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Mechanical stress is a crucial factor affecting the life and insulation performance of DC-link capacitors (DCLCs). However, at present, there is a lack of long-term experimental observations on the effects of mechanical stress on the life and insulation performance of DCLCs. The element-winding process for DCLCs is carried out by winding metalized film on a reel and adjusting the various winding tensions and pressures according to performance requirements, usually with a winding tension coefficient (WTC) of kT = 1.5. The pull pressure of the winding machine on the film produces tension during the elements' winding process, and the tension in the film grows after the heat-setting process. In this study, by adjusting the four tension coefficients of the elements in the winding process, which were 1.4, 1.5, 1.6, and 1.7, various winding tensions of the DCLC components were changed. Additionally, various heat-setting shrinkage tensions were appropriately generated by setting different heat-setting temperatures (HSTs). Relevant test platforms were established, and a life aging test, insulation resistance measurement, and withstand voltage test were performed on these DCLCs at different tension coefficients and HSTs. The obtained results reveal that the mechanical stress of DCLCs is affected by the parameters of the material itself, including the tension coefficient during the winding process and the HST. The winding tension affects the life of DCLCs, such that those with the highest tension (kT = 1.7) demonstrate the longest life at an HST of 105 °C, whereas samples with the lowest tension (kT = 1.4) exhibit the longest life at an HST of 110 °C. HSTs are capable of improving the lifetime of DCLCs. HSTs are also able to improve the withstand voltage capability of DCLCs, but the tension is not proportional to the withstand voltage capability of DCLCs. This research provides a suitable basis for further explorations of the life and insulation performance of DCLCs. [ABSTRACT FROM AUTHOR]

In view of the problem that the heat setting technology of Lyocell filament was not clear, Lyocell washed filaments were prepared by dry-jet wet spinning technology and the effects of heat setting tension, temperature and time on the mechanical properties and dimensional stability were investigated. The crystal, orientation and micropore structure of Lyocell filaments were analyzed by means of wide angle X-ray diffraction, small angle X-ray scattering and birefringence, and the relationship between structure and properties under heat setting was clarified. The results show that the moisture in the filaments can be removed when the washed filaments are heat-set at 100-130 °C for 3 min. During the heat setting process, the crystal structure of the filament changes little while the decrease of micropore size and the shrinkage of chain segments improve the densification and decrease the orientation degree. The mechanical properties cannot be weakened at the tension of 0.5-2.3 cN/dtex and the thermal shrinkage is lower than 0.7%. The heat setting with tension inhibits the disorientation of the cellulose segments effectively and keeps high crystallinity and high orientation of Lyocell filament, which guarantee both mechanical properties and dimensional stability of Lyocell filament. [ABSTRACT FROM AUTHOR]

The rapid development of wearable smart textiles has led to in-depth research on conductive yarns and flexible sensors. The most common conductive yarn on the market is metal-based conductive yarn. Such a yarn and the functional fabrics thereof have excellent electrical conductivity and play an important role in wearable applications. However, various external factors may affect its structure and electrical conductivity in the actual use process. The durability is an important indicator for evaluating such smart textiles.In this paper, to explore the factors affecting the durability of conductive yarns and flexible sensors, five typical metal conductive yarns were selected. Firstly, the effects of washing times, heat setting temperature, and oxidation time on the resistance of conductive yarns were analyzed. The influence of these three factors on the durability of each conductive yarn was expressed by analyzing the change in the resistance of each sample compared with the original resistance at different lengths. Then, considering the difficulty of weaving each yarn and the requirements of fabric performance, 77 dtex silver-plated conductive yarn was selected to weave flexible sensors of different sizes. It was subjected to 30 washing tests, and the active navy blue BF-DB was used for dyeing treatment. By comparing with the original sample, the influence of washing and dyeing on the performance of the sensor was analyzed by the change of equivalent resistance under different horizontal and vertical lines of the flexible sensor.The results show that the three factors have the greatest influence on the electrical conductivity of copper fibers, while the durability is the worst. The copper wire and stainless steel conductive yarn, as a single component of metal filaments, have the smallest resistance change rate and stable electrical conductivity after multiple washing, heat drying under different temperatures and treatment of different oxidation times, indicating that they have good washing resistance, heat resistance and oxidation resistance. The mechanical force of washing will cause damage to the conductive layer on the surface of the metal-coated yarn. When the coating is defective, with the increase in washing times, the resistance of two silver-plated conductive yarns with different densities increases to a certain extent. The thermal shrinkage of nylon-based silver-plated yarns occurs after the heat setting temperature increases. When the yarn is shortened, the contact degree of each particle in the conductive layer increases, so the resistance decreases and the heat resistance is satisfactory. After 20 days of oxidation treatment, the conductivity is significantly weakened, so the oxidation resistance of the silver-plated conductive yarns is poor. The surface morphology of the flexible sensor woven by the 77 dtex silver-plated conductive yarn changes after multiple washing treatments, but its equivalent resistance value decreases due to the reduction of vertical and horizontal dimensions, so its washing resistance is satisfactory. When dyed with reactive dyes, the flexible sensor is in a high-temperature and high-humidity environment. The coil becomes larger after the fiber expands, and the fiber shrinks after cooling to make its size smaller. The equivalent resistance value is reduced to a certain extent, and it can still maintain stable conductivity, indicating that it has excellent dyeing resistance. The experimental results of this paper can provide reference for subsequent research on the factors influencing the durability of conductive materials, and inspiration for the selection of suitable conductive yarns to develop more excellent and stable wearable sensors. [ABSTRACT FROM AUTHOR]

