. For example, it can be stopped after the required amount has been delivered or it can contain a closing flap. In another alternative embodiment, the components of the device may not be the disclosed components for the pre-preparation of the input raw materials or their bins. The device may, for example, start with hoppers for filler and binder at the beginning of the corresponding dryers <NUM> or bins for raw materials, where the sorting of the raw materials, their grinding, etc. may take place in other devices. In addition to multiple parallel dryers <NUM> for different input raw materials, the device may alternatively or additionally comprise multiple dryers <NUM> located in series.

Preferably, the device comprises a regulator or control unit or multiple regulators or control units, wherein it comprises suitable sensors for delivering data to such a control unit. For example, sensors can monitor the amount of material passing through a certain portion of the device, and based on this data, the control unit regulates the delivery of the material in another portion of the device. Thus, for example, if less material than required is delivered at the output from the batching extruder <NUM>, the control unit may adjust the feed rate of the material from the homogeniser <NUM> to the extruder <NUM>, or the delivery rate of the material to the dryers <NUM> and from the dryers <NUM> to the homogeniser <NUM>.

Preferably, the input of the raw materials into the dryers <NUM> is provided by regulatable rotary feeders that provide precise batching of the input raw materials and thus their ratio and thus the properties of the resulting composite. The screw conveyor (the first batcher <NUM>) is preferably used for the transport from the dryers <NUM> to the homogeniser <NUM>, which does not need to be regulatable and the raw materials can be freely delivered from it, e.g., by free-falling, to the homogeniser <NUM>. At the output of the homogeniser <NUM> there is preferably a closing flap downstream of which there is said conical screw feeder, preferably regulated by feedback according to the amount of material delivered by the extruder <NUM>, wherein this feeder takes the desired amount of the homogenised raw materials and delivers it to the extruder <NUM>.

In any embodiment, the homogeniser <NUM> may comprise, for example, one rotor, e.g., a shaft with blades, or multiple such rotors. The blades nay be preferably adjustable, for example with respect to the composition of the input raw materials. In alternative embodiments, the device may comprise a single dryer <NUM> for all input raw materials or even more than two dryers <NUM>, etc. In some embodiments, the extruder <NUM> may also comprise a plurality of rotors <NUM>, for example arranged in parallel side by side. Alternatively, the extruder <NUM> may comprise a rotor <NUM> with a single section or two sections, or it may be composed of multiple extruders or multiple rotors <NUM> that may have different helix pitches to provide said compression.

The composite made by the method of the invention may be used in a number of fields, in processing of various waste into practically usable products. In the building industry as various blocks, floors of workshops, and various plants, for pavements, road surfaces, walls, fences, roofing, target and partition walls of shooting ranges, noise barriers, barriers against drifts, protective walls and cells against infantry weapons, as a construction material for building and mechanical purposes, in the construction of halls and steel structures, in the production of tanks, for urban furniture, as part of the armouring of military equipment.

Claim 1:
A method of production of a composite based on waste thermoplastics, the method comprising a step of delivering input raw materials comprising <NUM>-<NUM> % by weight of a waste thermoplastic binder of grain size of up to <NUM>, <NUM>-<NUM> % by weight of a filler of grain size of up to <NUM>, and optional additional components, wherein the filler is selected from a group comprising recycled waste and container glass, or recycled glass from photovoltaic panels, sand, gravel, recycled tyre rubber, recycled ceramics, mixed building and demolition waste, concrete, slag, ash, or a mixture thereof, wherein the method further comprises steps of drying the input raw materials in at least one dryer (<NUM>), preheating the raw materials to a temperature below melting temperature of the binder, and homogenising the dried raw materials in a homogeniser (<NUM>), wherein the raw materials are subsequently transported to an extruder (<NUM>), wherein in the extruder (<NUM>), the binder is melted to form a homogenised molten mixture, wherein the molten mixture is subsequently degassed and delivered to a device for final volume and shape treatment of the composite.