Spinning Tests Research Articles

Microstructure evolution and strengthening mechanisms of electron beam welded 2219 aluminum alloy plate after hot spinning and heat treatment

To investigate the feasibility of spinning the welded aluminum alloys, hot spinning tests were conducted on the electron beam welded (EBWed) 2219 aluminum alloy thick plates at 400 °C and successfully obtained a 2.8 mm curved welded-spun plate with a total thickness reduction of 72 %. The abnormal grain growth (AGG) phenomenon of the base material during hot spinning could be observed due to the reduced pinning effect of the θ-Al2Cu phases and static recrystallization, while the fusion zone exhibited homogeneous recrystallized microstructure. After hot spinning, the yield strength of the base material increased from 89.3 MPa to 133.6 MPa and the yield strength of the joint increased from 93.1 MPa to 134.7 MPa. To further optimize the microstructure and improve the mechanical properties of the spun alloy, the subsequent solid solution and aging treatment were conducted. Most of the coarse θ particles dissolved into the matrix and a large quantity of needle-like θ′ precipitates were generated. The yield strengths of the base material and the joint increased to 213.1 MPa and 216.4 MPa, respectively, which was mainly attributed to the precipitation strengthening of the θ′ precipitates. The comparison between the calculated yield stress and the experimental results showed that the contributions of different strengthening mechanisms in strengths were reliable.

The effect of inorganic antimicrobial agents on PET filament properties

In this study, a polybutylene terephthalate (PBT) antimicrobial masterbatch containing silver, zinc, and copper antimicrobial agents was added to polyethylene terephthalate (PET) and spun into an antimicrobial partially oriented yarn which was then texturized into a draw-textured yarn (DTY). Filtration pressure rise and spinning tests indicated that the silver antimicrobial masterbatch had the best long-term spinnability. In addition, the strength and elongation of the antimicrobial DTY were reported to match practical standards, indicating that PET containing a silver antimicrobial agent can contribute to a smooth spinning process. In an antibacterial test of gram-negative and gram-positive bacteria before and after finishing, only the silver fabric maintained over 99.99% antibacterial effectiveness. Thereafter, the silver textile was tested for strains of influenza A virus H1N1 and H3N2 to evaluate its antiviral activity before and after dyeing; the textile containing 2% silver antimicrobial agent exhibited optimal antiviral effectiveness. In conclusion, the silver-containing fabrics exhibited long-lasting antibacterial and antiviral effects.

Spinning process optimization and microstructure of stainless-steel welded pipe

Defects, such as cracks, typically occur in the spinning process of ternary catalyst shells. This study investigates the optimization of spinning process parameters to prevent such defects. In this regard, an orthogonal simulation was performed using a finite element model of the spinning process of a ternary catalyst shell. Moreover, spinning tests using a 439 stainless steel welded pipe were conducted to verify the simulation results. Thus, the microstructure, hardness, and quality of formed parts are analyzed. The simulation and test results showed that when the spinning temperature is 1000 °C, the roller fillet radius, roller speed, and feed ratio are 5 mm, 40 r s−1, and 1.2 mm r−1, respectively. In addition, the error rates of the forming thickness, port diameter, and roundness error are 1.37%, 1.25%, and 4.8%, respectively. These results verified the accuracy of the simulation. Furthermore, no defects were generated during spinning, and the spinning quality was high. The feed ratio was the main factor affecting the roundness error, followed by the roller speed. As deformation increased, hardness increased, and the crystal size decreased. The results of this study can provide crucial theoretical guidance for practical spinning applications.

Statistical Analysis and Optimisation of Data for the Design and Evaluation of the Shear Spinning Process.

This work proposes a research method that is a scheme that can be universally applied in problems based on the selection of optimal parameters for metal forming processes. For this purpose, statistical data optimisation methods were used. The research was based on the analysis of the shear spinning tests performed in industrial conditions. The process of shear spinning was conducted on the components made of Inconel 625 nickel superalloy. It was necessary to select the appropriate experimental plan, which, by minimising the number of trials, allowed one to draw conclusions on the influence of process parameters on the final quality of the product and was the starting point for their optimisation. The orthogonal design is the only design for three factors at two levels, providing non-trivial and statistically significant information on the main effects and interactions for the four samples. The samples were analysed for shape and dimensions using an Atos Core 200 3D scanner. Three-dimensional scanning data allowed the influence of the technological parameters of the process on quality indicators, and thus on the subsequent optimisation of the process, to be determined. The methods used proved to be effective in the design, evaluation and verification of the process.

