Foil Welding Elongation Device for Tubular Parts

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Solution Overview

Problem

Conventional film welding processes in commercial production plants often result in film stretching, poor sealing, pinching, wrinkling, and suboptimal strength due to the mechanical stress of wrapping films around three-dimensional connection parts, leading to elongation issues and suboptimal weld quality.

Innovation Solution

An elongation device is used to extend the film outside the connection area, providing a length reserve that allows the film to elongate without significant tensile forces, using a deforming tool to create a corrugated or wavy shape, which can be heated to facilitate deformation, ensuring smooth transitions and controlled elongation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the film is wrapped around the three-dimensional connection part during conventional welding, then the connection part is securely attached to the foil, but the film undergoes strong mechanical stress causing stretching, pinching, and wrinkling that compromises weld quality

Engineering Contradiction:
Improveweld strengthVSAvoidweld quality
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The invention applies preliminary action by extending the film length before the welding process. An extension device creates additional length reserve in the film web prior to wrapping it around the connection part, allowing the film to accommodate the three-dimensional shape without excessive tensile stress during welding, thereby preventing pinching and wrinkling while maintaining secure attachment

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the film is held at the edge by transport devices during welding, then the film can be positioned and transported, but the film cannot elongate smoothly causing stretching and poor sealing

Engineering Contradiction:
Improvefilm positioningVSAvoidsealing quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The extension device performs preliminary action by creating length reserve in the film before the welding and sealing operations. This pre-extension allows the film to flow smoothly around the connection part without being constrained by edge-holding transport devices, ensuring both ease of positioning and reliable sealing

Inventive Principle:
Principle #10Preliminary action

3Shape

If the connection part development length is longer than the direct connection path, then the film can wrap around the three-dimensional shape, but the film must be forcibly lengthened causing stress and suboptimal weld strength

Engineering Contradiction:
Improveconnection part geometryVSAvoidfilm strength adjacent to weld
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The extension device applies preliminary action by pre-lengthening the film in a controlled manner before the wrapping process. This creates a length reserve that allows the film to accommodate the extended development path of the three-dimensional connection part without excessive tensile stress, preventing film stretching and maintaining optimal strength adjacent to the weld area

Inventive Principle:
Principle #10Preliminary 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 approach significantly reduces mechanical stress during welding, achieving excellent welding results with improved film strength and sealing quality by allowing the film to draw on the extended length reserve during wrapping around connection parts.

Implementation Method 1

using a deforming tool to create a corrugated or wavy shape

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

which can be heated to facilitate deformation

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2323832B1Apparatus for welding a joining region of a foil to a connecting part and use, method, system and bag
Publication Date: 2016.10.12 KIEFEL GMBH
  • EP2323832B1 patent drawingFigure 1~4
  • EP2323832B1 patent drawingFigure 5~7

AI summary

The invention relates to an apparatus for welding a joining region of a foil to a connecting part, particularly two foils to a tubular connecting part. Conventional apparatuses are associated with the risk of steep workpiece flanges causing uncontrolled weaknesses in the foil and the weld seam. According to the invention, an extension of the foil outside of the joining region is provided in a controlled manner such that the foil has spare length. In this connection, the invention further relates to the use of a foil, to a method for welding, to a system for producing bag, and to a bag.