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The problems of the uneven strip shape and low efficiency of tea de-enzyming and carding machines in the working process were addressed by analyzing the trajectory of tea particles and establishing a force model diagram of tea particles in the pot slot. The three-dimensional geometric model of the tea de-enzyming and carding machine was drawn using UG software, and the simulation model of tea particles was established using EDEM software. The work efficiency of the tea de-enzyming and carding machine was improved, and the rate of broken tea was reduced using the EDEM software to simulate the movement of tea particles in the pot slot under different heights of the convex bar, pot slot angle of inclination, and number of slots. The average velocity and interaction force curve of tea particles were obtained. The influence of the number of slots, the inclination angle of the slot, and the height of the convex bar on the effect of tea into strips were verified using a scheme design based on the quadratic regression orthogonal combination rotation test, and experimental research based on three factors and three levels was carried out. Design-Expert 11 software (Stat-Ease, Minneapolis, MN, USA) was used to optimize the response surface and analyze the regression model of the relevant test data. The 6CSL-800 tea de-enzyming (Anji Yuanfeng Tea Machinery Co., Ltd., Huzhou, China) and carding machine (Anji Yuanfeng Tea Machinery Co., Ltd., Huzhou, China) was used as the verification test prototype, six sets of verification tests were carried out, and the test results showed that the maximum value of the strip rate index and the minimum value of the broken tea rate index were obtained. The order of the indicators affecting the bar-type rate and broken tea rate of the de-enzyming and carding machine from high to low is as follows: the height of the convex bar, the inclination angle of the slot body, and the number of slots bodies. When the height of the convex bar was 10 mm, the inclination angle of the slot was 90°, the number of slots was 12, the bar-type rate was 89.45%, and the broken tea rate was 1.63%. The prediction results of the regression model of the bar-type rate and broken tea rate of the tea de-enzyming and carding machine were verified by employing six sets of control tests with the 6CSL-800 tea de-enzyming and carding machine as the validation test prototype. The actual values of the bar-type rate obtained from the six sets of control tests were 88.19%, 90.37%, and 87.33% (1,2,3 group), and the actual values of the broken tea rate were 1.66%, 1.69%, and 1.61% (4,5,6 group), with average values of 88.63% and 1.65%. The control test was basically consistent with the results of parameter optimization. The processed finished tea has good quality, which can provide theoretical reference for the optimization and design of tea de-enzyming and carding machines and similar tea machines in the future.

The following paper presents the solution to the problem of searching the best shape – structural form of the bottoms and optimal dimensions of the main cylinder of the carding machine with consideration to the criterion of minimal deflection amplitude of its shell. The Finite Element Method has been applied for searching the optimal solution. As a result of the performed analyses, reduction of deflection amplitude at approximately 77% has been obtained. The determined optimal structural form and dimensions of the cylinder enable application of a new textile technology – microfibre carding as well as improvement in the quality of traditional carding technology of woolen and wool-like fibres performed on roller carding machine. The final stage of the work has been to determine the influence of manufacturing tolerances of the cylinder and metallic card wire on the amplitude of the main cylinder deflection.

The current roller carding machine control methods lack in the theoretical basis of using an auto-leveler, and are limited to the control of the cotton web layer thickness or the input amount of fibers. When the input amount changes, the output response is relatively slow, thus resulting in considerable impact on fiber web quality. Therefore, this study first established the theoretical modeling, and validated the dynamic mathematical model of the roller carding machine. This study used the sliding mode control in the design of the controller to control uniformity of the output fiber web of the roller carding machine. The sliding mode control used in this study was to allow the system to move in the dynamic process according to the pre-determined sliding mode trajectory, and then use the preset approximation conditions and switching conditions as the control law to navigate the system, in order to achieve the control objectives. Under the sliding mode control, with robust performance to suppress external disturbances and appropriate design of the sliding surface and boundary layer, dynamic model analysis and control adjustment for the system can be implemented to achieve the control objectives and uniform fiber web output. The experimental results confirmed that sliding mode control can effectively control fiber web uniformity of the roller carding machine.

