Multi-Strand Filament for Applicator Bristles

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Solution Overview

Problem

Existing materials for 3D-printing filaments are unsuitable for providing the required properties for bristles of cosmetic or dental applicators, particularly lacking stiffness, retention, and liquid absorption capabilities.

Innovation Solution

A multi-strand filament design comprising at least two strands, where a first strand provides stability and bend-recovery capacity, and a second strand with capillary action for liquid transport, connected through co-extrusion to ensure structural integrity and efficient liquid handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single-material filament is used, then the manufacturing process is simple, but the bristle lacks both stiffness and liquid absorption capability

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidfunctional performance

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies composite materials by combining a first material (providing stiffness and bend recovery) with a second material (providing capillary action for liquid transport) into a single multi-strand filament structure. This allows the bristle to simultaneously achieve mechanical stability and liquid absorption capabilities that neither material could provide alone.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The filament is segmented into multiple strands with different materials - at least one first strand and at least one second strand - each performing specific functions. The first strand provides structural support while the second strand handles liquid transport, allowing independent optimization of each material's properties.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If a multi-material filament is used, then the bristle achieves both stiffness and liquid absorption, but the manufacturing complexity increases

Engineering Contradiction:

Improvefunctional performanceVSAvoidfilament structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple material functions into a single integrated filament structure where first strands and second strands are combined in one element. This consolidation achieves the benefits of multi-material performance while maintaining relative manufacturing simplicity through co-extrusion or twisting processes.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If strands are loosely connected, then the filament is easy to manufacture, but the strands separate during processing and use

Engineering Contradiction:

Improveassembly simplicityVSAvoidstrand retention

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The first strand is configured to partially surround the second strand in a curved, encompassing manner rather than a loose linear arrangement. This geometric configuration provides mechanical interlocking that prevents separation during processing and use while maintaining manufacturing feasibility.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The filament structure nests the second strand within the怀抱 of the first strand, creating a hierarchical arrangement where the surrounding strand provides structural support and containment. This nested configuration ensures strands remain connected during processing and application.

Inventive Principle:

Principle #7Nested doll (Nesting)

4Reliability

If the first strand fully surrounds the second strand, then strand retention is improved, but liquid absorption capability decreases

Engineering Contradiction:

Improvestrand retentionVSAvoidliquid absorption

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The first strand partially surrounds the second strand rather than fully enclosing it, creating different functional zones: the surrounded region provides structural stability while the exposed regions of the second strand maintain accessibility for liquid absorption through capillary action. This localized quality differentiation optimizes both retention and absorption.

Inventive Principle:

Principle #3Local quality

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 multi-strand filament achieves suitable properties for applicator bristles with combined stiffness, retention, and liquid absorption, ensuring precise application and effective liquid transport.

Implementation Method 1

the at least one second strand consists of a second material which exhibits a capillary action by means of which it can store, transport and/or release a liquid

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

the first strand provides stability and bend-recovery capacity

Methodology Applied

Scientific EffectElastic recovery: Elastic Recovery

Data Source

PatentEP4575052A1Multi-strand filament

Publication Date: 2025.06.25 GEKA

Figure 1

AI summary

Multi-strand filament for the manufacture of bristles for an applicator, comprising at least two strands which are firmly connected to one another, wherein a first strand only partially surrounds at least one second strand in the circumferential direction thereof.