Moisture Sensitivity Of Isocyanates; Changing Materials - Graco XP-H Series Operation, Repair, And Parts

Important Isocyanate (ISO) Information
Moisture Sensitivity of
Isocyanates
Exposure to moisture (such as humidity) will cause ISO
to partially cure, forming small, hard, abrasive crystal
that become suspended in the fluid. Eventually a film will
form on the surface and the ISO will begin to gel,
increasing in viscosity.
Partially cured ISO will reduce performance and the
life of all wetted parts.
• 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 pump wet cup or reservoir (if
installed) filled with appropriate lubricant. The
lubricant creates a barrier between the ISO and
the atmosphere.
• Use only moisture-proof hoses compatible with
ISO.
• Never use reclaimed solvents, which may contain
moisture. Always keep solvent containers closed
when not in use.
• Always lubricate threaded parts with an
appropriate lubricant when reassembling.
NOTE: The amount of film formation and rate of
crystallization varies depending on the blend of ISO, the
humidity, and the temperature.
8
NOTICE

Changing Materials

Changing the material types used in your equipment
requires special attention to avoid equipment damage
and downtime.
• When changing materials, flush the equipment
multiple times to ensure it is thoroughly clean.
• Always clean the fluid inlet strainers after flushing.
• Check with your material manufacturer for
chemical compatibility.
• When changing between epoxies and urethanes
or polyureas, disassemble and clean all fluid
components and change hoses. Epoxies often
have amines on the B (hardener) side. Polyureas
often have amines on the B (resin) side.
NOTICE
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