Cellulose Filament Winding With Partial Washing and Coiled Drying

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Solution Overview

Problem

Existing cellulose filament production processes face inefficiencies in solvent recovery and filament quality due to stringent environmental regulations, leading to quality defects and high operational costs, particularly in the lyocell process.

Innovation Solution

A device and method for producing cellulose filaments that omit or minimize solvent washing and drying before winding, allowing the filaments to be wound while still containing solvent, followed by partial washing and drying in a coiled form, enhancing filament strength and plasticity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If complete solvent washing and drying is performed before winding, then filament quality is improved, but production time and energy consumption increase

Engineering Contradiction:
Improvefilament qualityVSAvoidproduction time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary washing and drying actions during the coagulation process itself, rather than as separate post-processing steps. The coagulation bath is designed to simultaneously solidify the filament and remove solvent, and the filament is dried in situ on the spool before complete solidification, thereby reducing total production time while maintaining quality

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent establishes a continuous process where solvent removal, drying, and winding occur in an integrated sequence without interruption. The filament is continuously dried on the rotating spool and continuously wound, eliminating idle time between processing stages and maintaining constant productive action throughout the manufacturing cycle

Inventive Principle:
Principle #20Continuity of useful action

2Manufacturing precision

If complete solvent washing and drying is performed before winding, then filament quality is improved, but energy consumption increases

Engineering Contradiction:
Improvefilament qualityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent performs preliminary drying actions during the coagulation process itself, rather than as separate post-processing steps. The filament is dried in situ on the spool before complete solidification, thereby reducing total energy consumption while maintaining quality

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent establishes a continuous process where solvent removal, drying, and winding occur in an integrated sequence without interruption. The filament is continuously dried on the rotating spool and continuously wound, eliminating idle time between processing stages and maintaining constant productive action throughout the manufacturing cycle

Inventive Principle:
Principle #20Continuity of useful action

3Loss of substance

If washing unit is included in the device, then solvent recovery is improved, but device complexity increases

Engineering Contradiction:
Improvesolvent recoveryVSAvoiddevice complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The patent merges the washing function with the coagulation unit and the drying function with the winding unit. The coagulation bath simultaneously solidifies the filament and removes solvent, and the filament is dried in situ on the rotating spool during winding, thereby reducing device complexity while maintaining solvent recovery effectiveness

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent designs the coagulation unit to perform multiple functions (solidification and solvent removal) and the winding unit to perform multiple functions (winding and in situ drying). This multi-functionality reduces the need for separate dedicated units, thereby simplifying the overall device structure while maintaining effective solvent recovery

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 increases filament elongation by up to 50% and strength by up to 20%, improving processing efficiency and reducing filament defects, while simplifying further processing and reducing chemical usage.

Implementation Method 1

a coagulation unit for solidifying the filaments

Methodology Applied
Scientific EffectCoagulation: Coagulation

Implementation Method 2

where solvent exchange takes place, resulting in the precipitation of the initially dissolved cellulose as thread-like products

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Implementation Method 3

a partial washing unit for washing the cellulose filaments or for extracting a cellulose solvent from the cellulose filaments

Methodology Applied
Scientific EffectLiquid-Liquid Extraction: Liquid-Liquid Extraction

Data Source

PatentEP4650499A1Winding device and winding method
Publication Date: 2025.11.19 AUROTECH GMBH
  • EP4650499A1 patent drawingFigure 1~2
  • EP4650499A1 patent drawingFigure 3~4
  • EP4650499A1 patent drawing

AI summary

The invention relates to a device for solidifying and winding cellulose multifilaments, comprising an extrusion unit with at least 10 openings for forming filaments, a coagulation unit for solidifying the filaments, and a thread winder for winding the cellulose filaments, characterized in that the device contains no or only a partial washing unit for washing the cellulose filaments or for extracting a cellulose solvent from the cellulose filaments between the coagulation unit and the thread winder; and a method for winding cellulose multifilaments.