What are grades of Malaysian SMR?
Due to the existence of different species of rubber tree, different coagulants and different methods of rubber production, different species, colors and qualities are created. Therefore, the classification of rubber is essential. There are two types of classifications, traditional and new. In the traditional classification, the following 8 groups are:
- Ribbed smoky sheets
- White and pale yellow crepes
- Crepes with a dark brown background
Composite crepes
- Light brown crepes
- Dark brown (amber) crepes
- Poor crepes from tree bark waste
- Completely smoked brown crepes
The process of producing traditional species
Ribbed smoky sheets
These sheets are made from nursery leachate. The leachate is first passed through a sieve and poured into a diluent tank. In this tank, leachate is diluted by 15% and then coagulated, then by passing through the rollers, we increase its thickness to 2-3 mm. Due to the prominent surface of the last roller, the surface of the sheets also becomes ribbed or raised. These corrugated sheets are dried for 3-10 days under the influence of smoke. For this reason, these sheets are called ribbed smoky sheets.
Pale white and yellow crepes
Pale crepes are produced from carefully selected and maintained nursery leachate. In this method, the leachate is first filtered and then diluted and coagulated with citric acid. In this way, the coagulated yellow elements float on its surface, which separates them The leachate is passed through the strainer several times during the process to ensure it is clean. Of course, a partial coagulation method may also be used to reduce the amount of carotene in the leachate (nursery leachate is usually accompanied by a small amount of carotene, and sodium bisulfite is usually also used in the dilution tank to prevent the activity of darkening enzymes. Is added). They use a dye to neutralize the residual pigments and formic acid to coagulate the leachate itself. In this way, a hard material with a thickness of 10 mm is produced. After passing the material from different rollers, crepes with a thickness of 1-2 cm are obtained and dry after 5-7 days. The more rollers and the cleaner the water used, the clearer and brighter the crepes will be
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