Academic literature on the topic 'Yarn quality parameters'

Yarn quality is an essential concept, usually defined by the customers which demands simultaneous achievement of several requirements concerning the yarns characteristics. For the cotton type yarns, the tensile properties represent the most important parameters for assessment of yarn quality, because these features are key factors regarding the yarns behaviour in post-spinning operations (warping, weaving and knitting) and have a determinant contribution to the properties of final textile product. Hence, an accurate prediction of these characteristics is very important, from both technological and economic points of view. Providing the conditions for obtaining yarns with specified characteristics requires suitable selection of fibres used in blends, correct setting of the structure parameters of yarns and the processing conditions of the fibrous material, in close correlation with the yarn's end-use requirements, the manufacturing technology and the technical level of equipment. Finding an optimal variant of fibre blend involves considerable amounts of work, time and money. Therefore, the use of dedicated software for designing fibre blends may contribute to reduce these drawbacks and allows obtaining optimal blend recipes faster and more effective. The paper presents a software application developed primarily as a tool for teaching students the principles of rational design of fibre blends intended for cotton yarns with specified characteristics, but it can be also used by the spinning companies. The PFirB software is part of a package developed to support the teaching activities with the students from the Faculty of Textile-Leather and Industrial Management in Iasi, was created with Microsoft Visual Basic and Visual C++ and runs in a Windows environment.

Nowadays, the manufacture of textile products has become a highly competitive activity and the success across the global textile market depends on many factors. Higher productivity, increased flexibility, constant quality products and quick response to the market requirements are competitive advantages that companies can achieve by using IT instruments. Production of high quality yarns is based on an assembly of technological and mechanical factors that are closely correlated with the characteristics of processed raw material. Designing the manufacturing technology in spinning mills is an important stage within the complex process of yarn manufacturing. It aims at obtaining the spinning plan that ensures the coordination of the equipment's operating parameters and the correlation of its production capacities. Establishing the spinning plan parameters requires a large amount of work and assumes extended knowledge concerning the raw material characteristics, the spinning technology, the type and technical performances of the equipment, the level of yarns quality. Given the diversity and the large volume of data and calculations required to achieve the spinning plan, the efficiency of this activity may be increased by using specialized software designed for this purpose. This paper presents a software application used as a teaching instrument for technological design in spinning mills. The PFirLB software gathers all the information and provides the tools required to design the manufacturing technology in tow spinning mills. It is used for student training in order to teach them the skills for technological design, required by their future work as engineers in a spinning mill. The software was created with Microsoft Visual Basic and Visual C++ and runs in a Windows environment.

Abstract Due to the increasing speed of production, sale, and discard of home and apparel products, recycling of textiles is important for supporting the UN’s Sustainable Development Goal of Responsible Consumption and Production. In 2020, textile production was estimated to be responsible for 35% of primary microplastics released into the environment, 20% of global clean water pollution, and 10% of global greenhouse gas emissions. In 2018 the US generated around 17 million tons of textile waste and only 14.7% was recycled. Drum-operated textile shredding, a commonly utilized mechanical textile recycling technique, is not yet fully characterized. Even though there are many shredding machines that perform this process, the parameters that influence high-quality fiber output have not been researched; discovering ways to improve reusable fiber output is still a challenge. This research investigates the theory behind carded (toothed) drum textile shredding including how to improve the process outcome in order to obtain more reusable fiber and fewer textile pieces and dust. The mechanics of the textiles and fibers under tensile and shear stresses from the drums and drum teeth respectively were described to relate the textile material failure behavior to shredding process fiber outputs. Focusing on the interactions of the feeding drums and shredding drum, the drum-textile and tooth-yarn failure mechanics were characterized. By decreasing the teeth size and increasing the relative speed between drums, it is expected to increase the shear failure ratio, thus improving the shredding system. With this, it is expected that manufacturing new and better materials from recycled fibers becomes a possibility.

