JPH0229767B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a material inlet for a fiber web material and a plurality of fiber web materials having a circumferential speed that rotates in the same direction and allows the fibers to fly away under the action of centrifugal force. It has a toothed card cylinder and an air collection surface that is suctioned and continuously moved so that the fibers of the nonwoven material, which fly away from the card cylinder in a partial flow, are moved back and forth in the direction of movement of the collection surface to form a fibrous web. and hits the collection surface, and the card cylinder immediately follows in the direction of passage of the fibrous web material, such that the card cylinder provided later in the direction of passage of the fibrous web material forms a walker with respect to the card cylinder in front. , relates to a fiber web manufacturing device.

PRIOR TECHNOLOGY In such devices, the card cylinders are immediately successive, so that each subsequent card cylinder combs the fiber material fed from the previous card cylinder by the action of a walker, so that the combed fibers are removed from the combing process. It can be dropped immediately onto the collection surface. Therefore, not only is the fiber web material sufficiently defibrated, but the fiber web material can also be easily defibrated into a plurality of fiber substreams. Each subsequent card cylinder carries out an additional combing operation, so that the fiber material is made available for at least one further substream. The fiber sub-stream leaving each card cylinder therefore has only a small fiber density even with a relatively large combing throughput, which results in a high fiber web density associated with the multilayer deposition of fibers on the collecting surface. Uniformity is guaranteed. However, the opening capacity of the card cylinder is limited, despite the large throughput possible, so that the throughput speed of the fiber web material cannot be increased arbitrarily.

Problems to be Solved by the Invention Therefore, the problems that form the basis of the present invention are as follows:
The object of the present invention is to improve a device of the first type by simple means so that the speed through which the fiber web material passes or the throughput of material can be increased even further.

Means for Solving the Problem In order to solve this problem, according to the invention, each immediately following card cylinder is provided with a walker and a stripper on the circumferential side opposite to the collection surface, so that the card cylinder Covered against the collecting plane, between the covers,
A drop passageway is provided that reaches into the triangular space area between the card cylinders.

Effects of the invention Thus, according to the invention, the first card cylinder takes on all the fibers and at least this first
After the walker/stripper pair attached to the card cylinder, a considerable fiber singulation already takes place. Only a portion of these individualized fibers are thrown into the drop passage between the first card cylinder and the second card cylinder and are deposited uniformly onto the collection surface by the suction air stream. . However, fibers that are not fed through the narrow gap between the immediately following card cylinders and are delivered to a second card cylinder rotating in the same direction tend to clump together during delivery, An attached pair of walker and strippers prevents this clumping. Moreover, since the card cylinder is covered with the collection surface leaving a drop passage, the air flow that has a harmful effect on the uniform fiber layer placement on the ventilation collection surface, which is affected by the suction air flow, is prevented. can be significantly restricted.

Embodiment In order to prevent such harmful air flows, the drop passage continues to the collection surface via the guide wall of the fiber web layer already formed on the entry side of the collection surface, and on the exit side the drop path is continued through the guide wall of the fiber web layer already formed on the entry side of the collection surface. The drop path can be continued to the collection surface via a roll that rolls on. By means of the guide walls and the rolls rolling on the fiber web, the dosing channels are sealed against the space extending between them, so that the flow formation in the dosing channels is an air flow with a component parallel to the collection surface. is no longer adversely affected by The direction of rotation of the rolls, which are preferably rotatably supported on the exit side of the dosing channel, results in a roll movement in the direction of the air flow in the area of the dosing channel. On the entry side, the direction of movement of such rolls in the area of the dosing channel is opposite to the flow direction and is therefore detrimental. Therefore, only a guide wall is provided on the approach side of the collection surface,
Between this and the collecting surface the already formed fiber web layer must pass.

Ensuring sufficient sealing of the dosing channel via the guide wall for the already placed fiber web layer and ensuring unimpeded passage of the formed fiber web layer through the gap created between the guide wall and the collection surface. For this purpose, the guide wall and the collection surface can form an entry gap for the fiber web layer that tapers in the direction of movement of the collection surface.
The tapering entry gap provides a precompression of the fiber web layer, which not only makes possible a good sealing of the dosing channel, but also makes the fibers of the fiber web less susceptible to later dislocation. If the guide wall is pressed elastically against the fiber web layer on the collection surface, the compression effect can be controlled via the pressing force. Furthermore, it becomes possible to produce fiber webs of different thicknesses without modifying the equipment.

