Method and Device For Preparing a Grand Bale of Pulp Sheet and Corresponding Grand Bale

Abstract

The invention relates to a method and device for preparing a grand bale (10) of pulp sheet or similar. The grand bale (10) of pulp sheet contains two or more pulp-sheet bales (12), each of which pulp-sheet bales (12) is bound by wrapping a web-like wrapping band (16) around the bale to bind the bale. The wrapping band (16) has a start (18) lying against the pulp-sheet bale (12) and an end (20) remaining on the surface of the wrapping band (16). 1.5 or more rounds of wrapping band (16) are wrapped around the pulp-sheet bale (12). The pulp-sheet bales (12) are placed on top of each other, in such a way that gravity forms a bond between the rounds of wrapping band (16) when they remain between two of the pulp-sheet bales (12) on top of each other in the grand bale (10). The invention also relates to a corresponding grand bale (10) of pulp sheet.

Description

The present invention relates to a method and device for preparing a grand bale of pulp sheet or similar, in which the grand bale of pulp sheet contains two or more pulp-sheet bales, each of which pulp-sheet bales is bound by wrapping a web-like wrapping band around the pulp-sheet bale, in such a way that the wrapping band has a start lying against the pulp-sheet bale and an end remaining on the surface of the wrapping band. The invention also relates to a corresponding grand bale.

A grand bale of pulp sheet, which is as such known from, for example, patent FI 105667, consists of smaller bales of pulp sheet, which weigh about 250 kg. The bales or grand bales of pulp sheet are, as is known, usually bound by steel wire or similar. The use of steel wire leads to costs and endangers work safety, both at the mill where the wire is removed and waste management arranged and at the mill where the bales are packed. In addition, the use of steel wire creates an unnecessary environmental impact. Indeed, patent application FI 923272 discloses a method and arrangement, in which a web-like wrapping band is wrapped around bales of pulp sheet. In the solution according to the patent application, a web-like material, wider that the object being wrapped, is used. The wrapping material extends beyond the end surfaces of the object and the protruding parts of the wrapping material are folded as flaps against the end surfaces. A binder agent is introduced to some of the flaps to form a bond between the flaps. However, using the method in question does not put the wrapping tightly around the pulp bale. Should a seam glued with a water-soluble glue become wet, the gluing of the wrapping material will also often open in transport. Application FI 973253 discloses the mechanical closing of the seams from the sides of the bales. When handling the bales with a fork-lift truck, they are pressed from the sides, in which there are closure areas made by gluing or mechanically. During truck handling, forces weakening the attachment act upon the closure areas, so that the wrapping bands of the pulp bales may open during handling.

The invention is intended to create a method and device, by means of which a grand bale of pulp sheets, i.e. a pulp-bale unit, can be manufactured, the use of which from packing to opening at its point of use will achieve greater overall economy. The characteristic features of the method according to the present invention are stated in claims 1-9, the characteristic features of the grand bale according to the invention are stated in claims 10-13, and the characteristic features of the device according to the invention are stated in claims 14-21. The use of the invention allows pulp-sheet bales bound with a web-like wrapping-band-to be assembled in grand bales of pulp sheets, the structure of which assists in securing the wrapping band.

A grand bale of pulp sheets contains several, for example 4, pulp-sheet bales on top of each other. In turn, two grand bales of pulp can be bound together to obtain an export unit, usually weighing 2000 kg. In the method according to the invention, the pulp-sheet bales are bound by wrapping a web-like wrapping band around each pulp bale, in such a way that the start of the wrapping band lies against the pulp bale and the end of it remains on the surface of the wrapping band. Preferably several rounds, for example, two but at least 1.5 rounds of wrapping band are wrapped around the pulp bale, so that only some of the forces tending to open the pulp bale act upon the attachment that is preferably made at the end of the band. When making a grand bale of pulp sheets, the pulp bales are packed on top of each other, in such a way that gravity creates a bond between the rounds of wrapping band when they remain between two bales that are on top of each other in the grand bale. The bond formed between the rounds of wrapping band prevents the wrapping bands from opening around the pulp bales, as long as the pulp bales remain in the grand bale of pulp sheets. The end of the wrapping band preferably remains between two pulp-sheet bales.

