| Closed cell - foam has varying
degrees of hardness, depending its density. Normal closed-cell
insulation is between 2 and 3 pounds per cubic foot. It is
strong enough to stand on without any major distortion.
Most of the cells or bubbles in closed cell foam are not
broken and resemble inflated balloons piled together in
a compact configuration. This makes it strong or ridged
because the bubbles are packed tightly enough to take a lot
of pressure. All the cells are full of air and are densely
packed together to make the insulation value of the foam
as high as possible |
Open-cell The foam is soft
like a cushion or the packaging material molded inside
a plastic bag to fit a fragile object being shipped. The cell
walls, or surfaces of the bubbles, are broken and air
fills all of the spaces in the material. This makes the foam
soft or week, as if it were make of broken balloons
or soft toy rubber balls. The insulation value of this foam
is related to the insulation value of the calm air inside
the matrix of broken cells. The densities of open-cell foams
are around ½ to ¾ of a pound per cubic foot |
