System and method for the production of flame-retardant foam

Abstract

System (100) for the production of a flame-retardant foam (1), in particular a polyurethane foam, comprising a flame retardant component supply unit (2) designed to supply at least one flame retardant component (3a, 3b), a foam component supply unit (4) configured to supply at least a first foam component (5a) and a second foam component (5b), a foam component mixing unit (6) designed to ensure conditions under which at least the first foam component (5a) and second foam component (5b) react to form the foam (1), and a component processing unit (7) designed to mix the provided flame-retardant components (3a, 3b) and at least one of the foam components (5a, 5b) into a homogeneous mixture (8a, 8b) and to supply it to the foam component mixing unit (6), characterized by the fact that The component processing unit (7) comprises at least a first working container (9a) and a second working container (9b), each of which is connected to the foam component mixing unit (6) by means of a separate fluidic connection, and wherein the working containers (9a, 9b) are designed independently of each other, so that a separate mixture can be produced in each working container (9a, 9b), wherein the mixture (8a, 8b) of the foam component mixing unit (6) is alternately adjustable to be provided by only one of the working containers (9a, 9b), and wherein at least between the first working container (9a) and the second working container (9b) there is a bidirectional fluidic connection (10) by means of which residues of the mixture can be transferred from the working container (9a, 9b) to the other working container (9a, 9b), which next produces a mixture.

Description

[0001] The invention relates to a system for producing a fire-retardant foam according to the preamble of claim 1 and a corresponding method for producing a fire-retardant foam.

[0002] Foam materials, especially polyurethane-based materials and those used for manufacturing vehicle seat cushions, must meet certain requirements. Their fire properties are of particular importance, with specific guidelines for heat release, total smoke density, and burning height, among other factors. Consequently, any foam intended for use as a vehicle seat cushion component must fulfill these requirements.

[0003] It is known from the prior art that flame-retardant components are added to foams to favorably influence their fire properties. A commonly used flame-retardant component is expandable graphite, which is an intercalation compound of graphite in which mainly acids, usually sulfuric acid, are incorporated between the graphite layers. When exposed to heat, the expandable graphite expands (intumescence) and forms a layer on the material surface, thus slowing down the spread of fire.

[0004] It is further known from WO 90 / 11318 A1 that the size and shape of the expanded graphite particles affect their flame-retardant properties. For example, excessively large particles significantly impair their expansion capacity. Similarly, particles that are too small negatively affect the flame-retardant properties. Expanded graphite in the form of irregular platelets can be particularly advantageously embedded in the foam; however, these platelets are often unintentionally broken up and fragmented during foam production.

[0005] Polyurethane foams are produced via a reaction of polyols and polyisocyanates. It is also known in the art to add the flame retardant component to the polyol component, mix it homogeneously, and then react it with the polyisocyanate component, whereby the flame retardant is incorporated into the foam. The mixing of the polyol component and the flame retardant component typically takes place in a single working vessel or tank equipped with a stirring device. During this mixing process, the flame retardant component, which is present as a solid, is pulverized, depending on the stirring force, the type of stirrer, and the stirring duration. This has a significantly negative impact on the flame-retardant properties of the resulting foam, especially when expanded graphite is used.

[0006] EP3 840 924 B1 shows a device for the production of reactive plastics.

[0007] DE 40 34 046 A1 relates to a manufacturing process for flame-retardant flexible foams.

[0008] EP 4001 335 A1 discloses a method for the production of foam materials.

[0009] The object of the present invention is therefore to provide a system and a method for producing a foam which makes it possible to overcome the aforementioned disadvantages of the prior art.

[0010] This problem is solved by a system for producing a flame-retardant foam, in particular a polyurethane foam, comprising a flame-retardant component supply unit configured to provide at least one flame-retardant component, a foam component supply unit configured to provide at least one first and one second foam component, a foam component mixing unit configured to ensure conditions under which at least the first and second foam components react to form the foam, and a component processing unit configured to mix the supplied flame-retardant components and at least one of the foam components into a homogeneous mixture and to supply it to the foam component mixing unit.wherein the component processing unit comprises at least a first and a second working container, each of which is connected to the foam component mixing unit by means of a separate fluidic connection, wherein the working containers are designed independently of each other so that a separate mixture can be produced in each working container, wherein the mixture of the foam component mixing unit is alternately adjustable to be provided by only one of the working containers at a time, and wherein at least between the first and the second working container there is a bidirectional fluidic connection by means of which residues of the mixture can be transferred from the first working container to the second working container, which then produces a mixture.

