Knitted Raised Structures Through Differential Yarn Shrinkage

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Solution Overview

Problem

Conventional footwear uppers lack sufficient cushioning, rigidity, and durability while maintaining flexibility, and existing manufacturing methods are inefficient in creating complex textile structures.

Innovation Solution

A knitted component with raised structures, formed by varying yarn materials and applying heat to induce differential shrinkage, creating a multi-layered structure with defined ottomans or welts that provide cushioning and rigidity without sacrificing flexibility, using a weft-knitting process on a flat knitting machine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional weaving or interlooping processes are used to form textile uppers, then the manufacturing process is simple and well-established, but the resulting structure lacks sufficient cushioning, rigidity, and durability while maintaining flexibility

Engineering Contradiction:

Improvedurability and rigidityVSAvoidmanufacturing process complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The textile structure is segmented into multiple layers with different yarn types and properties. Each layer serves specific functions: some layers provide cushioning, others provide rigidity, and others maintain flexibility. This segmentation allows the composite structure to achieve superior overall performance that none of the individual layers could provide alone.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses composite yarns combining different materials (e.g., thermoplastic polymers with elastic fibers) within single yarns, and composites multiple yarn layers with different properties. This creates a textile structure that simultaneously achieves cushioning, rigidity, and durability while maintaining flexibility, resolving the contradiction between strength and manufacturing complexity.

Inventive Principle:

Principle #40Composite materials

2Shape

If heat treatment is applied to induce differential yarn shrinkage, then raised structures with cushioning and rigidity are formed, but the manufacturing process requires additional steps and precise temperature control

Engineering Contradiction:

Improveraised structure formationVSAvoidmanufacturing process simplicity

Core Design Contradiction:

ShapeVSEase of manufacture

Solution Approach 1:

The invention exploits parameter changes in yarn materials during heat treatment. By selecting yarns with different thermal shrinkage characteristics and exposing them to controlled heat, the process induces differential shrinkage that automatically forms the desired raised structures. This transforms a complex shaping operation into a materials-based solution that requires only temperature parameter control.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The heat treatment process utilizes phase transitions in thermoplastic polymer yarns. When heated above the glass transition or melting temperature, these yarns soften and shrink to different extents than non-thermoplastic yarns, creating the raised structures through controlled phase change rather than mechanical forming operations.

Inventive Principle:

Principle #36Phase transitions

3Device complexity

If multiple yarn materials with different shrinkage properties are used, then differential shrinkage creates complex multi-layered structures, but the material selection and process control become more difficult

Engineering Contradiction:

Improvetextile structure complexityVSAvoidshrinkage control precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

Different yarn materials with specific shrinkage properties are placed in specific locations within the textile structure where they are needed. Thermoplastic yarns are positioned in areas requiring raised structures, while other yarns are placed where flexibility or cushioning is prioritized. This local optimization allows complex structures to form through controlled differential shrinkage rather than requiring uniform material properties throughout.

Inventive Principle:

Principle #3Local quality

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 knitted component achieves enhanced cushioning, rigidity, and durability with improved aesthetic properties, while maintaining flexibility, through the use of thermoplastic polymer materials and differential yarn shrinkage.

Implementation Method 1

at least a portion of the upper may include one or more raised structures formed by differential yarn shrinkage upon exposure to a stimulus

Methodology Applied

Scientific EffectDifferential shrinkage: Thermal Contraction

Implementation Method 2

The third yarn may comprise a combination of a polyester yarn with an elastic core and a yarn formed of a thermoplastic polymer material

Methodology Applied

Scientific EffectPhase transition: Melting

Data Source

PatentUS12428759B2Knitted article with raised structure and methods of manufacture

Publication Date: 2025.09.30 NIKE INC

AI summary

A knitted article having a first layer and a second layer is described. The first layer is formed from a first yarn having a first shrinkage rate and the second layer is formed by a second yarn having a second shrinkage rate. The shrinkage rate of the first yarn is greater than the shrinkage rate of the second yarn when subjected to heat. Upon heat exposure, the second layer forms a raised structure. The raised structures have a length that is generally perpendicular to the lateral-to-medial course-wise direction of the knitted article.