WO2007109911A1

WO2007109911A1 - Web guiding element in the form of a rod

Info

Publication number: WO2007109911A1
Application number: PCT/CH2007/000111
Authority: WO
Inventors: Mario Feltrin
Original assignee: Maschinenfabrik Rieter Ag
Priority date: 2006-03-24
Filing date: 2007-03-02
Publication date: 2007-10-04

Abstract

The invention relates to an apparatus on a carding machine for cotton, chemical fibres or the like, which apparatus is arranged between a doffer and two squeezing rolls and in which at least one stationary web guiding element is arranged below the doffing roll, wherein the guiding element extends over the entire working width of the carding machine.

Description

Nonwoven guiding element in the form of a rod

The invention relates to a device on a carding machine for cotton, manmade fibers u. Like., Which is arranged between a pickup and two nip rolls, and in which at least one stationary non-woven element is arranged below the take-off roll, wherein the guide element extends over the entire working width of the card.

In the first solutions for the carding machine, the nonwoven fabric was removed by the pick-up by the pick-up roller and placed free-floating and wedge-shaped in a funnel over a distance of 30 to 50 cm. Due to the high production speed of the modern high-performance card, this is no longer possible. The nonwoven is therefore combined to form a band within the picking device. This can be done with the help of upstream fleece troughs, several transverse guide rollers or transverse belt withdrawal. Either two opposing bands lead the fleece to the middle or a treadmill the resulting sliver to one side of the card. Between the take-off roll and the cross-belt take-off, some manufacturers have two superimposed smooth steel rolls. They can run unencumbered, then they are pure guide rolls or be loaded with a pressure and so as actual squeeze rolls the fleece by crushing the foreign parts nachreinigen.

By interposing these devices, the actual distance that the web must bridge is only about a quarter of the previous distance. At today's production speed, this distance would no longer form an obstacle to the fleece, even without a guide element. The guide element is especially necessary when threading at the beginning or changes in production speed. The fleece slows down and may fall or must be accompanied over the gap. For earlier solutions provided a continuous guide surface to at least halfway before. In a known device according to DE 43 28 431, the stationary element even extends substantially from the customer to the nip between the two nip rolls. As a result, the fleece from the customer to carried to the nip rolls by a continuous baffle and can not fall off.

This device has the disadvantage that at very high production or very dirty cotton, especially with honeydew contaminated material, the guide surface is very quickly contaminated. This can lead to braiding - fibers that attach in the form of long formations.

By a basically continuous, almost horizontal surface as a guide surface, the pollution is enhanced. The dirt remains on the guide surface, especially in the take-off roller, there is a risk that it no longer flows through the dirt tray flowing fleece, but like a nip would work. This can cause unwanted distortions in the fleece, which can lead to holes. The braids can also let go and cause thick spots in the band. Any irregularities in the fleece, whether pigtails, thick spots, cracks or distortions are visible in the band and will give a misalignment in the later yarn, so these are to be avoided. Since the decrease lies just after the carding zone, there are no longer any work steps that can correct errors in the acceptance again.

The invention has for its object to provide a device of the type described above, which avoids the disadvantages mentioned, which in particular directs the fleece without causing an accumulation of dirt.

The solution of this object is achieved by the characterizing features of claim 1.

By a guide element, which is arranged between the pickup and the two subsequent squeezing rollers below the take-off roll, in the form of a arranged over the working width of the pickup or the take-off roll bar with a circular cross-section, a guide element is provided which provides a minimum guide surface offers. This gives the guiding function without any action neuter deposition surface for pollution is offered. The working width is defined here as the width of the roller containing the actual clothing.

Preferably, at least one second guide element with a circular cross section is arranged between this first guide rod, which is arranged below the take-off roller, and the gap between the two downstream press rollers. This second guide rod is used primarily during threading of the web at the beginning of production or during changes in production speed. The web is then deflected over the first guide rod and pushed by the take-off roller in the direction of the gap between the two nip rolls. The movement of the web down through gravity is then collected by at least one other guide rod. This creates a cascade-like motion that prevents actual web fall and assists in the arrival of the web at the gap between the nip rolls. Even if the fleece were to arrive at the lower nip rolls just below the actual nip, threading is given because the roll will catch the fleece and carry it up. At the same time the actual contact surfaces of the guide rods are minimized with the fleece, which prevents deposition of dirt and so contamination of the fleece.

