A)Ribbed Smoked Sheet
Ribbed Smoked Sheet or usually called RSS is the type of rubber that consist sheets of “sheet”. It has nicely got the fumigation process and has few classes that classify its quality.
These classes are:
X RSS, this class has the highest quality of RSS.
RSS 1
RSS 2
RSS 3
RSS 4
RSS 5
B)White Crepe and Pale Crepe
This crepe is called white and pale is because it is either white coloured or light coloured. These crepes also have thick and thin types. Standard quality and classes of white crepe and pale crepe are:
No. 1 X thin white crepe
No.1 X thin pale crepe
No. 1 thin white crepe
No. 1 thick pale crepe
No.2 thick pale crepe
No. 3 thick pale crepe
C)Estate Brown Crepe
This crepe is brown coloured. It is usually used by big plantation and estate. It is made by moderate quality materials that were used to make off crepe and the leftover latex, lump of coagulum from coagulation. Some types of estate brown crepe are:
No 1 X thick brown crepe
No 2 X thick brown crepe
No 3 X thick brown crepe
D)Compo Crepe
This crepe is made out of lumps, tree scrap and leftovers from RSS or wet slab. Land and soil scrap can’t be used to make compo crepe. Some types of compo crepe are:
No 1 Compo
No 2 Compo
No 3 Compo
E)Thin Brown Crepe Re-mill
This type of crepe is the same as estate brown crepe except this is milled and become thinner. Usually thick rubber or thicker than thin brown crepe will be milled again and become thin brown crepe. Types of this crepe are:
No 1 thin brown crepe re-mills
No 2 thin brown crepe re-mills
No 3 thin brown crepe re-mills
No 4 thin brown crepe re-mills
F)Thick Blanket Crepes Ambers
This type of crepe is thick and brown in colour. It is usually made from wet slab, sheet that has not been smoked and lump with scrap from plantation or national park with good quality. Land scrap can’t be used. If you want to use scarp, bark needs to be cleaned from the remaining tree bark. Some types of these crepes are:
No 2 thick blanket crepe ambers
No 3 thick blanket crepe ambers
No 4 thick blanket crepe ambers
G)Flat Bark Crepe
This crepe is actually an earth rubber. It is made from natural rubber scrap that has not been processed, including the earth scrap that is black colour. One example of this crepe is:
Hard Flat Bark Crepe
H)Pure Smoked Blanket Crepe
This crepe is gain from milling smoked rubber especially from ribbed smoke sheet (RSS), block sheet, or pieces of ribbed smoked sheet.
I)Off Crepe
This type of crepe is not considered as standard form. It usually does not undergo direct freezing from fresh latex. This is because it is made out of low quality waste/remaining material that has, so off crepe have low value and uses. User or consumer does not really care about off crepe because it does not reach the criteria.
Concentrated Latex
Concentrated latex is a type of rubber that is in concentrated liquid state, not shaped, sheets and other solids. Concentrated latex sold in the markets will go through boiling process, and then it will be creamed through certifying process into centrifuged latex. This latex is also usually used mostly for thin rubber materials and high quality materials.
No.
Commentary
Centrifuged Latex
Creamed Latex
1
Total Solid (minimum)
61.5%
64.0%
2
Dry Rubber Content (minimum)
60.0%
62.0%
3
Difference in number of item 1 and 2 (maximum)
2.0%
2.0%
4
Ammonia Level, according the total number of water in concentrated rubber (minimum)
1.6%
1.6%
5
Viscosity at 250°C (maximum)
50 centipoises
50 centipoises
6
Sludge from fresh weigh (maximum)
0.10%
0.10%
7
Total Coagulum Level(maximum)
0.08%
0.08%
8
Number of Potassium Hydroxide/KOH
0.80
0.80
9
Mechanical Stability (minimum)
475 seconds
475 seconds
10
Copper Content Percentage from solids (maximum)
0.001%
0.001%
11
Manganese Content Percentage from solids (maximum)
0.001%
0.001%
12
Colour
Not blue,
Not grey
Not blue,
Not grey
13
Smell after being neutralize using borate
Should not stink
Should not stink
Table 1.2 - Concentrated Latex Standard Quality
Block Rubber
Block rubber is crumb rubber that has been dried and pressed, and then it will become bales with specific size. This type of rubber is light-coloured and every class has its own colour code. Standard Quality of block rubber is stated on Standard Indonesian Rubber (SIR) and Standard Malaysian Rubber (SMR) on the next page: