Patent ID: 7153391

Claim:
Method for predicting properties of a product that consists of cellulose-fibre-based pulp, paper or paperboard, wherein a suspension of cellulose fibre is subjected to analysis during manufacture of the product by spectroscopic measurements of a sample quantity of said suspension in a selected spectrum in the wavelength range 200–25000 nm, said method comprising: diluting each sample quantity prior to said analysis; dewatering and drying a first partial flow; subjecting said first partial flow to spectroscopic measurements in a selected spectrum in the wavelength range 200–25000 nm; analyzing a second partial flow of the diluted sample quantity for physical fibre data, by means of image analysis; each sample quantity analysed generating at least 100 data points from the spectroscopic measurements distributed in said 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 consisting of fibre length, fibre width and fibre shape, which total of at least 150 data points are combined in multivariate data processing, for prediction of physical properties of said product, on the basis of calibrations previously executed that were carried out on samples with known physical properties.