The solar properties of fabrics produced using different weft yarns

2017 ◽  
Vol 88 (13) ◽  
pp. 1543-1558 ◽  
Author(s):  
Kenan Yildirim ◽  
Asuman Kanber ◽  
Mehmet Karahan ◽  
Nevin Karahan

Woven fabric is composed of two yarns system, known as the weft and warp yarns. Each yarn system has an effect on the physical, performance, and optical properties of fabric. Any change in one or both yarn systems greatly alters the fabric properties. The solar and luminous properties of fabrics are also affected by altering the weft yarn or both yarn systems. This study investigates the effect of altering the weft yarn system on the solar and luminous properties of fabrics. The differences in the weft yarn in the fabrics were based on the weft yarn structure, including the yarn linear density, amount of twist on the yarn, yarn evenness, hairiness, spinning method, fiber composition of the yarn, and weft density of the fabric. The fabric luminous and solar properties were measured according to EN 14500 using an ultraviolet-visible-near-infrared (UV/VIS/NIR) test device and calculated from the EN 410 standard test method. According to a variance analysis, the weft density factor is shown to have an effect on the solar properties of the fabric, especially the UV transmittance properties of the fabric. Although non-parametric test results with a 95% confidence level show that the yarn structure does not influence the solar characteristics of the fabric, we show from the test results that the yarn structure influences the solar properties of the fabric. Yarn hairiness was the dominant factor for the IR and visible portions of the solar radiation spectra. In the UV region, the fiber composition factor was found to be important. The effect of the yarn linear density was similar to the effect of the weft density factor. The solar transmittance decreases and the reflectance increases when the number of weft yarns per unit length is increased and the yarn linear density in the Ne numbered system is decreased. Increasing the yarn hairiness decreases the transmittance in the IR portion of the solar spectra. The degree of influence that the yarn structure has on the solar properties (with the exception of the UV portion) of the fabric was dominated by the number of weft yarns per unit length. The transmittance properties of the fabric were more affected by altering the yarn structure than the reflectance and absorbance properties.

1969 ◽  
Vol 39 (11) ◽  
pp. 1038-1043 ◽  
Author(s):  
B. L. Banerjee ◽  
A. Lahiri

From a study of the relationship between the breaking strength and the corresponding mass per unit length at thefracture zone of a yarn, the expected strength of a perfectly even yarn of identical fiber composition has been derived. The ratio between the observed strength and this estimated value has been taken as a measure of utilization of fiber strength in yarn. The dependence of this utilization factor on the diameter irregularity of yarn has been examined on the basis of test results obtained on a number of yarn samples of different qualities. The yarn tenacity at the fracture zone is also found to be related with its diameter irregularity; the causes of this are discussed


2017 ◽  
Vol 88 (9) ◽  
pp. 1065-1076 ◽  
Author(s):  
Tao Hua ◽  
Ngo S Wong ◽  
Wai M Tang

This paper presents a development of elastic core-spun yarn containing a mix of spandex and polyethylene terephthalate/polytrimethylene terephthalate (PET/PTT) bi-component filament as core to obtain better yarn properties, especially for elastic property. Eight types of core-spun yarns, consisting of different core components with various values of linear density and covered with cotton fibers, were produced using a modified ring-spinning machine with a core spinning attachment. The influences of core components, linear density, and draw ratio of spandex on yarn structure and properties were investigated. The experimental results demonstrate that core-spun yarns containing a mix of spandex and PET/PTT bi-component filament have much lower yarn stress decay as well as lower hairiness and CVm value of evenness compared to the yarns using only spandex. For the yarns containing a mix of spandex and PET/PTT bi-component filament, the yarns containing 70 denier spandex have higher elongation and stress decay compared to the yarns containing 40 denier spandex. The test results show that the elongation of yarns containing a mix of spandex and PET/PTT bi-component filament increases with the increase of the draw ratio of spandex. The stress decay of yarns containing a mix of 70 denier spandex and PET/PTT filament shows a similar trend to the elongation. Moreover, the yarn samples containing a mix of spandex and PET/PTT filament as core exhibit good yarn evenness, with very few thick places and neps, as well as low yarn hairiness.


