Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G1/00—Calenders; Smoothing apparatus
  • D21G1/02—Rolls; Their bearings
  • D21G1/0233—Soft rolls
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G1/00—Calenders; Smoothing apparatus
  • D21G1/02—Rolls; Their bearings
  • D21G1/0246—Hard rolls

Definitions

• the invention concerns a roll of low-weight construction for a paper or board machine or for a paper or board finishing device.
• the invention also concerns a method for manufacture of a roll of low-weight construction for a paper or board machine or for a paper or board finishing device.
• nip rolls In nip rolls, a further problem is generally the load bearing capacity in the direction of the nip plane.
• the intermediate rolls form two nips in the nip plane, i.e. they are "pressed" from opposite directions. It is a result of such loading that the roll mantle becomes flat, i.e. the shape of the roll becomes oval.
• the roll ends since, in polymer rolls, the roll ends have been attached fixedly to the roll mantle, the roll cannot be flattened over its entire axial length in the same way, but the roll is circular in its end areas. From the point of view of the calendering profile, this is quite troublesome.
• nip rolls In nip rolls, it should be a definite aim that flattening of the roll is excluded completely, which is in many cases quite difficult to achieve, or that the flattening is uniform over the entire axial length, in which case the profile of linear load in the nip can be made uniform.
• rolls that form a nip in particular in modern centre rolls of the press sections in paper machines, which rolls have been made commonly out of a tubular roll mantle and of a suitable coating fitted onto the roll mantle, it is a problem that shell oscillation occurs in the roll. This shell oscillation may cause barring in the felts, which is again copied along with the paper to the calender rolls. In massive rock rolls, which were used earlier, shell oscillation did not occur to a corresponding extent.
• the object of the present invention is to eliminate the above problems and drawbacks related to the prior art and, further, to provide a novel roll and a method for manufacture of a roll of low-weight construction.
• the roll in accordance with the invention is mainly characterized in that the roll frame comprises a cylindrical mantle with thin walls and a core part, which fills said cylindrical mantle fully or at least partly and which has been made of a filler material that has a low weight but that endures loading in the press direction well.
• a first embodiment of the method in accordance with the invention is mainly characterized in that the roll frame of the roll is formed so that a cylindrical mantle with thin walls is manufactured and that the cylindrical mantle is filled fully or at least partly with a filler material that has a low weight but that endures loading in the press direction well, said filler material constituting the core part of the roll.
• a second embodiment of the method in accordance with the invention is mainly characterized in that the roll frame of the roll is formed out of an axle made of a tubular or solid material, out of a filler material which is fixed onto the axle, which has a low weight but endures loading in the press direction well and which forms the core part of the roll, and out of a cylindrical mantle with thin walls surrounding the core part.
• the method in accordance with the invention is very simple and easy to carry out, and, among other things, out of this reason a roll manufactured in accordance with the method is of very low cost, as compared with the rolls currently in use.
• a roll manufactured in accordance with the invention endures bending in compliance with the application of use that it has been intended for, and further, the roll receives loads in the press direction very well. If necessary, the roll can be constructed as of very low weight, in which case it can be used in a number of different applications in paper machines.
• the roll In such a roll construction, which is intended in particular for calenders, the roll can be deformed in the same way across the entire axial length of the roll.
• the advantage that is obtained is significant, for in calendering, the end flanges are exclusively detrimental as a result of edge compression, crown formation arising from heat, etc. detrimental effects.
• the strength of the coating of the roll in stead of the requirement of an equally little flattening of the tubular roll mantle as a result of the non-existent flattening of the massive end flanges.
• tubular roll mantle can be made even thinner, which reduces the weight of the roll further.
• a more extensive flattening of the roll frame can be permitted than in the prior art, which results, in the case of a nip roll, in a more extended nip, in longer nip times, in a lower maximal pressure with a certain load or, inversely, in a higher linear load with a certain level of maximal pressure.
• a construction is achieved which has no weld joints, bolt joints or tight fittings. Attenuation of vibrations in a roll with multi-layer plate construction can be accomplished readily, and the roll does not involve detrimental shell oscillation.
• the roll in accordance with the invention is simple, among other things, because, when a wound composite tube is employed at least as the outer tube, steps of manufacture of the roll frame can be combined with steps of coating.
• the bending arising from the own weight of the roll can be regulated readily by means of dimensioning of the surface plates and the filler material in a roll with multi-layer plate construction, by means of choice of materials, and, when composite materials are used, by means of choice of the fibre orientations.
• the roll in accordance with the invention is very well suited for use in connection with modernization of equipments and devices.
• Figure 1 is a fully schematic illustration of a first embodiment of the roll manufactured by means of the method in accordance with the invention.
• Figures 2A and 2B are schematic illustrations as a sectional view and as a side view in part of a further embodiment of the roll in accordance with the invention.