This article presents a modern, e-learning method designed for the study of the open-end spinning machine with rotor for processing cotton fibers, blends of cotton and chemical fibers or chemical fibers cotton types. It exposes a new teaching and learning approach of the laboratory for subject Processes and Machines in Cotton Spinning Mill comprised in the academic curricula of the 3rd year students, specialization Technology and Design Textile Products. The open-end spinning machine with rotor is placed at the end of the technological flowchart for manufacturing of unconventional yarns. Within this machine, the band resulted after passing two or three drafting passages, is transformed aiming to improve the quality of the yarn. The main operations carried out in the spinning process comprise: feeding the bands, advanced opener with a opener cylinder until fiber individualization, drafting by means of air flow, twisting of the fibrous reinforcement and winding of yarn and finally wrapping the thread on the bobbin. The work is accomplished in Power Point aiming to capture the attention of the students. Besides, the transition from chapter to chapter or to additional relevant aspects within a chapter is carried out by means of hyperlinks. The kinematic and technological schemes developed on Autocad serve to calculus, kinematic and technological, and facilitate a better understanding of the functioning of the machine, part of the machine or different mechanisms. Supplementary, several images, audio and video files support the learning and understanding process. The video material derive from personal records or from processing available movies in the public space, www.youtube.com, using Adobe Premiere Pro CS6 software. For each kinematic or technological parameter to be calculated, the respective kinematic chains are identified by changing the properties of the respective entities (kind, thickness or color of gears). The paper can be accessed from the official website of the university, http://www.uav.ro/, by accessing the platform on https://core.uav.ro/ containing all the bibliographic materials uploaded for university students are. The access requires a username and password, both for teachers who publish information and for students as users.

The ring-spinning process is an important manufacturing process for the mass customization of clothing goods, especially for large-run yarns. Cop quality is one of the most important characteristics concerning ring-spun yarns. It is mainly evaluated and compared via the diameter of a cop. This study aimed to optimize the ring spinning parameters influencing the cop diameter. The optimization of the spinning process was investigated using the Taguchi method. Using the S/N ratio, the best combination of factor levels that yield the highest value of cop diameter was detected efficiently.

Healthcare workers experience physically, emotionally stressful situations, are exposed to human suffering, experience pressure from interactions with patients and family members, and are under constant threat of infection, injury and stress. Healthcare workers are at greater risk of developing stress-related mental disorders, such as depression or post-traumatic stress disorder (Braquehais et al., 2023, doi:10.1016/j.mcna.2022.04.004). The COVID-19 pandemic has highlighted the need for healthcare organizations to ensure the well-being of healthcare workers. Indeed, more stressful working hours, the fear of being infected and the need to ensure immediate decision-making have significantly increased the risk of burnout, depression, anxiety and insomnia. In the USA and Europe, a series of regulations have been issued to preserve the health of workers, specific to the workload linked to the various tasks and in the literature work-related stress indices have been evaluated in the healthcare sector, linked to muscle disorders skeletal injuries due to patient handling, for nurses and personal care/assistance workers. However, biomechanical overload and the risk of damage to the musculoskeletal system are only one aspect linked to the health of the worker: the dimension of work stress has a significant role in the general well-being of the worker during his activities and a methodology for the objective assessment of mental and physical workload in work environments.In this study we propose the use of a wearable system (WWS by Smartex) compatible with work activity, to monitor and extract significant information on the workload, due to the physical demand and the physiological response to stress, on a sample of physiotherapists. The system consists of a t-shirt for the continuous detection of a cluster of physiological parameters, that can be stored and processed during work. The system detects an ECG lead via integrated textile electrodes, the respiratory signal through the measurement of thoracic movement, posture, and physical activity recognition, via an Inertial and Magnetic Measurement Unit (IMMU), integrated into the RUSA device, a portable data logger dedicated to the acquisition, processing, storage and/or transmission of data.The RUSA is connected to the garment through a simple plug and can be easily unplugged when necessary. The T-shirt is absolutely similar to a common underwear. The base yarn is composed by antibacterial materials to guarantee a safe and prolonged use. The sensors are made of fibers that are directly woven during the production process to be fully integrated in the garment without discontinuity. The shirts come in male and female version and in several sizes to fit the largest number of users. The data acquired by the RUSA are processed on board to extract the following parameters: Hearth Rate (HR), HR Variability, RR interval, signal quality, Breathing rate, activity classification, activity intensity. The RUSA can save data on a Flash Memory (microSD), transmit data via Bluetooth® 2.1), save and transmit them simultaneously, without losing information in case of interruption of wireless transmission.A pilot study has been performed on 11 physiotherapists, engaged in XX sessions. During the study, the cluster of physiological data have been combined with a set of meta-data related to the work session such as the type of intervention (i.e. neurological rehabilitation, orthopaedic rehabilitation, etc), the level of physical impairment of the patient (according to modified Rankin score and Communicative disability scale), the working place etc.). As well as to the results of NASA questionnaire that has been administrated after each acquisition section to the physiotherapists. Preliminary results on the stress level will be presented, in parallel to evaluate the use of the IMMU platform for the overload of the musculoskeletal system, research on the posture evaluation in the rehabilitation workplace has been performed. The accuracy of a single IMMU to retrieve trunk angles was assessed by comparison with stereophotogrammetry. The results revealed that the IMMU is adequately effective in determining sagittal angles but has limitations in assessing lateral and transverse angles in a natural and uncontrolled environment.

