WO2026027347A1

WO2026027347A1 - Impregnation system and method for applying a liquid impregnation agent on a wooden workpiece

Info

Publication number: WO2026027347A1
Application number: PCT/EP2025/071032
Authority: WO
Inventors: Matthias Gros; Stefan Schiele
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-07-29
Filing date: 2025-07-22
Publication date: 2026-02-05
Anticipated expiration: 2027-01-29

Abstract

The invention refers to an impregnation system (1) for applying a liquid impregnation agent on a wooden workpiece, comprising a vacuum impregnation device (10) for applying the impregnation agent under negative pressure conditions onto the workpiece while the workpiece is transported through the vacuum impregnation device (10) in a transport direction (T), and a flooding device (20) arranged downstream the vacuum impregnation device (10) for flooding the workpiece with the impregnation agent while the workpiece is transported through a working chamber (C) of the flooding device (20) in the transport direction (T).

Description

Impregnation system and method for applying a liquid impregnation agent on a wooden workpiece

The present invention refers to an impregnation system for applying a liquid impregnation agent on a wooden workpiece, the impregnation system comprising a vacuum impregnation device and a flooding device. The invention further refers to a method for applying a liquid impregnation agent on a wooden workpiece in an impregnation system.

Elongated workpieces, especially wooden profiles, can be utilized in a variety of end products, for instance as elements for window frames, for door frames, floor elements and the like. For technical and design reasons, wooden profiles or at least their surfaces usually need to be processed prior to being employed in an application, particularly for chemo-mechanical stability and (therefore) longevity reasons, but also aesthetic reasons. Wood in general and therefore wooden profiles in particular usually comprise a plurality of pores that can complicate the processing of said wooden workpieces. One such possible processing of wooden workpieces is coating and/or impregnating in an impregnation system.

Conventionally, such workpieces are coated, e.g., while being transported in a transport direction. The coated workpieces are then fed to an impregnation device. In the impregnation devices according to the prior art, the workpieces are immersed into a tub holding the impregnation agent. When immersing the workpieces, typically, they are moved in a direction perpendicular to the transport direction, for instance by pivoting the workpiece from a transport device into the tub filled with the impregnation agent. Thereafter, the workpiece is moved back into the transport device for further transporting it in the transport direction. Such process of impregnating the workpieces by immersing them perpendicular to the transport direction, is a batch processing step that deteriorates efficiency of the overall process.

It is therefore an object of the present invention to provide an optimized solution that increases the efficiency of impregnating a wooden workpiece.

The object of the present invention is achieved by an impregnation system for applying a liquid impregnation agent on a wooden workpiece, comprising a vacuum impregnation device for applying the impregnation agent under negative pressure conditions onto the workpiece while the workpiece is transported through the vacuum impregnation device in a transport direction, and a flooding device arranged downstream the vacuum impregnation device for flooding the workpiece with the impregnation agent while the workpiece is transported through a working chamber of the flooding device in the transport direction.

The impregnation system comprises a vacuum impregnation device for applying the impregnation agent under negative pressure conditions onto the workpiece while the workpiece is transported through the vacuum impregnation device in a transport direction. Due to vacuum or negative pressure conditions, less air and/or reduced pressure can be prevalent in the pores which results in more efficient coating and/or impregnation of the workpiece. In other words, vacuum facilitates drawing impregnation agent into the pores. The impregnation system further comprises a flooding device arranged downstream the vacuum impregnation device for flooding the workpiece with the impregnation agent while the workpiece is transported through a working chamber of the flooding device in the transport direction. The downstream flooding device facilitates keeping the surface of the workpiece covered with impregnation agent for a given time period so that impregnation is improved using a continuous impregnation process. Also, a directional and/or orientational change of the workpiece is dispensable, since, according to the invention, the workpiece moves only along the transport direction. Overall, the production of such wooden workpieces, especially wooden profiles, becomes more efficient.

