The Design and Building of Medium Capacity Drying House for Bokar

Abstract

Bokar, processed rubber material, is latex obtained from rubber trees of community plantation, and it can be formed into various kinds of rubber products such as: unsmoked sheet/ USS, slab and lump. Good quality of garden latex can be identified from the white bokar. It is not hard and odorless. Bokar that has been made is then ground using a rubber mill to produce milled rubber in accordance with Indonesian National Standard of Bokar no. 06-2047-2002. The purpose of this research was to design a simple rubber sheet drying house, to examine the quality of dry rubber in accordance with Indonesian National Standard, to determine the level of dry rubber produced, to find out the temperature and time constant for drying crumb rubber to get the quality of SIR 20 rubber, and to examine the odor of dry rubber. The results from this research showed that Bokars are processed using a liquid smoke coagulant with a concentration of 10-15% and it obtained a clean white rubber, odorless and slightly smelly. Bokar was ground to gain the thickness of the unsmoked sheet/ USS around 3-5 mm, then it was dried in a drying house. The components of the drying house include the drying room, heating room, heater, thermometer, blower, plenum chamber, ventilation, drying room door and electric motor. The capacity of the drying house is 200 kg of rubber sheet, with a drying temperature of 35 - 46 0C and a drying time for 6 hours. The rubber produced has good quality with average dry rubber content (DRC) was 73.75%.