Quality, inspection and pack control

Machine Vision Inspection for Packaging Lines

Specify vision inspection for labels, codes, caps, fill level, seals and pack presence using defined defects, lighting, cameras, tracking and rejection.

Updated 1 September 2026Evidence-led production guidance7–10 minute read

Direct answer

Start with a defect library and measurable pass/fail rules. Control lighting, camera view, product position, speed and trigger, then prove detection using representative good, bad and borderline packs. Vision can inspect visible features but does not replace hidden seal-strength or contamination tests.

Why this matters

A camera system only performs as well as the inspection definition. “Check the label” must be translated into presence, identity, position, orientation, print, barcode and defect rules.

Decision table

InspectionTypical visible featureDesign requirement
LabelPresence, identity, position and skewFull label view and controlled product
CodeText, date, batch, barcode and readabilityResolution, contrast and stable print area
ClosurePresence, height, tilt and tamper featureMultiple views where geometry hides defects
Fill levelVisible level or headspaceControlled container and product optics
Seal areaVisible contamination or missing materialLighting and view of complete seal

Information to collect

  • Collect good, bad and borderline samples.
  • Define every defect with a measurement or example.
  • Record speed, spacing, rotation and presentation.
  • Assess reflections, colour and transparency.
  • Choose reject and reject-confirmation logic.
  • Plan recipe, access, audit images and data retention.

Practical method

  1. 1

    Prove lighting before increasing software complexity.

  2. 2

    Control the product through the imaging zone.

  3. 3

    Separate detection from tracking and rejection.

  4. 4

    Challenge every defect at every relevant position.

  5. 5

    Monitor false reject and missed defect rates.

Common mistakes to avoid

  • Training only on perfect samples.
  • Using uncontrolled ambient light.
  • Inspecting a curved pack from one unsuitable view.
  • Setting thresholds from too few samples.
  • Assuming a detected defect has been rejected.

Questions people also ask

What can machine vision inspect?

Visible features such as label, code, cap, fill level, colour, presence, position and some seal defects.

Can vision check seal integrity?

It can inspect visible seal contamination or geometry, but hidden leak strength normally requires another method.

What is a false reject?

A conforming pack classified as failed; false-reject rate should be measured alongside missed defects.

Does AI vision remove the need for samples?

No. Representative samples and an agreed defect definition remain essential for training and validation.

Relevant machinery routes

Continue from the requirement to the equipment

Use the specialist route that matches the product, pack and process. Final suitability requires representative samples, output targets and site information.

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