Core-Sheath Air Filter for Radiation Resistance and Sealing

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Solution Overview

Problem

Conventional air filters with high melting temperature porous separation layers face issues with mechanical stability and leaks due to incomplete sealing during the embedding process, especially in single-layer membrane filter elements, which are prone to excessive forces and cannot be sterilized effectively.

Innovation Solution

The use of a porous air filter with a separating layer made of polyolefin core sheath fibers, where the sheath material has a lower melting temperature than the core material, ensuring complete melting and shrinkage during anchoring, thereby achieving a firm embedding and avoiding bypasses, and allowing for radiation resistance and gentle pleating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional high melting temperature porous separation layers (PET spunbonds) are used, then radiation resistance is achieved, but mechanical stability and sealing quality deteriorate due to incomplete melting during anchoring

Engineering Contradiction:
Improveradiation resistanceVSAvoidsealing quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent uses composite fibers with a core-sheath structure where the core provides radiation resistance (high melting point material) and the sheath provides good sealing properties (lower melting point material). This composite structure allows both requirements to be met simultaneously - the core maintains structural integrity under radiation while the sheath melts properly during anchoring to create secure seals.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different parts of the fiber have different properties: the core material has high melting temperature for radiation resistance while the sheath material has lower melting temperature for good sealing. This local differentiation of material properties within the same fiber enables simultaneous achievement of both radiation resistance and sealing quality.

Inventive Principle:
Principle #3Local quality

2Strength

If fiber thickness and separating layer thickness are increased to improve mechanical stability, then strength improves, but sealing quality worsens due to insufficient melting

Engineering Contradiction:
Improvemechanical stabilityVSAvoidsealing quality
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The core-sheath composite fiber structure allows thicker fibers to be used for improved mechanical stability while the sheath material's lower melting point ensures complete melting and good sealing. The composite structure decouples the relationship between fiber thickness and sealing quality.

Inventive Principle:
Principle #40Composite materials

3Device complexity

If single-layer membrane filter elements are used, then device complexity is reduced, but mechanical stability and resistance to embedding forces deteriorate

Engineering Contradiction:
Improvefilter element structureVSAvoidmechanical stability
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The core-sheath composite fibers in the single-layer membrane provide enhanced mechanical stability through the combination of high-strength core material and supportive sheath material, allowing single-layer construction to achieve the mechanical stability previously requiring multi-layer structures.

Inventive Principle:
Principle #40Composite materials

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 provides a radiation-resistant air filter with enhanced mechanical stability and complete sealing, preventing leaks and allowing for sterile filtration without the need for autoclaving, while maintaining the integrity of hydrophobically modified membrane layers.

Implementation Method 1

the sheath material having a lower melting temperature than the core material; wherein the porous sheet has a radiation resistance of at least 20 kGy

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

the porous sheet has a radiation resistance of at least 20 kGy

Methodology Applied
Scientific EffectRadiation resistance: Radiation

Data Source

PatentEP3509728B1Air filter, method for its manufacture and its use
Publication Date: 2022.11.30 SARTORIUS STEDIM BIOTECH GMBH
  • EP3509728B1 patent drawingFigure 1A~1B
  • EP3509728B1 patent drawingFigure 2A~2B
  • EP3509728B1 patent drawingFigure 3A~3C

AI summary

The invention relates to a porous textile fabric, a filter element comprising the porous textile fabric, to a method for producing the porous textile fabric, to a method for producing the filter element and to the use of the textile fabric and the filter element.