EFFICIENT MULTI-VIEW 3D TRACKING OF ARBITRARY ROCK FRAGMENTS UPON IMPACT

Abstract. This paper presents a new methodology to accurately obtain 3D rotational velocities of blocks and fragments. Four high speed cameras are used to capture the scene. An additional two tilted mirrors are used to multiply the number of views. Hence, a total of six different viewing perspectives can be used to track translational and rotational velocities in 3D. The focus in the current work is on the rotational velocities, as tracking of the translation is generally straightforward. A common outline tracking algorithm based on the visual hull is adapted. The visual hull is further meshed using triangular elements to approximate the shape of the object. This 3D reconstruction is then used to track the 3D motion of the object. However, the accuracy of the results strongly depends on the accuracy of the 3D reconstruction which is mainly influenced by the number and position of the available views. In any case, the 3D reconstruction from the visual hull is only an approximation and significant errors can be introduced which influence the tracking accuracy. Hence, an in-house post-processing algorithm based on the knowledge of the real geometry of the object, which can generally be accurately determined after a test, was developed. The improved performance of this new post-processing method is shown by controlled spinning tests. Finally, results of a real example of an impact fragmentation test are discussed.

Genetic improvement in cotton fiber elongation can impact yarn quality

Fiber quality is important to the textile industry because it directly relates to processing performance, productivity and yarn quality. For marketing purposes, the fiber quality of U.S. cotton is determined by the United States Department of Agriculture (USDA) classing offices using High Volume Instrument (HVI). HVI measures fiber length, length uniformity, strength, micronaire, color, leaf and extraneous matter. Recent research shows other fiber properties not included in the USDA classification should be considered when developing new cultivars to improve spinning performance, yarn quality, and market value. Fiber properties of interest include but are not limited to fiber maturity, short fiber content, fiber elongation, and work-to-break characteristics. Breeding for higher fiber elongation is expected to result in new cultivars that can withstand processing with less fiber breakage, perform better in spinning, and produce better yarn quality. The purpose of this research was to evaluate spinning performance and yarn quality of cotton lines developed to place emphasis on fiber elongation during the breeding process.Fifteen F2 populations were followed through a series of selections to the stage of “end product” by conducting spinning tests on F5 progeny lines. Divergent selection for fiber elongation was conducted in the F2 and F3 generations with nine lines being selecting in the F4 generation for spinning. Yarn properties and fiber properties of each line were evaluated together for correlations and potential trends. Yarn quality of experimental lines was also compared to yarn quality of a commercial check cultivar. Fiber and yarn data were evaluated to determine if and clarify how fiber elongation influenced spinning performance and yarn quality.It was determined that it is possible to improve fiber elongation through breeding and that by placing an emphasis on fiber elongation improvements can be made to overall fiber and yarn quality. Results also demonstrate the potential impact of disregarding fiber elongation or selecting genotypes with low fiber elongation; there were negative effects on both fiber and yarn. There is opportunity to indirectly address multiple fiber quality objectives and improve the end-product by placing selection pressure on this specific fiber characteristic during the breeding process.

A Numerical and Experimental Study on a Pre-Twisted Ring Spinning System.

The ring spinning process is the most widely used method in the spinning industry. Nowadays, the labor cost become more and more expensive, and it is essential to improve productivity. For increasing the productivity, a modification of adding a pre-twister and holding roller on the traditional ring spinning system have been discussed in this paper. The computational fluid dynamics (CFD) are introduced to study the effects of pre-twister and spinning tests are implemented for verification. The numerical simulations show that the cavity conical degree and nozzle numbers of the pre-twister are the key parameters which affect the airflow fluctuation in the cavity, and have obvious effects on the resultant yarn twist. By contrast, the axial angle and tangential angle of the nozzle have less effect on the resultant yarn twist. When the fiber bundles pass by the front nip, they are affected by the vortex and result in a partially strengthened and wrapped structure which could be subsequently twisted less by the traveler and ring, so the productivity could be potentially increased. According to the spinning tests, an evident productivity increase by nearly 30% for medium cotton yarns can be achieved, and the yarns have an acceptable reduction in nearly all properties.