The diameter of the guide rods is chosen so that they guide the fleece properly without cutting it, with too thin guide bars this danger is greater. The function of the guide rods is not that of a knife or separator element, it is merely intended to assist the nonwoven with bridging, without providing storage space. Too large bars take away especially space, without actually achieving an additional advantage. The diameter of the guide rods is between 10 and 30 mm, preferably between 18 and 25 mm, in particular 22 mm, selected as a function of the material and the actual production speed. It may be advantageous if the diameter of the guide rods, in particular in the arrangement of a plurality of guide rods, decreases in the direction of the nip roll. Preferably, the narrowest point between the first guide rod and the take-off roller is located horizontally on the same plane as the gap between the two squeeze rollers. Additional guide rods can then be placed with their uppermost surface all in the same horizontal plane therebetween. In an alternative arrangement, the second and each further guide bar are arranged offset in the direction of the nip roll a little downwards compared to the preceding guide bar. This also creates the staircase-like or cascade-like structure, which allows an advantageous transfer of the fleece.

The guide rods can be formed as a solid rod or as a profile. Any material that is common for the card can be used, in particular steel or aluminum, but also lighter materials or plastics would be possible. The rod does not have to bear great loads or forces for its function and therefore a heavy construction is not necessary. A possible repellent layer against honeydew is to be preferred. A hardened surface also has the advantage of preventing excessive wear of the guide element. The surface of the guide element may also be provided with a honeycomb structure as disclosed in DE 103 34 758 in order to minimize friction and / or deposition.

Preferably, the guide rods are installed so that they can be quickly removed for cleaning the surface, z. B. by a rail which passes through the central axis of the rod. The rod can then simply be pushed out and in. In particular, an arrangement where the rod is arranged around the rail is advantageous. In principle, the guide rod should be fixed, in particular not be formed in a free-rotating bearing or as a shaft. A rotational movement of the guide element is not provided and not necessary for the control function. It may even have a negative effect on the clean fleece transfer, especially if a delay between the customer and the nip rolls is provided.

Distance A is the horizontal distance between the central axis of the first guide element and that of the second guide element. Distance B is the distance between the telachse of the second element and the narrowest point of the gap between the nip rolls. Preferably, the distances A and B are the same. Particularly preferably, the distance A <B, in particular the ratio A to B, 1 to 2 or 1 to 3. With more than one Leitstab between the first Leitstab and the nip roll gap, it is advantageous if the distance between the individual Elements is divided equally.

Another preferred embodiment provides that the rods, in particular the second and each further rod, are adjustably arranged so that the distance can be adjusted in relation to the first rod or the preceding element and the downstream element, in particular the downstream squeezing rollers. depending on in particular the production or the material condition. Means for the setting can z. B. by a simple solution, such as. B. a slot in the side panels, where the rod can be attached can be achieved. Preferably, the first guide rod is also adjustable in the direction of the take-off and / or take-off rollers. This setting is preferably independent of the other guide rods. On the other hand, a common adjustment of the guide rods as a whole can be provided.

In the following figures, the inventive device is explained in more detail and examples of arrangements of the guide element or the guide elements according to the present invention are given.

Figure 1 Schematic side view of a card. Figure 2 Schematic view of the discharge of the card with new guide elements Figure 3 A to C Examples of different arrangements of the guide rods

Figure 1 shows a Wanderdeckelkarde, z. B. the Rieter card C60 with a working width of 1, 5 meters, with a hopper 1. The drawing shows the general sequence in a card, on which the inventive device is to be used. Fiber flakes are transported by transport channels not shown in the figure and also by different cleaning process steps, not shown, and finally fed to the hopper 1 of the card. This passes the fiber flakes as cotton wool to the card. A feed device feeds the fiber flakes to the licker-in device 2. The licker-in device 2 opens the fiber flakes and removes part of the dirt particles. The last licker-in roller passes the fibers to the drum 3, also called card drum or drum. The drum 3 works with a revolving lid 4 consisting of many lids 5 together and this parallelized the fibers even further. The lid 5 are cleaned by a lid cleaning 6.

