Wet Spinning Apparatus Flow Control for Fiber Quality
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Solution Overview
Problem
Wet spinning apparatuses face issues with turbulent flow and stagnation in the coagulation liquid, leading to fiber breakage and quality deterioration, particularly due to whirlpools and uneven coagulation liquid flow rates, which compromise the quality and performance of synthetic fibers.
Innovation Solution
The wet spinning apparatus controls the flow rate of the coagulation liquid to fall within the range of 0.5 to 1.5 times the drawing speed, using a configuration with a coagulation bath portion and filament running portion with gradually varying cross-sectional areas to prevent counterflow and stagnation, ensuring homogeneous coagulation liquid flow and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the spinning speed is raised to improve productivity, then productivity increases, but turbulent flow of the coagulation liquid becomes more remarkable causing fiber breakage and quality deterioration
Solution Approach 1:
The spinning bath is divided into multiple sections using partition walls, creating separate flow zones. This segmentation allows the coagulation liquid to flow more uniformly through each section, reducing turbulent flow and whirlpools even at high spinning speeds, thereby maintaining fiber quality while improving productivity
Solution Approach 2:
Partition walls are introduced as intermediary structures between the coagulation liquid flow and the filaments. These walls act as mediators that guide and stabilize the liquid flow, preventing direct turbulent interaction with the filaments and reducing breakage during high-speed spinning
2Stability of the object's composition
If rectifying plates are provided to suppress turbulence of coagulation liquid, then turbulence is suppressed, but the flow rate of coagulation liquid at the discharge part becomes too fast causing turbulence of the coagulated filaments
Solution Approach 1:
The discharge area is segmented into multiple discharge ports distributed along the spinning bath. This segmentation distributes the total flow rate across multiple outlets, preventing excessively fast flow at any single discharge point and avoiding turbulence of coagulated filaments while maintaining overall flow stability
Solution Approach 2:
Different regions of the spinning bath have different flow characteristics controlled by local partition wall arrangements. The partition walls create zones with optimized flow rates, ensuring stable coagulation liquid flow in the coagulation zone while controlling discharge flow rates to prevent filament turbulence
3Speed
If the cross-sectional area of the spinning bath is reduced to increase coagulation liquid flow rate, then flow rate increases, but counterflow and stagnation occur causing poor coagulation and fiber breakage
Solution Approach 1:
The spinning bath is segmented into multiple flow channels by partition walls. This segmentation allows the coagulation liquid to maintain higher flow rates in each channel while preventing counterflow and stagnation through the divided flow paths, ensuring uniform coagulation and preventing fiber breakage
Solution Approach 2:
Partition walls are arranged in specific patterns (e.g., alternating sides) to create three-dimensional flow guidance. This spatial arrangement guides the coagulation liquid through the bath in a controlled manner, increasing effective flow rate while preventing dead zones and counterflow that would occur in a simple reduced-cross-section design
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 approach results in high-quality fibers with reduced breakage and filament waste, enabling high-speed spinning while maintaining product quality and productivity by stabilizing the coagulation process and preventing filament entanglement with rectifying plates.
Implementation Method 1
a spinning raw liquid discharged from the nozzle is coagulated by the coagulation liquid and thus formed into coagulated filaments
Implementation Method 2
The coagulation liquid is discharged into the spinning bath from a coagulation liquid discharge port disposed on the rear surface side of the nozzle, and is caused to flow to a running direction of the coagulated filaments
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
Disclosed are a wet spinning apparatus and a wet spinning method, which enable to manufacture fibers with excellent quality by controlling the flow of a coagulation liquid in a spinning bath and which enable to cope with high speed spinning (or high speed drawing). A wet spinning apparatus (1) comprises a spinning bath (2), at one end in which there are provided a nozzle (5) for discharging a spinning raw liquid and coagulation liquid discharge ports (4a) and (4b) for discharging a coagulation liquid (C), at the other end in which there are provided a drawing roll (10) for drawing coagulated filaments (13) and a coagulation liquid recovery portion (3) into which the coagulation liquid (C) flows out. The spinning bath (2) has a coagulation bath portion (2a) having a cross sectional area gradually reduced from one end to the other end, for coagulating the spinning raw liquid, and a filament running portion (2b) having a cross sectional area gradually enlarged from one end to the other end, for allowing the coagulated filaments (13) to run therein.