Superior Glove Winter Webinar

Your Guide To
Insulation and Winter
Work Glove Selection

Bios
Bill Soellner, US Sales Manager
Superior Glove Works Ltd.
• 24 years in the safety industry, having
worked for four major manufacturers
and a major safety specialty industrial
distributor
• Bill has held positions in sales, sales
management and product
management with special emphasis
on hand and arm protection.
• Bill has been published in leading
trade publications such as ISHN,
Cleanrooms Magazine and
Compliance Magazine, writing articles
on proper glove selection, clean
environments products and chemical
glove selection.
• He holds a BA from
Western Michigan University.
Ken Cox, Lead Specialist Technical
3M Home Care Division
• Ken has worked at 3M (St. Paul,
Minn.) for 40 years, of which he has
spent 29 years in the non-woven
insulation products related field.
• He holds a BS in Chemical Engineering
from Purdue University and an MBA
from the University of St. Thomas
(St. Paul, Minn.).
• He is currently a member of both the
American Apparel and Footwear
Association and the American
Association of Textile Chemists
and Colorists.

History and Basic Understanding
©3M 2014. All right reserved.

History of “Warmth”
Ancient ways of keeping warm:
• Bulky clothing
• Wrappings around hands, arms, legs
• Sleeping above / with livestock
• Furs / Skins
• Avoiding “out-in-the-open”
• Caves (fairly constant underground temp)
The month of February in the Limburg Brothers'
Très Riches Heures du Duc de Berry

Human Body “Warmth”
• Human Metabolism acts as a “furnace” to generate needed heat.
• Heat “flows” from higher temperature to lower temperature.
• At temperatures higher than the body, excess heat
needs to be released
• Sweating
• Less Clothing
• Lower the metabolism
• At cold environmental temperatures, heat needs
to be retained
• Additional clothing
• Higher metabolism
• Increased Insulation

Human Body “Warmth”
Mechanisms of Heat Loss
• Respiration & Perspiration
• Convection
• Forced
• Natural
• Conduction
• Through confined air
• Through, or along, a solid material (e.g., fiber, yarn, etc.)
• Radiation
• Surface-to-environment
• Surface-to-surface
Insulation helps control these losses.

What is Insulation?
• Anything that is a poor transmitter of heat
(low thermal conductivity)
• Anything with a high thermal resistance
• Anything that impedes the flow of
thermal energy

What are the Risks to Choosing
Inadequate Protection?

Cold Stress
Hypothermia
• Normal body temperature
(98.6°F) drops to 95°F or less.
• Mild Symptoms: alert but
shivering.
• Moderate to Severe
Symptoms: shivering stops;
confusion; slurred speech;
heart rate/breathing slow; loss
of consciousness; death.
Frostbite
• Body tissues freeze, e.g., hands
and feet. Can occur at
temperatures above freezing.
Symptoms: numbness, reddened
skin develops gray/white patches,
feels firm/hard, and may blister.
Trench Foot
• Non-freezing injury to the foot,
caused by lengthy exposure to
wet and cold environment.
• Symptoms: redness, swelling,
numbness, and blisters.
Cold temperatures and increased wind speed (wind chill) cause heat to
leave the body more quickly, putting workers at risk of cold stress.

Loss of Productivity
• Slowed Productivity
• Inaccurate & Incomplete Work
• Lost time injuries from above conditions

Understanding Warmth
Through CLO

Terminology
• “Clo Value” is a unit of thermal resistance
used in describing the insulation of clothing
ensembles
• Analogous to the thermal resistance unit of
“R value” used in describing the insulation
of houses and buildings
• 1.14 R value = 1.0 Clo value
• Coined during Research leading up to
WW II on keeping soldiers warm
(ref: Science Vol 94, No 2445,
Nov 7, 1941)
• Metabolic Rates are measured in terms of the
MET unit (see next slide)

Insulation Terms: Clo & MET values
• 1 Clo is the amount of thermal insulation required
in clothing for a man to be comfortable in a:
• normally ventilated room at,
• 70°F (21°C) and
• <50% Humidity in a,
• sitting/resting position
• The metabolic rate associated with this activity
has been defined as 1 MET
• 1 MET = 58.15 W/m²
• 1 MET = 50 Kcal/hr/m²

Clo & MET values
General Relationships:
• The colder the environment, a greater amount
of “Clo” or clothing insulation will be required
for comfort at the same level of activity
(or MET)
• The higher the metabolic rate (MET) of a
person, a lesser amount of “Clo” or
clothing insulation will be required for
thermal comfort at the same level of
environmental temperature

Normal Clo Values
NUDE PERSON
Clo = 0.0
BUSINESS SUIT
Clo = 1.0

General Rules of Insulation
• Insulation is approximately additive (but not exactly – Thermal Manikin
testing would be necessary to be more exact)
• Humans are unique individuals, therefore, differences in
insulation needs will occur for:
• Gender
• Age
• General / basal metabolic rate
• Activity level / specific metabolic rate
• Environmental conditions
• temperature
• wind velocity
• humidity
• radiant exchange with surroundings
• Duration of exposure

