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 roll frame of which roll 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 roll of low-weight construction according to the preamble of claim 1.
• Such a roll has a roll frame comprising a cylindrical mantle with thin walls and a core part which fills the cylindrical mantle partly and which has been made of a filler material.
• the roll is further provided with a continuous axle bore, into which a continuous axle is embedded.
• the ends of the axle form journals by means of which the roll is to be mounted on a support construction.
• 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 modem 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 method in accordance with the invention is mainly characterized by machining locations or spaces into the core part of the roll frame, into each end of the roll, fixing axle journals or seats which are separate from the roll itself directly into the core into said locations or spaces, by means of which axle journals or seats the roll is bearing-mounted on the support constructions, or installing roll bearings into said spaces, through which roll bearings the roll is mounted on the support constructions by means of non-rotating axle journals.
• Figure 1 is a fully schematic illustration of a reference roll manufactured by means of the method 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.
• alternative solution is suggested manufacture of the mantle out of a composite material, in particular when the roll frame is used, for example, as the frame of rolls with soft coatings in a multi-roll calender.
• 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 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. In the second stage, 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 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.
• 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 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.
• pipes 26 extending substantially in the axial direction of the roll have been fitted, which pipes have been fitted in the interior of the cylindrical mantle 21 preferably in connection with the casting of the filler material 22 and fixed to the inner face of the cylindrical mantle 21.
• the roll 20 is supposed to be heated by means of a heat transfer medium, such as water or steam, and said heat transfer medium is meant to flow in the pipes 26.
• a heat transfer medium such as water or steam
• an insulation layer which tolerates high temperatures and pressures well for example a ceramic insulation layer (not shown), can be fitted before casting of the concrete.
• 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.
• 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. 4 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 embodiments.
• the roll ends, if needed, and axle journals are attached to the roll frame that has been formed.
• the coating may be a polymer coating or alternatively a ceramic coating, a metal-ceramic coating, or equivalent.

Landscapes

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

Applications Claiming Priority (3)

Publications (2)

Family

ID=8549724

Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (5)

Family Cites Families (7)

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

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