[0011] The flame retardant component supply unit according to the invention is configured to supply at least one (first) flame retardant component, wherein the flame retardant component supply unit is configured to supply a determinable or adjustable quantity, based on a mass or volume, of the at least one flame retardant component. The flame retardant component is preferably a solid, in particular a powdered solid. Preferably, the flame retardant component supply unit comprises a feeding device, in particular a chute, for each of the flame retardant components in order to introduce the solids in a dust-free manner.

[0012] According to the invention, the foam component supply unit provides at least a first and a second foam component, wherein the foam components are present separately from one another. The foam component supply unit is suitable for providing specific quantities, based on mass or volume, of each foam component in a determinable or adjustable manner. In this way, the ratio between the foam components, which is crucial for the reaction in the foam component mixing unit, can also be adjusted.

[0013] According to the present invention, the foam component mixing unit is designed to provide reaction conditions such that the foam components can react while retaining the foam, preferably within the mold. This preferably includes mixing the foam components in such a way that the foam-forming reaction can proceed, particularly preferably in a substantially stoichiometric manner. Conditions such as temperature, pressure, and reaction time are also preferably included, although this should not be understood as limiting. It is also conceivable that the foam component mixing unit provides catalysts, crosslinkers, or other additive components that initiate and / or accelerate the reaction. Preferably, the foam component mixing unit comprises a pumping device, in particular a plunger pump, with which the foam components can be injected together under pressure.Preferably, the pumping device is fluidically connected to each of the existing working containers in such a way that a circuit is formed, whereby the mixture from one working container can be returned to the respective working container via the pumping device. This circuit arrangement preferably serves to bring the mixture to a specific, adjustable temperature (reaction temperature).

[0014] The component processing unit according to the invention is designed to homogeneously blend the existing flame-retardant components and at least one foam component, in particular the first foam component, so that a homogeneous mixture is obtained. The component processing unit comprises at least a first and a second working container, wherein the mixing of the components takes place in the existing working containers, such that the mixture is present in the respective working container, and a separate mixture can be produced in each working container. The working containers are designed independently of one another, i.e., each of the working containers is functional on its own, so that the system would also be functional with only one working container. The working containers are designed such that, with variable adjustment, only one of the working containers provides the mixture for the foam component mixing unit at any given time.Consequently, each working container has a separate fluidic connection to the foam component mixing unit, with each fluidic connection being adjustable to open or close. The working containers are interconnected via a bidirectional fluidic connection, which is also adjustable to open or close. The connection is only open when an exchange of the components or mixtures contained therein is required; otherwise, the fluidic connection is closed, particularly when a working container is supplying the foam component mixing unit with the mixture. Preferably, the bidirectional fluidic connection is configured as two unidirectional fluidic connections, each located between two working containers.Each working vessel is further equipped with a stirring device designed to homogeneously blend the flame-retardant components and the foam components. Preferably, the stirring device includes a stirrer capable of achieving particularly gentle mixing, especially by generating only laminar flow. Furthermore, each working vessel preferably includes a temperature control unit with which the components or the mixture within the respective working vessel can be brought to a predetermined temperature. The component processing unit preferably comprises a disposal device designed to collect components and / or mixtures from the working vessels that are not further used in the production of the foam. More preferably, the disposal device is fluidically connected to each of the working vessels, with the fluidic connection being adjustable and lockable.can be opened.

