Polyurethane to Metal Bonding 840 One-Coat Surface Treatment
Equivalent to Chemlok 218, Cilbond 48/49, Thixon 422
Description
The Polyurethane to Metal Bonding 840 one-coat surface treatment is designed to bond castable and
millable polyurethane elastomers to metals and other rigid
substrates. It consists of a blend of polymers and resins dissolved
in an organic solvent system.
Features and Benefits
- Environmentally Resistant – provides excellent resistance to water,
salt spray, a variety of solvents and otherenvironmental
conditions.
- Convenient – requires no primer, reducing labor and costs.
Typical Properties
Appearance: Clear to Slightly Hazy Amber Liquid
Viscosity, cps @ 25°C (77°F) Brookfield LVT Spindle 3, 60 rpm:
400-1000
Density(kg/m3): 950.0 - 990.0
Solids Content by Weight, %: 18-22
Flash Point (Seta), °C: 2-3
Solvents: Toluene, Trichloroethylene, Isopropanol, Ethanol
Application
Surface Preparation – Thoroughly clean metal surfaces prior to application. Remove
protective oils, cuttingoils and greases by solvent degreasing or
alkaline cleaning. Remove rust, scale or oxide coatings by
suitablechemical or mechanical cleaning methods.
Mixing – No agitation is required before or during use. If dilution is
needed, use either a 1:1 isopropanol:toluene blend (by volume) or
glycol solvents. Note proper dilution for the various application
methodsis best achieved by experience.
Applying – Apply Polyurethane to Metal Bonding 840 by brush, dip, spray, roll coat or any method that gives uniform
coating and avoids excessive runs and tears. Regardless of
application method, dry film thickness of 840 should be 15-35
micron. 840 is also tolerant of processing conditions such as long
prebakes.
Drying/Curing – Allow coated parts to air-dry for at least 60 minutes at room
temperature for complete solvent evaporation. The film may be force
dried at higher temperatures for shorter periods of time. Drying
for 15 minutes at 121°C (250°F) has no harmful effect on
performance.
To enhance cohesive strength, bake coated inserts a minimum of 2
hours at 121°C (250°F). Large inserts will require longer baking
time at 121°C (250°F) to negate the heat sink effect.
Parts coated with Polyurethane to Metal Bonding 840 may be vulcanized immediately after air-drying.
Molding procedures that are used with heat vulcanizing urethane
elastomers can be used with 840 adhesive. The cure time and
temperature are the same as the process conditions required to
vulcanize the urethane compound being molded. Best results are
obtained with curing temperatures above 71°C (160°F).
Cleanup – Use alcohol, such as isopropanol, or a chlorinated solvent, such
as trichloroethylene, to clean up small spills.
Shelf Life/Storage
Shelf life is one year from date of shipment when stored at 21-27°C
(70-80°F) in original, unopened container. Do not store or use near
heat, sparks or open flame.
Packing
3.5kg/drum; 18kg/drum
