Appearance requirements for rubber sheet

Appearance of rubber sheet:

1) The scale and height of the scars do not exceed the tolerance of the rubber plate thickness

2) Within each square meter, there shall be no more than 5 bubbles with an area less than 1cm, and the distance between any two bubbles shall not be less than 40mm.

3) Impurity scale and length shall not exceed 1/6 of the thickness of the adhesive sheet

4) Uneven edges or sea like width not exceeding 10mm, length not exceeding 1/10 of the total length of the rubber sheet

5) No cracks

2. Hardness (Shore A): 55-70

3. Tensile strength and elongation at break:

1) Tensile strength (Mpa) ≥ 5.0

2) Tensile elongation at break ≥ 250%

4. Fixed extension (150%) long-term deformation ≤ 25%

5. Hot air aging (70 ℃ * 72h): reduction rate of tensile strength ≤ 30%

6. Water absorption ≤ 1.5%

7. Electrical performance test:

1) Voltage endurance test: 25KV, hold for 1 minute, there should be no breakdown phenomenon

2) Breakdown voltage test ≥ 35KV