Quarterly Scientific-Research Goljaam

The existing standards for measuring carpet properties consider carpet behavior after loading while its dynamic and instantaneous behavior is neglected. To investigate the dynamic behavior of under loading carpets, an INSTRON machine equipped with a developed system was used. The reliability of the system was verified by testing different materials. Different samples of hand-knitted carpet with 30, 40, 50, 60 and 70 Raj (rows/6.5cm), with specific structural and physical characteristic and raw material, were tested to obtain the curves of their pressure resistance versus time. The relation between features derived from the load/time curves and carpet structural and physical characteristics and raw materials were defined. Measuring the Pearson coefficient correlation, the linear correlations were studied and analyzed. The results indicate that with increase in knot density (Raj), the rate of decreasing thickness during loading, the resilience of carpet pile after loading, the total work exerted to carpet for reaching to jamming phase and the work returned by carpet during recovery phase decrease; while with increase in carpet thickness, the resilience and the total work increase. In addition, the load/time curves of different materials and hand-knitted carpets were compared. The similarities and differences between their behaviors were derived and the desirable compressibility behavior of a carpet is accordingly suggested.

In addition to medical recognition applications, X-ray CT-scan images are increasingly found to have more innovative and widespread applications. Due to the ability of producing high resolution and high contrast images from soft tissues with low attenuation coefficients, the usage of X-ray micro-focus source, which has a very small focal point (in the range of micrometer), plays an important role in those new applications. Since employing non-original knots in hand-knitted carpet reduces the carpet quality and the originality of knots cannot be visually recognized, in this research, a method has been introduced for recognition of the 3D structure of hand-knitted carpet using CT-scan images provided by micro-focus X-ray source. The images obtained by inverse Radon transform can even show the smallest units in the inner structure of the finest hand-knitted carpets. This method is a powerful device to recognize the originality, to inspect the structure and to study the impacts of different parameters on the structure of hand-knitted carpets and also for other applications which need scrutiny of 3D textiles.

Sharpness of the carpet design is one of the parameters affecting the visual appearance of the carpets. In this paper, some preparatory steps have been taken for measuring the sharpness of the carpet design. First, the influencing parameters on the sharpness of the carpet design have been analyzed and formulated, thus this formula can be used as a theoretical base for measuring the sharpness of the carpet design. Then, by simulation of the carpet design formation, the effect of distinctive steps of carpet product on the sharpness of the carpet design has been studied.