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Polyurethane foams processed according to a hybrid mechanical-chemical-thermal (M-Ch-T) process developed at Air Force Institute of Technology (AFIT) have been tested to verify the inner structure deformation after the process. The X-ray microtomography of both the original EUROFOAM S28280 foam and the processed specimens allowed the creation of three-dimensional virtual models of tested specimens and enabled evaluation of homogeneity of foam structures. In order to examine variations in the processed material's inner structure, samples from different locations of the specimen were scanned. Moreover, a foam specimen was divided into nine subspecimens to perform a set of static tests on each of them separately and to check the gradient of properties throughout the sample volume. Presented methods allowed to visualize the inner structure of the processed foams as well as to estimate inhomogeneity. Obtained results will be used for optimization of the manufacturing process. [ABSTRACT FROM AUTHOR]

Auxetic materials exhibit counterintuitive and interesting properties, which can be utilized to develop new families of products, which can meet sophisticated needs. Study presented within this paper is focused on manufacturing and testing auxetic polyurethane foams for potential introduction for seats in military helicopters. Firstly, a manufacturing process was developed which benefits from the well-known methods of processing conventional foams and allows preparing necessary test specimens for further tests. Secondly, a series of static and dynamic tests was performed during which the market available conventional foams used in transport are compared with processed auxetic foams. [ABSTRACT FROM AUTHOR]

The back‐cover article by Lisiecki et al. (pp. 314–320) presents various tests carried out on auxetic foams developed in the Air Force Institute of Technology (Warsaw, Poland) according to a novel Mechanical‐Chemical‐Thermal process. The tests were aimed at estimating the difference in structure as well as mechanical properties of the manufactured foam specimens throughout their volume. Therefore the processed foams were divided into subspecimens and tested separately. Within the article a detailed insight into the structure of conventional as well as auxetic foams is presented and the most important differences are highlighted. The thesis of the article is that the difference in mechanical properties is highly dependent on the volumetric compression ratio which is the characteristic parameter of the manufacturing process. Obtained results will help to adjust the M‐Ch‐T process in order to achieve more uniform foams or foams with tailored properties. Financially supported by Structural Funds in the Operational Programme – Innovative Economy (IE OP) financed from the European Regional Development Fund – Project “Modern material technologies in aerospace industry”, Nr. POIG.01.01.02‐00‐015/08‐00. [ABSTRACT FROM AUTHOR]