HumiSeal 1A33

Product Specification

Density, per ASTM D1475

0.95 ± 0.02 g/cm³

Solids Content, % by weight per Fed-Std-141, Meth. 4044

44 ± 2 %

Viscosity, per Fed-Std-141, Meth. 4287

180 ± 20 centipoise

VOC

531 grams/lire

Recommended Coating Thickness

25 – 75 microns

Drying Time to Handle per Fed-Std-141, Meth. 4061

15 minutes

Optional Curing Conditions to Reach Optimum Properties

30 days at RT30 hours @ 76°C

20 hours @ 88°C

Recommended Thinner (dipping, brushing)

HumiSeal Thinner 503

Recommended Thinner (spraying)

HumiSeal Thinner 521, 521EU

Recommended Stripper

HumiSeal Stripper 1063

Shelf Life at Room Temperature, DOM

24 months

Thermal Shock, 50 cycles per MIL-I-46058C

-65° to 125°C

Coefficient of Thermal Expansion – TMA

193 ppm/°C

Glass Transition Temperature – DSC

26°C

Modulus – DMA

27.2 MPa

Flammability, per UL 94

V-0

Dielectric Withstand Voltage, per MIL-I-46058C

>1500 volts

Dielectric Breakdown Voltage, per ASTM D149

7500 volts

Dielectric Constant, at 1MHz and 25°C per ASTM D150-98

3.6

Dissipation Factor, at 1MHz and 25°C per ASTM D150-98

0.03

Insulation Resistance, per MIL-I-46058C

2.0 x 10¹⁴ohms (200TΩ)

Moisture Insulation Resistance, per MIL-I-46058C

1.6 x 10¹⁰ohms (16GΩ)

CTI, PLC per UL746A @ 600 volts

Fungus Resistance, per ASTM G21

Passes

HumiSeal 1A33 offers the following features:

Urethane chemistry

chemically resistant

single component

contains no free isocyanates

used in combination with Thinner 503/521

MIL-I-46058C qualified

RoHS directive 2015/863/EU

Recognized under UL File Number E105698

Sharp Edge Coverage

excellent moisture and environmental protection for printed circuit assemblies

fluorescence under UV light for ease of inspection

Application of HumiSeal® 1A33

For successful application of HumiSeal® 1A33 conformal coating, it is essential that the substrate is thoroughly cleaned. Surfaces must be free moisture, dirt, wax, grease, flux residues, and all other contaminants, as contamination under the coating can lead to adhesion or electrical issues, potentially causing assembly failures.

Dipping

To achieve a uniform film, it may be necessary to reduce the viscosity of HumiSeal® 1A33 with HumiSeal® Thinner 503, depending on the complexity, density, and configuration of components on the assembly. Once the optimal viscosity is determined, a controlled immersion and withdrawal rate (typically 5-15 cm/min) will ensure an even deposition of the coating. As solvent evaporates during application, viscosity will increase and should be adjusted by adding small amounts of HumiSeal® Thinner 503. Regularly check the viscosity in the dip tank using a Zahn or Ford viscosity cup.

Spraying

HumiSeal® 1A33 can be applied using conventional spraying equipment in a well-ventilated area. To achieve a uniform spray pattern and a pinhole-free film, the addition of HumiSeal® Thinner 521 or 521EU is required. The recommended ratio is 4:1 by volume, but adjustments may be necessary based on the specific spray equipment and technique.

Caution

Ensure the application of HumiSeal® Conformal Coatings follows local and national health and safety regulations. The solvents used are flammable, so do not use the product near open flames or sparks. Always apply the coating in a well-ventilated area to avoid inhaling vapors or spray. Avoid contact with skin and eyes. Consult the MSDS/SDS before use.