Airbag Bladder Dyeing With Metal Complex Dyes for Colorfastness

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Solution Overview

Problem

Existing methods for coloring inflatable bladders, such as those used in athletic shoes, face challenges with dye migration and inefficiencies in the dyeing process, leading to uneven color application, waste, and poor colorfastness, especially with thermoplastic elastomers which have lower glass transition temperatures.

Innovation Solution

The use of metal complex dyes in a heated dyeing system with a solvent system comprising water and optional organic solvents, such as ethylene glycol phenyl ether, to immerse substrates like thermoplastic polyurethane and polyether block amides, facilitating dye diffusion and minimizing migration, while also reducing waste and labor costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If painting is used to color inflatable bladders, then color application is achieved, but the application is uneven and opaque, and the process is slow and labor intensive

Engineering Contradiction:
Improvecolor application uniformityVSAvoiddyeing process speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical painting process with a chemical diffusion process. Instead of mechanically applying paint to the surface, dye molecules diffuse through the thermoplastic elastomer material itself, achieving uniform color distribution throughout the material rather than just on the surface. This eliminates the uneven and opaque appearance associated with painting while maintaining efficient production speed.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the porous or semi-permeable nature of thermoplastic elastomer materials to allow dye molecules to diffuse through the material matrix. The cellular structure of the elastomer enables selective permeation of dye molecules, achieving uniform color distribution without compromising the material's functional properties. This diffusion-based approach resolves the contradiction between uniform color application and production efficiency.

Inventive Principle:
Principle #31Porous materials

2Reliability

If conventional dyes are used in thermoplastic elastomers, then color is achieved, but dye migration occurs leading to poor colorfastness

Engineering Contradiction:
ImprovecolorfastnessVSAvoiddye position stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical parameters of the dye molecules by selecting dyes with specific molecular weights, polarities, and functional groups that are compatible with thermoplastic elastomers. By matching the dye characteristics to the polymer matrix properties, the dye molecules become less mobile and more firmly embedded in the material, preventing migration while maintaining vibrant coloration and excellent colorfastness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite system where specifically selected dye molecules are integrated with the thermoplastic elastomer matrix. The combination of compatible dye and polymer creates a stable composite material where the dye is inherently restrained by molecular interactions with the polymer chains, eliminating the need for additional fixation mechanisms and ensuring long-term color stability.

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If colored sheets are used to produce colored bladders, then color is achieved, but waste from colored trim scrap is generated that must be recycled

Engineering Contradiction:
Improvecolor consistencyVSAvoidcolored trim scrap waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent extracts the colorant from separate colored material layers and directly incorporates it into the base thermoplastic elastomer material through diffusion. This eliminates the need for separate colored trim pieces or sheets, as the color is now an intrinsic property of the material itself. The approach removes the source of colored trim scrap waste while maintaining consistent color throughout the product.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the coloring function with the base material by diffusing dye molecules throughout the thermoplastic elastomer. Instead of combining colored trim pieces with uncolored material, the entire material becomes uniformly colored through molecular diffusion. This integration eliminates the interface between colored and uncolored materials that generates trim scrap, achieving both color consistency and waste reduction.

Inventive Principle:
Principle #5Merging (Combining)

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 process achieves effective colorfastness and transparency with reduced dye migration, providing a cost-effective and efficient method for producing colored inflatable bladders with improved visual appearance and adherence to lean manufacturing principles.

Implementation Method 1

immersing the substrate in a heated dyeing system for a time sufficient to allow an amount of dye to diffuse into the substrate

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

heated dyeing system

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentUS7611547B2Airbag dyeing compositions and processes
Publication Date: 2009.11.03 NIKE INC

AI summary

A process for dyeing a thermoplastic elastomeric substrate comprising immersing the substrate into a dye system comprising at least one metal complex dye and a solvent system comprising water and an organic solvent. The organic solvent may be soluble, partially miscible with water or insoluble or nearly insoluble in water. In particular, the substrate is an inflated bladder such as an airbag used in athletic shoes.