[0015] The system according to the invention makes it possible to divide the flame-retardant components and foam components required for the day among several working containers, instead of using a single container. This allows a separate mixture to be prepared in each working container, which can then be promptly supplied to the foam component mixing unit. In this way, the time the mixture is stirred in the respective working container before further processing is significantly reduced, since the mixtures are preferably prepared staggered, but always in such a way that when one working container is empty, the mixture is ready to be supplied to another. Furthermore, the service life of the flame-retardant components and foam components in the working containers is also reduced, since several smaller mixtures are produced instead of one large mixture.By distributing the required quantities of flame retardant and foam components among several working containers, any excess mixture present to ensure a sufficient quantity can be transferred via the fluidic connection from one working container to another, which will then mix the next batch. This allows the remainder of the first batch to be used for the next batch. Similarly, any leftover mixture (residue), for example, from the previous day or the weekend, can be distributed among all available working containers via the fluidic connection. This ensures that the proportion of the old, degraded mixture is evenly distributed, albeit slightly, across all working containers and thus among all batches to be produced.In summary, the present invention ensures gentler processing of the components through shorter standing and stirring times, as well as reduced material wear, since residues of mixtures can be transferred from one working container to another. Furthermore, the failure of a working container due to a defect does not lead to a system shutdown.

[0016] The flame retardant component can be introduced into at least the first and second working containers via the flame retardant component supply unit, and the first foam component can be introduced into the foam component supply unit. In this way, the total quantities of flame retardant components and foam components required to produce the mixture can be distributed among the available working containers.

[0017] The at least one flame-retardant component is expandable graphite. Preferably, the expandable graphite is used in the form of platelets, which ensure particularly good fire protection. Preferably, the first foam component is a polyol and the second foam component is a polyisocyanate. When the polyol and the polyisocyanate react in the foam component mixing unit, a polyurethane foam is preferably obtained. Expandable graphite is a particularly advantageous flame retardant, and the gentle processing of the flame-retardant component, which is ensured by the present system, preserves the expandable graphite platelets, minimizing their comminution and thus advantageously maintaining their flame-retardant effect.

[0018] It is conceivable that the flame retardant component dispensing unit is configured to provide at least one additional flame retardant component. This additional flame retardant component can be dispensed to the component processing unit independently of the first flame retardant component, and can be dispensed into any of the working containers. The additional flame retardant component is preferably melamine, although any known suitable flame retardant component can be used.

[0019] The mixture can be transferred from the first working container to the second working container and vice versa via the bidirectional fluidic connection. Preferably, the mixture can only be transferred to the working container that supplies the foam component mixing unit. Via the bidirectional fluidic connection, which exists between all the working containers, any remaining mixture can be transferred from one working container to another and / or residues in one working container can be evenly distributed among all the working containers.

[0020] According to a preferred embodiment, a control unit is provided, wherein the control unit is configured to control at least the introduction of the flame-retardant components and foam components into the working containers and the transfer of the mixture between the working containers, depending on the fill level of the working containers and / or a predetermined quantity of the mixture to be produced. The corresponding fill level for each working container and / or the quantity of the mixture to be produced can be set or predetermined via the control unit. Furthermore, the control unit preferably controls the supply of the mixture from the working containers to the foam component mixing unit, depending on a stirring duration and / or temperature of the respective mixture. Preferably, the control unit is connected to the units to be controlled, at least via a signal connection.Preferably, the fill level within each working container can be measured by a sensor, the sensor being connected to the control unit via a signal connection. Level sensors are known from the prior art and will not be described further here.

[0021] According to a preferred embodiment, the flame retardant component dispensing unit comprises at least one quantity determination device configured to dispense a predetermined quantity of the flame retardant component partially into the first and second working containers. The quantity determination device allows the total quantity of flame retardant component required to be specified or predetermined, and this total quantity can be divided among the available working containers. The distribution can be uniform or uneven, depending on the quantity of foam to be produced. Preferably, the distribution of the total quantity of flame retardant components among the working containers is controlled by the control unit, depending on the total quantity required and / or the quantity required for the foam to be produced.

[0022] Preferably, the flame retardant component supply unit comprises a quantity determination device for each flame retardant component to be supplied, so that each flame retardant component can be supplied independently of each other in a determinable or adjustable quantity.