In one embodiment, the pulp bales are held in place using gripper members while the wrapping band is being wrapped around the pulp bale.

In one embodiment the wrapping band is kept in tension during binding. By keeping the wrapping band tensioned during binding a tighter pulp bale is obtained than when the wrapping band is loose. The pulp-bale processing line is simplified, if wrapping stations, which bind the bales by wrapping, are used instead of binding machines to bind the bales. When using wrapping band from a reel, or cut lengths of wrapping band from stacks of wrapping bands cut by a sheet cutter, a wrapping-sheet folder will not be required, as was previously the case. The bale processing line is considerably simpler than known solutions.

In one embodiment the wrapping band is a chemical-pulp or paper-pulp web, so that it can be pulped along with the pulp-sheet bale. In one preferred embodiment, the wrapping band is of the same material as the pulp-sheet bale and is made using the sheet cutter of the same machine, without a slitter-winder.

In one embodiment the wrapping band is glued for at least part of the distance for which it overlaps itself, thus forming a glued attachment. The glued attachment is used to ensure that the wrapping band will remain attached before the bales are stacked on top of each other.

In one embodiment the wrapping band is attached mechanically to the wrapping band or pulp-sheet bale for at least part of the length of the wrapping band. The mechanical attachments are formed, for example, by pressing the pulp-sheet bale with a cut-and-crease platen press creating a mechanical attachment, in such a way that the outer wrapping-band layers are pressed into the surface of the pulp-sheet bale. When using a mechanical attachment, adhesive does not enter the papermaking process along with the pulp bales. An adhesive sticker can also be used in the attachment. In one embodiment adhesive and a mechanical attachment are used, which will create a very durable attachment of the wrapping band of the pulp-sheet bale. An adhesive sticker can also be used with the above solutions when creating various attachment combinations.

In one embodiment the edges of the wrapping band are turned over two (or more) times. The edge fold reduces the risk of edge tearing and increases tensile strength.

In the following, the invention, particularly the grand bale and the device, is examined in greater detail with reference to the accompanying drawings showing some applications of the invention, in which

FIG. 1 shows a pulp-sheet bale according to the invention,

FIG. 2 shows a grand bale of pulp sheets according to the invention,

FIG. 3 shows a pulp-sheet bale according to the invention, around which a wrapping band is wrapped in both directions,

FIG. 4 shows a pulp-sheet bale according to the invention, the wrapping band around which has folded edges,

FIG. 5 shows the device according to the invention for binding pulp-sheet bales, as well as four pulp-sheet bales stacked to form a grand bale of pulp sheets,

FIG. 6 shows a wrapping station according to the invention, when using a wrapping band from a reel,

FIG. 7 shows a wrapping station according to the invention, when using ready-cut wrapping bands,

FIG. 8 shows a wrapping station according to the invention in the cross direction of the machine,

FIG. 9 shows a wrapping station according to the invention, when wrapping has ended,

FIG. 10 shows the centring of a bale using the device according to the invention,

FIG. 11 shows a bale arriving at the wrapping station in the device according to the invention,

FIG. 12 shows the winding of the wrapping band using the device according to the invention,

FIG. 13 shows the situation after the completion of the winding of the wrapping band using the device according to the invention,

FIG. 14 shows the cutting of the wrapping band and the spraying of adhesive using the device according to the invention,

FIG. 15 shows the feed of the wrapping band into the lower pocket to await the arrival of the next bale of pulp sheets using the device according to the invention.

FIG. 1 shows a pulp-sheet bale 12 according to the invention. Grand bales 10 (FIG. 2) of pulp sheets consist of pulp-sheet bales 12 of this kind. The pulp-sheet bale 12 is wrapped in a web-like wrapping band 16, in such a way that the wrapping band 16 has a start 18 lying against the pulp-sheet bale 12 and an end 20 remaining on the surface of the wrapping band 16. In one embodiment, the width w of the wrapping band is essentially of the same order of magnitude as the breadth b of the pulp-sheet bale, the width of the wrapping band being 70-100%, preferably 85-100% of the breath b of the pulp-sheet bale being wrapped.

