Vacuum cleaner filter bag with improved weld seam strength

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Solution Overview

Problem

Existing vacuum cleaner filter bags made from recycled materials face challenges in achieving sufficient weld seam strength due to the inhomogeneous nature of the materials used, which affects the transmission of ultrasonic energy and the bonding process.

Innovation Solution

Incorporating an intermediate layer made of recycled polypropylene (rPP) nonwoven fabric as a main component between the support and fine filter layers, and potentially between the fine filter and capacity layers, acts as a welding agent to enhance the weld seam strength, eliminating the need for complex material strip positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If different recycled materials are used in the nonwoven laminate to achieve high sustainability, then the proportion of recycled plastics increases, but the weld seam strength decreases due to inhomogeneous material properties and poor ultrasonic energy transmission

Engineering Contradiction:
ImprovesustainabilityVSAvoidweld seam strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces an intermediate layer made of rPP nonwoven fabric between the support layer and fine filter layer. This intermediate layer acts as a mediator that improves ultrasonic energy transmission and facilitates better welding between layers with different material compositions, thereby maintaining weld seam strength while using diverse recycled materials for sustainability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite nonwoven laminate structure combining multiple recycled materials (rPET, rPP, TLO) in different layers. The intermediate layer of rPP nonwoven fabric serves as a bonding interface that enables effective composite material construction, allowing the integration of various recycled materials while maintaining structural integrity and weld seam strength.

Inventive Principle:
Principle #40Composite materials

2Strength

If material strips are used to reinforce the connecting seam to improve weld seam strength, then the strength increases, but the positioning difficulty and device complexity increase

Engineering Contradiction:
Improveweld seam strengthVSAvoidpositioning complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent extracts the reinforcement function from separate material strips and integrates it into the intermediate layer of the nonwoven laminate. This eliminates the need for separate positioning and attachment of material strips, simplifying the manufacturing process while maintaining weld seam strength enhancement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the reinforcement function with the intermediate layer structure. The intermediate layer itself provides the necessary strength enhancement through its material properties and positioning, combining multiple functions (intermediary action, reinforcement, and structural integration) into a single integrated component.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration significantly improves the maximum tensile force of the weld seams, ensuring stronger connections while maintaining the environmental benefits of using recycled materials, and simplifies the manufacturing process by eliminating the need for complex positioning of material strips.

Implementation Method 1

Longitudinal vibrations with frequencies of 20 kHz to 35 kHz and tool amplitudes of 5 μm to 50 μm are introduced under pressure into the nonwovens to be joined

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 2

The frictional heat caused by the vibrations melts the material of the nonwoven

Methodology Applied
Scientific EffectFrictional heating: Viscous Heating

Implementation Method 3

The melt of the intermediate layer, which includes rPP, acts as a welding agent between the layers

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3669734B1Vacuum cleaner filter bag with improved weld seam strength
Publication Date: 2021.02.03 EUROLIFTERS HLDG NV
  • EP3669734B1 patent drawingFigure 1~2

AI summary

The invention comprises a vacuum cleaner filter bag with a bag wall (1) comprising a support layer (8) comprising recycled polyethylene terephthalate, rPET, a fine filter layer (6) made of a meltblown nonwoven fabric comprising polypropylene, PP, PET and/or recycled polypropylene, rPP, and a capacity layer (5) made of a nonwoven fabric comprising rPET, recycled textile material, TLO, and/or rPP, wherein the bag wall (1) further comprises at least one intermediate layer (7) formed of a nonwoven fabric or a fibrous nonwoven fabric, and comprising rPP as the main component; and wherein the at least one intermediate layer is arranged between the support layer (8) and the fine filter layer (6) and/or between the fine filter layer (6) and the capacity layer (5).