Antibacterial Bicomponent Nonwoven Wipe for Wash-Resistant Silver Retention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing antimicrobial nonwovens with silver treatment are not long-term effective due to silver being superficially applied and washed away, leading to economic losses and environmental concerns.

Innovation Solution

Incorporating antimicrobial dopants into bicomponent fibers within nonwoven fabrics, which are then solidified using processes like water jet finishing or thermal treatment, ensuring the dopant remains bound and is released in small quantities, maintaining antimicrobial effectiveness while allowing for multiple washes without significant silver loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silver is applied superficially to nonwoven fabric, then antimicrobial effect is achieved initially, but silver is washed away during washing processes

Engineering Contradiction:
Improveantimicrobial effectivenessVSAvoidsilver loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The silver dopant is nested within the fiber body structure of the bicomponent fibers. The antimicrobial substance is incorporated into the fiber matrix during manufacturing, creating a nested configuration where the active ingredient is protected within the fiber structure rather than applied on the surface. This nesting approach prevents silver loss during washing while maintaining antimicrobial effectiveness.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Bicomponent fibers with different material properties are used to create a composite fiber structure. One component provides structural integrity while the other component incorporates the silver dopant. This composite approach allows the silver to be integrated into the fiber body in a way that prevents washing away, resolving the contradiction between maintaining antimicrobial effect and preventing silver loss.

Inventive Principle:
Principle #40Composite materials

2Loss of substance

If bicomponent fibers with dopant are used and solidified, then wash resistance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvedopant retentionVSAvoidfiber structure complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The phase behavior of the bicomponent fibers is exploited to achieve solidification. By controlling the thermal or chemical parameters during finishing, one component of the bicomponent fiber undergoes phase change to form a rigid matrix that binds the dopant. This parameter-based approach achieves dopant retention without requiring complex structural modifications to the fiber itself.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The bicomponent fiber structure acts as an intermediary between the dopant and the external environment. The fiber composition is designed so that one component serves as a binding matrix that mediates between the dopant and washing conditions, protecting the dopant from being washed away while maintaining simple fiber geometry.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Duration of action of stationary object

If endless fibers are used in nonwoven fabric, then wash resistance is improved, but fiber production complexity increases

Engineering Contradiction:
Improvewipe durabilityVSAvoidfiber production
Core Design Contradiction:
Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

The continuous fiber structure serves multiple functions simultaneously: it provides mechanical strength, creates an intertwined network for durability, and offers a continuous matrix for dopant incorporation. By using continuous fibers instead of staple fibers, the same material achieves both durability through intertwining and simplified dopant integration, resolving the contradiction between durability and manufacturing ease.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 nonwoven fabric exhibits high wash resistance and reactivity, preventing bacterial decomposition and odor pollution, with energy savings of over 3 kWh/kg per wash, and is safe for human skin contact.

Implementation Method 1

The splitting can be carried out, for example, using a water jet needling process, whereby the elementary fibers are additionally intertwined with one another.

Methodology Applied
Scientific EffectWater jet needling: Jet Erosion

Implementation Method 2

It is also conceivable to solidify the nonwoven material through a thermal treatment.

Methodology Applied
Scientific EffectThermal treatment: Heat Treatment

Data Source

PatentEP2103724B1Wiping cloth with an antibacterial non-woven fabric
Publication Date: 2011.06.08 CARL FREUDENBERG KG
  • EP2103724B1 patent drawingFigure 1
  • EP2103724B1 patent drawingFigure 2

AI summary

The non-woven fabric comprises continuous bi-component fibers. The body of the fiber includes at least one anti-microbial dopant. A novel feature is use of bi-component fibers split into elementary fibers. The surface density is 1200-3250 m 2>/kg. The elementary fibers have a fineness of 0.05-1 dtex. The dopant is uniformly distributed in only in one component of the body of the fiber. Its concentration is at least 100 ppm and preferably no more, although up to 500 ppm may be present. One component of the fiber body is polyamide or polyethylene. The other is polyethylene terephthalate or polyester. The dopant is uniformly-distributed in the polyethylene terephthalate or polyester component. The bi-component fiber is in the form of a PIE fiber. The dopant is an element of a sub-group, especially the 1b sub-group. It is silver, gold or copper. The superficial weight is at least 20 g/m 2>. The fleece is dyed. The water absorption capacity is at least 350 wt% based on the dry weight of the nonwoven fabric. After a domestic wash at boiling point in accordance with DIN EN ISO 6330, the absorption is at least 400 wt% based on the dry weight.