Semi-dull Polyester Yarns via Silicated Diol Modification
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Solution Overview
Problem
Conventional polyester fibers face challenges in dyeability due to their hydrophobic nature and tight molecular arrangement, requiring high temperature and pressure for dyeing, which is energy-intensive and costly, and also pose environmental concerns due to slow degradation.
Innovation Solution
The development of semi-dull polyester drawn yarns through a modified polyester production process involving esterification and polycondensation of terephthalic acid, ethylene glycol, main chain silicated diol, fluorinated dicarboxylic acid, and doped Bi2O3, which enhances dyeing performance and natural degradation by increasing molecular free volume and oxygen reduction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional PET fiber is dyed with disperse dyes at high temperature and high pressure to ensure dye uptake, then dyeing effectiveness is improved, but energy consumption increases and dyeing time is extended
Solution Approach 1:
The patent introduces main chain silicated diol into the PET molecular chain, which increases the free volume and creates more accessible dyeing sites. This chemical modification changes the physical parameters of the fiber structure, allowing disperse dyes to penetrate and attach more effectively at lower temperatures and pressures, thereby reducing energy consumption while maintaining or improving dye uptake
Solution Approach 2:
The invention creates a composite polyester structure by incorporating silicated diol units into the PET chain. This composite molecular structure combines the properties of PET with the hydrophilic characteristics of siloxane groups, enhancing dye accessibility and reducing the harsh conditions needed for effective dyeing
2Manufacturing precision
If conventional PET fiber is dyed with disperse dyes at high temperature and high pressure to ensure dye uptake, then dyeing effectiveness is improved, but dyeing time is extended
Solution Approach 1:
The silicated diol modification changes the molecular packing and free volume parameters of PET, creating more pathways and sites for dye penetration. This structural parameter change accelerates the dyeing kinetics, allowing sufficient dye uptake to be achieved in shorter times at moderate temperatures
Solution Approach 2:
The introduction of silicated diol creates a more open, porous-like molecular structure within the PET chains, increasing free volume and accessibility to interior dyeing sites. This structural openness allows dye molecules to reach binding sites more quickly, reducing overall dyeing time
3Strength
If PET fiber maintains its tight molecular arrangement for mechanical strength, then strength is improved, but dyeability deteriorates
Solution Approach 1:
The patent applies local quality modification by introducing silicated diol units at specific positions within the PET molecular chain. These localized modifications create hydrophilic zones and increase free volume without disrupting the overall crystalline structure and mechanical integrity of the fiber, achieving both strength retention and improved dyeability
Solution Approach 2:
The invention creates a composite molecular structure where silicated diol segments are integrated into the PET chain. This composite structure combines the strength-providing crystalline PET regions with the dye-accessible amorphous siloxane-modified regions, achieving both mechanical strength and improved dyeability
4Strength
If polyester fiber is produced with standard composition for mechanical properties, then mechanical properties are maintained, but degradation resistance increases causing environmental pollution
Solution Approach 1:
The introduction of silicated diol and fluorinated dicarboxylic acid modifies the chemical composition parameters of PET, creating hydrolytically vulnerable bonds within the molecular chain. These compositional changes maintain mechanical strength through proper molecular architecture while introducing pathways for environmental degradation, reducing persistence and pollution
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 reduces dyeing temperature and time, decreases energy consumption, and significantly accelerates the degradation of polyester fibers, improving dye uptake and color fastness while maintaining mechanical properties and environmental sustainability.
Implementation Method 1
the product of the esterification and the successive polycondensation reactions of evenly mixed terephthalic acid, ethylene glycol, main chain silicated diol, fluorinated dicarboxylic acid
Implementation Method 2
the product of the esterification and the successive polycondensation reactions of evenly mixed terephthalic acid, ethylene glycol, main chain silicated diol, fluorinated dicarboxylic acid
Implementation Method 3
the added material is known as matting agent. In polyester fiber production, titania (TiO2) is widely used as matting agent
Implementation Method 4
the glare can be dimmed by guiding the reflective light to different directions through a small amount of particles with heterologous refractive index
Implementation Method 5
the glare can be dimmed by guiding the reflective light to different directions through a small amount of particles with heterologous refractive index
Implementation Method 6
doped Bi2O3, which enhances dyeing performance and natural degradation by increasing molecular free volume and oxygen reduction efficiency
Implementation Method 7
doped Bi2O3, which enhances dyeing performance and natural degradation by increasing molecular free volume and oxygen reduction efficiency
Data Source
AI summary
A type of semi-dull polyester drawn yarns and preparing method thereof are disclosed. The preparing method is to melt spinning a modified polyester with FDY technique, wherein the modified polyester is the product of the esterification and the successive polycondensation reactions of evenly mixed terephthalic acid, ethylene glycol, main chain silicated diol, fluorinated dicarboxylic acid, matting agent and doped Bi2O3, in which the main chain silicated diol could be dimethylsiloxane diol, dimethyldiphenyldisiloxane glycol or tetramethyldisiloxane diol, and in which the fluorinated dicarboxylic acids could be 2,2-difluoro-1,3-malonic acid, 2,2-difluoro-1,4-succinic acid, 2,2-difluoro-1,5-glutaric acid or 2,2,3,3-tetrafluoro-1,4-succinic acid. The obtained fiber has a dye uptake of 87.5-91.8% when dyed at 120° C., and has an intrinsic viscosity drop of 18-26% when stored at 25° C. and R.H. 65% for 60 months. This invention features a method with ease of application and a product with good dyeing and degradation performance.