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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
3 © Nonwovens Innovation & Research Institute Ltd
Our ServicesChemical & physical engineering of advanced materials & textiles
1
5 © Nonwovens Innovation & Research Institute Ltd
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
5 © Nonwovens Innovation & Research Institute Ltd
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
5 © Nonwovens Innovation & Research Institute Ltd
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
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
4 © Nonwovens Innovation & Research Institute Ltd
Our Expertise
Our core expertise is exploiting the
relationship between fibre science,
processing & structure to
achieve target performance.
Fibre
selection
Processing
3D
Architecture
5 © Nonwovens Innovation & Research Institute Ltd
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
6 © Nonwovens Innovation & Research Institute Ltd
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
9 © Nonwovens Innovation & Research Institute Ltd
ES Webs & Fibre
Morphology
PA,6
10 © Nonwovens Innovation & Research Institute Ltd
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
11 © Nonwovens Innovation & Research Institute Ltd
Solution Blowing
12 © Nonwovens Innovation & Research Institute Ltd
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).
14 © Nonwovens Innovation & Research Institute Ltd
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
16 © Nonwovens Innovation & Research Institute Ltd
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.
17 © Nonwovens Innovation & Research Institute Ltd
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
18 © Nonwovens Innovation & Research Institute Ltd
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
19 © Nonwovens Innovation & Research Institute Ltd
Particle Retention
19
Particles fully trapped beneath
top surface without adhesives
Particles retained within the pore structure, modulated further by
heat/pressure (if required).
20 © Nonwovens Innovation & Research Institute Ltd
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
22 © Nonwovens Innovation & Research Institute Ltd
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
24 © Nonwovens Innovation & Research Institute Ltd
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
25 © Nonwovens Innovation & Research Institute Ltd
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
26 © Nonwovens Innovation & Research Institute Ltd
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
28 © Nonwovens Innovation & Research Institute Ltd
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.
29 © Nonwovens Innovation & Research Institute Ltd
Thank you for your attention!