Device for Hydrodynamic Intertwining of Fibers in a Fiber Web

Abstract

A device is known in which the bulky felt arriving on the top side of an endless belt for water felting is compacted between a felting drum and the belt and at the same time it is wetted by a first water curtain from a nozzle beam, whose water jets first pass through the endless belt and then the fiber web and finally the felting drum. Now, according to the invention, the unconsolidated felt is held against the bottom of an endless belt by means of induced suction and transported, and it is brought up tangentially to a needle felting drum, arranged beneath the endless belt. In this way, the handover of the fiber web from the endless belt to the needle felting drum is accomplished under the influence of gravity.

Description

FIELD OF THE INVENTION

The present invention relates a device for hydrodynamic intertwining in order to compact the fibers of a web made from one or more of natural and synthetic fibers.

SUMMARY OF THE PRIOR ART

A compacting device is described in European Publication Patent No. EP-A-0 859 076. The compacting device acts to compact bulky felt arriving on an endless belt for a water felting process carried out between a felting drum and two belts, at the same time it is wetted by a first water curtain from a nozzle beam whose water jets pass through the endless belts, the fiber web and the felting drum. A similar process is disclosed by European Patent Publication No. EP-A-0 818 568, in which two felting drums arranged one above the other are used for compacting both sides of the web.

The known device per the '568 Publication addresses the problem of slow compression of a fiber web consisting of loose, unconsolidated fibers that receive upstream wetting in the pressed condition. Even for lighter felts, a danger exists that the loose fibers as they are being compacted will be forced into the felting drum to get caught there and cause problems upon removing the fiber web after the felting process is completed. Also, the device produces a negative slack in the fiber web, which is detrimental to the ultimate strength of the fiber felt.

International Patent Publication No. WO 2004/046444 proposes a process for better loosening the fiber web after the felting process by arranging and orienting the nozzle beam so that the water jets of the bean hit the fiber web in its direction of transport only after the line or region of compression is passed. This process step cleans away the fibers picked up by the endless belt immediately after or during a needle felting step. A second endless belt is passed around the needle felting drum to increase resistance on the drum during felting while transporting the fiber web onward in a tension-free condition. In instances where this second endless belt is not desirable, effective transport of the fiber web may no longer be assured.

SUMMARY OF THE INVENTION

A device for hydrodynamic intertwining in order to compact the fibers of a web made from natural and/or synthetic fibers of any given kind, and preferably free of bonding agents, includes:

• a) a first conveyor belt transporting the fiber web and a subsequent endless belt, which is stretched and deflected between at least two rollers,
• b) a first needle felting drum, coordinated with the endless belt and with at least one first nozzle beam, preferably across the working width of the web,
• c) at least one second nozzle beam having water jets that are directed against a back side of the endless belt and, through the endless belt, against the fiber web and against the first needle felting drum, at least for the wetting of same, while the endless belt is brought up tangentially to the first needle felting drum, above the conveyor belt and the first needle felting drum,
• wherein the fiber web, supported solely on an outer sider of a lower slack portion side of the endless belt, is transferred after a first needle felting by means of the at least one second nozzle beam downward onto the first needle felting drum,
• e) wherein the slack portion of the endless belt, transporting the fiber web, is further coordinated at its slack portion with a suction box under at least a partial vacuum, above the slack portion of the endless belt and the needle felting drum, in order to support the fiber web, and
• f) wherein the endless belt, transporting the fiber web on its slack portion, being coordinated with a conveyor belt upstream from it, which is supported between idler rollers and passes off the fiber web, transports the fiber web on a tight portion of the conveyor belt and hands the fiber web off to the slack portion of the endless belt.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more readily apparent from the Detailed Description of the Invention, which proceeds with reference to the drawings, in which:

FIG. 1 provides a schematic view of a device for hydrodynamic intertwining of fibers in a fiber web that follows principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is further described in detail herein and by way of example, with reference to a preferred embodiment of the invention as depicted in FIG. 1. In a frame 1 of FIG. 1 there is shown a compacting water felting unit with two needle felting drums 2, 3 for processing a fiber web 8. This unit may normally be the first unit of a larger water felting layout for an unconsolidated fiber web, and therefore other felting drums (not shown) may in addition be hooked up to the frame 1, with the web 8 running in meandering manner around these additional felting drums for further processing on both sides of the fiber web 8.

