Embed Size (px)
Citation preview
Comfort and Hygiene of Textiles
Centexbel - Mark Croes
Introduction
Centexbel
Technical and Scientific Textile Centre
independent and objective advice
the expertise of 150 highly educated
collaborators
transsectorial and international networking
focus on sustainable development
practice-oriented support
partnership
an open approach
3
Products & Activities
4
Centexbel - testing
fire
FR - properties
flame propagation
fumes
smoke density …
fysical
abrasion
color fastness
anti-static
Waterproof …
chemical
permeation
heavy metals
emission
fibre identification …
microbiological
barrier properties
cleanroom
anti-microbial
cytotoxicity …
Accredited Laboratories
5
certification
PPE
Toys
Carpet
Coaches
floor- and wall coverings
textiles and
harmful substances
sustainable production processes
recycling
Centexbel – certification and services
services
consultancy
training
standardisation and legislation
patent support
publications – website –
brochures – social media - …
6
Comfort and Hygiene of Textiles
Negative story
Harmful Substances
Environmental Concerns
Eco-toxicity
REACH
PROBLEM SOLVING Product Modification process Modification
Eco-certificates 7
Comfort and Hygiene of Textiles
Positive story
New Applications
High Performance Products
Added Value
INNOVATION (Multi) Functionalisation New textile fibres/yarns/fabrics New additives/coatings/polymers
8
Developments
COMFORT
HYGIENE
9
Comfort
Dexterity
Size and color stability
Stiffness/softness
Thermal Comfort
Skin Tolerance
10
Hygiene
Bio-active textile Fibre properties (bamboo)
Biocides
3D-structuren (ventilation)
Release
finish
coating
microcapsules
fibre incorporation
11
Thermo-physiological comfort
of textile
Two types of comfort:
Sensorial comfort Comfort or discomfort related to sensation
induced by contact between skin and textile
Thermophysiological comfort Comfort or discomfort related to transfer of heat
and moisture through textile
Comfort or discomfort related to sensation of hot or cold
13
Thermoregulatory properties
Thermal insulation
Water vapour transmission (breathability)
Liquid sweat management (wicking)
Air permeability
Water penetration resistance and repellence
14
Rct and Ret
2 important parameters of textile thermal comfort
Thermal insulation
Thermal resistance [Rct] (insulation)
Water vapour transmission (breathability)
Water vapour resistance [Ret] (breathability-1)
Measuring devices
Skin-model or Sweating Guarded Hot Plate
(measurement on fabrics)
Thermal and sweating manikin (measurement on
garments)
15
Skin Model (ISO 11092)
16
Skin Model (SDL Atlas)
17
Skin model - Thermal resistance [Rct]
Sample
0
)(ct
c
amct R
HH
ATTR
Hot plate
(dry)
Ta = 20°C
hr,a = 65 %
Thermal guard
Tm = 35°C
T = 35°C
[ m2·K/W ]
18
Skin model - Water-vapour resistance [Ret]
Cellophane
Thermal guard
Sample
T = 35°C
Tm = 35°C
Ta = 35°C
hr,a = 40 %
0
)(et
e
amet R
HH
AppR
Hot plate
with water
[ m2·Pa/W ]
19
Rct : Thermal Resistance
Units:
Standard Unit: [m².K/W]
1 tog = 0,1 m².K/W
1 CLO = 0,155 m².K/W
Typical values: Clothing example m2.K/W
Shirt 0.01
Underwear 0.02 – 0.04
Thermal underwear 0.04 – 0.08
Sweaters 0.10
Firemen jacket 0.10
Blankets 0.10 – 0.20
Continental quilts 0.50 – 1.50
20
Ret : Evaporative Resistance
Unit:
Standard unit: [m².Pa/W]
Typical values:
EN 343: rain protection:
Taiwan Textile Institute:
Satisfactory
1
Good
2
Very good
3
Ret ≥ 40 20 ≤ Ret < 40 Ret < 20
Ret values [m2.Pa/W]
Excellent < 6
Very good 6 ≤ Ret < 13
Good 13 ≤ Ret < 27
Moderate 27 ≤ Ret < 40
Fair 40 ≤ Ret < 50
21
Thermal and sweating manikin
22
Thermal and sweating manikin
23
Climatic chamber
T° : 10 °C … 35 °C,
HR : 30% … 80%
Vair : 0.2 m/s … 0.6 m/s
24
Thermal resistance (insulation)
25
Thermal resistance (insulation)
26
Thermal resistance (insulation)
27
Water vapour resistance
28
Protective clothing: standards using thermal manikin
EN 342 Cold
EN 14058 Cold
29
Wicking (liquid sweat management)
Definition