After the fibers have partly carried out several revolutions on the drum 3, they are removed from the drum 3 by the pickup roller 7, also called pickup. The take-off roll 8, also called a doctor roll, removes the fibers in the form of a nonwoven from the consumer, deflects them and feeds them to the squeeze rolls 10. The squeeze rollers 10 guide the web to the transverse belt 11 or the transverse bands, which put the web into a band. Finally, this is stored as a card sliver in a pot not shown in the figure in a pot. At the card drum 3 additional cleaning or separation sites are arranged, for. B. carding or separating elements with knives. Various cleaning stations have also arranged downstream suction ducts, which should forward the excreted dirt. The suction channels, which are assigned locally individual cleaning elements, are brought together on one side of the card in a central suction channel. An example of such a suction device on a card is described in EP 750059 (Rieter).

Figure 2 shows a detailed schematic representation of the acceptance area of a card. The fibers are removed from the doffer roll 7 by a take-off roll 8 and passed between two squeeze rolls 10 by means of guide rods according to the invention. At least one guide rod 13 according to the invention is arranged directly at the point where the decrease and the deflection take place by the take-off roll. A second guide rod 14 and possibly further guide rods (not shown) can be used. NEN between the first rod and the gap 15 between the squeezing rollers 10 are arranged.

Figure 3a shows the arrangement according to the invention schematically. Distance D is the distance between the axes of the take-off roll 8 and the nip rolls 10 in the nonwoven direction, wherein the gap between the take-off roll 8 and the first guide rod 13 lies on the same plane E as the Gap 15 between the nip rollers 10th

Distance A is the distance between the center axis of the first guide element 13 and that of the second guide element 14. Distance B is the distance between the central axis of the second element 14 and the narrowest point of the gap 15 between the nip rollers 10. Preferably, the distance A and B equal. Particularly preferably, the distance A <B, in particular, the ratio A to B, 1 to 2 or 1 to 3. With more than one Leitstab between the first guide rod 13 and the nip roll gap 15, it is advantageous if the distance between the individual elements is divided evenly (see example in Figure 3b).

The central axis of the individual guide rods can all be arranged in parallel on a plane which runs parallel to the plane E (see FIG. 3b). Alternatively, the central axes may also lie on a plane given by the center axis of the first guide bar 13 and the axis of the lowermost squeegee 10 (not shown), thereby creating a staircase-like arrangement.

A staircase-like effect can also be achieved by a stepwise reduction in the diameter of the guide rods in the direction of the pinch nip 15, as shown in FIG. 3b.

FIG. 3c shows how a displaceable second guide rod can be arranged. By providing a possibility of displacing the intermediate guide element in one plane (here the plane between the central axis of the first guide element 13 and that of the lower squeezing roller 10), the distance between the guide elements can be set as a function of the production speed and / or the material quality and / or degree of contamination. In particular, through a slot in the side wall, a Leitstab or more Leitstäbe be used, which simplifies the flexibility for the optimization of the process parameters.

Claims

claims

1. A device on a carding machine, wherein a guide element between a pickup (7) and two subsequent nip roll (10) below a take-off roll (8) is arranged and wherein the guide element with an upper surface of a region of the take-off roll (8) faces , characterized in that the guide element is a guide rod (13) having a circular cross-section.

2. Device on a carding machine according to claim 1, wherein between the first guide rod (13), which is arranged below the take-off roll (8) and the gap (15) between the downstream nip rolls (10) at least one second guide element (14) with a circular cross-section is arranged.

3. Apparatus according to claim 2, wherein the diameter of the guide rods (13, 14) decreases in the direction of the nip rolls (10).

4. Device according to one of the preceding claims, wherein the diameter of the guide rods (13, 14) between 10 and 30 mm, preferably between 18 and 25 mm, preferably 22 mm.

5. Device according to one of the preceding claims, wherein the upper guide surface of the Leitstabs (13) or the guide rods (13, 14) on the same plane (E) with the gap (15) between the two nip rolls (10).

6. Device according to one of claims 1 to 4, wherein the upper guide surface of the first guide rod (13) on the same plane (E) with the gap (15) between the two nip rolls (10) and the subsequent guide rod (14) or subsequent guide rods are always arranged offset from the previous Leitstabs down.

7. Device according to one of the preceding claims, wherein the guide rod (13) or the guide rods between the first guide rod (13) and the downstream element is mounted so adjustable that the distance between the guide rod and the subsequent element is adjustable.