Longitudinal Seal Monitoring for High-Speed Packaging Lines

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing roll-fed packaging machines for liquid food products face high downtime and waste due to defects in the longitudinal seal, posing economic, environmental, and safety challenges.

Innovation Solution

A package seal control system using a fiber optic cable and data recording means to monitor and control the longitudinal seal, with a control unit adjusting heating and electricity to ensure quality, and a discarding device for defective packages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If continuous production at high speed is maintained, then productivity is improved, but the risk of defects and subsequent downtime increases

Engineering Contradiction:
Improveproduction speedVSAvoidseal quality consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback control system where a camera continuously monitors the longitudinal seal quality during high-speed production. The control unit receives images from the camera, analyzes seal quality using image processing algorithms, and automatically adjusts sealing parameters when defects are detected. This closed-loop feedback mechanism enables the system to maintain both high productivity and consistent seal quality by real-time correction of sealing parameters.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary detection of seal quality issues before they result in defective packages. By continuously monitoring the sealing process and detecting anomalies early, the control system can adjust parameters proactively to prevent defects, rather than reacting after packages are already compromised. This preliminary action approach maintains production continuity while ensuring quality.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If manual monitoring and adjustment of longitudinal seal is performed, then seal quality can be controlled, but downtime and labor resources increase

Engineering Contradiction:
Improveseal qualityVSAvoiddowntime
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The monitoring system operates autonomously without requiring manual intervention. The camera continuously captures seal images, the control unit automatically processes these images to detect defects, and the system self-adjusts sealing parameters when issues are detected. This self-service capability eliminates the need for manual monitoring and adjustment, reducing both labor resources and downtime while maintaining consistent seal quality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical monitoring and adjustment with an automated optical inspection system. Instead of operators visually inspecting seals and manually adjusting parameters, a camera-based image processing system performs detection and a control unit automatically modifies sealing parameters. This substitution of mechanical/manual processes with automated systems reduces downtime and labor while improving consistency.

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

3Productivity

If defects in longitudinal seal are not detected early, then production continues uninterrupted, but waste of finished product increases

Engineering Contradiction:
Improveproduction continuityVSAvoidproduct waste
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The system rapidly processes seal images and detects defects at high speed, allowing the production line to continue operating without interruption. By quickly identifying and flagging defective seals, the system enables selective discarding of only those packages with seal defects, rather than stopping production to inspect each package. This rapid defect identification minimizes product waste while maintaining production continuity.

Inventive Principle:
Principle #21Skipping (Rushing through)

Solution Approach 2:

The image processing system analyzes visual characteristics of the longitudinal seal, including color variations that indicate sealing quality issues. By detecting subtle color changes or visual anomalies in the seal area, the system can identify defective packages and trigger their discarding, thereby preventing defective products from entering the market while minimizing waste of good products.

Inventive Principle:
Principle #32Color changes

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

Minimizes downtime, reduces waste, and enhances product safety by ensuring consistent longitudinal seal quality.

Implementation Method 1

A package seal control system using a fiber optic cable and data recording means to monitor and control the longitudinal seal

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a heating device positioned downstream the longitudinal sealing device in a direction conforming to direction of flow of the packaging material

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3757554B1A method for monitoring and optionally controlling the longitudinal seal of a package material in a packaging and filling machine
Publication Date: 2026.02.25 TETRA LAVAL HOLDINGS & FINANCE SA
  • EP3757554B1 patent drawingFigure 1
  • EP3757554B1 patent drawingFigure 2
  • EP3757554B1 patent drawingFigure 3

AI summary

The present invention relates to a package seal control system (300), comprising a control unit (308), and data recording means (306) (e.g. camera) adapted to be communicatively connected to the control unit, wherein said data recording means (306) is adapted to monitor a longitudinal seal (302) extending in a direction conforming to a direction of flow of a packaging material (Tetra Pak) in a packaging and filling machine (100). The present invention further relates to its use and method for monitoring and optionally controlling the longitudinal seal (302) of a package material in a packaging and filling machine (100).