EP0000881A1 - Method and apparatus for compressing and packaging yarn cables - Google Patents

Abstract

Method and device for pressing and packing thread cables in bale form with flexible packaging material and reinforcing tapes with the help of a box press, the press stamp of which is divided into a core stamp (4) and an outer stamp (5) surrounding it and the position of the two stamps relative to one another varies during the pressing process can be. With the holding-down device (10), when the outer punch (5) is raised again, the collar (8) made of packaging material that forms during pressing can be folded over so that it no longer impedes strapping when the outer punch (5) is lowered again.

Description

The invention relates to a method for packaging thread cables and a pressing device suitable for this method.

As starting material for the manufacture of staple fiber yarns composed of synthetic fibers are used in an ever increasing extent tow, which are converted only when yarn producers using blanker and / or Zerreißvorric ^h obligations in staple fibers. In particular, dimensionally stable cartons have proven to be useful as packaging material for such thread cables, in each of which a thread cable is inserted in zigzag paths using suitable devices. A prerequisite for the subsequent, smooth further processing of the thread cables is the very even placement, in which, for example, every twisting of zigzag layers must be avoided.

This is a major disadvantage of packaging in boxes low filling weight or density, for the dispatch of a certain amount of weight of a thread cable, therefore, a very large transport space requirement and a considerable number of packaging units are required. In addition, however, it is also of interest to the further processor to keep thread cables as long as possible in one packaging unit in order to keep the personnel costs for the new cables as low as possible.

An increase in the filling weight and associated savings in packaging material and a greater length of cable tape is possible, for example, in accordance with the process of DE-PS 12 39 656 by pressing in each inserted double layer of the thread cable. With this measure and, if necessary, with an additional pressing of the entire goods, for example in the case of polyacrylonitrile thread cables, densities of around 200 to a maximum of 300 kg / m ^{3 can be} achieved. However, these values must not be described as sufficient.

• 1. die Bauschelastizität des Kabelmaterials sprunghaft zu einer Volumenvergrößerung bei Druckentlastung führt, so daß die Kartons nicht mehr vor dem Herausquellen der Ware verschlossen werden können, und
• 2. der Innendruck des verpackten Materials so groß wird, daß die Formstabilität der Kartons nicht mehr ausreicht, um diesen Druck aufzufangen. Die Formstabilität der Kartons könnte natürlich durch zusätzliche Versteifungen, wie z.B. Anlegen von Stahlbandagen oder Verwendung von Spanndrähten verbessert werden, wobei jedoch die Kanten der Kartons besondere Schutzvorrichtungen gegenüber dem Einschneiden dieser Armierungen aufweisen müßten. Derartige Versteifungen von Kartons haben keinen Eingang in die Technik gefunden, da sie die an sich schon sehr teuere Kartonverpackung noch erheblich verteuern würden.

The thread cables to be packaged generally consist of strongly crimped individual filaments. When the cables laid in a zigzag shape are pressed together, the strong structural elasticity counteracts the pressing force. The internal pressure of the cable material on the cardboard walls increases sharply with increasing pressure. An increase in the baling pressure is not possible with the well-proven cardboard packaging because

• 1. the structural elasticity of the cable material suddenly leads to an increase in volume when pressure is released, so that the cartons can no longer be closed before the goods swell out, and
• 2. the internal pressure of the packaged material becomes so great that the dimensional stability of the cartons is no longer sufficient to absorb this pressure. The dimensional stability of the boxes could of course be increased by additional stiffening conditions, such as the application of steel bandages or the use of tension wires, but the edges of the cartons should have special protective devices against cutting these reinforcements. Such stiffeners of cartons have not found their way into technology, since they would make the already very expensive carton packaging considerably more expensive.

To increase the density of packaged, stored thread cables, two approaches have been taken so far, but they have a number of disadvantages.

