| Urenthane Foam
Application |
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Urethane foam is
produced primarily for the automotive, building,
and furniture industries for use as padding,
cushioning, and insulation. Depending upon
production, urethane foam can offer different
characteristics tailored to specific applications.
It can be soft and springy for a seat cushion
or strong and durable for rigid foam insulation.
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| Industry Challenge |
| To obtain the proper characteristics,
precise amounts of polyol and isocyanate must
be blended. This reaction creates an expanding
cellular structure. By adding catalysts, blowing
agents, colorants, and other additives, manufacturers
can vary or enhance the physical properties
of the foam for their particular application. |
| The quality of the foam depends
on the mix ratio between the polyol and isocyanate.
Pumps which pulsate or cannot accurately blend
the fluids result in poor quality and uneven
product application. |
| Another concern is the viscosity
of various polyols and isocyanates. Some polyols
tend to be viscous and may contain abrasive
colorants. To thin the fluid, the polyol is
heated, or a nitrogen blanket is used to pressurize
the supply tank. Isocyanates are usually thinner
than polyols but have a tendency to crystallize
when exposed to moisture. They require the
use of a special shaft seal in the pump to
prevent this condition from occurring. |
| The Zenith Solution |
| The pump of choice for producing
urethane foam is typically a positive displacement
gear pump, which is capable of pumping high-viscosity
fluids at elevated temperatures and pressures.
This high precision pump accurately blends
polyols and isocyanates to maintain a proper
mix ratio. The smooth, pulseless output of
a Zenith pump makes application of the foam
highly consistent. These pumps use a special
flushable double lip seal to prevent the isocyanate
from crystallizing in the shaft seal. |
| Zenith precision metering pumps
are available in a wide variety of models
to handle most urethane applications requiring
accurate mixing under varying process conditions. |
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