Polyurethane
Foam
Spray foam is a chemical product created by two
materials, isocyanate and polyol resin, which react when mixed with each other
and expand up to 30-60 times its liquid volume after it is sprayed in place.
This expansion makes it useful as a specialty packing material which forms to
the shape of the product being packaged and produces a high thermal insulating
value with virtually no air infiltration.
Properties
Thermal resistance
R-value is the term given to thermal resistance
to heat flow. The higher the R-value of an insulation product, the more
effective the insulation properties. Spray polyurethane foam comes in a range
of densities and cel structure. Low density foams are referred to as Open Cel
SPF while higher density foams are referred to as Closed Cel foam. 1.8-2 pound
polyurethane foam has the highest R-value of readily available spray foam
insulation used in homes and buildings.
Polyurethane is a closed-cell foam insulation
material that initially contains a low-conductivity gas in its cells.[5] As a
result of the high thermal resistance of the gas, spray polyurethane insulation
typically has an initial R-value around R-3.4 to R-6.7 per inch.[5] In
comparison, blown fiberglass typically has an R-Value of only R-3 to R-4 per
inch.[6]
Foam insulation blocks all three forms of heat
transfer
Conductive heat transfer
The flow of thermal energy through a substance
from a higher to a lower temperature region. Foam thermoset plastics reduce
conductive heat transfer due in part to having very loose molecular bonds; In
addition the cells of the installed spray foam are either filled with air in
the case of open cell foam or 245fa in closed cell foam.
Radiant
heat transfer
The process by which heat energy in the form of
light (usually IR unless the substrate is hot enough to glow in the visible
range) is emitted more strongly by warm surfaces and absorbed by other
materials especially those of low IR reflectivity (think matte black finish).
Radiant heat transfer does not require a medium. Foam insulation materials,
such as spray foam insulation, are opaque to thermal radiation, like most solid
materials
Convective
heat transfer
Heat which is created elsewhere that is
transported by means of a fluid, such as water or in our case air. Spray foam
insulation's most important attribute is the ability to air seal creating a
custom airtight envelope within the building structure. The added benefit to
air sealing is the ability to block convective heat transfer from interior to
exterior during heating months and vice versa during cooling months, as the
heat cannot escape through gaps in the buildings envelope without the aid of
air movement from infiltration as a means of transport.
Benefits
Spray foam
insulation, like other insulation, saves on energy costs and lowers utility
bills. Studies by the US Department of Energy show that 40% of a home's energy
is lost as the result of air infiltration through walls, windows and doorways.
Buildings treated with spray foam insulation insulate as much as 50% better
than traditional insulation products.
Insulation
properly deployed can be part of a system designed to protect against moisture,
which provides the benefit of reducing the chance of harmful mold, mildew and
rotting of wood.
In addition
to building temperature and moisture control, spray foam insulation is often
used to reduce noise. Foam insulation serves as a barrier to airborne sounds,
and reduces airborne sound transfer through a building's roof, floor and walls
compared an uninsulated structure.
In the United
States, homes treated with spray foam insulation often qualify for state and
federal tax deductions.
Insulation of
all types stops a good deal of energy loss. Some types including spray foams
also seal air leaks. Insulation can also save energy in hot climates by
reducing air conditioning use
health
impacts:
pray foam
insulation is typically non-toxic only after it has cured. While curing spray
foam emits a gas that causes blurred vision and trouble breathing. Using full
face and respiratory protection while applying the product is recommended.
Isocyanates
are powerful irritants to the eyes and gastrointestinal as well as the
respiratory tracts. Direct skin contact with isocyanates can also cause marked
inflammation. Some people say that their eyes feel like they have sand in them
at the onset of problems. Some break out in a rash on their arms, chest, and
neck.
Overexposure
to isocyanates can sensitize workers, making them subject to asthma attacks if
they are exposed again. Respiratory irritation may progress to a chemical
bronchitis. Additional exposures can make the onset easier with less isocyanate
necessary to start the attack.
Sporadic
cases of hypersensitivity pneumonitis (HP) have also been reported in workers
exposed to isocyanates. The symptoms may seem like the flu, with fever, muscle
aches, and headaches. Other symptoms may include a dry cough, chest tightness,
and difficult breathing. Individuals with chronic HP often experience
progressively more difficult breathing, fatigue, and weight loss. Individuals
with acute HP typically develop symptoms 4–6 hours after exposure.
Contact ArabTronix Co. Today
Email: ArabTronix@gmail.com
Phone/Whatsapp (Egypt): 01277154931
Phone/Whatsapp (All Countries): +201277154931
Follow Arab Tronix on Social Media
Website: https://www.ArabTronix.com
Twitter: https://twitter.com/ArabTronix
Pinterest: https://www.pinterest.com/ArabTronix/
0 Comments