FIG. 2 shows a grand bale 10 of pulp sheets according to the invention, which includes two or more, generally 2-10 and preferably 3-5 pulp-sheet bales 12. In FIG. 2, the pulp-sheet bales are shown as if they were separate in order to clarify the figure, even though the bond according to the invention arises when the upper pulp-sheet bales press on the wrapping bands between the bales. In the case in the figure, there are 4 pulp-sheet bales 12 on top of each other in the grand bale 10 of pulp sheets. Around each pulp-sheet bale 12 are wrapped 1.5 or more rounds, generally 1.5-5 rounds, and preferably 2-4 rounds of wrapping band 16. When there are two layers of wrapping band 16 on top of each other between the pulp-sheet bales 12, the wrapping band 16 cannot break loose nor can the pulp-sheet bales 12 break open. The layers of wrapping band 16 are thus locked between the pulp-sheet bales 12, by exploiting gravity. When the end 20 of the lowest pulp-sheet bale 12 is on the upper surface of the bale 12 or on the upper part of the side of the bale 12, the joint at the end of the wrapping band cannot become wet. This is very important when using water-soluble adhesives. Preferably the end 20 of the wrapping band 16 remains between the two uppermost pulp-sheet bales 12 in the grand bale 10 of pulp sheets, in which case the wrapping band 16 will not flap loosely. A small amount of looseness will not, however, cause problems when handling the bales, so that the very end can protrude from between the bales, as long as the rounds of the wrapping band 16 are locked. Placing the end of the wrapping band 16 between the pulp-sheet bales 12 helps the binder agent to hold the end of the wrapping band 16 attached in the pulp-sheet bale, so that the end of the wrapping band will not flap loosely. Though in the figure wrapping bands of slightly different length are drawn around the pulp-sheet bales in slightly different arrangements, when pulp-sheet bales are bound they are preferably bound essentially uniformly with each other.

In one embodiment the wrapping band is arranged around a tight pulp-sheet bale, in order to compress the pulp-sheet bale and thus to keep it tight. The wrapping band of wood fibre can be pulped along with the pulp-sheet bale, so that the wrapping band need not be removed at the paper mill and one major work stage is avoided. The pulpability of the wrapping band gains considerable advantages in both economy and work safety. In one preferred embodiment the wrapping band is of the same material as the pulp-sheet bale itself, so that it can be sold as pulp to the mill. When the wrapping band is of wood fibre or preferably of the same material as the pulp-sheet bale its amount can be increased, without increasing the waste of material. There will be no waste of material, because only dirtied wrapping band need be removed.

FIG. 3 shows a pulp-sheet bale 12 according to the invention, around which a second wrapping band 46 is wrapped on top of the wrapping band 16. By wrapping the wrapping bands 16, 46 in both directions, i.e. crosswise to each other, the pulp-sheet bale 12 is protected better and the binding is tighter. The start 18 of wrapping band 16 lies against the pulp-sheet bale while its end 20 is under wrapping band 46. The start 48 of wrapping band 46 lies against the outermost layer of wrapping band 16 while its end 50 is on the surface of the wrapping band 46. When forming a grand bale of pulp sheets from bales wrapped with two wrapping bands 16, 46, the end 50 of wrapping band 46 is preferably located between the pulp-sheet bales 12 set on top of each other. What is essential is that the layers of the outermost wrapping band 46 are locked by gravity, even though the end 50 of the wrapping band 46 may not be between the pulp-sheet bales set on top of each other.

The end 20 of wrapping band 16 can be preferably located in a grand bale of pulp sheets between the same pulp-sheet bales 12 as the end 50. In one embodiment the pulp-sheet bale can be bound very many times using wrapping band 16, which is closer to the pulp-sheet bale and, for example, two times with the outer wrapping band 46. In that case, strength will be obtained from the multi-layer wrapping band 16 while the outer wrapping band 46 will protect the pulp-sheet bale 12 and part of the wrapping band 16. Should dirtying occur, only the outer layer need be removed and the material loss will be very small. If the wrapping bands 16, 46 around the pulp-sheet bale 12 become badly dirtied, they can both be removed, in which case the actual pulp-sheet bale 12 will not be dirtied. When using two wrapping bands, the pulp-sheet bale will be very well protected and it will be simple to remove only the necessary amount of possibly dirtied wrapping band. The use of two wrapping bands thus assists in reducing loss of material.

