Foreign Object Detection and Characterisation in Natural Rubber: A Review of Challenges, Techniques and Industrial Practices

ASM Sc. J., 21(2), 2026

Published on August 6, 2026

https://doi.org/10.32802/asmscj.2026.1011

Author: Muhammad Sazlan Abdul Kadar, Siti Zarina Mohd Muji, Nur Hafizah Ngajikin, Fauziahanim Che Seman, Yee See Khee, Ariffuddin Joret, Muhammad Hadri Hussin Chee, Nadras Othman, Mahmud Iskandar Seth A Rahim

Abstract

The characteristics of natural rubber, that is its elasticity, resilience, and cost -effectiveness, are the main reasons for its extensive usage in systems for vibration, noise, and structural shielding. Nonetheless, the existence of impurities, including m etals, polymers, minerals, and fibres, might bring the natural rubber products' reliability, safety, and performance to a halt. Such contaminants usually get into the rubber during the buying process, cutting to size, and processing. Their severity varies, making their detection quite diffic ult, as these impurities differ in size, type, and form. Various approaches are currently used to locate and identify these materials. Among the techniques applied are mechanical sieving, magnetic and eddy current separation, optical imaging, and X -ray and computed tomography scanning. Besides that, surface and chemical analysis methods like inverse gas chromatography and Fourier-transform infrared spectroscopy are also part of the process. This research explores the effect of foreign contamination on the n atural rubber's mechanical, dielectric, and environmental properties and further points out the major drawbacks of the current inspection techniques employed in the industry. The three main future research directions are: the use of artificial intelligence , non-destructive electromagnetic and microwave sensing, and the development of uniform benchmarking frameworks for real -time industrial quality monitoring.

Keywords: dielectric characterisation, foreign object contamination, isolation materials, microwave sensing, natural rubber (NR), Non-destructive testing (NDT), quality control