Prof. Raj Das
Abstract: The paper examines the evaluation of a new foam material (known as Hygroflex) in relation to its mechanical properties compared to a number of existing foams. The primary aim was to evaluate Hygroflex foam in regard to pressure redistribution under body induced deformation. More specifically, it explores Hygroflex’s pressure redistribution capacity for mitigation of pressure ulcer development due to long exposure to medical mattresses. The mechanical properties tested were those which play a vital role for use of foam in mattresses, especially medical mattresses used in hospitals. Five different variants of foam were subjected to different mechanical tests in order to evaluate their performance in relation to deformation and stiffness under simulant body part induced loadings. For example, loads exerted by a hip or ankle were replicated using simulant body parts, and the corresponding; deformation, contact development and pressure distribution around the respective simulant body parts were recorded. The properties of interests were; the peak pressure generated, pressure re-distribution over the immersed surface of the foam in contact with the simulant body part, and the immersion and wrap effects under body part induced deformation. The mechanical tests conducted were; a sharp indentation test, an envelopment test, a bulbous indentation test, shear tests, a roller arm test, and a cyclic test. A thermal test was also conducted to assess the heat dissipation ability of the various foams. The test results demonstrate that the newly developed Hygroflex foam has superior mechanical properties required in medical mattresses.