Seamless Knitted Footwear Upper with Variable Thickness Zones
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Solution Overview
Problem
Current footwear with knitted uppers face issues such as delicacy, wear, poor protection against impacts, low breathability, and easy deformation, particularly due to constant fabric thickness not accommodating varying grip and resistance needs across the foot, and the presence of seams that can irritate the foot over time.
Innovation Solution
A one-piece, machine-finished footwear upper with differentiated thicknesses and interwoven sections, produced using a knitting machine, featuring alternating zones for breathability, support, and varying degrees of padding, without seams or raw edges, utilizing a core and external layers of knitted fabric with varying yarn thicknesses and machining to provide customized grip, protection, and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a knitted fabric upper is used to provide comfort and flexibility, then comfort and flexibility are improved, but protection against impacts and resistance to wear deteriorate
Solution Approach 1:
The patent applies local quality by varying the fabric thickness and knit structure in different zones of the footwear upper. Specific zones receive reinforced knitting with higher thread density and thicker yarns to provide impact protection, while other zones maintain thinner, more flexible structures for comfort. This spatial variation of material properties resolves the contradiction between comfort and protection.
Solution Approach 2:
The patent uses composite materials by combining multiple yarn types with different properties within the same knitted structure. It integrates elastic yarns for flexibility, rigid yarns for structural support, and thermoplastic yarns for durability. This multi-material approach enables the upper to simultaneously provide comfort through elastic components and protection through rigid components.
2Ease of manufacture
If the fabric thickness is kept constant for simplicity of manufacture, then ease of manufacture is improved, but adaptability to different foot zones and protection requirements deteriorate
Solution Approach 1:
The patent implements local quality through programmed variations in fabric thickness and knit density across different zones of the upper. The knitting machine is controlled to produce regions with different thread counts, yarn thicknesses, and stitch patterns that correspond to specific anatomical features of the foot, such as the toe box, heel, and instep, thereby achieving adaptability while maintaining a single-integration manufacturing process.
Solution Approach 2:
The patent applies dynamics by creating a fabric structure that is inherently adaptive to foot movement and deformation. The knitted construction with its interlocking loops allows the material to dynamically adjust its properties under stress, providing zones that expand and contract with foot motion while maintaining structural integrity and protective functions.
3Strength
If seams are used to attach the upper to the sole and construct different zones, then structural integrity is improved, but comfort deteriorates due to irritation and pressure
Solution Approach 1:
The patent merges the upper construction into a single integrated knitted piece that is formed as one continuous structure. This seamless upper eliminates the need for traditional seams and stitching to join different zones or attach the upper to the sole, thereby maintaining structural integrity through the continuous knit while removing sources of irritation and pressure that would compromise comfort.
Solution Approach 2:
The patent employs the seamless knitted upper as a flexible shell that conforms to the foot's anatomy. The continuous knit structure acts as a thin film that provides structural support and protection without the rigid seams of traditional construction, allowing the material to flex and move with the foot while maintaining its integrity and protective functions.
4Strength
If a thin layer of leather is added to protect the yarns, then protection and durability are improved, but breathability deteriorates
Solution Approach 1:
The patent uses porous materials by incorporating an open-knit structure and breathable mesh zones within the upper construction. These porous regions allow air circulation and moisture vapor transmission while maintaining protective functions. The knit architecture itself creates controlled porosity that provides both protection and breathability without requiring additional non-breathable layers.
Data Source
AI summary
A footwear upper is made of a knitted engineered fabric. The footwear upper includes a front portion for covering an upper part of a foot, an intermediate portion corresponding to an insole, and a rear portion for covering a heel. The front portion, the intermediate portion and the rear portion are produced with an engineered fabric composed of an internal core and a pair of external layers of knitted fabric. The footwear upper is made as one piece, is already contoured during a machining stage and is ready to be applied to a sole without any other type of machining, except for the possibility of sealing for joining the front portion to the rear portion laterally.