About Technically Specified Rubber (TSR).
Natural rubber in dry marketable forms were traded in earlier
days based on visual assessment of quality only. This was
a limitation for RSS and Crepe rubber with the end users.
Hence efforts were made to grade natural rubber based on
certain technical properties which could provide guarantees
to the consumers of a certain minimum quality. The International
Standards Organization (ISO) developed the first draft standards
in 1964 in its meeting held in India for the grading and
marketing of Block Rubber or Technically Specified Rubber
(TSR).
The
TSRs are mostly the block type made, adopting new methods
of processing. . All the block rubbers are guaranteed to
conform to certain technical specifications as laid out
by the national schemes or by the ISO 2000 standards.
TSR
is known in different rubber producing countries in different
names as shown below-.
| Country
|
Country
scheme Code |
| Malaysia |
SMR
|
Standard
Malaysian Rubber |
| Indonesia
|
SIR |
Standard
Indonesian Rubber |
| Thailand |
STR |
Standard
Tai Rubber |
| Singapore
|
SSR |
Singapore
specified Rubber |
| Vietnam |
CSV |
Coautchouc
standard Vietnam |
| INDIA |
ISNR |
Indian
Standard Natural Rubber |
Following
are the different grades of TSR.
| Country
|
Country
scheme Code |
| 1)
TSR 3 CV |
Indian
name |
ISNR
3 CV |
|
2) TSR 3 L |
Indian
name |
ISNR
3 L |
| 3)
TSR 5 |
Indian
name |
ISNR
5 |
| 4)
TSR 10 |
Indian
name |
ISNR
10 |
| 1)
TSR 20 |
Indian
name |
ISNR
20 |
| 1)
TSR 50 |
Indian
name |
ISNR
50 |
| |
|
|
1.
TSR - CV. This is a viscosity stabilized high quality
grade, which provides a unique cost advantage in eliminating
the pre mastication process and high reject rates.
2.
TSR - L . It is a light colour rubber produced from
high quality latex, having low ash and dirt content.
3.
TSR 5. This grade of rubber is produced from fresh coagulum
and or from un smoked sheets and air dried sheets. It process
better specially in extrusion, calendaring and joining of
cycle inner tubes .
4.
TSR 10. This grade of rubber is produced from clean
and fresh field coagulum or from un smoked sheets. It has
good technological properties similar to those of RSS 2
and RSS 3 and has the advantage of lower viscosity and easier
mixing characteristics.
5. TSR 20. It is a large volume grade of TSR, produced
mostly from field coagulum and or a blend of field coagulum
with lower grades of RSS and un smoked sheets. It has good
processing characteristics and physical properties coupled
with low viscosity and easier mixing characteristics.
6.
TSR 50. It is the lowest grade of TSR and is produced
from old dry field coagulum or partly de graded rubber.
The rubber usually will have low viscosity, but have only
lower technological properties.
The
bale of TSR shall be free from skim rubber. The material
shall be free from evident mould growth.
The TSR shall comply with the following requirement given
in the table for ISO 2000 .
|
T
S R Specifications for ISO 2000
|
|
Parameters
|
TSR-CV
|
TSR
- L
|
TSR
- 5
|
TSR
-10
|
TSR
-20
|
TSR
-50
|
|
Dirt
retained on 44 sieve (max % wt)
|
0.05
|
0.5
|
0.5
|
0.10
|
0.20
|
0.50
|
|
Ash
content (max % wt)
|
0.60
|
0.60
|
0.60
|
0.75
|
1.00
|
1.50
|
|
Nitrogen
content (max % wt)
|
0.60
|
0.60
|
0.60
|
0.60
|
0.60
|
0.60
|
|
Volatile
Matter (max % wt)
|
0.80
|
0.80
|
0.80
|
0.80
|
0.80
|
0.80
|
|
Initial
Wallace plasticity P0 (min)
|
…
|
30
|
30
|
30
|
30
|
30
|
|
Plastic
Retention Index (Min)
|
60
|
60
|
60
|
50
|
40
|
30
|
|
Colour
(Max) Lovibond Units
|
…
|
6
|
…
|
…
|
…
|
…
|
Packing.
The
blocks are generally 33.33 bales in the international market
and 25 kg blocks in India.
The bales will be wrapped in polythene sheets which are
easily dispersible in rubber.
Marking.
Each
bale of TSR shall be marked indelibly with grade of rubber,
net mass of bale, name of the producer and month and year
of production