It is important to detect and classify foreign fibers in cotton, especially white and transparent foreign fibers, to produce subsequent yarn and textile quality. There are some problems in the actual cotton foreign fiber removing process, such as some foreign fibers missing inspection, low recognition accuracy of small foreign fibers, and low detection speed. A polarization imaging device of cotton foreign fiber was constructed based on the difference in optical properties and polarization characteristics between cotton fibers. An object detection and classification algorithm based on an improved YOLOv5 was proposed to achieve small foreign fiber recognition and classification. The methods were as follows: (1) The lightweight network Shufflenetv2 with the Hard-Swish activation function was used as the backbone feature extraction network to improve the detection speed and reduce the model volume. (2) The PANet network connection of YOLOv5 was modified to obtain a fine-grained feature map to improve the detection accuracy for small targets. (3) A CA attention module was added to the YOLOv5 network to increase the weight of the useful features while suppressing the weight of invalid features to improve the detection accuracy of foreign fiber targets. Moreover, we conducted ablation experiments on the improved strategy. The model volume, mAP@0.5, mAP@0.5:0.95, and FPS of the improved YOLOv5 were up to 0.75 MB, 96.9%, 59.9%, and 385 f/s, respectively, compared to YOLOv5, and the improved YOLOv5 increased by 1.03%, 7.13%, and 126.47%, respectively, which proves that the method can be applied to the vision system of an actual production line for cotton foreign fiber detection.

This study aimed to develop a dynamic model of a roller carding machine. The roller carding machine used in this study comprised one set each of feed conveyors, feed rollers, licker-in rollers, clothing rollers, a set consisting of a cylinder and doffer and two sets of carding rollers/stripping rollers. In order to establish a dynamic mathematical model of a roller carding machine, this study derived the transfer rate and collecting power of cotton web from the mode of movement, relative velocity, clothing tooth angle and friction force of the main rollers of the system. The transfer delay time of the cotton web was deduced from the clearance among working rollers, corresponding angle of roller center, and angular velocity. Finally, the correctness of the dynamic mathematical model of the roller carding machine derived in this study has been proved from the experiment.

The article presents the results of calculating the average residence time of the fiber in the flat set of the main carding zone for carding machines TS-03 (Trutzschler) and C60 (Rieter). The fiber carding degree in the “drum-flat” zone was studied. The carding degree by the teeth of the main drum of free fibers held by the needles of the flats and the carding degree by the needles of the flats of free fibers held by the teeth of the main drum were determined. The total carding degree in the “drum-flat” zone of the carding machine was calculated.

This study investigates the impact of carding and blending recycled carbon fibers (rCF) with crimped thermoplastic polypropylene (PP) fibers on the mechanical properties of rCF, using a Weibull statistical approach. Tensile properties of rCF were evaluated before and after carding with varying rCF/PP blend ratios (100/0%, 85/15%, 70/30%, and 50/50%). A comparison between the two-parameter and three-parameter Weibull models showed that the two-parameter model provided a better fit for rCF properties before carding. The results show that adding crimped PP fibers during carding helps to decrease the stress-at-break disparity and move their distribution to higher values. Furthermore, a slight increase in tensile modulus was observed in carded rCF, with higher PP ratios associated with smaller scatter modulus distributions. Elongation at break remained consistent, with the Weibull modulus increasing slightly with carding and the inclusion of PP fibers, indicating improved consistency. Overall, carding rCF with PP fibers helped in the mechanical property uniformity of the resulting carded webs without compromising tensile performance. This work shows the potential of the carding process with or without thermoplastic fibers to efficiently realign and give continuity to discontinuous recycled carbon fibers.

