Air laying device

Abstract

The invention relates to an air laying device (1) for producing a fiber mat at least partially from wood pulp fibers and / or paper pulp fibers, the air laying device having an annular distributor (2), the annular distributor having a fiber input section (10) and an annular channel, the annular channel having a discharge piece (3) forming a section of the annular channel, wherein the section is arranged in a settling channel (4) extending downward in the direction of a forming screen (5), and the discharge piece (3) has an opening, through which fibers input from the fiber input section (10) can be discharged from the annular channel into the settling channel (4) and moved to the forming screen in order to form a fiber mat on the forming screen (5).

Description

Technical Field

[0001] The present invention relates to an air-laying device for producing a fiber mat at least partially from wood pulp fibers and / or paper pulp fibers. Background Art

[0002] Devices of this type are known. First, individual fibers or fiber agglomerates are produced and evenly distributed by air flow onto a screen for forming a fiber mat. Air laying devices for laboratory use are operated in batch mode. Individual fiber mats, so-called fiber mat webs, are produced one after another in order to be further investigated in the laboratory with regard to properties, such as mechanical properties. Such devices work very slowly and must be filled manually. Providing individual fibers by dissolving fiber agglomerates is particularly complex.

[0003] Air-laying devices are also known for producing fiber mats in continuous operation. Providing individual fibers by dissolving fiber agglomerates is also particularly complex.

[0004] The known device also has the disadvantage that additives, such as powders, are difficult to mix uniformly with the fibers in the air stream. On the other hand, it is difficult to process fibers having a large number of different fiber lengths. Summary of the invention

[0005] Therefore, the object of the present invention is to provide an air laying device which improves the known devices with respect to the above-mentioned disadvantages.

[0006] The technical problem is solved by an air laying device. An air laying device is proposed for producing a fiber mat at least partially from wood pulp fibers and / or paper pulp fibers, the air laying device having an annular distributor with a fiber input and an annular channel, the annular channel having a discharge piece forming a section of the annular channel, wherein the section is arranged in a settling channel extending downward in the direction of a forming screen, and the discharge piece has an opening through which fibers fed from the fiber input can be discharged from the annular channel into the settling channel and moved to the forming screen in order to form a fiber mat on the forming screen.

[0007] The annular channel of the annular distributor is suitably designed so that the fibers and, if necessary, the fiber agglomerates and additives move in the annular flow generated by the air flow. Part of the fibers and, if present, part of the additives leave the annular channel through the discharge piece and directly enter the settling channel and then arrive on the forming screen to form a fiber mat or fiber mat web. The fiber agglomerates are dissolved into single fibers in the annular flow. Before the fibers leave the annular channel, the fibers are preferably transported in a circle by the annular flow for many times. By rotating for many times, the solubility of the fiber agglomerates is improved on the one hand and a uniform mixing of the solids in the air flow is achieved on the other hand.

[0008] Expediently, wood pulp fibers and / or paper pulp fibers and / or additives are introduced into the air flow via the fiber feed.

[0009] In the region of the fiber feed, air nozzles can be used as spray nozzles in order to generate a negative pressure in the fiber feed.

[0010] In an advantageous embodiment, a plurality of air nozzles are introduced into the annular channel for generating an air flow and for dissolving the fiber clumps, thereby maintaining and driving the annular flow on the one hand, and on the other hand, the air jets of the air nozzles generate pressure pulses on the fiber clumps, so that the fiber clumps are dissolved.

[0011] In a possible further development of the invention, a cleaning nozzle is arranged outside the annular channel for cleaning the opening of the outlet piece. The cleaning nozzle is preferably also designed as an air nozzle.

[0012] The air nozzles and / or the cleaning nozzles can be supplied with a pulsed or oscillating air flow.

[0013] The air nozzle and / or the cleaning nozzle can be fixedly or movably mounted. This makes it possible to adjust the driving effect of the circulating flow on the one hand and the cleaning effect on the other hand. The movably mounted nozzle can be designed for oscillating movement.

[0014] The settling channel may be sealingly abutted against the forming screen or spaced apart from the forming screen.

[0015] The sedimentation channel can be loaded with overpressure.

[0016] The forming screen can be equipped with a suction device, thereby facilitating the fiber laying and producing a more compact fiber mat.

[0017] The opening of the discharge piece can have a width of at most 10 mm.

[0018] The opening can be designed in the form of a slot or in the form of a circle.

[0019] In a possible further development, the annular channel can contain mixing particles for mixing the fibers and for dissolving the fiber agglomerates.

[0020] The air laying device can be suitable for use in a laboratory, and the forming screen can be arranged stationary. The input section can be designed to be closable for this case. This allows the fiber mat to be produced in batch operation.

[0021] The air laying device can also be designed to be suitable for producing a continuous fiber mat, and the forming screen can be moved in the running direction. The forming screen is preferably designed as a circulating belt guided by a plurality of rollers. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further features and advantages of the present invention emerge from the following description of preferred embodiments with reference to the accompanying drawings.

