WO2003084814A1

WO2003084814A1 - Method and apparatus for wrapping a roll of material and a wrapping

Info

Publication number: WO2003084814A1
Application number: PCT/FI2003/000250
Authority: WO
Inventors: Harri Paasikivi
Original assignee: Raumaster Oy
Priority date: 2002-04-05
Filing date: 2003-04-01
Publication date: 2003-10-16
Also published as: FI20020658A0; EP1492709B1; DE60314243D1; DE60314243T2; ATE364012T1; FI20020658A; FI115043B; EP1492709A1; AU2003219197A1

Abstract

This invention relates to a method and an apparatus (2) for wrapping a roll of material (1), in particular a roll of paper, and a wrapping (40) made therewith. In the method, the side surface (41) and the ends of the roll (1) are first covered with a base wrapper web (42) according to the prior art, head discs (45, 48), roll end wrapper webs (46, 49) wound at the ends of the side surface (41) of the roll. An outer wrapper web (52), made of deformable film, is wrapped onto the base wrapper web (42) and roll end wrapper webs (46, 49) in such a way that an axial overhang (53, 54) is created at both ends (43, 44) of the roll (1), which overhang folds over onto the roll end surface (43, 44), over the said head disc (45, 48).

Description

Method and apparatus for wrapping a roll of material and a wrapping

The present invention relates to a method and an apparatus for wrapping a roll of material and a wrapping in accordance with the preambles of the independent claims presented below. The invention in particular concerns a novel spiral combi-wrapping method that can be used, for example, for wrapping a paper roll.

In various industries, for example in the paper and textile industries, finished rolls of material are wrapped in a protective wrapping, the purpose of which is to protect the easily damaged roll of material from mechanical surface damage and environmental influences, in particular from air humidity, during storage, handling and transportation.

In the paper industry, the diameter of finished paper rolls ready to be wrapped is typically approximately 0,5-2,5 m and the width typically approximately 0,5-A m. The roll dimensions within mills vary between different production batches.

Known wrapper materials for wrapping a roll include, for example, paper, laminate, deformable plastic film and various plastic cushionings, such as plastic foams and bubble films. Paper wrapping, the use of which is known, for example, from the publication EP 0765809, gives a roll of material good mechanical protection. The beneficial properties of such a wrapper include, among other things, strength, rigidity, resistance to abrasion, hygroscopicity, good availability and reasonable price. A weakness of paper wrapping is low protection from humidity.

Laminate, the use of which as wrapper material is known, for example, from the patent application FI 882932, typically consists of two layers of paper, between which layers there is a thin plastic film. Therefore, the laminate gives good mechanical protection combined with good protection from humidity. A problem of laminate wrapper is, however, its relatively high price and difficult recyclability. Separation of the plastic film from the layers of paper is very difficult and uneconomical, for which reason used laminate wrappers usually have to be disposed of by burning.

Deformable plastic film, the use of which is known, for example, from the patent FI 82011, has the benefit of providing good protection from humidity. However, the mechanical protection given by deformable film is low.

The use of a wrapper made of plastic cushioning, for example plastic foam or bubble film, is known, for example, from the publication US 5131209. The foremost benefit of cushioned wrapper is good protection from impacts. In other respects, the mechanical protection afforded by it is often not sufficient, and also protection from humidity is deficient mainly because it is difficult to render the seams of a cushioned wrapping tight.

It is therefore a weakness of all wrapping methods based on single wrapper material, except for laminate wrapping, that, depending on the wrapper material, either the mechanical protection or protection from humidity is poor.

Guiding the wrapper web onto the perimeter of the roll to be wrapped following a helical path and preferably in such a way that adjacent layers of wrapper stock overlap with each other, i.e. so-called spiral wrapping, is known for example from the patent publication EP 0765809. In the method of the publication, the wrapper material is packaging paper, and the longitudinal edge of the wrapper web is guided onto the roll to be wrapped at an angle to the direction of the perimeter of the roll to be wrapped and is then guided helically around the roll to be wrapped. The helically guided wrapper web terminates at both ends of the roll before the end of the roll, and in addition, a second wrapper web is wound at the roll end, which web is not helical, but parallel to the direction of the perimeter of the roll to be wrapped. The web wound at the roll end preferably overlaps with the helical wrapping and creates at the end of the roll to be wrapped an axial overhang, which is folded onto the roll end surface.

