Process for detecting and correcting a fiber orientation cross direction profile change

A process for detecting a change in fiber orientation cross-direction profile of a paper or cardboard web in a manufacturing process on a paper or cardboard manufacturing machine, comprising:

• repeatedly determining a basis weight cross-direction profile of the web;
• determining change in the basis weight cross-direction profile;
• determining wavelengths of the change in the basis weight cross-direction profile;
• and,
• comparing the wavelengths of the change in the basis weight cross-direction profile to a predetermined value raster for determining if the change correspond to a change in the fiber orientation.

A process for detecting a change in fiber cross-direction profile of a paper or cardboard web in a manufacturing process on a paper or cardboard web manufacturing machine, comprising:

• determining a chronological course of a basis weight of the web in at least one position of the web with respect to a width of the machine;
• determining a chronological change in the basis weight in the at least one position;
• determining one of a change speed and a relative change speed of the basis weight in the at least one position;
• comparing said one of the change speed and the relative change speed to a predetermined value raster for determining if said one of the change speed and the relative change speed corresponds to a change in the fiber orientation cross-direction.

A process for detecting a change in fiber orientation cross-direction profile in a paper web, comprising:

• measuring a basis weight cross-direction profile and a basis weight longitudinal direction profile of the paper web by using at least two sensors;
• determining existence of deformation of a headbox in a machine manufacturing the paper web by determining a wavelength of a change in the basis weight cross-direction profile;
• determining a course of the basis weight longitudinal direction profile at a position of a maximum change in the basis weight cross-direction profile;
• and,
• determining the existence of deformation of the headbox and influence of the deformation on the fiber orientation cross-direction profile from one of a characteristic chronological course of the basis weight and change of speed of the web.

A process for detecting a change in fiber orientation cross-direction profile of a paper or cardboard web in a manufacturing process on a paper or cardboard manufacturing machine, comprising:

• determining one of the basis weight cross-direction profile of the web and a cross-direction profile of a correlated measured quantity by using at least one sensor;
• determining the change in said one of the cross-direction profile of the basis weight and the correlated measured quantity by using at least one determining device;
• determining wavelengths of the changes by at least one wavelength measuring device;
• comparing the wavelengths of the cross-direction profile of the changes to a predetermined value raster for determining if the change corresponds to a change in the fiber orientation cross-direction profile by using a comparing element;
• and,
• indicating the change in the fiber orientation cross-direction profile in an output unit.

A device for detecting a change in a fiber orientation cross-direction profile in at least one position in a paper or cardboard web in the manufacturing process on a paper or cardboard manufacturing machine, comprising:

• at least one sensor having an evaluation unit for determining a chronological course of a basis weight in a traveling direction of the web in at least one position with regard to a width of the machine;
• at least one determining unit for determining at least one of a change speed and a relative change speed of the basis weight in said at least one position with respect to the width of the machine;
• at least one comparing unit for comparing the change speed to a predetermined value raster for determining if the change speed can correspond to a change in the fiber orientation cross-direction profile;
• and,
• an output device for indicating a change in the fiber orientation cross-direction profile.

A device for detecting a change in a fiber orientation cross-direction profile of a paper or cardboard web in a manufacturing process on a paper or cardboard manufacturing machine, comprising:

• at least one determining unit for determining a chronological course of a basis weight in a longitudinal direction of the web in at least one position with respect to a width of the machine;
• at least one determining element for determining one of a change speed and a relative change speed of the basis weight in said at least one position with respect to the width of the machine;
• at least one comparing unit for comparing the change speed to a predetermined value raster;
• a determining unit for determining if the change speed of the basis weight corresponds to a change in the fiber orientation cross-direction profile;
• and,
• an output device for indicating the change in the fiber orientation cross-direction profile.

A device for detecting a change in a giver orientation cross-direction profile of a paper or cardboard web in a manufacturing process on a paper or cardboard manufacturing machine, comprising:

• at least two sensors and at least one evaluation unit for determining a basis weight cross-direction profile and a basis weight longitudinal direction profile of the paper web;
• at least one wavelength determining unit for determining a wavelength indicative of a change in the basis weight cross-direction profile and a deformation of a headbox of the machine;
• at least one course determining unit for determining a course of the basis weight longitudinal direction profile at the position of a maximum change in the basis weight cross-direction profile and for verifying a deformation of the headbox and an change in the fiber orientation cross-direction profile being determined from a characteristic chronological course of one of the basis weight and the change speed of the basis weight;
• and,
• an output unit for indicating the change in the fiber orientation cross-direction profile.