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AI Visual Inspection Equipment for Footwear Materials

Footwear material AI visual inspection equipment: for footwear components such as flyknit uppers, mesh uppers, shoe quarters, tongues, insoles and EVA midsoles, it inspects yarn breakage, fuzz, color differences, damage, flash and printed logo defects, and outputs OK/NG.

Products Overview

Flyknit uppers have complex textures, making them the most difficult category in footwear material inspection

Quick answers

Footwear material AI visual inspection equipment is used to inspect flyknit uppers, mesh fabric uppers, quarters, tongues, insoles, and EVA midsoles. With industrial cameras and custom lighting it identifies yarn breakage, fuzz, color differences, damage, flash, and printed mark defects, outputs OK/NG, and interlocks with the production line.

The inspection difficulty for footwear materials centers on Upper: Flyknit uppers are formed by knitted yarn, and the texture itself is a complex pattern, so defects such as yarn breakage, dropped stitches and yarn misalignment have very low contrast against the patterned background.

By comparison, inspection of EVA midsoles and soles is closer to routine injection molded parts: defects such as flash, short shot, color difference, and indentation have relatively clear forms.

Therefore footwear material inspection is usually designed part by part: uppers focus on fine weaving defects, while soles and midsoles focus on injection molding and foaming defects.

  • Covered components: flyknit uppers, mesh uppers, shoe quarters, tongues, insoles, and EVA midsoles
  • Challenging parts: yarn breakage and dropped stitches in flyknit uppers
  • Common Components: Injection Molding and Foaming Defects in EVA Midsoles and Outsoles
  • Solution strategy: inspection items and algorithms configured separately by component

Core Functions

What the Equipment Can Do and How Far It Can Go

Flyknit Upper Inspection

For woven structures, it identifies yarn breakage, dropped stitches, yarn misalignment, and uneven weaving.

Mesh Fabric Inspection

Inspection of holes, weaving defects, and color difference in mesh fabric.

Sole and Midsole Inspection

Flash, short shot, color difference, and indentation on EVA foam parts.

Print Mark and Decoration Inspection

Position, clarity and completeness of the Logo and printed marks.

Outline Contour Measurement

Dimension check of upper shape and insole contour.

Per-component Configuration

Different components use different light sources and algorithm recipes.

inspection Object

Flyknit UpperMesh Fabric UpperShoe quarterTongueInsoleEVA midsoleTPU footwear materialUpper Cut Pieces

Shoe Uppers

Flyknit, mesh fabric and knitted uppers, with the focus on weaving defects

Midsole and Outsole

EVA and TPU foam parts, with the focus on injection molding and foaming defects

Lining and Insole

Appearance and contour inspection of insoles and linings

Decoration and Printed Marking

Quality check of logos, printed marks, and heat-pressed decorations

inspection defect

Defect TypesTypical ComponentsInspection Focus Points
Yarn Breakage / Dropped StitchFlyknit UpperLow contrast against patterned backgrounds, requiring dedicated illumination
Fuzz / Floating YarnShoe Uppers, Mesh FabricDistinguished from normal fuzz
color difference Shoe Uppers, SolesRequires a stable light source datum
Damage / HoleMesh Fabric, Shoe UppersTransmitted-light imaging is more direct
Flash / BurrEVA midsoleContour edge extraction
Short Shot / Sink MarkEVA midsoleRegular shape; contour and grayscale can be combined
Printed Marking DefectsShoe Uppers, InsolesPosition, clarity and completeness
Yarn breakage inspection on Flyknit uppers is a relatively difficult project; we recommend a small batch feasibility validation first to confirm whether it can be distinguished reliably against the patterned background.

