Antimicrobial Core-Sheath Filter Medium for Pool Water Biofilm Control

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Solution Overview

Problem

Conventional pool filters, particularly those using polyester fabric, face issues with clogging and difficulty in cleaning due to oil buildup and biofilm formation, leading to inefficient removal of microorganisms and potential health risks.

Innovation Solution

A bi-component fiber-based water filter medium with an antimicrobial agent in the sheath polymer, specifically core-sheath polyester fibers, is developed to effectively combat bacterial growth and contamination, featuring a melting point difference between core and sheath polymers for bonding and porosity, and incorporating antimicrobial additives like silver-ions for microbial inhibition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If polyester fabric filter is used for filtration, then contaminants can be removed, but the filter gets clogged quickly with oils, microorganisms and biofilm making it difficult to clean

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidcleaning difficulty
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by incorporating antimicrobial agents into the filter medium during manufacturing, before the filter is put into service. This pre-treatment prevents biofilm formation and microbial growth from the outset, eliminating the need for difficult cleaning operations later. The antimicrobial protection is built-in from the beginning, addressing the cleaning difficulty problem before it arises.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the chemical parameters of the filter medium by incorporating antimicrobial substances and modifying the polyester fabric properties. This parameter change transforms the filter from one that accumulates biofilm to one that actively resists microbial growth, thereby solving the cleaning difficulty while maintaining filtration efficiency.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If continuous filtration is performed to remove contaminants, then water quality improves, but microorganisms can still grow and form biofilm on the filter

Engineering Contradiction:
Improvewater qualityVSAvoidbiofilm formation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of microbial presence into a benefit by using antimicrobial agents that target and eliminate the harmful microorganisms. The filter medium is designed to interact with microorganisms in a beneficial way - capturing them for filtration while simultaneously neutralizing their ability to form biofilm through the antimicrobial treatment.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent applies preliminary anti-action by incorporating antimicrobial substances that preemptively counteract microbial growth and biofilm formation. Before microorganisms can establish themselves and create harmful biofilm on the filter, the antimicrobial agents already present in the filter medium prevent their proliferation, thus eliminating the harmful effect before it can develop.

Inventive Principle:
Principle #9Preliminary anti-action

3Productivity

If filter cleaning is performed frequently to maintain efficiency, then filtration performance is maintained, but the polyester fabric degrades and porosity decreases

Engineering Contradiction:
Improvefiltration performanceVSAvoidfilter lifespan
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary action by equipping the filter medium with antimicrobial protection before it is installed and used. This pre-treatment prevents biofilm accumulation that would otherwise require frequent cleaning, thereby reducing the frequency of cleaning operations and extending the filter's operational life without compromising filtration performance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent effectively creates a long-lasting filter medium that does not require frequent replacement or intensive cleaning. By incorporating antimicrobial agents, the filter maintains its performance characteristics over an extended period, reducing the need for premature replacement and maximizing the service life of the filtration system.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 antimicrobial filter medium provides enhanced efficiency in removing oils, dirt, debris, and microorganisms from pool water, reducing maintenance needs and ensuring better sanitation with improved durability and porosity, while maintaining the antimicrobial effectiveness.

Implementation Method 1

The filter medium is comprised of a majority of core-sheath fibers with the sheath portion containing an antimicrobial agent

Methodology Applied
Scientific EffectCore-sheath fiber structure:

Implementation Method 2

The core and sheath polymers have a melting point difference of at least 20°C, such that the sheath polymer can be melted without melting the core polymer

Methodology Applied
Scientific EffectMelting point difference bonding: Melting

Implementation Method 3

the sheath portion containing an antimicrobial agent in an amount of from 0.1 to 10.0 wt%, based on the weight of the total fiber

Methodology Applied
Scientific EffectAntimicrobial inhibition:

Implementation Method 4

The filter media can be configured in a filter cartridge or other configurations known in the art that are readily adapted to the final application

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP1856974B2Antimicrobial water filter medium
Publication Date: 2016.01.13 JOHNS MANVILLE CORP

AI summary

Provided is a filter medium comprised of core-sheath fibers wherein the sheath portion comprises an effective amount of antimicrobial agent. Preferably, all fibers of the filter medium comprise such core-sheath fibers, so that every fiber of the filter medium contains the antimicrobial agent to effectively deter bacterial growth.