The plenum chamber of a heat setting machine is a key structure for distributing hot air to different air channels. Its outlet velocity uniformity directly determines the heating uniformity of textiles, significantly affecting the heat setting performance. In a traditional heat setting machine, the outlet airflow maldistribution of the plenum chamber still exists. In this study, a novel plenum chamber with an airfoil baffle was established to improve the uniformity of the velocity distribution at the outlet in a heat setting machine. The structural influence of the plenum chamber on the velocity distribution was investigated using a computational fluid dynamics program. It was found that a chamber with a smaller outlet partition thickness had a better outlet velocity uniformity. The structural optimization of the plenum chamber was conducted using the particle swarm optimization algorithm. The outlet partition thickness, the transverse distance and the longitudinal distance of the optimized plenum chamber were 20, 686. 2 and 274. 6 mm, respectively. Experiments were carried out. The experimental and simulated results showed that the optimized plenum chamber with an airfoil baffle could improve the outlet velocity uniformity. The air outlet velocity uniformity index of the optimized plenum chamber with an airfoil baffle was 4. 75% higher than that of the plenum chamber without an airfoil baffle and 5. 98% higher than that of the conventional chamber with a square baffle in a commercial heat setting machine. [ABSTRACT FROM AUTHOR]

In this paper, the relaxation behavior of polylactic acid (PLA) film in the heat-setting stage of biaxial stretching was studied. Firstly, the polylactic acid casting films were stretched synchronously in different ratios. We found that the Machine direction (MD) and Transverse direction (TD) stress relaxation curves exhibited a separation trend with the increase in the stretching ratio, and the relaxation amplitude increased gradually. Then, the stress relaxation curves were fitted by the expansion exponential equation (KWW equation). The results showed that the coefficient used to characterize the homogeneity of stress relaxation increased with the increase in the stretching ratio, and the homogeneity in Machine direction was better than that in Transverse direction. Finally, we analyzed the evolution of rheological units and the activation energy spectrum during stress relaxation. We found that the volume of rheological units gradually decreased with the increase in the stretching ratio. The activation energy spectrum exhibited a Gaussian distribution, and the symmetry axis of distribution curves shifted to the high energy. The above results would be of great significance in further understanding the deformation mechanism of polylactic acid film during biaxial stretching and providing theoretical guidance for the preparation of high-performance BOPLA films.

Heat equations such as heat flux and thermal conduction were applied in this paper so that these values were obtained during heat setting. Cotton spandex woven fabrics have the properties of stretch ability like stretch, growth, elasticity etc. Due to controlling such types of properties heat setting is mandatory. The values of heat flux and thermal conduction would be beneficial to heat application the fabrics more accurately. A heavy weight stretched woven fabric of twill weave was used in this research. The width of the fabric was 60 inch and had a thickness of 2.5 millimeter. Fabric was heated in a stenter machine with adjusted industrial settings. Heat flux values and thermal conduction values of the clothes were investigated using equations stated in this paper. Overheat can damage the fabrics drastically and all the comfort properties are also influenced seriously. Using heat flux equation and thermal conduction equation, fabrics are heated preciously and all these things are practically analyzed, examined and investigated in this research. This research is trial based and the findings are useful to the employees functioning in textile factories who are in duty of heat setting the cotton spandex woven fabrics and to controlling of their all comfort characteristics.