A procedure for calibrating the spinning ultrasonic wind sensors

The accuracy of wind speed and direction measurements with spinning ultrasonic wind sensors is important than ever in today’s wind industry in which, they are usually installed on the hub of the wind turbines to measure the wind speed and direction for optimized power. In this paper, extensive wind-tunnel tests have been performed to calibrate the wind speed and direction measured by a spinning single-axis ultrasonic anemometer for both static and spinning conditions. This has been carried out with static measures at various stationary angles of transducers signal path with wind direction, and with dynamic measures in which the anemometer is rotating with various rotational speeds. The velocity measured by ultrasonic anemometer in static tests is calibrated with pitot-tube data, and the interpolation of obtained calibration coefficients is used to correct the ultrasonic velocity measured in dynamic tests. It is observed that the calibrated ultrasonic wind speed measurements in dynamic tests are in a good agreement with the reference velocity. According to the results, the ultrasonic velocity measurements in both static and dynamic tests are affected by the transducers head distortions, and the shifting in acoustic pulse trajectory due to the rotational motion does not affect the anemometer measurements. The uncertainty of the calibration process for the spinning tests was found to be about 0.3%.

Mechanics analysis on the composite flywheel stacked from circular twill woven fabric rings

The filament wound composite flywheel had a deficiency of being fragile along the radial direction because there is no reinforcing phase distribution. The failure along the radial direction due to delamination may happen when the thick cylinder composite flywheel rotate at high speed. A new way to solve the low radial strength problem of the composite flywheel is to use woven fabric material. The 2D woven fabric composite in the form of a circular ring has fibers in both the circumferential and radial directions to bear the stress. This structure features the combination of the typical two-dimensional orthogonal textile fabric and the classic axial laminations, performing new characters in mechanics. Samples of composite disks with 2D woven fabric material were designed and fabricated for spinning test, and the mechanics analysis on the thin woven composite disk was carried out for the first time. With the introduction of micromechanics methods, the elastic constants of the unit cell model of periodic volume representing the whole fabric were extracted from geometrical simplification and homogenization theories. The stiffness and strength of orthogonal twill woven fabric were predicted to evaluate the failure spinning speed of the fabric composite disks. The theoretical maximum spin speed of the woven flywheel could reach 1261rps with energy density of 53Wh/kg. The tension test data on samples of twill woven fabric composite helped with the prediction of failure of disk samples. The spinning tests confirmed that the tail weakness of the stacked configuration and the stiffness degradation from defects in composite contributed greatly to the stable running of flywheel spin.

Characterization of the coagulation process: wet-spinning tool development and void fraction evaluation

Since very little research has been published on the wet-spinning process, this article is a contribution to understanding the coagulation phenomenon. In this work, the effects of spinning parameters on the evolution of the void fraction of coarse polyamide-imide monofilaments were investigated. First of all, an experimental wet-spinning device was designed in our laboratory. Robust and reliable, this prototyping tool allows a fully automated production, ensuring the reproducibility of the different spinning tests. A four-factor Design of Experiments was built to analyze the effects and combinations between the following parameters: extrusion diameter, concentration of the coagulation bath and drawing rates applied in the coagulation bath and in the air. The results derived from a statistical analysis coupled to a scanning electron microscope study showed a highly significant influence of the concentration of solvent in the coagulation bath, concerning the evolution of the void fraction of the obtained monofilaments.

Spindle Speed Optimization for Cotton Pickers

Abstract. There is concern that changes to the operating speed and size of spindles on cotton picker harvesters over the years have resulted in a general decrease in cotton fiber quality, especially spindle twists, preparation, and neps. Previous research showed that spindle speeds of 3000 and 4000 rpm had more detrimental effects on picker stalk loss, trash levels in seed cotton, and cotton fiber quality than a spindle speed of 2000 rpm. This study was conducted to check fiber quality effects between 2000 and 2800 rpm in order to further define the optimum spindle speed range. Field tests were conducted for the 2008 and 2009 crop years by the USDA, Agricultural Research Service, Southwestern Cotton Ginning Research Laboratory in Mesilla Park, New Mexico. Three cotton varieties were grown under furrow-irrigated conditions in southern New Mexico and harvested with a modified one-row cotton picker each year using a ground speed of 0.85 m s-1 (1.9 miles h-1) and spindle speeds of 2000, 2200, 2500, and 2800 rpm. The tests were replicated four times. No significant differences in stalk losses in the field were found. Significantly more trash was present in seed cotton picked with spindle speeds of 2200, 2500, and 2800 rpm than in seed cotton picked with a spindle speed of 2000 rpm. Differences in trash content were eliminated by seed cotton cleaning (same for all treatments). HVI classing data showed no significant differences among spindle speed treatments. Differences due to spindle speed for AFIS nep count, short fiber count, trash count, dust count, and seed coat nep count were non-significant at each of the four locations tested in the yarn preparation process. Results from open-end spinning tests, including opening and cleaning waste, total card waste, ends down, yarn strength, yarn elongation, neps, thick places, and thin places showed no significant differences due to spindle speed. Based on these results, the 2000 rpm spindle speed is optimal because trash in the seed cotton is reduced which reduces ginning costs; however; only minimal differences are present at spindle speeds up to 2800 rpm.