[0023] According to a preferred embodiment, the foam component supply unit comprises a first storage container for the first foam component and a second storage container for the second foam component. Preferably, the first foam component can be dispensed from the first storage container into the first and / or the second working container via a fluidic connection. More preferably, the second foam component can be dispensed from the second storage container into the foam component mixing unit via a fluidic connection. The dispensing of the foam components from the storage containers into the working containers or the foam component mixing unit is preferably controlled by the control unit.Preferably, the storage container for at least one foam component, in particular the first foam component, has a fluidic connection with the component processing unit, in particular the first and second working containers. More preferably, the storage container for at least one foam component, in particular the second foam component, has a fluidic connection with the foam component mixing unit. Preferably, the storage containers are designed as IBC containers (Intermediate Bulk Containers).

[0024] It is conceivable that a conditioning unit, as part of the foam component supply unit, is provided between the respective storage container and the component processing unit or the foam component mixing unit. Preferably, the respective foam component can first be fed from the storage container into the corresponding conditioning unit and from there into the component processing unit or the foam component mixing unit. Preferably, the conditioning units are designed to homogenize and temper the respective foam component.

[0025] The problem is also solved by a method for producing a flame-retardant foam, in particular a polyurethane foam, preferably using a system according to one of the preceding claims, comprising the steps: a. Providing a specific quantity of at least one flame retardant component by a flame retardant component provisioning unit and at least one first and second foam component by a foam component provisioning unit; b. Introducing the specified quantity of the flame retardant component partially into a first and a second working container of a component processing unit; c. Introducing the first foam component into the first working container; d. Mixing the flame retardant component and the first foam component in the first working container to obtain a homogeneous first mixture; e. Transferring the first mixture from the first working container into a foam component mixing unit together with the second foam component from the foam component supply unit; f. Obtaining the foam containing the flame-retardant component by reaction of the first with the second foam component in the foam component mixing unit; and g. Repeating steps c. to f. with the portion of the determined quantity of the flame retardant component in the second working vessel to obtain a second mixture, wherein any residue of the first mixture from the first working vessel remaining after step e. is transferred to the second working vessel via the bidirectional fluidic connection between the first and the second working vessel before repeating step c. or f., so that the second mixture contains the residue of the first mixture.

[0026] According to the invention, steps c. to f. are repeated for the flame retardant component in the second container, i.e. the repeated steps are formulated as follows: c'. Introducing the first foam component into the second working container; d'. Mixing the flame retardant component and the first foam component in the second working container to obtain a homogeneous second mixture; e'. Transferring the second mixture from the second working container into a foam component mixing unit together with the second foam component from the foam component supply unit; f'. Preservation of the foam containing the flame-retardant component by reaction of the first with the second foam component in the foam component mixing unit.

[0027] Thus, one foam is obtained from the first mixture and one foam from the second mixture. Preferably, steps c. to f. are repeated for each of the existing working containers into which a portion of the flame retardant component is introduced in step b., so that one foam is produced from each mixture generated in the working containers.

[0028] Any residue remaining in a work container, for example due to an excess of material being used, is completely removed and transferred to the work container where the next (second) mixture is being prepared, so that the remainder of the first mixture becomes part of the second mixture. Thus, no material is wasted.

[0029] According to a preferred embodiment, any residue of the first and / or second mixture, which is contained in the first or second working vessel from a previous execution of the process prior to step a., is distributed equally between the first and second working vessels via the bidirectional fluidic connection between them. This embodiment of the process ensures that any residue of a mixture, e.g., from the previous day or from before the weekend, is still present in one of the working vessels, is distributed evenly between the existing working vessels. For the purposes of the invention, this residue of the mixture is referred to as "old material," which, compared to a fresh mixture, can no longer fully guarantee the advantageous fire-resistant properties.

[0030] All embodiments and features described in connection with the system according to the invention, as well as their advantages, also apply to the method according to the invention and vice versa.

[0031] The foam produced by the inventive method contains at least one flame-retardant component, in particular expandable graphite, with a mass fraction between 1% and 35%. The required fire protection properties can be advantageously achieved through this proportion of expandable graphite.

[0032] Preferably, the fire-retardant foam contains at least one further flame-retardant component, in particular melamine, with a mass fraction between 1% and 35%.

[0033] A vehicle seat cushion component made from the flame-retardant foam according to the invention is provided.