2021 ◽  
Vol 16 ◽  
pp. 155892502198897
Author(s):  
Joy Sarkar ◽  
Md Abdullah Al Faruque ◽  
Moni Sankar Mondal

The main purpose of this study is to predict and develop a model for forecasting the Seam Strength (SS) of denim garments with respect to the thread linear density (tex) and Stitches Per Inch (SPI) by using a Fuzzy Logic Expert System (FLES). The seam strength is an important factor for the serviceability of any garments. As seams bound the fabric pieces together in a garment, the seams must have sufficient strength to execute this property even in the unexpected severe conditions where the garments are subjected to loads or any additional internal or external forces. Sewing thread linear density and number of stitches in a unit length of the seam are the two of the most important factors that affect the seam strength of any garments. But the relationship among these two specific variables and the seam strength is complex and non-linear. As a result, a fuzzy logic based model has been developed to demonstrate the relationship among these parameters and the developed model has been validated by the experimental trial. The coefficient of determination ( R2) was found to be 0.98. The mean relative error also lies withing acceptable limit. The results have suggested a very good performance of the model in the case of the prediction of the seam strength of the denim garments.


2014 ◽  
Vol 496-500 ◽  
pp. 1176-1179
Author(s):  
Li Tan ◽  
Yu Fang

LTX-77 test system is a large IC test system that is used for various kinds of analog IC, digital IC and analog digital mixed IC. It can be used to test DC parameters, AC parameters and logic functions. In the paper, the IC test platform is LTX-77 test system. IC ADC0804 was tested as the test object. The test method of IC is described in the view of actual test. The test results show that the test system is convenient and accurate, which has important practical value for IC manufacturers and users.


2013 ◽  
Vol 275-277 ◽  
pp. 1911-1914 ◽  
Author(s):  
Han Jun Hu ◽  
Hui Zhou ◽  
Yu Gang Zheng ◽  
Kai Feng Zhang ◽  
Zhi Hua Wan

The bonded MoS2 films are widely used as solid lubricants in aerospace mechanisms due to their excellent tribological properties. Traditionally, the MoS2 was directly bonded on the Al substrate that was only treated by the technique named of sandblast. For improving the tribological properties of MoS2 films, micro arc oxidation (MAO) instead of sandblast was introduced as a new technique for treating of Al substrate. In this article, the tribological properties of MoS2 films which were bonded on different surface of Al substrate as mentioned above were discussed, respectively. It was concluded from the test results that the MoS2 films bonded on substrate treated by MAO have better tribological properties than those samples treated by sandblast. The endurance life against abrasion of the former is as high as twenty times of the latter by the stand test method of ball on disk using the UMT Multi-Specimen Test System. This test results could be illustrated by the following reasons. The first is the porous microstructures of MAO ceramic coatings on the Al substrate. The coatings have numerous pits to be good at increasing the binding force with the MoS2 films, and the pits can also provide a MoS2 lubricants reservoir during processes of friction. Both of them improved the MoS2 film’s ability of wear-protective. The second is that hardness of the coating is higher than the Al, and this ensures well wearing resistance, especially in practical application to big load-supporting moving parts, such as bearing, gear, etc…


2013 ◽  
Vol 690-693 ◽  
pp. 2371-2378
Author(s):  
Wei Pu Xu ◽  
Yi Ting Liu

A brief overview is given in the conventional domed bursting disc structure and manufacturing method. 316L stainless steel as a template is selected. With the investigation on bursting disc material tensile test method, the test results are summarized,also the burst results of disc burst pressure in different sizes. With the help of bursting disc material performance test and bursting disc burst pressure test of 316L , the test results provide a reference for other types of bursting disc.


