HumiSeal 1A33LTX Urethane Conformal Coating

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

Main features

Fluoresces under UV light for easy inspection and rework
Available in pre-blended viscosities for immediate use
Easy application using automated coating systems

Product Description

HumiSeal 1A33 LTX is a high-solids, single-component polyurethane conformal coating engineered for maximum reliability in demanding environments. 1A33 LTX provides the best protection of the 1A33 series—offering superior resistance to moisture, dirt, and corrosion—while meeting modern environmental mandates such as GB30981-2020.

Product Key Features

Reliable protection against moisture, salt spray, corrosive environments, and dirt
Low moisture vapor permeability for long-term electrical reliability
Fluoresces under UV light for easy inspection and rework
Easy application using automated coating systems
Available in pre-blended viscosities for immediate use
No free isocyanates
Fully compliant with GB30981-2020 VOC requirements

Applications

Printed circuit boards (PCBs)
Automotive electronics
Industrial control systems
Consumer electronics
Power supplies and converters
Electronic assemblies exposed to harsh or corrosive environments

Specifications
Additional Information

Technical Specifications

General Properties

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

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

065 - +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 @ 25 ˚C/1000 kHz	3.6

Dissipation Factor
Dissipation Factor @ 25°C /1000 kHz	0.03

Additional Information

Application Methods

HumiSeal® 1A33 LTX pre-blended products are supplied at controlled viscosities and are ready for immediate use, requiring no additional dilution. Customers should select the appropriate pre-blend based on their coating equipment and application method prior to production use.

Cleanliness of the substrate is critical for successful conformal coating application. PCB surfaces must be free of moisture, dust, wax, grease, flux residues, and other contaminants. Contamination beneath the coating may lead to adhesion failure or reduced long-term reliability.

Application Compatibility

HumiSeal® 1A33 LTX is compatible with automated selective coating systems, spray coating, and dipping processes commonly used in electronics manufacturing. The coating fluoresces under UV light, enabling fast visual inspection, coverage verification, and straightforward repair when required.

Safety and Handling Precautions ⚠️

Application of HumiSeal® conformal coatings must be carried out in accordance with local and national health and safety regulations. The solvents contained in this product are flammable and should not be used near open flames, sparks, or other ignition sources.

Use only in well-ventilated areas to prevent inhalation of vapors or spray mist. Avoid contact with skin and eyes. Always consult the Safety Data Sheet (SDS) before use.

Storage Recommendations 📦

Store HumiSeal® 1A33 LTX and its pre-blended products in tightly closed containers, protected from excessive heat or cold. Recommended storage temperature is between 0°C and 35°C.

Prior to use, allow the product to equilibrate for 24 hours at a room temperature between 18°C and 32°C.