METHOD AND APPARATUS FOR MANUFACTURING BALES OF VOLUMINOUS FIBRE MATERIAL

Abstract: The fibre material is pre-compressed and pre-pressed in low-pressure presses (1). The pre-pressed bales are transferred by means of transportable pressing boxes (3) to a final press (9) where the bales are finally pressed while they are in the pressing box (3). The pressing box (3), therefore, is provided with an upper and a lower plate (28, 29), which are movable to and from each other. The finally pressed bale is pushed from the pressing box (3) directly into a packing and wrapping apparatus (12).

Description: Method and apparatus for manufacturing bales of voluminous- fibre material This invention relates to a method and an apparatus for manufacturing bales of voluminous fibre material, partic¬ ularly textile material. The bales are manufactured in a bale press by compressing and pressing the fibre material, normally in several steps. Thereafter each bale is packed and wrapped, which can take place in or outside the press. The Swedish patent application 7705269-. discloses a bale press of this kind. The pressing is carried out in several steps, and the final pressing of the bale takes place in a pressing chamber. The final pressing pressure thereafter is partially relieved so that the bale is permitted to expand. It is thereby possible to move the bale out of the pressing chamber to the packing and wrapping apparatus while maintaining said lower pressure, without giving rise to detrimental friction forces. Due to the fact, that the packing and wrapping apparatuses often have a higher capacity than the press, several presses could be connected to the same packing and wrapping appar¬ atus. One great problem in this connection is, that fibres of different types, for example of different colour, are pressed in the bale presses. Fibres of one type must not be ijiixed with fibres of another type. This problem limits the possibilities of arranging several presses to one packing and wrapping apparatus. A further problem is the transport from the presses to the packing and wrapping apparatus, because a pressed bale cannot be released before it is wrapped. The present invention offers a solution of the aforesaid problems, in that a special pressing box is used both for transporting the bale from a press to the packing and wrapping apparatus and for serving as final .pressing chamber. The characterizing features of the invention become appar¬ ent from the attached claims. The invention is described in greater detail in the foll¬ owing, with reference to the accompanying drawings showing an embodiment thereof, in which drawings Pig. 1 is a horizontal view of a system according to the invention, Pig. 2 shows the portion of the bale press where pre- compressing and pre-pressing take place. Pig. 3 shows a pressing box, Pig. 4 shows the pressing box connected to the bale press in Pig. 2, Pigs. show how the final press co-operates with the • J 5-7 pressing box and packing apparatus. Pig. 1 shows three low-pressure presses 1 for pre-compress- ing and pre-pressing the fibre material. These presses have low capacity and are intended to produce bales of relatively low density. The number of such presses can vary, depend¬ ing on production and capacity. On a first conveyor 2 a pressing box 3 is located. Each box 3 can be moved on the conveyor to a conveyor carriage 4, which is movable along a first track 5. Said first conveyor carriage 4 is capable to co-operate with an intermediate conveyor 6 provided to move the box 3 to a second conveyor carriage 7, which is movable along a second track 8. Adjacent said second track 8 a final press 9 is located. A pusher 10 is provided directly in front of the final press 9 and can be moved along a track 11. After the final press 9 a packing and wrapping apparatus 12 is located. An outlet conveyor 13 moves the completed bale for its further handling. Each of the low-pressure presses 1 shown in Pig. 2 is prov¬ ided with a shaft 14, into which the fibre material can "snow" down. Hereby a uniform distribution of the material across the cross-section of the shaft is obtained, so that a symmetric bale can be produced. This is essential both for the bale pressing and the subsequent handling of the bale. The material is collected on a damper 16 in a scales cont¬ ainer 15, which is supported on a scales mechanism 15A. When the scales mechanism indicates full weight, an upper damper 17 is inserted which blocks the fibre material flow to the scales container 15. The damper lβ is folded down, and the supported material drops down and fills the lower portion of the shaft. In the upper shaft new supplied material is supported by the upper damper 17. Over the material in the shaft 14 a compressing plate 18 is folded up, and at the same time the damper 16 is closed. The material is now compressed in that the plate 18 is moved downward to the upper edge of a discharge opening 19 in the side surface of the shaft. The opening 19 connects the shaft 14 to a pre-pressing chamber 20, in which a pre-pressing ram 21 is located. A vertical plate 22 maintains the opening 19 closed during ongoing compressing and pressing. The pre-compressed layers are introduced into the pre-press¬ ing chamber 20 by means of a hydraulically operated lateral- -movement plate. ' 23. Prior to this introduction the pre- -pressing ram 21 has been moved down by a hydraulic motor 24. The material, which already has been pre-pressed in