Method for determining chemical pulp kappa number with visible-near infrared spectrometry

A chemical pulp and near-infrared technology, which is applied in the fields of automatic pulping process, cellulose pulp post-treatment, color/spectral characteristic measurement, etc.

Active Publication Date: 2008-02-27
FPINNOVATIONS INC
View PDF5 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the prior art, no method is presented that can determine lignin content with sufficient precision and detail to give useful measurements for production process and / or quality control

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for determining chemical pulp kappa number with visible-near infrared spectrometry
  • Method for determining chemical pulp kappa number with visible-near infrared spectrometry
  • Method for determining chemical pulp kappa number with visible-near infrared spectrometry

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0051] Pulp fiber samples were first squeezed by hand to remove excess water and placed on a sample tray. During data collection, rotate the tray to provide better averaging and improve statistical significance. Figure 3 shows the results obtained for hemlock pulp, which was sampled from the final natural stock washer and all the individual washers of the bleach plant. A local least squares multivariate calibration was used, resulting in a calibration using a combination of the preferred spectral regions 350nm to 750nm and 1100nm to 2400nm. Generating the plot with 6 factors gives an R of 0.9999 2 model. Note that there are 10 data points at each concentration level, demonstrating the extremely good reproducibility of the invention. The estimated root mean square standard error (RMSEP) was 0.2 kappa with a reproducibility of 0.05 kappa. Furthermore, these results also show that the present invention is capable of measuring the residual lignin content of chemical pulps full...

example 2

[0053] Figure 4 plots the results produced with the same data set described above, but with the selected calibration region spanning only the NIR range of 1100nm to 2500nm, as indicated in the prior art. The results proved to be poor data with an expected error of ±2 kappa, much higher than the results obtained in the present invention.

example 3

[0055] Figure 5 plots the results produced with the same data set above, but calibrated at another spectral range taught by the prior art, namely 850nm to 1050nm. As shown, the results obtained with the prior art teaching, again the teaching is not suitable for use in the present invention, as the expected error is on the order of ±4 kappa.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
flow consistencyaaaaaaaaaa
Login to view more

Abstract

A method for the determination of a cellulosic-fibre property, namely, residual lignin content or Kappa number of chemical pulp, with the aid of a spectroscopic technique obtained over a range covering the visible and the near-infrared regions of the electromagnetic spectrum, comprising exposing the wet fibres to a light source covering a range in the visible region of 350 nm to 750 nm and a range in the near-infrared of 1100 nm to 2400 nm, reflecting light from the wet fibres, establishing a spectrum, comparing the spectrum with a known spectrum of the property and evaluating the comparison; the method has particular utility in a pulp manufacture line; an apparatus is described for carrying out the method.

Description

technical field [0001] The invention relates to a novel method for measuring fiber properties, in particular to a method for measuring the residual lignin content of chemical pulp in visible and near-infrared spectral regions by means of a fast scanning spectrometer. Background technique [0002] Accurate online measurement of chemical pulp Kappa number from rapidly changing furnish remains an unsolved problem in chemical pulp production. Mills using residual sawmill chips from various locations and those producing specific grades are particularly affected by the variability in chip quality from different suppliers. This problem is becoming even more prevalent now that pulp and paper mills have to source wood chips geographically away from their manufacturing facilities due to a shortage of available market wood chips. Often, pulp produced at grade change, or from a mixture of chip species that lacks character, because each chip species requires different cooking, a high pr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01N21/35G01N33/46D21C7/12D21C9/02
CPCG01N33/343D21C9/1036G01N21/3563D21C9/1052G01N2021/3155G01N21/359D21C3/228
Inventor 特纳恩·P·特伦格斯蒂芬·P·A·贝兹德尼·F·勒克莱尔
Owner FPINNOVATIONS INC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap