HumiSeal 1A33NS Urethane Conformal Coating

Harmonization Code : 3906909090 | Acrylic polymers in primary form Others>Others

Main features

Fluoresces under UV light for inspection
Low moisture vapor permeability
Fast drying to handle (15 minutes)

Product Description

HumiSeal 1A33NS is a high-performance, toluene-free polyurethane coating designed for the most demanding electronic environments. Offering a safer, isocyanate-free alternative for the workshop, it provides a robust shield against moisture and chemical contaminants. Whether for automotive sensors or military hardware, 1A33NS ensures reliable performance with the added benefit of UV traceability and UL-certified protection.

Product Key Features

Single-component polyurethane conformal coating
Toluene-free formulation
No free isocyanates
Fluoresces under UV light for inspection
Fast drying to handle (15 minutes)
Low moisture vapor permeability
RoHS Directive 2002/95/EC compliant

Applications

General printed circuit board (PCB) protection
Consumer electronics assemblies
Industrial electronics
Telecommunications equipment

Specifications
Additional Information

Technical Specifications

General Properties

Density (g)

0.95 g/cm3

Film Thickness

Film Thickness
Film thickness is the thickness of a backing film without taking into account any coatings or adhesive layers. It is measured in micron and the conversion factor to mil is 0.039.

25 - 75 µm

Solids

44 %

Physical Properties

Viscosity

Viscosity
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application

180 mPa.s

Thermal Properties

Glass Transition Temperature (Tg)

Glass Transition Temperature (Tg)
The glass transition temperature for organic adhesives is a temperature region where the polymers change from glassy and brittle to soft and rubbery. Increasing the temperature further continues the softening process as the viscosity drops too. Temperatures between the glass transition temperature and below the decomposition point of the adhesive are the best region for bonding.

The glass-transition temperature Tg of a material characterizes the range of temperatures over which this glass transition occurs.

26 °C

Operating Temperature

-65 - 125 °C

Coefficient of Thermal Expansion (CTE)
Coefficient of Thermal Expansion (CTE), α1 Coefficient of Thermal Expansion (CTE), α1 CTE α1 (alpha 1) is the slope of the Coefficient of thermal expansion in a temperature range below the Glass transition temperature (Tg). It explains how much a material will expand until it reaches Tg.	193 ppm/°C

Mechanical Properties

Storage (DMA) Modulus
Storage (DMA) Modulus @ 25°C	27.2 N/mm2

Electrical Properties

Breakdown Voltage

Breakdown Voltage
Breakdown voltage is the minimum voltage necessary to force an insulator to conduct some amount of electricity.
It is the point at which a material ceases to be an insulator and becomes a resistor that conducts electricity at some proportion of the total current.

After dielectric breakdown, the material may or may not behave as an insulator any more because of the molecular structure alteration. The current flow tend to create a localised puncture that totally alters the dielectric properties of the material.

This electrical property is thickness dependent and is the maximum amount of voltage that a dielectric material can withstand before breaking down. The breakdown voltage is calculated by multiplying the dielectric strength of the material times the thickness of the film.

7500 V

Dielectric Constant
Dielectric Constant @ 1000 kHz	3.6

Additional Information

Learn More About HumiSeal® 1A33NS

Application Methods

HumiSeal® 1A33NS can be applied using standard conformal coating techniques. Proper substrate cleanliness is essential to ensure coating performance and reliability.

Dipping: Viscosity may be adjusted using HumiSeal® Thinner 521 to achieve a uniform film. Use a controlled immersion and withdrawal rate of 5–15 cm/min. Monitor viscosity regularly using a Zahn or Ford cup.
Spraying: Apply using conventional spray equipment with adequate ventilation. A typical starting ratio is 1:1 by volume of coating to Thinner 521, adjusted as needed to achieve a pinhole-free film.
Brushing: Suitable for localized coating or repair. Film uniformity depends on component density and operator technique.

Important Notes:

Surfaces must be free of moisture, grease, flux residues, and contaminants
Viscosity should be checked regularly during application
Perform process validation prior to full production use

Application Compatibility

HumiSeal® 1A33NS is compatible with materials commonly used in electronic assemblies.

Compatible With:
✔ FR-4 and standard PCB substrates
✔ Copper, tin, nickel, and plated finishes
✔ Most electronic components
✔ Automated and manual coating equipment

Not Recommended For:
✖ Contaminated or moisture-laden substrates
✖ Use near open flames or ignition sources

Additional Guidance:
UV fluorescence enables easy inspection and verification of coating coverage. Always confirm compatibility with assembly materials and processes.

Safety and Handling Precautions ⚠️

Use only in well-ventilated areas
Avoid inhalation of vapors or spray mist
Avoid contact with skin and eyes
Keep away from sparks, heat, and open flames
Follow all local and national safety regulations

Always consult the Safety Data Sheet (SDS) before use.

Storage Recommendations 📦

Store HumiSeal® 1A33NS in tightly closed containers away from excessive heat or cold. Recommended storage temperature is 0–35°C. Allow the product to equilibrate for 24 hours at 18–32°C prior to use.