3240 Epoxy Phenolic Resin Glass Cloth Rigid

Laminated Sheet

Standard No.: Q/DJ10-143-2000

    3240 is made from alkali-free glass fabric impregnated with epoxy phenolic resin . It is made at high temperature and high pressure. It has high mechanical strength and excellent electric properties, suitable for making insulating structural parts and components in electric motor and electric apparatus. It can also be used in condition of humidity and in transformer oil.

1   Technical requirements

1.1  Appearance

Its surface should be flat and smooth, free of bubbles, wrinkles and crackles and other defects. If dent and uneven color exist, little stain is allowed. Edges should show net cut and be free of delamination and crackles.

1.2   Dimensions and tolerance 

1.2.1 Length and width are as shown in Form 1.

    Form 1                           mm

Length and Width

Tolerance

450～970

±15

＞970～1970

±25

1.2.2   Nominal thickness and tolerance are are shown in Form 2

Form 2                           mm

Nominal Thickness

Tolerance

Nominal Thickness

Tolerance

0.5

0.6

0.8

1.0

1.2

1.6

2.0

2.5

3.0

4.0

5.0

6.0

8.0

±0.12

±0.13

±0.16

±0.18

±0.20

±0.24

±0.28

±0.33

±0.37

±0.45

±0.52

±0.60

±0.72

10

12

14

16

20

25

30

35

40

45

50

60

80

±0.82

±0.94

±1.02

±1.12

±1.30

±1.50

±1.70

±1.95

±2.10

±2.30

±2.45

±2.50

±2.80

Note: The product of non-nominal thickness is settled upon negotiation between sellers and buyers, its deviation adopts the value of next bigger nominal thickness. 

1.3   Bending deflection: shown in Form 3

  Form 3                    mm

 Thickness

Bending deflection

1000 (Ruler length)

1000 (Ruler length)

3.0～6.0

＞6.0～8.0

＞8.0

≤10

≤8

≤6

≤2.5

≤2.0

≤1.5

1.4  Machining

The laminated sheets should be free from crackles and scraps after being machined such as sawing, drilling, lathing and milling.

1.5  The mechanical, physical and dielectric properties of the laminated sheets are as shown in Form 4.

     Form 4

No.

Properties

Units

Values

1

    Density

g/cm3

1.7～1.9

2

Martens temperature         MD

℃

≥200

3

Thermal stability

℃

200

4

Oil resistance

in transformer oil    4h

℃

130

5

Water absorption

%

≤0.8

6

Bending strength

perpendicular to the laminations

MD

MPa

≥350

TD

≥290

7

Tensile strength

MD

MPa

≥300

TD

≥220

8

Charpy impact strength

No gap

3mm~9.5mm

MD

kJ/m2

≥60

TD

≥50

>9.5mm

MD

≥220

TD

≥200

9

Bond strength

N

≥5600

10

Surface resistivity

At room temp.

Ω

≥1.0×1013

After 24h submerged in water

≥1.0×1011

11

Volume resistivity

At room temp.

Ω•m

≥1.0×1011

After 24h submerged in water

≥1.0×109

12

Insulation resistance

 parallel to the laminations

At room temp.

Ω

≥1.0×1010

After 24h submerged in water

≥1.0×108

13

Dielectric strength

 perpendicular to the laminations in transformer oil at 90℃±2℃

0.5 mm～1mm

MV/m

≥22

1.1 mm～3mm

≥20

14

Dissipation factor    50Hz

—

≤0.030

15

Breakdown voltage

parallel to the laminations in transformer oil at 90℃±2℃

kV

≥30

2    Testing methods

2.1  ：Appearance

Visual observation

2.2   Machining

As per Machining Methods for Insulating Laminated Products, Standard No.JB/Z141-79.

2.3   Specimen treatment before test

As per Chapter 2 of GB5130-1985. The specimen should be treated in an oven at 105℃ circular sirocco for one hour.

2.4   Density

As per Method A of GB1033-1985. Weight of specimen: 28-50g

2.5   Martens temperature

As per GB1035. Test is unnecessary for the nominal thickness less than 10mm.

2.6   Thermal stability and oil resistance

2.6.1  Specimen: Three specimens for each group; Dimension: 100mm × 100mm;

Thickness: Nominal

2.6.2  Heat resistance: Hang the specimens in the oven with thin metal thread, avoid touch between specimen and specimen or between specimens and wall of the oven. Increase the temperature to 200℃ within 30min-60min and then keep stable for 24 hours. After that, decrease the temperature to room temperature. Take out the specimens,then observe its appearance. Delamination and crack are not allowed, small cracks (like hair diameter) are allowed. 

2.6.3  Oil resistance: Put specimens into 70℃±2℃ container filled with transformer oil,  avoid touches between specimen and specimen and between specimens and container. Increase the temperature to 130℃±2℃ within 40min～90min and keep stable for four hours. Take out the specimens and check immediately. Bubbles and tympanites are not allowed, small cracks on the edges are allowed.

2.7   Charpy impact strength

No less than 5 specimens for each group, if the nominal thickness of the specimen is more than 10mm, they should be processed to 10mm±0.2mm on one side. Measure 3 places to get their arithmetic average value as its testing result, the precision for testing the dimension should be 0.1mm. The span should be adjusted according to the thickness of the specimen. If the nominal thickness is no more than 5mm,the span should be 40mm±0.2mm; if the nominal thickness is more than 5mm, the span should be 70mm±2mm. The test should be parallel to the lamination, the specimen processed from one side should face to bob.  Impact speed of bob is 3.5m/s±0.5m/s. If the specimen does not break or does not break in the middle part of trisection, the testing result is invalid. Rare values of testing results can have the deviation of less than ±15% compared with the average value.

                                    An

               Impact strength（σn）＝──────

                                     bn·hn

     σn── Impact strength kJ/m；

     A n ── kJ

     bn ──Width of specimen; m

     hn ── Thickness of specimen; m

2.8  Surface resistivity & Volume resistivity

The distance between the testing electrode and the protecting electrode is 2mm. The diameter of the testing electrode is 50mm±0.1mm. The inner diameter of protecting electrode is 54mm±0.1.mm and its outer diameter is 74mm±0.1mm.

2.9  Breakdown voltage parallel to the laminations

The dimension of the specimen: 60mm×30mm.

Drill hole in the middle of the thickness of the specimen, the depth of the hole is 20mm, and the testing distance is 10mm±0.2mm. Use the high speed step-up method to test. Use the average value of the breakdown voltage of 5 specimens as the testing result. If rare values have the deviation of 15% compared with the average value, another 5 specimens should be tested, and use the average value of the breakdown voltage of 10 specimens as the testing result.

The others are as per GB5130-1985.

3  Inspection, marks, package, transportation and storage

3.1  The inspection items are as per Clause 1.1,1.2,1.3 and Item 13 of Form 3 in Clause 1.5, the items in Clause 1.1,1.2,1.3 should be checked one by one.

Under the conditions stipulated , the storage life is 18 months after leaving factory. If the storage life is over 18 months, the product can still be used only when being tested to be qualified.

The other items are as per GB1305-1985.

4  Remarks

The laminated sheets have different properties compared with the metal. The methods of JB/Z141-79 must be adopted to avoid damage when the product is machined.

Thermal conductivity of the laminated sheets is small, so high cutting speed and small depth of cut should be adopted when the product is machined.