• FIGS 3...9 show further embodiments of the roll in accordance with the invention.
• the roll is denoted generally with the reference numeral 10.
• the frame of the roll 10 consists of a cylinder 11 with thin walls or of a corresponding cylindrical mantle and of a filler material 12 that fills said cylinder 11.
• the cylindrical mantle 11 is made of a metal material, in particular steel.
• the roll frame which consists of the cylindrical mantle 11 and of the filler material 12
• rolls ends 14 and axle journals 15 have been attached in a suitable way.
• the roll may be provided with a coating 13, which can be constructed in the desired way in respect of the material and other properties.
• the invention is very simple.
• the manufacture of the roll frame is carried out in two stages, so that first a cylindrical mantle 11 with thin walls is manufactured out of the desired material suitable for the application of use.
• this cylindrical mantle 11 is filled completely or at least partly with a material that has a low weight but that endures loading in the press direction very well.
• the filling of the cylindrical mantle 11 is carried out by casting, and the filler material is advantageously concrete.
• the cylindrical mantle 11 is measured exclusively in accordance with the requirement of bending of the roll 10, in which case a very thin cylindrical mantle 11 of low weight is obtained.
• the load applied to the roll 10 in the press direction is taken care of by means of the filler material 12, so that flattening of the roll mantle 11 is prevented, for example, by passing a nip load directly through the roll 10 from one side to the other when the roll 10 is used, for example, as an intermediate roll in a supercalender. This passing of the load through the roll 10 is carried out by means of the filler material 12.
• the filler material 12 can be optimized in respect of the cost and the weight, in which case concrete is a very good and usable alternative.
• the concrete can also be internally reinforced concrete, in particular fibre-reinforced concrete, in order that it should also tolerate a certain extent of bending.
• the whole of the roll frame consisting of a cylindrical mantle 11 and of filler material 12 can be manufactured without roll ends 14, in which case, as required, in the manufacture a pre-stressed tube can be formed whose deflection is little.
• the roll ends 14 are added to the roll frame in a later stage.
• the roll 10 may be provided with a coating 13. Since a roll 10 manufactured in accordance with the invention is suitable for use in a number of different applications of use, the roll coating 13 must, of course, be chosen in accordance with this application.
• the coating 13 is made of a polymer material.
• the coating must be suitable for this purpose, in which case, as the material of the coating 13, it is possible to use a ceramic material, metal-ceramic, or equivalent.
• Figs. 2A and 2B The method of manufacture in accordance with the invention can be modified very easily for manufacture of rolls of different types, and one such usable solution is illustrated in Figs. 2A and 2B.
• the roll is denoted generally with the reference numeral 20, and, similarly to Fig. 1, the roll frame of the roll comprises a cylindrical mantle 21, which is preferably fully, or at least partly, filled with a filler material 22, advantageously concrete.
• the roll 20 as shown in Fig. 2A is meant to be used as a heatable roll, in which case the material of the cylindrical mantle 21 is preferably steel, and it is, for example, either shell hardened or provided with a suitable hard coating, for example ceramic or metal-ceramic coating.
• Fig. 2B it is illustrated further how the heat transfer medium is introduced into the finished roll.
• a duct or bore has been formed into the axle 25, and similarly, into the roll end 24, a necessary system of ducts 27 has been formed, which communicates with the bore formed into the axle 25, on one hand, and with the pipes 26 fixed to the inner face of the cylindrical mantle 21, on the other hand.
• a water or steam coupling 28 or equivalent has been connected, by whose means the heat transfer medium is passed to the roll.
• the heating of the roll 20 is carried out in some other way, in stead of a heat transfer medium.
• electric resistors are fitted in the pipes 26, in which case the roll 20 is heated by means of electricity. Induction can also be used as the mode of heating.
• Fig. 3 shows a further embodiment of a roll in accordance with the invention, which is denoted generally with the reference numeral 30.
• the roll 30 has been manufactured as of a multi-layer plate construction so that the roll frame consists of two coaxial tubes 31,35 fitted one inside the other, between which tubes a filler material 32 has been fitted, which constitutes the core material and fills the space between the tubes 31,35 fitted one inside the other.
• the surface plates i.e. in this case the outer tube 31 and the inner tube 35, bear the loads, and the low- weight filler material 32 gives the construction a high inertia.
• the outer tube 31 that forms the cylindrical mantle of the roll it is possible to use strong materials suitable for the purpose, such as composite materials, steel, aluminum, or equivalent materials. The same materials are also suitable for materials of the inner tube 35.
• the roll may be provided with a coating 33 suitable for the purpose, which has been con- structed in the desired way in respect of the material and other properties.
• the roll 30 in accordance with this embodiment has been constructed so that the conventional end flanges of the roll are missing entirely.
• the inner tube 35 can be used as the axle of the roll 30, in the way shown in Fig. 4, from which axle the roll is mounted by means of the bearings 39.
• Figs. 5 and 6 show a further embodiment of a roll 30 as shown in Figs. 3 and 4.
• the roll 30 shown in Figs. 5 and 6 is in the other respects similar to the solution shown in Figs. 3 and 4, with the exception that in said embodiment as shown in Figs. 5 and 6 the inner tube 35a does not extend substantially beyond the axial length of the outer tube 31 in the axial direction.
