Method for producing a roll for a paper/boardmaking machine
AssigneeMetso Paper, Inc.
InventorsEero Savolainen, Jorma Snellman
Life of this patent
Estimating the term…
Abstract
A roll for a paper or board machine is produced by forming a tubular roll blank by bending out of a planar sheet or by means of centrifugal casting. The roll blank is first coated with a material having a modulus of elasticity and a density lower than those of steel and the coated roll blank is turned on a lathe to a desired shape and to a desired surface quality.
Claims9
A method for producing a roll for a paper or board machine, in which method a tubular roll blank is made by bending out of a planar sheet or by means of centrifugal casting,
- wherein wall thickness of the roll blank is measured during rotation of the roll blank in order to determine the shape of the outer surface, differences in stiffness of the tubular roll blank in planes passing through an axis defined by the tubular roll blank are calculated, and a shape required for balancing stiffness is determined and the shape is corrected with respect to stiffness to minimize differences in stiffness without turning the tubular roll blank,
- wherein the roll blank is then coated with a material that has a modulus of elasticity and a density lower than those of steel, and that the coated roll blank is turned on a lathe to a desired shape, by removing only the material that has an elasticity and a density lower than those of steel and the coated roll blank is turned on a lathe to a desired surface quality, whereby errors in shape of the tubular roll blank are passed to the coating as thickness variation.
A method for producing a roll for a paper machine comprising steps of:
- making a tubular roll blank by bending a planar sheet or by centrifugal casting, the roll blank having an out-of-roundness of a particular amount;
- measuring variation in wall thickness of the body shell causing differences in stiffness and compensating for the differences in stiffness by correcting the shape of the roll blank without turning on a lathe;
- applying a coating to the roll blank with the out-of-roundness of said particular amount, after correcting the shape of the roll blank without turning on a lathe, the coating being a material that has a modulus of elasticity and a density lower than those of steel;
- and
- after coating the roll blank, turning the coated roll blank on a lathe to a desired shape and to a desired surface quality, wherein only the coating is removed in the turning, wherein the out-of-roundness of the roll blank is overcome by variations in thickness of the coating.
A method for producing a roll used in a paper or board machine, comprising the steps of
- bending a planar sheet of steel to form a roll shell, having a longitudinal seam;
- welding the longitudinal seam of the roll shell to form a tubular roll blank which defines an axis and having an outer cylindrical surface;
- measuring the thickness of the tubular roll blank during rotation of the tubular roll blank;
- correcting the shape of the tubular roll blank, without turning on a lathe the tubular roll blank, such that the variations in stiffness of the tubular roll blank in planes passing through the defined axis is minimized;
- coating the outer cylindrical surface of the tubular roll blank with a coating material that has a modulus of elasticity which is considerably lower than that of steel and a density which is considerably lower than that of steel, to form a coated tubular roll blank;
- turning the coated tubular roll blank with coated outer cylindrical surface, so only said coating material is removed, producing a selected shape, and a selected surface quality, wherein the turning process produces variation in the thickness only of the coating material and not in the tubular roll blank;
- and
- using the turned coated tubular roll blank in a paper or board machine.
Dependencies are inferred from the claim text.