For example, attempts have been made to reduce the elasticity of the goods to be packaged by steam treatment. A damping of a deposited, possibly pre-pressed material is very expensive and also associated with the risk of creating inhomogeneities in the thread material. Such steaming can only be carried out in large autoclaves, a multi-stage steam treatment expediently having to be carried out after an evacuation in order to ensure penetration of the steam to the core of the deposited goods. Even if these precautionary measures are followed, it is practically impossible to achieve a similar steam treatment of the outer zones and inner layers. It is known that such different steam treatments lead, for example, to different coloring of the material.

Another possibility for increasing the density is described in GB-PS 1 310 029. Here the thread cable to be packaged is placed in a sack made of air-permeable material, sealed with a lid made of the same material as airtight as possible and then the goods packaged in this way are evacuated. Due to the external air pressure, the goods that were not previously compressed can be compressed to approx. 35% of their original volume. The disadvantages of this procedure are: be mentioned that the pressure can not be increased in the desired manner, so that again insufficient density of the material packed in this way can be achieved. In addition, there is a risk that the initially loosely inserted cable loops will get caught in one another when the volume is reduced, since in this process the material is pressed from all sides. However, if the deposited cable loops get caught or slide into one another, this inevitably leads to difficulties in the further processing of such thread cables.

A very complex type of packaging is also described in DE-GM 7 635 849. This type of packaging does not have to be tied, but instead, adhesive connections must be made between the individual layers of this packaging, which in any case must be labor-intensive and time-consuming. The density that can be achieved must also be regarded as insufficient.

It is an object of the present invention to provide a method and suitable devices for pressing and packaging thread cables into bales with a high spatial density that can be automated as far as possible using the simplest packaging materials customary in the textile industry. High bulk density is to be understood to mean, for example, packaging of thread cables made of crimped polyacrylonitrile threads with density of approximately 500 kg / m ³ or more. The simplest and cheapest solution for packaging bales is the use of plastic foils, ribbon foils or possibly also jute fabrics and reinforcement with steel straps or wires.

Such bale packaging and the presses suitable for producing these bales have long been known for staple fibers. However, it is not possible to use these baling presses for packaging thread cables, since, for example, pressed thread cables are not sufficient for the usual lateral opening of the presses have appropriate stability. In contrast to the largely complete confusion during the pressing of staple fibers, thread cables are laid down in loops or zigzag shape in such a way that the thread cables stick together as little as possible on the sides.

The task could be solved by a novel method for packaging thread cables in bales by multi-stage pressing, which is characterized in that a pre-pressed thread cable stored in uniform layers in a box-shaped open bag made of flexible packaging material in a novel box press to a bale of high density is pressed. First of all, the open flexible packaging sack must be covered with packaging material on its top, the cable material is then pressed together by lowering the entire ram, then the pressure on the edge zones of the upper cover surface of the bale is lifted again by lifting the outer ram, the protruding packaging edges towards the center of the press chamber bent and held in this position at least until the pressing pressure in the marginal zones is adjusted to that of the core zone again by lowering the outer die. If necessary, the entire press ram can then be extended further. The bale is then reinforced in the usual way with the help of tapes, wires or the like.

The pre-pressed thread cable, which is deposited and pre-pressed in uniform, for example, zigzag-shaped layers in a box-shaped, open sack made of flexible packaging material, can be done, for example, with the aid of known storage devices according to DE-PS 12 39 656 in such a way that first the box-shaped, flexible packaging sack is placed in a support container, which is preferably has neither bottom nor lid, is inserted and the thread cable is then placed in this box sack and pressed. Then it is stored in this way and pre-pressed material is transported together with the sack and support container to the box press and the support container, which should expediently have the same cross-sectional dimensions as the packaging bag used, is then only removed before the thread cable stored in the box sack is inserted into the box press.

It is also possible to first put the thread cable in a suitable support container and press it without using a box bag and then to transport this material with the support container into the box press and then to press the stored and pre-pressed cable material into the press box. In this case the press box must contain a suitably shaped box bag.

The implementation of this method is only possible when using a box press according to the invention, in which the press die is divided into a core die and an outer die surrounding it and the position of these two dies relative to one another or that of their pressing surfaces can be varied during the pressing process.

