Acrylic-fiber manufacturing method
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Solution Overview
Problem
The existing methods for manufacturing acrylic fibers using wet spinning techniques require a large amount of water and prolonged washing times to remove organic solvents, which is inefficient.
Innovation Solution
A method involving the alternate spraying of water and pressing of coagulated filaments with nip rolls to remove organic solvents, applying a nip pressure of 0.2 MPa or higher, and performing this process eight or more times, without the use of a water bath.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If organic solvent is removed by washing in a water bath, then organic solvent removal is achieved, but water consumption increases and washing time is prolonged
Solution Approach 1:
The continuous water bath washing process is segmented into discrete stages: spraying water onto filaments, pressing with nip rolls, and repeating the cycle. This segmentation allows for more efficient solvent removal by combining mechanical pressing with periodic water spraying, reducing overall water consumption while achieving effective organic solvent removal.
Solution Approach 2:
The patent replaces the traditional hydrodynamic washing system (water bath immersion) with a mechanical pressing system (nip rolls) combined with sprayed water. The mechanical pressing action physically extracts organic solvent from filaments, substituting the need for large volumes of water for solvent removal.
2Loss of substance
If organic solvent is removed by washing in a water bath, then organic solvent removal is achieved, but washing time is prolonged
Solution Approach 1:
The patent applies preliminary mechanical pressing action before or during the washing process. By using nip rolls to press filaments and physically extract organic solvent beforehand, the subsequent water washing requires less time to achieve complete solvent removal, thereby reducing total washing time.
Solution Approach 2:
The washing process uses periodic action by alternately spraying water onto filaments and pressing with nip rolls in repeated cycles. This periodic combination of water spraying and mechanical pressing accelerates solvent removal compared to continuous water bath washing, reducing overall washing time while maintaining effectiveness.
3Productivity
If wet-spun acrylic fiber is dried immediately after coagulation, then drying efficiency is improved, but fibers adhere to one another
Solution Approach 1:
The patent performs preliminary washing and organic solvent removal actions before the drying stage. By removing organic solvent through the spraying and pressing process beforehand, the fibers are prepared for drying without the adhesion problem that would occur if dried immediately after coagulation, enabling both efficient drying and fiber non-adhesion.
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 method effectively removes solvents from acrylic fibers within a short period without using a water bath, improving efficiency and reducing water consumption.
Implementation Method 1
spraying water onto coagulated filaments obtained by solidifying the spinning solution
Implementation Method 2
an acrylic polymer is dissolved in an organic solvent
Implementation Method 3
pressing the coagulated filaments with nip rolls
Implementation Method 4
the nip rolls apply a nip pressure of 0.2 MPa or higher
Data Source
Figure 1a~3
Figure 4A~4B
AI summary
The present invention relates to a method for manufacturing an acrylic fiber using a spinning solution in which an acrylic polymer is dissolved in an organic solvent, the method comprising a washing step of alternately performing spraying 3 water onto coagulated filaments obtained by solidifying the spinning solution and pressing the coagulated filaments with nip rolls 2. Preferably, the nip rolls apply a nip pressure of 0.2 MPa or higher. Thus, a method for manufacturing an acrylic fiber with which an organic solvent in the acrylic fiber can be removed within a short period of time without using a water bath is provided.