FIG. 4 shows a pulp-sheet bale 12 according to the invention, the edges 36 of the wrapping band 16 around which are turned two (or more) times. The width of the turned edges is typically 2-6%, preferably 3-5% of the width of the wrapping band.

The width of the turned edges is typically 2-6 cm, preferably 3-5 cm. By turning the edges 36 the breaking strength of the edge of the wrapping band 16 is increased, so that the edge of the wrapping band 16 will withstand more than before without tearing. The increased breaking strength of the edges 36 of the wrapping band 16 will prevent the wrapping band from tearing in situations in which there is a tear, gap, or other fault in the edges 36 of the wrapping band 16. The folding of the wrapping band 16 thus increases the breaking strength of the edges 36 of the wrapping band 16. If the wrapping band 16 is manufactured advantageously using the same machine as the pulp sheets, there may be edge tatters at the sides of the wrapping band 16, as edge tatters are of no consequence in an actual pulp sheet. The turning of the edges 36 creates a situation, in which the edge tatters are also of no consequence in the wrapping band 16. The removal of possible edge tatters by turning them at the edges 36 of the wrapping band 16 creates a situation, in which it is practical to use as the wrapping band 16 the same material as that of the pulp sheets in the pulp-sheet bales 12. The manufacture of the wrapping band requires no special devices, instead the same drying machine and sheet cutter that is used for the pulp sheets can be used. As the wrapping band is of the same material as the pulp sheets, it can also be sold to the mill as pulp.

FIG. 5 shows the device according to the invention for binding pulp-sheet bales and stacking them to form a grand bale 10 of pulp sheets. The device includes a jig unit 26, which is used to assemble the pulp-sheet bales 12 into a grand bale 10 of pulp sheets. The jig unit 26 can be a tipping device or a stacking device. In a tipping device, the bales are first assembled next to each other and then tipped upright, thus forming a grand bale of pulp sheets. The grand bale of pulp sheets can be made using a bale stacker, which stacks the pulp-sheet bales on top of each other. At the wrapping station 22, the web-like wrapping band 16 is wrapped around the pulp-sheet bales to bind them, in such a way that the start of the wrapping band lies against the pulp-sheet bale and its end remains of the surface of the wrapping band 16. When wrapping the wrapping band around a pulp-sheet bale, the pulp-sheet bale is rotated by a bale rotator 33 around the central axis 35 of the pulp-sheet bale 12 in the machine's transverse direction. A conveyor 24 transports the pulp-sheet bales 12 to the wrapping station 22 and from it to the jig unit 26. At the wrapping station 22, there are tensioning elements 28, 32, which are arranged to tighten the wrapping band 16 when wrapping the pulp-sheet bales 12 and to maintain the tension after the cutting of the wrapping band 16. Before the pulp-sheet bales arrive at the wrapping station, where the bales are bound by wrapping, a press can be used advantageously to compress the pulp-sheet bales. The jig unit 26 is arranged to place the pulp-sheet bales 12 in the grand bale 10 of pulp sheets in such a way that the rounds of wrapping band 16 are locked by the weight of the pulp-sheet bales. The end 20 of the wrapping band 16 is preferably between two pulp-sheet bales 12, so that the weight of the pulp-sheet bales 12 prevents the wrapping band 16 from hanging loose.