2019 ◽  
Vol 3 (1) ◽  
pp. 34
Author(s):  
Dea Tio Mareta

Instant seasoning for cooking are commonly known by people who want something practical. Pindang is a typical food of Lampung and South Sumatra Province, consisting of various spices and herbs. Instant pindang seasoning powder made with foam mat drying method using 3 varations of foam additives. The purpose of this study was to determine the level of taste, aroma, and color of instant pindang seasoning powder made with three variations of foam additives, namely 5% (w/w), 10% (w/w), and 15% (w/w). The hedonic test for instant pindang seasoning powder were carried out on 35 panelists. Panelists were faced with 3 samples with 3 different sample numbers. Panelists were asked to assess how much preference for seasoning products using hedonic scale. The hedonic test results showed that, with the addition of 15% (w/w) foam is preferred in terms of color. As for aroma and taste, there were no significant differences between the three products. Keywords: foam mat drying , hedonic test, instant pindang seasoning powder, pindang


2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Ismail Marzuki ◽  
Soemardiawan Soemardiawan

The focus of the problem in this research When competing frequently there are mistakes in dribbling, so from this it is necessary to have this exercise, to improve the dribbling skills of PS players. UNDIKMA Mataram. The purpose of this study is to determine whether there is an effect of Dribbling With A Curving Line Trajectory Exercise on the Dribbling Skills of PS Soccer Players. Mataram UNDIKMA 2019 ". The research methods used by researchers are the observation method, the documentation method and the deed test method. The study design uses a pretest-posttest design (initial test and final test). The population used in this study are all PS players. UNDIKMA Mataram in 2019. The number of samples in the study conducted was 22 which became a sample of 11 players PS soccer players. UNDIKMA Mataram. The sampling technique in this study using the saturation sampling technique is a sampling technique if all members of the population can be sampled. Analysis of statistical data with a significance level of 5% for the speed test results obtained by the t-value so from the results of research X1 (Dribbling With A Curving Line Trajectory, with Y1 obtained tcount is much greater than ttable, this shows that the hypothesis "Ha" (accepted ) then this research is significant, drawing conclusions from the table analysis at a significant level of 5% with a number of samples (n - 1) that is 11-1 = 10 at 1,812. Then it can be concluded that, 1) The Effect of Dribbling With A Curving Line Trajectory on Dribbling Skills PS Football Players. Mataram UNDIKMA 2019, Tcount> ttable (7.362> 1,812). 2). this shows that the hypothesis "Ha" (accepted) then this research is significant.


2014 ◽  
Vol 10 (1) ◽  
Author(s):  
Salafudin *

This study aimed to determine: (1) how was the design of character building by learning mathematics, and (2) whether the character building by learning mathematics could produce better learning outcome of mathematics than conventional mathematics learning.To answer these two questions, I used Research and Development ( R & D ) which consists of a preliminary study to obtain preliminary data on student learning outcomes before being given treatments of character building by learning mathematics. The next phase is the design of the character building by learning mathematics. Further testing and revision in class and repeated until it found the best learning model. From the first problem formulation, qualitative data analysis, such as the design of character building in learning mathematics was produced. The results of the qualitative analysis shows, character building by learning mathematics was quite effectively applied to implant positive character in students. To answer the second question, statistical analysis was used. The population in this study was all students of class VII of MTsN in Buaran of Pekalongan which totaled 220. By random cluster sampling technique two classes (a class VII A and VII B) was chosen. Class VII A was as an experiment class, and class VII B was as a control class. Data were taken by the test method, experimental classroom observation, and documentation. The data was then processed with an average difference test. Results of statistical analysis obtained t = 3.33 > t table = 1.67. This meant that learning achievement of the students in the experimental class, which was implemented character education in mathematics was better than the students who were taught by conventional methods. Based on these results, it could be conclude that the character building in mathematics was better than the conventional method of learning mathematics.


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