@article { author = {Zare Bidoki, Farzaneh and Ezazshahabi, Nazanin and Mousazadegan, Fatemeh and Latifi, Masoud}, title = {An Overview of Protective Gloves with Regards to Hand Performance and the Evaluation Methods}, journal = {Journal of Textiles and Polymers}, volume = {9}, number = {3}, pages = {3-20}, year = {2021}, publisher = {ITAST (Iranian Textile Association of Science and Technology)}, issn = {2322-5203}, eissn = {2423-3390}, doi = {}, abstract = {Many tasks are carried out with the use of hands in various environments and working conditions, so protective gloves are widely utilized by workers voluntarily or as needed. The present study aims to introduce the hand, its various parts, and the importance of protecting the hands, which are subjected to several mechanical and perceptive situations. Moreover, the literature introduces the types of protective gloves, their design and structure. The factors affecting the performance of protective gloves and their evaluation methods are also included. This paper contains two parts; the first part is allocated to overview the importance of protective gloves and the second part is assigned to the published researches in each field and their results are elaborated. By probing the results of the previously conducted researches on protective gloves, it was found that wearing protective gloves often reduced the strength capability of the hand, tactile sensitivity, manual dexterity and range of motion, while the discrepancy in the results of some functions, such as pinch or torque, was observable in the studied researches. Examination of hand performance measurement tasks also showed weaknesses and shortcomings in some methods, and this was one of the causes of contradictions in the results of studies. }, keywords = {}, url = {http://www.itast.ir/article_136072.html}, eprint = {http://www.itast.ir/article_136072_a9ee4f6afc6c210e7fec3276fb6f01aa.pdf} } @article { author = {Daneshvar, Elahe and Amani Tehrani, Mohammad and Zeighami, Fatemeh}, title = {Multi-dimensional Analytical Base Method for Evaluating Camouflage Patterns}, journal = {Journal of Textiles and Polymers}, volume = {9}, number = {3}, pages = {21-28}, year = {2021}, publisher = {ITAST (Iranian Textile Association of Science and Technology)}, issn = {2322-5203}, eissn = {2423-3390}, doi = {10.48302/jtp.2021.136075}, abstract = { Precise evaluation of camouflage patterns is very important to achieve an effective protective cover. Recently, researchers have focused on proposing computational methods for camouflage evaluation using algorithms of image feature extraction. Although the available indexes determine the similarity of camouflage patterns to the environmental background, they generally suffer from a lack of quantified camouflage principles. The main idea of this paper is to propose a new evaluation metric by defining seven camouflage factors to evaluate camouflage patterns. To this end, several conceptual factors of camouflage that are vital for a camouflage pattern were defined. Accordingly, if a pattern does not contain the mentioned camouflage factors, it cannot be considered as an effective protective pattern. In this regard, if a pattern comprises more of the camouflage factors, it has better efficiency in concealment. To indicate the performance of the proposed metric, we analyzed the effectiveness of different customary camouflage patterns using the fundamental factors to categorize them into three different classes including inefficient, moderately efficient, and efficient. The results showed that the camouflage evaluation with the proposed camouflage features is reliable and reasonable.}, keywords = {}, url = {http://www.itast.ir/article_136075.html}, eprint = {http://www.itast.ir/article_136075_0e02229076704994a5665941cf52d789.pdf} } @article { author = {Ghorbani, Vahid and Asgharian Jeddi, Ali Asghar and Dabiryan, Hadi}, title = {Role of Fabric Structure on the Second Tensile Elastic Modulus of Net Warp-Knitted Fabrics}, journal = {Journal of Textiles and Polymers}, volume = {9}, number = {3}, pages = {29-36}, year = {2021}, publisher = {ITAST (Iranian Textile Association of Science and Technology)}, issn = {2322-5203}, eissn = {2423-3390}, doi = {10.48302/jtp.2021.136076}, abstract = { This work aimed to study the second elastic modulus of net warp-knitted fabrics (NWKF) experimentally and theoretically. Net knitted fabrics were selected to study owing to their wide practical application and also lack of enough attention. Knitted fabrics have two regions of tensile elastic behavior which the initial one refers to the displacement of the elements of fabrics before jamming of the yarns. As soon as jamming takes place completely, the constituent yarns in the structure of fabrics go through tension. In other words, yarns in