FIG. 6 shows the bale rotator 33 at the wrapping station 22, which is arranged to rotate the pulp-sheet bale 12 during binding. The bale rotator 33 includes gripper members 43, 45, by means of which the pulp-sheet bale 12 is gripped to rotate it. The wrapping band 16 is kept tight during wrapping by braking the set of rollers 28, or the feed-roller pair 47, or the wrapping-band reel 52. During binding, the wrapping band 16 can be pressed towards the pulp-sheet bale 12 by a press roller 32, to tighten the wrapping band 16 as much as possible. The press roller is, however, mainly used to hold the end 20 of the wrapping band 16 tightly against the pulp-sheet bale 12 after the cutting blade 42 has cut the wrapping band 16. During wrapping, the wrapping band 16 is kept tight by a force in the longitudinal direction of the wrapping band of 0.1-1 kp/cm (in the cross direction of the web), preferably 0.2-0.7 kp/cm (in the cross direction of the web). This is 10-70%, preferably 30-50% of the tensile strength of the wrapping band. In one embodiment the pulp-sheet bale 12 can be compressed and at the same time a tight wrapping band 16 can be wrapped around it, so that the pulp-sheet bale 12 becomes very tight. The edges of the wrapping band 16 can be turned either before the wrapping band 16 is reeled onto the wrapping-band reel 52, which is then used at the wrapping-band station 22, or when unreeling the wrapping band 16 at the wrapping-band station 22, in order to wrap pulp-sheet bales 12. The edges of the wrapping band 16 can be turned using a folding unit 55 when unreeling the wrapping band 16 from the reel 52 or from a wrapping-band stack 51 (FIG. 7). The edge fold can be made using suitable guides.

FIG. 7 shows a wrapping station 22 according to the invention, when ready-cut wrapping bands 16 are used. The wrapping bands 16 are preferably cut to set lengths. In one embodiment the binding of the pulp-sheet bales 12 can be carried out using ready-cut wrapping bands 16. In that case the ready-cut wrapping bands 16 are in a wrapping-band stack 51, from where they are taken to the feed at the wrapping station 22 by a pair of feed rollers 47. When using ready-cut wrapping bands 16 for wrapping, the wrapping station 22 has a bale rotator 33 and gripper members 43, 45 and centring elements 54 (FIG. 10) corresponding to those used when using a wrapping band from a reel 52. During wrapping, the wrapping band 16 is kept tight by the pair of feed rollers 47. During wrapping, the wrapping band can be pressed against the pulp-sheet bale 12 by a press roller 32. The press roller 32 is mainly used to hold the end 20 of the wrapping band 16 tightly against the pulp-sheet bale 12 when the end 20 of the wrapping band 16 comes from the pair of feed rollers, and to ensure that the wrapping band 16 remains tight until binding is finished. The wrapping band can be used equally well from a reel and ready cut. In the other figures, the wrapping band is shown being taken from a reel, though it could equally well be taken ready cut from a wrapping-band stack 51.

FIG. 8 shows a transverse view of the bale rotator 33. The bale rotator 33 includes gripper members 43, 45. The gripper members 33 are able to grip the pulp-sheet bale 12 in the transverse direction of the wrapping unit, because the conveyor 24 is narrow. The width e of the conveyor 24 at the wrapping station is 30-60 cm. The width b of the pulp-sheet bale is 30-70% of the width e of the conveyor. The bale rotator has a drive on either both or only one side, in which case a bearing mounting will be sufficient on the other side. In the figure, there is a drive 37 on one side and a bearing mounting 39 on the other. The bale rotator 33 together with the gripper members 43, 45 can be moved away from the operating position in the transverse direction of the machine, on transfer carriages 41. In the situation in the figure, the transfer carriages 41 have been run to the operating position and the pulp-sheet bale 12 is in place awaiting the gripper members 43, 45 to take hold of it. In the figure, the wrapping band 16 is slightly narrower than the pulp-sheet bale 12. However the width w of the wrapping band is preferably wider than the distance f remaining between the gripper members in the transverse direction of the machine. The gripper members 43, 45 grip the pulp-sheet bale from a distance c, which is 5-35 cm, preferably 15-25 cm in the transverse direction of the machine. The length c of a gripper element 43, 45 is 5-25%, preferably 10-20% of the width b of the pulp-sheet bale 12. As the length c of the gripper members 43, 45 is only a small part of the with b of the pulp-sheet bale 12, they can be easily pulled away from between the layer of wrapping band once the wrapping has ended. The shape of the gripper members 43, 45 can narrow towards the centre in the thickness or width direction, or both of the gripper members 43, 45. A construction that narrows when going towards the centre of the bale will facilitate the withdrawal of the gripper members 43, 45 from between the wrapping-band layers once the wrapping has terminated.

