-------------------------------------------------+----------------------- CHAMBER 1.--TEMPERATURE 160°-180°F. | -------------------------------------------------|CHAMBER 2.--TEMPERATURE _NO. OF | _DRYING | _WEIGHT OF | _WEIGHT OF | 150°-165°F. Tray._ | Period._ | Wet Rubber._ | Dry Rubber._ | --------+----------+--------------+--------------+----------------------- |Hrs. Mins.| Lbs. | Lbs. | 1 | 1 22 | 7-1/2 | 6 |Worked similarly 2 | 1 42 | 7-1/2 | 6 |to No. 1. Yielded 3 | 1 57 | 7-1/2 | 6 |in 2 hrs. 23 mins. 4 | 1 57 | 7-1/2 | 6 |70-3/4 lbs. dry rubber, 5 | 1 57 | 7 | 5-3/4 |from 87-1/2 lbs. wet 6 | 1 57 | 7-1/2 | 6 |rubber. 7 | 2 0 | 7-1/2 | 6 | 8 | 2 0 | 7-1/2 | 6 | 9 | 2 11 | 6-1/2 | 5 | 10 | 2 11 | 7-1/2 | 6 | 11 | 2 11 | 7-1/2 | 6 | 12 | 2 18 | 7-1/2 | 6 | --------+----------+--------------+--------------+----------------------- | | 88-1/2 | 70-3/4 | --------+----------+--------------+--------------+----------------------- It will be seen, therefore, that the drier had an output in 2 hrs. 23 mins. of 141-1/2 lbs., which is at the rate of 1 lb. per minute approximately. As the rubber leaves the driers it resembles vacuum-dried rubber in being surface-sticky. This stickiness is only temporary, and is got rid of by passing the crepe through wet rolls. Opinions differ as to when this rolling should be given. On some estates the rubber is only allowed to cool a little before passing through the rolls; on others it is given a day or so before rolling. The methods of rolling also differ. In some factories the rubber has been cut to lengths before drying, and these lengths are merely rolled together by simple pressure. Other estates prefer to re-macerate the crepe while still fairly warm and soft. It is probable that little harm, if any, results from this re-maceration while the rubber is soft, as it is more easily worked in this condition. The thick rubber is then generally hung for a few days to air-dry before packing. As most of the moisture taken up by the dry rubber is surface moisture, three or four days is usually found ample for air-drying.