Bag-Making Laser Welding Position Adjustment

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Solution Overview

Problem

Existing bag making apparatuses experience issues with unwelded parts due to the zipper cooling down before reaching the pressure rollers, leading to incomplete welding and material loss, which affects the quality and integrity of the bags.

Innovation Solution

A bag making apparatus with a movement device that adjusts the position of the pressure unit and laser unit relative to each other during the pause phase of the intermittent feed cycle, ensuring the zipper remains molten until welding, and includes sensors and control systems to detect and correct positional relationships for optimal welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sheet panel and zipper are intermittently fed through the pressure rollers, then the welding process can be controlled and regulated, but the irradiated part cools down during the pause phase and returns to non-molten state, causing unwelded parts to be generated

Engineering Contradiction:
Improvewelding qualityVSAvoidmaterial loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by moving the pressure unit and laser unit together upstream and downstream during the pause phase before the next feed cycle begins. This preliminary positioning ensures that when the sheet panel is fed again, the irradiated part is already in the correct position to be immediately welded without cooling down, thereby preventing unwelded parts while maintaining controlled intermittent feeding.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If the pressure unit and laser unit are fixed in position, then the device structure is simple, but the unwelded part position cannot be adjusted and causes leakage and material loss

Engineering Contradiction:
Improvedevice structureVSAvoidwelding consistency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies dynamics by making the pressure unit and laser unit movable relative to each other along the feed direction. During the pause phase, the movement device adjusts their positions together while maintaining the relative positional relationship between them. This dynamic adjustment allows the system to compensate for position variations and ensure consistent welding quality without generating unwelded parts, while the structure remains relatively simple.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the laser irradiation is applied continuously, then the zipper remains molten and welding is consistent, but the material temperature increases excessively causing deformation and energy waste

Engineering Contradiction:
Improvewelding consistencyVSAvoidmaterial temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent applies periodic action by using intermittent feeding combined with coordinated movement of the pressure unit and laser unit during pause phases. The laser irradiation is applied periodically during feed phases when the material needs to be melted, and the units are moved during pause phases to maintain positioning without continuous irradiation. This periodic operation ensures consistent welding while preventing excessive temperature accumulation and material deformation.

Inventive Principle:
Principle #19Periodic action

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

This solution ensures consistent welding by maintaining the molten state of the zipper material, reducing unwelded areas and improving bag quality by adjusting the position of the pressure and laser units, thereby minimizing material loss and leakage.

Implementation Method 1

a laser unit configured to irradiate the sheet panel or the strip member with a laser beam at an irradiation position upstream away of a pressure position of the pressure unit to melt the sheet panel or the strip member using the laser beam

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

a pressure unit comprising a pair of pressure rollers for pressurizing the sheet panel and the strip member superposed on each other during a feed phase of an intermittent feed cycle

Methodology Applied
Scientific EffectPressure welding: Pressure Increase

Data Source

PatentEP4219140B1Bag-making machine
Publication Date: 2024.12.25 TOTANI CORP (JP)
  • EP4219140B1 patent drawingFigure 1A~1C
  • EP4219140B1 patent drawingFigure 2A~2B
  • EP4219140B1 patent drawingFigure 3

AI summary

This bag-making machine comprises a welding device for welding a body material and a strip-shaped member to each other during an interval in which the body material is intermittently fed by a feeding device, and a cutting device which is provided downstream from the welding device and which cross-cuts the body material and the strip-shaped member at each intermittent feeding. The welding device comprises a pressing unit for pressing the body material and the strip-shaped member in a state in which the body material and the strip-shaped member are superposed on each other, and a laser unit for radiating a laser beam to the body material or the strip-shaped member further upstream than the pressing position of the pressing unit to melt the body material or the strip-shaped member. The pressing unit and the laser unit are configured to be able to move integrally upstream and downstream with respect to the body material with the relative positional relationship of the pressing position of the pressing unit and the irradiation position of the laser unit maintained.