Wicking is the capability to transport liquid water (sweat)
in textile fabrics
Scope
Textile fabrics in contact with the skin
30
Wicking vs. comfort
Good wicking allows the skin remaining dry
Avoid excessive cooling due to evaporation (thermal
comfort)
Avoid friction (sensorial comfort)
31
Wicking vs. comfort
Skin
Fabric
sweat
Skin
Fabric
sweat
Comfort Good Bad
32
Moisture Management Tester (AATCC 195)
33
Measuring unit (bottom)
34
Sample placement
Sample size = 8 cm x 8 cm 5 specimens are tested
35
MMT: principle
0.21 g ~ 20s
36
MMT: results
10 parameters
Wetting time [s] (B, T) 2
Absorption rate [%/s] (B, T) 2
Max wetted radius [mm] (B, T) 2
Spreading speed [mm/s] (B, T) 2
One way transport capability (R) 1
Overall moisture management capacity (OMMC) 1
37
Overall moisture management capability
(OMMC)
OMMC depends on
Absorption rate (bottom) ARB
Spread speed (bottom) SSB
One-way transport capacity R
OMMC = 0.25*ARB_ndv + 0.5*Rndv + 0.25*SSB_ndv
0 < OMMC < 1
OMMC = 0 : comfort = bad
OMMC = 1 : comfort = good
38
Thermo-physiological Comfort
Research and problem solving in with Thermal
Manikin and Infrared Camera
skin-model vs. manikin
Skin-model
Measure on fabrics
De facto standard for measuring comfort
Widely used for protective clothing
Lower cost
Manikin
Measure on garments
Closer to reality
Take microclimate effect into account
Input for predictive models
Research and development tool
40
Thermal manikin: examples of
applications Tests at various conditions
Tests of new products
Measure of wicking
Other products:
Mattress ticking, mattress cover,…
Sleeping bag
…
41
Thermal manikin: test of new
products An example
Luxicool®
Coolmax®
42
Thermal manikin: test of new
products
Heat flux W/m²
0
50
100
150
200
250
300
350
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
L Forearm Q/A 6 W/m^2
Placement of
the sleeve
Luxicool® Placement of
the sleeve
Coolmax®
43
Thermal manikin: mattress,
mattress cover, mattress ticking
44
Thermography
45
Thermography: biker jacket
46
Thermography: hot socks
47
Antimicrobial Finishes
Antimicrobial treatments
= Treatments performed on textiles in order to :
• limit or reduce the growth of some microorganisms
“Bacteriostatic” or “fungistatic” treatments
• kill the micro-organisms
Bactericide or fungicide treatments
2 possibilities :
1) Protect the textile from the biodegradion
2) Give to the textile an additional functionality
49
Practical applications
Out-Door : Tents, Uniforms, Jackets, Sunshades, …
Domestic : Curtains, Coverings, Cloths, Bath mats, …
Technology : Wall hangings, Roof coverings , Air filters,
Automotive furnishings, Geotextiles
50
Micro-organisms
Virus
Bacteria (G+, G-)
Fungi
Alga
In the laboratory , only
those micro-organisms
51
Bacteria
Bacteria
Prokaryote
Wall
Ribosome's
Inclusions
Membrane cytoplasmique
DNA
Gram +
Gram -
52
FUNGI
Eukaryotes
Fungi filamentous
Yeast
Fungi
Fungi filamentous Yeast
53
Testing methods
Need that the active substance can
diffuse out of the textile
Qualitative or semi-quantitative methods
Agar diffusion test
Quantitative methods
Suspension or challenge test
Important distinction between two different types
of test systems
ASSESSMENT OF ANTIBACTERIAL TREATMENTS
54
ANTIBACTERIAL EFFICIENCY
Agar diffusion plate test
TEST PRINCIPLE :
• Test performed in a Petri Dish under sterile conditions
• Test specimen is pressed on an agar medium whose upper
layer has been inoculated with a bacterial strain
Strains generally used :
- Staphylococcus aureus ATCC 6538 (Gram+ bacterium)
- Escherichia coli ATCC 11229 (Gram- bacterium)
- Klebsiella pneumoniae ATCC ATCC 4352 (Gram- bacterium)
55
Agar diffusion
test
Sample
Agar with bacteria
Inhibition zone (ZI)
Incubation of the plate :
Temperature 37
Duration 18-24 hours
56
ANTIBACTERIAL EFFICIENCY
Agar diffusion test - illustration
Visual observation
Interpretation :
No growth below test specimen
(even without inhibition zone)
= Efficacy
EN 20645
57
ANTIBACTERIAL EFFICIENCY
