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Abstract
Fatigue Resistance of Medical Gloves
Test equipment and a method for studying the fatigue
resistance of medical gloves were developed. The method involves a continuous
inflation and deflation of glove under a set of controlled conditions until
the glove loses its integrity by the formation of a hole or a tear. Under
the controlled conditions the deformation characteristic at certain critical
parts of the glove during use was simulated. It was observed that the loss
of glove integrity during the fatigue test occurred mostly at areas near
the base and crotches of fingers. The type of fatigue failure displayed
by natural rubber (NR) gloves, are holes and tears. The fatigue , failure
of nitrile and vinyl gloves was mainly by formation of tear. Fatigue lives
of NR examination and surgical gloves at 50% strain measured at the base
of the second finger, at an inflation-deflation frequency of 0.5 cycle per
second were found to exceed 1000 cycles. Under similar conditions, the fatigue
lives of nitrile and vinyl examination gloves were found to be less than
400 cycles. There was generally no clear relationship between the physical
properties and the fatigue resistance of NR and nitrile gloves. For vinyl
gloves, the fatigue resistance increased with decreasing stiffness of the
glove. Depending upon the type of glove, the fatigue life of glove might
increase or decrease after ageing. Rather unexpectedly, at a low strain
of 50%, aged vinyl glove showed a significantly high fatigue life. This
unexpected result was due to the relatively high permanent set that the
aged vinyl glove experienced during the test. In general, aged natural rubber
gloves regardless of the nature of their finish showed much superior fatigue
life values when compared to unaged nitrite or vinyl gloves.

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