OPTIMIZING CUP LUMP RUBBER QUALITY WITH LATEX STIRRING SPOON AND 7% FORMIC ACID

Abstract

          The objectives of this research were to examine the percentage of dry rubber content of cup lump rubber, and to analyze the properties of cup lump rubber obtained by using a latex stirring spoon and 7% formic acid. For studying the percentage of dry rubber content, the sample group was 30 rubber farmers, obtained by employing purposive sampling method. Then, rubber samples were made by randomly collecting 3 replicates of convenience samples of 10 kilograms each from each rubber farmer sample group, totaling 30 kilograms per each. The rubber samples were rolled with a crepe machine, then desiccated and dried in the oven. Finally, the dried crapes were weighed and the percentage of dry rubber content calculated. For the analysis of cup lump rubber properties, sample groups were rubber farmers from six institutes who had been trained in making rubber cup lumps by using a latex stirring spoon and 7% formic acid. After that, 3 kilograms of cub lump rubber were randomly collected from each farmer. These rubber samples were mixed and sampled at a rate of 10 kilograms per institution. Then, 7 features were then analyzed in the laboratories, including Dirt Content, Volatile Matter Content, Ash Content, Nitrogen Content, Initial Wallace Plasticity, Plasticity Retention Index, and Mooney Viscosity ML. Finally, the test results were compared with the property standards of STR 10 and STR 20 block rubber. The results revealed that the average percentage of dry rubber content of cup lump rubber was 8.39% (S.D. = 0.25), with the lowest individual average of 8.03% and the highest individual average of 8.87%. Concerning the property analysis of the rubber cup lumps, it was found that the test results of all 6 institutes passed all STR 20 block rubber standard criteria. However, there were two properties that must be improved in order to meet the STR 10 rubber blocks standard, namely Dirt Content value and Plasticity Retention Index. These results reflected that if farmers implemented a technique of using a latex spoon along with using 7% formic acid regularly and continuously, which is one of the important guidelines of good and appropriate agricultural practices (Good Agricultural Practices: GAP), it would improve the quality of rubber cup lump. Moreover, prices and sustainability of occupation would be significantly affected.