The quality of rubber processed materials, that is produced by the farmer is generally low and can be seen from their colour,  pollutants levels, foul odour and the very cheap price. To improve the quality of the rubber should be done both in terms of its treatment and processing equipment. The main objective of this research is to enhance and improve the quality of farmer's rubber processed materials by using natural coagulant which liquid smoke to agglomerate the rubber, and designing of rubber grinding machine. The component of rubber grinding machine including hopper, regulating entry materials, three rollers, pulleys and belt, outlet, gears, engine, regulating the thickness and chassis. In this research, the thickness rubber after grinding is 3-5 mm accordance with Indonesian National Standard rubber. Processed material rubber produced is white and no pollutants. The coagulant used was liquid smoke with a concentration of 10 -20%, where this addition affects the agglomeration speed of rubber and smelled slightly of smoke. The average rate of Feed is 48.58 kg / h, a capacity of the machine is 37.40 kg/hr and cost of operation is Rp. 650 / kg.

Kandis acid is one of the spices that is often used for cooking and health ingredient. Processing kandis acid fruit skin is by the drying process. Drying can be done using tools or in the sun. Drying using tools is still not optimal because there is no temperature control during drying, this study drying was carried out using an arduino-based oven so that the initial temperature could be determined and the temperature during drying could be controlled. This study aims to evaluate the drying temperature control in an arduino uno-based oven and also to evaluate the drying method used on the quality of the kandis acid produced. Based on the research that has been done, controlling the drying temperature using an arduino uno-based oven that has been running well, the oven automatically controls the drying temperature to return to the set point temperature used (60 0C). The best quality of kandis acid is drying using a tool, seen from observations such as mold growth, drying time and drying rate. However, in drying using the sun, the value of vitamin C has a higher value than drying using a tool. The rind of the kandis acid used was 2,7 kg in each drying, the initial moisture content in drying using a tool was 83,289% with a final moisture content of 9,672% and the initial moisture content drying using sunlight was 83,744% with a final moisture content of 10,796%. The drying time for drying using a tool is 9,3 hours with a drying rate of 0,041 kg/hour, while for drying using sunlight was 20,7 hours with a drying rate of 0,036 kg/hour.

Bokar, processed rubber material, is latex obtained from rubber trees of community plantations. The quality of latex can be identified from its features which are white, relatively soft, and odorless. The purpose of this research was to design a simple rubber sheet drying house and examine the quality of dry rubber under Indonesian National Standard. Bokars are processed using a liquid smoke coagulant with a concentration of 10-15% and it obtained a clean white rubber although it has a slight smoke smell. Before drying, Bokar had ground to gain the thickness of the unsmoked sheet/ USS around 3-5 mm. 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 – 46oC and 6 hours drying time. The rubber produced has good quality with average dry rubber content (DRC) was 73.75%.