1B31

HumiSeal® 1B31 is a fast drying, single component, acrylic conformal coating that provides excellent moisture and environmental protection for printed circuit assemblies. HumiSeal® 1B31 demonstrates excellent flexibility, fluoresces under UV light for ease of inspection and is easily repaired. HumiSeal® 1B31 coating is MIL-I-46058C qualified, IPC-CC-830 and RoHS Directive 2002/95/EC compliant.

Additional Resources

Other Products Associated with 1B31

Dipping
Depending on the complexity, density and configuration of components on the assembly, it may be necessary to reduce the viscosity of HumiSeal® 1B31 with HumiSeal® Thinner 503 in order to obtain a uniform film. Once optimum viscosity is determined, a controlled rate of immersion and withdrawal (5-15 cm/min) will further ensure even deposition of the coating and ultimately a uniform film. During the application, evaporation of solvent causes an increase in viscosity that should be adjusted by adding small amounts of HumiSeal® Thinner 503. Viscosity in the dip tank should be checked regularly using a simple measuring device such as a Zahn or Ford viscosity cup.

Spraying
HumiSeal® 1B31 can be sprayed using conventional spraying equipment. Spraying should be done in an environment with adequate ventilation so that the vapour and mist are carried away from the operator. The addition of HumiSeal® Thinner 521 or 521EU is necessary to ensure a uniform spray pattern resulting in pinhole-free film. The amount of thinner and spray pressure will depend on the specific type of spray equipment used and operator technique. The recommended ratio of HumiSeal® 1B31 to HumiSeal® Thinner 521or 521EU is 1:1 by volume; however the ratio may need to be adjusted to obtain a uniform coating.

Brushing
HumiSeal® 1B31 may be brushed with a small addition of HumiSeal® Thinner 503. Uniformity of the film depends on component density and operator’s technique.

Product Specification

Product Specification
Density, per ASTM D1475 0.91 ± 0.02 g/cm3
Solids Content, % by weight per Fed-Std-141, Meth. 4044 35 ± 3 %
Viscosity, per Fed-Std-141, Meth. 4287 200 ± 15 centipoise
VOC 592 grams/litre
Drying Time to Handle per Fed-Std-141, Meth. 4061 10 minutes
Recommended Coating Thickness 25 – 75 microns
Recommended Curing Conditions 24 hrs @ RT or 30 min @ 76°C
Time Required to Reach Optimum Properties 7 days
Recommended Thinner (dipping & brushing) HumiSeal Thinner 503
Recommended Thinner (spraying) HumiSeal Thinner 521, 521EU
Recommended Stripper Stripper 1080, 1080EU
Shelf Life at Room Temperature, DOM 24 months
Thermal Shock, 50 cycles per MIL-I-46058C -65°C to 125°C
Coefficient of Thermal Expansion – TMA 170 ppm/°C below Tg340 ppm/°C above Tg
Glass Transition Temperature – DSC 14°C
Modulus – DMA 2000 MPa @ -40°C1050 MPa @ 20°C8.5 MPa @ 60°C
Flammability, per MIL-I-46058C Self-Extinguishing
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 2.5
Dissipation Factor, at 1MHz and 25°C per ASTM D150-98 0.01
Insulation Resistance, per MIL-I-46058C 8.0 x 1014 ohms (800TΩ)
Moisture Insulation Resistance, per MIL-I-46058C 6.0 x 1010 ohms (60GΩ)
Fungus Resistance, per ASTM G21 Passes