Indian Journal of Science and Technology

Abstract

Estimating the operation lifetime of rotating parts of the medical blood bank centrifuges is very important for designers, manufactures of medical equipment and also for the operators of medical laboratories. These rotating parts such as the buckets and the liners usually experience high mechanical stresses due to heavy dynamically loads of centrifuge process. It is well known that the fatigue phenomenon is a main reason for failure of these type parts. At this study the lifetime of the Polymeric liners produced by the Iranian Sina Ebtekar company, ISECo, that utilized by the Iranian Blood Transfusion Organization, IBTO, is evaluated experimentally and by modeling with the finite element method, FEM. Randomly, a number of 36 Polypropylene liners from 2000 liners produced by the ISE Company is selected and labeled as samples. The lifetimes of the samples are recorded for a period of 12 months while they were in service simultaneously. Also by an FEM analysis, the maximum stresses occurred within the liners due to rotating loads of centrifugation is calculated. Then the lifetime of the SE Company liners is calculated based on the maximum stress of the product and the S-N fatigue life curve of Polypropylene material. A good consistency is observed between the experimental and analytical results. Based on the results of the current research, a new correlation is presented for estimating the liners. This correlation can be implemented in a maintenance program for prevent of unexpected failure of the liners that may harms the safety and health of the machine’s operators.
Keywords: Blood Bank Centrifuges, Failure Prediction, Fatigue Stress, FEM Analysis, Polypropylene Liners