[0034] By using fire-retardant foam to manufacture a vehicle seat cushion component, the required guideline values ​​for fire properties can be advantageously ensured.

[0035] By using the seat cushion component for a vehicle seat, the requirements for fire protection properties, which are particularly stringent in the automotive sector, can be advantageously met. Preferably, the seat cushion component, the backrest cushion component, and the headrest cushion component can be made at least partially from the fire-retardant foam according to the invention.

[0036] Further objectives, advantages and expediencies of the present invention can be found in the following description in conjunction with the drawing. The drawings show: Fig. 1 a schematic representation of a system according to a preferred embodiment; Fig. 2 a sequence of the method according to the invention in a preferred embodiment; Fig. 3 A schematic representation of a vehicle seat according to a preferred embodiment.

[0037] In Fig. Figure 1 schematically illustrates a system 100 for the production of a fire-retardant foam 1, here a polyurethane foam, according to a preferred embodiment of the invention.

[0038] The continuous arrows or lines between the units and facilities generally represent connections, which can be fluidic or solid-transporting. Arrows also indicate a (provisioning) direction. Not all connections are mentioned or explicitly labeled, but they are considered disclosed based on the figures.

[0039] The system 100 comprises a flame retardant component supply unit 2, which is configured to supply a first 3a and a second flame retardant component 3b, a foam component supply unit 4, which is configured to supply at least a first 5a and a second foam component 5b, a foam component mixing unit 6, which is configured to ensure conditions under which the first 5a and second foam component 5b react to form the foam 1, and a component processing unit 7, which is configured to mix the supplied flame retardant components 3a, 3b and the first foam component 5a into a homogeneous mixture 8a, 8b and to supply it to the foam component mixing unit 6.The component processing unit 7 comprises a first 9a and a second working container 9b, which are independently configured, with the mixture 8a, 8b of the foam component mixing unit 6 being supplied alternately by only one of the working containers 9a, 9b at a time. A bidirectional fluidic connection 10 is provided between the first 9a and the second working container 9b, wherein, according to the embodiment shown here, the fluidic connection 10 is configured as two unidirectional fluidic connections which together form the bidirectional fluidic connection 10. The fluidic connections 10 each ensure a transfer from the bottom of one working container to the upper region of the other working container.

[0040] Furthermore, the system 100 includes a control unit 11, which is connected, at least via signaling, to the respective units and / or devices to be controlled or adjusted. The signaling connection is only shown schematically.

[0041] The flame retardant component supply unit 2 is configured to provide a first 3a and a second flame retardant component 3b. For this purpose, the flame retardant component supply unit 2 comprises a first 13a and a second feed device 13b, as well as a first 12a and a second quantity determination device 12b. The first feed device 13a is connected to the first quantity determination device 12a, and the second feed device 13b is connected to the second quantity determination device 12b, such that a preferably powdered solid can be transferred from the feed devices 13a and 13b to the quantity determination devices 12a and 12b. The quantity determination devices 12a and 12b are configured to introduce a predetermined quantity of the flame retardant components 3a and 3b partially and adjustable into the first 9a and second working containers 9b.The feed devices 13a, 13b are designed here as chutes in order to introduce the flame-retardant components 3a, 3b in a dust-free manner.

[0042] A first flame retardant component 3a, here expandable graphite, can be introduced into the first quantity determination unit 12a via the first feeding device 13a, while a second flame retardant component 3b, here melamine, can be introduced into the second quantity determination unit 12b via the second feeding device 13b. The flame retardant component supply unit 2 and the quantity determination units 12a and 12b, respectively, make the flame retardant components 3a and 3b available to the component processing unit 7 and the first 9a and the second working container 9b.

[0043] The foam component supply unit 4 comprises a first storage container 14a and a second storage container 14b, as well as a first conditioning unit 16a and a second conditioning unit 16b. The first storage container 14a is fluidically connected to the first conditioning unit 16a, and the second storage container is fluidically connected to the second conditioning unit 16b. The first conditioning unit 16a is fluidically connected to the first working container 9a and the second working container 9b, and the second conditioning unit 16b is fluidically connected to the foam component mixing unit 6. The conditioning units are designed to homogenize and temperature-control the respective foam components 5a and 5b. The storage containers 14a and 14b are designed as IBC containers.

