Phosphorylated Cellulose Pulp Bleaching Process
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cellulose fibers with phosphoric acid groups often have insufficient whiteness and are prone to coloration, making it challenging to produce pulp with high whiteness and low yellowness, especially when bleaching is performed after phosphorylation, which can damage the fibers and affect their physical properties.
Innovation Solution
Optimizing the bleaching process for phosphorylated cellulose fibers by introducing a bleaching step after phosphorylation, using suitable bleaching agents and conditions to maintain high levels of phosphoric acid groups and polymerization degree, while suppressing coloration and damage, resulting in a pulp with high whiteness and low yellowness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a bleaching step is performed after phosphorylation to improve whiteness, then the whiteness of cellulose fibers is improved, but the fiber damage and loss of physical properties worsen
Solution Approach 1:
The patent applies preliminary action by performing the phosphorylation treatment before the bleaching step. By introducing phosphoric acid groups into the cellulose fibers first, the fibers gain resistance to subsequent bleaching damage. The phosphorylated fibers then undergo bleaching with reduced harm, maintaining both whiteness improvement and physical property preservation.
2Adaptability or versatility
If the amount of phosphoric acid groups is increased to improve fiber properties, then the functional properties of cellulose fibers are improved, but the whiteness and coloration resistance worsen
Solution Approach 1:
The patent applies parameter changes by optimizing the phosphorylation conditions to achieve a specific range of phosphoric acid group content (0.3-2.0 mmol/g). By controlling this parameter within the optimal range and combining it with subsequent bleaching treatment, the patent achieves both high functional properties (adequate phosphoric acid group content) and high whiteness (through bleaching removal of colored byproducts).
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
The optimized bleaching process enables the production of cellulose fibers with high whiteness and low yellowness, maintaining desired physical properties and allowing for effective fibrillation, producing a transparent and high-viscosity slurry.
Implementation Method 1
by optimizing a bleaching process in a step of producing phosphorylated cellulose fibers, the whiteness of a pulp comprising cellulose fibers can be enhanced
Data Source
AI summary
It is an object of the present invention to optimize a bleaching process in a step of producing phosphorylated cellulose fibers. The present invention relates to a pulp comprising cellulose fibers having 0.5 mmol/g or more of phosphoric acid groups or phosphoric acid group-derived substituents, wherein when the pulp is processed into a sheet and four sheets are laminated on one another, the ISO whiteness of the laminate is 82% or more. Moreover, when the pulp of the present invention is processed into a sheet and four sheets are then laminated on one another, the b* value of the obtained laminate according to the L*a*b* color system is 5.5 or less.