Asymmetric Jet Coagulation for High-Strength Polyamide Filaments
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Solution Overview
Problem
Existing processes for producing high strength, high modulus aromatic polyamide filaments face limitations in spinning speed due to friction between filaments and coagulating liquids, leading to decreased filament properties and reduced capacity, especially with symmetric jet coagulators requiring complex and costly layouts.
Innovation Solution
An asymmetric jet coagulation process using a linear spinneret with a single jet channel, where the coagulating liquid is jetted at an angle between 15° and 75° relative to the filaments, reducing friction and allowing higher spinning speeds while maintaining filament quality, and using a spin tube with elongated cross-section to simplify the coagulating unit and reduce clogging risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spinning speed is increased to improve productivity, then output increases, but friction between filaments and coagulating liquid increases leading to decreased filament properties
Solution Approach 1:
The patent uses a jet coagulator that delivers a jetted sheet of coagulating liquid to the filaments. This hydraulic approach creates a controlled fluid environment where the coagulating liquid moves with the filaments, reducing relative velocity and friction while maintaining high spinning speeds for improved productivity.
Solution Approach 2:
The patent changes the velocity parameter of the coagulating liquid to match the filament velocity (within 10-50 km/h range). This parameter adjustment reduces the velocity difference between filaments and coagulating liquid, minimizing friction and preventing deterioration of filament properties even at high spinning speeds.
2Strength
If symmetric jet coagulator is used to reduce friction, then filament properties are maintained, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent employs an asymmetric jet coagulator configuration where the jetted sheet of coagulating liquid is delivered to one side of the filament warp rather than symmetrically from both sides. This asymmetric layout simplifies the device structure and reduces manufacturing complexity while still effectively reducing friction and maintaining filament properties through proper velocity matching.
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 process achieves high strength, high modulus aromatic polyamide filaments with improved yarn properties at high spinning speeds, simpler and cost-efficient equipment layout, and reduced risk of filament sticking, while maintaining or exceeding the quality of symmetric jet layouts.
Implementation Method 1
the jetted coagulating liquid moving downward with the warp of filaments through the spin tube at a velocity of about 50% to 100% of the velocity of the filaments
Implementation Method 2
jetting additional coagulating liquid at a constant flow rate about the filaments in a downward direction
Data Source
AI summary
Process for producing a plurality of high strength, high modulus aromatic polyamide filaments comprising the steps of - extruding an acid solution containing at least 15 % by weight of an aromatic polyamide through linearly arranged orifices in a spinneret thus providing a warp of filaments - passing the warp of filaments through a layer of non-coagulating fluid into a coagulation bath and subsequently - passing the warp through a spin tube, the spin tube having an elongated cross section with at least two opposite sides being parallel to the filament warp with the length of these sides being at least as long as the width of the filament warp - jetting additional coagulating liquid at a constant flow rate about the filaments in a downward direction at an angle between 15° and 75° with respect to the filaments, - the jetted coagulating liquid moving downward with the warp of filaments through the spin tube at a velocity of about 50% to 100% of the velocity of the filaments, the coagulating liquid being jetted through a jet channel from either one side of the spin tube which is parallel to the filament warp, the jet channel having at least the same width as the filament warp