Bi-component Spandex Yarn with Sheath Release Agent

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Solution Overview

Problem

Spandex elastomeric yarns face issues with high tack and friction, leading to filament breakage and non-uniformities in textiles due to excessive tension during processing, and the production of monofilament spandex yarns is economically challenging due to low asset utilization.

Innovation Solution

A bi-component spandex yarn with a sheath-core structure, where the sheath includes a release agent like mica or talc to prevent filament coalescence, allowing for robust separation and reduced friction, enabling efficient production of monofilament yarns with enhanced stretch and recovery properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If spandex filaments are bound together during spinning by pneumatic or mechanical twisting mechanisms, then inter-filament adhesion is improved, but friction and tackiness increase leading to filament breakage

Engineering Contradiction:
Improveinter-filament adhesionVSAvoidfriction and tackiness
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the harmful binding mechanism (pneumatic or mechanical twisting) that causes excessive friction and tackiness. Instead of binding filaments together, the invention allows filaments to remain separate and unbound, eliminating the source of harmful friction while maintaining necessary structural integrity through alternative means.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a lubricating agent as an intermediary substance that reduces friction between filaments. This mediator allows filaments to slide past each other with minimal resistance, eliminating the harmful friction effect without requiring mechanical binding, thus resolving the contradiction between adhesion and friction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If monofilament spandex yarns are produced, then fabric sheerness and low elastic power are improved, but production costs increase due to low asset utilization

Engineering Contradiction:
Improvefabric sheernessVSAvoidasset utilization
Core Design Contradiction:
ShapeVSProductivity

Solution Approach 1:

The patent segments the yarn structure into multiple separate filaments within a single yarn package, creating a multifilament construction that maintains the sheerness and low elastic power characteristics of monofilament yarns while enabling more efficient asset utilization through consolidated processing and reduced production costs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a universal yarn structure that combines the advantages of both monofilament and multifilament constructions. The lubricated filament structure allows the yarn to function as a single unit for fabric production while enabling separate filament extraction when needed, thus achieving multi-functionality and improved asset utilization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of manufacture

If spandex filaments are wound onto a package, then yarn packaging is achieved, but excessive tension and rapid transient increases in tension occur during unwinding leading to broken filaments

Engineering Contradiction:
Improveyarn packagingVSAvoidfilament tensile strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent introduces a lubricating agent as an intermediary that reduces friction and tension during the unwinding process. This mediator allows filaments to be unwound with minimal resistance, preventing excessive tension and rapid transient increases in tension that would otherwise cause filament breakage, thus protecting strength while maintaining packaging efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies a lubricating coating beforehand to the filaments before packaging and unwinding. This pre-applied lubrication acts as a cushioning layer that prevents direct friction and tension spikes during unwinding, protecting the filaments from breakage while allowing efficient packaging and handling.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Ease of operation

If release agent is applied to prevent filament coalescence, then filament separability is improved, but friction reduction is enhanced

Engineering Contradiction:
Improvefilament separabilityVSAvoidfriction
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent uses a lubricating agent as an intermediary substance that simultaneously achieves two objectives: it prevents filament coalescence by reducing adhesion between filaments, and it reduces friction during handling and processing. This single intermediary substance resolves the contradiction by addressing both separability and friction reduction requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution results in high-uniformity, low-friction spandex yarns that are economically advantageous, allowing for multiple monofilament yarns to be combined into a single package, improving textile processing efficiency and reducing filament breakage, while maintaining excellent elastic properties.

Implementation Method 1

the sheath includes a release agent, such as a characteristic crystalline material which shears into thin, flat platelets which readily fracture

Methodology Applied
Scientific EffectFriction reduction: Lubrication

Implementation Method 2

surface modification of the fiber prevents coalescence of the individual filaments forming the yarn due to fusion, adhesion, entangling or plying

Methodology Applied
Scientific EffectAdhesion prevention: Adhesive

Implementation Method 3

a characteristic crystalline material which shears into thin, flat platelets which readily fracture

Methodology Applied
Scientific EffectShearing: Fracture Mechanics

Implementation Method 4

Segmented polyurethane-urea elastic fibers having enhanced functionality and commercial value via a sheath-core bi-component construction

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 5

The polyurea-polyurethanes are prepared by methods known in the art... the prepolymer is extended in a second step with bi-functional alcohols or amines to form the final polymer

Methodology Applied
Scientific EffectPolymer deformation: Deformation

Data Source

PatentEP2659038B1Bi-component spandex with separable reduced friction filaments
Publication Date: 2019.07.17 INVISTA TECHNOLOGIES SARL(CH)
  • EP2659038B1 patent drawingFigure 1
  • EP2659038B1 patent drawingFigure 2
  • EP2659038B1 patent drawingFigure 3

AI summary

Disclosed herein are spandex fibers having reduced friction combined to provide a multiple end spandex package. The spandex fibers have a sheath-core cross-section with a lubricating additive is included in the sheath. A fusing additive specifically excluded to avoid coalescence among the individual filaments in the yarn. When combined in a yarn package, the multiple filaments are separable.