GB/T 1981.4-2009Varnishes used for electrical insulation - Part 4: Polyester-imide varnishes (English PDF)

1 Scope

GB/T 1981 This section specifies the type of polyester-imide varnish, requirements, test methods, inspection rules, packaging, labeling, storage

And transportation.

This section applies to electrical insulation class H polyester-imide varnish.

2 Normative references

The following documents contain provisions which, through reference to GB/T 1981 to the present, constitute provisions of this section. For dated reference documents

Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section

Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

GB/T 1981.1-2007 electrical insulating paints - Part 1. Definitions and general requirements (IEC 60464-1.1998, IDT)

GB/T 1981.2-2009 electrical insulating paints - Part 2. Test methods (IEC 60464-2.2001, MOD)

GB/T 6109.5-2008 enamelled round winding wire - Part 5. 180 polyester enamelled round copper wire (IEC 60317-8.1997,

IDT)

3 Models

H-level model for the polyester-imide varnish. 1056.

4 Requirements

All materials one delivery, in addition shall comply with the requirements of GB/T 1981.1-2007 prescribed, it should also comply with this section in Table 1

Requirements.

Table 1 polyester-imide varnish performance requirements

No. Property Unit Requirements

1 Appearance -

Liquid paint should be transparent, no mechanical impurities and undissolved

Particle; the film should be smooth and shiny.

2 Viscosity (No

4 cup, 23 °C ± 1 °C) s 70 ± 7

3 Non-volatile content (130 °C ± 2 °C/2h)% 50 ± 2

Thick layer is cured (120 °C ± 2 °C/4h + 150 °C ±

2 °C/8h)

- No smaller than S1-U1-I4.2 uniform

5 Effect of enameled wire paint - pencil hardness of not less than 2H

Volume resistivity

Normal (23 °C ± 2 °C)

Immersion (room temperature, 168h) after

ohm · m >=1.0 × 1012

>=1.0 × 1010

7 dielectric loss factor (180 °C ± 2 °C) - supply and demand sides agreed […]