Fatigue Crack Growth in Blade Attachment of Turbine Disks: Experimental Tests and Life Prediction

Abstract To assess residual life for those component parts where low cycle fatigue (LCF) design is adopted, especially for those critical regions where high stress concentrations cause cyclic yielding of the material, it is necessary to consider the presence of potential defects and their propagation during service. In order to represent the high stress concentration at the root of blade attachments in a gas turbine and the typical elastic-shakedown conditions, a notched specimen has been designed and tested. A series of experimental tests in three regimes have been carried out with the presence of small semi-circular micronotches and crack growth rates have been measured with plastic replicas. The results have shown that the initial over-load impressed by the spinning tests is able to double the propagation lifetime. The experimental results have then been successfully analyzed with Newman's crack growth model applied to the elastic shakedown stress fields at the notch root.

The effect of melt spinning process parameters on the spinnability of polyetheretherketone

AbstractThis study has been carried out to investigate the processing parameters affecting polyetheretherketone's (PEEK) spinnability in a melt spinning process. PEEK has excellent mechanical and thermal properties and fibers made from it could be used in extreme environments. Different PEEK grades were characterized thermally and rheologically to see which one is the most suitable for fiber spinning. The spinning tests made with the most suitable grade (Victrex 151G) show that increased processing temperature, increased capillary diameter or shorter spinning path length improves spinnability. The best fibers made in optimal processing conditions (400°C temperature, 30/1 mm capillary, and 5 cm spinning path) were 18 μm in average diameter. Because of the limitations of the system used, variations in fiber thickness were noticeable and worsened the spinning stability. Scanning electron microscope photos confirmed these variations, and they were also visible in an optical microscope. The selected low‐viscosity PEEK grade provided good spinnability but gave filaments with only mediocre mechanical properties, the tensile strength being around 280 MPa. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

OPTIMIZING RING SPINNING VARIABLES AND A PROPOSED PROCEDURE TO DETERMINE THE EGYPTIAN COTTON SPINNING POTENTIAL

In this study, many approaches were examined such as spindle defects and yarn bobbin position along with successively varying spindle speed to select the optimum processing parameters for standard testing of the Egyptian cotton, and hence suggesting a spinning procedure for the CRI 96-spindle-hour spinning test. Giza 80 was used to test the spindle error and yarn bobbin position also, to study the varying spindle speed, while, Giza 80 as well as Giza 86 and Giza 70 were used to reveal the spinning limit technique. The coefficient of variation in lea count strength product (introduced between the spindles of the ring frame) was considerable, the variance was very small (1.01 %) in extreme cases and could be neglected. The lea count strength product at different positions on the bobbin spun on the ring frame between the pigtail to full bobbin was insignificant. The increase in spindle speed from 1000 to 17500 rpm did not affect single yarn strength, yarn evenness and yarn hairiness. The total imperfections are minimum at 10000 rpm of spindle, and beyond this speed the imperfections increase gradually with the increase in spindle speed. The proposed procedure of accelerated spinning technique appears promising in indicating the relative level of end breakage and optimum yarn quality parameters for different cotton varieties. A series of 96- spindle-hour spinning tests proved to be reliable in exploring practical spinning limits of any cotton to find out the finest count for a particular cotton taking in consideration ends-down and yarn quality parameters

Determination of the elongational viscosity of polymer melts by melt spinning experiments. A comparison with different experimental techniques

In this work, melt spinning experiments were tentatively used for the determination of the elongational viscosity of polymer melts at different levels of tensile strain and strain rate. The materials examined were two high-density polyethylene grades for blow moulding with similar number-average molecular mass but different polydispersity index. The data from melt spinning tests were compared with transient extensional viscosity data obtained by uniform isothermal tensile tests, performed by means of an extensional rheometer, as well as with those produced by converging flow tests (Cogswell model). The results showed that for high strain and strain rate levels, the melt spinning experiments provide elongational viscosity data quite close to the transient extensional viscosity values obtained from the tensile tests.