It is conceivable that the impregnation system comprises multiple vacuum impregnation devices, or, alternatively, that the one vacuum impregnation device comprises multiple vacuum modules for applying the impregnation agent under negative pressure conditions onto the workpiece. Analogously, it is conceivable that the impregnation system comprises multiple flooding devices, or, alternatively, that the one flooding device comprises multiple flooding modules for flooding the workpiece with the impregnation agent. The one or the multiple vacuum modules as well as the one or the multiple flooding modules transport the workpiece in the transport direction. Therefore, no directional and/or orientational change of the workpiece is necessary. Furthermore, vacuum modules and/or flooding modules can be spaced apart from each other along the transport direction. However, at least two of the vacuum modules and/or flooding modules can be also arranged inside a common housing. Moreover, - additionally to the vacuum impregnation device, wherein the impregnation agent is applied onto the workpiece - due to the flooding device, the exposure duration of the workpiece to the impregnation agent can be advantageously increased to a predetermined time period, for instance to at least or exactly 18 seconds. A pressure inside the flooding device is preferably equal to or slightly smaller than an ambient pressure in order to prevent or at least reduce loss of impregnation agent from the impregnation system. As for the structure and functionality of the vacuum impregnation device: The vacuum impregnation device may comprise an application chamber through which the workpiece is transported in the transport direction. The workpiece enters the application chamber through an inlet opening and leaves the application chamber through an outlet opening while a vacuum is generated in the application chamber. Inside the application chamber, the impregnation agent is applied onto the workpiece, for instance by means of an application device arranged inside the application chamber. As the application chamber is underpressurized, ambient air is sucked into the application chamber, for instance through the inlet opening and the outlet opening. A mixture of the air sucked in, solid particles like dirt and residuals of the impregnation agent provided by the application device flow through the separation tower with a separation means therein. Residuals of the impregnation agent can be separated by means of the separation means and pumped back into the application chamber, more precisely to the application device. The pumped back impregnation agent can be filtered and reutilized. In addition to the application chamber, the vacuum impregnation device may comprise a deposition tower or separation tower, and a vacuum generator. The vacuum generator may generate the negative pressure conditions necessary inside the application chamber. In other words, the vacuum generator creates suction and therefore a flow/current from an internal volume of the application chamber in the direction of the vacuum generator. The separation tower may be arranged between the vacuum generator and the application chamber.

According to a preferred embodiment of the invention, the impregnation system comprises a blow-off unit arranged downstream the flooding device for blowing off superfluous impregnation agent from the workpiece while the workpiece is transported through the blowoff unit in the transport direction. It is conceivable that the impregnation system comprises multiple blow-off units. Alternatively, the one blow-off unit comprises multiple blow-off modules. Multiple blow-off units or modules can be spaced apart from each or arranged inside a common blow-off housing. The advantage arising from one or multiple blow-off units or modules is that the amount of impregnation agent utilized per workpiece can be reduced. Furthermore, an impregnation thickness on the workpiece can be optimized, depending on the workpiece and its future application requirements. Furthermore, it is also conceivable that the blow-off unit comprises a heating system to facilitate drying of the impregnation agent. Thereby, contamination of units downstream the blow-off unit with impregnation agent may be reduced.

According to a preferred embodiment of the invention, the impregnation system comprises an additional vacuum impregnation device arranged downstream the flooding device for sucking off superfluous impregnation agent from the workpiece or for applying the impregnation agent with a defined coating thickness under negative pressure conditions onto the workpiece while the workpiece is transported through the additional vacuum impregnation device in the transport direction. The additional vacuum vacuum impregnation device may be installed instead of the blow-off unit or additional to the blow-off unit. If the additional vacuum impregnation device serves to suck-off superfluous impregnation agent from the workpiece, preferably no impregnation agent is applied to the workpiece by the additional vacuum impregnation device. In case the additional vacuum impregnation device serves to apply impgregnation agent to the workpiece, it will leave a constant wet film on the surface of the workpiece.

In an advantageous embodiment of the present invention, the flooding device comprises a distribution device for distributing the impregnation agent in the working chamber. Preferably, the impregnation agent will be evenly and/or homogeneously distributed inside the working chamber of the flooding device. As a consequence, the workpiece can be advantageously transported through the surrounding or ambient impregnation agent.

