Flame-Retardant Textile Composite With Low Thermal Shrinkage
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Solution Overview
Problem
Existing flame retardant garments using thermoplastic and/or meltable fibers exhibit high thermal shrinkage when exposed to high temperatures or flames, making it challenging to meet NFPA 2112 compliance standards for low thermal shrinkage, and they are often expensive, difficult to dye, and lack adequate abrasion resistance.
Innovation Solution
A composite article comprising a textile layer with a heat stable spun yarn made from non-meltable fibers and an adhesive layer containing a polymer resin and expandable graphite, where the expandable graphite expands upon heating to form a char that insulates and prevents further burning, while maintaining low thermal shrinkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermoplastic and/or meltable fibers are used in flame retardant garments, then the garment provides enhanced protection and can be lightweight, but the thermal shrinkage increases significantly when exposed to high temperatures
Solution Approach 1:
The patent uses composite materials by combining heat stable non-meltable fibers (such as aramid, PBI, or PBO) with thermoplastic fibers in a blended yarn structure. This composite approach allows the garment to benefit from both the flame protection and lightweight properties of thermoplastics while the heat stable fibers prevent thermal shrinkage, achieving NFPA 2112 compliance with shrinkage below 21%.
2Reliability
If inherently flame retardant textiles (such as aramid, PBI, PBO) are used, then flame resistance is improved, but the cost increases significantly
Solution Approach 1:
The patent applies local quality by using heat stable non-meltable fibers strategically in the composite structure to provide flame resistance where needed, while combining them with cost-effective thermoplastic fibers for the remaining portions of the fabric. This localized approach to flame resistance reduces overall material costs while maintaining NFPA 2112 compliance.
3Reliability
If inherently flame retardant fibers (aramid, PBI, PBO) are used, then flame protection is enhanced, but the ease of dyeing and printing deteriorates
Solution Approach 1:
The patent uses local quality by combining heat stable non-meltable fibers with conventional thermoplastic fibers that have excellent dyeability and printability. The thermoplastic portion of the blended yarn accepts dyes and prints easily, while the heat stable fibers provide the necessary flame protection, thus resolving the contradiction between flame protection and ease of manufacturing.
4Reliability
If inherently flame retardant fibers are used, then flame resistance is improved, but the abrasion resistance becomes inadequate
Solution Approach 1:
The patent employs composite materials by blending heat stable non-meltable fibers with durable thermoplastic fibers known for their abrasion resistance. This composite structure allows the thermoplastic component to provide the necessary mechanical strength and abrasion resistance, while the heat stable fibers ensure flame resistance and NFPA 2112 compliance.
5Reliability
If inherently flame retardant fibers are used, then flame protection is enhanced, but the tactile comfort and water absorption properties deteriorate
Solution Approach 1:
The patent uses composite materials combining heat stable non-meltable fibers with thermoplastic fibers that offer superior tactile comfort and moisture management properties. The thermoplastic component provides softness, breathability, and water absorption characteristics similar to conventional garments, while the heat stable fibers deliver flame protection, achieving a balance between comfort and safety.
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 composite article achieves low thermal shrinkage, excellent flame resistance, and maintains the appearance and weight of traditional garments, with improved colorfastness, printing, and abrasion resistance, while being compliant with NFPA 2112 standards.
Implementation Method 1
an adhesive layer containing a polymer resin and expandable graphite, where the expandable graphite expands upon heating to form a char that insulates and prevents further burning
Implementation Method 2
the heat stable spun yarn does not shrink more than 5% in an oven test at 260°C for 5 minutes
Implementation Method 3
an adhesive layer bonded to the textile layer; wherein the adhesive layer comprises a polymer resin and an expandable graphite
Data Source
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AI summary
Described are composite articles containing heat stable spun yarn containing textiles that exhibit low flammability and thermal shrinkage resistance. A composite article is described comprising (1) a textile layer comprising a heat stable spun yam and (2) a heat reactive layer. The articles can be National Fire Protection Agency ("NFPA") 2112 compliant.