Electric Insulation Epoxy Resin Casting Compound Liquid For Dry Type Transformer

JT 8869A Epoxy Resin 100 pbw

JT 8869B Epoxy Hardener 100 pbw

Liquid, Hot-curing cast resin system for outdoor electrical insulation material for medium and high voltage applications.

Dry type transformer and instrument transformer

Applications

Conventional casting with stage wise curing, or pressure gelation or Processing methods

Automatic pressure gelation casting (PG or APG process).

Properties

Long pot life

Excellent mechanical performance

Excellent crack resistance

Hubei Jiangte Insulation Composite Guangzhou Jiangte Insulation Composite Add:No.219,Zhanghua Rd(N),Economic & Development Add:Rm606,DongHong International Plaza, No.

Zone of Qianjiang City, Hubei Province, China. 113, Chebei Rd, Tianhe District, Guangzhou,China.

Tel:+86-728-6201068 Tel:+86-20-82320316

Fax:+86-728-6202066 Fax:+86-20-82315407

JT 8869A Prefilled Liquid and Solvent free Epoxy resin

JT 8869B Prefilled Liquid modified and accelerator Epoxy hardener

Remark JT 8869B contains accelerator. Prolonged storage at high ambient temperatures results in an undesirable increase in its viscosity and impairs the reactivity of the Casting Resin system.

JT 8869B is sensitive to moisture. Partly emptied containers must be resealed immediately.

Storage The components have to be stored under dry conditions at 5 - 25°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.

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.

Process data (guideline values)

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:

• better flow properties and reduced tendency to shrinkage

• lower internal stresses and therefore improved mechanical properties on object

• improved partial discharge behavior in high voltage applications.

For the mixing of medium- to high viscous Epoxy 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 Epoxy casting resin systems, conventional anchor mixers are usually sufficient. The prefilled Epoxy resin and 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.

For the viscosity and gel-time data at different temperature, refer to figure 4.1&4.4

System Preparation

Mould temperature

Automatic pressure gelatin(APG) process 140-160℃

Conventional vacuum casting 70-100℃

Demoulding time(depends on mould temperature and casting volume) 10-40min

Conventional vacuum casting 5-8h

Curing condition

APG process(shortest after-curing) 4h at 130℃ or 3h at 140℃

Conventional vacuum casting 12h at 130℃ or 8h at 140℃

It is necessary to test the spicemen to judge its performance, or to test glass transition temperature. Different gelatin and curing procedure may result in different cross-link and glass transition temperature.

Process data (guideline values)

Process viscosity

Fig4.1: viscosity increasing at 55℃( tested by Brookfiled)

Gelatin/Curing time

Fig4.4: gel-time changes as per temperature

Determined on standard specimen at 23°C

Cured for: 6h at 80°C + 4h at 100°C+6h 130°C

Electrical Properties (guideline values)

Breakdown strength IEC60243-1, 50HZ KV/mm 22-25