Abstract
The article covers the technology of computer modeling of technological processes on example of the research of transverse oscillations of the thread in weaving process. During the formation ...of the fabric, various dynamic processes took place, including fluctuations in the threads. As an example, the longitudinal oscillations and tension of the threads in the process of surf on a loom are considered. The program and the results of the calculation are given using the software package “Mathcad”.
Fibre lithium-ion batteries are attractive as flexible power solutions because they can be woven into textiles, offering a convenient way to power future wearable electronics
. However, they are ...difficult to produce in lengths of more than a few centimetres, and longer fibres were thought to have higher internal resistances
that compromised electrochemical performance
. Here we show that the internal resistance of such fibres has a hyperbolic cotangent function relationship with fibre length, where it first decreases before levelling off as length increases. Systematic studies confirm that this unexpected result is true for different fibre batteries. We are able to produce metres of high-performing fibre lithium-ion batteries through an optimized scalable industrial process. Our mass-produced fibre batteries have an energy density of 85.69 watt hour per kilogram (typical values
are less than 1 watt hour per kilogram), based on the total weight of a lithium cobalt oxide/graphite full battery, including packaging. Its capacity retention reaches 90.5% after 500 charge-discharge cycles and 93% at 1C rate (compared with 0.1C rate capacity), which is comparable to commercial batteries such as pouch cells. Over 80 per cent capacity can be maintained after bending the fibre for 100,000 cycles. We show that fibre lithium-ion batteries woven into safe and washable textiles by industrial rapier loom can wirelessly charge a cell phone or power a health management jacket integrated with fibre sensors and a textile display.
This article presents the dynamic modeling and analysis of an electric motor with integrated magnetic spring (EMMS) when it is coupled to a weaving loom application. The EMMS can provide the majority ...part of the oscillating part of the load in a passive way by the magnetic spring. The electric motor provides the average torque and the remaining oscillating part in an active way. This reduces the energy consumption. To create an accurate dynamic model for the EMMS, lookup tables are generated from a finite-element model. Further, a 4-bar linkage mechanism is employed to emulate the behavior of the shedding mechanism of a real weaving loom application. Eventually, the whole system dynamic model was created in Matlab environment. Moreover, a complete experimental setup was constructed to validate the effectiveness of the proposed dynamic model and the EMMS behavior. It is shown that the proposed dynamic model effectively predicts the performance of the EMMS system. Besides, it is proved that the EMMS can effectively reduce the energy consumption of the weaving loom application. The amount of reduction in the energy consumption depends on the designed magnetic spring. For the considered application, it can reach 57%.
This paper compares three drivetrains for the shedding mechanism of weaving loom applications, which have a strongly oscillating load pattern. The three drivetrains employ a permanent magnet motor ...without a gearbox. The first drivetrain uses only the electric motor (EM1) while the other two drivetrains use the electric motor with assistance of a separate or an integrated magnetic spring (EM2MS or EMMS respectively). The magnetic spring provides part of the load torque in a passive way. This results in a reduced power consumption. The optimal design and the performance analysis of the machines have been presented for the considered application using a 2D finite element model coupled with an optimization algorithm. To validate experimentally the theoretical results, the EMMS prototype is manufactured and tested with and without an external load. The employed load is a 4-bar linkage that emulates the behaviour of a shedding mechanism of a given weaving loom. It is found that employing a magnetic spring can effectively reduce the power consumption of the drivetrain by more than 40%. However, introducing the magnetic spring reduces the flexibility of the system. In addition, it increases the initial cost. Nevertheless, the higher initial cost of the drivetrain will be paid back by the lower energy consumption.
Traditional proportional–integral–derivative (PID) control performance optimization is an essential method to improve a loom’s warp tension control performance. This work proposes an improved genetic ...algorithm optimized PID control scheme to overcome the decline in control performance of the traditional PID control algorithm in a loom’s warp tension control system. Through the decoupling analysis of loom motion mechanism, the establishment of warp tension model and the optimization of fitness evaluation mechanism of genetic algorithm can effectively overcome the problems of local optimal solution and algorithm degradation of genetic algorithm. Simulation experiments were carried out with the traditional PID, the integral separation PID, and the genetic PID in warp tension control. The results show the advantage of the genetic-PID algorithm to control warp tension stability. Ultimately, according to the functional characteristics of the loom mechanism, a tension control platform for experimental studies was established. The test results show that the maximum fluctuation range of warp tension is within −2, +6 at the test speed of 850 rpm, which meets the requirements of long-term stable and reliable control of warp tension under different weaving conditions.
