Rotary Solution Spinning for Uniform Nanofiber Web Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing very fine fibers and fibrous webs are inefficient and lack a high throughput process to achieve uniformity, often resulting in agglomeration of atomized droplets into larger entities, which is not suitable for selective barrier applications like filters and medical gowns.
Innovation Solution
A high-speed rotary sprayer process using a rotating conical nozzle with a concave inner surface and forward surface discharge edge, where a spinning solution with polymers and solvents is distributed along the nozzle's concave surface to form separate fibrous streams through centrifugal force, optionally assisted by a shaping fluid and electrical field, to produce fibers with diameters less than 1,000 nm for uniform web formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If rotary sprayers are used to atomize the spinning solution, then the spinning solution can be broken into droplets, but the atomized droplets agglomerate into larger entities instead of forming fine fibers
Solution Approach 1:
The patent segments the spinning solution into separate fibrous streams as it travels along the concave inner surface of the rotating conical nozzle, preventing agglomeration of droplets. The segmentation occurs through the geometric configuration of the nozzle surface that divides the liquid stream into multiple fine streams that solidify into individual fibers before collection.
Solution Approach 2:
The patent employs a high-speed rotating conical nozzle where the rotation speed and concave surface geometry dynamically control the formation and distribution of fibrous streams. The dynamic rotation creates centrifugal forces that distribute the spinning solution uniformly along the concave surface, enabling continuous production of fine fibers with consistent diameter.
2Productivity
If a high speed rotary sprayer is used to form separate fibrous streams, then very fine fibers can be produced with high throughput, but the process requires precise control of spinning solution distribution along the nozzle surface
Solution Approach 1:
The patent uses a conical nozzle with a concave inner surface that provides a curved pathway for the spinning solution. This curvature geometry naturally guides and distributes the liquid stream along the rotating surface, creating uniform fibrous streams without requiring complex external control mechanisms. The spherical/conical geometry simplifies the distribution process while maintaining precision.
3Device complexity
If no electrical field is applied, then the process can operate simpler and at higher throughput, but fiber separation and uniformity may be insufficient
Solution Approach 1:
The patent introduces an electrical field as an intermediary mechanism to enhance fiber separation and uniformity when needed. The electrical field acts as a mediator that interacts with the charged or polarized fibrous streams, providing additional separation control without fundamentally changing the core mechanical spinning process. This allows the system to maintain simplicity while offering enhanced precision when required.
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 process enables the production of very fine, continuous fibers with uniform diameters ranging from 100 nm to 500 nm, facilitating high throughput and uniform fibrous web creation, suitable for selective barrier applications without the need for electrical fields, which improves fiber separation and collection efficiency.
Implementation Method 1
The centrifugal force supplied by the rotary sprayers produces enough shear to cause the paint to become atomized
Implementation Method 2
The shaping fluid and electrical field draw the atomized paint to the target device
Implementation Method 3
forming separate fibrous streams from the spinning solution while the solvent vaporizes to produce polymeric fibers
Data Source
AI summary
The invention relates to a process for forming fibers from a spinning solution utilizing a high speed rotary sprayer. The fibers can be collected into a uniform web for selective barrier end uses. Fibers with an average fiber diameter of less that 1,000 nm can be produced.