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

Process and a device for detecting a change in the fiber orientation cross-direction profile of a paper or cardboard web in the manufacturing process on a paper or cardboard machine. It is recognized that a change in the fiber orientation cross-direction profile in the web is inferred or determined by way of a characteristic change in the basis weight cross-direction profile or at least one measurement quantity that correlates to it, and/or by way of a characteristic change in the basis weight in the travel direction of the web or at least one measurement quantity that correlates to it. The device includes an arrangement for detecting a change in the basis weight cross-direction profile and/or a characteristic chronological course of the change in the basis weight, which is characteristic for a change in the fiber orientation.

If you were to search for Device for detecting and correcting a fiber orientation cross direction profile change using relaxed search criteria, these patents would come up:

What is claimed is:

1. 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 paperor 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.

2. A device 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:

at least one determining unit comprising at least one sensor for determining a chronological course of a basis weight in a travel 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-directional profile.

3. A device for detecting a change in a given 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 travel 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 travel 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 a changein 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.

4. The device of claim 1, including:

an arithmetic unit including one of an evaluation program and an evaluation sub-program.

5. The device of claim 2, wherein said at least one sensor comprises at least two sensors, and said device further comprises:

a controlled motion unit for controlling motion of the at least two sensors in a direction lateral to the travel direction of the web.

6. The device of claim 2, wherein a first sensor is moveable laterally to a direction of the machine and another sensor is stationary with respect to the machine.

7. The device of claim 2, wherein at least one of the sensors is provided in a region of a stock suspension stream emanating from a headbox supplying a suspension to the machine.

8. The device of claim 2, wherein at least one of the sensors is provided in a region of a former portion of the paper or cardboard web manufacturing machine.

9. The device of claim 2, wherein at least one of the sensors is provided in a region of a press section of the paper or cardboard web manufacturing machine.

10. The device of claim 2, wherein at least one of the sensors is provided in a region of a drying section of the paper or cardboard web manufacturing machine.

11. The device of claim 2, wherein at least one of the sensors is provided in a region between a former and a press section of the paper or cardboard web manufacturing machine.

12. The device of claim 2, wherein at least one of the sensors is provided in a region between a press section and a drying section of the paper or cardboard web manufacturing machine.

13. The device of claim 2, wherein at least one of the sensors measures at least one of stock density of a suspension delivered from a headbox of the machine, absorption of radioactive radiation, light, ultrasound, stream density of thesuspension and stream speed of the suspension.