This study investigates the mechanical properties of nonwoven hybrid composites made from recycled cotton/polyethylene terephthalate (PET) with various fiber weight percentages (100/0, 0/100, 75/25, 60/40, 50/70, 60/40, and 25/75). The multilayered nonwoven carded webs are manufactured by the carding machine, while the manual lay‐up technique is used to fabricate nonwoven‐reinforced composites. Their tensile, flexural, and impact properties and microstructure are then examined. It is found that the tensile modulus and strength increase with the increase in cotton, while the impact strength improves with the increase in PET. The composite of 75% cotton/25% PET offers 92.13% and 67.87% higher tensile modulus and strength than the composite of 25% cotton/75% PET; however, the composite of 25% cotton/75% PET shows 83.09% and 36.22% higher flexural modulus and strength, and 187% more impact strength, respectively, than the composite of 75% cotton/25% PET. The outcome of this study indicates that nonwoven composites with higher contents of recycled cotton can potentially be applied in building and construction sectors where substantial tensile strength is necessary, while composites with comparatively higher contents of recycled PET may be used for various potential applications (e.g., helmets, surfboards, and automotive interiors) where significant flexural and impact strengths are required. The mechanical properties of recycled cotton/polyethylene terephthalate (PET) nonwoven composites with different fiber weight ratios are examined. Cotton fiber enhances tensile properties, whereas PET improves impact strength. Composites with more cotton may be used in construction for their greater tensile strength, while those with more PET can be used in automobile components and sports goods for their high flexural and impact strengths.

Since the Industrial Revolution, human societies have experienced high and sustained rates of economic growth. Recent explanations of this sudden and massive change in economic history have held that modern growth results from an acceleration of innovation. But it is unclear why the rate of innovation drastically accelerated in England in the eighteenth century. An important factor might be the alteration of individual preferences with regard to innovation resulting from the unprecedented living standards of the English during that period, for two reasons. First, recent developments in economic history challenge the standard Malthusian view according to which living standards were stagnant until the Industrial Revolution. Pre-industrial England enjoyed a level of affluence that was unprecedented in history. Second, behavioral sciences have demonstrated that the human brain is designed to respond adaptively to variations in resources in the local environment. In particular, Life History Theory, a branch of evolutionary biology, suggests that a more favorable environment (high resources, low mortality) should trigger the expression of future-oriented preferences. In this paper, I argue that some of these psychological traits – a lower level of time discounting, a higher level of optimism, decreased materialistic orientation, and a higher level of trust in others – are likely to increase the rate of innovation. I review the evidence regarding the impact of affluence on preferences in contemporary as well as past populations, and conclude that the impact of affluence on neurocognitive systems may partly explain the modern acceleration of technological innovations and the associated economic growth.

The growing need for high-performance stretchable fabrics led scientists to innovate a new spinning technique, especially for manufacturing cotton/spandex core-spun yarns. This type of yarn is spun by using spandex monofilament or multifilament as a core, which is surrounded by a sheath of staple cotton fibers. The key covering process parameters include spindle speed, delivery roller speed, spandex drafting ratio, spandex linear density, and tension level, which simultaneously influence the core-spun yarn characteristics such as tensile properties, hairiness index, imperfection index, and fabric aesthetic and performance properties. Fine-tuning these multiple covering parameters achieves optimal performance of these types of yarns. This paper aimed at employing multi-objective optimization for the covering parameters of cotton/spandex composite yarn to maximize the yarn tensile properties and minimize both hairiness and imperfection indices using the robust Taguchi technique in conjunction with the grey relational analysis. A full factorial design composed of three factors, namely spandex monofilament drafting ratio, linear density, and core-spun yarn twist multiplier, with five, four, and two levels, was conducted. Average values of the grey relational grades of all combinations were estimated, and its highest value refers to the optimal combinations of the controllable factors, which yield the best performance of cotton/spandex core-spun yarn. This study revealed that core-spun yarn with a 4.2 twist multiplier, a 44 dtex linear density of spandex monofilament, and a 4.4 drafting ratio of spandex yielded the optimal yarn performance characteristics. This study provides a methodological breakthrough with beneficial ramifications for the textile industry seeking a multi-objective optimization of core-spun yarn manufacturing parameters.