Poly(lactic acid) fibre, PLA, is relatively new but has been on the market for several years. Yet there are problems associated with its production, especially the wet process. PLA, like PET, is not a very water absorbing material and has problems in dyeing. This study was focused on investigating the effect of different heat setting conditions on dimensional stability of PLA yarn by varying heat setting duration and tension applied during heat setting. Then, we investigated the effect of different colour depths on dimensional stability and the effect of heat setting pre-treatment on dimensional stability by comparing dyed yarn with different heat setting conditions and without heat setting. The results of dimensional stability and yarn strength under various conditions of heat setting and dyeing were quantitatively analysed and discussed. [ABSTRACT FROM AUTHOR]

The textile sector, an important economic driving force in Antioquia, Colombia, uses great quantities of thermal energy mainly produced by coal combustion, which holds enormous potential for recovery. One of the most common processes in a textile plant is heat setting, which uses a significant amount of thermal energy to adjust the properties of fabrics, such as shrinking, stiffness, pull strength, width, and stretching. In this study, we calculate the mass and energy balances of a stenter and propose a system to recover the energy available in its exhaust gases. The energy recovery potential in this heat setting process is 800.97 kW, which represents 87.2% of the total input energy. Additionally, we evaluate different heat exchangers to recover the available heat and present criteria to select them. Finally, thermosyphons, whose thermal efficiency was theoretically determined here, offer a promising alternative for heat recovery from actual stenters.

Copyright of Dyna is the property of Universidad Nacional de Colombia, Medellin, Facultad de Minas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat-based processes on thermoplastic fibre materials cause the materials to shrink. Knitted fabrics may change their dimensions due to thermal shrinkage of the constituent yarns in the fabric and the change in loop shape. The extent to which the thermal shrinkage of polyester yarn affects the thermal shrinkage of the knitted fabric and the effect of heat on fabric parameters are the focus of this article. The thermal shrinkage behaviour of polyester yarn and the plain knitted fabric made of the same yarns were analysed after subjecting them to dyeing, heat-setting and subsequent heat curing processes. The thermal effects on yarns, the yarns in the fabrics and on the wale and course densities were investigated. Thermal shrinkage in the course direction is highly related to the width-wise extension applied during heat setting and the thermal shrinkage in the wale direction is highly correlated to the shrinkage behaviour of the yarns in hank form. [ABSTRACT FROM AUTHOR]

In the carpet industry, yarn shrinkage is a very important specification, the percent of which being affected by heat-setting parameters, time and temperature. In order to obtain the best uniform appearance of carpets, the shrinkage of pile yarns should be minimum in the carpet sizing process. Inappropriately heat-set yarn may cause undesirable shrinkage and uneven pile height on carpets after the sizing process. It could be useful for manufacturers to understand the optimum condition of heat setting to obtain the low shrinkage of heat-set yarns before weaving. Therefore, a fuzzy logic model was designed to predict the shrinkage percentage of polypropylene yarn in different heat-setting conditions. Time and temperature are taken into account as input variables, and yarn shrinkage is predicted as the output. For validation of the model, yarn samples were heat set over various periods of time, at different temperatures, and finally yarn shrinkages were measured experimentally. The results of the fuzzy model prediction compared to regression results show that the fuzzy results present a good and better match with experimental results, with an acceptable R² = 0.97 and average error (2.59%). [ABSTRACT FROM AUTHOR]

Organic single crystals with elastic bending capability and potential applications in flexible devices and sensors have been elucidated. Exploring the temperature compatibility of elasticity is essential for defining application boundaries of elastic materials. However, related studies have rarely been reported for elastic organic crystals. Now, an organic crystal displays elasticity even in liquid nitrogen (77 K). The elasticity can be maintained below ca. 150 °C. At higher temperatures, the heat setting property enables us to make various shapes of crystalline fibers based on this single kind of crystal. Through detailed crystallographic analyses and contrast experiments, the mechanisms behind the unusual low‐temperature elasticity and high‐temperature heat setting are disclosed. [ABSTRACT FROM AUTHOR]

To investigate the drying characteristics of thin cotton fabric for reducing the energy consumption during the heat setting process, a two-dimensional heat and moisture transfer model considering lateral heat and moisture transmission under the impingement drying condition was developed in this study. The curves of the variation in fabric temperature and moisture content over time were obtained and the results indicate that the drying rate increases with the decrease in the moisture content in the fabric. In addition, non-uniform distributions of temperature and moisture on the fabric over time were obtained. The drying time per unit area on the fabric was found to increase with time. Further, experiments were conducted to test the heat and moisture transfer performance of the fabric, and the experimental results agree reasonably well with the calculations. [ABSTRACT FROM AUTHOR]

