Raw rubber properties and mechanical properties of smoked sheet rubber made from natural rubber latex preserved using ammonia

Abstract

Abstract:A study was carried out to understand the processing behaviour of smoked sheet rubber manufactured using natural rubber field latex (NRFL) preserved using ammonia at different concentrations. The NRFL preserved with sodium sulphite was used as a control together with unpreserved NRFL. The NRFL preserved using different ammonia concentrations were kept for different time intervals before further processing. Sheet rubber was manufactured using the preserved latex according to the standard manufacturing procedures. Preservation ability, acid requirement for coagulation, drying characteristics, and the raw rubber properties and mechanical properties of sheet rubber were evaluated. The results revealed that the ammonia concentration should exceed 0.15% to keep the latex for more than a day without pre-coagulation. As the ammonia concentration is higher, the acid requirement was higher. Sheet rubber manufactured using ammoniated latex takes marginally longer time to reach complete dryness. The ammonia concentration and time of preservation has a significant effect on raw rubber properties other than un-aged rapid plasticity number. There was no significant effect (p>0.05) on the mechanical properties other than aged-tensile, tear properties and rebound resilience at aged state.

Line Balancing Analysis in Ribbed Smoked Sheet Production Using Heuristics Methods (Study at PT. Wabin Jayatama, Serang, Banten, Indonesia)

“…The first step that needs to be done before doing the calculation is to set the precedence constraints. Precedence constraints are predecessor constraints in completing a work element, there are sequences of tasks that must be fulfilled beforehand so that the element be executed [13]. Activities start from element O-6 because activities O-1 to O-5 have started the previous day (work in process).…”