In known solutions, the axial overhangs at the ends of the roll are folded between a so-called inner head disc and an outer head disc, which discs are of the same shape as the end surface of the roll to be wrapped and which discs are attached to the roll end surface. The inner head disc is typically, for example, of relatively thick paperboard or paper, and the outer head disc is of thinner plastic-coated paper. The head discs are placed on the roll end surface in a known manner, for example, manually or by using a manipulator or a robot. The head discs are attached in known solutions with a thermal bond by using so-called head presses, the pressing force of which may typically be for example 70 kN. The heating coils of the head presses require a relatively high supply of electrical power, typically for example 30 kW for a pair of presses. Due to their great pressing force and high temperature, the head presses easily damage the ends of the rolls of material to be wrapped, which rolls are composed of heat- or pressure-sensitive paper.

The purpose of the invention presented here is to improve the known spiral wrapping method and to alleviate or even eliminate the above-mentioned problems arising in the prior art.

A method and an apparatus for wrapping a roll of material and a wrapping according to the invention are characterised by what is presented in the preambles of the independent claims presented below.

All embodiments of the invention presented in this text and their advantages refer to the method, system and wrapping according to the invention, even though this may not be explicitly stated when discussing each embodiment. In a typical method for wrapping a roll of material according to the invention, at the first stage, a base wrapper web, preferably made of paper or paperboard, is wound around the side surface of the roll, the longitudinal edge of which web is placed on the roll to be wrapped at an angle to the direction of the perimeter of the roll to be wrapped, and which base wrapper web is guided helically around the perimeter of the roll to be wrapped. Thereafter, the first inner head disc is placed on one end of the roll. Then the first roll end wrapper web, made preferably of paper or paperboard, is wound at the end of the roll in such a way that an axial overhang is created at the roll end, which overhang is folded onto the first inner head disc. Preferably, a second inner head disc is placed on the other end surface of the roll and a second roll end wrapper web, made preferably of paper or paperboard, is wrapped at the other end of the roll to be wrapped in such a way that an axial overhang is created at the other roll end, which overhang is folded onto the other inner head disc.

At the second stage, an outer head disc made preferably of damp-proof material is placed on one end of the roll, and an outer wrapper web made of deformable, preferably damp-proof film is wrapped on the side surface of the roll, which web is guided helically around the perimeter of the roll to be wrapped. The wrapping is started at one end of the roll so that an axial overhang is created at the roll end, which overhang, when the material used is deformable wrapper film, folds over onto the roll end surface, onto the outer head disc and thus secures the outer head disc in place. When the wrapping has proceeded to the other end of the roll, wrapping is terminated at this roll end in such a way that an axial overhang is created, which overhang, when the material used is wrapper film, folds over onto the roll end surface, and wrapping is interrupted here.

At a preferred third stage of a method according to the invention, a second outer head disc, typically made of damp-proof material is placed on the other end of the roll, after which a second outer wrapper web, made of deformable, preferably damp-proof film, is wound onto the perimeter of the roll at this end in such a way that an axial overhang is created, which overhang, when the material used is deformable wrapper film, folds over onto the roll end surface onto the outer head disc and thus secures the outer head disc in place.

Deformable film refers, for example, to plastic wrapper film widely used today, or other film-like material which, at least to some extent, can be stretched during wrapping without breaking its structure. After stretching, a film according to the invention tends to return to its original form. In other words, the deformation of the film is, at least in part, recoverable. Such deformable film is usually plastic film, but it can also be produced from some other material or from a combination of several materials.

The most important advantage of the invention is that the wrapping of a roll of material wrapped by the method, apparatus or wrapping according to the invention is durable and tight. The various layers of wrapper stock overlap each other in such a way that, when using damp-proof wrappers and head discs, very good protection from humidity is achieved. The advantages of the invention become particularly obvious when the roll is stored in a vertical position. In this case, moisture or other impurities that possibly enter e.g. between the outer head disc of the upper end of the roll, made of damp-proof material, and the roll end wrapper web securing the head disc exit due to gravitational force from between the roll end wrapper web and the outermost spiral wrapper.

