Biocide Dosing Control for Cellulolytic Activity in Fiber Suspensions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In paper and board mills, high microbial growth leads to issues like odor, decreased machine productivity, and poor quality paper products due to uncontrolled cellulolytic activity in aqueous cellulose fiber suspensions, particularly with recycled fibers, which affects the strength and quality of the final fibrous web products.
Innovation Solution
Monitoring and controlling cellulolytic activity in aqueous cellulose fiber suspensions or process water using biocides to maintain optimal levels, thereby protecting cellulose fibers and ensuring consistent product quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If biocides are added to control microbial growth in recycled fiber suspensions, then cellulolytic activity is reduced and fiber strength is preserved, but the complexity of the production process increases due to monitoring and controlled addition requirements
Solution Approach 1:
The patent implements a feedback control system where cellulolytic activity is monitored in real-time during the papermaking process, and biocide addition is adjusted based on measured activity levels. This closed-loop approach maintains fiber strength by responding to actual microbial activity rather than using fixed dosing schedules, resolving the contradiction between effective strength protection and process complexity through intelligent automation.
Solution Approach 2:
The system enables self-regulation of microbial activity control by automatically measuring cellulolytic activity and triggering biocide addition only when activity exceeds predetermined thresholds. This self-service mechanism reduces the need for continuous manual intervention and complex centralized control, allowing the process to self-adjust while maintaining fiber strength protection.
2Strength
If biocides are continuously added to prevent cellulolytic degradation, then fiber strength is maintained, but the cost and environmental impact of biocide usage increases
Solution Approach 1:
The patent applies partial action by adding biocides only when cellulolytic activity exceeds predetermined thresholds rather than continuous full-dose application. The system measures actual microbial activity and triggers biocide addition selectively, using exactly the amount needed to control degradation when present, thereby maintaining fiber strength while minimizing biocide consumption and environmental impact.
Solution Approach 2:
The system dynamically adjusts biocide addition based on changes in cellulolytic activity parameters. By monitoring activity levels and triggering treatment only when parameters indicate problematic degradation, the system optimizes biocide usage quantity while maintaining fiber strength, avoiding both under-treatment and excessive chemical application.
3Reliability
If high rates of fiber recycling are used to improve sustainability, then environmental performance improves, but cellulolytic microbial growth increases leading to decreased product quality
Solution Approach 1:
The patent converts the harmful effect of microbial activity into a beneficial monitoring signal. By measuring cellulolytic activity as an indicator of microbial presence and degradation risk, the system triggers selective biocide application that protects fiber strength in recycled suspensions. This approach enables high recycling rates to be sustained while maintaining product quality, as the system actively manages rather than passively accepts microbial challenges.
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 effectively reduces cellulolytic activity to desired levels, enhancing the strength and quality of fibrous web products, such as paper and board, by optimizing biocide usage and allowing for higher recycling rates of fiber materials without compromising product properties.
Implementation Method 1
controlling cellulolytic activity in an aqueous cellulose fiber suspension or process water for a production method of a fibrous web comprising at least a share of recycled cellulose fibers
Data Source
AI summary
The present invention relates to the fields of fibers and uses thereof such as for producing fiber webs, such as paper, board or tissue. Specifically, the invention relates to a method of monitoring and controlling cellulolytic activity in an aqueous cellulose fiber suspension or process water for a production method of a fibrous web containing cellulose fibers. Also, the present invention relates to a method of manufacturing a fibrous web, such as a paper, board, tissue or the like, and use of a biocide for controlling cellulolytic activity in an aqueous cellulose fiber suspension or in process water e.g. for a production method of a fibrous web containing cellulose fibers. Still, the present invention relates to a fibrous web, such as a paper, board, tissue or the like, an aqueous cellulose fiber suspension or process water for a production method of a fibrous web containing cellulose fibers, and a system for controlling cellulolytic activity in an aqueous fiber suspension or in process water.