the chamber 20, is prevented from falling down by means of forks 25, which can be moved into and out of the chamber 20. The aforesaid pressing operations are repeated until the desired number of pre-compressed layers have been collected in the pre-pressing chamber 20, for example 4-5 layers, depending on fibre density, bale dimensions etc. The number can be varied. When the pre-determined number of layers have been introduced into the pre-pressing chamber 20, a low density pressing and a partial relieving take place. The pressing force, for example, can be about 0.75 MN (meganewton) which is relieved to about 0,10 MN. This pre-pressed bale is now ready to be transferred to final pressing. According to the invention, this is carried out by means of a separate pressing box 3- According to the embodiment shown in Pig. 3 , the pressing box 3 consists of a frame 26 with two opposed sidewalls 27, a stationary upper plate 28 and vertically movable lower plate 29. Said lower plate 29 is guided by guide members 30. The end wall portions of the pressing box are open. At the end wall portions guide pins 31 are provided to co-operate with corresponding recesses at the discharge opening 32 of the pre-pressing chamber 20. The pressing box, thus, can be coupled together with the pre-pressing chamber 20, and retaining is effected by means of holding members 33 co-operating with recesses 34 in the pressing box. By means of a hydraulic pusher 35 the bale pre-pressed according to above can be moved from the pre-pressing chamber 20 into the box 3. As the height of the box corresponds to the space in the pre-pressing chamber 20, the bale can be transferred while maintaining the pressing force. In order to facilitate the transfer and to prevent damages on the fibres due to;'fraction against the sidewa-_lls, the distance between the opposed sidewalls 27 of the box 3 is slightly greater than the width of the pre-pressing chamber 20. After the bale transfer the box 3 is transported, y means of the different conveying means shown in Fig. 1, all the way to the final press 9. At the final press 9 the box is transported in between the pressing plates 36,37 of the final press by means of the conveyor carriage 7, on which a conveying belt 38 is provided. Furthermore, a conveyor (not shown) is provided in the final press 9 for facilitating the transport of the pressing box 3 into and out of the final press. In the final press 9 the upper pressing plate 36 is movable by means of a hydraulic motor 39• At the pressing, the upper and, respectively, lower plate 28,29 of the box 3 is coupled together with the respective pressing plate 36,37. The pressing box 3 constitutes the pressing chamber, and the lower plate 29 of the box 3 is moved along the guide members 30 toward the upper plate 28, thereby pressing the bale together. The final pressing is carried out in two steps. The movable pressing plate 36 of the press 9 first assumes a pressing position where the bale is compressed to a height lower than the final bale height, and thereafter an expansion position corresponding to the final bale height. After a desired adjustable holding time in the pressing position, the movable pressing plate 36 returns to the expansion position. The final pressing force, for example, can amount to 4 MN. The completely pressed bale is pushed out of the box 3 by means of the pusher 10. The packing and wrapping apparatus 12 preferably is located immediately adjacent the final press so that the packing material 40 forms a curtain between them. The apparatus 12 is equipped with an upper and a lower conveying path 41,42, which maintain the height of the bale and therewith the pressing force during the packing. The packing material 40 is folded about the bale when it is being pushed out and thereby envelops the leading short side, upper and lower side of the bale. Special members (not shown) fold the packing material inward against the bale. No direct contact occurs between fibres and roll conveyor, and thereby mixing of fibres in this phase is prevented. Immediately after the packing the bale is wrapped with tie wire. The wrapping unit is of conventional type and located so that the bale is compressed locally in the place where the tie wire is attached. Thereby the expansion of the bale after the wrapping is reduced. The wrapping is carried out with several wires while the bale is advanced. Transport paths are provided even after the wrapping unit, so that the bale portion already wrapped is retained under load until all wrapping wires have been attached on the bale. The complete bale thereafter is handled by the discharge conveyor 13. It is, of course, possible after the final pressing possibly to move the pressing box 3 with maintained pressing force to a packing and wrapping apparatus located at a distance from the final press 9. It is, however, essential that packing and wrapping are carried out without releasing the bale prior thereto. The present invention renders it possible to serve several low-pressure presses with one final press of high capacity. This can be effected without risk of mixing different fibres from the low-pressure presses, by using a special pressing box. The baling at older pressing lines with low capacity, furthermore, can be made more efficient and automated without too extensive reconstruction. The invention, of course, is not restricted to the embodiments shown, but can be varied within the scope of the invention idea.