This box press preferably has a plurality of rod-shaped or sheet-like hold-down devices in the side walls of the press box at the level of the upper cover surface of the pressed bale. These hold-down devices are embedded in the side walls of the press box and can be swiveled or pushed into the press chamber of the outer die. In order to prevent the hold-down device from touching the outer punch, the outer punch has corresponding slots or recesses. Further preferred embodiments of the box press according to the invention are described below in connection with the description of the individual figures.

Figures 1 to 1 d represent in schematic form the sequence of the individual pressing operations in the box press again.

Figures 2 and 2 a show an embodiment of a box press according to the invention, in which the position of the core punch relative to the outer punch can be varied by a pressure cylinder.

FIG. 3 shows another embodiment of the divided press ram, in which the position of the outer ram can be changed via the lever and control cylinder.

The method and the essential tasks of the device according to the invention will be explained in more detail with reference to FIGS. 1 to 1 d. In Figure 1 is the flexible box bag (1), in which the zigzag form and pre-pressed thread cable (2) is contained, the packaging material serving as lid (3) and the press box of the box press, consisting of side walls (9) and the base plate (20) reproduced schematically.

In Figure 1a, by lowering d-s of the entire ram, i.e. the core stamp (4) and the outer stamp (5), the cable material (2) strongly pressed together. The pressing surface (6) of the core punch (4) and the pressing surface (7) of the outer punch (5) lie in one plane. The side walls (9) of the box press ensure that the cross-section of the deposited cable material remains unchanged from the state according to FIG. 1 during this pressing process. In this pressing process, the packaging material of the box bag (1) is pushed together to form folds. In any case, however, a bulge of the packaging material of the box bag (1) and the lid (3) forms, which surround the outer press ram in the form of a collar (8). The formation of this collar (8) from packaging material is inevitable and cannot be eliminated, for example, even with fine-tuning the dimensions of the press ram to those of the side walls (9). If the press ram and the press box fit too tightly, there will be operational failures due to canting of the ram and / or jamming of the packaging material.

Even by raising and lowering the ram several times, this collar formation cannot be eliminated, because, due to the high internal pressure of the cable material (2), each time the ram (4,5) is raised, the structural elasticity of the material ensures that the collar (8) raised press rams (4,5) can not be bent and fixed in this position.

The collar made of packaging material practically reinforces the pressed bale, e.g. impossible with steel straps, since the grooves (18) usually provided in such presses for introducing the reinforcing material are closed by the collar (8), which usually consists of several layers of packaging material. Puncturing or cutting the collar would only be possible if all sides (9) of the press box were removed. Such a removal of the side walls would, however, lead to a bulging of the packaged material and at least to a laying of the stored cable loops, so that a perfect further processing of this material would no longer be guaranteed. In addition, however, there is a risk that the not yet armored box bag (1) could not withstand the internal pressure and would lead to the side surfaces being torn open and the individual cable loops breaking out. In any case, however, such a puncturing or cutting of the collar would be very labor-intensive, associated with a risk to the operating personnel and a possible extensive destruction of the packaging material.

According to the invention, the collar formed is eliminated in that, as shown in FIG. 1b, the pressing process is now partially canceled by raising the outer punch (5) while the core punch (4) remains in its pressing position. This division of the press punch into a core punch (4) and an outer punch (5) makes it possible to prevent the pressed material (2) from swelling out while the edge zones of the upper side of the bale and thus the collar are accessible for manipulation. In this position, the press ram according to FIG. 1 b is possible to turn the collar (8) made of packaging material on all sides by mechanical or pneumatic means towards the center of the bale. In a preferred embodiment, rod-shaped hold-down devices (10) are embedded in the side walls (9) of the box press, which can be pivoted or pushed into the press space, as was shown schematically in FIG. 1b. It is expedient to let in several such bars in each side wall of the box press, which are then connected to each other, for example, via a common shaft (11) and which allow this bar-shaped hold-down device (10) to be actuated from the outside, for example via an actuator or a pneumatic drive.

By moving the hold-down device (10) towards the center of the press, the upstanding collar (8) made of packaging material is bent and held in its bent position.

