JB/T 10442.2-2017 English PDF (JBT10442.2-2017)

This part of JB/T 10442 specifies the test method of the insulating paper coated with resin binder forming rhombic pattern for electrical purposes. This part applies to insulating paper coated with resin binder forming rhombic pattern for electrical purposes.

JB/T 10442.2-2017
JB
MECHANICAL INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 29.035.99
K 15
Filing No.: 58356-2017
Replacing JB/T 10442.2-2004
Insulating paper coated with resin binder forming
rhombic pattern for electrical purposes - Part 2:
Methods of test
ISSUED ON: APRIL 12, 2017
IMPLEMENTED ON: JANUARY 01, 2018
Issued by: Ministry of Industry and Information Technology of PRC
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 General requirements for tests ... 4
4 Appearance ... 5
5 Thickness ... 5
6 Tightness of substrate ... 6
7 Moisture ... 7
8 Ash content ... 8
9 Conductivity of water extract ... 9
10 pH value of water extract ... 9
11 Oil absorption ... 9
12 Tensile strength and elongation at break... 10
13 Tear strength ... 12
14 Bond strength ... 12
15 Breakdown voltage ... 13
16 Contamination of transformer oil ... 14
Insulating paper coated with resin binder forming
rhombic pattern for electrical purposes - Part 2:
Methods of test
1 Scope
This part of JB/T 10442 specifies the test method of the insulating paper coated with resin binder forming rhombic pattern for electrical purposes.
This part applies to insulating paper coated with resin binder forming rhombic pattern for electrical purposes.
2 Normative references
The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this standard.
GB/T 451.3 Paper and board - Determination of thickness
GB/T 455 Paper and board - Determination of tearing resistance
GB/T 1408.1 Electrical strength of insulating materials - Test methods - Part 1: Tests at power frequencies
GB/T 1545 Paper board and pulp - Determination of acidity or alkalinity GB 2536 Fluids for electrotechnical applications - Unused mineral insulating oils for transformers and switchgear
GB/T 5654 Insulating liquids - Measurement of relative permittivity dielectric dissipation factor (tanδ) and d.c. resistivity
GB/T 7196 Methods of test for the determination of ionic impurities in
electrical insulating materials by extraction with liquids
3 General requirements for tests
Unless otherwise specified, the samples shall be conditioned at 23°C ± 2°C and 5.4.1 Adhesive thickness of single-sided coating products
The median value of the thickness, which is measured in 5.2, minus the median value of the thickness, which is measured in 5.3, to get the adhesive thickness of the single-sided coating product, in micrometers (µm).
5.4.2 Adhesive thickness of double-sided coating products
The median value of the thickness, which is measured in 5.2, minus the median value of the thickness, which is measured in 5.3; THEN, it is divided by 2, to get the adhesive thickness of the double-sided coating product, in micrometers (µm).
6 Tightness of substrate
6.1 Instruments and tools
The instruments and tools used in the test are as follows:
- Analytical balance: Sensitivity is 0.001 g;
- Constant pressure thickness gauge: Same as the requirements in 5.1;
- Steel ruler: The graduation value is 0.5 mm;
- Sampling plate: 100 mm x 100 mm.
6.2 Specimen
Cut three specimens of 100 mm x 100 mm, by the sampling plate, at even
interval at least 20 mm from the edge of the paper roll width.
6.3 Test procedure
6.3.1 Weigh the mass m1 of each specimen, accurate to 0.001 g. Measure the length, width, thickness of the specimen, in millimeters (mm).
6.3.2 The tightness is calculated according to formula (1).
Where:
ρ - The tightness of the specimen, in grams per cubic centimeter (g/cm3); m1 - The mass of the specimen, in grams (g);
in grams (g);
m4 - The mass of the specimen container plus the specimen, after baking, in grams (g);
m2 - The mass of the specimen container, in grams (g).
7.4 Results
Take the median of the three tests as the result. Report the maximum and minimum values, accurate to 0.1%.
