جستجوی مقالات مرتبط با کلیدواژه "آهار نشاسته" در نشریات گروه "صنایع چوب و کاغذ"

Surface sizing of historical papers by starch sizing was performed with the aim of investigating the effect of this material on the aesthetic and mechanical properties of historical papers. For this purpose, starch sizing with a weight concentration of 3% were used and pH, colorimetric, angle of contact and tensile strength tests were performed before and after aging of the samples. The results showed that the pH of samples non-sizing and samples containing starch sizing decreased after aging but it is still in the alkaline range. The brightness of the samples was slightly reduced after sizing with starch before and after aging and the color of the samples tends to darken. Tensile strength of paper samples containing starch sizing before and after aging increased compared to samples non-sizing. The results of measuring the angle of contact also showed that starch sizing no effect on increasing the resistance of paper to wetting and does not prevent the surface of the paper from getting wet.

This study aimed to evaluate cellulose nanofibers and study the effects of these material on starch sizing as the most commonly used sizing in historical paper relics and its use as strength enhancer to restore tensile strength and durability. This research was conducted by analytical comparisons method and samples were collected by experiments related to research topics such as pH measurement, calorimetric and the measurement of tensile strength of the samples. In this study, treatment of cellulose nanofibers with weight percentages of 0.5, 1 and 2%, was prepared as a suspension with water and used to treat the samples containing starch sizing and without it. The results showed that the tensile strength of non-sizing and starch- sizing samples increased after treatment but after aging, the tensile strength of the samples containing starch- sizing decreased slightly. The highest tensile strength after treatment was observed for samples containing starch sizing with 2% treatment at 36 Nm/g and after aging, for non-sizing samples with 2% treatment at 28.2 Nm/g. PH value of non-sizing samples after treatment ranged from 6.98 to 7.17 and after aging, it still remained within the neutral range of 6.85 to 7.11. pH of samples containing starch sizing after treatment was within the neutral range from 7.36 to 7.42 and after aging also remained within the range of 7.16 to 7.19. Examination of the color changes of the samples showed that after treatment of non-sizing and starch- sizing samples, the color of the samples is brighter. After the aging, the color of both groups of samples became darker and it tends to yellowing. However, the color changes in the samples containing starch sizing was less than the non-sizing samples.