LOCTITE EA 3943

Harmonization Code : 3214.10.00 | Putty and other mastics | Resin cements, caulking compounds and other mastics

LOCTITE EA 3943

Main features

  • Cannula-Focused Medium-Viscosity Dispensing
  • Sub-5-Second UV Fixture
  • UV-Fluorescent Assembly Inspection

Product Description

LOCTITE AA 3943 is a one-part, medium-viscosity UV and visible-light acrylic adhesive for bonding stainless-steel cannulae into hubs, syringes and lancets. Its 6,000 to 7,500 mPa s viscosity at 25 deg C is suited to dispensing on cannulae before hub assembly, including larger-gap needle configurations. The adhesive fixtures in less than 5 seconds under the stated 365 nm UV conditions and fluoresces under black light for assembly inspection. The cured material combines 271% elongation at break with Shore D 69 hardness, supporting flexible medical-device bonds across the specified glass, plastic and metal substrates.

Key features

  • Needle-assembly viscosity: 6,000 to 7,500 mPa s at 25 deg C supports controlled cannula-to-hub dispensing.
  • Fast light cure: Fixture time is less than 5 seconds at 30 mW/cm^2 and 365 nm on glass.
  • Inspection fluorescence: UV fluorescence supports visual confirmation of adhesive presence in bonded assemblies.

Applications

Applications include stainless-steel cannula bonding in hubs, syringes and lancets, plus documented glass, plastic and metal component bonding for disposable medical-device assembly.

Product Family

LOCTITE EA 3943

Loading pricing…
TDS, SDS & Technical Documents

Technical Specifications

General Properties
Appearance
Appearance at room temperature.
Transparent to hazy liquid, Free of undissolved solids
Specific Gravity
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume. For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
1.04
Physical Properties
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
6,000 to 7,500 mPa.s
Thermal Properties
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.
55 °C
Chemical Properties
Water Absorption
4.4 / 4.2 %
Mechanical Properties
Elongation
Elongation is the process of lengthening something. It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks. It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.
271 %

Additional Information

Technical properties

As-supplied properties

Typical uncured-product values at 25 deg C unless otherwise stated.

Property Value Unit Method / condition
AppearanceTransparent to hazy liquidFree of undissolved solids
UV fluorescencePositiveInspection under UV light
Specific gravity1.04At 25 deg C
Gardner color3 or lessTypical limit
Viscosity6,000 to 7,500mPa sBrookfield RVT, spindle 4, 20 rpm, 25 deg C
Technical properties

Final-state properties

Typical cured-material values after 100 mW/cm^2 at 365 nm for 30 seconds per side using an electrodeless D bulb, unless otherwise stated.

Property Value Unit Method / condition
Glass transition temperature55deg CASTM E 228
Shore hardness69Durometer DISO 868
Elongation at break271%ISO 527-3
Tensile strength24N/mm^2ISO 527-3
Tensile modulus441N/mm^2ISO 527-3
UV depth of cureAt least 1.5mm100 mW/cm^2 at 365 nm for 10 seconds, electrodeless D bulb
Block shear strength9.7N/mm^2ISO 13445, polycarbonate to polycarbonate, 100 mW/cm^2 at 365 nm for 30 seconds

Leading Brands Trust in Our Products and Services

Products that Perform| Knowledge that Serves| Service that Delivers