Well-being through work
22.11.2012
K Jussila
1
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Working in Cold Climate – Thermal Protection by Clothing ARENA Narvik 22nd November, 2012 Kirsi Jussila, M.S. (Techn.), Research Engineer
22.11.2012
K Jussila
2
© Finnish Institute of Occupational Health
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Harsh weather creates challenges to worker Effects of harsh weather in Winter Machines, tools and vehicles
Impaired functioning Freezing
Materials and infrastructure
Damage to information and electrical network Changes in land use Damage to roads
Workers
Discomfort Lightweight and flexible clothing Slipping accidents Anti-slip and supporting footwear Decreased physical work capacity Lightweight clothing and low friction between layers Frostbites Sufficient protection Problems with traffic, patient transportation and food delivery Health problems Aggravated symptoms of diseases
© Finnish Institute of Occupational Health
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DEMANDS for protective clothing
Standards
Textiles
• Thermal insulation • Air permeability • Resistance to water penetration • Water vapour resistance
Work
Clothing and garments • Thermal insulation of clothing • Hand and feet protection
Human
Work environment
Work tasks
Thermal balance
• Temperature • Wind • Moisture and snow • Ice • Darkness
• Exposure time • Ergonomics and postures • Working place • Tools • Durability of garments
• Core and skin temperature • Sensations • Comfort
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K Jussila
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Performance
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• Level of physical activity • Dexterity
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Harsh weather creates different requirements for the protective clothing •
Clothing needs to be warm, also in changing situations •
•
Protect against moisture, such as snow and sleet •
•
but not loosing manual performance
Providing safety against external hazards •
•
but being breathable at the same time
Thermal protection of hands •
•
but not too warm to cause sweating
but being light weighted
Durable in use •
but being comfortable to wear
22.11.2012
K Jussila
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© Finnish Institute of Occupational Health
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Idea of the multilayer clothing •
Air is the best "raw material" in cold protective clothing.
clothing layers convection
•
Cold protective clothing contains: • •
radiation
20 % textile 80 % air
conduction
skin
air layers
Photo: www.joutsen.com 22.11.2012
K Jussila
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© Finnish Institute of Occupational Health
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Protective winter clothing by layers •
The under layer keeps the skin dry and warm •
•
The mid layers adjust the thermal insulation of clothing (1-3 layers). •
•
Good materials are polyester (PES), polypropylene (PP), wool (WO), silk (SE) and two-layer materials.
Good materials are wool, fleece and synthetic fur.
The outermost layer protects against cold, wind and moisture. • •
Loose fitting Visibility is enhanced by using colours and reflectors.
Clean clothing is warmer than dirty one!
22.11.2012
K Jussila
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© Finnish Institute of Occupational Health
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Protection of head, hands and feet •
Head and face protection • • • •
•
Hand protection consists of different layers. • •
•
Headgear protects against cold, wind and moisture. Should cover the ears and face. Do Not limit visibility. Compatibility with other personal protective equipment (PPE).
Thin gloves underneath and thicker ones on top. Mittens are warmer than gloves.
Feet protection consists different layers. • • • •
Two pairs of socks: thin underneath and thicker ones on top Winter shoes should be one size larger than summer shoes. A thick outsole Insulation can be increased by using insoles.
22.11.2012
K Jussila
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© Finnish Institute of Occupational Health
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IREQ, Insulation Required m²K/W 1,24
IREQ
1,09
Tsk Tcl T Tcl sk M W Eres C res E RC
0,93 0,78 0,62 0,47 0,31
Cold protective clothing (EN 342)
0,16 0
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K Jussila
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© Finnish Institute of Occupational Health
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Wind decrease thermal insulation Kokonaislämmineristävyys nuken seisoessa paikallaan Air permeable clothing, ilmaaläpäisevä päällysvaate AP 50 l/m2
Rctot(m^2K/W)
0.5
Wind proof clothing, AP 0 l/m2 ilmaaläpäisemätön päällysvaate
0.4 0.3 0.2 0.1 0.0 0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
Tuuli (m/s) Wind (m/s)
22.11.2012
K Jussila
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© Finnish Institute of Occupational Health
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Effect of clothing size, wind and ventilation on thermal insulation
22.11.2012
K Jussila
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Too high thermal insulation in relation to physical activity Lämmöneristävyyden lasku korkealla
insulation Thermal (m²K/W) Icl(m²K/W) Lämmöneristävyys,
Heavy lämmöneristävyydellä physical activity in calm atraskaassa temperature – 30 työssä tyynellä (Ta =°C -30 °C) 0,40 Lämmöneristävyys
0,35 0,30 0,25 0,20 0,15 0,10
Thermal insulation decreased about 30 %
0,05 0,00 0
15
30
45
60
75
90
105
120
Aika (min) Time (min)
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K Jussila
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Additional heating in garments If weather is extremely cold and physical activity low Personal heated garments (PHG)
electrically heating garments (power source) phase change material garments chemical heating garments of fluid/air flow heating garments
Photo: www.sievi.com
Can be applied into jackets, vests, gloves or insoles. Photo: Kirsi Jussila
K Jussila
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Phase Change Materials (PCM) • React to temperature changes • Store and release heat • Outlast® www.outlast.com
ambient conditions Outer fabric layer
Stored heat released back to skin Lining material
Phase change material layer
Skin Heat produced from body 22.11.2012
K Jussila
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Multiexposure protection • High visibility • Protection of head and face in the cold • Heat protection in cold
22.11.2012
K Jussila
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© Finnish Institute of Occupational Health
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Conclusions • Layered clothing provides best protection in the cold. • Clothing needs to be adjusted according to physical activity and ambient conditions. • In extreme cold conditions clothing solely can not provide sufficient protection, physical activity is needed. • In the future protection against multiexposures needs more research and development. 22.11.2012
K Jussila
16
© Finnish Institute of Occupational Health
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Thank You!
Contact:
[email protected] Kirsi Jussila Work
22.11.2012
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