Regenerated Cellulose Fiber Surface Quality via Stretching
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Solution Overview
Problem
Multifilament fibers produced using the viscose process often fail to meet modern textile strength requirements and face difficulties in processing, especially when used as warp material, leading to issues like increased brittleness and surface defects such as lint, which affect their performance and require additional, economically and ecologically unattractive finishing steps.
Innovation Solution
A method involving the addition of solids like flame retardants and controlled stretching in a second bath, optimizing parameters such as stretching ratios and phosphorus content, to improve fiber surface properties and processability, specifically achieving smoother fibers and reduced lint defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If solids (flame retardant) are added to viscose and stretching is performed in the second bath using known process parameters, then fiber strength is improved, but fiber brittleness increases and surface quality deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the stretching ratio (ε) to be greater than 0.75 and the product of stretching ratio and final withdrawal speed (ε·vend) to be greater than 3600. These specific parameter ranges resolve the contradiction by achieving the desired fiber strength while preventing excessive brittleness and surface defects that would occur with conventional parameters
Solution Approach 2:
The patent implements dynamics by making the stretching process controllable and adjustable through the defined parameters. The stretching ratio and withdrawal speed can be dynamically optimized based on production requirements, allowing the process to adapt between achieving strength versus minimizing brittleness depending on the specific application needs
2Strength
If stretching is increased to achieve required fiber strength, then fiber strength is improved, but lint defects increase and surface quality deteriorates
Solution Approach 1:
The patent resolves this contradiction through precise parameter changes by defining the stretching ratio ε > 0.75 and the product ε·vend > 3600. These optimized parameters enable achieving the required fiber strength while simultaneously maintaining surface quality and minimizing lint defects, unlike conventional approaches where increased stretching always deteriorates surface quality
3Object-affected harmful factors
If additional work steps (finishing and skiving oiling) are performed to improve surface properties, then surface quality is improved, but process complexity and cost increase
Solution Approach 1:
The patent applies preliminary action by optimizing the stretching parameters during the spinning process itself (ε > 0.75 and ε·vend > 3600) to pre-establish good surface properties. This preliminary optimization during spinning eliminates or reduces the need for subsequent finishing and skiving oiling steps, thereby reducing process complexity while maintaining improved surface quality
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 method achieves improved surface quality with reduced lint defects, enhanced strength, and maintains high phosphorus content, allowing for the production of high-quality textile products suitable for protective clothing with minimal additional processing steps.
Implementation Method 1
after the filaments have at least partially coagulated in the spinning bath
Implementation Method 2
there is still a stretching in the Second bath takes place
Data Source
Figure 1
Figure 2
AI summary
In a process for producing regenerated cellulose fibers, in which particles of a flame-retardant solid are incorporated into the fiber, the particles are placed into a mold, the dimension of which in a major axis of the particle is greater than in the two orthogonal minor axes of the particle, and the major axes of the particles in the fiber are aligned in a preferential direction parallel to the spinning direction thereof.