Cellulose Fiber Formation Using Ionic Liquid Solvation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cellulose fiber production processes, such as viscose and cuprammonium rayon, require chemical derivatization or complexation, leading to high costs and environmental concerns due to the use of hazardous chemicals and complex regeneration processes, while existing lyocell processes face issues with solvent degradation and expensive high-alpha pulps.
Innovation Solution
A method involving the dissolution of cellulose in ionic liquids, followed by regeneration and spinning into fibers using processes like meltblowing, without the need for chemical derivatization, utilizing low-alpha pulps with high hemicellulose content and lower transition metal and lignin levels, and using water as a non-solvent for regeneration to minimize environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If chemical derivatization or complexation is used to dissolve cellulose (viscose or cuprammonium rayon processes), then cellulose solubility is improved, but production cost increases and environmental harm worsens due to hazardous chemicals and complex regeneration
Solution Approach 1:
The patent changes the fundamental parameter of the solvent system by using ionic liquids instead of traditional chemical derivatives. This parameter change allows cellulose to dissolve without chemical derivatization, eliminating the need for hazardous reagents like carbon disulfide and complex regeneration chemicals while maintaining solubility and enabling fiber formation
Solution Approach 2:
Ionic liquids serve as an intermediary substance that facilitates cellulose dissolution and fiber formation without requiring chemical derivatization. The ionic liquid acts as a mediating solvent that can be removed or regenerated, avoiding the permanent chemical modification and complex regeneration processes required in traditional methods
2Quantity of substance
If high-alpha pulps are used in lyocell processes, then cellulose purity is improved, but production cost increases due to expensive pulp preparation
Solution Approach 1:
The patent changes the solvent parameter to ionic liquids, which have the unique capability to dissolve cellulose from lower-alpha pulps effectively. This parameter change in the solvent system removes the requirement for expensive high-alpha pulp preparation, allowing the use of more economical pulp sources while maintaining fiber quality
3Ease of manufacture
If traditional spinning processes are used, then fiber formation is achieved, but process complexity increases and environmental impact worsens
Solution Approach 1:
The patent extracts and eliminates the complex derivatization and regeneration steps from the traditional spinning process. By using ionic liquids, the process is simplified to direct dissolution, spinning, and solvent removal, taking out the unnecessary intermediate chemical steps while maintaining fiber formation capability
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 reduces production costs, minimizes environmental impact, and avoids the use of hazardous chemicals, enabling the production of cellulose fibers with desirable properties such as smooth surfaces and broad molecular weight distribution, suitable for nonwoven textiles.
Implementation Method 1
dissolving cellulose in an ionic liquid
Implementation Method 2
regenerating the fibers in a non solvent
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present application is directed to a process of dissolving cellulose in an ionic liquid, regenerating the fibers and forming a nonwoven web. In particular it is directed to fibers produced from cellulose dissolved in ionic solvents and extruded by the meltblowing process. Bonded nonwoven webs can be obtained in the process.