[0044] The first storage container 14a contains the first foam component 5a, while the second storage container 14b contains the second foam component 5b. The first foam component 5a is a polyol, and the second foam component 5b is a polyisocyanate. The first foam component 5a can be transferred from the first storage container 14a to the first working container 9a and the second working container 9b via a fluidic connection 15a and the first conditioning unit 14a. The second foam component 5b can be transferred from the second storage container 14b to the foam component mixing unit 6 via a fluidic connection 15b and the second conditioning unit 14b. The storage containers 14a and 14b, as well as the conditioning units 16a and 16b, each have a stirring device 17.

[0045] According to the present embodiment, the foam component mixing unit 6 comprises a pumping device 19 and a reaction mixing device 20. The pumping device 19 is configured to pump or convey the mixture 8a, 8b from the first and / or second working container 9a, 9b into the reaction mixing device 20. Furthermore, the pumping device 19 is fluidically connected to the first 9a and the second working container 9b in such a way that a circuit is formed, whereby the mixture 8a, 8b can be transferred from the first working container 8a or from the second working container 9b back into the corresponding working container 9a, 9b via the pumping device 19. This circuit arrangement serves to temper the mixture 8a, 8b or to preheat it to the corresponding reaction temperature.The reaction mixing device 20 is designed to bring together the mixture 8a, 8b and the second foam component under the reaction conditions and thereby initiate the reaction to form foam 1.

[0046] The component processing unit 7 comprises the first 9a and the second working container 9b. Each working container 9a and 9b is equipped with a stirring device 17. In each working container 9a and 9b, a mixture 8a and 8b can be produced from the flame-retardant components 3a and 3b and the first foam component 5a. The first mixture 8a can be produced in the first working container 9a, and the second mixture 8b can be produced in the second working container 9b. The first mixture 8a can be transferred from the first working container 9a to the second working container 9b via the bidirectional fluidic connection 10 or one of the two unidirectional connections 10, and the second mixture 8b can be transferred from the second working container 9b to the first working container 9b via the bidirectional fluidic connection 10 or one of the two unidirectional connections 10.The mixtures 8a, 8b can only be transferred to the working container 9a, 9b, which currently provides the mixture 8a, 8b to the foam component mixing unit 6.

[0047] The Fig. Figure 2 shows a process according to a preferred embodiment of the method 1000 for producing a flame-retardant foam 1, in particular a polyurethane foam, preferably using the system 100 according to Fig. 1. Comprehensive the steps: a. Providing a specific quantity of a first flame retardant component 3a and a second flame retardant component 3b by a flame retardant component provisioning unit 2 and of a first foam component 5a and second foam component 5b by a foam component provisioning unit 4; b. Introducing the specified quantity of the flame retardant components 3a, 3b partially into a first working container 9a and a second working container 9b of a component processing unit 7; c. Place the first foam component 5a into the first working container 9a; d. Mixing the flame-retardant components 3a, 3b and the first foam component 5a in the first working container 9a to obtain a homogeneous first mixture 8a; e. Transferring the first mixture 8a from the first working container 9a into a foam component mixing unit 6 together with the second foam component 5b from the foam component supply unit 4; f. Obtaining the foam 1 containing the flame-retardant components 3a, 3b by reaction of the first foam component 5a with the second foam component 5b in the foam component mixing unit 6; and g. Repeat steps c. to f. with part of the determined quantity of flame retardant components 3a, 3b in the second working container 9b to obtain a second mixture 8b.

[0048] Step g of the described procedure 1000 comprises the following steps: c'. Introducing the first foam component 5a into the second working container 9b; d'. Mixing the flame-retardant components 3a, 3b and the first foam component 5a in the second working container 9b to obtain a homogeneous second mixture 8b; e'. Transferring the second mixture 8b from the second working container 9b into a foam component mixing unit 6 together with the second foam component 5b from the foam component supply unit 4; f'. Preservation of the foam 1 containing the flame-retardant components 3a, 3b by reaction of the first foam component 5a with the second foam component 5b in the foam component mixing unit 6.