A further advantage of the method, apparatus or wrapping according to the invention is that no head presses are needed to attach the head discs. This means lower costs and a lower need for electrical power, and, furthermore, the method, apparatus or wrapping according to the invention may be used safely, even when wrapping rolls composed of heat- or pressure-sensitive paper, the ends of which rolls are easily damaged by head presses. All head discs may also be of the same material because the outer head discs do not have to be made of material suitable for thermal bonding.

It can be mentioned as an even further advantage of the method, apparatus or wrapping according to the invention, in particular as compared with laminate wrapping, that the recycling of wrapper materials is easy because each wrapping contains only one material.

A typical apparatus according to the invention for wrapping a roll of material comprises, besides means for moving the roll of material to be wrapped, such as rollers, and means for feeding the wrapper webs, also a computer and a computer program arranged to be run in the memory of the computer, by means of which program the apparatus is controlled. The computer program of an apparatus according to the invention comprises such program code elements that cause the apparatus to wrap the roll of material handled in it in the way described above. The apparatus preferably comprises separate means for placing the base wrapper web on the roll to be wrapped as well as for placing the outermost wrapper web on the roll to be wrapped.

A typical wrapping of a roll of material according to the invention comprises a first wrapper web preferably made of paper or paper board, wound helically around the perimeter of the roll wrapped as described above, a second and preferably also a third wrapper web preferably made of paper or paperboard, at least at one end of the roll so that an axial overhang is created, which overhang is folded over onto an inner head disc. Furthermore, the wrapping comprises a first wrapper web made of deformable, damp-proof film and wound helically around the perimeter of the roll, which web is wrapped at least at one and preferably at both ends of the roll in such a way that an axial overhang is created at the roll end, which overhang is folded at one roll end over onto the outer head disc. A second wrapper web made of deformable, damp-proof film, is wound helically around the perimeter of the roll, the wrapper web being wound around the perimeter of the roll at one roll end in such manner that an axial overhang is created at the roll end, which overhang is folded over onto the outer head disc.

In a typical spiral wrapping method according to the invention and, correspondingly, in an apparatus and a wrapping according to the method, the base wrapper web and the first and the second roll end wrapper web of the roll to be wrapped are placed as follows. The base wrapper web is wound around the perimeter of the roll to be wrapped, with its longitudinal edge placed on the roll to be wrapped at a first angle to the direction of the perimeter of the roll to be wrapped. Thereafter the base wrapper web is guided helically around the perimeter of the roll to be wrapped. In addition to the base wrapper web, the first roll end wrapper web is wound around the perimeter of the roll, with its longitudinal edge placed on the roll to be wrapped at a second angle to the direction of the perimeter of the roll to be wrapped. After that, the first roll end wrapper web is guided helically around the perimeter of the roll to be wrapped. The wrapping of the first roll end wrapper web is preferably started at the end of the roll to be wrapped so that an axial overhang is created at the roll end, which overhang is folded over onto the roll end surface. The second roll end wrapper web is wound at the other end of the roll of material to be wrapped at a third angle to the direction of the perimeter of the roll to be wrapped in such a way that an axial overhang is created at the roll end, which overhang is folded over onto the roll end surface. The second and the third angle are typically equal, but slanted in different directions compared with the direction of the roll perimeter. Typically, the first angle is considerably greater than the second and third angles.

In the following, the invention is described in more detail by referring to the accompanying schematic drawings, in which Figure 1 represents a cross-sectional view of a roll wrapped by spiral wrapping according to the prior art, Figure 2 represents the roll and wrapping in Fig. 1 in a vertical position, Figure 3 is a cross-sectional view of a roll wrapped by the method according to the invention after the first stage of the method, Figure 4 is a cross-sectional view of a roll wrapped by the method according to the invention after the second stage of the method,

Figure 5 is a cross-sectional view of a roll wrapped by the method according to the invention after the third stage of the method, Figure 6 represents the roll and wrapping in Fig. 5 in a vertical position, and Figure 7 represents an apparatus according to the invention for wrapping a roll.

