Henkel LOCTITE 4310 Light Cure Instant Adhesive for Medical Device Assembly

LOCTITE 4310 Light Cure Instant Adhesive Performance

LOCTITE 4310 is based on ethyl cyanoacrylate technology with an added photoinitiator. The uncured adhesive appears transparent and may range from light yellow-green to dark blue-green. It fluoresces positively under ultraviolet light, allowing operators and automated inspection systems to verify adhesive placement and coverage during quality-control procedures.

The product has a typical specific gravity of approximately 1.06 and a viscosity range of about 100 to 250 mPa·s. Henkel’s current product page lists a representative viscosity of approximately 180 mPa·s. This low-viscosity profile supports controlled flow through narrow joints, detailed component interfaces, cannula hubs, plastic fittings, and accurately matched assemblies. The maximum published gap-filling capability is approximately 0.15 mm, although thin and closely fitted bond lines generally provide faster curing and more consistent strength.

LOCTITE 4310 Light Cure Instant Adhesive Dual-Cure Technology

The primary curing mechanism uses ultraviolet or visible light. Exposed adhesive fillets and surface residues can be flash cured within seconds when they receive suitable light intensity and wavelength. Henkel reports tack-free surface times of no more than approximately five to ten seconds under several validated UV or visible-light systems. Actual curing speed depends on lamp type, wavelength, intensity at the adhesive, exposure duration, distance, substrate transmission, adhesive thickness, and joint geometry.

Humidity provides the secondary curing mechanism. Adhesive confined between closely fitted components can therefore cure even where direct light exposure is limited. Under Henkel’s non-light-curing reference conditions at approximately 22°C and 50% relative humidity, fixture time is less than five seconds on ABS, five to fifteen seconds on grit-blasted aluminum, ten to twenty seconds on polycarbonate, and twenty to thirty seconds on degreased steel.

This combination helps manufacturers flash cure visible adhesive around the joint while allowing material inside the assembly to continue curing through surface moisture. It also offers an alternative to solvent-based cyanoacrylate accelerators when rapid fillet or surface curing is required.

Medical, Plastic, Rubber, and Metal Applications

LOCTITE 4310 Light Cure Instant Adhesive is suitable for disposable medical-device components, plastic-to-metal joints, elastomer assemblies, transparent housings, needle and cannula assemblies, diagnostic components, fluid-handling parts, electronic devices, and other precision products. Compatible substrates include polycarbonate, acrylic, ABS, PVC, aluminum, steel, neoprene, and other evaluated plastics, rubbers, and metals.

The product has been tested according to Henkel protocols based on ISO 10993 biocompatibility standards to assist manufacturers with material selection for medical-device applications. This testing does not qualify the completed medical device automatically. Manufacturers remain responsible for evaluating the finished assembly according to its intended biological contact, sterilization method, production process, regulatory market, and risk-management requirements.

7 Benefits of LOCTITE 4310 Light Cure Instant Adhesive

• Dual-cure technology: Combines rapid UV or visible-light curing with secondary humidity curing.
• Low-bloom formulation: Helps reduce visible white residue around cosmetic and transparent joints.
• Rapid surface cure: Produces tack-free exposed adhesive within seconds under suitable light.
• Fluorescent inspection: Supports manual and automated quality-control verification under UV light.
• Low-viscosity flow: Reaches narrow gaps and accurately fitted precision components.
• Broad substrate compatibility: Bonds compatible plastics, elastomers, aluminum, steel, and other metals.
• One-component processing: Requires no weighing, mixing, heating, or separate hardener.

LOCTITE 4310 Light Cure Instant Adhesive Strength

After light curing under Henkel’s stated laboratory conditions, published block-shear strength reaches approximately 14.4 N/mm² on acrylic-to-acrylic assemblies, 22 N/mm² on polycarbonate-to-polycarbonate assemblies, and 12 N/mm² on polycarbonate bonded to grit-blasted steel. Non-light-cured grit-blasted steel joints develop approximately 20.4 N/mm² lap-shear strength after 24 hours at 22°C.

Typical cured physical properties include tensile strength of approximately 50 N/mm², tensile modulus of about 1,950 N/mm², elongation at break of approximately 7.3%, Shore D hardness near 84, and a glass-transition temperature around 102°C. The official product page lists an operating-temperature range of approximately -40°C to 100°C.

These figures are representative laboratory values rather than guaranteed finished-assembly specifications. Actual performance depends on substrate grade, surface condition, bond gap, curing energy, humidity, joint design, loading direction, sterilization, chemical exposure, and operating environment.

Application and Light-Curing Guidance

Clean all bonding surfaces and remove grease, oil, dust, moisture, oxidation, release agents, fingerprints, and loose contamination. Apply a controlled quantity to one surface, assemble the components promptly, and prevent movement until adequate fixture strength develops. Excessive adhesive can increase cure time and make complete light exposure more difficult.

Protect uncured LOCTITE 4310 from daylight, ultraviolet light, and strong artificial lighting during storage, dispensing, and equipment setup. Use light-resistant feed lines and reservoirs where appropriate. Validate the curing process with a calibrated radiometer and record the wavelength, intensity, exposure time, lamp distance, component orientation, and adhesive depth.

Polyethylene and polypropylene normally require surface treatment or an approved primer. Henkel reports faster humidity-cure fixture on polyethylene after treatment with LOCTITE SF 770, while plasma treatment can improve bonding performance on selected polyolefin components. Complete compatibility and aging tests should be performed with the actual production resin.

Sterilization, Storage, and Official Product Resources

Henkel’s technical data includes reference testing of needle assemblies after gamma radiation, ethylene oxide treatment, and autoclave cycles. These results are application-specific and do not establish universal sterilization compatibility. Finished medical assemblies should be tested using the intended substrate, bond geometry, sterilization dose, number of cycles, packaging configuration, and storage conditions.

Store unopened containers in a dry location between 2°C and 8°C. Keep the package protected from light and contamination, and do not return dispensed adhesive to the original bottle. Current Henkel listings include 1 oz and 1 lb package options, subject to regional availability.

Review the official Henkel LOCTITE 4310 product page and the official LOCTITE 4310 technical data sheet for current curing data, medical-device guidance, safety documents, and package availability.

Explore our light curing instant adhesives for additional rapid, low-bloom assembly materials. Browse our medical device adhesives for disposable devices, needle assemblies, diagnostic components, plastic housings, and precision bonding.