Polymeric Nanofiber Linear Formation via AC Electrospinning
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Solution Overview
Problem
Existing methods for producing polymeric nanofibers in an electric field, such as static needle spinning and needleless spinning, result in planar layers of randomly interlaced nanofibers with limited tensile strength and productivity, making them unsuitable for industrial-scale applications and further processing by standard textile methods.
Innovation Solution
A method involving the use of a spinning electrode connected to a source of alternating voltage, where polymeric nanofibers are created with alternating electric charges that cluster due to electrostatic forces, forming a linear, three-dimensional structure with improved mechanical properties, allowing for processing by standard textile procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If static needle spinning electrodes or needleless spinning electrodes are used to produce polymeric nanofibers, then a planar layer of nanofibers is formed, but the tensile strength and suitability for further textile processing are limited
Solution Approach 1:
The patent inverts the conventional electrospinning approach by using AC voltage instead of DC voltage, and by collecting nanofibers on a moving belt collector rather than forming them directly as a planar layer. This inversion enables the nanofibers to be deposited in a controlled manner that creates linear formations with improved tensile strength and textile processing suitability
Solution Approach 2:
The patent introduces dynamic elements by using AC voltage (alternating current) instead of static DC voltage, and by employing a moving belt collector. The AC voltage dynamically changes the electric field direction, and the moving belt dynamically collects nanofibers, creating a more robust linear formation with better mechanical properties
2Productivity
If methods based on direct drawing off from multiple nozzles or twisting planar layers are used, then linear formations are created, but productivity remains low and production output is not constant
Solution Approach 1:
The patent achieves continuous production by using a moving belt collector that continuously passes through the electrospinning zone. The AC voltage ensures continuous nanofiber deposition on the moving belt, eliminating the intermittent production and non-constant output associated with methods using multiple nozzles or twisting processes
Solution Approach 2:
The patent extracts the nanofibers directly from the electrospinning process and deposits them onto a moving belt collector in a controlled linear formation. This extraction approach eliminates the need for subsequent twisting or reprocessing steps, thereby increasing productivity and ensuring constant production output
3Shape
If AC voltage is used with a needle-like hollow spinning electrode and rotating aluminium drum collector, then nanofiber alignment is improved, but the flowrate is limited to very low values
Solution Approach 1:
The patent uses a moving belt collector instead of a rotating aluminium drum, and applies AC voltage to create a dynamic electric field that effectively propels nanofibers onto the moving belt at higher flowrates. The combination of AC voltage and moving belt creates more efficient nanofiber deposition dynamics, allowing higher polymer flowrates while maintaining good alignment
4Strength
If a collecting electrode with singular electric charges on a rotating disc is used, then tensile strength of linear formations is improved, but the maximum length is limited by the electrode length
Solution Approach 1:
The moving belt collector serves multiple functions: it collects nanofibers, forms them into linear structures, and can be made arbitrarily long to produce linear formations of any required length. The AC voltage system works effectively with this universal collector, maintaining tensile strength while eliminating the length limitation imposed by fixed electrode geometries
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 method produces polymeric nanofibers with enhanced mechanical properties and productivity, enabling the creation of linear formations that can be processed into threads or yarns, suitable for industrial applications and further utilization in filtration and tissue engineering.
Implementation Method 1
polymeric nanofibers with an electric charge of opposite polarity and/or with segments with an electric charge of opposite polarity are created which cluster together after their creation due to the effect of electrostatic forces
Implementation Method 2
the electric field for electrostatic spinning is formed alternately between the spinning electrode connected to a source of alternating voltage and ions of air and/or gas created and/or supplied to its proximity
Data Source
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AI summary
The invention relates to a method for production of polymeric nanofibers, in which polymeric nanofibers are created due to the action of force of an electric field on solution or melt of a polymer, which is located on the surface of a spinning electrode, whereby the electric field for electrostatic spinning is created alternately between the spinning electrode (1), to which is supplied alternating voltage, and ions (30, 31) of air and/or gas generated and/or supplied to proximity of the spinning electrode (1), whereby according to the phase of the alternating voltage on the spinning electrode (1) polymeric nanofibers with an electric charge of opposite polarity and/or with segments with an electric charge of opposite polarity are created, which after their creation cluster together under the influence of the electrostatic forces into linear formation in the form of a tow or a band, which moves freely in space in direction of gradient of the electric fields away from the spinning electrode (1). The invention further relates to a linear formation from polymeric nanofibers fabricated by this method.