PREFERENTIAL DEFECT MARKING ON A WEB

• US 20090265127A1
• Filed: 04/17/2008
• Published: 10/22/2009
• Est. Priority Date: 04/17/2008
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: FLOEDER, Steven P., Skeps, Carl J., Smith, Jason P., Masterman, James A.
• Granted Patent: US 7,937,233 B2
• Time in Patent Office: Days
• US Class Current: 702/82
• CPC Class Codes: D21G 9/0045 controlling the calendering or finishing
• CPC Class Codes: D21G 9/0054 details of algorithms or programs
• CPC Class Codes: G01N 21/89 in moving material, e.g. running paper or textiles G01N21/90, G01N21/91, G01N21/94 take precedence

Abstract

A system for preferentially marking defects on a web is described. The system includes a web of material to be converted into individual sheets of a plurality of different grade levels, a database storing anomaly data of anomalies on the web, wherein an anomaly is a potential defect in at least one of the plurality of different grade levels, a marker that associates a unique mark with at least one of the grade levels, and a controller to retrieve the anomaly data from the database and to signal the marker as to where to make a mark, wherein the marker applies the mark associated with at least one of the grade levels for which the anomaly may cause a defect. The system may provide advantages, such as that a converter of various products from a single web roll may determine which regions of the web satisfy each grade level.

Claims

1. A method comprising:

obtaining a web to be converted into individual sheets of a plurality of different grade levels;

associating a unique mark with each of the different grade levels;

obtaining anomaly data that identifies positions of anomalies on the web for each of the grade levels, wherein each of the anomalies represents a physical deviation of the web that is a potential defect for at least one of the plurality of different grade levels; and

marking the position of each anomaly on the web at the position of the anomaly, wherein each anomaly is marked with each of the marks corresponding to each of the grade levels for which the anomaly is determined to be a defect.

2. The method of claim 1, wherein marking the position of each anomaly comprises:

applying at least two different application-specific defect detection algorithms to determine that the first one of the anomalies is a defect for at least two of the different plurality of grade levels; and

marking at least two different unique marks on the web at the position for the first one of the anomalies.

3. The method of claim 2, wherein the two different application-specific defect detection algorithms determine that the first one of the anomalies is a defect for the two different plurality of grade levels based on a severity of the physical deviation of the web represented by the first one of the anomalies.

4. The method of claim 3, further comprising applying a third application-specific defect detection algorithm to determine, based on the severity, that the physical deviation of the first one of the anomalies is not a defect for at least one of the plurality of grade levels.

5. The method of claim 1, further comprising:

processing image data of the web to produce the anomaly data to include a plurality of anomaly objects, each of the anomaly objects representing a distinct area of the web and defining a plurality of characteristics for the physical deviation of the web at that distinct area, and

applying a plurality of different application-specific defect detection algorithms to each of the anomaly objects to determine whether each of the anomaly objects represents a defect for each of the different grade levels.

6. The method of claim 5, wherein the characteristics defined by the anomaly objects include a length and a width of the area of the web for the physical deviation.

7. The method of claim 1, wherein marking the position of each anomaly comprises:

applying at least different two different application-specific defect detection algorithms to determine that the first one of the anomalies is a defect for less than all of the different plurality of products; and

marking less than all of the different unique marks on the web at the position for the first one of the anomalies.

8. The method of claim 1, wherein obtaining a web comprises receiving the web from a web producer.

9. The method of claim 1, wherein obtaining a web comprises manufacturing the web as a continuous web.

10. The method of claim 1, wherein obtaining anomaly data comprises receiving the anomaly data from a web producer.

11. The method of claim 1, wherein obtaining anomaly data comprises:

an optical inspection system inspecting the web as the web is produced by a manufacturing line;

an analysis computer locating a position of at least one anomaly that is a potential defect for at least one of the different products into which the web may be converted; and

recording the position of the anomaly.

12. The method of claim 11, further comprising recording each of the products for which the located anomaly is a potential defect along with the recorded position of the anomaly.

13. The method of claim 1, wherein marking the position comprises:

manufacturing the web to include a cover sheet over the web; and

marking each anomaly on the cover sheet at a position that corresponds to the position of the anomaly on the web.

14. The method of claim 1, wherein associating a unique mark comprises associating a unique geometric shape with each of the products.

15. The method of claim 1, wherein associating a unique mark comprises associating a unique color with each of the products.

16. The method of claim 1, wherein associating a unique mark comprises associating a unique number of hash marks with each of the products.

17. The method of claim 1, further comprising transferring the web and the cover sheet to a converter.

18. The method of claim 17, further comprising:

selecting products into which to convert the web in accordance with the marked anomalies; and

converting the web into the selected products.

19. A method comprising:

receiving a web to be converted into individual sheets of a plurality of different grade levels, wherein the web has marks to indicate positions of anomalies on the web, wherein the marks include a unique mark for each of the different grade levels;

separating the web into the individual sheets;

selecting, for each individual sheet, one or more of the products into which to incorporate the sheet in accordance with the marks; and

incorporating each sheet into the selected product or products.

20. The method of claim 19, wherein receiving a web comprises receiving a web covered with a cover sheet, wherein the cover sheet bears the marks to indicate positions of the anomalies on the web.

21. The method of claim 20, further comprising removing the cover sheet from the section before incorporating the sheet into the selected product or products.

22. The method of claim 19, wherein selecting comprises:

inspecting at least one mark to determine in which of the products the anomaly may cause a defect; and

selecting at least one of the products for the sheet bearing the inspected mark for which the anomaly will not cause a defect.

23. A system comprising:

a web of material to be converted into individual sheets of a plurality of different grade levels;

a database storing anomaly data of anomalies on the web, wherein an anomaly is a potential defect in at least one of the plurality of different grade levels;

a marker that associates a unique mark with at least one of the grade levels; and

a controller to retrieve the anomaly data from the database and to signal the marker as to where to make a mark,

wherein the marker applies the mark associated with at least one of the grade levels for which the anomaly may cause a defect.

24. The system of claim 23,

wherein the web comprises a cover sheet to cover the web, and

wherein the marker applies the mark to the cover sheet.

25. The system of claim 23, further comprising a plurality of controllers and a plurality of markers, wherein there is one controller for each marker, and wherein there is one marker for each of the grade levels into which the web may be converted.

26. The system of claim 23, further comprising an inspection system to inspect the web, to store the anomaly data in the database, and to determine in which of the products each anomaly may cause a defect.

27. A computer-readable medium comprising instructions for causing a programmable processor to:

retrieve web identifying information, wherein the web is to be converted into individual sheets of a plurality of different grade levels;

associate a unique mark with each of the grade levels;

obtain anomaly data that identifies positions of anomalies on the web for each of the grade levels, wherein each of the anomalies represents a physical deviation of the web that is a potential defect for at least one of the plurality of different grade levels; and

signal a marker to mark the position of each anomaly on the web at the position of the anomaly, wherein each anomaly is marked with each of the marks corresponding to each of the grade levels for which the anomaly is determined to be a defect.