ARALDITE® GY 191 / ARADUR® HY 177 / ARADUR® HY 226 / ARADUR® 943 / REN® HY 956

ARALDITE® GY 191 / ARADUR® HY 177 / ARADUR® HY 226 / ARADUR® 943 / REN® HY 956 can be used with a variety of different hardeners, enabling its processing characteristics and final properties to be adjusted to meet a wide range of production conditions and applications, in particularly where good impregnation is required such as electrical encapsulation of small transformers, filters, capacitors etc. done without or slightly de-gassing needed.

RTU Product Type: Encapsulating Resin System

Product End Uses: Capacitors, Electrical Encapsulation, Filters, Transformers

Chemical Family: Epoxy & Epoxy Derivatives

Composites Processing Methods: Casting, Vacuum Casting

Features: Chemical Resistant, Excellent Flow Properties, General Purpose, Good Electrical Properties, Good Impregnation Capability, Low Shrinkage, Low Viscosity, Room Temperature Curing

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Enhanced TDS

Identification & Functionality

Features & Benefits

Applications & Uses

Composites Processing Methods
Product End Uses
Processing Methods
  • Casting / Vacuum casting
  • Manually or with automatic mixing and dosing equipment
Application Information

Araldite GY 191 can be used with a variety of different hardeners, enabling its processing characteristics and final properties to be adjusted to meet a wide range of production conditions and applications, in particularly where good impregnation is required such as electrical encapsulation of small transformers, filters, capacitors etc. done without or slightly de-gassing needed.

Technical Details & Test Data

Properties
  • Excellent flow properties,
  • High proportion of filler incorporable,
  • Low shrinkage on curing,
  • Excellent electrical properties,
  • Good chemical resistance.
Casting Process

Mixing:

In preparing the casting mixture, the ARADUR hardener component is thoroughly stirred into the pre-mixed ARALDITE resin component. Brief degassing of the casting mixture under a vacuum of 5 – 10 mbar improves homogeneity and enhances the dielectric properties of the casting.

Mixing of the components can be done at room temperature, heating of the resin can lower its viscosity but will shorten the pot life.

Curing:

To determine whether crosslinking has been carried to completion and the final properties are optimal, it is necessary to carry out relevant measurements on the actual cast 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 crosslinking and thus a different glass transition temperature.

Filling of Moulds

This should always be done slowly and preferably through the lowest point of the mould, so that the air will be carried out of the mould as it is filled. With open top moulds for encapsulation, the following procedure is recommended: 

  • Slowly pour resin mixture into one corner of the mould.
  • Fill until the unit being encapsulated is covered with a thin layer of epoxy 1-2mm thick.
  • Wait until the mixture in the mould has begun to thicken and before it completely solidifies, top up with a fresh mixture.
Cured Properties
Key Value Unit Test Method Test Condition
Specific gravity 1.42 g/cm³ DIN 55990  
Glass transition temperature 65-70 °C IEC 1006

Cured for 2h/80°C + 1h/120°C

Thermal linear coefficient 84, 90, 111, 123 ppm/K DIN 53752

20-50°C, 60°C, 80°C, 90°C

Shore D hardness 80   DIN 53505  
Dielectric strength 32 kV/mm IEC 60243

2 mm plate (50 Hz) at 25°C

Thermal conductivity 0.18 W/mK ISO 8894  
Dielectric loss factor tan δ (50 Hz) 0.7 % IEC 60250

at 23°C, 50 Hz, 25°C

Dielectric constant εr (50 Hz) 3.3   IEC 60250 at 23°C, 50 Hz
Electrolytic corrosion A1   IEC 60426  
Tracking resistance CTI>600   IEC 112  
Electric strength 28 kV/mm IEC 243

20 s for 1 mm plate at 25°C

Tensile strength 8,100 psi ISO R 527:1993  
Elongation 1 % ISO R 527:1993  
Heat distortion temperature 137 °C ASTM D648  
Tensile modulus 1.3 x 10⁶ psi ISO R 527:1993  
Izod toughness 2.5 ft-lbs/in ASTM D256-90  
Dielectric constant (50 Hz) 3.6   IEC 60250 at 25°C, 50 Hz
Dielectric strength 5 kV/mm IEC 60243-1 at 25°C, 50 Hz
Volume resistivity 410 Ω·cm IEC 60093

at 25°C, 10¹³ ohm·cm

Carbon track resistance 2,000+   ASTM D-2303  
Tensile strength (Araldite® System) 8,100 psi    
Tensile strength (Bis-A Based Epoxy) 9,000 psi    
Tensile strength (Porcelain) 6,000 psi    
Flexural strength 130-136 MPa ISO 178:2001 7 days at 25°C
Flexural strength (Araldite® GY 191) 110-130 MPa ISO 178:2001

2 hours at 120°C + 2 hours at 150°C

Compressive strength 120-130 MPa ISO 604:1985 7 days at 25°C
Coefficient of linear thermal expansion 70-80 ppm/K ISO 11359-2:1999

Mean value below Tg

Water absorption 0.4 - 0.5 % ISO 62:1999

2h at 23°C after 10 days

Volume resistivity (Araldite® GY 191) 4.0 x 10¹⁵ Ω·cm IEC 60093

at 25°C, 10¹³ ohm·cm

Flexural strength (Araldite® GY 191) 152 - 181 MPa ISO 178:2001

15 min at 248°F + 2 h at 284°F

Tensile strength (Araldite® GY 191) 8990 - 10,320 psi ISO 527:1993

15 min at 248°F + 2 h at 284°F

Flexural modulus (Araldite® GY 191) 5800 - 6380 Kpsi ISO 178:2001

15 min at 248°F + 2 h at 284°F

Storage & Handling

Storage Conditions

The components have to be stored under dry conditions at 10 - 30 oC, 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 following reanalysis. Partly emptied containers should be closed tightly immediately after use. For information on waste disposal and hazardous products of decomposition in the event of fire, refer to the Material Safety Data Sheets (MSDS) for these particular products.