Developing a New Drafting System for Ring Spinning Machines

In order to raise yam quality, a new drafting system concept for ring spinning machines is developed in this study, along with an analysis of its controlling effects. To optimize the new drafting system, its structural parameters are studied and two empirical equations for yarn unevenness and nep count model its design. The equation of yam unevenness is used to find the optimum structural parameters of the new drafting system. Practical spinning tests with the optimized system prove that it can reduce unevenness, thin places, thick places, and neps in spun yarns, and that the equation for yarn unevenness can be used to satisfactorily estimate the unevenness of spun yams.

Dynamic Properties of the Rotary Ring

In the cotton spinning process, the performance and effect of a rotary type ring has been compared with those of a conventional type ring. The Rotor Spin Ring®, the rotary ring developed by our research laboratory, have been put to practical use. Further, dynamic properties of the rotary ring are analyzed theoretically.The cotton spinning tests show that in using the rotary ring the abrasion of travellers decreases and the yarn quality is evaluated in comparison with the conventional but other effects are not confirmed.A theoretical calculation has shown that the consumption of the electric power in the spinning process with the rotary ring is identical with that of the conventional, if the spinning tension of the both type of ring is equal. In practical spinning process, however, the spinning tention of the rotary ring is higher than that of a conventional ring even if travellers of the same count are used. Thus, the rotary rings increase the consumption of electric power.In conclusions the rotary ring gives little effect on the cotton spinning process.

Revolving Ring

A relatively simple but an effective mechanical device has been designed and developed which is capable of rotating the ring at any desired speed in the direction of the traveller. The comparative spinning tests on the conventional and revolving rings on the same conventional ring spinning frame have proved that the revolving ring is highly effective in reducing the end-breakages at high production rates. Besides increased production rates, the basic concept of revolving the ring has several added advantages, such as better yarn appearance, regularity and twist-distribution and longer life of the traveller.

Studies on the sowing date of cotton in the Sudan Gezira: III. The effect of sowing date on yield and quality under different fertilizer and spraying treatments

Field experiments from 1959–60 to 1963–4 showed that when blackarm resistant strains of Egyptian type cotton were sown around the beginning of August and adequately protected from fleabeetle, the resultant crop was of higher yield and considerably better average quality than that from the normal mid-to-late August sowings. Effective length, maturity ratio, standard fibre weight, bundle strength and lea-count × strength product were all improved. Sowing in early July, tested in one season only, gave rather better quality but lower yield than sowing in early August. Sowing in late August or in September depressed both yield and quality. The importance of direct climatic effects and of blackarm, fleabeetle, bollworm, other insect pests and wilt in controlling the choice of, and response to, sowing date is briefly discussed.Thanks are due to the Sudan Gezira Board for kindly supplying the results of the large-scale sowing date trials and for the grading of experimental cotton, to the Shirley Institute of Manchester for the fibre and spinning tests and to the Chief, Agricultural Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper.

Cleaning Action of Cotton Card Equipped with Metallic Card Clothing Part 1 Comparative Spinning Tests of the Cards Equipped with Metallic Card Clothing and Wire Fillet Clothing

In using metallic card clothing for cotton processing, the most important step to be taken is to reduce impurities-neps and other imperfection-in the sliver and, therefore, in the yarn. A number of comparative spinning tests has been made of two types of card: (a) MC, equipped with several tooth angle combinations of metallic card clothing on the cylinder and on the doffer; (b) FC, equipped with an ordinary wire fillet clothing. The behavior of impurities has been minutely analyzed in each case. The impurities discharged into various parts of a card have been classified into four kinds by their structures and into six classes by their sizes. It has been concluded from the tests that neps are always fewer in a sliver on MC than in a sliver on FC, because there is a smaller deposit of fibers on MC's cylinder and flats and, therefore, there is less nep formation. It has been concluded also that the other kinds of impurities in a sliver on MC can also be made fewer than in a sliver on FC if the tooth angle combination is properly adjusted. The proper adjustment is to make the tooth angle large on the cylinder and small on the doffer. This reduces the fiber density on the cylinder surface, improves the impurity-removing ability of the flats, and lessens the impurities in the sliver. These results have been confirmed again by the fact that yarns spun from an MC-processed slivers get a better rating for neps and other imperfections in an appearance test. Since there is no appreciable difference in the quality of the yarn except in the impurities, metallic clothing can be very profitably used for cotton spinning also.