FIG. 9 shows a wrapping station 22 after wrapping has terminated. The press roller 32 is used to hold the end 20 of the wrapping band 16 tight after the cutting of the wrapping band 16. The cutting of the wrapping band 16 can take place using the cutting blade 42. The wrapping band 16 can be attached permanently in place by gluing or mechanically. In gluing, the necessary adhesive 38 can be spread using an adhesive spray 30. The adhesive 38 is spread in the most important parts in the vicinity of the end 20 of the wrapping band 16, which in a grand bale will advantageously remain between the pulp-sheet bales 12 stacked on top of each other. After the adhesive 38 has been spread, the press roller 32 presses the end 20 of the wrapping band 16 onto the adhesive 38 and the lower layer of the wrapping band 16. The attachment of the end of the wrapping band can also be carried out mechanically, in which case the desired attachments are pressed with a stamp through the topmost layer of the wrapping band and attach the topmost layer to the lower layers of wrapping band, or to the pulp-sheet bale and the lower layers of wrapping band. The attachment of the end of the wrapping band can also be implemented by means of an adhesive sticker, which can be, for example, of tape. The sticker is preferably water-soluble.

Various combinations of gluing, stickers, and mechanical attachment can also be used, in which case very good attachments can be achieved.

Because there is at least 1.5 rounds of wrapping band around the pulp-sheet bale, part of the force opening the wrapping band will be mainly directed against the friction acting on the corners of the wrapping band, so that the adhesive attachment or mechanical attachment will not need to resist all the opening force. The adhesive attachment or mechanical attachments are preferably on the upper or lower side of the pulp-sheet bales, in which case they are not compressed during forklift truck operations, nor are unnecessary stresses cause in them by truck handling.

In connection with FIGS. 10-15, the operation of the wrapping process is described in its entirety in one preferred embodiment. In FIG. 10, the pulp-sheet bale is entering the wrapping station and in FIG. 15 the bale is leaving the wrapping station ready to be stacked in a grand bale of pulp sheets. The figures illustrate the stages in wrapping a pulp-sheet bale in numerical order.

FIG. 10 shows the centring of the pulp-sheet bale 12 before it arrives at the wrapping station 22. Centring takes place by means of centring elements 54. Centring is used to ensure that the pulp-sheet bale 12 arrives as designed between the gripper members 43, 45 in the transverse direction of the machine. The start 18 of the wrapping band 16 on the reel 52 is run down into a lower pocket 56 between two conveyors to wait for the pulp-sheet bale 12 to go to the wrapping station 22. When the pulp-sheet bale 12 goes to the wrapping station 22, it strikes the wrapping band 16 in the lower pocket 56 and the start 18 of the wrapping band 16 is caught under the bale. When the pulp-sheet bale 12 goes to the wrapping station 22, the desired portion of the wrapping band 16 remains under the pulp-sheet bale 12.

FIG. 11 shows the arrival of a pulp-sheet bale 12 at the wrapping station 22 and the mechanical stop 58 that stops it. The mechanical stop 58 goes to the lowered position once the pulp-sheet bale 12 has stopped. The desired amount of wrapping band 16 is under the pulp-sheet bale 12 when it stops at the wrapping station 22.

