Vacuum Cleaner Filter Bag Weld Seam Segmentation for Higher Tear Strength

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Solution Overview

Problem

Vacuum cleaner filter bags experience weak points at weld seams, leading to damage and uncontrolled dirt escape when filled with dirt particles, especially with nonwovens above 200 g/m2 or when connecting multiple layers, as existing welds fail to provide sufficient tear strength.

Innovation Solution

A vacuum cleaner filter bag with a weld seam featuring alternately welded and unwelded areas, where the unwelded areas are 1.0 mm to 5.0 mm long and the welded areas are 1.5 mm to 7.5 mm long, providing a higher tear strength without compromising tightness, and an ultrasonic welding system with a tool that produces these seams.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous linear weld seams are used to connect filter material layers, then the filter bag achieves sufficient tightness and closure, but the weld seams become permanent weak points that burst open under mechanical loads when the bag is highly filled with dirt particles

Engineering Contradiction:
Improvetightness of filter bagVSAvoidtear strength of weld seam
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The continuous weld seam is segmented into alternating welded and unwelded areas along its linear course. The welded areas (1.0-10.0 mm length) provide closure and tightness, while the unwelded areas (>1.0-5.0 mm length) act as stress relief zones that prevent catastrophic failure when the bag is filled with dirt particles, transforming the single continuous weak point into multiple distributed segments.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If ultrasonic welding is applied to nonwovens with mass per unit area above 200 g/m2 or when connecting more than two layers, then the filter bag achieves necessary structural integrity, but the weld seam fails to provide sufficient tear strength and the total mass per unit area exceeds 400 g/m2

Engineering Contradiction:
Improvestructural integrity of filter bagVSAvoidtear strength of weld seam
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The weld seam is divided into welded and unwelded segments that alternate along its length. This segmentation allows the structure to maintain integrity for heavy-duty applications (multiple layers, high mass per unit area) while the unwelded segments provide stress relief zones that prevent catastrophic tear propagation under load.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the weld seam have different properties: welded areas provide strong bonding and structural integrity for heavy-duty applications, while unwelded areas provide stress relief and prevent tear propagation. This local differentiation of properties allows the weld seam to simultaneously achieve both structural integrity and tear resistance.

Inventive Principle:
Principle #3Local quality

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

The solution significantly enhances the tear strength of the weld seam, preventing the filter bag from bursting open under mechanical loads while maintaining separation efficiency, with a preferred tearing force of at least 30 N, effectively addressing the weaknesses of previous welds.

Implementation Method 1

ultrasonic welding of nonwoven fabrics

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Implementation Method 2

weld seam in a vacuum cleaner filter bag made from thermally weldable materials

Methodology Applied
Scientific EffectThermal welding: Heating

Data Source

PatentEP3142537B1Vacuum cleaner filter bag with high-strength weld seam, method for its production, tool and ultrasonic welding device for producing an extremely strong weld seam
Publication Date: 2020.05.13 EUROLIFTERS HLDG NV
  • EP3142537B1 patent drawingFigure 1
  • EP3142537B1 patent drawingFigure 2~3
  • EP3142537B1 patent drawingFigure 4

AI summary

The invention relates to a vacuum cleaner filter bag composed of a thermally weldable filter material, which forms the closed off interior of the vacuum cleaner filter bag. The interior is closed at least on one side by means of a weld seam designed according to the invention, in the case of which weld seam at least two layers of the filter material are welded to each other. The weld seam designed according to the invention is characterized by a far higher tear strength in comparison with weld seams known from the prior art. The invention further relates to a method for producing the vacuum cleaner filter bag, to a tool for producing the high-strength weld seam, and to an ultrasonic welding system in which said tool is integrated.