Method of quantifying performance chemicals in pulp and paper

US5680320A · kind A · utility

Assignee

• Eka Nobel AB · SE

Inventors

• Ulla Helmer · Solna, SE
• Lars Renberg · Västerhaninge, SE
• Ralf Olsson · Stockholm, SE

Key dates

• Filing date: May 18, 1995
• Grant date: Oct 21, 1997
• Expiry date: May 18, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N33/343
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method is provided for quantifying the amounts of performance chemicals selected from the group consisting of wet strength agents, starches and retention agents, hydrophobic agents and debonding agents, reacted or retained with the cellulose fibers in fluff pulp or paper. The method comprises (I) developing a calibration model by (I.a) registering absorption, reflectance or emission spectral raw data of reference samples of paper or pulp containing known amounts of the performance chemicals to develop a learning set; (I.b) processing the spectral raw data from the registered spectra to reduce noise and adjust for drift and diffuse light scatter; (I.c) performing a data analysis on the learning set in which the processed spectral data of the reference samples are transferred into latent variables based on principal component analysis, and applying chemometric techniques on the latent variables in order to find the mathematical expression of the calibration model; and (II) registering absorption, reflectance or emission spectral raw data of a sample of fluff paper or pulp containing unknown amounts of chemicals, processing the spectral raw data as according to (I.b); transferring t…