HumiSeal 1B18 Acrylic Conformal Coating
Properties of HumiSeal® 1B18
Density, per ASTM D1475 0.92 ± 0.02 g/cm³
Solids Content, % by weight per Fed-Std-141, Meth. 4044 30 ± 2 %
Viscosity, per Fed-Std-141, Meth. 4287 250 ± 20 centipoise VOC 654 grams/litre Drying Time to Handle per Fed-Std-141, Meth. 4061 30 minutes Recommended Coating Thickness 25 - 75 microns
Recommended Curing Conditions 24 hrs @ RT or 2 hrs @ 76°C Time Required to Reach Optimum Properties 7 days
Recommended Thinner HumiSeal® Thinner 73
Recommended Stripper HumiSeal® Stripper 1080
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 67 ppm/°C Glass Transition Temperature - DSC 42°C
Modulus - DMA 11.1 MPa
Flammability, per UL 94 V-0
Dielectric Withstand Voltage, per MIL-I-46058C >1500 volts Dielectric Breakdown Voltage, per ASTM D149 6300 volts Dielectric Constant, at 1MHz and 25°C, per ASTM D150-98 2.6
Dissipation Factor, at 1MHz and 25°C, per ASTM D150-98 0.01
Insulation Resistance, per MIL-I-46058C 5.5 x 1014 ohms (550TΩ) Moisture Insulation Resistance, per MIL-I-46058C 7.0 x 1010 ohms (70GΩ)
Fungus Resistance, per ASTM G21 Passes
Application of HumiSeal® 1B18
Cleanliness of the substrate is of extreme importance for the successful application of a conformal coating. Surfaces must be free of moisture, dirt, wax, grease, flux residues and all other contaminants. Contamination under the coating could cause problems that may lead to assembly failures.
Depending on the complexity, density and configuration of components on the assembly, it may be necessary to reduce the viscosity of HumiSeal® 1B18 with HumiSeal® Thinner 73 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 73. Viscosity in the dip tank should be checked regularly, using a simple measuring device such as a Zahn or Ford
HumiSeal® 1B18 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 73 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® 1B18 to HumiSeal® Thinner 73 is 1:1 by volume, however the ratio may need to be adjusted to obtain a uniform coating.
HumiSeal® 1B18 may be brushed with a small addition of HumiSeal® Thinner 73. Uniformity of the film depends on component density and operator's technique.
HumiSeal® 1B18 should be stored away from excessive heat or cold, in tightly closed containers. HumiSeal®
products may be stored at temperatures of 0 to 35°C. Prior to use, allow the product to equilibrate for 24 hours at a room temperature of 18 to 32°C.
Application of HumiSeal® Conformal Coatings should be carried out in accordance with local and National Health and Safety regulations.
The solvents in HumiSeal® Conformal Coatings are flammable. Material should not be used in presence of open flame or sparks. Use only in well-ventilated areas to avoid inhalation of vapours or spray. Avoid contact with skin and eyes.
Consult MSDS/SDS prior to use.