Application of Nanotechnology in Nonwovens

Application of Nanotechnology in

Nonwovens

Dr. Vera Chetty, Chief Technical Manager

Dr. Matthew Tipper, Business Director

Nonwovens Innovation and Research Institute, Leeds, UK

March 2019

2 © Nonwovens Innovation & Research Institute Ltd

Introducing NIRI

Global Leader in Nonwoven & Textile

Engineering

Originally spun-out from University of Leeds in 2005 to focus

on:

• Applied research

• Industrial innovation

• Product development & Commercialisation

Our Industrial Expertise & Academic Excellence

maximises the value of your R&D investments


Our ServicesChemical & physical engineering of advanced materials & textiles

1


Understand

Concept development, reverse engineering, benchmarking, compositional analysis, market identification

Develop

Proof of concept, technical feasibility, prototyping, new material evaluation

Deliver

Scale up, validation, cost reduction, process optimisation

Our Services


Understand


Develop


Deliver


Our Services


Understand


Develop


Deliver


Our Services

1. Understand• Concept development• Reverse engineering• Benchmarking• Compositional analysis• Market identification

2. Develop• Proof of concept• Technical feasibility• Prototyping• Raw material validation• In-depth analysis

3. Deliver• Scale-up• Validation & Specification• Cost reduction• Process optimisation• Supporting data for

marketing claims


Our Expertise

Our core expertise is exploiting the

relationship between fibre science,

processing & structure to

achieve target performance.

Fibre

selection

Processing

3D

Architecture


Why NIRI?

Confidentiality

is paramountYou own 100%

of the IP in your

field

Successfully

completed >400

projects

Extensive pilot

plant, testing

and analysis

facilities

Academic rigour

Industrial excellence


What is a Nonwoven

Fabric?

“A fabric made directly from a web of fibre (or filaments), without the yarn

preparation necessary for weaving and knitting”.

Woven: interlaced Knitted: intermeshedNonwoven

How can we introduce nanotechnology

to nonwovens?

1. Create and deposit nanofibres directly as a web (nanomaterial itself).

2. Use a nonwoven as a carrier substrate for nanomaterials in non-fibre

form.

Electrospinning

http://youtu.be/T8e5_6ulIzQ


ES Webs & Fibre

Morphology

PA,6


Forcespinning High speed rotating vessel

Centrifugal force pushes polymer

through the orifice; stretching due to

rotational inertia

Can process solution and melt polymer

Fibres diameters 200-1000 nm

http://youtu.be/wKy70zqbk_w


Solution Blowing


Nanofibre Nonwoven

Applications

Protection: Sound absorption materials,

protective clothing against chemical and

biological warfare agents, sensor applications

for detecting chemical agents.

Medical: Artificial organ components, tissue

engineering and implants, drug delivery, wound

dressings.

Energy: Batteries, photovoltaic cells, polymer

electrolytes, membrane fuel cells.

Filtration: HVAC, HEPA, ULPA high efficiency

filters; air, oil, fuel filters for automotive, filters for

beverages, pharmaceuticals and blood.

Wearables: Sport apparel, sport shoes, rainwear

and outerwear garments, baby diapers.

How can we introduce nanotechnology

to nonwovens?

1. Incorporate particles within a nonwoven structure (in the pores).

2. Incorporate particles within a polymer matrix (in the fibres).

3. Apply particles within a finish treatment (on the fibre surface).


Nanoparticle Type

Carbon black

Carbon nanotubes (CNT)

Nanoclay

Metal oxides (TiO2, ZnO, Fe7O3, SiO2, Al2O3,etc.)

Silver, zinc, etc.

Silica, aerogel

15

Liquid absorbency & retention Adsorption (odour, VOCs) Antimicrobial/biocidal Acoustic/Thermal Management Flame retardance Oleophilicity Magnetism UV/IR/EMS Absorption Increased bulk and thickness

Nanoparticle Functionality


Nanoparticle Injection

Technology

o Joint venture development.

o Direct mechanical injection of dry

particles (e.g. powders) or wet slurries

inside preformed nonwovens, retained

without adhesives.

o Multiple material compatibility.

o Continuous line speed up to 600 m.min-1.


