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AssigneeStora Enso Aktiebolag
InventorsRaija Badenlid, Staffan Andersson, Eva-Lena Stromberg, Jenny Bergstrom
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Method for predicting properties of a cellulose-fibre-based product, a suspension of cellulose fibre being analysed during manufacture of the product by means of spectroscopic measurements (13, 15) in a selected spectrum in the wavelength range 200-25000 nm. According to the invention, each sample quantity is diluted (3, 4) prior to said analysis, following which one partial flow (6) is dewatered and dried (8) and used for said spectroscopic measurements (13, 15), while a second partial flow (5) of the diluted sample quantity is used for analysis (7, 14) of physical fibre data, by means of image analysis, each sample quantity analysed generating at least 100 data points from the spectroscopic measurement, and at least 50 data points with regard to said physical fibre data, in the form of one or more physical fibre property distributions, which data points are combined in multivariate data processing (16), for said prediction.
Method for predicting properties of a product that consists of cellulose-fibre-based pulp, paper or paperboard, a suspension of cellulose fibre being analysed during manufacture of the product by means of spectroscopic measurements (13, 15) of a sample quantity of said suspension in a selected spectrum in the wavelength range 200-25000 nm, characterized in that each sample quantity, prior to said analysis, is diluted (3, 4), following which one partial flow (6) is dewatered and dried (8) and used for said spectroscopic measurements (13, 15), while a second partial flow (5) of the diluted sample quantity is used for analysis (7, 14) of physical fibre data, by means of image analysis, each sample quantity analysed generating at least 100 data points from the spectroscopic measurement distributed in the selected spectrum, and at least 50 data points with regard to said physical fibre data, in the form of one or more physical fibre property distributions with regard to at least one physical property in the group that consists of fibre length, fibre width and fibre shape, which data points are combined in multivariate data processing (16), for said prediction, on the basis of calibrations previously executed that were carried out on samples with known product attributes.
Method according to any of the above claims, characterized in that product attributes predicted by means of the method for an individual base paper bale or roll produced in pulp manufacture are compared with desired product attributes for a number of different paper- or paperboard-producing customers, this comparison being taken as a basis for the choice of customer to whom the bale or roll is then delivered.
Method according to any of the above claims, characterized in that said spectrum consists of the wavelength range 400-2500 nm, preferably 780-2500 nm, in which spectrum at least 100 data points, preferably at least 300 data points, even more preferredly at least 500 data points and most preferredly at least 800 data points are generated for each sample quantity, which data points consist of mean values of a number of sweeps in the spectrum, preferably at least 10 sweeps.
Method according to any of the above claims, characterized in that said physical fibre data are obtained by means of a CCD camera, at least 50 data points, preferably at least 100 data points and even more preferredly at least 150 data points being generated for each sample quantity, which data points consist of distribution data with regard to at least two, preferably all physical attributes in the group consisting of fibre length, fibre width and fibre shape, and preferably also of fibre weight per metre and fibre flexibility.
Method according to any of the above claims, characterized in that said dilution (3, 4) is carried out during agitation to a concentration of less than 0.5%, preferably less than 0.1%, and that said dewatering and drying (8) is carried out to at least 50% dry content, preferably at least 70% dry content.
Dependencies are inferred from the claim text.