Latex Field coagulum

Latex continues to drip after the initial collection and coagulates naturally in the cup to form cup lump. Coagulum which forms as a film of latex on the tapped cut, called tree lace, or from latex that has dripped onto the ground, called earth scrap, is collected the next day along with the cup lump. Some smallholders may not collect the latex at all, but allow it to coagulate in the cup and collect it as cup lump. AH these methods produce mbber known as field coagulum. 

Eield latex and field coagulum are the source materials for all varieties and grades of dry natural mbber that include the conventional International grades as weH as the Technically Specified Rubbers (TSR). 

Figure 14.8 Flow diagram for processing latex and field coagulum into technically specified rubber.

Generally comprises 8% field coagulum NR, 18% smoked NR sheets, 18% NR latex, 6% plasticizer and 40% carbon black. 

Tyre rubber is developed specifically for tyre manufacturing. It is prepared by coagulating NR latex containing oil with wet crumb rubber in the following proportion 30% latex rubber, 30% unsmoked sheet, 30% field coagulum and 10% plasticizer (oil). 

Four types of coagulum are collected in the field, namely cup lump, tree lace, earth scrap and smallholders lump. Cup lump is the coagulated material found in the collection cup formed from residual latex after the latex was collected from a previous tapping. It is a cleaner material than the other three. Tree lace is the coagulum strip that the tapper peels off from the previous cut before making a new cut. It is often contaminated by manganese from the bark and... 

There are several visually graded latex NRs, including ribbed smoked sheets (RSS) and crepes such as white and pale, thin and thick hrown latex, etc. Two types of raw NR are field latex and raw coagulum, and these two types comprise all NR ( downstream )... 

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