Harness cord is widely used in the industries of trademark, carpet, home textile and towel, which is the most important lifting part in the jacquard loom. In this article, the tensile properties and crystallization performance of core and sheath fibers in harness cords were measured separately. The influence of heat setting during the finishing process on the fibers' properties was studied. The results showed that the tensile strength, elongation at break and specific work of core fibers were higher than that of sheath fibers. This was because the crystallinity and preferred orientation of fibers were changed by the heat and applied tension during the heat setting process. The core fibers showed better crystallinity, preferred orientation and crystallite size than that of sheath fibers. Besides, the tensile properties and crystallization performance of fibers before and after heat setting was compared. It revealed that the heat setting enhanced the tensile properties and crystallization performance of core fibers, while the opposite phenomenon was observed in sheath fibers. [ABSTRACT FROM AUTHOR]

The paper discusses the design of the oven device, made on the basis of semiconductor thermoelectric converters. The proposed design enables high-precision temperature-stable elements of the REA.

Copyright of Journal of the Tianjin Polytechnic University / Tianjin Gongye Daxue Xuebao is the property of Journal of Tianjin Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat setting has important effects on mechanical and structural properties of polypropylene(PP) mesh. However, there is no systematic study on the effects of heat setting. In this paper, the orthogonal array was designed for heat setting, and the influences of heat setting on structural, mechanical properties and flexural rigidity of PP mesh were studied. The experimental results showed that temperature had larger influence than tension and time on thickness, tensile strength, bursting strength, tear strength and bending stiffness of PP meshes, except the fabric weight The optimum heat setting parameters were as follows : temperature was 120 °C,time was 10 min, and tension was small. These results will provide guideline for the selection of heat setting parameters. [ABSTRACT FROM AUTHOR]

Copyright of China Textile Leader is the property of China Textile Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polypropylene (PP) composites containing poly(ethylene terephthalate) (PET) fibers were prepared by injection molding in the temperature range of 190–260 °C. Increasing processing temperature led to the shrinkage of the PET fibers caused by the relaxation of orientation and recrystallization. Structural changes in the fibers resulted in the deterioration of composite properties. Decreased fiber length and modified local stress distribution restricted the plastic deformation of the matrix resulting in the very poor impact resistance of about 1 kJ/m2 at 260 °C processing temperature. The heat setting of PET fibers resulted in more stable crystalline structure and thus decreased shrinkage and improved composite properties even at high processing temperatures. PP composites impact modified with PET fibers are suitable structural materials for the automotive sector with a sufficiently large stiffness of around 2 GPa and an impact resistance larger than 20 kJ/m2 if processing temperature is kept as low as possible. [ABSTRACT FROM AUTHOR]

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bu çalışmada kendinden uzamalı katedırlar üretilip analiz edilmiştir. Katedırlar üç boyutlu saç örgüsü yapısında olup, polimer yada metal malzemeden imal edilirler. Bu tip yapılar tıbbi alanda tıkanmış olan atardamarların açılmasında merkezden dışa dogru bir kuvvet uygulanması prensibine göre kullanılır. Katedır tarafından damar çeperlerine uygulanan kuvvetin damarlara bir zarar vermeyecek miktarda olması zaruridir. Bundan dolayı, bu tür üç boyutlu hortumsal saç örgülerin yapısı tıbbi uygulamalar için optimum radial kuvvet elde edilebilmesi için incelenmiştir.

The polypropylene (PP) microporous membrane has been used in the Lithium battery as a separator. During the charge and discharge process, the temperature in the battery may rise. To clarify the microstructure change mechanism of membrane during the temperature increase, the PP microporous membranes were heat treated at different temperatures and the microstructure and properties were characterized using differential scanning calorimetry, scanning electron microscopy and atomic force microscopy. When the membranes were treated at temperatures lower than 130 °C, no apparent dimension and microstructure changes were observed. The Gurley value (characterizing the air permeability) was kept around 240 s. When the membranes were treated at temperatures higher than 140 °C, apparent dimensional shrinkage and the decrease or even disappearance of connecting bridges appeared. The corresponding Gurley value was increased to 1320 s, indicating worse air permeability property. The final heat-setting stage during the preparation of microporous membrane based on melt-stretching mechanism could stabilize the stretched connecting bridges and when the heat-treatment temperature was higher than heat-setting temperature, the crystals formed during heat setting could not support the stretched connecting bridges and resulted in the retraction or even disappearance of connecting bridges. These retracted connecting bridges were converted to new crystalline nodes sitting on both sides of separated lamellae. [ABSTRACT FROM AUTHOR]

