VIBRATING DEVICE FOR AN INSTALLATION FOR PRODUCING A NONWOVEN, FABRIC WEB

Abstract

A vibration device for an arrangement for producing a nonwoven fabric web, wherein the vibration device is configured to be arranged in a transverse direction of the arrangement under a conveyor belt for fibers from which the nonwoven fabric web is produced, wherein the vibration device is configured to cause the conveyor belt and the fibers transported thereon to vibrate, and wherein the vibration device includes a beam whose top side is configured to contact a bottom side of the conveyor belt at least temporarily, wherein the beam is supported or only excited or excitable by the vibration device so that the beam essentially performs or permits no vibrations in a conveying direction of the arrangement.

Claims

1. A vibration device for an arrangement for producing a nonwoven fabric web, wherein the vibration device is configured to be arranged in a transverse direction of the arrangement under a conveyor belt for fibers from which the nonwoven fabric web is produced, wherein the vibration device is configured to cause the conveyor belt and the fibers transported thereon to vibrate, and wherein the vibration device includes a beam whose top side is configured to contact a bottom side of the conveyor belt at least temporarily, wherein the beam is supported or only excited or excitable by the vibration device so that the beam essentially performs or permits no vibrations in a conveying direction of the arrangement.

2. The vibration device according to claim 1, wherein plural unbalance motors are associated with the beam.

3. The vibration device according to claim 2, wherein an even number of the unbalance motors is associated with the beam.

4. The vibration device according to claim 3, wherein two respective unbalance motors of the unbalance motors are driven or drivable with essentially identical frequency but with opposite directions of rotation.

5. The vibration device according to claim 2, wherein two respective unbalance motors of the unbalance motors are arranged essentially symmetrical to a center of the beam with respect to a longitudinal extension of the beam in the transverse direction of the machine.

6. The vibration device according to claim 1, wherein the beam extends over an entire width of the conveyor belt.

7. The vibration device according to claim 1, wherein plural beams are arranged in series and extend over an entire width of the conveyor belt in combination.

8. An arrangement for producing a nonwoven fabric web or a nonwoven fabric web made from fibers made from synthetically produced polymers or industrially produced inorganic fibers, from the group consisting of glass, metal, mineral, ceramic or carbon fibers, the arrangement comprising: a conveyor belt for the fibers from which the nonwoven fabric web is produced; and the vibration device arranged below the conveyor belt according to claim 1.

9. The arrangement according to claim 8, further comprising: a device configured to connect the fibers and arranged downstream of the vibration device.

10. The arrangement according to claim 8, further comprising a forming device configured to lay the fibers onto the conveyor belt wet.

11. A method for producing a non-woven fiber web or a non-woven fiber web made from fibers made from synthetically produced polymers or industrially produced inorganic fibers from the group consisting of glass, metal, mineral, ceramic or carbon fibers using the arrangement according to claim 8, wherein the fibers are at least partially realigned with respect to their position or orientation on the conveyor belt by the vibration device.

12. The method according to claim 11, wherein the beam is caused to vibrate essentially only in one direction orthogonal to a bottom side of the conveyor belt.

13. The method according to claim 12, wherein two unbalance motors connected with the beam are driven at essentially identical frequencies but with opposite directions of rotation.

14. The method according to claim 11, further comprising: after realigning the fibers connecting the fibers with one another by heating a bonding agent so that the bonding agent cures to connect the fibers with one another.

15. The method according to claim 11, further comprising: adjusting a vibration excitation of the beam with respect to amplitude and frequency by adjusting the speed of the unbalance motors or by a position adjustment of unbalance weights connected to the unbalance motors.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The invention is subsequently described with reference to on a schematic not to scale drawing figure, wherein:

[0023] FIG. 1 illustrates a first embodiment of a vibration device according to the invention; and

