Flame Resistant Spun Staple Yarns for Protective Apparel
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Solution Overview
Problem
Polysulfonamide (PSA) fibers exhibit low tensile break strength, leading to decreased durability in protective apparel, limiting their use in protective clothing despite their thermal resistance and flexibility.
Innovation Solution
A flame-resistant spun staple yarn is developed, comprising a blend of polymeric staple fibers derived from diaminodiphenyl sulfone monomers, low thermal shrinkage fibers, and antistatic fibers, with the remainder being flame-resistant fibers, ensuring the yarn does not support flames and maintains mechanical integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If polysulfonamide (PSA) fibers are used in protective apparel, then thermal resistance and flexibility are improved, but tensile break strength decreases leading to reduced durability
Solution Approach 1:
The patent applies composite materials by blending PSA fibers with other flame-resistant fibers (such as aramid, modacrylic, or polyacrylic fibers) to create a yarn mixture. This composite approach allows the fabric to inherit the thermal resistance and flexibility of PSA fibers while gaining the tensile strength and durability from the complementary fibers, thus resolving the contradiction between thermal performance and mechanical strength.
Solution Approach 2:
The patent modifies the compositional parameters of the yarn by controlling the weight percentage of PSA fibers within a specific range (at least 25 parts by weight out of 100 total parts). By adjusting this parameter, the invention optimizes the balance between thermal resistance (improved by higher PSA content) and tensile strength (maintained by including other strong fibers), thereby resolving the strength-duration contradiction.
2Ease of operation
If PSA fiber content is increased to improve flexibility and thermal resistance, then comfort is improved, but fabric durability decreases
Solution Approach 1:
The patent uses composite materials by creating a multi-fiber blend where PSA fibers provide flexibility and comfort while other flame-resistant fibers (aramid, modacrylic, polyacrylic) contribute durability and strength. This composite structure allows both comfort and durability requirements to be satisfied simultaneously.
Solution Approach 2:
The patent controls the compositional parameter of PSA fiber content (at least 25 parts by weight out of 100 total parts) to optimize the balance between comfort (improved by PSA flexibility) and durability (maintained by including other strong fibers). This parameter adjustment resolves the contradiction between ease of operation and reliability.
3Object-affected harmful factors
If flame-resistant fibers with high limiting oxygen index are used, then flame resistance is improved, but the yarn may lack mechanical integrity
Solution Approach 1:
The patent applies composite materials by blending flame-resistant fibers with high limiting oxygen index (such as aramid, modacrylic, or polyacrylic fibers) with PSA fibers. This composite approach ensures that the yarn maintains both excellent flame resistance (from the high LOI fibers) and mechanical integrity (from the synergistic combination of fiber properties).
Solution Approach 2:
The patent adjusts the compositional parameters by specifying that flame-resistant fibers constitute the remainder of the yarn after accounting for at least 25 parts by weight of PSA fibers. This parameter control ensures adequate flame resistance while maintaining mechanical integrity through proper fiber distribution and blend composition.
Data Source
AI summary
The invention concerns a flame-resistant spun staple yarns and fabrics and garments comprising these yarns and methods of making the same. The yarns have 50 to 75 parts by weight of a polymeric staple fiber containing a polymer or copolymer derived from a monomer selected from the group consisting of 4,4′diaminodiphenyl sulfone, 3,3′diaminodiphenyl sulfone, and mixtures thereof; 2 to 15 parts by weight of a fiber having low thermal shrinkage; 1 to 5 parts by weight of an antistatic fiber; and the remainder being flame resistant fibers having a limiting oxygen index of 21 or greater, based on 100 total parts by weight of the polymeric fiber, the low thermal shrinkage fiber, the antistatic fiber, and the flame resistant fibers in the yarn.