Preferably, the distribution device comprises one or multiple spraying means, for instance one or multiple nozzles, for spraying the impregnation agent into the working chamber. Multiple spraying means can be arranged along a length of the flooding device and spaced apart equally in order to evenly distribute the impregnation agent inside the working chamber. The spraying means can be arranged on one or two lateral inside walls, a top inside wall and/or a bottom inside wall of the working chamber. The spraying means can be attached or connected to any of the inside walls directly. Additionally or alternatively, at least one spraying means can be connected to any of the inside walls indirectly, for instance by means of a connecting means that protrudes advantageously inwards from an inside wall. As a consequence, the impregnation agent can be provided to (more) central volume sections of the working chamber (as opposed to peripheral sections adjacent to the inside walls), thereby optimizing the overall distribution of the impregnation agent. Furthermore, it is also conceivable that the flooding device comprises a cooling system with one or multiple cooling elements. The cooling system can decrease temperature inside the working chamber, thereby avoiding drying of the impregnation agent and facilitating further permeation of the impgregnation agent into the workpiece.

According to a preferred embodiment of the invention, the multiple spraying means are arranged in a plane perpendicular to the transport direction, wherein at least two of the multiple spraying means respectively comprise a different spatial orientation. The entirety of multiple spraying means arranged in a plane perpendicular to the transport direction can be called spray set. The flooding device can comprise multiple spray sets, for example a first spray set being arranged close to the inlet opening and/or a second spray set being arranged in a middle section of the working chamber and/or a third spray set being arranged close to the outlet opening of the flooding device. The spraying means, particularly nozzles, of the first spray set, or at least a first subset of the spraying means of the first spray set, can be directed or oriented towards the middle section of the working chamber. Analogously, the spraying means, particularly nozzles, of the third spray set, or at least a third subset of the spraying means of the third spray set, can also be directed or oriented towards the middle section of the working chamber. In other words, the first subset of spraying means and the third subset of spraying means can be directed, at least partially, towards each other. As a consequence, the impregnation agent can be distributed more uniformly or homogeneously inside the working chamber. A spraying means can have its individual supply pipe in order to individually control an amount sprayed through the spraying means.

According to an advantageous embodiment of the invention, the distribution device is configured for saturating the air inside the working chamber with the impregnation agent or for setting a relative air humidity inside the working chamber at substantially 100% with respect to the impregnation agent. Saturated air or a relative air humidity of substantially 100% with respect to the impregnation agent inside the working chamber can advantageously emulate flooding the workpiece in a tub filled with a liquid impregnation agent and therefore increase an impregnation rate of the workpiece.

In a preferred embodiment of the present invention, the vacuum impregnation device comprises a first transport device for transporting the workpiece in the transport direction and the flooding device comprises a second transport device for transporting the workpiece in the transport direction.

In a preferred embodiment of the present invention, the vacuum impregnation device comprises an application chamber having an inlet opening through which the workpiece can be transported into the application chamber and an outlet opening through which the workpiece can be transported out of the application chamber. Preferably, the inlet opening and the outlet opening are configured so that the workpiece can be transported by the first transportation device of the vacuum impregnation device through the inlet opening and/or the outlet opening. Preferably, the inlet opening and the outlet opening are configured to stay open to the environment of the application chamber when the workpiece is situated in the application chamber. Preferably, the inlet opening and the outlet opening are permanently open to the environment of the application chamber when the workpiece is situated in the application chamber.

In a preferred embodiment of the present invention, the flooding device comprises a working chamber having an inlet opening through which the workpiece can be transported into the working chamber and an outlet opening through which the workpiece can be transported out of the working chamber. Preferably, the inlet opening and the outlet opening are configured so that the workpiece can be transported by the second transportation device of the flooding device through the inlet opening and/or the outlet opening. Preferably, the inlet opening and the outlet opening are configured to stay open to the environment of the working chamber when the workpiece is situated in the working chamber. Preferably, the inlet opening and the outlet opening are permanently open to the environment of the working chamber when the workpiece is situated in the working chamber.

In a preferred embodiment of the present invention, the vacuum impregnation device comprises a first transport device for transporting the workpiece in the transport direction at a first velocity and the flooding device comprises a second transport device for transporting the workpiece in the transport direction at a second velocity which is equal to or greater than the first velocity. Collisions of workpieces can be advantageously avoided with the second velocity being at least equal to the first velocity. Furthermore, in case the second velocity is greater than the first velocity, a distance between a workpiece and a further workpiece directly next to the workpiece can be realized, which enables flooding not only lateral surfaces but also start and end faces of the workpiece and the further workpiece with the impregnation agent.

