• Fibers and Polymers
• /
• v.5 no.4
• /
• pp.275-279
• /
• 2004

Yarn tension is a key factor that affects the efficiency of a ring spinning system. In this paper, a specially constructed rig, which can rotate a yam at a high speed without inserting any real twist into the yarn, was used to simulate a ring spinning process. Yarn tension was measured at the guide-eye during the simulated spinning of different yarns at various balloon heights and with varying yarn length in the balloon. The effect of balloon shape, yarn hairiness and thickness, and yam rotating speed, on the measured yarn tension, was examined. The results indicate that the collapse of balloon shape from single loop to double loop, or from double loop to triple etc, lead to sudden reduction in yarn tension. Under otherwise identical conditions, a longer length of yarn in the balloon gives a lower yarn tension at the guide-eye. In addition, thicker yarns and/or more hairy yarns generate a higher tension in the yarn, due to the increased air drag acting on the thicker or more hairy yarns.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11b
• /
• pp.817-825
• /
• 2001

The natural frequencies of a flexible spinning disk misaligned with the axis of rotation are studied in an analytic manner. The effects of misalignment on the natural frequency need to be investigated, because the misalignment between the axis of symmetry and the axis of rotation cannot be avoided in the removable disks such as CD-R, CD-RW or DVD disks. Assuming that the in-plane displacements are in steady state and the out-of-plane displacement is in dynamic state, the equations of motion are derived for the misaligned spinning disk. After the exact solutions are obtained for the steady-state in-plane displacements, they are plugged into the equation for the dynamic-state out-of-plane motion. The resultant equation is a linear equation for the out-of-plane displacement, which is discretized by the Galerkin method. Based on the discretized equations, the effects of the misalignment are analyzed on the vibration characteristics of the spinning disk, i.e., the natural frequencies and the critical speed

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.10
• /
• pp.915-922
• /
• 2010

This paper presents an efficient method for determining the forced response of a spinning flexible disk-spindle system supported by fluid dynamic bearings(FDBs) in a computer hard disk drive(HDD). The spinning flexible disk-spindle system is represented by the asymmetric finite element equations of motion originating from the asymmetric dynamic coefficients of the FDBs and the gyroscopic moment of a spinning disk-spindle system. The proposed method utilizes only the right eigenvectors of the eigenvalue problem to transform the large asymmetric finite element equations of motion into a small number of coupled equations, guaranteeing the accuracy of their numerical integration. The results are then back-substituted into the equations of motion to determine the forced response. The effectiveness of the proposed method was verified by comparing it with the responses from the classical methods of mode superposition with the general eigenvalue problems, and mode superposition with modal approximation. The proposed method was shown to be effective in determining the forced response represented by the asymmetric finite element equations of motion of a spinning flexible disk-spindle system supported by FDBs.

• Geomechanics and Engineering
• /
• v.24 no.3
• /
• pp.267-280
• /
• 2021

The research presented in this paper deals with dynamic stability analysis of the graphene nanoplatelets (GPLs) reinforced composite spinning disk. The presented small-scaled structure is simulated as a disk covered by viscoelastic substrate which is two-parametric. The centrifugal and Coriolis impacts due to the spinning are taken into account. The stresses and strains would be obtained using the first-order-shear-deformable-theory (FSDT). For Poisson ratio, as well as various amounts of mass densities, the mixture rule is employed, while a modified Halpin-Tsai model is inserted for achieving the elasticity module. The structure's boundary conditions (BCs) are obtained employing GPLs reinforced composite (GPLRC) spinning disk's governing equations applying principle of Hamilton which is based on minimum energy and ultimately have been solved employing numerical approach called generalized-differential quadrature-method (GDQM). Spinning disk's dynamic properties with different boundary conditions (BCs) are explained due to the curves drawn by Matlab software. Also, the simply-supported boundary conditions is applied to edges 𝜃=𝜋/2, and 𝜃=3𝜋/2, while, cantilever, respectively, is analyzed in R=R_i, and R₀. The final results reveal that the GPLs' weight fraction, viscoelastic substrate, various GPLs' pattern, and rotational velocity have a dramatic influence on the amplitude, and vibration behavior of a GPLRC rotating cantilevered disk. As an applicable result in related industries, the spinning velocity impact on the frequency is more effective in the higher radius ratio's amounts.

