Metso Paper Inc.

Valmet Corporation

Erkki Leinonen

Mika Viljanmaa

Pekka Koivukunnas

Pekka Linnonmaa

Pekka Kivioja

Juha Ehrola

Juha Isomets&auml;

Tapio Mäenpää

Matti Tervonen

Erkki Kiiski

Arttu Laitinen

Hannu Vuorikari

Ilkka Hiirsalmi

Pauli Kytonen

Juha Koriseva

A method and arrangement for computing and regulating distribution of linear load in a multi-nip calender. A material web is passed through the nips in a set of rolls including a variable-crown upper roll, a variable-crown lower roll and intermediate rolls positioned between the upper and lower rolls. The rolls in the set of rolls are supported so that, when the nips are closed, the bending lines of the rolls are curved downwards. When computing and regulating the linear loads, one or more of the physical properties affecting the bending of each intermediate roll under load, such as bending rigidity, mass, shape, and material properties, are taken into account. The ratio of the linear loads applied to the intermediate rolls, the weight of the rolls per se, and/or the support forces applied to the rolls are regulated so that the set of rolls is in a state of equilibrium and a predetermined state of deflection.

Method and arrangement for computing and regulating the distribution of a linear load in a multi-nip calender and a multi-nip calender

A roll end ( ) for a roll, in particular for a heatable roll, in a paper or board machine or in a finishing machine is made by a powder metallurgy process in a mold ( ) such that a duct system ( ) for a heat transfer medium is formed in connection with the manufacture of the roll end. A hot isostatic pressing process in particular is used in the manufacture.

Making a powder metal roll end for a heatable roll

The object of the invention is a thermoroll for a paper/board machine or a finishing machine, the said thermoroll comprising a shell ( ) of metallic, ceramic or composite material, the shell incorporating ducts ( ) for passing a heating medium from one axial end of the shell to its opposite end. The shell is made by means of casting or powder metallurgical methods, and the ducts ( ) are formed in the matrix material of the shell which is of metal and/or ceramic, directly in connection with manufacture. A further object of the invention is a method for manufacturing a thermoroll.

Thermoroll for a paper/board machine or finishing machine and a method for manufacturing the thermoroll

A thermoroll for a paper/board machine or a finishing machine, the thermoroll having a shell of metallic, ceramic or composite material, and the shell having ducts for passing a heating medium from one axial end of the thermoroll to the other axial end of the thermoroll. The shell is made by casting or by powder metallurgical methods, and the ducts are formed in the matrix material of the shell which is metal and/or ceramic.

Method for manufacturing a thermoroll for a paper/board machine or a finishing machine

A paper machine roll, in particular a roll for a supercalender, which includes a frame and a polymer coating on the frame. The deformability of the polymer coating on the roll increases within a certain axial distance from the middle area of the roll toward the ends of the roll in order to compensate for the deformation state of the end areas of the roll frame, which deformation state is uneven when the roll is loaded.

Roll for a supercalender and method for calendering a web

A frame structure for calenders in a paper machine in which two vertical legs are horizontally connected to one another. The calender rolls are mounted, one above the other, between the vertical legs so that the upper roller is fixed vertically while the lower roller is able to slide vertically. A loading cylinder is used to move the lower cylinder vertically within the frame. The loading cylinder is mounted on a beam structure which is attached at its ends to the inner walls of the frame legs. The beam structure is shaped so that it is able to flex or pivot relative to the frame's legs so that only vertical forces are transmitted to the frame and transmission of bending moments from the beam structure to the frame structure and the foundation is substantially eliminated.

Growing community of inventors

Järvenpää, Finland

Erkki Leinonen