Preferably, the vacuum impregnation device comprises a stencil that is adapted to the contour of the workpiece so that a gap smaller than 50mm remains between the workpiece and the stencil if the workpiece is transported through the stencil. Preferably, the gap smaller than 30mm, more preferably smaller then 10mm, for instance 5mm. Air flow properties can be set depending on the gap size. As a consequence, application of the impregnation agent can be optimized. For example, the stencil may have a rectangular opening that may be adjusted to the contour of the workpiece by a user of the vacuum impregnation device. Adjustment may be done manually or using a motor.

According to a preferred embodiment of the invention, a cover or enclosure or housing is arranged between the vacuum impregnation device and the flooding device, and a further cover or enclosure or housing is arranged between the flooding device and the blow-off unit. A respective (further) cover or enclosure or housing can form protection against ambient air and solid particles, especially in transition areas between different devices or modules and therefore protect the workpiece chemically and mechanically. A respective cover or enclosure or housing can also enhance air flow between different devices or modules.

In a preferred embodiment of the present invention, the impregnation system comprises one or multiple impregnation agent draining trays and one or multiple impregnation agent return devices, for collecting and returning the impregnation agent into the vacuum impregnation device and/or the flooding device. Each device or module can comprise one or multiple impregnation agent draining tray or, alternatively, the impregnation system comprises one single impregnation agent draining tray that is arranged advantageously below the devices and/or modules. By means of impregnation agent draining trays, especially solid particles can be held back or collected. Analogously, each device or module can comprise one or multiple impregnation agent return devices, or, alternatively, the impregnation system comprises one single impregnation agent return device. By means of the one or the many impregnation agent return devices, impregnation agent can be returned or pumped back into the vacuum impregnation device and/or the flooding device. Therefore, losses of impregnation agent and costs can be reduced.

Preferably, the impregnation system comprises one or multiple filters for filtering the collected impregnation agent prior to returning it to the vacuum impregnation device and/or the flooding device.

According to an advantageous embodiment of the invention, the impregnation system comprises a separate impregnation agent container for providing additional impregnation agent to the system, the separate impregnation agent container being fluidically connected to the vacuum impregnation device and/or the flooding device. By means of a separate impregnation agent container, losses of impregnation agent can be compensated. Additionally or alternatively, the overall quality of used impregnation agent in the impregnation system can be increased by adding unused impregnation agent, especially by decreasing the percentage of particles or dirt inside the impregnation system.

Another object of the present invention is a method for applying a liquid impregnation agent on a wooden workpiece in an impregnation system comprising a vacuum impregnation device, and a flooding device arranged downstream the vacuum impregnation device, wherein the impregnation agent is applied under negative pressure conditions onto the workpiece while the workpiece is transported through the vacuum impregnation device in a transport direction, wherein the workpiece is flooded with the impregnation agent while the workpiece is transported through a working chamber of the flooding device in the transport direction.

The same technical effects and advantages of the inventive impregnation system and its preferred embodiments elucidated above also apply, individually or in combination, to the inventive method.

According to an advantageous embodiment of the invention, the impregnation system further comprises a blow-off unit arranged downstream the flooding device, wherein superfluous impregnation agent is blown off from the workpiece while the workpiece is transported through the blow-off unit in the transport direction.

According to an advantageous embodiment of the invention, the impregnation system comprises an additional vacuum impregnation device arranged downstream the flooding device, wherein superfluous impregnation agent is sucked-off from the workpiece or wherein the impregnation agent is applied with a defined coating thickness under negative pressure conditions onto the workpiece, while the workpiece is transported through the additional vacuum impregnation device in the transport direction.

Further details and advantages of the invention will be explained below with reference to the embodiments shown in the figures.

Figure 1 illustrates schematically a first embodiment of an impregnation system according to the present invention in a top view.

Figure 2 illustrates schematically a second embodiment of an impregnation system according to the present invention in a top view.