Working Principles

Visual inspection judgement chainThe complete chain from image acquisition to OK/NG judgement and PLC interlocking.image acquisitiontrigger captureTarget Positioningtemplate matchingfeature recognitionAlgorithm JudgementResult JudgementOK / NGindustrial communicationPLC interlockingRelease OKRejection / NG AlarmEvery step's result retains the image and judgement item, for traceability and review
Inspection Judgement Chain — Acquisition → Positioning → Recognition → Judgment → Communication interlocking; the entire chain runs locally on the machine.
  • 01 Footwear component loading
  • 02 Positioning and Fixing
  • 03 Dedicated illumination imaging
  • 04 Weaving defect inspection
  • 05 Injection molding and foaming defect inspection
  • 06 Print mark and contour inspection
  • 07 Result Composition OK / NG
  • 08 NG rejection
  • 09 Data Recording

Relationship Between Imaging and Judgement

The key to flyknit upper inspection is Separating "Pattern" from "Defect". Because the upper pattern itself is a complex gray-level variation, an absolute threshold will definitely produce many false calls. A workable path is to let the algorithm learn the normal distribution characteristics of the pattern and judge significant deviations as defects.

Vision System

How Cameras, Lenses, Light Sources and Controllers Are Configured

industrial camera

Select area-scan or line-scan by field of view and minimum defect size; continuous web materials usually use line-scan cameras

  • Area-scan camera: fixed-shot, single-piece and intermittent feed applications
  • Line-scan camera: for continuous material travel, wide areas, and even-interval imaging
  • Pixel equivalent is derived backwards from "minimum resolvable defect ÷ desired pixel count", rather than fixing the camera first

lens

Determines field of view, distortion, and depth of field; precision measurement requires telecentric lenses

  • Standard industrial lens: low cost, suitable for appearance inspection
  • Low-distortion lens: for large-format applications where the edges must also be judged
  • Telecentric lens: suitable for hole diameter, contour and dimensional measurement
  • Depth of field must match material waviness and fixture repeat positioning accuracy

Light Source and Illumination

Whether defects in flexible materials can be captured depends largely on the lighting

  • Diffuse light: uniform illumination, suitable for color difference and stain applications
  • Low-angle light: highlights scratches, indentations, wrinkles and other surface relief
  • Backlight/transmitted light: highlights holes, damage and short shot
  • Coaxial light / stripe light: suppresses reflection, suitable for coated or highly reflective surfaces

Controllers and Industrial PCs

The platform for running algorithms, outputting results and interlocking with the production line

  • An industrial computer or vision controller runs the algorithms
  • A light source controller handles brightness adjustment and strobe synchronization
  • Interacts with the PLC to complete interlocking, alarming, and rejection

AI algorithm

Choose the Algorithm by Defect Form, Not by Complexity

Template Matching and Positioning

Locate first, then judge. Every defect judgment is built on a stable coordinate system.

  • Shape matching / gray-scale matching: good stability, suitable for fixed stations
  • Align first, then split the regions, to avoid false calls caused by position drift

Blob and Morphological Analysis

Suited to defects such as stains, holes and foreign matter that show a clear grayscale/color difference from the background

  • Threshold segmentation → connected component statistics → judgement by area / aspect ratio / circularity
  • High requirements on illumination stability; the light source must work with the fixture

Edge and Contour Measurement

Suitable for dimension, contour, hole position and spacing judgements

  • Sub-pixel edge extraction to obtain a contour point set
  • Fit lines/circles/arcs and calculate length, diameter, angle and position tolerance

Deep Learning (Classification / Detection / Segmentation)

Suited to defects such as scratches, wrinkles and skipped stitches, whose shapes vary and are hard to describe with rules

  • When defect forms are irregular, it is difficult for rule-based algorithms to enumerate them all
  • Requires OK / NG sample training; sample quantity and coverage determine the upper limit
  • Enables pixel-level segmentation and outputs defect length, width, area and position

Automatic Alarm and rejection

How inspection results act on the production line

Inspection results are not only shown on a screen. Workpieces judged NG need to be Mark the position and interlock rejection or sorting, and archives the image and judgement result for that part for later traceability and re-judgement.

The alarm method is set according to site practice: audible and visual alarm, on-screen pop-up, PLC set bit, or all three at once. Critical defects and general defects can use different handling strategies — the former stops the machine and alarms, the latter is only marked.