• Korean Journal of Materials Research
• /
• v.34 no.7
• /
• pp.355-362
• /
• 2024

AR (alkali resistant)-glass fibers were developed to provide better alkali resistance, but there is currently no research on AR-glass fiber manufacturing. In this study, we fabricated glass fiber from AR-glass using a continuous spinning process with 40 wt% refused coal ore. To confirm the melting properties of the marble glass, raw material was put into a (platinum) Pt crucible and melted at temperatures up to 1,650 ℃ for 2 h and then annealed. To confirm the transparent clear marble glass, visible transmittance was measured and the fiber spinning condition was investigated by high temperature viscosity measurement. A change in diameter was observed according to winding speed in the range of 100 to 700 rpm. We also checked the change in diameter as a function of fiberizing temperature in the range of 1,240 to 1,340 ℃. As winding speed increased at constant temperature, fiber diameter tended to decrease. However, at fiberizing temperature at constant winding speed, fiber diameter tended to increase. The properties of the prepared spinning fibers were confirmed by optical microscope, tensile strength, modulus and alkali-resistance tests.

• Proceedings of the Korean Fiber Society Conference
• /
• 2002.04a
• /
• pp.273-276
• /
• 2002

The fiber formation of conventional melt spinning is extruded by forcing the polymer melt through a spinneret by pumping mechanism usually involving high pressure. This is followed by cooling, solidification and appropriate drawing of the fiber. The spinning process is broadly applicable to polyolefin, polyamide, polyester and indeed the whole range of fibers forming thermoplastic polymers. (omitted)

• 전기의세계
• /
• v.28 no.5
• /
• pp.49-55
• /
• 1979

During severe emergencies which result in insufficient generation to meet load, an automatic load shedding method considering the spinning and operating reserve can establish the optimum system operation. This paper presents methods and results of a study on the optimum operating scheme with spinning and operating reserve power in case of outage of large generator units to prevent frequency decay and continue stable operation. This study covers following three parts 1) Analysis of spinning reserve characteristics 2) Determination of operating reserve requirements 3) Development of the optimum load shedding programs By this study the optimum system operating method was recommended for reliable operation of power system.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2008.10a
• /
• pp.147-148
• /
• 2008

This is studied about the development of new PET yarn having the new appearance and touch effect of Polyester(PET) Yarn as using spinning and texturing technology. The spinning technology is that we use the manufacturing technology caused to the denier difference of filaments composing of yarn. And the texturing technology is that we develope texturing condition caused to spun yarn effect as using filaments producing from the spinning processing.

• Transactions of Materials Processing
• /
• v.14 no.4 s.76
• /
• pp.375-383
• /
• 2005

The shear spinning process, where the plastic deformation zone is localized in a very small portion of the workpiece, shows a promise for increasingly broader application to the production of axially symmetric parts. In this paper, the three components of the working force are calculated by a newly proposed deformation model in which the spinning process is understood as shearing deformation after uniaxial yielding by bending, and shear stress, $\tau_{rz}$, becomes k, yield limit in pure shear, in the deformation zone. The tangential force are first calculated and the feed force and the normal force are obtained by the assumption of uniform distribution of roller pressure on the contact surface. The optimum contact area is obtained by minimizing the bending energy required to get the assumed deformation of the blank. The calculated forces are compared with experimental results. A comparison shows that theoretical prediction is reasonably in good agreement with experimental results

• Journal of Korean Society for Quality Management
• /
• v.20 no.1
• /
• pp.147-157
• /
• 1992

This article describes a prototype expert system for yarn spinning process planning in textile industry. This expert system is intended as a consultant to give the technicians interactive assistance for the appropriate process planning in accordance with used materials, required count, and other factors affected yarn spinning by means of many types of machine. Also, this system has the other function that can be compared the standard values with the measured ones for quality characteristics control. VP-EXPERT-a rule-based microcomputer expert system development tool-provides the expert system components for this development. The details of knowledge organization, rule representation, inference reasoning process, and performance of this expert system are demonstrated with the practical yarn spinning operations.