Moisture Sensitivity of Isocyanates
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.
The amount of film formation and rate of crystallization 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.
•Use
•Never use reclaimed solvents, which may contain moisture. Always keep solvent containers closed when not in use.
•Never use solvent on one side if it has been contaminated from the other side.
•Always lubricate threaded parts with Part 217374 ISO pump oil or grease when reassembling.
Isocyanate Hazard
Read material manufacturer’s warnings and material MSDS to know the specific hazards of isocyanates. Use equipment in a
Foam Self-Ignition
Some materials may become
Keep Components A and B Separate
CAUTION
To prevent
Changing Materials
•When changing materials, flush the equipment multiple times to ensure it is thoroughly clean.
•Check with your material manufacturer for chemical compatibility.
•Some materials use catalyst on the A side, but some applications may use catalyst on the B side.
•Epoxies often have amines on the B (catalyst) side. Polyurethanes often have amines on the B (resin) side.
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