Nonwoven storage filters

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Solution Overview

Problem

Existing filter fleeces for general room and process air technology face challenges in maintaining low air resistance and initial pressure drop when treated with flame retardants, making them unsuitable for air conditioning systems due to increased noise and blower output requirements.

Innovation Solution

A specific nonwoven filter fleece is developed, combining antistatic, antimicrobial, and flame-retardant agents through a wet-chemical treatment, specifically using a layered structure of spunbonded, melt-blown, and dry-laid fleeces with selected additives like ammonium compounds and oligo/polyethylene glycol, which maintains low air resistance and initial pressure drop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If flame retardant treatment is applied to filter fleece, then fire protection is improved, but initial pressure drop increases significantly

Engineering Contradiction:

Improvefire protectionVSAvoidinitial pressure drop

Core Design Contradiction:

Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The patent changes the chemical composition parameters of the finishing agents, specifically using ammonium compounds and oligo/polyethylene glycol with controlled molecular weights and ratios. This chemical parameter optimization allows achieving flame retardancy while maintaining low pressure drop by reducing the finishing agent load on the filter fleece.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite finishing system combining multiple agents (ammonium compounds, oligo/polyethylene glycol, and optionally antimicrobial agents) in specific ratios. This composite approach allows the flame retardant properties to be achieved through synergistic interactions while the oligo/polyethylene glycol component specifically addresses the pressure drop issue by controlling the physical state and distribution of the finish on the fleece.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If flame retardant and antistatic treatment is applied to filter fleece, then fire protection and static control are improved, but air permeability decreases

Engineering Contradiction:

Improvefire protection and static controlVSAvoidair permeability

Core Design Contradiction:

Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent optimizes the molecular weight parameters of the oligo/polyethylene glycol component and the concentration ratios of finishing agents. By controlling these parameters, the finish forms a more open structure that maintains air permeability while providing the required flame retardant and antistatic properties.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses oligo/polyethylene glycol as a carrier that copies or facilitates the uniform distribution of the ammonium compound finishing agent across the filter fleece surface. This ensures consistent performance with minimal material loading, preserving air permeability.

Inventive Principle:

Principle #26Copying

3Object-affected harmful factors

If heavy finishing treatment is applied to achieve flame retardancy, then fire protection is improved, but noise development increases

Engineering Contradiction:

Improvefire protectionVSAvoidnoise development

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent reduces the total loading of finishing agents on the filter fleece by optimizing the chemical composition and ratios. Specifically, the use of ammonium compounds with controlled concentrations and the inclusion of oligo/polyethylene glycol allows achieving flame retardancy with lower overall finish content, thereby reducing the mass and structural changes that cause noise during air flow.

Inventive Principle:

Principle #35Parameter changes

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 filter fleece achieves excellent performance for pocket filters in air conditioning systems with an initial pressure drop of up to 200 Pa, maintaining dust storage capacity and air permeability while providing fire protection and antimicrobial properties.

Implementation Method 1

a) a nonwoven filter fleece for pocket filters for general room and process air technology

Methodology Applied

Scientific EffectPhysical barrier filtration: Filter (physical)

Implementation Method 2

combining antistatic, antimicrobial, and flame-retardant agents through a wet-chemical treatment, specifically using a layered structure of spunbonded, melt-blown, and dry-laid fleeces with selected additives like ammonium compounds and oligo/polyethylene glycol

Methodology Applied

Scientific EffectFlame retardant chemical treatment:

Implementation Method 3

combining antistatic, antimicrobial, and flame-retardant agents through a wet-chemical treatment

Methodology Applied

Scientific EffectAntistatic agent treatment:

Implementation Method 4

combining antistatic, antimicrobial, and flame-retardant agents through a wet-chemical treatment

Methodology Applied

Scientific EffectAntimicrobial agent treatment:

Implementation Method 5

maintaining low air resistance and initial pressure drop... maintaining dust storage capacity and air permeability

Methodology Applied

Scientific EffectAir permeability through porous structure: Porosity

Data Source

PatentEP2552566B1Nonwoven storage filters

Publication Date: 2017.09.20 DENCOHAPPEL GMBH

AI summary

The invention relates to a nonwoven filter, e.g. for bag filters for general room and process ventilation and air conditioning technology as well as to a method for the production thereof.