• the mounting and joumalling of such a roll on the frame constructions can be accomplished, for example, in the way illustrated fully schematically in Fig. 6 by means of seats 35b fully separate from the roll, which seats are attached to the inner tube 35a in the roll frame.
• a roll as shown in Figs. 3...6 can be manufactured favourably so that, as the starting point, the inner tube 35,35a is taken, which operates as the axle of the roll.
• the tube can also be substituted for by an axle of solid material.
• a tube whose material can be, for example, a metal, plastic, carbon fibre, fibreglass, or some other composite material.
• the filler material 32 is cast/fixed, which material 32 operates as the core material of the multi-layer plate construction.
• the casting/fixing of the filler material takes place preferably when the axle tube 35,35a is positioned vertically, in which case the bending of the tube by the effect of its own weight is zero and does, thus, not constitute any problems.
• the core or filler material 32 a material is used which is of low weight and which endures loading well, for example syntactic foam.
• the filler material 32 it is also possible to use a suitable cellular material.
• the mould which may have been used for the casting, is disassembled from around the blank, and the outer face of the blank is turned in a lathe to make it coaxial with the axle tube 35,35a.
• the other surface plate of the multi-layer plate construction i.e. the outer face, which forms the cylindrical mantle 31 of the roll, can be wound onto the filler material 32 in the same way as in a normal process of coating of a polymer roll.
• the cylindrical mantle tube 31 wound onto the filler material 32 can be used directly as a base for a polymer coating 33.
• the manufacture of the roll can also be carried out so that first the inner and outer tube 35,31 of the roll frame are made fully complete.
• These can be made, for example, by winding, or it is possible to use prefabricated tubes made, for example, of a metal or of some other suitable material.
• the prefabricated inner and outer tubes 31,35 are fitted precisely coaxially one inside the other, and the filler material 32 that operates as the core material is cast between the tubes 31,35.
• filling of the outer tube or cylindrical mantle of the roll or manufacture of the roll frame in a mould can be carried out by means of centrifugal casting.
• the manufacture can take place in the vertical position or horizontally either as a continuous casting that fills the mould or, alternatively, as layers.
• As an advantage of casting taking place layer by layer it is possible to mention the control of the reaction heat of the resin that is used so that the thermal energy that has been produced in the reaction of curing has time to be removed at least partly between casting of the different layers.
• the casting of the roll frame can also be carried out in the direction of the axis of the mould layer by layer or as continuous casting so that rapidly hardening resins are utilized in the manufacture.
• the roll can also be constructed so that the inner tube is omitted completely.
• Such embodiments are illustrated, for example, in Figs. 7 and 9, in which the roll is denoted generally with the reference numeral 40.
• the outer tube 41 that forms the cylindrical mantle of the roll is manufactured, and said tube is then filled with the filler material 42 by casting.
• the manufacture can also be carried out so that a separate outside mould is used, which is filled with the filler material 42 by casting. After this, said outside mould is removed, and the cylindrical mantle 41 of the roll is formed onto the filler material 42, for example, by winding. Further, after this, the roll can be coated with a purposeful coating material.
• the seats for the axle journals 45 (Fig. 7) or for the bearings 49 (Fig. 9) are machined, and said axle journals 45 / bearings 49 can be fixed to the fastening points formed into the filler material 42, e.g. , by gluing.
• a construction of very low weight is achieved, which is fully homogeneous from end to end in the roll.
• the end flanges of the roll are entirely unnecessary, for the inner tube in the roll frame can, when necessary, operate as the axle journal, or the joumalling of the roll can be carried out by means of the inner tube by the intermediate of separate seats.
• the axle journals or bearings can be fixed directly to the filler material.
• the end flanges of the roll would be exclusively detrimental because of lateral compression, crown formation as a result of heat, etc. detrimental effects.
• Fig. 8 still shows a further alternative solution of the roll in accordance with the invention.
• the roll is denoted generally with the reference numeral 50.
• the cylindrical mantle of the roll is formed first out of a tube 51 with thin walls, whose material can be a metal, plastic, fibreglass or carbon fibre, or equivalent.
• the cylindrical tube 51 of the roll is filled with tubes 52a of thin walls and of very small diameters, as compared with the diameter of the cylindrical tube 51 , which tubes 52a are fitted substantially in the axial direction of the roll.
• the material of these small-diameter tubes 52a is, for example, metal, plastic, carbon fibre, or equivalent.
• Said tubes 52a are cast together with each other with a suitable medium, for example glue, metal, concrete, resin, micro- globules, or an equivalent material.
• a suitable medium for example glue, metal, concrete, resin, micro- globules, or an equivalent material.
• the channels formed by the longitudinal tubes 52a can be used, for example, for passing a heat transfer medium.
• the roll 50 as shown in Fig. 8 can be used, e.g., as a heatable roll in a calender.
• the medium circulating in the tubes 52a can be used for cooling of the roll 50 or for equalizing the temperature, which can be the case in calenders in the case of polymer rolls. So, the roll 50 can be provided with a coating in a way similar to what has been described in relation to earlier embodi- ments.