Figure 3 illustrates schematically a vacuum impregnation device of the impregnation system according to figure 1 in a schematic illustration.

Figure 4 illustrates schematically a first embodiment of a flooding device of an impregnation system according to the present invention in a side view. Figure 5 illustrates schematically a second embodiment of a flooding device of an impregnation system according to the present invention in a side view.

Figure 6 illustrates schematically a distribution device for distributing the impregnation agent in a working chamber of a flooding device in a front view.

Figure 1 illustrates schematically a first embodiment of an impregnation system 1 according to the present invention in a top view. The impregnation system 1 for applying a liquid impregnation agent on a wooden workpiece, comprises a vacuum impregnation device 10 for applying the impregnation agent under negative pressure conditions onto the workpiece while the workpiece is transported through the vacuum impregnation device 10 in a transport direction T. The impregnation system 1 further comprises a flooding device 20 arranged downstream the vacuum impregnation device 10 for flooding the workpiece with the impregnation agent while the workpiece is transported through a working chamber C of the flooding device 20 in the transport direction T.

The vacuum impregnation device 10 comprises an application chamber 10’ for applying the impregnation agent under negative pressure conditions onto the workpiece. The vacuum impregnation device 10 further comprises a separation tower 10” for purifying the impregnation agent. Furthermore, the vacuum impregnation device 10 comprises a vacuum generator 10”’ for generating the negative pressure conditions inside the application chamber 10’. Fig. 1 further shows an additional separation tower 12 which is optional.

The flooding device 20 comprises multiple, here four, flooding modules 20’. A blow-off unit 30 is arranged downstream the flooding device 20 for blowing off superfluous impregnation agent from the workpiece while the workpiece is transported through the blow-off unit 30 in the transport direction T. The blow-off unit 30 comprises two blowing modules 30’. For the sake of simplicity, no workpiece is shown in Figure 1 or in any other of the following figures.

The vacuum impregnation device 10 comprises a first transport device 11 for transporting the workpiece in the transport direction at a first velocity. Furthermore, the flooding device 20 comprises a second transport device 21 for transporting the workpiece in the transport direction T at a second velocity. The second velocity is equal to or greater than the first velocity which results in avoidance of collisions of workpieces. Moreover, especially in case the second velocity is greater than the first velocity, a gap between two adjacent workpieces can be realized which enables flooding of end faces of the workpieces. Figure 2 illustrates schematically a second embodiment of the impregnation system 1 according to the present invention in a top view. The second embodiment of the impregnation system 1 differs from the first embodiment particularly in the number of flooding modules 20’. The second embodiment comprises seven flooding modules 20’.

Figure 3 illustrates schematically the vacuum impregnation device 10 of the impregnation system 1 according to figure 1 in a side view. The application chamber 10’, the separation tower 10” and the vacuum generator 10’” are fluidically connected to each other. The vacuum generator 10’” creates suction for the generation of the negative pressure conditions necessary inside the application chamber. As a consequence, a flow/current from an internal volume of the application chamber 10’ in the direction of the vacuum generator 10’” is generated. The separation tower 10” is arranged between the vacuum generator 10’” and the application chamber 10’. Inside the application chamber 10’, the impregnation agent is applied onto the workpiece, for instance by means of an application device arranged inside the application chamber 10’. In the application device, the workpiece can be impregnated entirely. As the application chamber 10’” is underpressurized, ambient air is sucked into the application chamber 10’, for instance through an inlet opening and an outlet opening of the application chamber 10’. A mixture of the air sucked in, solid particles like dirt and residuals of the impregnation agent provided by the application device flow through the separation tower 10” with a separation means 10’”” therein. Residuals of the impregnation agent can be separated by means of the separation means 10’”” and trickle, drip and/or flow to a bottom section of the separation tower 10”. The separation means 10’”” can serve as a filtering means for the impregnation agent. However, the impregnation agent can also be filtered in other positions of the vacuum impregnation device 10, for instance at positions P. The filtered impregnation agent collected in the bottom section of the separation tower 10” can be pumped back in to the application chamber 10’ by means of a pump 10””, more precisely to the application device not shown in the figures. In other words, the pumped back impregnation agent can be circulated and - at least to some degree - reutilized. The impregnation system 1 according to figure 1 also comprises a separate impregnation agent container for providing additional impregnation agent to the system 1 , the separate impregnation agent container being fluidically connected to the vacuum impregnation device 10 and/or the flooding device 20. The separate impregnation agent container is not shown in the figures.

