杜邦铁氟龙420-703涂层的详细描述：
Fact Sheet
Description
Teflon® 420-703 solvent-based primer offers superior
intercoat adhesion with PFA and FEP powders.
This primer is not recommended as a one coat.
Refer to Table 1 for physical property data.
FDA Status
Teflon® 420-703 complies with FDA regulations in
21 CFR governing components of coatings for direct
food contact when applied according to Fact Sheet
instructions. Topcoats must also comply for the
system to be FDA conforming.
Table 1
Teflon ® Primer for Powder Coatings
Typical Properties
420-703
Color Black
Weight Solids, % 30.6
Volume Solids, % 17.9
Density, lb/gal 9.5
kg/L 1.14
Coverage, m2/L* 7.1
ft2/gal* 287
Viscosity, cP 800–1600
Maximum Use Temperature **
Note: These figures are averages and may vary.
* Theoretical coverage at 25 μm (1 mil) assuming 100% spray
efficiency.
** Dependent upon Topcoat. Refer to Fact Sheet on Topcoat.
Substrates
Teflon® 420-703 primer can be used on carbon steel,
stainless steel, and aluminum substrates. Substrates
must be free of contamination and thoroughly
cleaned. To obtain maximum adhesion, gritblasting
is recommended to a profile of 4–8 μm
(0.2–0.3 mil). The primer should be applied
immediately after blasting on carbon steel to
minimize flash rusting. Refer to the Fact Sheet
on Application.
Topcoats
Teflon® 420-703 is the recommended primer for
532-5nnn, 532-7nnn, 532-8nnn, 856-Line and
857-210.
Application
1. Bring material to room temperature.
2. Mix thoroughly and filter the material through a
100-mesh stainless steel screen (0.146 mm
openings).
3. The primer is supplied ready to spray. If
further reduction is required TN-8595, a 50:50
mixture of NMP:MIBK, may be used up to
1–2% by volume.
Use conventional industrial spray equipment.
4. Apply at dry film thickness of 10–15 μm
(0.4–0.6 mil). On carbon steel, cover blast
profile for best results.
Bake
As primer for powder topcoats:
1. Spray powder directly onto wet primer, or
force dry then apply powder topcoats.
2. Bake as recommended by the Fact Sheet on
Topcoat. Note: Optimum adhesion with PFA
powder requires an initial bake of 400°C
(750°F) metal temperature.
As primer for liquid topcoats:
1. Force dry at 220°C (430°F) for 10 min.
Teflon® Primer for Powder Coatings
420-703
DuPont™ Teflon®
Industrial Coatings
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