FIG. 12 shows the binding of the wrapping band 16 around the pulp-sheet bale 12. Once the pulp-sheet bale 12 has arrived at the wrapping station 22 between the gripper members 43, 45 as desired, the conveyor 24 at the wrapping station 22 is run down to the lowered position with the aid of a scissors table 62. The conveyor can also be run to the lowered position with the aid of articulation, not shown. When the conveyor 24 is in the lowered position, the pulp-sheet bale 12 remains on top of the lower gripper members 43. The upper gripper members 45 are lowered onto the pulp-sheet bale 12. The wrapping band 16 will then be between the pulp-sheet bale 12 and the gripper members 43, 45. After this, the wrapping band 16 is held tight in the nip 49 of the feed-roller pair 47 and the wrapping band 16 is begun to be wound around the pulp-sheet bale 12. As the wrapping band 16 is wound, the pulp-sheet bale 12 is pressed between the gripper members 43, 45. The bale rotator 33 is used to rotate the pulp-sheet bale 12 around the central axis 35 in the transverse direction of the machine. The rotation continues for the desired length of time, in order to place the desired amount of wrapping band 16 around the pulp-sheet bale 12. The wrapping band 16 is kept at the desired tension by means of a set of rollers 28, the feed-roller pair 47, and the brake of the drive 60 of the roller 52. During rotation, the gripper members 43, 45 remain between the rounds of wrapping band 16. When using a narrower wrapping band 16 than the distance between the gripper elements 43, 45, the gripper elements do not remain between the rounds of wrapping band 16. During rotation, the scissors table 62 beneath the bale rotator 22 is in the lowered position.

FIG. 13 shows the situation once the winding of the wrapping band 16 has ended. Once there is sufficient wrapping band 16 around the pulp-sheet bale 12, the winding of the pulp-sheet bale 12 is ended and the scissors table 62 is raised. The press roller 32 presses the wrapping band 16 onto the pulp-sheet bale 12, thus preventing the wrapping band 16 from slackening and unwinding. At the same time, the compressive force of the gripper members 43, 45 of the rotator 33 is released and the gripper members 43, 45 of the rotator 33 move in the transverse direction of the machine away from the pulp-sheet bale 12. The gripper members 43, 45 then come out from between the rounds of wrapping band 16.

FIG. 14 shows cutting of the wrapping band with the cutting blade 42 and the spraying of adhesive 38 by the adhesive spray 30. The adhesive 38 is sprayed by the adhesive spray 30 in the vicinity of the end 20 of the wrapping band 16, prior to the cutting of the wrapping band 16. After the cutting of the wrapping band 16, the pulp-sheet bale 12 moves forward, when the press roller 32 mangles the end 20 of the wrapping band 16 onto the adhesive 38.

FIG. 15 shows the wrapping station 22 awaiting the next pulp-sheet bale 12. When the wrapping station 22 waits for the next pulp-sheet bale 12, the wrapping band 16 waits for the next pulp-sheet bale 12 fed to the lower pocket 56 between the conveyors 24 while the next pulp-sheet bale 12 is in the centring elements 54. The wrapped pulp-sheet bale 12 is awaiting transfer to the jig unit. The mechanical stop 58 is raised to the upper position to await the arrival of the next pulp-sheet bale 12. The bale rotators 33 are driven to the operating position in the transverse direction of the machine. The gripper members 43, 45 are in the open position.

The above only describes the binding of mass bales, but it is self-evident that an entire grand bale of pulp sheets, an export unit, or both can be wrapped using known methods. The invention further relates to wrapped and unwrapped grand bales of pulp sheets, which contain pulp-sheet bales wrapped and placed as described above. The method according to the invention is suitable for use with bales of many different sizes. The size of bales that can be wrapped using the method varies widely from 100-2000 kg, preferably from 200-500 kg. The device according to the invention can also be applied to the binding of bales of many different sizes. Thus, the device is suitable for binding pulp-sheet bales, grand bales, and export units. When pulp-sheet bales, grand bales of pulp sheets, and export units are made according to the invention, there is no need to remove the steel wires from them.

Claims

1. Method preparing a grand bale of pulp sheet or similar, in which the grand bale of pulp sheet contains two or more pulp-sheet bales, each of which pulp-sheet bales is bound by wrapping a web-like wrapping band around the bale, in such a way that the wrapping band has a start lying against the pulp-sheet bale and an end remaining on the surface of the wrapping band, characterized in that 1.5 or more rounds of wrapping band are wrapped around the pulp-sheet bale and the pulp-sheet bales are placed on top of each other, in such a way that gravity forms a bond between the rounds of wrapping band when they remain between two of the pulp-sheet bales on top of each other in the grand bale.

2. Method according to claim 1, characterized in that, when wrapping the wrapping band around a pulp-sheet bale, the pulp-sheet bale is held between upper and lower gripper members, which gripper members remain between the rounds of wrapping band for the length of the gripper members during wrapping, which gripper members are pulled away from between the rounds of wrapping band once wrapping has terminated.

