Industrial-Scale Comparison of Conventional and Modern Processing Routes for Natural Rubber: Energy Efficiency and Process–Property Relationships

Abstract

Natural rubber (NR) block production from cup lump conventionally requires multiple mechanical processing stages, resulting in high energy consumption and complex manufacturing operations. This study presents a modern process approach by using a Rotary Disc Granulator (RDG) to integrate size reduction and cleaning into a simplified two-step processing. The modern process was evaluated in terms of energy consumption, productivity, drying performance, molecular characteristics, rheological behavior, and final product properties, with comparison to the conventional process. The modern process reduced Specific Energy Consumption (SEC) from 89.64±9.52 to 62.56±4.40 kWh/ton, corresponding to an energy saving of approximately 30%, while maintaining comparable productivity and meeting Standard Thai Rubber (STR 20) quality requirements. Improved drying efficiency was achieved through enhanced heat transfer associated with the more uniform pellet morphology produced by the RDG. Molecular and rheological analyses further demonstrated higher molecular weight, lower long-chain branching, and improved thermal stability, indicating reduced mechanical degradation during processing. Despite the simplified process, the cured rubber exhibited comparable curing characteristics and mechanical properties to those produced by the conventional process. These findings demonstrate that process intensification using an RDG provides a practical and sustainable strategy for improving the energy efficiency of industrial natural rubber manufacturing while preserving product quality.