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LOCTITE UK 5400 Polyurethane Hardener for Industrial Assembly

LOCTITE UK 5400 Polyurethane Hardener is an isocyanate-based component used with compatible LOCTITE UK polyurethane resins to produce solvent-free, two-component adhesive and potting systems. After accurate mixing, the components react to form a hard-elastic cured material with no measurable volume change. This performance makes the system suitable for sandwich-panel production, rigid-foam bonding, industrial potting, filling, coating, and structural assembly. LOCTITE UK 5400 is the hardener component and should not be applied as a complete standalone adhesive.

The product is typically supplied as a brown, low-viscosity liquid. Henkel lists a Brookfield viscosity of approximately 250–350 mPa·s at 20°C, while paired-system technical data gives a typical density range of 1.17–1.27 g/cm³. Its low viscosity supports accurate metering and thorough mixing with the selected resin component. The exact resin grade, mixing ratio, pot life, curing time, and final properties must be taken from the technical data sheet for the approved two-component combination.

Key Benefits of LOCTITE UK 5400 Polyurethane Hardener

LOCTITE UK 5400 Polyurethane Hardener supports solvent-free polyurethane systems for bonding pretreated metals, wood, synthetic materials, ABS, and rigid foams. Depending on the selected resin, the cured adhesive can provide elastic yet bend-resistant performance, helping sandwich structures tolerate vibration, handling stress, impact, and differences in thermal expansion between dissimilar materials.

Henkel publishes LOCTITE UK 5400 with several compatible resin components, including LOCTITE UK 8103, UK 8103 B20, UK 8202, UK 8445 B45, and other specialized UK grades. Because these combinations use different ratios and processing schedules, operators must not assume that one mixing ratio applies to every system.

For example, LOCTITE UK 8103 B20 and LOCTITE UK 5400 are mixed at a resin-to-hardener ratio of 5:1 by weight or 3.7:1 by volume. The mixed system has a typical viscosity of 8,000–10,000 mPa·s, a pot life of approximately 15–25 minutes at 23°C, an initial setting time of 80–100 minutes, and a final setting time of three to four days. Published tensile-shear strength is greater than 6 MPa, with a typical service-temperature range of -40°C to 80°C.

When paired with LOCTITE UK 8202, the recommended resin-to-hardener ratio is 4:1 by weight. That system provides a typical pot life of approximately 100 minutes, a final setting time of five to seven days, tensile-shear strength above 12 MPa, and a published service range extending from -190°C to 80°C. These figures apply to the complete UK 8202/UK 5400 system rather than the hardener alone.

Applications for LOCTITE UK 5400 Polyurethane Hardener

LOCTITE UK 5400 Polyurethane Hardener is used in polyurethane systems for manufacturing sandwich panels for commercial vehicles, containers, building structures, marine components, tanks, tankers, and engineered insulation. It can support bonding between pretreated metal skins, wooden panels, plastic sheets, ABS components, and PUR, PIR, expanded-polystyrene, or other approved rigid-foam cores.

Compatible systems may also be used as potting, casting, filling, or coating compounds for industrial and electrical assemblies. Final suitability depends on the selected resin, substrate preparation, component ratio, mixed quantity, application thickness, operating temperature, moisture exposure, and required mechanical performance.

How to Use LOCTITE UK 5400 Polyurethane Hardener

Before processing LOCTITE UK 5400 Polyurethane Hardener, ensure that all substrates are clean, dry, and free from dust, oil, grease, release agents, and loose contamination. Grinding, abrasion, sandblasting, or a suitable metal primer may improve adhesion and long-term stability on certain materials.

Measure the resin and hardener according to the technical data sheet for the selected product combination. Mix carefully until the material is completely uniform and no streaks remain. Avoid introducing excessive air. Prepare only the quantity that can be applied within the specified pot life because larger batches and higher temperatures can shorten the available processing time.

Storage and Safety of LOCTITE UK 5400 Polyurethane Hardener

LOCTITE UK 5400 Polyurethane Hardener is moisture sensitive. Contact with atmospheric moisture may create foaming and weaken the finished bond line, so containers and dispensing equipment must remain tightly sealed and protected from humidity. Review the current safety data sheet and use appropriate ventilation, gloves, protective clothing, and eye protection when handling the isocyanate-based component.

For sandwich-panel production and industrial polyurethane processing, LOCTITE UK 5400 Polyurethane Hardener provides low-viscosity mixing, broad resin compatibility, solvent-free curing, and dependable hard-elastic performance when used with the correct LOCTITE UK resin. Explore our polyurethane adhesives for sandwich panels, rigid foams, metals, wood, plastics, potting, and industrial assembly.

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