Optical Profilometry for Tubular Package Weld Bead Inspection

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Solution Overview

Problem

High-speed packaging lines for sterile cosmetic products in tubular packaging face challenges in reliably detecting sealing defects in the welded end without slowing production, as existing methods fail to accurately identify defects on a high-speed line, leading to potential contamination and product preservation issues.

Innovation Solution

A method involving optical profilometers to measure the thickness of the welded end's heel, which is smooth and predictable, allowing for non-destructive detection of defects, with a control system to eject defective tubes and alert operators, maintaining production rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the seal is placed flush with the product level to minimize air entrapment, then product preservation is improved, but the risk of product contamination of the welded interfaces increases

Engineering Contradiction:
Improveproduct preservationVSAvoidproduct contamination of welded interfaces
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by performing a first weld as close as possible to the tube's contents, then subsequently welding the upper section. This sequential welding approach allows the first weld to be positioned optimally for product preservation while the second weld creates a protected sealing surface, preventing product contamination of welded interfaces.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If existing inspection methods are used to detect welding defects, then defect detection capability is improved, but the packaging line must be stopped for inspection

Engineering Contradiction:
Improvedefect detection capabilityVSAvoidpackaging line speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent implements continuity of useful action by using optical profilometers that continuously measure the welded end of tubes as they pass through the packaging line. The non-contact optical measurement system operates without stopping the production line, maintaining both high defect detection precision and continuous packaging productivity.

Inventive Principle:
Principle #20Continuity of useful action

3Object-affected harmful factors

If the welded end is positioned higher above the fill level to avoid contamination, then product contamination risk is reduced, but the seal quality deteriorates due to increased air entrapment

Engineering Contradiction:
Improveproduct contamination riskVSAvoidseal quality
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies segmentation by dividing the welding process into two separate welding operations: a first weld positioned close to the product level for optimal sealing, and a second weld positioned higher to create a protected surface. This segmentation allows each weld to serve different functions, resolving the contradiction between contamination risk and seal quality.

Inventive Principle:
Principle #1Segmentation

4Measurement precision

If optical profilometers are used to measure the welded end, then non-destructive detection capability is improved, but the complexity of the inspection system increases

Engineering Contradiction:
Improvenon-destructive detection capabilityVSAvoidinspection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical contact-based inspection methods with optical profilometry technology. The optical system uses light to non-contactly measure the geometry of the welded end, eliminating the need for physical contact and complex mechanical measurement apparatus, thereby achieving high measurement precision with reduced system complexity.

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

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 immediate, non-destructive detection of sealing defects, preventing contamination and ensuring product preservation by automatically rejecting defective tubes and maintaining high production rates.

Implementation Method 1

The control device includes two optical profilometers arranged one opposite the other on either side of the conveying direction of the tubes

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3292942B1Method of closing of a tubular packaging and of continuously monitoring of the sealing of its extremity being welded after its filling
Publication Date: 2020.06.17 PIERRE FABRE DERMO COSMETIQUE SA
  • EP3292942B1 patent drawingFigure 1~6
  • EP3292942B1 patent drawingFigure 3~4
  • EP3292942B1 patent drawingFigure 5

AI summary

This application describes a method for checking the leak-tightness of the welded end of a tubular package (100a, 100b) after it has been filled, in particular with a sterile product. The method comprises the steps of first welding the end of the tube after pinching its lips to create a smooth bead (611), and then measuring the thickness of said bead. This application also relates to a device for carrying out such a method.