  • 01 image acquisition
  • 02 Positioning and region segmentation
  • 03 Defect Judgement
  • 04 Combine results into a single OK / NG per piece
  • 05 Result sent to PLC
  • 06 NG Rejection / Sorting
  • 07 Image and data archiving

data traceability

Records, Queries and Quality Closed Loop

Per-Piece Records

The judgment result, defect type, defect position and timestamp of every part are written to the database

  • Supports retrieval by time, batch and defect type
  • NG image retention for re-judgement

Batch and Recipe

Different products use different recipes, called up at changeover to reduce manual parameter tuning

  • Recipes store the inspection region, thresholds and algorithm parameters

Production Line Data Integration

Exchange inspection data with the MES / host system

  • Output pass rate, defect distribution and other statistics
  • The interface method depends on the site system

equipment configuration

Optional Configuration Items and Selection Logic

Configuration ItemDescription
Applicable ComponentsFlyknit Uppers / Mesh Fabric Uppers / Shoe Quarters / Tongues / Insoles / EVA Midsoles
Inspection MethodDedicated lighting + industrial camera + AI algorithm
Changeover MethodRecipe Switching
Inspection SpeedTo be added
inspection accuracyTo be added
communication methodI/O · TCP · RS485 · Modbus · S7 · Profinet
Enclosure and Power SupplyTo Be Confirmed on Site
To be added —— cycle time, lower limit of detectable defect size, number of styles and overall dimensions must be confirmed according to the actual product.

Application Industry

Which Industry This Equipment Is Usually Installed In

The above is the equipment Common applicable industries, and the specific feasibility depends on the inspection object and site conditions, subject to the results of a measured sample trial.

Applicable Materials

Detectable Material Types

knitted fabric mesh fabric PU synthetic leather EVAfoam TPU Laminated Fabric

Common Question

Can yarn breakage in flyknit uppers be detected reliably?
This is a fairly difficult project. Because the upper itself has a complex pattern, yarn breakage has limited contrast against the patterned background. A workable path is to use deep learning to learn the normal weave structure and judge anomalies as defects, but how stable this is must be confirmed by measured small-batch samples.
Is EVA Midsole Inspection Difficult?
Relatively easy. Defects in EVA midsoles (flash, short shot, color difference, indentation) have clear forms and fall within the scope of routine appearance inspection for injection molded and foamed parts.
Can Uppers and Soles Be Inspected on One Machine?
The hardware can be shared, but the light source solution and algorithm recipe must be configured separately. If the output of both part types is large, setting up separate stations is usually more efficient.
What If Footwear Material Colors and Styles Change Frequently?
This is exactly the value of recipe-based management. One set of parameters is saved for each style, and on changeover the corresponding recipe is simply recalled, with no need to retune the algorithm.
Can the inspection cycle time keep up with the production line?
To be added. Cycle time depends on part dimensions, the number of surfaces to be imaged and algorithm complexity. Upper parts usually take longer per piece than small parts and must be evaluated against your actual cycle time.
What Information Do You Need to Provide?
Recommended to provide: OK / NG samples of each component (upper, midsole, insole, etc.), material and process, quantitative defect criteria, number of styles and changeover frequency, and cycle time requirements.

Submit sample testing

Inspection of flyknit uppers requires physical validation. Please provide samples of different styles and defects, and we will first run small-batch imaging and judgement tests.

JPG / PNG supported, multiple files allowed
Each file must not exceed 20 MB
    JPG / PNG supported, multiple files allowed
    Each file must not exceed 20 MB
      JPG / PNG supported, multiple files allowed
      Each file must not exceed 20 MB
        A solution engineer will contact you within 1 business day after submission

        Need to assess imaging conditions, defect criteria and cycle time item by item? Go to the Full Requirement Assessment →

        Send Us Your Workpiece and We Will Show You the Measured Results

        Equipment configuration varies with the inspection object, field of view and cycle time. Provide OK and NG samples and we will run actual imaging and judgement tests and recommend the corresponding model and configuration.

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