Table 1 – SMR SPECIFICATION FOR GRADING PURPOSES

Parameter

SMR GRADE

SMR

10

SMR

20

SMR

10CV

SMR

20CV

SMR

CV50

SMR

CV60

SMR

L

SMR

5

SMR

GP

Colour Coding, Marker

Brown

Red

Violet

Light Yellow

Yellow

Yellow

Green

Green

Blue

Dirt (max, % wt)

0.08

0.16

0.08

0.16

0.02

0.02

0.02

0.05

0.08

Ash (max, % wt)

0.75

1.00

0.75

1.00

0.50

0.50

0.50

0.60

0.75

N2 (min, % wt)

      (max, % wt)

0.15

0.15

0.15

0.15

0.15

0.15

0.15

0.15

0.15

0.55

0.55

0.55

0.55

0.55

0.55

0.55

0.55

0.55

VM (max, % wt)

0.50

0.50

0.50

0.50

0.50

0.50

0.50

0.50

0.50

P0 (min)

30

30

NA

NA

NA

NA

35

30

NA

PRI (min)

(mean value)

≥ 50

≥ 40

≥ 50

≥ 40

≥ 60

≥ 60

≥ 60

≥ 60

≥ 50

≥ 50

≥ 40

≥ 60

≥ 50

≥ 70

≥ 70

≥ 70

≥ 70

≥ 60

WASHT (DP)

NA

NA

≤ 8 #

≤ 8 #

≤ 8

≤ 8

NA

NA

≤ 8 #

VR (ML[1’+4’]@100°C)

NA

NA

55-67

60-72

45-55

55-65

NA

NA

60-72

Lovibond Colour

individual value (max)

range (max)

 

NA

NA

 

NA

NA

  

NA

NA

  

NA

NA

  

NA

NA

  

NA

NA

  

6

2

  

NA

NA

NA

NA

Cure

NA

NA

R

R

R

R

NA

NA

R

CV = constant viscosity     GP – general purpose     L = light     R = curable (based on rheography)

# Conduct MASHT if 6 < DP ≤ 8

Regrading:     SMR 10  ↔ SMR 20 ; SMR 10CV ↔ SMR 20CV (not conform to the stated values for dirt, ash & PRI parameters).

                           SMR CV50 ↔ SMR CV60 (conform to the stated Mooney viscosity value).

MATERIAL COMPOSITION OF SMR GRADES

GRADE

MATERIAL

SMR 10, SMR20, SMR 10CV, SMR 20CV

Field grade material

SMR CV50, SMR CV60, SMR L

Whole field latex bulked and acid coagulated under controlled conditions.

SMR 5

Sheet material (RSS, ADS, Uss or mixture) subjected to further crumb processing.

SMR 5RSS

Direct baling of RSS.

SMR 5ADS

Direct baling of ADS

SMRGP

60% latex/sheet material; 40% cup lump.

Cup lump or field coagulum is rubber naturally coagulated in the tapping cup or other suitable vessel.
Field grade material consists of cup lump or field coagulum with a minor proportion of latex/sheet material.