Flame-Retardant Viscose Fibers via Organophosphoric Additive Integration
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Solution Overview
Problem
Conventional viscose fibers are easily flammable, and previous attempts to impart flame-retardant properties have been unsatisfactory, often compromising mechanical resistance and stability during the spinning process.
Innovation Solution
Incorporating organophosphoric compounds, such as 1,3,2-dioxaphosphorinan-2,2'-oxy-bis-(5,5-dimethyl-2-sulphide), and other additives like tetrabromobisphenol A and sodium silicate into the cellulose viscose solution, which are mixed homogeneously using static or dynamic mixers and filtered to prevent coagulation, ensuring the fibers' mechanical properties are maintained while enhancing flame resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If flame-retardant additives are added to viscose mass to be spun, then flame-retardant properties are achieved, but mechanical resistance properties of the yarn are reduced
Solution Approach 1:
The patent applies preliminary action by adding flame-retardant additives to the cellulose alkali before xanthation occurs, rather than adding them later to the viscose mass. This early incorporation allows the additives to be integrated into the fiber structure during formation, preventing mechanical property degradation while maintaining flame-retardant effectiveness
Solution Approach 2:
The patent changes the parameter of additive form from solid powder to soluble derivative. By using soluble derivatives of flame-retardant substances, the additives can be uniformly distributed in the viscose solution without causing the mechanical resistance reduction associated with solid particle additions, thus resolving the contradiction between flame-retardancy and mechanical strength
2Object-affected harmful factors
If solid flame-retardant additives are applied as powders to the yarn, then flame-retardant characteristics are provided, but the treatment is inappropriate for preventing combustion
Solution Approach 1:
The patent transforms the physical state parameter of the flame-retardant additives from solid powder to soluble derivative form. This parameter change enables the additives to be effectively incorporated into the viscose solution and uniformly distributed throughout the fiber, making the treatment appropriate and effective for combustion prevention rather than merely surface-level powder application
3Object-affected harmful factors
If flame-retardant additives are added to the viscose solution, then flame resistance is enhanced, but coagulation occurs during spinning
Solution Approach 1:
The patent applies preliminary action by incorporating flame-retardant additives into the cellulose alkali at the beginning of the process, before xanthation and viscose formation. This early incorporation ensures stable integration of the additives into the fiber structure during spinning, preventing coagulation issues that would occur with later addition to the viscose mass
Solution Approach 2:
The patent uses soluble derivatives as intermediaries between the flame-retardant substances and the viscose system. These soluble derivatives act as mediators that provide flame-retardant properties while maintaining compatibility with the viscose solution, preventing coagulation during the spinning process
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 produces continuous flame-retardant viscose fibers with improved mechanical resistance and increased flame-development resistance, reducing production costs and maintaining fiber stability throughout the spinning phase, as evidenced by certifications such as BS5852 (1990) and enhanced LOI index from 18 to 28-30, preventing combustion and heat propagation.
Implementation Method 1
Incorporating organophosphoric compounds, such as 1,3,2-dioxaphosphorinan-2,2'-oxy-bis-(5,5-dimethyl-2-sulphide), and other additives like tetrabromobisphenol A and sodium silicate into the cellulose viscose solution, which are mixed homogeneously using static or dynamic mixers
Implementation Method 2
filtered to prevent coagulation, ensuring the fibers' mechanical properties are maintained while enhancing flame resistance
Implementation Method 3
the cellulose is regenerated from the viscose in fibrous form: at the outlet of the die hole the viscose encounters the coagulation bath which causes the coagulation of the viscose and hydrolysis of the xanthogenate
Implementation Method 4
enhanced LOI index from 18 to 28-30, preventing combustion and heat propagation
Data Source
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AI summary
The present invention relates to a process for the production in continuous of cellulose-based flame-retardant fibres or filaments and textile articles obtained therefrom, comprising the predispersion in water of an organophosphoric additive, the dosing and mixing of the aqueous predispersion in a solution of cellulose xanthogenate, the filtration of the mixed solutions and spinning in a regenerating and coagulation bath.