Challenge tests
TEST PRINCIPLE :
• A known amount of bacteria are put in contact with the
antibacterial treated textile during a certain time
• After the incubation the bacteria remaining still alive
are counted
Strains generally used :
- Staphylococcus aureus ATCC 6538 (Gram+ bacterium)
- Escherichia coli ATCC 11229 (Gram- bacterium)
- Klebsiella pneumoniae ATCC 4352 (Gram- bacterium)
58
Textile + Bacteria (direct contact with bacteria)
Textile + Bacteria (liquid medium)
Strong agitation
SHAKE FLASK
ANTIBACTERIAL EFFICIENCY Challenge tests
!! 2 different concepts
59
Shake Flask test
ASTM E2149
Contact : textile – bacteria
in a liquid
Small pieces of the textile sample Strong agitation
Contact time : 1 hour
Results after 1 hour contact time
1
10
100
1000
10000
100000
Staphylococcus aureus Klebsiella pneumoniae
Ba
cter
ia c
on
cen
tra
tio
n i
n t
he
liq
uid
(CF
U/m
l)
Strain alone Untreated sample
Antibacterial treated sample
Bacteria in a known
concentration in the liquid
60
ANTIBACTERIAL EFFICIENCY
Shake Flask test
• Only suitable to assess the antimicrobial activity
of immobilized agents under dynamic conditions
• Method non valid for diffusive antibacterial products
Standard : ASTM E2149
61
Challenge test – Absorption
method
Absorption Inoculation with
bacteria
Pieces of textile
Contact time
1h, 6h, 18h, 24h
Extraction
Counting
Calculation
Incubation at 37°C
62
Challenge test – Transfer method
Contact time
18h - 24h
Extraction
Counting
Calculation
Incubation at 37°C
Step 1. Test bacteria are inoculated on the surface of an agar plate
Step 2. Sample is placed on the agar surface covered by bacteria
Step 3 : Sample is removed (bacteria are transferred onto the sample)
Bacteria transferred
63
ANTIBACTERIAL EFFICIENCY
Challenge tests - Conclusion Advantages for that kind of test :
٧ Quantitative results are obtained
Possible to obtain a kinetic of the action of the antibacterial
product (by using different contact times for example)
Give a more precise idea of the real effect of the antibacterial
treatment (in terms of level of bacteria reduction obtained)
Bacteriostatic versus Bactericide
٧ In general , suitable for diffusive and non difusive
antimicrobial finishes except the shake flask test
64
Testing methods
Need that the active substance can
diffuse out of the textile
Qualitative or semi-quantitative methods
Agar diffusion test
Quantitative methods
ASSESSMENT OF ANTIFUNGAL TREATMENTS
For all kinds of antifungal
Do not exist !
Soil burial test
Saturated atmosphere
65
Agar medium
Inoculation fungi :
• agar medium Sample
• sample
Incubation : 2 to 14 or 28 days
28°C
Inhibition zone (ZI)
Test principle
Visual or under the microscope
(growth on, beneath and around the sample (ZI)
ANTIFUNGAL EFFICIENCY
Agar diffusion plate test
Interpretation :
66
ANTIFUNGAL EFFICIENCY
Conclusion
Agar diffusion test : (same as for the antibacterial efficiency)
٧ Easy to perform by qualified personnel
٧ Only visual observation (naked eye and binocular)
٧ Low cost when using only 1 strain but sometimes very expensive due to the use of a blend of fungi
But : only possible for antifungal products that can diffuse out of the textiles
Problem with new antifungal textiles !!
No quantitative method available
67
Interpretation :
• visuel + control
Incubation : 7 to 14 days
28°C
Eau
Fungi
TEST IN SATURATED ATMOSPHERE
ANTIFUNGAL EFFICIENCY
Saturated atmosphere
68
ANTIFUNGAL EFFICIENCY
Conclusion
Saturated atmosphere :
٧ Test performed on textiles which are used in humid atmosphere assess generally the treatments done in order to protect the textile against the biodegradation
٧ Difficult to perform – inoculation sometimes by spray, aerosols qualified personnel ; biosecurity rules
٧ Difficulty = work in a “reproducible” way
٧ Expensive Always performed with a blend of fungi (3, 5 or sometimes 8)
69
Thank you for your attention
Mark Croes +32 474 681 093
Çetin Yilmaz +90 543 655 60 68
70