3. Method according to claim 1, characterized in that when wrapping the wrapping band around a pulp-sheet bale, the wrapping band is kept tensioned in order to tighten the pulp-sheet bale.

4. Method according to claim 1, characterized in that the width of the wrapping band is essentially of the same order of magnitude as the breadth of the pulp-sheet bale, the width of the wrapping band being preferably 85-100% of the breadth of the pulp-sheet bale.

5. Method according to claim 1, characterized in that the wrapping band is glued for at least part of its overlapping length in order to secure the end, before the bales are stacked.

6. Method according to claim 1, characterized in that the wrapping band is attached mechanically to the wrapping band or pulp-sheet bale for at least part of the length of the wrapping band, in order to secure it, before the bales are stacked.

7. Method according to claim 1, characterized in that the edges of the wrapping band are turned over twice.

8. Method according to claim 1, characterized in that the wrapping band is of a pulp or paper web.

9. Method according to claim 1, characterized in that the wrapping band is of the same material as the pulp-sheet bale.

10. Grand bale of pulp sheet, which includes two or more pulp-sheet bales stacked on top of each other, each pulp-sheet bale of which is bound in a web-like wrapping band, in such a way that the wrapping band has a start lying against the pulp-sheet bale and an end remaining on the surface of the wrapping band, characterized in that 1.5 or more rounds of the wrapping band are wrapped around the pulp-sheet bale, in such a way that a bond is arranged to be formed by gravity between the rounds of wrapping band, between two of the pulp-sheet bales stacked on top of each other in the grand bale of pulp sheets.

11. Grand bale of pulp sheet, according to claim 10, characterized in that the said wrapping band is tightly around the pulp-sheet bale, in order to keep the pulp-sheet bale tight.

12. Grand bale of pulp sheet, according to claim 10, characterized in that the said wrapping band is of the same material as the pulp-sheet bale itself.

13. Grand bale of pulp sheet, according to claim 10, characterized in that the edges of the wrapping band around the said pulp-sheet bales are turned over at least twice.

14. Device for preparing grand bales of pulp sheet or similar, which grand bales of pulp sheet are arranged to contain pulp-sheet bales, which device includes a jig unit, by means of which grand bales of pulp sheet are arranged to be assembled from pulp-sheet bales; a wrapping station, by means of which a web-like wrapping band is arranged to be wrapped around the pulp-sheet bale, in such a way that the wrapping band has a start lying against the pulp-sheet bale and an end remaining on the surface of the wrapping band; and conveyors, which are arranged to carry the pulp-sheet bales to the wrapping station and forwards to the jig unit, characterized in that the wrapping station and the jig unit are arranged to form a grand bale, in such a way that the wrapping band is bound between the pulp-sheet bales also by the gravity acting on the upper pulp-sheet.

15. Device according to claim 14, characterized in that the wrapping station has tensioning elements, which are arranged to tighten the wrapping band when wrapping a pulp-sheet bale and to maintain the tension after the cutting of the wrapping band.

16. Device according to claim 14, characterized characterized in that the said jig unit is arranged to place the end of the wrapping band between two pulp-sheet bales in the grand bale of pulp sheet.

17. Device according to claim 14, characterized in that the wrapping station has an adhesive spray, which is arranged to spray adhesive to secure the end of the wrapping band.

18. Device according to claim 14, characterized in that the wrapping station has a mechanical closing device, which is arranged to form mechanical attachments in the material of the wrapping band and the pulp-sheet bale.

19. Device according to claim 17, characterized in that the tensioning elements include a press roller, which is arranged to keep the end of the wrapping band tight while the mechanical closing device is making the attachments, or to press the wrapping band onto the adhesive, one the adhesive spray had sprayed the adhesive.

20. Device according to claim 14, characterized in that the tensioning elements include a set of rollers, which is arranged to tension the wrapping band while the pulp-sheet bale is being wrapped.

21. Device according to claim 14, characterized in that the wrapping station has a bale rotator, which includes gripper members, which are arranged to hold the pulp-sheet bale during wrapping.