Moisture Sensitivity Of Isocyanates; Foam Resins With 245 Fa Blowing Agents; Changing Materials; A (Red) And B (Blue) Components - Graco HFR Setup And Operation Manual

Moisture Sensitivity of
Isocyanates
Isocyanates (ISO) are catalysts used in two component
foam and polyurea coatings. ISO will react with moisture
(such as humidity) to form small, hard, abrasive crystals,
which become suspended in the fluid. Eventually a film
will form on the surface and the ISO will begin to gel,
increasing in viscosity. If used, this partially cured ISO
will reduce performance and the life of all wetted parts.
NOTE: The amount of film formation and rate of crystal
lization varies depending on the blend of ISO, the
humidity, and the temperature.
To prevent exposing ISO to moisture:
• Always use a sealed container with a desiccant
dryer in the vent, or a nitrogen atmosphere. Never
store ISO in an open container.
• Keep the ISO lube pump reservoir (if installed) filled
with IsoGuard Select, part 24F516. The lubricant
creates a barrier between the ISO and the atmo
sphere.
• Use moisture-proof hoses specifically designed for
ISO, such as those supplied with your system.
• Never use reclaimed solvents, which may contain
moisture. Always keep solvent containers closed
when not in use.

A (Red) and B (Blue) Components

IMPORTANT!
Material suppliers can vary in how they refer to plural
component materials.
Be aware that when standing in front of the manifold on
proportioner:
• Component A (Red) is on the left side.
• Component B (Blue) is on the right side.
313997ZAA
• Never use solvent on one side if it has been con
taminated from the other side.
• Always lubricate threaded parts with ISO pump oil
or grease when reassembling.
Foam Resins with 245 fa
Blowing Agents
Some foam blowing agents will froth at temperatures
above 90°F (33°C) when not under pressure, especially
if agitated. To reduce frothing, minimize preheating in a
circulation system.

Changing Materials

• When changing materials, flush the equipment mul
tiple times to ensure it is thoroughly clean.
• Always clean the fluid inlet strainers after flushing.
• Check with your material manufacturer for chemical
compatibility.
• Most materials use ISO on the A (Red) side, but
some use ISO on the B (Blue) side. See the follow
ing section.
For all machines:
• The A (Red) side is intended for ISO, hardeners,
and catalysts.
• If one of the materials being used is moisture-sensi
tive, that material should always be in the A (Red)
side.
• The B (Blue) side is intended for polyols, resins, and
bases.
NOTE: For machines with material volume ratios other
than 1:1, the higher volume side is typically the B (Blue)
side.
A (Red) and B (Blue) Components
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