It is also possible to install air nozzles at appropriate points instead of mechanical hold-down devices. The folding of the upstanding collar (8) and its holding in this position is in this case e.g. caused by compressed air flows.

If the outer punch (5) has suitable recesses or slots (33), the outer punch (5) can now be lowered again, as shown in FIG. 1 c, so that the pressing surfaces (6) and (7) form a plane again. The hold-down devices (10) can then be fed back through the slots (33) into the side walls (9) of the box press; if necessary, re-pressing is also possible to a certain extent, but care must be taken to ensure that there is no renewed pressing Forms collar from packaging material. The compressed bale according to Figure 1 c now no longer has a protruding collar made of packaging material and is therefore easily accessible for reinforcement using steel strips, tensioning wires or the like. The banding can also be carried out using known automatic banding machines. It is possible to carry out the banding with a suitable design of the guide grooves in the side walls, the base plate and the press rams in the longitudinal direction to the side walls (9) of the pressing chamber without reducing the pressing pressure or opening one of the side walls (9) of the press got to. This procedure ensures that laying and snagging of the stored cable loops is avoided, since lateral curvature of the bales can be sufficiently prevented by the applied reinforcement.

Figure 1 d shows the finished pressed and reinforced bale.

The method described above describes the individual process stages that can be carried out with the cable press according to the invention. It must be added that the filing and pre-pressing of the thread cable can be done, for example, according to DE-PS 12 39 656 in such a way that a box-shaped packaging bag is used in a support container that has the same cross-sectional shape and size as the box bag and the press box Press has been inserted. The box bag in the support container is then filled with thread cable using the device according to DE-OS 12 39 656. Deformation of the flexible box sack during placement and pre-pressing is avoided by using a support container. The support container also serves as protection against mechanical damage during the transport of the deposited and pre-pressed material from the insertion device to the box press. The support container preferably has only 4 smooth side surfaces, ie it has no bottom and no lid. If necessary, eyelets, hooks or the like are attached to the outer walls of this support box, which handle the handling can simplify with this box, if necessary it also has clamping devices on its upper edge for holding the upper edge of the inserted flexible box bag (1). If damage to the bottom of the inserted box bag cannot be ruled out during transport of the stored and pre-pressed cable material to the box press, the use of an only inserted, easy-to-remove base plate is recommended. In the usual cable depositors, the pressures occurring on the side walls are so low, despite the pre-pressing, that the support container can be removed without difficulty before or in the box press. The packaging material used should be selected so that lateral shifting of the thread cable or bulging of the side surfaces of the box bag is avoided under these conditions. Suitable flexible packaging materials in this method are, for example, smooth films, for example made of polyethylene, but also woven fabrics made of threads, fibers and, in particular, ribbon films, which may be laminated with plastics or synthetic resins. The use of so-called ribbon films or flat yarn fabrics, which can also be laminated with a smooth film, has proven particularly useful. A packaging material made of jute fabric or another material with a staple fiber character would also be suitable, for example. The box shape of the sacks used is achieved, for example, by sewing or welding suitable film webs together.

It is not absolutely necessary that the thread cable to be packed is already placed in a suitably shaped box bag in the cable holder. In a variant of the method according to the invention, this storage can also take place directly in the support container described above, but then expediently an easily removable bottom plate should have. The deposited and pre-pressed thread material is transported together with the support container to the box press, in which case the press box of the box press must contain a suitably shaped box bag. It is possible, for example with the help of the press ram, to press the deposited and pre-pressed thread material over into the box sack after removing the base plate from the support container. However, care must be taken to ensure that this does not result in the cable loops or box bag being laid. In this variant of the method, too, care must be taken that the cross-sectional shape and size of the support container, box bag and press box should correspond to one another in order to avoid any lateral movement of the cable material during the pressing process, if possible.

The cable strength of the deposited thread cables is not restricted by the method according to the invention and the device required for this. It is possible, for example, to lay, press and pack cable thicknesses of 500,000 or even more than 1,000,000 dtex total titers without difficulty. The strength of the thread cables is generally limited by the performance of the machines in the further processing to staple fiber yarns.