Claims: Claims 1. A method of manufacturing bales of voluminous fibre material where the bales are formed of a number of pre- -compressed material layers, which are pressed together, packed and wrapped and the pre-compressed material layers comprised in a bale are subjected to a pre-pressing with subsequent limited expansion, c h a r a c t e r i z e d i , that the bale thereafter with maintained height is trans¬ ferred to a pressing box, that this pressing box is trans¬ ported to and introduced into a separate final press, that the final pressing of the bale with subsequent limited expansion is carried out while the bale is in the pressing box, and that the finally pressed bale is pushed out of the pressing box and directly packed and wrapped with maintained height. 2. A method as defined in claim 1, c h a r a c t e r i z e d i n, that the finally pressed bale is pushed out of the pressing box while the box is in the final press. 3. A method as defined in claim 1 or 2 _. c h a r a c t e r i z e d i , that the packing of the bale is carried out so that the fibre material does not come into direct contact with any conveying means outside the pressing box. 4. A method as defined in any one of the preceding claims, c h a r a c t e r i z e d i n, that pre-pressed bales from several pre-presses with associated boxes are served by the same final press. 5. An appaeatus for manufacturing bales of voluminous fibre material, comprising pre-compresεin ' g chamber and pressing chamber as well as means for packing and wrapping the bales, where a pre-pressing chamber is provided to receive and press the number of pre-compressedmaterial layers comprised in each bale, c h a r a c t e r i z e d i n, that it comprises a transportable pressing box (3) capable with maintained bale height to receive the bale from the pre-pressing chamber (20) and to transfer it to a final press (9), that the pressing box (3) comprises an upper and a lower plate (28,29), which are movable to and from each other, and the pressing box (3) constitutes the pressing chamber proper in the final press (9) . and that the packing and wrapping apparatus (12) is capable to receive the bale directly from the pressing box (3) with maintained bale height. 6. An apparatus as defined in claim 5_- , c h a r a c t e r i z e d i , that the pressing box (3) is provided with opposed sidewal (27),and the distance between the same is slightly greater than the width of the pre-pressing chamber (20). 7. An apparatus as defined in claim 5 or 6, c h a r a c t e r i z e d i n, that the final press (9) is capable to serve several pre-compressing and pre-pressing chambers (14,20) and associated pressing boxes (3). 8. An apparatus as defined in any one of the claims 5-7, c h a r a c t e r i z e d i , that the packing apparatus (12) is formed and located so that the bales are packed without the fibre material directly contacting any conveying means outside the pressing box (3) • 9. An apparatus as defined in any one of the preceding claim c h a r a c t e r i z e d i n, that the packing and wrapping apparatus (12) is provided with members for locally compressing the bale in the place where the tie wire is attached, so that the expansion of the bale after the wrapping is reduced.

Inventors: EDSTROEM STEN-ERIK, ERIKSSON ERIK HELMER, STROEMBERG NILS ERIK, EDSTROEM, STEN-ERIK, ERIKSSON, ERIK, HELMER, STROEMBERG, NILS, ERIK
Applicants: SUNDS DEFIBRATOR, SUNDS DEFIBRATOR AKTIEBOLAG
Application year: 1986
Main classification: B65B27
IPC codes: B30B9, B65B63