Epoxy Ecoat Cure Times
Why do epoxy electrocoat materials have a wide cure window in terms of temperature and time?
Q. Why do epoxy electrocoat materials have a wide cure window in terms of temperature and time? What allows this flexibility?—J.M.
A. The typical automotive epoxy electrocoat primer coating consists of an amino-epoxy resin formulated in combination with a blocked di-isocyanate crosslinker that, when baked at temperatutes greater than 170°C, polymerizes and crosslinks to form epoxy-urethane-chained structures. These estructures provide excellent mechanical, chemical and corrosion properties in a variety of combinations of film crosslinking densities and/or molecular weights.
Because the degree of epoxy-urethane crosslinking and molecular weight is directly proportional to the time and temperature of exposure of the electrocoat film during oven cure, the e-coat paint can provide good to excellent performance at multiple degrees of crosslinking. In other words, it provides a wide window of operation and provides excellent resistance under multiple overbaking or underbaking conditions.
The mechanical, physical and chemical properties of the cured film are specific to each crosslinking density’s time/temperature values during curing. Some properties improve with increased crosslinking densities and others don’t.
Related Content
-
ECOAT24 Issues Call for Speakers
Don't miss your chance to apply to speak at ECOAT24. Submit your abstract by June 26, 2023.
-
CFS Unveils New Hook Locks Parts Racking Solution
New product from Custom Fabricating & Supplies (CFS) prevents part loss during coating processes.
-
Take Full Advantage of Industry Events
As travel plans ramp up for the year, what industry events will you attend? Products Finishing offers a quick look at some of the upcoming opportunities for 2024.
