Optical Lamination Quality Assessment for Plastic Cards

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Solution Overview

Problem

Current methods for determining the lamination quality of plastic film layers in plastic card bodies are destructive, time-consuming, and prone to variability due to manual skill, failing to non-destructively assess the laminated state effectively.

Innovation Solution

A method and device utilizing measuring light sources and detectors to determine optical measurement parameters such as transmission and reflection, comparing these parameters to reference values to assess lamination quality without damaging the plastic card body, allowing for non-destructive evaluation of lamination quality and interfacial strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a delamination test is used to determine lamination quality, then the lamination quality can be assessed, but the test destroys the laminated object and is time-consuming

Engineering Contradiction:
Improvelamination quality assessmentVSAvoidtest duration
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical delamination test with an optical measurement system. Light sources illuminate the laminated plastic film layers from the front, and detectors measure optical parameters (transmittance, reflectance, haze) from the rear. This optical system eliminates the need for manual mechanical separation, enabling non-destructive and automated quality assessment.

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

Solution Approach 2:

The patent creates an optical copy or representation of the lamination quality through measured optical parameters. Instead of physically separating layers to assess quality, the system captures optical characteristics (light transmission, reflection patterns) that correlate with lamination quality, providing an indirect but accurate assessment method.

Inventive Principle:
Principle #26Copying

2Measurement precision

If a delamination test is used to determine lamination quality, then the lamination quality can be assessed, but the result depends on the tester's manual dexterity leading to variations in accuracy

Engineering Contradiction:
Improvelamination quality assessmentVSAvoidmeasurement consistency
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the manual mechanical delamination test with an automated optical measurement system. Light sources and detectors are positioned to automatically measure optical parameters without human intervention. The evaluation unit processes the optical data to determine lamination quality, eliminating variability caused by different testers' manual dexterity and ensuring consistent, reliable results.

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

Solution Approach 2:

The measurement system is self-contained and automated. The light sources, detectors, and evaluation unit work together as an integrated system that automatically performs measurement and assessment without requiring operator skill or manual dexterity. The system serves itself by automatically correlating optical parameters with lamination quality.

Inventive Principle:
Principle #25Self-service

3Productivity

If optical measurement is used to determine lamination quality non-destructively, then the object is preserved and automation is enabled, but the device complexity increases

Engineering Contradiction:
Improveautomated quality assessmentVSAvoidmeasurement system structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the measurement system into distinct functional segments: light sources positioned on the front side, detectors positioned on the rear side, and an evaluation unit for data processing. This segmentation allows each component to be optimized independently and simplifies the overall system architecture, making the complex optical measurement process manageable and implementable.

Inventive Principle:
Principle #1Segmentation

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

Enables the non-destructive determination of lamination quality, reducing waste and improving accuracy by identifying insufficiently or non-laminated areas, and providing a measure of autohesion and interfacial strength in plastic film layers.

Implementation Method 1

measuring light beams (7) incident on the layer arrangement (4) are generated by a measuring light source (6) and received by a detector device (8, 9). The corresponding measurement signals are fed to an evaluation unit (12), with which at least one optical measurement parameter is determined from the measurement signals, in particular a transmittance and/or a reflectance

Methodology Applied
Scientific EffectLight transmission and reflection: Reflection

Data Source

PatentEP3296721B1Method and device for the non destructive detection of a laminated condition of an arrangement of laminated plastic foil layers for a plastic card body
Publication Date: 2021.11.03 BUNDESDRUCKEREI GMBH
  • EP3296721B1 patent drawingFigure 1
  • EP3296721B1 patent drawingFigure 2~4
  • EP3296721B1 patent drawingFigure 5

AI summary

The disclosure relates to a method for non-destructively determining a laminated state of an arrangement (4) of laminated plastic film layers for a plastic card body, wherein the method comprises the following steps: optically determining a layer arrangement selected as a reference with stacked plastic film layers in the laminated state and optically determining a layer arrangement (4) to be tested with the stacked plastic film layers (2) in the laminated state, wherein, in the optical determination using measuring light beams (7), a transmittance is determined for each layer arrangement which is suitable to determine a lamination quality of the respective layer arrangement;The layer arrangement (4) to be tested is determined to be a usable plastic card body if the difference between the transmittance determined for the layer arrangement selected as a reference and the transmittance determined for the layer arrangement (4) to be tested lies within a predetermined tolerance limit for the transmittance. Furthermore, a device for non-destructively determining a laminated state of an arrangement (4) of laminated plastic film layers for a plastic card body is disclosed.