IR Starch Measurement Cellulose Surface Sizing

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Solution Overview

Problem

Conventional spectroscopy methods fail to accurately determine the amount of starch used in surface sizing of cellulose products due to overlapping absorption peaks with cellulose, and existing methods like dry weight difference measurement are prone to significant errors and require ionizing radiation.

Innovation Solution

A transmission method using IR spectroscopy measures absorption values before and after starch addition, calculating the starch amount from the difference in absorption values at the cellulose and starch common wavelength range, eliminating the need for separate basis weight measurement and reducing measurement uncertainty.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional spectroscopy methods are used to measure starch absorption, then measurement can be performed, but the absorption peak of starch overlaps with cellulose absorption peak making accurate determination impossible

Engineering Contradiction:
Improvestarch amount determination accuracyVSAvoidabsorption peak overlap
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The measurement process is segmented into two distinct stages: first measuring the absorption value of cellulose before starch addition, then measuring the combined absorption value of cellulose and starch after addition. By separating the measurement into these segments and calculating the difference, the patent isolates the starch contribution from the overlapping absorption signals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs a preliminary measurement of the cellulose absorption value before starch is added to the surface size. This preliminary action establishes a baseline that is then subtracted from the post-addition measurement, allowing accurate determination of starch amount despite the overlapping absorption peaks.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If dry weight difference measurement is used to determine starch amount, then measurement can be performed, but significant measurement errors occur and ionizing radiation is required

Engineering Contradiction:
Improvestarch amount determination accuracyVSAvoidionizing radiation exposure
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical/physical method of dry weight difference measurement (which requires ionizing radiation for basis weight measurement) with an optical spectroscopy method. By using IR absorption measurements and calculating the difference, the patent achieves accurate starch determination without requiring basis weight measurement via ionizing radiation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from mass/density (requiring basis weight measurement) to optical absorption properties. By measuring IR absorption values before and after starch addition and calculating the difference, the patent determines starch amount without needing to measure basis weight with ionizing radiation.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly improves measuring accuracy and reduces the need for ionizing radiation, providing precise starch quantification with improved precision and reduced measurement errors.

Implementation Method 1

absorption of radiation, i.e. radiation absorbed by the material, at several wavelengths of infrared radiation. The absorbance of infrared radiation is proportional to the concentration of the absorbing substance in the sample

Methodology Applied
Scientific EffectAbsorption of infrared radiation: Absorption (EM radiation)

Data Source

PatentEP2326938B1Determining the amount of starch
Publication Date: 2021.01.20 VALMET AUTOMATION OY
  • EP2326938B1 patent drawingFigure 1~3

AI summary

The invention relates to a method and arrangement for determining the amount of starch used in surface-sizing a cellulose product. In the solution according to the invention, the amount of starch is determined with a transmission method utilizing IR spectroscopy by using absorption wavelengths of cellulose. Absorption values are measured before adding a coating and after it, whereby the amount of starch is determined from the difference between these absorption values.