Figure 4 illustrates schematically a first embodiment of a flooding device 20 of an impregnation system 1 according to the present invention in a side view. The second transport device 21 comprises rollers 23 for transporting a workpiece W in the transport direction T. The distribution device 25 comprises multiple spraying means S, three of which are visible in figure 4. The distribution device 25 is arranged perpendicular to the transport direction T as seen in the side view of figure 4.

Figure 5 illustrates schematically a second embodiment of a flooding device 20 of an impregnation system 1 according to the present invention in a side view. The second embodiment comprises three distribution devices 25. The first two (with respect to the transport direction T) distribution devices 25 are pivoted in a clockwise direction (with respect to figure 4). The third distribution device 25 is pivoted in a counter-clockwise direction. Pivoting of a distribution device 25 can result advantageously in impregnating of undercuts of the workpiece. The arrangement of multiple distribution devices 25 within a flooding device 20 or a flooding module 20’ further goes along with the advantage of performance increase of the impregnation process. Furthermore, by means of multiple distribution devices 25 a thickness of the impregnation agent on the workpiece W can be increased easily.

Figure 6 illustrates schematically a distribution device 25 for distributing the impregnation agent in the working chamber C of a flooding device 20 in a front view. The distribution device 25 comprises multiple spraying means S for spraying the impregnation agent into the working chamber C. According to the embodiment shown in figure 6, the spraying means S are configured as nozzles. All spraying means S are arranged in a plane perpendicular to the transport direction T, the transport direction T of the workpiece W being directed perpendicular to the drawing plane. The spraying means S are arranged on a piping of the distribution device 25 and protrude inwards of the flooding device 20 such that a workpiece W can even be sprayed directly. The multiple spraying means S or at least a subset of the spraying means S respectively comprise a different spatial orientation. The distribution device 25 is configured for saturating the air inside the working chamber C with the impregnation agent or for setting a relative air humidity inside the working chamber C at substantially 100% with respect to the impregnation agent.

Reference signs:

I Impregnation system

10 Vacuum impregnation device

10’ Application chamber

10” Separation tower

10”’ Vacuum generator

10”” pump

10’”” separation means

12 additional separation tower

I I First transport device

20 Flooding device

20’ Flooding modules

21 Second transport device

23 Roller

25 Distribution device

30 Blow-off unit

30’ Blowing modules

C Working chamber of the flooding device

S Spraying means

T Transport direction

W Workpiece

Claims

Patent claims:

1. Impregnation system (1) for applying a liquid impregnation agent on a wooden workpiece, comprising a vacuum impregnation device (10) for applying the impregnation agent under negative pressure conditions onto the workpiece while the workpiece is transported through the vacuum impregnation device (10) in a transport direction (T), and a flooding device (20) arranged downstream the vacuum impregnation device (10) for flooding the workpiece with the impregnation agent while the workpiece is transported through a working chamber (C) of the flooding device (20) in the transport direction (T).

2. Impregnation system (1) according to claim 1 , characterized by a blow-off unit (30) arranged downstream the flooding device (20) for blowing off superfluous impregnation agent from the workpiece while the workpiece is transported through the blow-off unit (12) in the transport direction (T).

3. Impregnation system (1) according to claim 1 , characterized by an additional vacuum impregnation device arranged downstream the flooding device (20) for sucking off superfluous impregnation agent from the workpiece or for applying the impregnation agent with a defined coating thickness under negative pressure conditions onto the workpiece while the workpiece is transported through the additional vacuum impregnation device in the transport direction (T).

4. Impregnation system (1) according to any of the preceding claims, characterized in that the flooding device (20) comprises a distribution device (25) for distributing the impregnation agent in the working chamber (C).

5. Impregnation system (1) according to any of the preceding claims, characterized in that the distribution device (25) comprises one or multiple spraying means (S), for instance one or multiple nozzles, for spraying the impregnation agent into the working chamber (C).

6. Impregnation system (1) according to claim 5, characterized in that the multiple spraying means (S) are arranged in a plane perpendicular to the transport direction (T), wherein at least two of the multiple spraying means (S) respectively comprise a different spatial orientation.

7. Impregnation system (1) according to any of claims 4 to 6, characterized in that the distribution device is configured for saturating the air inside the working chamber (C) with the impregnation agent or for setting a relative air humidity inside the working chamber (C) at substantially 100% with respect to the impregnation agent.

8. Impregnation system (1) according to any of the preceding claims, characterized in that the vacuum impregnation device (10) comprises a first transport device (11) for transporting the workpiece in the transport direction (T) and the flooding device (20) comprises a second transport device (21 ) for transporting the workpiece in the transport direction (T).

9. Impregnation system (1) according to any of the preceding claims, characterized in that the vacuum impregnation device (10) comprises an application chamber having an inlet opening through which the workpiece can be transported into the application chamber (10’) and an outlet opening through which the workpiece can be transported out of the application chamber (10’).

10. Impregnation system (1) according to claim 9, characterized in that the inlet opening and the outlet opening are permanently open to the environment of the application chamber (10’) when the workpiece is situated in the application chamber (10’).

11 . Impregnation system (1) according to any of the preceding claims, characterized in that the flooding device (20) comprises a working chamber (C) having an inlet opening through which the workpiece can be transported into the working chamber (C) and an outlet opening through which the workpiece can be transported out of the working chamber (C).

12. Impregnation system (1) according to claim 11 , characterized in that the inlet opening and the outlet opening are permanently open to the environment of the working chamber (C) when the workpiece is situated in the working chamber (C).

13. Impregnation system (1) according to any of the preceding claims, characterized in that the vacuum impregnation device (10) comprises a first transport device (11) for transporting the workpiece in the transport direction at a first velocity and the flooding device (20) comprises a second transport device (21) for transporting the workpiece in the transport direction (T) at a second velocity which is equal to or greater than the first velocity.

14. Impregnation system (1) according to any of the preceding claims, characterized in that the vacuum impregnation device (10) comprises a stencil that is adapted to the contour of the workpiece so that a gap smaller than 50mm remains between the workpiece and the stencil if the workpiece is transported through the stencil.

15. Impregnation system (1) according to any of the preceding claims, characterized in that a cover or enclosure or housing is arranged between the vacuum impregnation device (10) and the flooding device (20), and a further cover or enclosure or housing is arranged between the flooding device (20) and the blow-off unit (30).

16. Impregnation system (1) according to any of the preceding claims, characterized by one or multiple impregnation agent draining trays and one or multiple impregnation agent return devices, for collecting and returning the impregnation agent into the vacuum impregnation device (10) and/or the flooding device (20).

17. Impregnation system (1) according to claim 16, characterized by one or multiple filters for filtering the collected impregnation agent prior to returning it to the vacuum impregnation device (10) and/or the flooding device (20).

18. Impregnation system (1) according to any of the preceding claims, characterized by a separate impregnation agent container for providing additional impregnation agent to the system (1), the separate impregnation agent container being fluidically connected to the vacuum impregnation device (10) and/or the flooding device (20).

19. Method for applying a liquid impregnation agent on a wooden workpiece in an impregnation system (1) comprising a vacuum impregnation device (10), and a flooding device (20) arranged downstream the vacuum impregnation device (10), wherein the impregnation agent is applied under negative pressure conditions onto the workpiece while the workpiece is transported through the vacuum impregnation device (10) in a transport direction (T), wherein the workpiece is flooded with the impregnation agent while the workpiece is transported through a working chamber (C) of the flooding device (20) in the transport direction (T).

20. Method according to claim 19, characterized in that the workpiece is transported through the vacuum impregnation device (10) by a first transportation device (11) of the vacuum impregnation device (10) and the workpiece is transported through the working chamber (C) of the flooding device (20) by a second transportation device (21).

21. Method according to any of claims 19 or 20, characterized in that the impregnation system (1) further comprises a blow-off unit (30) arranged downstream the flooding device (20), wherein superfluous impregnation agent is blown off from the workpiece while the workpiece is transported through the blow-off unit (12) in the transport direction (T).