Nanometer Chitosan Modified Lyocell Fiber Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for producing Lyocell fibers with antifungal, antibacterial, and deodorant capabilities face limitations due to restrictive ranges in degree of polymerization and chitosan content, leading to high processing costs and inadequate persistence of these properties in mass production, along with inefficient solvent recovery processes.
Innovation Solution
A method involving the modification and reduction of chitosan to a nanometer scale, blending it with wood pulp and NMMO solvent, and using a dry-jet wet spinning process to produce cellulose fibers with enhanced antifungal, antibacterial, and deodorant properties, while also optimizing solvent recovery through simplified bleaching, filtration, condensation, and refinement procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to produce Lyocell fibers with antifungal, antibacterial, and deodorant capabilities, then the fiber properties are achieved, but the processing cost is high and the persistence of these properties is inadequate
Solution Approach 1:
The patent changes the molecular weight parameter of chitosan from conventional high molecular weight to low molecular weight (5-50 kDa), and adjusts the chitosan content parameter to 0.1-5% range. These parameter changes enable the fiber to maintain antifungal, antibacterial, and deodorant properties with better persistence while reducing processing costs through more efficient incorporation of the functional material
Solution Approach 2:
The patent creates a composite material system by combining Lyocell fiber (regenerated cellulose) with low molecular weight chitosan in a controlled composition. This composite structure integrates the mechanical properties of Lyocell with the bioactive properties of chitosan, achieving persistent antifungal, antibacterial, and deodorant effects while maintaining manufacturing feasibility
2Manufacturing precision
If the range of degree of polymerization and chitosan content is restricted, then the fiber quality is maintained, but the processing cost increases
Solution Approach 1:
The patent expands the acceptable range of degree of polymerization for cellulose and optimizes the chitosan content range to 0.1-5%. These parameter adjustments broaden the manufacturing window, allowing greater flexibility in raw material selection and process conditions while maintaining fiber quality standards and reducing processing costs through less stringent control requirements
3Loss of substance
If solvent recovery process is complex, then the recovery rate is high, but the processing time and cost increase
Solution Approach 1:
The patent extracts and isolates NMMO solvent from the fiber processing stream for separate recovery and reuse. By separating the solvent recovery process from the main fiber production line, the system achieves high recovery rates (99%+) without significantly impacting fiber production time, as the solvent can be recovered and prepared for reuse in parallel operations
Solution Approach 2:
The patent implements a solvent recovery system that captures NMMO from the processing waste stream, purifies it, and returns it to the production process. This closed-loop approach minimizes solvent loss while the efficient design of the recovery system ensures that the time and cost penalties are minimized through automated processing and continuous operation
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 expands the range of applicable degree of polymerization and chitosan content, reducing processing costs and maintaining effective antifungal, antibacterial, and deodorant capabilities, while achieving a high solvent recovery rate, thus enhancing the economic and environmental sustainability of the process.
Implementation Method 1
modify and reduce the properties of the natural chitosan of high polymer to nanometer scale
Implementation Method 2
mix it with wood pulp and non-toxic NMMO solvent to yield dope
Implementation Method 3
coordinate the improved Lyocell fiber process to produce natural cellulose fiber
Implementation Method 4
the recovery rate of the NMMO solvent is over 99.5% for reuse
Implementation Method 5
optimizing solvent recovery through simplified bleaching, filtration, condensation, and refinement procedures
Data Source
AI summary
The present invention provides a processing method of the natural cellulose fiber with feature for enhancing the capability of antifungi, antibacteria and deodorization. The procedure is that firstly modify and reduce the properties of the natural chitosan of high polymer material to nanometer scale; secondly dunk the chitosan into the syrup-like mixture of wood pulp and NMMO solvent to yield quasi-dope; thirdly dehydrate the quasi-dope of paste mixture to form the mud-like dope; fourthly spin the dope by dryjet wet spinning method; fifthly regenerate the filament in coagulation bath, water rinse and dry; finally water rinse, dry, apply the lubricant to finish. The water soluble chitosan, which has been treated by property modification and reduced to nanometer scale, can effectively and completely solve in the cellulose of low DP to offer wider extent of selection in the DP and better flexibility of adding percentage in content of modified chitosan.