their spatial configuration resist the applied loads. This resistance is important in the ultimate strength of the fabrics and also in the composite materials reinforced with knitted fabrics. NWKFs were produced using a Raschel knitting machine. Uniaxial tensile tests were conducted in the course and wale directions. The second elastic modulus was measured using a statistical approach. In the theoretical part, a mechanical model based on the configuration of elements of fabrics after jamming status and using Energy method and Castigliano’s Theorem was proposed. The proposed model was used to calculate the second elastic modulus. To validate the model, the authors’ experimental data along with the collected data from the other researches were compared with the calculated values, and the results showed that the proposed model can predict the modulus reasonably. The results showed that the fabric structure including wale spacing, course spacing, and the number of lapping movements creating the holes affects the second elastic modulus despite the accepted concept, but the mechanical properties of yarns only influence the second elastic modulus of the fabrics. }, keywords = {}, url = {http://www.itast.ir/article_136076.html}, eprint = {http://www.itast.ir/article_136076_c03d1deeb16089fd0855cf4c3f7a36e3.pdf} } @article { author = {Razbin, Milad and Jamshidi Avanaki, Mostafa and Asghariyan Jeddi, Ali Asghar and Dabiryan, Hadi}, title = {Maximum Negative Poisson’s Ratio of Double-Core Helical Auxetic Yarns Under Uniaxial Loading: A Study on the Effect of Structural Parameters via Full Factorial Experimental Design Method}, journal = {Journal of Textiles and Polymers}, volume = {9}, number = {3}, pages = {37-44}, year = {2021}, publisher = {ITAST (Iranian Textile Association of Science and Technology)}, issn = {2322-5203}, eissn = {2423-3390}, doi = {10.48302/jtp.2021.136077}, abstract = {Auxetic textiles have been attracted the attention of many researchers due to their enhanced mechanical behavior during loading condition. The developed Double-core helical auxetic yarn (DC-HAY) is a structural material with negative Poisson’s ratio (NPR) behavior. It consists of two similar soft yarns with a higher diameter and a stiff yarn with a lower diameter. The stiff yarn has been twisted around the soft yarns, alternatively. In this paper, the effect of structural parameters including, the initial helical angle of wrap component with five levels, diameter ratio of components with three levels, and modulus ratio of components with two levels, on Poisson’s ratio of DC-HAY, has been investigated through the full factorial experimental design method. SPSS software has been used for analyzing the results. The results showed that the highest maximum NPR belongs to the sample with the lowest initial helical angle, highest diameter ratio of components, and highest modulus ratio of components. Also, it has been found that all the main factors have a statistically significant effect on Poisson’s ratio of DC-HAY at a 95% of confidence level.}, keywords = {}, url = {http://www.itast.ir/article_136077.html}, eprint = {http://www.itast.ir/article_136077_8b727b1a728c4a9e1f49fe0e5d981766.pdf} } @article { author = {Vinod Vishwakarma, Sandeep and Kulkarni, S.G.}, title = {Metallocene and Ziegler-Natta Catalysts}, journal = {Journal of Textiles and Polymers}, volume = {9}, number = {3}, pages = {45-50}, year = {2021}, publisher = {ITAST (Iranian Textile Association of Science and Technology)}, issn = {2322-5203}, eissn = {2423-3390}, doi = {10.48302/jtp.2021.136078}, abstract = { Fifty years ago, Karl Ziegler and Natta won the Nobel Prize for their discovery of the catalytic polymerization of ethylene and propylene using titanium compounds with aluminum-alkyls as co-catalysts. Polyolefins are constantly growing and are now one of the most important highconsumption polymers. New metallocene/methylaluminoxane (MAO) catalysts have made it possible to synthesize polymers with highly defined microstructure, tacticity and steroregularity, such as long chain branched or block copolymers with excellent properties. Melt spinning of the fibers of metallocene-catalyzed isotactic polypropylene (PP) and standard equivalent of Ziegler-Natta isotactic polypropylene and therefore the properties of PP and several thermal and mechanical properties of fiber have been investigated. Ziegler-Natta catalysts were prepared by a reaction method which employed Mg(OEt)2 as a precursor. Newly developed metallocene-catalyzed PP possesses higher isotacticity and crystallinity than commercial ones, so the mechanical properties of the final product are guaranteed.}, keywords = {}, url = {http://www.itast.ir/article_136078.html}, eprint = {http://www.itast.ir/article_136078_986c08837705f229adb78b52855676a9.pdf} }