8 Ash content
8.1 Instruments and equipment
The instruments and equipment used in the test are as follows:
- Balance: Sensitivity is 0.0001 g;
- High temperature furnace: The temperature control accuracy is ±25°C;
- Crucible.
8.2 Specimen
According to the provisions of 7.2, cut 3 specimens, each of which is about 2 g ~ 5 g. Remove the moisture according to the baking conditions for measuring the moisture. It may also use 2 g of dry specimen, that has not been exposed to moisture after measuring the moisture.
8.3 Test procedure
Burn the crucible at 925°C ± 25°C in advance. Take it out and put it in a desiccator. After cooling to room temperature, weigh it (m5). Then add the dried specimen. Weigh it (m6). Burn it to carbonize. Then move it into a high- temperature furnace. Burn it at 925°C ± 25°C for 2 hours. Take out the crucible. Cool it in a desiccator. Weigh it (m7). If necessary, the burning can be repeated, until the weight is constant. All measurements shall be accurate to 0.0001 g. The ash content is calculated according to formula (3).
Where:
Ac - Ash content of the specimen, %;
follows:
- Analytical balance: The sensitivity is 0.001 g;
- Oven: The temperature control accuracy is ±2°C;
- Sample container: Stainless steel tank;
- Transformer oil: According to the requirements of GB 2536.
11.2 Specimen
Take three 75 mm x 75 mm specimens, which are at even interval at least 20 mm from the edge of the paper roll width.
11.3 Test procedure
Put the specimen in the oven. Heat up to 105°C ± 2°C. Keep it for 2 h. Take it out and put it in a desiccator, to cool to room temperature. Weigh it (m8). Then dry it in an oven at 105°C ± 2°C for 20 minutes. Take it out and immediately immerse it in transformer oil, which was preheated to 90°C ± 2°C. Then cool to room temperature. Take out the specimen. Use filter paper to quickly absorb the excess oil from the surface. Weigh it (m9). The oil absorption is calculated according to formula (4).
Where:
Oa - Oil absorption of specimen, %;
m9 - The mass of the specimen after oil absorption, in grams (g);
m8 - The mass of the specimen before oil absorption, in grams (g).
11.4 Results
Take the median of the three tests as the result of oil absorption. Report the maximum and minimum values.
12 Tensile strength and elongation at break
12.1 Equipment
The equipment used in the test is as follows:
Constant-speed mobile testing machine: The speed can be adjusted, to make E - The elongation at break of the specimen, %;
ΔL - The increase in length of the specimen when it breaks, in millimeters (mm);
L - The initial length of the specimen between the clamps, in millimeters (mm). 12.4 Results
Take the median of nine test data, in each direction, as the result of tensile strength or elongation at break. Report the maximum and minimum values. 13 Tear strength
Carry out the test in accordance with the provisions of GB/T 455. Make nine tests in each of the longitudinal and transverse directions. Use the median of the test values, in each direction, as the result of the tear strength. Report the maximum and minimum values.
14 Bond strength
14.1 Equipment and instruments
The equipment and instruments used in the test are as follows:
- Oven: The temperature control accuracy is ± 2°C;
- Constant-speed mobile material testing machine: The speed can be
adjusted to 5 mm/min. The graduation value is 10% of the value required by the individual material specifications. The testing machine is equipped with a test heating box, which has a temperature control accuracy of ±2°C. 14.2 Preparation of specimens
Take two flat, smooth, clean aluminum or copper plates, which have a thickness of 0.5 ~ 1.0 mm, a width of 50 mm, a length of about 150 mm; overlap with each other for 50 mm along the direction parallel to the long axis. Clamp 4 layers of specimen, which has a size of 50 mm x 50 mm. Apply a pressure of 15 kPa on the surface of the overlap joint. Cure it according to the curing conditions specified in Chapter 3 (Be careful to prevent the poor contact, BETWEEN the metal plate AND the specimen, or BETWEEN the specimen AND specimen,
due to the upwarp of the metal plate, during the operation).
Prepare 5 specimens.
14.3 Test procedure