ARALDITE® CW 5848 / ARADUR® HW 5848

• Long pot-life, short geltime at higher temperature
• Excellent mechanical and electrical properties
• Excellent crack resistance

Latent, prefilled, hot-curing cast resin system. Convenient for processing and excellent impregnating performance.

Instrument transformers and dry type distribution transformer.

General instructions for preparing liquid resin systems: 

• Long pot life is desirable in the processing of any Araldite® casting resin system. Mix all of the components together very thoroughly at room temperature or slightly above and under vacuum. Intensive wetting of the filler is extremely important. Proper mixing will result in:

1. Better flow properties and reduced tendency to shrinkage
2. Lower internal stresses and therefore improved mechanical properties on object
3. Improved partial discharge behaviour in high voltage applications.

• For the mixing of medium- to highviscous Araldite® casting resin systems and for mixing at lower temperatures, we recommend special thin film degassing mixers that may produce additional self-heating of 10-15 K as a result of friction. For low viscous Araldite® casting resin systems, conventional anchor mixers are usually sufficient.
• The prefilled Araldite® resin and Aradur® hardener can be stored at elevated temperature (about 60°C) for up to about 1 week, de-pending on formulation. Intermittent agitation during storage is advisable to prevent filler sedimentation.
• 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.

Fig.4.1: Viscosity increase at 80°C (measurements with Brockfield)

System tested:
Araldite® CW 5869CI RESIN / Aradur® HW 5869 CI HARDENER
Mix ratio: 100 / 100 pbw
Cured for 4 hours at 80°C then 10 hours at 130°C
Determined on standard test specimen at 25°C

Fig.4.4: Geltime measured in function of temperature
(measurement with Gelnorm Instrument/ DIN 16945/6.3.1)

The effective pot-life is about 2 days at temperature 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 to prevent sedimentation and/or undesired viscosity increase. Interruptions over a weekend (approx. 48h) without cleaning are possible if the pipes are cooled at temperature below 18°C.

Viscosity increase and gel time at various temperatures, refer to Figs. 4.1 to 4.4.

Mould temperature
APG process : 140 - 160°C
Conventional vacuum casting : 70 - 100°C
Demoulding times (depending on mould temperature and casting volume)
APG process : 10 - 40 min
Conventional vacuum casting : 5 - 8h
Cure conditions
APG process (minimal postcure) : 4h at 130°C or 3h at 140°C
Conventional vacuum casting : 12h at 130°C or 8h at 140°C

To determine whether crosslinking has been carried to completion and the final proper-ties are optimal, it is necessary to carry out relevant measurements on the actual object or to measure the glass transition temperature. Different gel and postcuring cycles in the manufacturing process could influence the crosslinking and the glass transition tempera-ture respectively.

System tested:
Araldite® CW 5869 CI RESIN / Aradur® HW 5869 CI HARDENER
Mix ratio: 100 / 100 pbw

Cured for 4 hours at 80°C then 10 hours at 130°C
Determined on standard test specimen at 25°C

Fig.6.1: Loss factor (tanδ) as a function of temperature
(measurement frequency: 50 Hz)
(IEC 56250)

Fig.6.2:Volume resistivity (ρ) as a function of temperature
(measurement voltage: 1000 V)
(IEC 60093)

Mandatory and recommended industrial hygiene procedures should be followed when- ever our products are being handled and processed.

Safety precautions at workplace:
Protective clothing : yes
Gloves : essential
Arm protectors : recommended when skin contact likely
Goggles/safety glasses : yes
Respirator/dust mask recommended
Skin protection
Before starting work : Apply barrier cream to exposed skin
After washing : Apply barrier or nourishing cream
Cleansing of contaminated skin Dab off with absorbent paper, wash with warm water and alkali-free soap, then dry with disposable towels. Do not use solvents
Clean shop requirements Cover workbenches, etc. with light coloured paper. Use disposable breakers, etc.
Disposal of spillage Soak up with sawdust or cotton waste and deposit in plastic-lined bin

Ventilation:
of workshop Renew air 3 to 5 times an hour
of workplace Exhaust fans. Operatives should avoid inhaling vapours.

Contamination of the eyes by resin, hardener or casting mix should be treated immediately by flushing with clean, running water for 10 to 15 minutes. A doctor should then be consulted.
Material smeared or splashed on the skin should be dabbed off, and the contaminated area then washed and treated with a cleansing cream (see above). A doctor should be consulted in the event of severe irritation or burns. Contaminated clothing should be changed immediately. Anyone taken ill after inhaling vapours should be moved out of doors immediately. In all cases of doubt call for medical assistance.

Prefilled, liquid products always show small filler sedimentation. Before partial use we recommend to stir up carefully the components or to use each container as complete unity.

The components have to be stored under dry conditions at 18-40°C, 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.