In this article, a novel method for evaluating the pinpoint effect of pile yarns of carpet is introduced. The method was initially accomplished by presenting a standard method for bundle preparation. Afterward the changes in free spaces between yarns in bundle cross section introduced as an index for evaluation of the degree of pinpoint effect of heat-set yarns on carpet appearance. To achieve the objectives of this research, yarns of different twist were heat set at various times and temperatures. The ratio of free space between yarns to the total area of the bundle was obtained using image processing technique and defined as the index of pinpoint effect. Taguchi method of experiments design was applied to investigate the effect of the mentioned controllable factors of heat-setting process on pinpoint effect of pile yarns of carpet. The results established that increasing the twist, time, and temperature positively contributes on pinpoint effect. Higher twists, times, and temperatures create a jam structure resulting in higher packing density of the yarn and better pinpoint effect. The results of objective method are in good agreement with those of subjective method. Consequently, the objective method of calculating the pinpoint effect can be used as a reliable method to evaluate the pinpoint effect of pile yarns on carpet appearance. [ABSTRACT FROM PUBLISHER]

This article describes a new process for strengthening natural silk fibers. This process is simple yet effective for mass production of high strength silk fibers, enabled by drawing at a lower temperature and immediately heat setting at a higher temperature. The processing conditions were investigated and optimized to improve the strength. Silk fibers drawn to the maximum ratio at room temperature and then heat set at 200 °C show best tensile properties. Some salient features of the resulting fibers are tensile strength at break reaching 533±10.2 MPa and Young's modulus attaining 12.9±0.57 GPa. These values are significantly higher than those of natural silk fibers (tensile strength increased by 44 % and Young's modulus by 135 %). Wide-angle X-ray diffraction and FTIR confirm the transformation of silk I to silk II crystalline structure for the fiber obtained from this process. DSC and TGA data also provide support for the structural change of the silk fiber. [ABSTRACT FROM AUTHOR]

A new method for evaluating the pin-point effect of pile yam of carpets before weaving has been introduced. The method has been initially accomplished by presenting a standard method for bundle preparation and consequently the pin-point index is presented by image analysis technique. To this end, yams with different twists are heat set at various times and temperatures. Comparison of the results shows that increasing the twist, time and temperature positively contribute to the pin-point index. In the last section, an adaptive neurofuzzy model (ANFIS) and an artificial neural network model (ANN) have been designed to predict the pin-point index of the heat set yarns based on training with the experimental data. The input parameters are twist, time and temperature, and the output is the pin-point index. The results illustrate that the learning capability of the ANFIS model is superior and its generalization ability is slightly better than that of a standalone ANN model. [ABSTRACT FROM AUTHOR]

In this paper, carpet comfort has been evaluated from the subjective and objective point of views in relation to the pin-point effect of pile yarns of carpets. For doing judgment on the carpet comfort before weaving the carpets, bundle comparison method has been suggested and a standard method has been presented for the bundle preparation. This research focused to find the best pile yarns twist and heat set conditions to obtain optimum condition for heat set carpets. To achieve the objectives of this research, yarns of different twist were heat set at various times and temperatures. Taguchi method has been used as the method for the design of the experiments, then the effect of the controllable factors of heat setting process in the comfort of carpets has been investigated. Observers did test the both comfort and aesthetic of yarn bundles and both compression modulus and expenditure energy have been calculated as the subjective and objective methods, respectively. Objective evaluation has been done based on the earlier researches results that defined more carpet comfort could be achieved in pile samples with lower compression modulus. Consequently, the optimum heat setting parameters have been achieved by an outlook on Taguchi results and constraint analyses by response surface methodology. [ABSTRACT FROM AUTHOR]

In the present paper, a response surface model has been introduced to predict the geometrical parameters of heat set polypropylene pile yarns. The input factors of the presented model include yarn twist, initial yarn count, time, and temperature of heat setting and the response factors are yarn count, yarn shrinkage, crimp contraction and packing factor after the heat setting process. To analyse the effect of this process on the yarn parameters, the dry heat setting process has been applied to all samples at different times and temperatures using an oven equipped with air circulation because of better accuracy and control of temperature. The obtained results showed that there is a positive relation between time and temperature and output parameters. Finally, the predicting equations discussions about the optimum points for maximum shrinkage and interactions of parameters have been presented. Hence, due to some disability of the RSM method, an ANN model has been designed to predict the parameters at higher accuracy. The results of the accomplished ANN model represent a higher prediction correlation coefficient compared to RSM. [ABSTRACT FROM PUBLISHER]

Copyright of China Textile Leader is the property of China Textile Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Textile & Apparel / Tekstil ve Konfeksiyon is the property of Tekstil ve Konfeksiyon and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)