Clo – How Much Do You Need?
EXAMPLE:
• Workers are doing Light Work (e.g. Ice
Fishing, Driving Tractor, Walking 2 mph)
• Need to work at -10°F
• With 2 Clo worth of clothing, they’ll be
comfortable for about 1 hr, 15 min
• With an additional 0.5 Clo (2.5 Clo), they’ll
be comfortable for about 2 hrs, 45 min
• More than doubling their “allowable”
time outside
• Potentially increasing productivity
• Thinsulate™ Insulation can often provide
at least 0.5 more clo than current
work-wear insulations
DLEneutral vs Ambient Temperature
@ Activity Level: Light Work [2 MET = 116.4 W/m² °K]
-50
-40
-30
-20
-10
0
10
20
30
40
50
0 1 2 3 4 5 6 7 8 9
Duration Limit Exposure, DLEneutral, Hrs.
AmbientTemperature,°F
1. Clo
1.5 Clo
2. Clo
2.5 Clo
3. Clo
Clo Value is that of garment alone, but Duration lines
assume 0.7 Clo for ancillary clothing
Light Work
The same example of clothing ensembles, but at 0°exposure rather
than at -10 exposure, would more than Quadruple their time
outside, going from 2 hours to much more than 8 hours!

Warm Fabrics & Layers of
Warmth/Insulation

How material choices help achieve
warmth in a Winter Work Glove
A well designed glove has 3 layers: the outer-layer of the glove, the middle
insulating layer, and the inner, next to hand layer.
Outer layer: Should be of a material or combination
of materials with high abrasion resistance, water
and wind repellence, cut resistance, good grip, etc.
In the correct proportion to what work you are
going to be doing.
Middle layer: An insulating layer. Something with
high loft, that traps a lot of air, for warmth.
Inner layer: A next to skin layer, that ideally is
moisture wicking and soft against the skin.

3M™ Thinsulate™ Insulation

How does 3M™ Thinsulate
Insulation function?
Fibrous Structure Traps Air
• Low Thermal Conductivity gas
• Air is a good insulator = impedes conductive
heat loss
• The thicker (bulkier) an insulation, the
more air entrained (many insulations ONLY
depend on this mechanism)
• 3M™ Thinsulate™ Insulation for hand wear is
between 97% and 99.5% air

Fibrous Structure Helps Block Radiant Heat Loss
• A major heat loss mechanism; Fibers impede radiant heat loss
• The smaller the fiber diameters used, the more fibers per
insulation weight and the more “opaque” an insulation
• 3M™ Thinsulate™ Insulation for apparel employs microfibers
(< 10µm) and/or fine fibers
(< 15µm) coupled with larger fibers
• Analogous to radiation from fireplace –
where the chain-mail
screen blocks a large amount of the radiation
• Like fibers block radiation heat loss from the body

Thermal energy is blocked by microfibers or fine fibers
Can you read the text under
the insulation?
70 g/m² - TYPE CS

Thermal energy is blocked by microfibers or fine fibers
Can you read the text under
the insulation?
70 g/m² - TYPE CS 70 g/m² - GENERIC FIBERFIL

What To Look For/What To Avoid
When Selecting Winter Gloves

What To Look For & Avoid
If you are looking for a good winter work glove, consider
the following:
• Fully Sock Lined
• CLO knowledge and understanding values
• High Loft Insulation – like 3M™ Thinsulate ™
• Palm coating and/or liner if some water is a threat
• Full coating if immersed in water
• Good Fit – tight gloves reduce circulation and make your hands colder
• NO cotton linings
• NO compression palm if handling cold material
• Appropriate cuffs - be sure the cuff fits over your jacket or parka sleeve
• Wind protection

Advertised winter glove. Cotton napped fabric lining
@ 240 gsm.
In most cases, the lining will not cover the sides of the fingers.
Remember you lose most of the heat in your hands through the
fingers, and only insulating the front and back, but not the sides, is
a recipe for cold hands.

This picture shows a very well
designed and constructed glove with a
high CLO value ( 1.19 ). The glove
shows up as almost all purples and
blues, with NO reds and very little
yellow. So no thick spots in the lining,
and the glove is well sewn and
constructed.
A very good manufacturer of winter gloves will use Thermal imaging to show
the weak spots of their glove construction, and work to improve them.
This glove from a different manufacturer
shows a similar style glove, but with some
manufacturing issues. Note the parts of
the glove with heat loss ( the red and
yellow areas ). There is a major problem
on the thumb. The red portion on the back
of the thumb suggests a very thin spot on
the lining.

Battle of Warmth vs. Dexterity

Offers great warmth but
little dexterity.
Better dexterity but still not
great for warmth.
Thicker, more layers = less dexterity
More warmth and
better dexterity.

Great dexterity and impact
protection but not great
for warmth.
Waterproof, windproof and dexterous
but not great for warmth.
Great dexterity, grip and cut-resistance
but not great for warmth.
More dexterity = less insulation

Measuring Warmth
Fabric weight or density is one indicator of how warm
the material is going to be. This is measured in ounces
per square yard or grams per square meter. Shortened
to oz/sq yd and gsm.
Convert from oz per sq yard to the metric gsm.
Just multiply by 33.9.
So if you wanted to figure out the total lining weight
of a glove that was quoted as having a 6 oz napped
polyester lining with a 100 gram Thinsulate lining, the
total lining weight would be -
(6 x 33.9) + 100 grams = 303.4 gsm
What is going to be warmer, a glove with a 6 oz fleece
cotton lining or a 180 gsm lining?
Answer: the 6 oz is 203 gsm so it will be warmer.

Superior Glove Winter Webinar

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