Powder Distribution

Nonwoven pore structure controls depth

of particle penetration and retention

<250μm

>250μ <600μm

>600μm

Particles are unable to pass through the entire structure due to

frictional resistance and pore structure within the lowest layer


Particle Injection

Particles deposited

on top surface of

the nonwoven

Energy transmitted directly

to the particles to drive

transit between fibres, and

enable 3D penetration

Continuous feed


Particle Retention

19

Particles fully trapped beneath

top surface without adhesives

Particles retained within the pore structure, modulated further by

heat/pressure (if required).


Nanoparticle Compounding

Compounding is a process

of blending additives

(nanoparticles) with a

polymer at a higher

concentration than required

in the final product.

Compounded polymer

masterbatch is extruded

into filament strands,

cooled and pelletised.

PET, PP, PE, PA, etc.

Metal oxidesCNTNanoclaySilver, zincSilica, aerogel

Extrusion

The compounded masterbatch is mixed

with the base polymer before or inside

the extruder.

PolymerMasterbatch Meltblown

nonwoven

PolymerMasterbatch

Spunbondnonwoven

Filaments

The polymer melt with homogeneously dispersed nanoparticles is

extruded into filaments by means of filament extrusion, spunbond,

meltblown or melt forcespinning process.

PolymerMasterbatch

Filaments

Crimped, cut intofibres

< 11mm

3mm<<11mm

1mm<<5mm

< 1mm


Solution Spinning

Finish Treatment

Polymer solution with dispersed nanoparticles is spun into particle loaded

nanofibre web by means of electrospinning or solution forcespinning.

Dispersion of nanoparticles in a finish or binder formulations and applied

onto a pre-formed nonwoven by means of:

Coating

Impregnation

Printing

Spraying

Finish

Finish impregnation

FinishAir

Finish

Air filtration: using Metal Organic

Frameworks (MOFs) to remove VOCs

from air


What are MOFs

MOFs are crystalline materials, a subclass of coordination

polymers

Microporous structure with enormous surface area

Consist of metal ions/clusters and organic ligands = high

variability of different structures and composition

OxygenCarbonZinc


VOC Removal from Air

Volatile organic compounds (VOCs) are compounds that easily become

vapours or gases.

Released from burning fuel and from many consumer products.

Deleterious to human health.

Ammonia, Acetaldehyde, Formaldehyde, NO2, O3, SO2, Benzene


Prototyping and Testing

Lightweight spunbond was loaded with

Activated Carbon and MOFs using

Particle Infusion.

Particle loading was approximately 50%

wt.

Subjected to analysis using Dynamic

Vapour Sorption (DVS) against

Ammonia.

100

104

108

112

116

120

124

Change in Mass

Target P/PO

Ch

an

ge

in

Ma

ss (

%)

Activated Carbon

0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800

100

104

108

112

116

120

124

Time (min)

Metal Organic Framework

0

10

20

30

40

50

60

70

80

90

100

Ta

rge

t P/P

O (%

)

Increased ammonia adsorption


Summary

Nano-nonwovens can be produced by either deposition of nanofibres or by

using the nonwoven as a carrier for nanomaterials.

Nanoparticle Injection Technology can offer a fast method of directly

incorporating nanomaterials into a carrier nonwoven substrate.

Nanoparticle incorporation into fibres and filament forming a nonwoven

fabrics.

It is feasible to impregnate nonwovens with nanoparticles such as MOFs.

MOFs show promise in reducing VOC’s from air streams and could improve

interior air quality.


Thank you for your attention!

Application of Nanotechnology in Nonwovens

Documents

Transcript of Application of Nanotechnology in Nonwovens