Foam Fabricating Industry Information
Foam fabricating is the manufacturing of a lightweight, versatile,
polymer-based material. The material, such as plastic or polyurethane,
is "frothed up" while in a molten state and then cooled, which fills
the material with countless little bubbles, giving it an appearance
similar to a sponge. Foam fabricators classify their product by two
categories:
open-cell foam and
closed-cell foam. Closed-cell foam contains
foam
cells which are sealed, or "closed" and from one another. This foam is
very dense and has high compressive strength. Because the cells are not
broken in this foam and gas and liquid molecules do not freely travel
from cell to cell, the cells expand when exposed to heated gas. The
expansion fills the material, making closed cell foam an excellent heat
insulator, like
spray foam.
Open-cell foams are lightweight, spongy, soft foams in which 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 and weak; as a result,
open-cell foams are commonly used for
foam padding and
foam cushions.
In addition, open cell foams are effective as sound barriers, having
about twice the sound resistance as closed cell foam. The
medical, construction, automotive, electronics and furniture industries all use foam products.
Foam fabricating services, such as
foam cutting, work with many, many types of foam for even more numerous applications. The most common foam used is
polyurethane foam, a resilient closed-cell foam that can biodegrade in direct and indirect sunlight. Typical applications for
urethane foam
include surgical scrubbers, x-ray positioning pads, EKG pads,
insulation foam, protective foam padding, flexible foam seating and
custom insulated containers.
Polyethylene foam
is a closed-cell, expanded, extruded, flexible plastic foam with
predictable shock absorbing qualities. Used mainly as a protective
packaging material, polyethylene foam is used to wrap products such as
computer components, frozen foods, furniture, signs, sporting goods and
clothing. Ethafoam is a popular polyethylene foam that offers excellent
shock absorption qualities and is often used for blocking, cushioning
and bracing protection in material handling and shipping. Polyether
foam is a low-cost polyurethane foam that provides good cushioning and
has acoustics and packaging properties. PVC foam is a closed-cell vinyl
foam that is pliable and soft and used in gasketing to prevent water
transmission. Expanded polystyrene (EPS) is being used in some
surprising applications: ladies bedroom slippers padding foam, air
conditioners` air
filter foam, home insulation foam, smokestack scrubbers filter foam, oil rigs, weather balloons and satellites.
Foam
can be made from a variety of materials including plastic, low density
elastomers and rubber. Typically formed from polymers, foam is made by
mixing a number of chemicals and adding gassing agent. The addition of
the gassing agent causes the material to expand and form a foam strip.
The foam is comprised of numerous gas bubbles trapped in the material.
After foam is formed, a variety of foam fabricating services can be
performed, including several types of foam cutting processes. Die
cutting is a common foam fabricating process, in which different shapes
are cut out of foam strips, blocks or sheets. Water jet cutting uses a
fine stream of water under ultra high pressure to perform the same
function as die cutting, but offers extremely close tolerances that die
cutting cannot achieve. Hot wire cutting utilizes a heated wire in
order to form smooth, straight cuts in the foam. There are also several
types of foam forming processes. A popular foam forming process is
thermal-forming, in which bulk foam materials are heated in order to
produce machinable shapes like foam sheets. Another forming process,
foam felting, produces denser foam materials by means of compressing
and curing thick, soft foam materials.
Foam
fabricating services produce a large amount of scrap. The first major
source of scrap is produced during foam production as well as foam die
cutting processes. Foam fabricating scrap results from the startup and
shutdown of the production line when changing run formulations and when
foam blocks are cut and shaped into the desired end product. The second
major source of foam scrap is foam products that have reached the end
of their useful life. Scrap foam has been shredded and rebonded and
then used for such things as carpet padding and filler for pillows and
furniture. In previous decades, foam fabricators have burned foam
materials. Although foam does not burn by itself, they can be forced to
burn and is considered to be non-toxic by U.S government agencies.
However, as the result of growing environmental concerns and more
stringent carbon dioxide emission regulations, many foam manufacturers
have turned to recycling foam scrap. Recycling offers manufacturers the
ability to recoup return on investment, which would be lost by burning
the scrap. Although the use of recyclable foam materials is growing,
the process of collecting the foam, separating out foam`s contaminants
and then shipping the foam in an economic manner to those foam
fabricators who utilize scrap is a significant obstacle for foam
manufacturers wanting to recycle.