ARALDITE® CY 221 / ARADUR® HY 2966-2

ARALDITE® CY 221 / ARADUR® HY 2966-2 is a low-viscosity, unfilled epoxy casting resin system that cures at room temperature. It allows high filler addition and is used for encapsulating or potting low voltage and electronic components.

RTU Product Type: Casting Resin

Product End Uses: Electronic Components

Chemical Family: Epoxy & Epoxy Derivatives

Composites Processing Methods: Encapsulation, Potting, Vacuum Casting

Features: Chemical Degradation Resistant, Crack Resistant, Good Atmospheric Chemical Resistance, Good Atmospheric Degradation Resistance, Heat Resistance

Enhanced TDS

Identification & Functionality

Features & Benefits

Ready-to-Use Product Features
Key Properties
  • Good heat resistance.
  • Good resistance to atmospheric and chemical degradation.
  • Good crack resistance.
  • Flammability: UL 94 HB (6 mm).

Applications & Uses

Composites Processing Methods
Product End Uses
Mixing Ratio

Measure (by weight or volume) the Araldite resin and the hardener. Add the hardener to the Araldite resin; making sure that the required amount of hardener is transferred to the resin. Stir thoroughly until mixing is complete.
Air entrainment during mixing results in pores in the cured resin. Mixing under vacuum or in a metering-mixing machine is the most effective way to prevent air entrainment. Alternatively, the static resin – hardener mixture may be de-aerated in a vacuum chamber – allowing at least 200 % ullage for the foam to expand.

Properties

Flame Rating

Regulatory & Compliance

Certifications & Compliance

Technical Details & Test Data

Processing Guidelines

Gel Time, Viscosity and Curing

Property Value Unit Condition
Mix Viscosity 700 mPa·s at 25°C
Mix Viscosity 205 mPa·s at 40°C
Pot Life 110 min

at 25°C, Time to reach 15,000 mPa·s

Pot Life 65 min

at 40°C, Time to reach 15,000 mPa·s

Gel Time 190 min

at 25°C, Gelnorm

Gel Time 50 min

at 45°C, Gelnorm

Gel Time 11 min

at 60°C, Gelnorm

Minimum Curing Cycle 24 - 48 hours

24 - 48 hours at RT or 4h at RT + 4h at 60°C

 

Mixing

Measure (by weight or volume) the Araldite resin and the hardener. Add the hardener to the Araldite resin; making sure that the required amount of hardener is transferred to the resin. Stir thoroughly until mixing is complete. Air entrainment during mixing results in pores in the cured resin. Mixing under vacuum or in a metering-mixing machine is the most effective way to prevent air entrainment. Alternatively, the static resin – hardener mixture may be de-aerated in a vacuum chamber – allowing at least 200 % ullage for the foam to expand.

Curing

  • The chemical reaction initiated by mixing resin and hardener results in the generation of exothermic heat. The peak temperatures attained are determined by the starting temperature and the size and shape of the casting. Unfilled resin systems are suitable only for manufacturing castings weighing up to about 500 grams. Mineral filler should be added to dissipate heat and damp the exothermic reaction when producing large castings.
  • There is very little exothermic reaction when producing very small castings or thin layers as the heat generated is rapidly dissipated. Cure is consequently delayed, and the surfaces of castings may remain tacky. In such cases an infrared heater or oven at 40°C – 60°C should be used to effect full cure.
  • When casting thick sections special care is needed to avoid excessive exothermic temperature rise. Short high-temperature curing schedules should not be used unless preliminary trials with castings manufactured to the specific design, and in the specified molds, produce no unacceptable exothermic effects.
  • To determine whether cross-linking has been carried to completion and the final properties are optimal, it is necessary to carry out relevant measurements on the actual object or to measure the glass transition temperature. Different gel and cure cycles in the customer’s manufacturing process could lead to a different degree of cross- linking and thus a different glass transition temperature.
Properties

Mechanical and Physical Properties

 

Property Value Unit Test Method Condition
Glass Transition Temperature 30 °C ISO 6721

Cured for 6 hours at RT + 6 hours at 60°C

Thermal Class B - IEC 60085

Cured for 6 hours at RT + 6 hours at 60°C

Storage Modulus (G’) 79 MPa ISO 6721

Cured for 6 hours at RT + 6 hours at 60°C

Tensile Modulus 20 MPa ISO 527

Cured for 6 hours at RT + 6 hours at 60°C

Tensile Strength 10 MPa ISO 527

Cured for 6 hours at RT + 6 hours at 60°C

Elongation at Break 65 % ISO 527

Cured for 6 hours at RT + 6 hours at 60°C

Thermal Conductivity 0.2 W/m·K ISO 8894-1

Cured for 6 hours at RT + 6 hours at 60°C

Hardness 37 Shore D DIN 53505

Cured for 6 hours at RT + 6 hours at 60°C

Flammability HB (6mm) - UL 94 NC E96722
Water Absorption (1 day at 23°C) 0.63 % by wt. ISO 62

Cured for 6 hours at RT + 6 hours at 60°C

Water Absorption (10 days at 23°C) 1.87 % by wt. ISO 62

Cured for 6 hours at RT + 6 hours at 60°C

Water Absorption (30 min at 100°C) 1.45 % by wt. ISO 62

Cured for 6 hours at RT + 6 hours at 60°C

 

Electrical Properties

 

Property Value Unit Test Method Condition
Dielectric Strength (2 mm specimen) 48 kV/mm IEC 60243-1

Cured for 6 hours at RT + 6 hours at 60°C

Dielectric Loss Factor (tan δ, 50Hz, 25°C) 7.5 % IEC 60250

Cured for 6 hours at RT + 6 hours at 60°C

Dielectric Constant (εr, 50Hz, 25°C) 5.75 - IEC 60250

Cured for 6 hours at RT + 6 hours at 60°C

Volume Resistivity (ρ, 25°C) 2.7 × 10¹³ Ω·cm IEC 60093

Cured for 6 hours at RT + 6 hours at 60°C

Comparative Tracking Index (CTI) > 600 - IEC 60112

Cured for 6 hours at RT + 6 hours at 60°C

Electrolytic Corrosion A1 grade IEC 60426

Cured for 6 hours at RT + 6 hours at 60°C

Curing
  • The chemical reaction initiated by mixing resin and hardener results in the generation of exothermic heat. The peak temperatures attained are determined by the starting temperature and the size and shape of the casting.
  • Unfilled resin systems are suitable only for manufacturing castings weighing up to about 500 grams. Mineral filler should be added to dissipate heat and damp the exothermic reaction when producing large castings.
  • There is very little exothermic reaction when producing very small castings or thin layers as the heat generated is rapidly dissipated. Cure is consequently delayed, and the surfaces of castings may remain tacky. In such cases an infrared heater or oven at 40°C - 60°C should be used to effect full cure.
  • When casting thick sections special care is needed to avoid excessive exothermic temperature rise.
  • Short high-temperature curing schedules should not be used unless preliminary trials with castings manufactured to the specific design, and in the specified molds, produce no unacceptable exothermic effects.
  • To determine whether cross-linking has been carried to completion and the final properties are optimal, it is necessary to carry out relevant measurements on the actual object or to measure the glass transition temperature. Different gel and cure cycles in the customer’s manufacturing process could lead to a different degree of cross-linking and thus a different glass transition temperature.

Storage & Handling

Storage Conditions

Store the components in a dry place according to the storage conditions stated on the label in tightly sealed original containers. Under these conditions, the shelf life will correspond to the expiry date stated on the label. After this date, the product may be processed only after reanalysis. Partly emptied containers should be tightly closed immediately after use.