[0049] After completing process 1000, at least two foams 1 or foam parts are obtained. It is understood that at least one foam 1 is produced from each of the mixtures 8a, 8b. The specified quantity of the flame retardant components 3a, 3b depends on the quantity of foam 1 to be produced, or rather, on the amount of flame retardant component 3a, 3b required for this purpose. The distribution of the specified quantity of flame retardant components 3a, 3b between the first working container 9a and the second working container 9b depends on how much mixture is needed to produce the corresponding foam 1 at once. The specified quantity of flame retardant components 3a, 3b can also be distributed equally between the working containers 9a, 9b to ensure the shortest possible standing and stirring time for the flame retardant component 3a, in this case, the expandable graphite.

[0050] Before repeating step c., i.e., step c'. (above), it is checked, for example using a sensor, whether any residue of the first mixture 8a remains in the first working container 9a after step e. This check is also possible before repeating step f., i.e., step f'. Such a residue of the first mixture 8a can result from using small excesses to avoid insufficient quantities of mixture for the foam reaction. If a residue of the first mixture 8a is still present in the first working container 9a, it is transferred from the first working container 9a to the second working container 9b via the bidirectional fluidic connection 10 between the first working container 9a and the second working container 9b, so that the second mixture 8b obtained in step d'. contains the residue of the first mixture 8a.This avoids material waste. The illustrated transfer of the remainder of the first mixture 8a from the first 9a to the second working container 9b works analogously to the transfer of a remainder of the second mixture 8b from the second working container 9b to the first working container 9a.

[0051] Furthermore, before executing step a., i.e., before starting process 1000, it is checked whether a residue of the first mixture 8a and / or the second mixture 8b is contained in the first working container 9a or second working container 9b from a previous execution of process 1000. If this is the case, the entire residue of the mixtures 8a, 8b from the working containers 9a, 9b is distributed equally between the first working container 9a and the second working container 9b via the bidirectional fluidic connection 10 between the first working container 9a and the second working container 9b. The quantity of the residue in the working containers 9a, 9b can be determined using sensors in / on the working containers 9a, 9b, such as level sensors, which can be optical or float-type.In this way, old mixtures with deteriorated fire protection properties are distributed among all working containers 9a, 9b and thus all subsequently produced mixtures, so that the remains of the old mixtures do not have to be disposed of.

[0052] The illustrated embodiment of method 1000 relates to a system 100 with two working containers 9a, 9b. It is understood that step g. or steps c'. to f'. are repeated successively for each additional working container.

[0053] In Fig. Figure 3 schematically depicts a vehicle seat 750, which comprises three vehicle seat cushion parts 750 according to the invention. The vehicle seat cushion parts 500 are made of a fire-retardant foam 1 according to the invention, wherein the fire-retardant foam 1 was obtained using the method 1000 according to the invention.

[0054] The vehicle seat upholstery parts 500 are schematically represented as seat cushion upholstery part 500a, backrest upholstery part 500b, and headrest upholstery part 500c. The shape and dimensions are purely illustrative and not intended to be restrictive.

[0055] All features disclosed in the application documents are claimed to be essential to the invention, provided that they are novel individually or in combination compared to the prior art. Reference symbol list 100 System 1000 procedures 500 vehicle seat cushion part 750 vehicle seat 1 foam 2 Flame retardant component supply unit 3a, 3b Flame retardant component 4 foam component supply unit 5a, 5b Foam component 6 Foam component mixing unit 7-component processing unit 8a, 8b Mixture 9a, 9b Work containers 10 fluidic connection 11 Control unit 12a, 12b Quantity determination device 13a, 13b Feed device 14a, 14b Storage containers 15a, 15b fluidic connection 16a, 16b Conditioning unit 17 Stirring device 18 Waste disposal facility 19 Pump system 20 Reaction mixing device

