Hydrodynamic Fiber Alignment via Nozzle Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for manufacturing fibers and films from cellulose nanofibrils face challenges in achieving uniform alignment of constituents, leading to local weakening and inferior mechanical properties due to shear gradients and the need for high-viscosity liquids and solvents, which limits the production of high-performance bio-based materials.
Innovation Solution
A continuous, scalable method involving hydrodynamically induced alignment of constituents in a reaction chamber with controlled gel transition using aligning flow streams and electrolytes or acids to produce fibers with high alignment, eliminating the need for co-flowing liquids and reducing shear effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional wet spinning methods are used with co-flowing liquids to achieve fiber alignment, then constituent alignment is improved, but shear gradients cause local weakening and reduce manufacturing precision
Solution Approach 1:
The patent extracts and eliminates the co-flowing liquid component from the spinning process, achieving fiber alignment through nozzle geometry design alone. This removes the source of shear gradients that cause local weakening, while maintaining uniform constituent alignment throughout the fiber cross-section.
Solution Approach 2:
Instead of using external co-flowing liquids to induce alignment, the patent inverts the approach by designing the nozzle geometry itself to create the aligning flow pattern. The nozzle contraction and expansion sections are specifically shaped to generate the required flow characteristics for uniform alignment without additional co-flowing liquids.
2Manufacturing precision
If high-viscosity liquids are used to achieve constituent alignment, then alignment is improved, but the process complexity and chemical usage increase
Solution Approach 1:
The patent changes the geometric parameters of the nozzle rather than altering the viscosity of the spinning liquid. By optimizing the contraction ratio, expansion angle, and length dimensions of the nozzle, the system achieves alignment using standard-viscosity liquids, simplifying the process and reducing chemical requirements.
3Stability of the object's composition
If co-flowing liquids are used to stretch and align constituents, then fiber orientation is improved, but the need for high-speed flow increases energy consumption
Solution Approach 1:
The patent removes the energy-intensive co-flowing liquid system and replaces it with a passive nozzle geometry-based alignment mechanism. The flow alignment is achieved through the inherent flow patterns created by the nozzle contraction and expansion, eliminating the need for high-speed co-flowing liquids and reducing energy consumption.
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 method enables the production of strong, stiff fibers and films with uniform alignment and improved mechanical properties, reducing environmental impact by using fewer chemicals and lower fibril concentrations, resulting in fibers comparable to glass and Kevlar in strength and stiffness.
Implementation Method 1
Acceleration of the central flow in the reaction chamber by at least two opposite, aligning flow streams, essentially perpendicular to the central flow, whereby the long-chained polymer(s) or non-spherical particles are aligned in the flow direction
Implementation Method 2
Gelling of the aligned long-chained polymer(s) or non-spherical particles, through diffusion of salt, chelating agent or acid contained in the aligning flow streams, into the aligned long-chained polymer(s) or non-spherical particles
Implementation Method 3
coagulation of the gel string obtained
Data Source
Figure 1(I)~1(iv)
Figure 2
Figure 3a~3c
AI summary
The invention relates to a continuous, scalable and parallelizable method for preparing strong and stiff fibres (filaments) or films. The fibre or film is prepared by utilizing hydrodynamicaily induced alignment of the constituents of a dispersion in combination with surface-charge controlled gel transition to produce fibres with a high degree of alignment of the constituents (polymer(s), fibrils etc). The invention also relates to the fibres or films so formed.