In order to ensure that the walls of the drop passage do not have a detrimental effect on the fibers flying down the wall area towards the collection surface,
In a further development of the invention, at least one suction nozzle is provided below the collection surface in the area between the two walls of each dosing channel, pointing towards the dosing channel;
Its suction opening is laterally spaced from both dosing channel walls and in the outlet area of the dosing channel. This suction nozzle ensures, at least in the area of the outlet of the dosing duct, a suction stream which extends away from the duct wall, so that the individual fibers fed to the collection surface with such a feed air stream do not reach the area of the duct wall at all. reach and therefore are not affected by the harmful effects caused by this wall.

However, due to the focusing of the feed air stream produced by the suction nozzle in the central region of the drop channel, it must be ensured that the individual fibers already deposited on the collection surface are dislocated by air eddies outside the suction area of the suction nozzle. . For this reason, it is advantageous to apply a negative pressure to the collecting surface, which retains the deposited fibers on the collecting surface, at least in the area of the exit of the dropping channel, even outside the suction nozzle on the side opposite to the dropping channel. It is. However, this negative pressure must be suitably limited so that no suction flow can occur in the drop passage that would reduce the desired focusing of the feed air stream. In order to be able to adapt it to the respective conditions, it is advantageous to make the underpressure adjustable, which is easily accomplished by means of a slide valve in the underpressure path.

To ensure unobstructed fiber loading onto the collection surface, the slope of the card cylinder tooth surface and the tooth distribution are chosen so that the focused fiber stream is dumped from the card cylinder almost vertically onto the collection surface. Do it like this. In contrast to card cylinders with the same configuration of teeth, especially in the walkers attached to the last card cylinder in the direction of passage of the fiber web material, the teeth are provided with tooth flanks with a large angle of inclination to the radial direction or with a large distribution density of teeth. It is advantageous to provide a sufficient fiber cover on the walker even with a small amount of covering fibers on the card cylinder.

Example An exemplary embodiment of the invention is shown in the drawing.

The illustrated apparatus consists essentially of a fibrous web material inlet consisting of a supply roll 1 and a boat-shaped table 2, a plurality of card cylinders 3, 4, 5, 6 in immediate succession side by side and rotating in the same direction; It has a collection surface 7 extending downwardly at intervals,
This collection surface 7 is constructed as a circulating aeration belt conveyor and can be suctioned by a suction box 8 .
In order to promote a suitable suction air from the card cylinders 3 to 6 through the collection surface 7, the card cylinders have a cover 9 against the collection surface 7, and the drop passage 10 formed between these covers 9 is , reaching the triangular space area between the card cylinders on the side closer to the collecting surface 7. These dropping passages 10 are connected to the guide wall 1 of the fiber web layer already placed on the entrance side of the collection surface 7.
1 and, on the exit side, via rolls 12 rolling on the fiber web layer, to the collection surface 7, so that in the area of the collection surface 7 these drop channels 10 are free of lateral airflow. Sealed against harmful effects. Furthermore, the area of the collection surface 7 between the drop channels 10 is rendered virtually impossible to attract by means of the insert 13, so that the fiber web layer outside the drop channel 10 is not disturbed by air eddies.

In order to ensure that the dropped fibers do not hit the air cushions that promote agglomeration and are not affected by the harmful effects of the channel walls 14, each drop channel 10 is provided with a suction box 8 below the collection surface 7. Suction nozzle 1 to be connected
5 is attached, and its nozzle opening 16 is connected to both passage walls 1.
4 and within the exit area of the dosing passage 10, the feed air stream sucked out via the suction nozzle 15 is focused, so that the fibers reach the passage wall 1.
The amount of air required for the feed air flow between the card cylinders which are sent away from the card cylinders 4 to the collection surface 7 in the area of the suction openings 16 of the suction nozzles 15, and which in each case wraps around into the drop channel, is The air is sucked in through the supply air passage 17 between the two.