A possible embodiment of the box press according to the invention is shown in Figures 2 and 2 a. According to this embodiment, the main press piston (12) is firmly connected to the outer punch (5) via a mounting plate (13) and supports (14). To the mounting plate (13), a small pressure cylinder (15) is further secured which is connected to the core chuck (4) i _Rt. The small pressure cylinder (15) has connections for hydraulic actuation (not shown). In FIG. 2, the pressure piston (16) of the pressure cylinder (15) has been moved into its one end position, in this case the pressing force of the main pressure piston (12) acts mechanically on the piston (16) of the pressure cylinder (15) via the mounting plate (13). a. In this Position, the pressing surface (6) of the core punch (4) and the pressing surface (7) of the outer punch (5) form a plane. If, on the other hand, hydraulic fluid is pressed into the pressure cylinder (15), the pressure piston of the small pressure cylinder (16) moves downward and thus also the core stamp (4) connected to it. If the main plunger (12) is retracted at the same speed as the plunger (16) is extended, the core punch (4) does not move, while the outer punch (5) follows the upward movement of the main plunger (12). In the side view of FIG. 2 a, this position of the core stamp and the outer stamp is shown in the drawing. In this position it is possible to pivot the rod-shaped hold-down device (10) around its common shaft (11) into the press room. These hold-down devices 15 were located in recesses (17) of the side walls (9) or side wall doors (22) of the box press during the first pressing process. By swiveling the lever-shaped hold-down device (10), the collar made of packaging material that forms during pressing can be folded over. If the film material used for packaging shows little or slow recovery after a bending stress, it is possible to swivel the hold-down device (10) back into the recesses (17) before lifting the pressure piston (16) and lowering the main press piston (12) the outer stamp (5) has again reached its position shown in FIG. 2. If the collar made of packing material cannot be bent over in the direction of the center of the bale, the outer punch (5) must have suitable recesses (33) which allow the hold-down devices (10) to be left in their pivoted-out position shown in FIG. 2a. even if the outer punch (5) is lowered again to the common pressing position. These recesses (33) in the outer punch (5) must be such that they allow the hold-down device (10) to pivot back even when the outer punch (5) is lowered.

After lowering the outer punch (5), i.e. after the pressing surfaces (6 + 7) are in one plane again, the bale can be tied without hindrance by a collar made of packing material. In FIG. 2, the core punch (4) has three grooves (18) and the outer punch (5) has two grooves of the same type, which allow the pressed bale to be automatically tied. Corresponding recesses (18) are also contained in the base plate (20) of the press. An arcuate guide (19) in a recess (21) in a side wall door (22) and corresponding through slots (23) in the opposite side wall (9) allow a banding without opening a side wall or door and without relieving the pressure. In FIG. 2 a, the outer punch (5) again has two grooves (18) for the strapping, while the much narrower core punch contains only one strapping groove (18).

FIGS. 2 and 2a show a possible embodiment of the hold-down device (10), which in this case is attached to a shaft (11) and can be pivoted into the press space together with this shaft. Other embodiments would be e.g. a horizontal arrangement in a corresponding recess in the side wall (9) or the press door (22) and an extension into the press space with the outer die (5) raised by mechanical or hydraulic drive devices. Such a horizontal arrangement would have the advantage that such hold-down devices (10) would only require smaller recesses (33) in the outer punch (5). With a corresponding design of the head end of the hold-down device, e.g. in spherical form, damage to the packaging material when extending the hold-down device and thereby causing the packaging collar to be folded over would be ruled out with certainty.