[0024] FIG. 2 illustrates a second embodiment of a vibration device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 shows a first advantageous embodiment of a vibration device 10 according to the invention. The vibration device 10 includes a beam 12 whose top side includes plural contact elements 14. The contact elements 14 can be made from a material that slides particularly well, e.g. a ceramic material or can be coated with this type of material. When operating the vibration device 10 according to the invention the contact elements 14 contact a bottom side of a conveyor belt 11 at least temporarily in order to transfer vibrations to the conveyor belt 11 and to realign fibers transported on the transport screen at least partially. Thus, the contact elements 14 can be either configured flat or planar on top or they can have a slightly convex curvature in order to facilitate a sliding of the transport screen. Advantageously however, the contact surface is not configured too small so that compressive forces can be distributed from the beam 12 onto the conveyor belt 11 onto a correspondingly large surface so that a wear at the contact elements 14 and/or the transport screen is small. The beam 12 advantageously extends over an entire width of the conveyor belt 11.

[0026] The beam 10 can be supported in beam bearings 16 so that the beam essentially does not allow any movement in the machine direction. The machine direction is defined as the transport direction of the fibers 15 on the conveyor belt 11. The machine direction runs in the plane of the contact elements 14 and orthogonal to the main or longitudinal extension of the beam 12.

[0027] The vibration device 10 according to the invention essentially includes two unbalance motors 18 that are driven during operation of the vibration device 10 essentially at identical speed or frequency but with opposite direction of rotation which is indicated by the arrows 20. The two unbalance motors 18 are essentially arranged symmetrical to a center of the beam 12 with respect to the longitudinal extension of the beam 12 in transversal direction of the machine. Due to this arrangement and operation of the two unbalance motors 18, the vibration excitations of the longitudinal extension of the beam 12 cancel each other, whereas vibration excitations orthogonal thereto, namely in a direction towards the conveyor belt 11 or away from the conveyor belt 11 are augmented. Advantageously unbalance weights in the two unbalance motors 18 are arranged at identical angular orientation relative to each other, this means they reach their highest or lowest position at the same moment. The position of the unbalance weights in the unbalance motors 18 is radially adjustable relative to the rotation axis in an order to adjust a strength of the vibration excitation in a controlled manner. By the same token the frequency or speed of driving the two unbalance motors 18 is adjustable in a controlled manner.

[0028] The vibration device 10 according to the invention facilitates very uniform alignment of the fibers on the conveyor belt 11 over an entire width of the conveyor belt 11. By the same token wear at the contact elements 14 and at the conveyor belt 11 is minimal. Product quality can be precisely controlled. Furthermore, a single vibration device suffices to obtain the desired result. Arranging plural vibration devices in series is not necessary.

[0029] Advantageously the vibration device 10 according to the invention is arranged between a device for applying the fibers to the conveyor belt 11, thus a former or a slanted screen former and a device for connecting the fibers, thus a heating device for curing a bonding agent that connects the fibers.

[0030] FIG. 2 illustrates a second advantageous embodiment of the vibration device 10 according to the invention. This embodiment differs from the embodiment of the vibration device 10 according to FIG. 1 essentially in that two beams 12 with two respective unbalance motors 18 are arranged in a transversal direction of the machine adjacent or behind one another in order to cover a greater width of the conveyor belt 11.

[0031] The two beams 12 can be optionally fixed at each other to form a rigid unit or they can be non-connected with a small distance there between. Advantageously all four unbalance motors 18 are driven essentially at the same frequency wherein the unbalance weights associated with the unbalance motors 18 advantageously reach their highest or lowest position simultaneously. The direction of rotation of two unbalance motors 18 respectively associated with a beam 12 is opposite.

[0032] It is appreciated that more than two beams 12 can be arranged adjacent to or behind one another depending on a length of the beams 12 and a width of the conveyor belt 11. Furthermore, more than 2 unbalance motors 18 can be respectively associated with abeam 12. Advantageously, an even number of unbalance motors 18 is respectively associated with a beam 12.

REFERENCE NUMERALS AND DESIGNATIONS

[0033] 10 vibration device [0034] 11 conveyor belt [0035] 12 beam [0036] 14 contact element [0037] 15 fibers [0038] 16 beam bearing [0039] 18 unbalance motor [0040] 20 direction of rotation arrow