The unit further includes an endless belt 4, which is passed around several rollers 5, which are tautly held and able to rotate in a support frame (not shown), while a slack portion 4′ of the endless belt 4 is brought up tangentially to the top side of the first felting drum 2. The fiber web 8 arrives from the conveyor belt 6, which can be, for example, an exit belt of a carding machine that carries the fiber web 8 on its top side. An initially bulky fiber web 8 travels on this endless belt 6 in the direction of the arrow 7, toward the unit. At the end of the conveyor belt 6, and above the conveyor belt 6, is located the slack portion 4′ of the endless belt 4, which is arranged to run in parallel with the conveyor belt 6 in the direction of the arrow 7. An unconsolidated fiber web 8 is held against the lower end of the slack portion 4′ by means of a suction box 9. Preferably, at least a partial vacuum is created on the bottom side of the slack portion 4′ of the endless belt 4 by placing the suction box 9 directly above the slack portion 4′.

The suction box 9 acts along the length of the slack portion 4′ of the endless belt 4 as far as the needle felting drum 2. As shown in FIG. 1, the slack portion 4′ lies above a rear idler roller 6′ of the endless belt 6 and the needle felting drum 2. A rear idler roller 6′ of the endless belt 6 lies roughly in the region of the front idler roller 5 of the endless belt 4 and the rear idler roller 6′ lies somewhat behind the surface of the upper needle felting drum 2. The suction box 9 holds the fiber web 8 against the lower side of the slack portion 4′, which is sealed off against the belt 4 by means of the suction box 9. At a distal end of the suction box 9, the fiber web 8 is pressed between the endless belt 4 and the drum 2 and at the same time it is wetted by means of a nozzle beam 10 operable across the width of the fiber web 8, and is needle felted by the belt 4. The liquid applied by the nozzle beam 10 is at least partly sucked away beneath the drum surface by means of a second suction box 2′, which is provided inside the needle felting drum 2. Importantly, the fiber web 8 is led down over the needle felting drum 2 in the direction of the arrow 11. The water jets from the nozzle beam 10 are acting from top to bottom, or in the direction of gravity. The handing off of the fiber web 8 from the slack portion 4′ to the drum 2 is also accomplished from top to bottom. Thus, this orientation of the nozzle beam 10, slack portion 4′ and needle felting drum 2 supports the loss-free hand-off of the still unconsolidated fiber web or felt 8 to the first needle felting drum 2, which is further coordinated with two nozzle beams 12, 13 fully capable of needle felting. In a similar fashion, a loss-free hand-off of the fiber web 8 is accomplished between the needle felting drum 2 and a second needle felting drum 3.

After processing by the second needle felting drum 3, a consolidated felt 8 can then be dried or further processed, e.g., perforated or embossed, for which a belt 14 with additional nozzle beams 15 may be optionally be provided.

As is shown by the direction of arrow 11 in FIG. 1, the two needle felting drums 2, 3 are driven to turn in opposite manner and the fiber web 8 is wound around them in meandering fashion, so that the fiber web can easily be processed on both sides. The needle felting drum 2, as well as the following needle felting drum 3, are each outfitted with one or more nozzle beams 12, 13 and suction boxes 2′, 3′ to carry out associated needle felting operations.

Claims

1. A device for hydrodynamic intertwining in order to compact the fibers of a web made from one or more of natural and synthetic fibers, the device comprising: a) an endless belt which is stretched and deflected between at least two rollers to define a slack portion of the endless belt for receiving the fiber web from a second conveyor belt,b) a first needle felting drum, coordinated with the endless belt and with at least one first nozzle beam for needle felting processing of the web on the first needle felting drum, andc) at least one second nozzle beam, having water jets that are directed against a back side of the endless belt and, through the endless belt, against the fiber web and against the first needle felting drum, at least for the wetting of same, while the endless belt is brought up tangentially to the first needle felting drum, above the conveyor belt and the first needle felting drum,d) wherein the fiber web, supported on a lower side the slack portion of the endless belt, is capable of being transferred after a first needle felting along the endless belt 4 by means of the at least one second nozzle beam downward onto the first needle felting drum,e) wherein the slack side portion of the endless belt transporting the fiber web is further coordinated with a suction box under at least a partial vacuum, the suction box being positioned above the slack portion of the endless belt and the needle felting drum, in order to support the fiber web, andf) wherein the second conveyor belt, which is supported between at least two idler rollers, transports the fiber web along a tight portion of the conveyor belt and hands the fiber web off to the slack portion of the endless belt.characterized in thatthe first needle felting drum is followed by a second needle felting drum with at least one coordinated third nozzle beam, the second needle felting drum turning in a direction opposite to a turning direction of the first needle felting drum, such that the fiber web is passed around the first and second felting drums in meandering fashion and then directed to a third endless belt for further processing.