LOCTITE AA 3523 UV-Curing Acrylic Adhesive for Flexible PCB, Glass and Metal Bonding

LOCTITE AA 3523 UV-Curing Acrylic Adhesive is a one-component modified-acrylate adhesive developed for rapid bonding, sealing, coating, and reinforcement in industrial production. The transparent light-to-dark amber liquid combines medium viscosity with high-speed ultraviolet curing, making it suitable for metal, glass, flexible printed circuit boards, and compatible engineering materials. Once cured, it provides excellent flexibility, toughness, vibration resistance, impact resistance, and dependable electrical insulation.

LOCTITE AA 3523 UV-Curing Acrylic Adhesive for High-Speed Assembly

LOCTITE AA 3523 UV-Curing Acrylic Adhesive requires no resin-to-hardener mixing, helping manufacturers reduce preparation time, dispensing errors, and material waste. The product cures when exposed to ultraviolet radiation at 365 nm. For complete surface cure in areas exposed to air, suitable short-wavelength radiation within the 220–260 nm range may also be required.

Its typical viscosity range is 16,000–24,000 mPa·s at 25°C. This consistency supports controlled dispensing while providing enough flow to wet bonding surfaces. It is useful for accurate adhesive placement around glass parts, metal components, flexible PCB sections, and small electronic assemblies.

Under Henkel’s specified test conditions, fixture time on glass microscope slides is eight seconds or less when exposed to a 365 nm black-light source at 6 mW/cm². Tack-free time is twenty seconds or less under a 365 nm high-pressure mercury arc source at 100 mW/cm². Actual results depend on lamp output, exposure time, bond-line depth, distance, and substrate light transmission.

Key Benefits of LOCTITE AA 3523 UV-Curing Acrylic Adhesive

LOCTITE AA 3523 UV-Curing Acrylic Adhesive cures into a tough and flexible material that can absorb vibration, impact, and movement more effectively than many rigid bonding systems. Its typical elongation at break is 218%, while typical tensile strength reaches 27 N/mm² under the stated test method.

• One-component formulation with no mixing required
• Fast ultraviolet curing for high-volume production
• Medium viscosity for controlled dispensing and reliable wetting
• Excellent flexibility and resistance to vibration and impact
• Suitable for bonding, sealing, coating, and flexible PCB reinforcement
• Typical UV cure depth of 1.9–2.4 mm under specified conditions
• Useful electrical insulation properties for electronic assemblies

The cured adhesive has a typical Shore D hardness of 70 and dielectric breakdown strength of approximately 16 kV/mm. Typical steel-pin-to-glass tensile strength is 19 N/mm² under the manufacturer’s specified UV-curing conditions. These properties support joints requiring mechanical strength and electrical protection.

Applications of LOCTITE AA 3523 UV-Curing Acrylic Adhesive

LOCTITE AA 3523 UV-Curing Acrylic Adhesive is designed for industrial bonding, sealing, and coating of metal and glass components. It is also suitable for reinforcing flexible printed circuit boards and joining compatible substrates.

Typical applications include glass-to-metal assemblies, electronic component reinforcement, flexible PCB strain relief, sensor assembly, appliance components, decorative parts, precision electrical devices, and selected protective coating operations. The adhesive helps stabilize delicate sections exposed to vibration or mechanical movement while maintaining a transparent amber appearance.

How to Apply LOCTITE AA 3523 UV-Curing Acrylic Adhesive

Clean bonding surfaces thoroughly and remove grease, oil, dust, moisture, fingerprints, and processing residue. Dispense the adhesive through equipment fitted with black feed lines because the uncured product is light sensitive. Apply a uniform amount, assemble the parts, and expose the joint to a validated UV source.

Temperature-sensitive thermoplastics may require cooling during curing. Plastic grades should also be evaluated for stress cracking before production use. When light cannot reach all areas, LOCTITE Activator 7075 may be applied to one surface as a secondary curing method. Small-gap assemblies can reach handling strength in approximately four minutes and full cure in about 72 hours.

Storage of LOCTITE AA 3523 UV-Curing Acrylic Adhesive

Store unopened containers in a dry location, ideally between 8°C and 21°C. LOCTITE AA 3523 UV-Curing Acrylic Adhesive provides rapid processing, flexible bonding, accurate dispensing, and reliable reinforcement for electronic, glass, and metal assemblies.

Explore our industrial UV-curing adhesives for additional high-speed bonding solutions.

View the official LOCTITE AA 3523 Technical Data Sheet from Henkel.

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