Quarterly Scientific-Research Goljaam

In this research, an apparatus was designed and constructed in order to simulate the storage behavior of hand-woven carpet under different environmental conditions. Silk hand-woven carpet (“Gom”) with 115×75 cm dimensions and 102×97 knot per 10 cm was selected and then inserted into the packing simulator with two different laying configurations including flat and folded. The environmental conditions was adjusted at 3 different conditions including 25 ± 5% r.h and 30 ± 2°c (July-Tehran-Dry), 65 ± 5% r.h and 6 ± 2°c (February-Tehran-humid), 40 ± 5% r.h and 19 ± 2°c (October -Tehran-mild). The carpet sample was compressed under constant loads of 135 and 150 kg. The variation of carpet thickness with time in different parts of carpet was continuously measured using data acquisition system. The result of experiment shows that the carpet thickness is suddenly decreased at a short period of time and then reached to a stable condition. The variation trend of carpet thickness with time is accordance with a logarithm equation(y=a×Ln(t)-b) which is highly in agreement with Eyring model proposed in creep theory . But at the dry conditions, the variation of carpet thickness at the folded point follow a non-linear power equation (y=a×(t)^b) with a low correlation coefficient. However, the variation of carpet thickness at the non-folded point and flat configuration is very low.
Generally, at the humidity condition, maximum carpet thickness variation occurred at folded point with folded configuration. On the other hand, carpet thickness variations at dry condition are less those of at humidity and mild conditions. In addition, carpet thickness at dry condition more quickly reached to stable condition than those of at humidity and mild conditions.

To study the way of folding handmade carpets, the selected sample has been put under pressure of 50g/cm2 weight at three different states. The pressure has increased uniformly and continuously at 100,200, 500, 1000 and 1500 g/cm2. The thickness of the carpet has been recorded continuously during the measurement of the thickness of the carpet sample. The pressing parameters of the carpet have been calculated in KES-F system with simulation and fitting of two components model of de-jong pressure. Also, the thickness of the part that is not able to be pressed is estimated. Based on the obtained results, it has been shown that pressing energy in the curved folded part of the carpet is very low, but the pressing energy in the part with two layers of the carpet on each other is very high. Nevertheless, the percentage of elasticity in two layers of the carpet placed on each other is remarkably low. It shows that the sensitivity and flexibility of this area is more in comparison with two layers of the carpet. On the other hand, the thickness of the part that is not able to be pressed in the area with two layers of the carpet on each other is more than that of the investigated areas. In this way, the pressing is carried out by piercing the upper naps on the lower ones. Without folding and flatting of the carpet, it is not pressed and just upper layer naps are pressed on the lower layers. In this study, the phenomenon of Domino folding is used to describe the folding behavior of the handmade carpet under static pressing

If a carpet is put under pressure during use or storage, its thickness decreases instantly and continues to decrease slowly as the pressure is not removed. Some part of this loss of thickness is not recoverable. This phenomenon is called creep and is influenced by parameters such as temperature and humidity, and it may cause breakage, burst, crease, bump, and folding line in the carpet. By studying creep of carpets, it is possible to predict their behavior under such loads to reduce the damages and effects of the creep. In this paper, a sample of folded–carpet is put under pressure of a 170 kg dead weight for 48 hours and its compression strain under various thermal and humidity condition is measured on-line. Then different statistical models were regressed on the collated data proving that creep-model of Voight-Kelvin is assumed as the best formula for determination of creep behavior of the folded carpet under different thermal and humidity conditions. Analysis of data variance detected a significant difference between various levels of thermal and humidity parameters in creep model implying their direct influence in the equation, although they are negligible compared to time effect. This research extended to calculate the Young modulus, creep constant and viscosity coefficient of the folded-carpet.