Landscapes

• Rolls And Other Rotary Bodies (AREA)
• Paper (AREA)
• Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
• Bending Of Plates, Rods, And Pipes (AREA)
• Cephalosporin Compounds (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Peptides Or Proteins (AREA)
• Nonmetallic Welding Materials (AREA)
• Machines For Manufacturing Corrugated Board In Mechanical Paper-Making Processes (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8549724

Family Applications (1)

Country Status (8)

Cited By (4)

Families Citing this family (3)

Citations (7)

• 1997
  • 1997-10-14 FI FI973953A patent/FI111473B/fi active
• 1998
  • 1998-10-14 WO PCT/FI1998/000800 patent/WO1999028552A1/fi active IP Right Grant
  • 1998-10-14 DE DE69828428T patent/DE69828428T2/de not_active Expired - Fee Related
  • 1998-10-14 AT AT98947589T patent/ATE286172T1/de not_active IP Right Cessation
  • 1998-10-14 JP JP2000523418A patent/JP2001525502A/ja not_active Abandoned
  • 1998-10-14 AU AU94449/98A patent/AU9444998A/en not_active Abandoned
  • 1998-10-14 EP EP98947589A patent/EP1023490B1/en not_active Expired - Lifetime
  • 1998-10-14 CA CA002305300A patent/CA2305300A1/en not_active Abandoned

Patent Citations (7)

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