Polyamide Artificial Hair Fiber Shape Memory Flame Resistance

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Solution Overview

Problem

Artificial hair fibers used in wigs lack the ability to alter and recover styles easily, and they often suffer from poor heat resistance, self-extinguishing, and glossiness issues, limiting user customization and safety.

Innovation Solution

Development of artificial hair fibers with a specific resin composition including polyamide, fine particles, and controlled modulus of elasticity, which enables superior shape altering and recovering characteristics, self-extinguishing properties, and glossiness similar to human hair.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If vinyl chloride resin is used for artificial hair fiber, then workability and cost are improved, but heat resistance deteriorates causing fusion and damage at 100°C or higher

Engineering Contradiction:
ImproveworkabilityVSAvoidheat resistance
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent changes the material parameter from vinyl chloride resin to polyamide resin, fundamentally altering the thermal properties of the fiber. This material substitution enables the fiber to withstand temperatures of 100°C or higher without fusion or damage, while maintaining workability through established polyamide processing techniques.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite fiber structure by combining polyamide resin with specific additives including silica fine particles (0.1-10 μm) at 1-20 parts by mass per 100 parts polyamide, and titanium dioxide at 1-10 parts by mass per 100 parts polyamide. This composite approach enhances both heat resistance and mechanical properties while maintaining manufacturability.

Inventive Principle:
Principle #40Composite materials

2Temperature

If polyamide is used for artificial hair fiber, then heat resistance and curl setting characteristics are improved, but the ability to alter and recover styles is limited

Engineering Contradiction:
Improveheat resistanceVSAvoidstyle altering and recovery capability
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The patent optimizes the molecular weight parameter of polyamide to 60,000-150,000 and controls the modulus of elasticity within 100-10,000 N/mm², creating a balance between thermal stability and shape flexibility. This parameter optimization enables the fiber to withstand high temperatures while maintaining the ability to be styled and recover its original form.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces silica fine particles (0.1-10 μm) as a localized component within the polyamide matrix, creating regions with different thermal and mechanical properties. This local quality enhancement provides heat resistance in the silica-containing regions while maintaining the overall flexibility and shape memory of the polyamide fiber.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If artificial hair fiber is designed for shape memory, then shape recovering characteristics are improved, but self-extinguishing and dripping-resistant characteristics may deteriorate

Engineering Contradiction:
Improveshape recovering characteristicsVSAvoidself-extinguishing and dripping-resistant characteristics
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent incorporates silica fine particles and titanium dioxide into the polyamide matrix, creating a composite structure that enhances flame resistance. These inorganic particles act as heat barriers and radical scavengers, improving self-extinguishing characteristics while maintaining the polyamide's shape memory properties through optimized molecular weight and modulus control.

Inventive Principle:
Principle #40Composite materials

4Illumination intensity

If artificial hair fiber is designed for high glossiness, then appearance is improved, but heat resistance and shape stability may deteriorate

Engineering Contradiction:
ImproveglossinessVSAvoidheat resistance
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent uses titanium dioxide fine particles (1-10 parts by mass per 100 parts polyamide) to enhance the glossiness and brightness of the fiber surface. The high refractive index of titanium dioxide provides excellent light reflection properties, creating a shiny appearance while the polyamide base material and silica particles maintain heat resistance at 100°C or higher.

Inventive Principle:
Principle #40Composite materials

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 can be easily styled and recovered to their original form, exhibit enhanced heat resistance, self-extinguishing capabilities, and a glossy appearance, addressing user customization and safety concerns.

Implementation Method 1

the fiber has a modulus of elasticity of 500 to 15000 N/mm2

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

artificial hair fiber having superior shape altering characteristics and shape recovering characteristics

Methodology Applied
Scientific EffectShape memory: Shape Memory Polymer

Implementation Method 3

superior self-extinguishing characteristics and dripping-resistant characteristics

Methodology Applied
Scientific EffectFlame resistance: Combustion

Data Source

PatentUS9756886B2Artificial hair fiber having shape memory and shape restoration function, artificial hair fiber having excellent flame resistance, and artificial hair fiber having low gloss appearance
Publication Date: 2017.09.12 DENKA CO LTD

AI summary

Artificial hair fiber having shape memory and shape restoration function, artificial hair fiber having excellent flame resistance, and artificial hair fiber having low gloss appearance are provided.Provided is an artificial hair fiber including a resin composition including at least one polyamide, the artificial hair fiber satisfying at least one of constitutions (1) to (3): (1) the fiber has a modulus of elasticity of 2400 to 3000 N/mm2; (2) the polyamide has a weight average molecular weight Mw of 6.5×104 to 15×104 and the fiber has a modulus of elasticity of 500 to 15000 N/mm2; (3) the fiber has a modulus of elasticity of 500 to 15000 N/mm2 and the resin composition contains 5 to 20 parts by mass of fine particles with respect to 100 parts by mass of the polyamide.