Woven fabric is produced by interlacing the warp yarn and the weft yarn, and their relationship on woven fabric is represented as a weave diagram. In order to produce woven fabric with looms, the ...necessary number of heald frames can be calculated based on the weave diagram for the woven fabric. However, when the number of available heald frames is limited, it is difficult to produce complex woven fabric. To alleviate this problem, this article proposes a method for approximating weave diagrams under heald frame constraint in terms of the alternating optimization in machine learning. By defining the objective function based on the matrix representation of weave diagram, an alternating optimization method is proposed to generate an approximate weave diagram under the specified number of heald frames. The proposed method is implemented with R language, and evaluated in terms of the performance of the proposed algorithm and woven fabric. Experimental results indicate that the proposed method is effective in generating approximate weave diagrams so that they can be fabricated using looms with a limited number of heald frames.
The combination of the nonlinear rheological models to the simple pendulum in the conditions of the forced oscillations simulates the action of the let-off motion with weights. The experimental study ...considers the dynamic balance during the unfolding of the warp in function of the adjustments of the let-off motion. The stress of the warp threads carries out the mechanical transition from the loom’s adjustments towards the fabric quality. A rotatable plan of factorial experimentation indirectly explores the process of interaction of threads during the intersection.
Background: Workers in the textile industry risk developing various respiratory and pulmonary diseases due to exposure to cotton dust. The particles from the cotton lint are inhaled by the workers ...and results in the breathing problems including asthma, shortness of breath, cough and tightness in the chest. The poor health of labor contributes to the low productivity of the labor and in serious cases loss of jobs leading to the poverty. Objective: To assess the prevalence of respiratory symptoms among the textile workers and associated community. To contrast the health profiles of the textile workers, associated community and the control group to factor out any confounding factors. Methods: This study explores the health profiles of the textile workers and associated community and contrast them against the health profile of the control group to factor out any confounding factors. The study is conducted on cotton industry in Kasur, Pakistan. We interviewed 207 workers, 226 people from associated community (living in vicinities of weaving units) and 188 people for control group (from areas far away from weaving units and people are not associated with weaving industry) based on stratified random sampling technique. We employed descriptive methods and logistic regression to explore the association between respiratory diseases and weaving workers. Results: Overall, prevalence of postnasal drip, byssinosis, asthma, and chronic bronchitis were 47%, 35%, 20%, and 10%, respectively, among the workers. These percentages are significantly higher than the control group. An additional year of work increase the risk of postnasal drip, byssinosis, asthma, and chronic bronchitis by 5–6%. Among workers, 43% and 21% feel difficulty in hearing against noisy background and at low volume, respectively. Due to bad light arrangements at workstations, 21% and 31% workers are suffering from myopia and hyperopia, respectively. Proportions of the workers suffering from continuous headache, skin infection, depression, and low back pain are 28%, 29%, 27%, and 44%, respectively. Chi-square test results confirms that no confounding factor like air pollution is involved in this cause-and-effect study implying the association between the cotton dust and associated diseases is not spurious. Conclusion: Respiratory symptoms were statistically significantly more common in the weaving workers compared to control group. Better environment at workstations, use of protective gears and education are the factors which reduce the risk of associated diseases among workers.
•We examined farmer resilience and vulnerability in the context of climate change.•Patriarchy and local culture shape women's and men's vulnerability to climate change.•Some farmers don’t generally ...worry about climate change.•Long-term historical processes are shaping contemporary impacts of climate change.•Farmers are using incremental social learning to limit climate change impacts.
This paper investigates the relative importance of climate change in the context of multiple stressors in semi-arid Ghana. It draws upon ethnographic research in two agrarian villages, and integrates theories from resilience, vulnerability and feminist political ecology. The findings empirically demonstrate that many farmers do not worry about climate change, even in situations where local perceptions and the climate data show a clear pattern of variability. Additionally, the paper provides evidence of a ‘gendered double exposure,’ whereby patriarchy and local culture shape how different social groups are impacted by climate change. Overall, the emerging findings suggest that an overemphasis on scenario-based climate change impacts may detract attention from equally important non-climatic factors that loom large in people's lives. The article's central argument is not meant to downplay the ongoing impacts of climate change in Africa. It rather suggests that climate change should be addressed as one problem among many socio-ecological challenges facing smallholder farmers.
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