Polyester
TGIC coatings utilize the epoxy functional crosslinker TGIC
(triglycidyl isocyanurate). Use of this
low molecular weight, multifunctional crosslinker enables polyester TGIC formulations
to contain 90% or greater resin within the binder system. Weathering
of polyester TGIC powders is comparable to polyester urethane coatings.
Polyester TGIC coatings typically offer faster or lower temperature curing than
polyurethanes. Unlike urethane coatings, TGIC's maintain excellent mechanical properties at
film builds above 3 mils with no outgassing. Additionally, TGIC coatings provide superior edge coverage when sharp edges
are present.
Typical applications for polyester TGIC coatings include aluminum extrusions,
automotive wheels, transformers, air conditioners, fencing, lawn and garden
equipment, and gas cylinders.
| Pretreatment |
Iron phosphate, zinc phosphate |
Advantages: |
Excellent gloss retention |
| Application
Conditions |
Electrostatic powder spray |
|
Excellent overbake color stability |
|
40 - 100KV |
|
Good mechanical properties at high film build |
| Film
Thickness |
1.5 - 20.0 mils |
|
Good salt spray resistance |
| Specific
Gravity |
1.2 - 1.8 |
|
Wide range of colors |
| Coverage |
107.0-160.0 sq. ft./lb. per mil of coating |
|
Releases minimal volatiles upon curing |
| Baking
Schedules |
5
minutes at 410° F |
Disadvantages: |
Difficult to get low gloss finish |
| (Standard
Cure / |
7
minutes at 399° F |
|
Difficult to get very smooth coating at low film build |
| Metal
Temperature) |
15
minutes at 375° F |
|
Less solvent resistant than urethane |
TGIC Standard Cure Schedules
The data below is based on 20-gauge steel panels. For
heavier ware, higher temperatures or longer oven times may be necessary. Low
Gloss or textured finishes may require a slightly longer cure.
|