Figure 7 represents a preferred wrapping apparatus 2 for a paper roll 1, applicable for wrapping of rolls of material according to the invention, as seen from above. The paper roll 1 is represented by broken lines. A slide carriage 4 has been arranged to move on a frame 3, on which slide carriage has been mounted a wrapper feeder unit 5. The wrapper feeder unit 5 comprises, among others, wrapper web roll 6, the wrapper web of which is paper. A second slide carriage 7 has also been arranged to move on the frame 3, which slide carriage includes a wrapper feeder unit 8 of its own. Deformable plastic film is fed from the roll 9 of the second wrapper feeder unit 8 into the wrapping. The source of power for moving the slide carriages 4 and 7 is a motor 10. Turnable folding arms 12 of the folding station 11 are used for folding the paper wrapper web that hangs over the ends of the roll 1 to be parallel to the end surfaces of the roll 1. The roll 1 rests on a rotator roller system 13 of the apparatus 2. The roller 14 is a rotator roller, i.e. it has been arranged to be rotated by the motor 15. The roller 16 rotates freely. The apparatus in Fig. 7, i.e. mainly the slide carriages, wrapper feeder units, rotator roller system and folding station, is controlled by means of a computer (not shown in the figure) and software to be run in the computer and installed in its memory. Various kinds of rolls and the wrappings required for them may be pre-set in the software, and the operator or the automatic control system selects the appropriate wrapping program. Figures 1-6 are schematic, i.e. the dimensional relations do not correspond to the actual values. For the sake of clarity, the various layers of the wrappings have been depicted separately from each other and in exaggerated size as compared with a roll of typical size.

Figures 1 and 2 represent a roll 20 wrapped by spiral wrapping according to the prior art and the wrapping 21 of the roll. The roll 20 has been wrapped so that a base wrapper web 23 has been placed on the side surface 22 of the roll, which base wrapper web has been wound helically around the roll, starting from the first end 24 of the roll towards the other end 25 of the roll. The base wrapper web 23 does not hang over the edge of the roll 20 at either end of the roll. After the second inner head disc 26 has been placed on the other end 25 of the roll, the second end wrapper web 27 is wound onto the side surface of the other end 25 so that the web 27 partially hangs over the roll end surface 25. This axial overhang 28 at the roll end is folded by the folding arms of the wrapping apparatus to be parallel to the roll end surface 25, so as to cover the inner head disc 26. After that, the first end 24 of the roll is, correspondingly, wrapped with a first inner head disc 29 and a first roll end wrapper web 30, having an axial overhang 31. Finally, the roll ends are provided with outer head discs 32 and 33 by means of head presses according to the prior art. The base wrapper web 23, roll end wrapper webs 27 and 30 and outer head discs 32 and 33 are typically made of damp-proof material. Figure 2 indicates, however, why the protection from humidity of a wrapping 21 according to the prior art is not satisfactory. The seam 34 between the outer head disc 33 and roll end wrapper web 27 is generally not tight. When the roll 20 is stored in a vertical position, humidity and dirt may enter the wrapping through the seam 34 and further through the inner head disc 26, which is generally not water-proof, to the roll 20. The entry passage of water and dirt is depicted with an arrow in Fig. 2.

Figures 3, 4 and 5 represent three different stages of a preferred method according to the invention, by which method a preferred wrapping 40 according to the invention is arranged on the paper roll 1 with the apparatus 2 according to the invention as shown in Fig. 7, or with an equivalent apparatus. Fig. 6 represents the finished wrapping 40 represented in Fig. 5 in a vertical position, i.e. in its typical storage position.

Fig. 3 represents a roll of material 1 to be wrapped by a preferable method according to the invention after the first stage of the method. The wrapping of the roll of material 1 is started by first wrapping a base wrapper web 42 helically around the perimeter of the roll 1 to be wrapped, at least on part of the side surface 41 of the roll 1. The base wrapper web 42 is wound by starting at the first end 43 of the roll and proceeding towards the other end 44 of the roll. The base wrapper web 42 is preferably dimensioned to fit the roll 1 so that the wrapper web does not hang over the edge of the roll 1 at either end, at least not substantially. The base wrapper web 42 is wound onto the roll 1 at such an angle to the direction of the roll perimeter that, at each revolution, the web 42 overlaps itself. When the other end 44 of the roll is provided with the second inner head disc 45, the second roll end wrapper web 46 is wound at this end 44 of the roll. The edge of the roll end wrapper web 46 hangs over the other end 44 of the roll, and this axial overhang 47 is folded by the folding arms 12 represented in Fig. 7 or the like, to be parallel to the roll end surface 44, onto the inner head disc 45. Also the first end 43 of the roll is wrapped in the manner described above, providing it with the first inner head disc 48, the first roll end wrapper web 49 and folding its axial overhang 50 to be parallel to the roll end surface 43.