Outside the suction opening 16 of the suction nozzle 15, the collection surface 7
In order to ensure that dislocation of the individual fibers already deposited on top no longer occurs, the insert piece 13 and the suction nozzle 1
5, a negative pressure is applied to the collecting surface 7 which is sufficient to retain the fibers on the collecting surface 7 but which does not have a detrimental effect on the respective drop-in channel 10. . In order to adapt the underpressure in the channels 18 to the respective conditions, these channels 18 can be connected to the suction box 8 via slide valves 19, as shown in FIG.

In order to obtain the desired effect of the suction nozzle 15,
It is important that the suction area extends at least approximately over the spreading width, and it is essential for the function that the suction area necessary for sucking out the feed air stream is formed by one or more suction nozzles. . As shown in FIG. 2, the side walls of the suction nozzle 15 can be pivoted relative to each other so that the width of the suction area can be adjusted according to the respective requirements.

Card cylinders 3 to 6 follow immediately, so
Each successive card cylinder forms a walker of the preceding card cylinder. The fiber web material supplied to the card cylinder 3 via the material inlet is
Therefore, the card cylinders 4 rotate in the same direction.
The fibers that have been partially combed by the card cylinders 4 and not captured by the card cylinders 4 are dropped into the dropping passage 10 between the card cylinders 3 and 4 and collected on the collecting surface 7.
be placed on. The fibers that are further fed through the card cylinder 4 are divided in the area of the card cylinder 5 into a partial stream to be dropped again and a partial stream to be further transferred, the latter being separated again in the area of the card cylinder 6 by a combing process.

In order to enhance the defibration of the fibrous web material, each of the card cylinders 3 to 6 is provided with a walker 20 and a stripper 2 on the circumferential side opposite to the collection surface 7.
1 is included. A portion of the covered fibers of each card cylinder is combed by the walker 20, and the fibers caught by the walker 20 are combed by the stripper 2.
1, and is again supplied to the card cylinder. Therefore, the coated fibers of each card cylinder are already defibrated before being fed to the next card cylinder, and the fibers are defibrated while simultaneously equalizing any irregularities in the fiber distribution, so that the defibration of the device is Overall ability can be significantly increased.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view of an apparatus for producing a fiber web according to the invention, and FIG. 2 is an enlarged cross-sectional view of the apparatus of FIG. 1 in the area of the dropping passage. 1, 2...Material inlet, 3-6...Card cylinder,
7... Collection surface, 20... Walker, 21... Stripper.

Claims (1)

[Scope of Claims] 1. A material inlet for the fiber web material, and a plurality of toothed card cylinders that rotate in the same direction and have a circumferential speed that allows the fibers to fly away under the action of centrifugal force;
The fibers of the fibrous web material flying away from the card cylinder in a partial flow move back and forth in the direction of movement of the collecting surface to form a fibrous web. in the case where the card cylinder immediately follows in the direction of passage of the fibrous web material, and the card cylinder provided later in the direction of passage of the fibrous web material forms a walker with respect to the card cylinder in front. A walker 20 is attached to each of the following card cylinders 3, 4, 5, and 6 on the circumferential side opposite to the collection surface 7.
and stripper 21 are included, card cylinder 3,
4, 5, 6 are covered against the collection surface 7, and between the cover 9 there is provided a drop passage 10 which reaches the triangular space area between the card cylinders 3, 4, 5, 6. Fiber web manufacturing equipment. 2. A drop channel 10 continues to the collection surface 7 via a guide wall 11 of the fiber web layer already formed on the entry side of the collection surface 7, and on the exit side the collection is carried out via a roll 12 rolling over the fiber web layer. Device according to claim 1, characterized in that it continues into the surface 7. 3. Device according to claim 2, characterized in that the guide wall 11 and the collection surface 7 form an entry gap for the fiber web layer that tapers in the direction of movement of the collection surface 7. . 4. Device according to claim 2 or 3, characterized in that the guide wall 11 can be pressed elastically against the fiber web layer on the collection surface 7. 5 At least one suction nozzle 15 is provided below the collection surface 7 in the area between the two walls 14 of the fiber part-flowing drop-in channel 10, each pointing in the direction of the drop-in channel 10, the suction opening 16 of which 3. Device according to claim 2, characterized in that it is located laterally away from the dosing channel wall (14) and within the exit area of the dosing channel (10). 6. According to claim 5, a passage 18 for applying negative pressure to the collection surface 7 is opened outside the intake opening 16 of the suction nozzle 15 and below the collection surface 7. The device described.