As part of the effort to achieve an economical development of offshore fields, focus is directed towards reducing construction cost while ensuring that the quality of construction details is maintained. This construction quality is particularly important for deepwater developments because of the increased demand for higher structural integrity to minimize in-service inspection, maintenance, and repairs. High structural integrity requires that particular attention is given to improved welding details. Achieving high integrity, while maintaining adequate control on cost, requires a thorough evaluation of the constructability factors that have major influence on a project CAPEX. These factors include project organization, contracting plans, materials and welding specifications, fabrication schemes and erection and load-out procedures. While significant benefits may be achieved through knowledge base transfer and lessons learned, these factors are typically design specific and can vary on a project by project basis. I this paper, constructability parameters will be discussed along with yard selection criteria and impact of design requirements on construction cost.

Abstract Different applications of fracture bridging and diversion are used regularly in carbonate acid fracturing without an in-depth understanding of the physical phenomena that dominate the processes involved in the bridging and diversion process. The extension of modeling capabilities in conjunction with yard-scale and field-scale experiences will increase our understanding of these processes. A robust multimodal diversion pill and polylactic acid fiber-laden viscous acid were utilized for near-wellbore and far-field bridging, respectively. Numerous field treatments demonstrated the uncertainty of achieving effective diversion. An existing multiphysics model was extended to develop functionalities to model diversions at different scale. Extensive laboratory testing was conducted to understand the scale of bridging and diversion mechanisms. Finally, a bridging yard test was designed, and field case studies were used to integrate all the branches. Field cases showed a diversion pressure up to 4,000 psi depending on perforation strategy, pill volume, and pill seating rate. Correlations showed the interdependence of multiple parameters in diversion processes. The field studies motivated modeling capabilities to simulate the critical diversion processes at high resolution and quality. The model simulates diverting agents that reduce leakoff in the fracture area and their effects on fracture geometry. The approach considers the acid reaction kinetics coupled with geomechanics and fluid transport. Different diverting agent concentrations required for bridging can be modeled effectively. A yard test was designed to confirm the integrity of the pill material through completion valves (minimum inside diameter 9.5 mm) and analyzed with high-resolution imaging. All the theoretical, mathematical, and numerical findings from modeling were integrated with laboratory- and yard-scale experimentation results to develop and validate near-wellbore and far-field diversion modeling. Analytical correlations were formulated from injection rate, particulate material concentration, pill volumes, fracture width, etc., to incorporate and validate the model. This study enhances understanding of the different diversion mechanisms from high-fidelity theoretical modeling approach integrated with a practical experimental view at laboratory and field scale. Current comprehensive research has significant potential to make the modeling approach a reliable method to develop tight carbonate formations around the globe.

