Metso Paper Inc.

Valmet Technologies Oy

Jari Paanasalo

Pauli Koutonen

Arto Leskinen

Kenneth Åkerlund

Mikko Veijalainen

A method of operating an off-line finishing device for fiber webs, in particular an off-line slitter-winder for winding fiber webs, wherein in operating the off-line device the running speed is automatically optimized to minimize cost of web breaks. The method considers the costs associated with a web break during unwinding in addition to the cost benefit of maximizing web unwind speed so as to maximize machine utilization. The method determines an optimal web break stopping time in a web break situation and how often a web break is predicted. Automatic optimization incorporates limitations including the maximum rotation speed of the parent roll, the maximum speed of the fiber web being unwound, the maximum positive torque which can be applied to the parent roll to accelerate the parent roll to a rotation rate which produces a desired web speed, and maximum braking torque.

Method of operating an off-line finishing device for fiber webs, in particular an off-line slitter-winder for winding fiber webs

This invention relates to a method of controlling the operation of a winder in which method while forming at least one fiber web roll the fiber web is brought on the web roll via a nip formed by a first support drum and the web roll, which first support drum is driven by a first drive assembly () applying controllable torque to the drum and the winding force is applied to the web roll by a second drive assembly (). In the method the second drive assembly () is controlled based on the indicative speed difference of the second drive assembly () and setting a friction coefficient for determination of maximum winding force.

Method of controlling operation of a winder for a fiber web

The stopping of a winder is controlled such that winding is stopped when a desired length of a web has been wound on a roll being formed/unwound from a roll being formed or when the size of the diameter of the roll is desired. An estimated stopping length is calculated based on speed, acceleration and a desired end speed.

Method for controlling winder

The slitters of a slitter-winder in a paper or board machine are placed in position in slitting to slit component webs to the desired width. The slitters are moved to a new slitting position as a normal movement when the slitter-winder has stopped after slitting according to the preceding slitter setting. In positioning the slitters, at least one slitter not in use in the slitter-winder is moved before the normal movement as an advance movement to a new slitting position and/or to a waiting position for the next slitting position while the other slitters are slitting the web.

Method for positioning the slitters of a slitter-winder in a paper or board machine

A method for determining roll density in connection with a web reel. A known relation between the length (l), diameter (D), basis weight (b) and density (&#x3c1;) of the wound roll, formula (1) is used. Distortions caused in the measurement results by noise and other disturbances are eliminated by using a recursive time variant least squares method in the processing of the measurement results l=&#x3c0;&#x3c1;(D&#x2212;D)/4b.

Method for determination of roll density

The invention concerns a method in winding of a web in a centre-drive winder, wherein the roll that is being formed is loaded and/or supported by means of a rider roll unit ( ) whose position can be varied and which consists of at least two rolls ( ). In the method, the force that is applied by the rider roll unit ( ) to the roll face in the radial direction and/or the distribution of said force between the rolls ( ) in the rider roll unit ( ) is/are measured by means of a detector of detectors ( ) directly connected with the winding head of the rider roll unit ( ). The nip force of the rolls ( ) in the rider roll unit ( ) and/or the distribution of said nip force is/are regulated on the basis of the measurement signal given by the detectors.

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Järvenpää, Finland

Jari Paanasalo