Antimicrobial Polyester Fibers Using Masterbatch Silver Dispersion
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Solution Overview
Problem
Current methods for incorporating antimicrobial agents like silver salts into polyester fibers are hindered by thermal instability, leading to degradation during high-temperature processing, and result in poor laundering properties and uneven distribution, while metallic silver nanoparticles face challenges with clumping and uniform dispersion.
Innovation Solution
A novel polyester fiber composition incorporating a high-melting polymer with a silver salt, copper salt, and a compounding agent, where the silver salt is dispersed with minimal heat history and coated onto polymer pellets using a master batch approach, ensuring uniform distribution and stability during processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silver salts are incorporated into polyester fibers using conventional high-temperature processing methods, then the antimicrobial properties are introduced into the fiber, but the silver salts undergo thermal degradation and decomposition
Solution Approach 1:
The patent changes the temperature parameter by using low-temperature processing methods (below the melting point of polyester) to incorporate silver salts into fibers, thereby preserving the thermal stability of the silver salt while still achieving effective antimicrobial incorporation
Solution Approach 2:
The patent uses a master batch carrier as an intermediary material to deliver silver salts into the fiber during extrusion. The master batch acts as a protective vehicle that prevents direct thermal exposure of silver salts to high processing temperatures, thus maintaining their stability
2Reliability
If metallic silver nanoparticles are used to provide antimicrobial properties, then the antimicrobial activity is enhanced, but the nanoparticles clump together and fail to disperse uniformly
Solution Approach 1:
The patent uses a master batch carrier as an intermediary that prevents nanoparticle aggregation during processing. The carrier material keeps nanoparticles separated and evenly distributed throughout the fiber matrix, solving the clumping problem while maintaining enhanced antimicrobial activity
Solution Approach 2:
The patent creates a composite material system combining silver nanoparticles with a master batch carrier material. This composite approach allows the nanoparticles to be delivered in a controlled manner that prevents aggregation while maintaining their antimicrobial effectiveness
3Ease of manufacture
If silver salts are added during high-temperature fiber processing, then the antimicrobial properties are incorporated into the fiber structure, but the silver salts decompose and lose their efficacy
Solution Approach 1:
The patent changes the processing temperature parameter from high-temperature (above polyester melting point) to low-temperature (below melting point) processing, enabling silver salt incorporation while preserving their chemical integrity and antimicrobial efficacy
Solution Approach 2:
The patent prepares a master batch carrier containing silver salts in advance, before the fiber extrusion process. This preliminary preparation allows the silver salts to be pre-positioned in a stable form that will be gradually released or distributed during the subsequent low-temperature fiber formation 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 fibers exhibit sustained antimicrobial efficacy against a wide range of bacteria and fungi, including resistant strains, maintaining activity after repeated washings and dry cleaning, with effective silver ion release and distribution.
Implementation Method 1
ultimately antimicrobial activity is mediated through the dissolution of silver ions into the bacterial microenvironment
Implementation Method 2
The reaction of aqueous solutions of silver nitrate and sulfuric acid to form silver sulfate... Silver salts are generally known to be thermally and photochemically unstable, forming brown, gray or black products. Silver sulfate may be reduced to its metallic state, with the corresponding oxidation of chemical elements in its environment.
Data Source
AI summary
High-melting antimicrobial polymer fibers and antimicrobial fabrics comprising such fibers are prepared by preparing a masterbatch of polymer pellets (e.g., PET), silver and copper salts, and a compounding agent which provides free flowing polymer pellets which can be prepared in advance, with a long shelf life. Polymer masterbatches prepared by the methods of the invention can produce limited color or off-white antimicrobial fibers and fabrics using conventional melt spinning manufacturing methods. Fabrics incorporating fibers of the present invention are potent inhibitors of Athlete's foot fungi, gram negative and gram positive bacteria, and drug resistant pathogens.