Abstract: This article presents a modern, e-learning method designed for the study of the draw frame for processing cotton fibers, blends of cotton and chemical fibers or chemical fibers cotton types. It exposes a new teaching and learning approach of the laboratory for subject Processes and Machines in Cotton Spinning Mill comprised in the academic curricula of the 3rd year students, specialization Technology and Design Textile Products and subject Processes in Spinning Mill comprised in the academic curricula of the 2nd year students, specialization Economic Industrial Engineering. The draw frame is placed after card machine or after combing preparation system for combed yarns. The role of the draw frames is to increase the uniformity of the bands through the doubling effect of the bands, when a doubling of 6 or 8 is used and to increase the quality of the bands by straightening the fibers. The work is accomplished in Power Point aiming to capture the attention of the students. Besides, the transition from chapter to chapter or to additional relevant aspects within a chapter is carried out by means of hyperlinks. The kinematic and technological schemes developed on Autocad serve to calculus, kinematic and technological, and facilitate a better understanding of the functioning of the machine, part of the machine or different mechanisms. Supplementary, several images, audio and video files support the learning and understanding process. The video material derive from personal records or from processing available movies in the public space, www.youtube.com, using Adobe Premiere Pro CS6 software. For each kinematic or technological parameter to be calculated, the respective kinematic chains are identified by changing the properties of the respective entities (kind, thickness or color of gears). The paper can be accessed from the official website of the university, http://www.uav.ro/, by accessing the platform on https://core.uav.ro/ containing all the bibliographic materials uploaded for university students are. The access requires a username and password, both for teachers who publish information and for students as users.

Abstract The design of fracture diversion in tight carbonates has been a challenging problem. Recently, a conceptual and theoretical workflow was presented using a β diversion design parameter that uses system volumetric calculations based on high-fidelity modeling and mathematical approximations of the etched system. A robust field validation of that approach and near-wellbore diversion modeling was conducted to extend the application. Extensive laboratory and yard-scale testing data were utilized to realize the diversion processes. Fracture and perforation modeling coupled with fracture diagnostics was used to define system volumetrics, defined as the volume where the fluid needs to be diverted away from. Multimodal particulate pills were used based on a careful review of the size distribution and physical properties. Bottomhole reactions and post-fracturing production for multiple wells and 100 particulate pills were studied to see the effect of the β factor on diversion and production performance. A multiphysics near-wellbore diversion model was used for the first time to simulate the pill effect. Representative wells were selected for the validation study; these included vertical and horizontal wells and varying perforation cluster design, stages, and acid treatments. A complex problem was solved with reaction modeling coupled with near-wellbore diversion for the first time based on given lithology and pumped volumes to match the treatment and diversion differential pressures. Final active fractures and stimulation efficiency were computed through etched geometry. The results showed a range of etched fracture length from 86 to 109 ft and width of 0.05 to 0.08 in. A similar approach was used for perforation system analysis. Diversion pills from 2 to 15 per well were investigated with a 5- to 12-bbl particulate diversion pill range. Finally, the β factor was calculated for each case based on the diversion material and system volumetric ratio. The parameter was plotted against the average diversion pressure achieved and showed an R2 of 0.87. Based on the comprehensive theoretical, numerical modeling, and field-coupled findings, a β factor of 0.8 to 1.0 is recommended for optimum diversion and production performance. For multiple cases, stimulation efficiency and production performance have been enhanced up to 200%. From the field results, it is evident that the design of near-wellbore diversion needs to be strategic. The unique diversion framework provides the basis for such a well- and reservoir-specific strategy. Proper and scientific use of diversion material and modeling can lead to advances in overall project management by optimizing the cost–efficiency–quality project triangle. Digital advancements with digitized cores, fluid systems, and advanced modeling have significant potential for the engineered development of tight carbonates.