فصلنامه علوم و فناوری نساجی
سال دوازدهم شماره 1 (بهار 1402)

In this research, silver nano particles were first coated on the surface of jute fibers through simultaneous synthesis method. In this approach, both the synthesis and deposition of silver nanoparticles on jute were carried out in one bath. Then these treated fibers were coated with methyl methacrylate. Scanning electron microscopy (SEM) micrographs showed that the size of nano silver particles was between 29 and 230 nanometers.The use of nano silver particles caused a slight color change in the appearance of the fibers so that the whiteness index decreased and the yellowness index of the fibers increased. The SEM microgrphs showed that the presence of nano silver and methyl methacrylate on the surface of the fibers causes roughness on the surface of the fibers. The reflection values ​​also showed a decrease in the brightness index of the fibers. The values of correlation coefficient showed that the adsorption of metal complex dye onto jute fibers obeys the Freundlich model. The results of the adsorption isotherm tests showed that both the adsorption capacity and the absorption intensity for the metal complex dyes increased due to this type of finishing. Moreover, these finished fibers showed better light and washing fastness compared to the raw fiber.

In recent years, the semiconductor photocatalytic process has a great potential as a low-cost, environmentally friendly and sustainable technology, which is known as zero design in the water and wastewater industry. The ability of advanced oxidation technology is widely used to remove stable organic compounds and microorganisms from water. Currently, the recovery of catalyst particles after water treatment is the main obstacle to the commercialization of this process. In this research, the combination of ozone with ultraviolet rays in the presence of titanium dioxide and also the effect of temperature on the reaction in a discontinuous reactor to separate paratoleic acid from the effluent of the terephthalic acid production unit have been investigated. and also with the increase of the sample temperature due to the decrease in the solubility of ozone gas, it decreased to 10% and also in the presence of titanium dioxide, the removal efficiency decreased and reached 8%.

In this research study, anthocyanin pigments were extracted from Hibiscus sabdariffa L pigment using some solvents including distilled water, citric acid, ethanol and sodium hydroxide. Then the effect of the type of solvent used in the pigment extraction stage on the dye parameters and fastness of the dyed silk fabric was investigated. Pre-mordanting, simultaneous and post-mordanting methods were used for dyeing, and potassium aluminum double sulfate metal salt was used as the mordant. The results showed that although the dyeing process for all the samples was carried out in an acidic environment, the use of different solvents and the change in the pH of the pigment extraction environment caused a change in the created hue, the amount and area of a* and b* and the color strength of the examples. The highest color strength was created in the pre-mordanting method by using the pigment extracted in sodium hydroxide environment, while the lowest one was obtained in the post-mordanting method by applying the pigment extracted in distilled water environment. Also, according to the ISO standard, in the pre-mordanting method, the samples dyed with pigment extracted in sodium hydroxide environment and in the post-mordanting method, all samples had acceptable washing and light fastness.

In ring spinning, the traveller has an important role in yarn properties. After the draft in fibers tape, traveller twist to yarn coordinated by spindle rotation that caused the yarn wind around the bobbin. Therefore, if the weight of traveller was suitable, it will increase the production speed ring and the desired yarn quality. The purpose of this research, is the effects of traveler weight on physical and mechanical properties of polyester/cotton yarns. Also, the estimation of the suitable traveller score to obtain the desired physical and mechanical properties in the rim threads is one of the other goals of the research. Therefore, some examples of the traveller score were considered for polyester/cotton mixed ring yarn. According to the ASTM standard test instructions, repeated tests were performed to reduce the error rate of the tests. Data analysis was done using SPSS statistical software (27) and all comparisons were tested by ANOVA and then Duncan test at 95% confidence level. The results showed that by the increase in traveler weight, the yarn twist, strength and the frequency of thick places in the yarns increase, and the hairiness and thin places in the yarn are decrease. Other results showed, if increase in weight of traveller, the hairiness and thin rate spots in polyester/cotton yarns decreases.

The purpose of the present research is to investigate the shear modulus of the polymer matrix composite. For this purpose, 3D orthogonal fabric was used to strengthen the composite. Threads in the woven structure produced by the orthogonal method have less wrinkling compared to other 3D fabric production methods. Composite samples in two different types, one with a high volume fraction of HVF fibers and the other with a low volume fraction of LVF fibers, were produced with two types of epoxy resin and polyester using the vacuum pump method and were subjected to torsion testing. In the next step, numerical modeling was done in Abaqus software. The results showed that the shear modulus and torsional strength of LVF composite with epoxy matrix increased by 7% and 11%, respectively. Comparison of the simulation results with the experimental method showed that the shear modulus obtained from the modeling had an error of less than 10% compared to the shear modulus of the composite, so the simulation method can be used to predict the mechanical properties of the composite.

In recent years, the advent of laser technology in the textile industry has brought new innovative solutions to processes such as fabric marking and cutting, successfully overcoming many of the weaknesses of conventional technologies. Various factors influence the laser treatment of natural and synthetic textile materials. In this paper, the effective parameters of laser cutting of textiles are presented and analyzed to understand the physical nature of this process and improve its technique. In the following, the experimental results of cutting Fustian fabric with a combination of 45% wool and 55% polyester using a continuous carbon dioxide laser at a wavelength of 10.64 μm are investigated. Experiments on the effect of varying power, cutting speed, and size of beam diameter show that laser light with a beam quality of 1.5 and power of 15 watts can cut 6 layers of Fustian fabric at a speed of 30 mm/s with the desired quality.