Item

Unit

Super grade

First grade

Qualified grade

Volatilization

%

≤0.75

≤1.00

≤1.30

Total ash

%

≤0.75

≤1.00

≤1.50

Organic acid

%

4.50-6.75

4.50-7.00

4.50-7.00

Soap

%

≤0.50

≤0.50

≤0.50

Combine styrene

%

22.50-24.50

22.50-24.50

22.50-24.50

Crude rubber Mooney viscosity 100C MLI+4

%

45-55

45-56

45-57

Mix rubber Mooney viscosity 100C MLI+4

%

≤90

≤90

≤90

25 min

Mpa

11.30-15.80

10.8-16.30

13.0-19.50

300%Stress at definite elongation 145°C×35min

Mpa

14.1-18.6

13.6-19.1

13.0-19.50

300%Stress at definite elongation 145°C×50min

Mpa

14.9-19.4

14.4-19.9

13.0-19.50

Tensile strength 145°C×50min

%

≥23.7

≥22.50

≥22.50

Elongation at failure 145°C×50min

%

≥415

≥400

≥400