Wednesday, 15 May 2013

Natural Rubber Latex Processing

  A rubber grower from south district shares his  practical experience for rubber latex processing

Objective: Production of rubber sheet

1. Equipments required for rubber latex processing
   a. Alluminium dish / tray
   b. Bucket
   c. Measuring Cylinder
   d. Roller machine
   e. Seiving machine

2. Chemicals required for latex processing
   a. Formic acid
   b. Golden touch (Antifungal)
3. Process of mixing of water with latex
   a. Water quantity varies according to DRC content of latex
   b. Increased DRC means, more water requirement decrease or less DRC means, less water
   c. As a general rule, equal quantity of water is maxed with latex

4. Process of mixing of acid with latex
   a. 1st Acid is diluted by mixing of 5gm formic acid with 5 liter of water
   b. 200ml diluted acid is mixed in each tray containing latex
   c. In each tray 1.5 to 2 liters of latex is poured
   d. The mixed latex is kept for 20-24 hours for coagulation
   e. Quantity of latex per tray is maintained within the range of 1.5 to 2 liter for maintaining prescribed weight of dry rubber sheet (500 gm).

5. Making of rubber sheet
   a. After 20-24 hours, coagulum processed through 2(two) steps
   i. First coagulum is passed through plane roller machine for 3times which produces plain & smooth surfaced rubber sheet.
   ii. In second step, the smooth & plain rubber sheet is passed through grooved roller machine

6. Drying of rubber sheet
   a. There are two process of drying as follows:
   i. Sun dry
   ii. Smoke dry
   iii. Sun drying exclusively followed where there's no smoke house. In this case, 5-6 days sun drying is required depending upon the seasonal condition.
   iv. In case of smoke house drying, rolled sheet is kept for 24 hours in the shade later on, it is transferred to the smoke house for drying up to 3-4 days.

7. Few words on DRC of natural rubber latex in Tripura
   a. DRC content of latex during the month from June to August = 30-35 DRC
   b. DRC content of latex during the month from september to december = 25 to 30 DRC
   c. DRC content of latex during the month of January to May
          January = 20-25 DRC
         April to May = 35-38 DRC

N.B.: Field level practical knowledge may not reflect actual methods of latex processing.