ARALDITE® CY 5948 / ARADUR® HY 926 / Silica Flour

• High fillerpossible due to low initial mix viscosity
• Long pot-life up to 80°C
• Good mechanical and electrical properties
• Good crack resistance
• Very good thermal endurance properties
• UL 746 B recognition for 200°C service temperature. Additional hardeners HY 925 and HY 925-1 available for different reactivities.

Long pot life is desirable in the processing of any casting and impregnating resin system. Mix all of the components together very thoroughly at room temperature or slightly above and under vacuum. Proper mixing will result in homogenous mixture with uniform reactivity.

For the mixing of medium to high viscous casting resin systems and for mixing at lower temperatures, we recommend special thin film degassing mixers. For this low viscous impregnating resin systems, conventional anchor mixers are usually sufficient.

In larger plants, two premixers are used to mix the individual components (resin, hardener) with the respective quantities of additives (if used) under vacuum. Metering pumps then feed these premixes to the final mixer or a continuous mixer. The individual premixes can be stored at elevated temperature (about 60°C) for up to about 1 week, de-pending on formulation.

Mixing time can vary from 0.5 to 3 hours, depending on mixing temperature, quantity, mixing equipment and the particular application. The required vacuum is 0.5 to 8 mbar. The vapour pressure of the individual components should be taken into account.

The effective pot-life of the mix is about > 2 days at temperatures below 25°C. Conventional batch mixers should be cleaned once a week or at the end of work. For longer interruptions of work, the pipes of the mixing and metering installations have to be cooled and cleaned with the resin component to prevent sedimentation and/or undesired viscosity increase. Interruptions over a weekend (approx. 48h) without cleaning are possible if the pipes are cooled at temperatures below 18°C. Viscosity increase and gel time at various temperatures, refer to Fig. 4.1/4.2 and Fig. 4.3.

 

Process	Mold Temperature	Demolding Time	Cure Conditions (Postcure)
Conventional Vacuum Casting	60 - 120°C	12 - 24 h	12h at 80°C, 4h at 90°C, 2h at 100°C, 4h at 110°C, 8h at 120°C

 

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 gelling and cure cycles in the manufacturing process could lead to a different cross linking and glass transition temperature respectively.

 

 

Fig.4.1: Viscosity increase at 70 and 80 °C (measurements with Rheomat 300 MS DIN 125 D=10s^-1)

 

Fig.4.2: Initial viscosity in function of temperature (measurements with Rheomat 300 MS DIN 125 D=10s^-1)

 

Fig.4.4: Geltime measured in function of temperature (measurement with Gelnorm Instrument)

 

Mechanical and Physical Properties

Key	Value	Unit	Test Method	Condition
Tensile strength	80 - 90	N/mm²	ISO R 527: 1993	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Elongation at break	1.0 - 1.4	%	ISO R 527: 1993	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
E modulus from tensile test	11,000 - 12,000	N/mm²	ISO R 527: 1993	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Flexural strength	140 - 150	MPa	ISO 178: 2001	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Surface strain	1.3 - 1.7	%	ISO 178: 2001	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
E modulus from flexural test	11,500 - 12,500	MPa	ISO 178: 2001	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Critical stress intensity factor (KIC)	2.90 - 3.10	MPa·m¹/²	CG 216-0/89	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Specific energy at break (GIC)	670 - 770	J/m²	CG 216-0/89	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Glass transition temperature (DSC)	80 - 90	°C	ISO 11357-2: 1999	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Coefficient of linear thermal expansion (Mean value below Tg)	31 - 35	ppm/K	ISO 11359: 1999	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Thermal conductivity	1.04 - 1.06	W/mK	Similar to ISO 8894-1	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Thermal Aging (RTI: flexural strength)	200	°C	UL file E 96722	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Water absorption (specimen: 50×50×4 mm) (10 days at 23°C)	0.10 - 0.15	% by wt	ISO 62	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Water absorption (specimen: 50×50×4 mm) (60 min at 100°C)	0.10 - 0.15	% by wt	ISO 62	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Water absorption (specimen: 50×50×4 mm) (10h at 100°C)	1.35	% by wt	ISO 62	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Water absorption (specimen: 50×50×4 mm) (100h at 100°C)	2.12	% by wt	ISO 62	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Density (Filler load: 65% by wt.)	1.87 - 1.91	g/cm³	ISO 1183	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C

 

 

Electrical Properties

Key	Value	Unit	Test Method	Condition
Breakdown strength (IEC 60243-1)	20 - 25	kV/mm	IEC 60243-1	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
HV arc resistance (IEC 61621)	185 - 190	sec	IEC 61621	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C
Tracking resistance (with test solution A)	CTI >600 - <1	N/A	IEC 60112	Cured for 4h at 80°C + 10h at 140°C, Determined on unreinforced, cast standard test specimen at 23°C

 

 

Fig.6.1: Loss factor (tan δ) and dielectric constant (εr) as a function of temperature (measurement frequency: 50 Hz) (IEC 250 / DIN 53483)

 

Fig.6.2: Volume resistivity (ρ) as a function of temperature (measurement voltage: 1000 V) (IEC 93 / DIN 53482)

Dry-type distribution transformers, glass fiber reinforced.

Aradur HY 5980 is sensitive to humidity and tends to crystallise at low storage temperature. It can be re-liquefied by stirring and heating it to 40 - 80°C.

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. For information on waste disposal and hazardous products of decomposition in the event of a fire,