Fig. 4 represents a roll of material 1 to be wrapped by a preferable method according to the invention after the second stage of the method. After the situation represented in Fig. 3, the first outer head disc 51 is placed on the first end 43 of the roll 1, which head disc is typically made of a damp-proof material, such as paperboard or paper laminated with plastic. After this, a first outer wrapper web 52, made of deformable film, is wound onto the side surface 41 of the roll 1, which outer wrapper web is guided helically around the perimeter of the roll 1 to be wrapped, starting the wrapping at the said first end

43 of the roll in such a manner that an axial overhang 53 is created at this end 43. The film 52 is preferably chosen to be of such plastic film that the overhang 53 folds over to be parallel to the roll end surface 43 and at least substantially onto the first outer head disc 51, thus securing the outer head disc 51 in place. When the wrapping of the outer wrapper web 52 has proceeded to the other end

44 of the roll, wrapping is terminated in such a way that an axial overhang 54 is created also at the other roll end 44, which overhang folds over to be parallel to the roll end surface 44. The outer wrapper web 52 is preferably wound in the same way so that it overlaps itself like the base wrapper web 42. The outer wrapper web 52 is also preferably wound as represented in Fig. 4 in the same direction from the first roll end 43 towards the other roll end 44 as the base wrapper web 42. The axial overhangs 53 and 54 of the outer wrapper web are preferably arranged to be longer than the corresponding axial overhangs 50 and 47 of the roll end wrapper webs, particularly at the other end 44 of the roll, at which other end there is no outer head disc yet. The first outer wrapper web 52 preferably adheres to the inner head disc 45 of the other end as it shrinks. In this way, the wrapping and its seals are rendered as tight as possible.

Fig. 5 represents a roll of material 1 to be wrapped by a preferable method according to the invention and its wrapping 40 in finished form, i.e. after the third stage of the method. After the situation represented in Fig. 4, a second outer head disc 55 is placed on the other end 44 of the roll. After this, a second outer wrapper web 56, made of deformable film, is wound onto the perimeter of the roll 1 at the other roll end 44 in such a manner that an axial overhang 57 is created at this other end 44, which overhang folds over to be parallel to the direction of the roll end surface 44, partially onto the second outer head disc 55. The wrapping of the second outer wrapper web 56 is preferably carried out helically towards the roll end 44, as represented in Fig. 5, in the same direction as the wrapping of the first outer wrapper web 52 and the base wrapper web 42. Fig. 6 represents the finished wrapping 40 of Fig. 5 in its typical storage position, i.e. in a vertical position. Fig. 6 shows why it is preferable that the wrapper webs 42, 52 and 56 overlap in the same direction. In this way, water and dirt running downwards, the movement of which being represented by the arrow, cannot easily enter through the wrapping 40 and further to the roll 1. In particular, it is preferable that the outer head discs 51 and 55 and the outer wrapper webs 52 and 56 are made of water-proof material. In this way, it is very difficult for humidity to enter through the seams of the wrapping to the roll 1, water rather always seeks to seep out of a wrapping stored in a vertical position according to Fig. 6, as represented by the arrow in Fig. 6.

It is not intended in any way to limit the scope of the invention only to its embodiments as presented above in the description, but it may rather be varied within the scope of the inventive idea presented in the claims.

Claims

1. A method for wrapping a roll of material (1), in which method, at its first stage, - a base wrapper web (42) is wrapped on at least part of the side surface (41) of the roll (1), which wrapper web is guided helically around the perimeter of the roll (1) to be wrapped, and

- at least one end (43, 44) of the roll (1) to be wrapped is provided with an inner head disc (45, 48), - a first roll end wrapper web (46, 49) is wound at least at the said one end (43, 44) of the roll (1) to be wrapped in such a way that an axial overhang (47, 50) is created at the said roll end (43, 44), which overhang is folded over onto the said inner head disc (45, 48), characterised in that, at the second stage,

- one end (43) of the roll (1) is provided with the first outer head disc (51),

- a first outer wrapper web (52), made of deformable film, is wound onto the side surface (41) of the roll, which wrapper web is guided helically around the perimeter of the roll (1) to be wrapped, starting the wrapping at the said end (43) of the roll provided with the first outer head disc (51), in such a manner that an axial overhang (53) is created at this end (43), which overhang folds over onto the roll end surface (43), over the first outer head disc (51), and

- when the wrapping has proceeded to the other end (44) of the roll (1) wrapping is terminated at this roll end (44) in such a way that an axial overhang (54) is created at the roll end (44), which overhang folds over onto the other roll end surface (44).