FIG. 3 shows another embodiment of the divided press ram. Here the main plunger (12) is direct via a hollow connecting body (24) connected to the core stamp (4). In this embodiment, the position of the outer punch (5) in relation to the position of the core punch (4) can be predetermined by a lever system (27-30). The position of the lever system is determined by the position of the piston (26) of the hydraulic drive (25). To better understand the mode of operation of this lever system, the outer press ram has been drawn in its lower end position on the left side of FIG. 3, ie here the press surface (6) of the core ram (4) and the press surface (7) of the outer ram (5) are in one level. On the right side of the figure, the outer stamp (5) was drawn in the raised position, the associated lever system is labeled (27 '- 30'). A comparison of these two positions of the outer punch and the associated lever system shown in the drawing shows that only the pins (31 or 31 ') and (32 or 32') represent fixed fulcrums of the lever system. These pins are firmly connected to the connecting body (24). During the actual pressing process, the pressing forces are transmitted from the main press piston (12) via the connecting body (24), the pin (32) firmly connected to it, as well as the triangular body (29) and the tab (30) directly to the outer punch (without the interposition of a hydraulic element) 5). The force of the hydraulic ram (25, 26) only has to be sufficient to prevent a change in position of the triangular body (29) and the tab (30).

Claims (11)

1. box press for pressing stored thread cables in bale form and packaging these bales with flat, flexible packaging material and reinforcing tapes, characterized in that the press ram is divided into a core punch (4) and an outer punch surrounding it (5) and the position of these two stamps can be varied to each other during the pressing process. 2. Box press according to claim 1, characterized in that in the side walls (9) and / or side doors (22) of the press box in the amount of the surface of the pressed bale rod and / or sheet-like hold-down device (10) are let into the press room of the outer stamp can act and that the outer stamp has corresponding recesses which prevent the hold-down from being touched by the outer stamp (5) even in the lowered state. 3. Box press according to claim 1, characterized in that rod and / or sheet-shaped hold-down devices (10) are recessed in the recesses of the outer die (5), which can act when the outer die (5) is raised in the press chamber. 4. Box press according to claim 1, characterized in that compressed air nozzles act as hold-down devices (10), which are preferably attached in the side walls (9) and / or side doors (22) of the press box. 5. box press according to claims 1 to 4, characterized in that the core stamp (4) with the main pressure piston (12) of the press directly, while the outer stamp (5) with the core stamp (4) via movable lever (27-30) connected and the position of the outer stamp (5) to that of the core stamp (4) by control cylinder (25), which can change the position of the levers (27-30) can be varied. 6. Box press according to claims 1 to 4, characterized in that the outer punch (5) directly and the inner punch (4) via a small pressure cylinder (15) with the main pressure piston (12) and the pressing surface (6) of the core punch without additional pressure in the small pressure cylinder (15) has approximately the same position as the pressing surface (7) of the outer stamp, while with additional pressure in the small printing cylinder (15) the pressing surface (6) of the core stamp protrudes from the pressing surface plane (7) of the outer stamp. 7. A method for packaging thread cables in bales of high density by multi-stage pressing, characterized in that a zigzag-shaped layers in a box-shaped, open sack made of sheet-like, flexible packaging material and pre-pressed thread cable initially covered on its top with overlapping with flexible packaging material and in a box press according to claim 1 is pressed together by lowering the entire ram, the pressure at the edge zones of the upper cover surface is lifted again by lifting the outer ram, the protruding packaging material edges are bent towards the center of the press space and held in this position, at least until the outer ram is lowered the pressure in the marginal zones is adjusted to that of the core zone and the material thus pressed and encased is then reinforced in the usual way with the help of tapes or the like. 8. The method according to claim 7, characterized in that the bending and holding the protruding edges of the packaging material before the final pressing by a plurality of rod and / or flat hold-down is effected, which can act in the press chamber of the outer punch. 9. The method according to claim 7, characterized in that the bending and holding the protruding edges of the packaging material before the final pressing is effected by blowing air against the protruding edges. 10. The method according to claims 7 to 9, characterized in that the thread cable with the help of known depositing devices in a box-shaped open bag made of flexible packaging material, which is located in a support container, is deposited and pressed and this cable material in the packaging bag together with the support container to Box press is transported and the support container is only removed in the box press before the pressing process begins. 11. The method according to claims 7 to 9, characterized in that the thread cable is stored with the help of known storage devices in a support container and pressed, the support container with the cable material is then transported to the box press and there the stored and pre-pressed cable material from the support container in the a box-shaped packaging sack is pressed and the support box can be removed before the actual pressing process.

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