Method and apparatus for controlling the manufacturing quality of a moving web
First Claim
1. A real-time method of deriving composition information regarding a moving web in a manufacturing environment, said method comprising steps of:
- (a) providing a photodetector assembly having a plurality of photodetectors at respective detection locations across the transverse direction of said moving web;
(b) illuminating said moving web so as to provide electromagnetic energy at each of said photodetectors;
(c) measuring electromagnetic energy at each of said detection locations;
(d) deriving said composition information for each of said detection locations based on absorbance of said electromagnetic energy thereat; and
(e) controlling application of a predetermined add-on component to said moving web based on said composition information, said add-on component contributing selected characteristics to the web.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for detecting the composition of a moving web product on a real-time basis during the manufacturing process. Spectrometric monitoring equipment operates to derive information regarding physical and/or chemical properties of the web at multiple locations in the web'"'"'s cross direction. Data from a plurality of spectral regions can be combined to produce a vector containing accurate information regarding the web'"'"'s composition. This information is derived using multivariate mathematical techniques to yield a spatial data matrix for each component of interest. Composition information contained in the spatial data matrix can be reprojected as a “virtual composition map,” or compared against ideal profiles stored in a computer memory.
82 Citations
33 Claims
-
1. A real-time method of deriving composition information regarding a moving web in a manufacturing environment, said method comprising steps of:
-
(a) providing a photodetector assembly having a plurality of photodetectors at respective detection locations across the transverse direction of said moving web;
(b) illuminating said moving web so as to provide electromagnetic energy at each of said photodetectors;
(c) measuring electromagnetic energy at each of said detection locations;
(d) deriving said composition information for each of said detection locations based on absorbance of said electromagnetic energy thereat; and
(e) controlling application of a predetermined add-on component to said moving web based on said composition information, said add-on component contributing selected characteristics to the web. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. An apparatus for deriving composition information regarding at least one predetermined component of a moving web, said apparatus comprising:
-
a plurality of radiation sources adapted to illuminate said moving web with electromagnetic energy in at least two predetermined frequency bands;
a photodetector assembly having a plurality of photodetectors spaced apart from said moving web for detecting levels of said electromagnetic energy in respective of said frequency bands, said photodetector assembly being operative to detect levels of said electromagnetic energy at multiple detection locations across the transverse direction of said moving web; and
processor means in electrical communication with said photodetector assembly, said processor means operative to derive said composition information for each of said detection locations based on absorbance of said electromagnetic energy thereat. - View Dependent Claims (15, 16, 17, 18, 19, 20)
-
-
21. A real-time method of deriving composition information regarding at least one predetermined component added to a moving web of tissue paper in a manufacturing environment, said method comprising steps of:
-
(a) illuminating said moving web with electromagnetic energy in at least two predetermined frequency bands;
(b) measuring said electromagnetic energy as diffused by said moving web at each of a plurality of detection locations across a transverse direction of said moving web;
(c) deriving said composition information for each of said detection locations based on absorbance of said electromagnetic energy thereat; and
(d) controlling application of said predetermined component to said moving web based on said composition information. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30)
-
-
31. A real-time method of deriving composition information regarding at least one predetermined component added to a moving web, said method comprising steps of:
-
(a) illuminating said moving web with electromagnetic energy;
(b) at each of a plurality of detection locations across a transverse direction of said moving web, measuring said electromagnetic energy in a plurality of frequency bands falling within a frequency range of 0.2-200 microns;
(c) combining spectral information at each of said frequency bands into a supervector; and
(d) processing said supervector using multivariate mathematical techniques to produce a spatial data matrix of said composition information correlated to said detection locations. - View Dependent Claims (32, 33)
-
Specification