2. A method according to claim 1, characterised in that the method also comprises a third stage, in which stage

- a second outer head disc (55) is placed on the other end (44) of the roll and - a second outer wrapper web (56), made of deformable film, is wound onto the perimeter of the roll (1) at the other roll end (44) in such a manner that an axial overhang (57) is created at the said other end (44), which overhang folds over onto the roll end surface (44), onto the second outer head disc (55).

3. A method according to claim 1 or 2, characterised in that, furthermore at the first stage,

- the other end (43, 44) of the roll (1) to be wrapped is provided with an inner head disc (45, 48),

- a second roll end wrapper web (46, 49) is wound at the other end (43, 44) of the roll to be wrapped in such a way that an axial overhang (47, 50) is created at the other roll end (43, 44), which overhang is folded onto the said inner head disc (45, 48).

4. A method for wrapping a roll of material (1), in which method

- at least most of the side surface (41) of the roll (1) is covered by wrapping a base wrapper web (42) around the roll (1),

- the end surfaces (43, 44) of the roll (1) are covered, are at least in part, with head discs (45, 48), and

- roll end wrapper webs (46, 49) are wound at the ends of the side surface (41) of the roll, which webs are folded in part (47, 50) against the roll end surfaces (43, 44), characterised in that an outer wrapper web (52), made of deformable film, is wrapped on top of the said base wrapper web (42) and roll end wrapper webs (46, 49), the outer wrapper web being guided helically around the perimeter of the roll (1) to be wrapped in such a way that an axial overhang (53, 54) is created at the both ends (43, 44) of the roll (1), which overhang is folded onto the roll end surface (43, 44) onto the said head disc (45, 48).

5. An apparatus (2) for wrapping a roll of material (1), which apparatus (2) comprises at least means (13-16) for moving the roll of material (1) to be wrapped, means (3-10) for placing the wrapper web on the roll (1) to be wrapped and means for controlling the apparatus, characterised in that the said means for controlling the apparatus comprise means for arranging the apparatus to operate in accordance with the method according to any of the above claims 1-4.

6. An apparatus according to claim 5, characterised in that the means for placing the wrapper web onto the roll (1) to be wrapped comprise separate means (4, 5, 6) for placing the base wrapper web and means (7, 8, 9) for placing the outer wrapper web.

7. A wrapping (40) of a roll of material, which wrapping comprises - a base wrapper web (42) wound mainly around the side surface (41) of the roll so as to advance helically and - a roll end wrapper web (46, 49) wound at least at one end (43, 44) of the roll

(1), wound around the perimeter of the roll (1) to be wrapped, characterised in that the wrapping (40) furthermore comprises a first outer wrapper web (52), made of deformable film, wound around the side surface (41) of the roll over the base wrapper web (42) and roll end wrapper webs (46, 49) so as to advance helically, the parts (47, 50) of which outer wrapper web that axially hang over the roll ends (43, 44) being folded over onto the roll end surfaces (43, 44).

8. A wrapping according to claim 7, characterised in that it comprises an outer head disc (51) at least at one end (43) of the roll, onto which outer head disc is folded the part (53) of the first outer wrapper web (52), which part axially hangs over the roll end (43).

9. A wrapping according to claim 8, characterised in that it comprises a second outer head disc (55) placed on the first outer wrapper web (52) at the other end (44) of the roll and a second outer wrapper web (56), made of deformable film, wound at the said other roll end (44), the axial overhang (57) of which second outer wrapper web that hangs over the other end (44) is folded over onto the roll end surface (44), over the second outer head disc (55).

10. A wrapping according to claim 7, 8 or 9, characterised in that the outer head disc (51, 55) and/or outer wrapper web (52, 56) are made of damp-proof material.

11. A wrapping according to any of the above claims 7-10, characterised in that the base wrapper web (42) and/or roll end wrapper web (46, 49) are made of paper or paperboard.