Lyocell and Flame Resistant Fiber Blend for Protective Garments

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Solution Overview

Problem

Existing flame-resistant fabrics for protective garments often require the use of modacrylic fibers or post-treatment with flame retardants, which can be hazardous and limit the integration of lyocell fibers beyond a certain percentage without compromising flame resistance.

Innovation Solution

A blend of lyocell fibers and inherently flame-resistant fibers, such as Polybenzimidazole (PBI) or flame-resistant rayon, that does not require modacrylic or post-treatment for flame resistance, allowing for a fabric composition where lyocell fibers can constitute a significant portion without compromising safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If lyocell fibers are blended with flame resistant fibers, then comfort and moisture management are improved, but flame resistance deteriorates when lyocell content exceeds a certain percentage

Engineering Contradiction:
ImprovecomfortVSAvoidflame resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent creates a composite fiber blend combining lyocell fibers with inherently flame-resistant fibers (such as aramids, polyimides, or modacrylic) to achieve both comfort and flame resistance. This composite approach allows the fabric to maintain flame resistance even at high lyocell content levels (up to 95%) because the flame-resistant fibers provide inherent protection without requiring post-treatment.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The flame-resistant fibers used in the blend provide self-protection through their inherent flame-resistant properties, eliminating the need for external flame retardant treatments. The fibers naturally resist ignition and flame propagation, allowing the lyocell component to contribute its comfort and moisture management qualities without compromising safety.

Inventive Principle:
Principle #25Self-service

2Reliability

If modacrylic fibers are used for flame resistance, then flame resistance is improved, but hazardous gas or acid emissions occur during flame extinguishment

Engineering Contradiction:
Improveflame resistanceVSAvoidhazardous gas or acid emissions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces modacrylic fibers with inherently flame-resistant fibers that do not produce harmful emissions when exposed to flame. Fibers such as aramids, polyimides, and other FR fibers provide the necessary flame protection through char formation and heat barrier mechanisms without releasing toxic gases or acids, thus converting a harmful flame-retardant approach into a safe one.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention changes the chemical composition parameters of the flame-resistant fiber blend by selecting fibers with specific flame-resistant mechanisms that do not involve harmful emissions. By adjusting the fiber type and blend ratio, the fabric achieves flame resistance through physical barrier and char formation mechanisms rather than chemical emission-based flame extinction.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If post-treatment with flame retardants is applied, then flame resistance is improved, but the process complexity and cost increase

Engineering Contradiction:
Improveflame resistanceVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent incorporates inherently flame-resistant fibers during the fiber blending stage, before fabric manufacturing. This preliminary action ensures that the flame resistance is built into the material itself, eliminating the need for subsequent post-treatment processes. The flame-resistant properties are intrinsic to the fiber blend, simplifying the overall manufacturing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flame-resistant fibers provide self-protection through their inherent properties, eliminating the need for external flame retardant treatments. The fibers naturally resist ignition and flame propagation, allowing the lyocell component to contribute its comfort and moisture management qualities without compromising safety.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS9212434B2Blend of lyocell and flame resistant fibers for protective garments
Publication Date: 2015.12.15 PBI PERFORMANCE PRODUCTS INC

AI summary

A unique blend of fibers used to create a yarn or fabric useful in protective garments including a lyocell fiber, and a flame resistant fiber that is not a modacrylic and/or does not require the emission of gases and/or acids for flame resistance. The lyocell fiber is approximately 5% to 55% of the blend, and the flame resistant fiber is approximately 45% to 95% of the blend. The resulting fabric requires no post treatment for flame resistance.