Automatic Control of Plastic Bag Handles Using Optical Inspection

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Solution Overview

Problem

High-speed plastic bag production lines face challenges in quality control due to inconsistent handle width and scrap removal, leading to production inefficiencies and quality issues when using automatic boxing systems, as human intervention is necessary for accurate monitoring.

Innovation Solution

An automatic control system employing a video camera and image processing to measure handle width and detect scrap presence, combined with a guide system to reduce film shifting, enabling precise quality control and efficient automatic boxing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If automatic boxing systems are used to increase production speed, then productivity is improved, but quality control deteriorates because only sample checking is possible

Engineering Contradiction:
Improveproduction speedVSAvoidquality control
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces manual visual inspection with an automated optical inspection system using a video camera and image processing unit. The camera captures images of the bag handles, and the image processing system automatically analyzes them to detect width variations and scrap presence, enabling continuous quality control at high production speeds without relying on manual sampling

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

Solution Approach 2:

The inspection system provides real-time feedback by continuously monitoring each bag handle as it passes through the production line. The system immediately detects defects and can trigger alerts or automatic rejection mechanisms, creating a closed-loop quality control system that maintains reliability while operating at high productivity levels

Inventive Principle:
Principle #23Feedback

2Productivity

If film processing speed is increased to improve productivity, then production capacity is improved, but manufacturing precision deteriorates due to film slipping and handle width variation

Engineering Contradiction:
Improveproduction capacityVSAvoidhandle width consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements a guide system that positions and stabilizes the film web before it enters the handle-cutting operation. This preliminary positioning action prevents film slipping during high-speed processing, ensuring that handles are cut at consistent widths even when production speed is increased

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses an automated optical measurement system to continuously monitor handle width dimensions. This electronic measurement and control system replaces manual measurement methods, enabling precise detection of width variations and providing feedback to maintain manufacturing precision at high production speeds

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

3Manufacturing precision

If manual inspection is used to maintain quality control, then manufacturing precision is improved, but productivity deteriorates due to operator limitations

Engineering Contradiction:
Improvequality monitoring accuracyVSAvoidproduction speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces the human operator's visual inspection capability with an automated video camera and image processing system. This electronic inspection system can continuously monitor all bags at high speed without fatigue or distraction, maintaining high detection accuracy while enabling much faster production rates than manual inspection

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

Solution Approach 2:

The inspection system is fully automated and self-operating, requiring no human intervention for each bag inspection. The system autonomously captures images, processes them, detects defects, and records results, enabling continuous operation at high speeds without the limitations of manual inspection

Inventive Principle:
Principle #25Self-service

4Manufacturing precision

If die cutting blade depth is increased to remove scrap completely, then manufacturing precision is improved, but device complexity increases due to wear and adjustment requirements

Engineering Contradiction:
Improvescrap removal completenessVSAvoidblade maintenance complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements an automated inspection system that provides continuous feedback on scrap removal effectiveness. The system detects the presence of remaining scrap and handle width variations, enabling automatic adjustment or alerting mechanisms that maintain optimal cutting depth without requiring frequent manual intervention or complex maintenance procedures

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual blade depth adjustment and inspection with an automated optical measurement and control system. This electronic system continuously monitors cutting quality and can automatically adjust parameters or trigger maintenance alerts, reducing the complexity of blade maintenance while ensuring complete scrap removal

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

Ensures constant monitoring and reduction of waste by allowing automatic boxing with precise quality control, saving time and production costs while maintaining product consistency.

Implementation Method 1

a video camera adapted to capture the image of the stack of bags in the portion of the handles

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

an image processing system which converts the pixels acquired by the video camera into geometric outlines of the handles

Methodology Applied
Scientific EffectImage Processing: Image Processing

Data Source

PatentEP1816431B1Device and method for automatic control of plastic bag handles
Publication Date: 2016.03.09 MOBERT SRL
  • EP1816431B1 patent drawingFigure 1
  • EP1816431B1 patent drawingFigure 2
  • EP1816431B1 patent drawingFigure 3~4

AI summary

An automatic control system (3) for the handles (B) of plastic bags disposed in stacks (M) is described, comprising a video camera (30) adapted to capture the image of the stack (M) of bags in the position of the handles (B) and an image processing system which converts the pixels acquired by the video camera (3) into geometric outlines of the handles which can thus be measured to see if the handles (B) of said stack come within the pre-set range of tolerance. The control device (3) further checks that die cutting has taken place correctly, that is, that the entire scrap, which may have remained attached at a single point, has been removed. The control device (3) further employs a system of side guides (80) for the film (P) placed in the sealing unit (100) for formation of the bags, adapted to reduce lateral shifting of the film (P) during processing, thus reducing the final waste of product due to out-of-range handles (B).