Tribological Consideration In Roller Mill Machines For Agriculture Applications

Roller mill is an important part of machines for preparation of agricultural food stuffs. Tribological loading is the main type of load that should be considered when investigating the design failure of roller mills or of the low quality of grinding products. In the current work a comprehensive analysis of the roller design to withstand tribological was undertaken. Three-body abrasive loading (3BA) was found to be the key element to be considered in designing the roller. High stress three-body abrasion experiments were conducted on polyester and epoxy polymers to measure the wear and frictional characteristics of the selected material, different loads, durations and sand grain sizes were tested. Scanning electron microscopy and optical microscopy were used to categorize the damage on the worn surface of the materials and the causes of failure. The current results are compared with the performance of mild steel results based on the literature. The results revealed that polyester had relatively poor wear performance compared to epoxy and steel especially when large sand grains were used. The wear mechanisms on the polyester surface were macro-pitting, fracture, ploughing and defragmentation; while epoxy showed micro-pitting and defragmentation. Epoxy material performance indicates that it has potential for replacing metal rollers in the milling machine.