Claims

[1] System (100) for the production of a flame-retardant foam (1), in particular a polyurethane foam, comprising a flame retardant component supply unit (2) designed to supply at least one flame retardant component (3a, 3b), a foam component supply unit (4) configured to supply at least a first foam component (5a) and a second foam component (5b), a foam component mixing unit (6) designed to ensure conditions under which at least the first foam component (5a) and second foam component (5b) react to form the foam (1), and a component processing unit (7) designed to mix the provided flame-retardant components (3a, 3b) and at least one of the foam components (5a, 5b) into a homogeneous mixture (8a, 8b) and to supply it to the foam component mixing unit (6), characterized by , that The component processing unit (7) comprises at least a first working container (9a) and a second working container (9b), each of which is connected to the foam component mixing unit (6) by means of a separate fluidic connection, and wherein the working containers (9a, 9b) are designed independently of each other, so that a separate mixture can be produced in each working container (9a, 9b), wherein the mixture (8a, 8b) of the foam component mixing unit (6) is alternately adjustable to be provided by only one of the working containers (9a, 9b), and wherein at least between the first working container (9a) and the second working container (9b) there is a bidirectional fluidic connection (10) by means of which residues of the mixture can be transferred from the working container (9a, 9b) to the other working container (9a, 9b), which next produces a mixture. [2] System (100) according to claim 1, characterized by, that a control unit (11) is provided, wherein the control unit (11) is designed to control at least the introduction of the flame-retardant components (3a, 3b) and foam components (5a, 5b) into the working containers (9a, 9b) and the transfer of the mixture (8a, 8b) between the working containers (9a, 9b) in an adjustable manner depending on a fill level of the working containers (9a, 9b) and / or a predetermined quantity of mixture (8a, 8b) to be produced. [3] System (100) according to any one of the preceding claims, characterized by , that the flame retardant component supply unit (2) comprises at least one quantity determination device (12a, 12b) which is designed to introduce a predeterminable quantity of the flame retardant component (3a, 3b) adjustable partially into the first (9a) and second working containers (9b). [4] System (100) according to any one of the preceding claims, characterized by, that the foam component supply unit (4) comprises a first storage container (14a) for the first foam component (5a) and a second storage container (14b) for the second foam component (5b), wherein the first foam component (5a) can be adjusted from the first storage container (14a) into the first (9a) and / or the second working container (9b) via a fluidic connection (15a), and wherein the second foam component (5b) can be adjusted from the second storage container (14b) into the foam component mixing unit (6) via a fluidic connection (15b). [5] Method (1000) for producing a flame-retardant foam (1), in particular a polyurethane foam, using a system (100) according to any of the preceding claims, comprising the steps: a. Providing a certain quantity of at least one flame retardant component (3a, 3b) by a flame retardant component provisioning unit (2) and at least one first (5a) and second foam component (5b) by a foam component provisioning unit (4); b. Introducing the specified quantity of the flame retardant component (3a, 3b) partially into a first (9a) and a second working vessel (9b) of a component processing unit (7); c. Place the first foam component (5a) into the first working container (9a); d. Mixing the flame retardant component (3a, 3b) and the first foam component (5a) in the first working container (9a) to obtain a homogeneous first mixture (8a); e. Transferring the first mixture (8a) from the first working container (9a) into a foam component mixing unit (6) together with the second foam component (5b) from the foam component supply unit (4); f. Obtaining the foam (1) containing the flame-retardant component (3a, 3b) by reaction of the first (5a) with the second foam component (5b) in the foam component mixing unit (6); and g. Repeating steps c. to f. with the portion of the determined quantity of the flame retardant component (3a, 3b) in the second working vessel (9b) to obtain a second mixture (8b), wherein a residue of the first mixture (8a) from the first working vessel (9a), which remains after step e., is transferred via the bidirectional fluidic connection (10) between the first (9a) and the second working vessel (9b) to the second working vessel (9b) before repeating step c. or f., so that the second mixture (8b) contains the residue of the first mixture (8a). [6] Method (1000) according to claim 5, characterized by, that any residue of the first (8a) and / or second mixture (8b) contained in the first (9a) or second working vessel (9b) prior to step a. from a previous execution of the process (1000) is distributed in equal parts between the first (9a) and the second working vessel (9b) via the bidirectional fluidic connection (10) between the first (9a) and the second working vessel (9b).

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