Polyarenazole Microfilaments Electrostatic Spinning
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Solution Overview
Problem
There is a need for nanofibers with improved properties for applications such as filtration media, cell & tissue cultures, and specialty textiles, as existing low denier fibers lack sufficient strength and uniformity.
Innovation Solution
The development of polyarenazole microfilaments with diameters ranging from 20 to 800 nm, made from polypyridazole, polybenzoxazole, or polybenzothiazole polymers, using a process involving extrusion through a spinneret with applied voltage and collection on a surface with opposite polarity, and optionally passing through an air gap with air flow, to produce yarns and fabrics with enhanced tenacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional low denier fibers are used, then production cost is reduced, but fiber strength and uniformity are insufficient
Solution Approach 1:
The patent changes the chemical composition parameters by using polyarenazole polymers with specific inherent viscosity ranges (20-50 dl/g) and controls processing parameters including spinneret voltage (1-300 kV), collection surface voltage (0-10 kV), and air gap dimensions to achieve consistent nanofiber production with improved strength properties
Solution Approach 2:
The patent replaces conventional mechanical spinning methods with electrostatic field-based spinning, where high voltage applied to the spinneret creates electrostatic forces that draw and solidify polymer jets into nanofibers, eliminating complex mechanical drawing and texturizing equipment
2Manufacturing precision
If fiber diameter is reduced to nanofiber range, then filtration and textile performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent introduces an air gap as an intermediary zone between the spinneret and collection surface, where controlled air flow acts as a mediator to stabilize polymer jet formation and enable consistent nanofiber diameter control without requiring extremely precise mechanical positioning
Solution Approach 2:
The patent adds the electrical dimension by applying high voltage to the spinneret and collection surface, creating an electrostatic field that provides a new dimension of control over fiber formation, enabling precise diameter control through voltage adjustment rather than mechanical means
3Strength
If electrostatic field spinning is used, then fiber strength is improved, but energy consumption increases
Solution Approach 1:
The patent applies high voltage (1-300 kV) only during the critical fiber formation moment in the air gap, rather than continuously, allowing the electrostatic field to do just enough work to solidify and orient the polymer jets into strong nanofibers, then the field is reduced or turned off during collection and winding operations
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 resulting polyarenazole microfilaments and yarns exhibit increased strength and uniformity, with inherent viscosities greater than 20g/dl, suitable for high-strength applications in various end uses, including filtration and textile products.
Implementation Method 1
extruding a solution comprising polypyridazole, polybenzoxazole (PBO), or polybenzothiazole (PBZ) polymer through a spinneret having a first applied voltage; and collecting the extruded polypyridazole, polybenzoxazole (PBO), or polybenzothiazole (PBZ) polymer on a collection surface optionally having a second applied voltage that is opposite in polarity to the first applied voltage
Implementation Method 2
passing the extruded polyarenazole polymer solution through an air gap. The extruded polymer can be accelerated in the air gap by providing air flow along the direction between the spinneret and collection surface
Data Source
AI summary
Provided is a polymer filament having an average diameter of about 20 to 5000 nm, the filament comprising a polyarenazole polymer having an inherent viscosity of greater than about 20g/dl. Also provided are yarns comprising such filaments. Additional aspects concern fabrics and garments comprising such filaments and/or yarns.