[0023] In the attached picture:

[0024] Figure 1 A simplified schematic diagram shows an embodiment of a device according to the invention having an annular distributor;

[0025] Figure 2 Show according to Figure 1 A simplified schematic side view of an embodiment of the invention; DETAILED DESCRIPTION

[0026] Figure 1In a simplified schematic diagram, an embodiment of a device according to the invention with an annular distributor 2 is shown. The air-laying device 1 is used to at least partially produce a fiber mat consisting of wood pulp fibers and / or paper pulp fibers. The air-laying device has an annular distributor 2, which has an annular channel and a fiber input 10. The annular channel has a section that passes through a discharge piece 3 with an opening, through which the fibers input by the fiber input 10 can flow out of the annular channel into the settling channel 4 and move to the forming screen 5 in order to form a fiber mat on the forming screen 5. The discharge piece 3 has a slit-shaped opening in this example, the size of which is less than 10 mm in width and greater than 10 mm in length. The section with the discharge piece 3 is arranged in the settling channel 4, which extends downward in the direction of the forming screen 5. The annular channel of the annular distributor 2 is suitably designed so that the fibers and, if necessary, fiber agglomerates and additives move in the annular flow generated by the air flow. Part of the fiber and part of the additive (if present) leave the annular channel through the discharge piece and directly enter the settling channel and then arrive on the forming screen to form a fiber mat in batch operation or a fiber mat width in continuous operation. The fiber mass is dissolved into individual single fibers in the annular flow. Before the fiber leaves the annular channel, the fiber is preferably transported in a circle by the annular flow for many times. By rotating many times, the solubility of the fiber mass is improved on the one hand, and the uniform mixing of solids in the air flow is achieved on the other hand. In the region of the fiber input part 10, an air nozzle 6 is used as a jet nozzle to generate a negative pressure in the fiber input part 10, so that wood pulp fibers and / or pulp fibers and / or additives are more easily input into the annular flow of the annular channel. A plurality of air nozzles 6 are introduced into the annular channel along the annular channel of the annular distributor 2 to generate an air flow and dissolve the fiber mass. Thus, the annular flow is maintained and driven on the one hand, and on the other hand, the air jet of the air nozzle 6 applies a pressure pulse to the fiber mass, so that the fiber mass is dissolved into a single fiber. This effect is also assisted in the example by mixed particles 8 for mixing fibers and for dissolving fiber mass. The settling channel 4 is arranged at a small distance from the forming screen 5. The forming screen is equipped with a suction device 11. This assists the laying of the fibers and enables a more compact fiber mat or a more compact fiber mat web to be achieved.

[0027] Figure 2 The simplified schematic diagram shows the Figure 1Side view of an embodiment of the present invention. A cleaning nozzle 7 is shown here for cleaning the discharge member 3, which is loaded with compressed air or air from a fan. In order to improve the cleaning effect, the cleaning nozzle can be arranged in a circular oscillating manner around an imaginary axis perpendicular to the drawing. It is also conceivable that the cleaning nozzle is arranged in an elliptical oscillating manner. In addition, it is possible that the oscillation can be combined with a linear movement. The air laying device 1 can be designed to be suitable for laboratories and the forming screen can be arranged stationary. The air laying device 1 shown is designed to be suitable for continuous production of fiber mats. The forming screen 5 can be moved along the running direction 9 in this case. The forming screen is preferably designed as a circulating belt guided by multiple rollers.

[0028] Corresponding elements in the figures are provided with the same reference numerals. If no other description is given and no contradiction occurs, the functions of these elements in the various figures correspond to each other. Therefore, repeated descriptions are omitted.

[0029] List of Reference Numerals

[0030] 1 Air laying device

[0031] 2 Ring distributor

[0032] 3 discharge parts

[0033] 4 Sedimentation Channel

[0034] 5 Forming screen

[0035] 6 Air Nozzles

[0036] 7. Clean the Nozzle

[0037] 8 mixed particles

[0038] 9 Running direction

[0039] 10 Fiber input unit

[0040] 11Suction device

Claims

1. An air laying device (1) for producing a fiber mat at least partially from wood pulp fibers and / or paper pulp fibers, the air laying device having an annular distributor (2) with a fiber input (10) and an annular channel with an outlet (3) forming a section of the annular channel, wherein: The section is arranged in a sedimentation channel (4) extending downward in the direction of the forming screen (5), and the discharge piece (3) has an opening, through which the fibers input from the fiber input part (10) can be discharged from the annular channel into the sedimentation channel (4) and moved to the forming screen in order to form a fiber mat on the forming screen (5), wherein the opening has a maximum width of 10 mm.

2. The air laying device according to claim 1, characterized in that: Wood pulp fibers and / or paper pulp fibers and / or additives are introduced into the air flow via the fiber input section (10).

3. The air laying device according to claim 1, characterized in that: A plurality of air nozzles (6) open into the annular channel for generating an air flow and for dissolving fiber agglomerates, and / or cleaning nozzles (7) are arranged outside the annular channel for cleaning the opening of the discharge piece (3).

4. The air laying device according to claim 3, characterized in that: The air nozzles (6) and / or the cleaning nozzles (7) are supplied with a pulsed or oscillating air flow.

5. The air laying device according to claim 3, characterized in that: The air nozzle (6) and / or the cleaning nozzle (7) are / is fixedly or movably mounted.

6. The air laying device according to any one of claims 1 to 5, characterized in that: The sedimentation channel (4) is in sealing contact with the forming screen (5) or is spaced apart from the forming screen (5).

7. Air laying device according to any one of the preceding claims 1 to 5, characterized in that The forming screen (5) is equipped with a suction device (11).

8. The air laying device according to any one of claims 1 to 5, characterized in that: The opening is designed to be slot-shaped or circular.

9. The air laying device according to any one of claims 1 to 5, characterized in that: The annular channel contains mixing particles (8) for mixing the fibers and for dissolving fiber agglomerates.

10. The air laying device according to any one of claims 1 to 5, characterized in that: The air laying device (1) is suitable for use in a laboratory, and the forming screen (5) is arranged stationarily.

11. The air laying device according to any one of claims 1 to 5, characterized in that: The air laying device (1) is suitable for producing a continuous fiber mat, and the forming screen is movable in the running direction and forms a continuous loop.

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