Tapered Bore

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M.s.j. Hashmi - One of the best experts on this subject based on the ideXlab platform.

  • Plastohydrodynamic drawing and coating of stainless steel wire using a Tapered Bore die of no metal to metal contact
    2018
    Co-Authors: S. Hasan, O. Basmage, J. T. Stokes, M.s.j. Hashmi
    Abstract:

    A review of wire coating studies using plasto-hydrodynamic pressure shows that most of the works were carried out by conducting experiments simultaneously with simulation analysis based upon Bernoulli’s principle and Euler and Navier-Stokes (N-S) equations. These characteristics relate to the domain of Computational Fluid Dynamics (CFD) which is an interdisciplinary topic (Fluid Mechanics, Numerical Analysis of Fluid flow and Computer Science). This research investigates two aspects: (i) simulation work and (ii) experimentation. A mathematical model was developed to investigate the flow pattern of the molten polymer and pressure distribution within the wire-drawing dies, assessment of polymer coating thickness on the coated wires and speed of coating on the wires at the outlet of the drawing dies, without deploying any pressurizing pump. In addition to a physical model which was developed within ANSYS™ environment through the simulation design of ANSYS™ Workbench.The design was customized to simulate the process of wire-coating on the fine stainless-steel wires using drawing dies having different Bore geometries such as: stepped parallel Bore, Tapered Bore and combined parallel and Tapered Bore. The convergence of the designed CFD model and numerical and physical solution parameters for simulation were dynamically monitored for the viscous flow of the polypropylene (PP) polymer. Simulation results were validated against experimental results and used to predict the ideal Bore shape to produce a thin coating on stainless wires with different diameter. Simulation studies confirmed that a specific speed should be attained by the stainless-steel wires while passing through the drawing dies. It has been observed that all the speed values within specific speed range did not produce a coating thickness having the desired coating characteristic features. Therefore, some optimization of the experimental set up through design of experiments (Stat-Ease) was applied to validate the results. Further rapid solidification of the viscous coating on the wires was targeted so that the coated wires do not stick to the winding spool after the coating process.

  • Plasto–hydrodynamic pressure distribution in an exponentially converging coating unit
    International Journal of Materials & Product Technology, 2014
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    Hydrodynamic coating is a process, whereby a metal continuum is coated by passing it through a hydrodynamic pressure unit filled with polymer melt. The geometry of the pressure unit is always converging. Theoretical analysis have been found in literature to predict the pressure distribution in stepped parallel Bore, Tapered Bore or combined parallel and Tapered Bore units. In this paper a mathematical model has been developed for the pressure distribution within a exponentially converging hydrodynamic coating unit. Theoretical results are obtained for different continuum speeds in terms of the changes in viscosity, shear stress and pressure distributions within the unit.

  • Polymer Flow Analysis in a Tapered Bore Coating Unit: Combination of Shear and Extensional Flow
    Polymer-plastics Technology and Engineering, 2008
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    For the last few years, hydrodynamic wire coating process has been investigated by a number of researchers. In previous works, non-Newtonian analyses for wire coating were carried out using a stepped parallel or Tapered Bore pressure unit. In those analyses, the fluid flow was assumed to be pure shear and the Rabinowitch equation was used to simulate the flow. In this article, analysis for wire coating using a Tapered or conical Bore pressure unit has been developed considering the polymer melt as power law fluid and the fluid flow as a combination of both shear and extensional. Theoretical results are obtained for different wire speeds in terms of the changes in shear and extensional viscosity, shear and extensional stress, and pressure distribution within the pressure unit. Theoretical hydrodynamic pressure and drawing force results have been compared with the experimental results.

  • Wire drawing and coating using a combined geometry hydrodynamic unit: Theory and experiment
    Journal of Materials Processing Technology, 2006
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    Abstract In conventional drawing, the diameter of the wire is reduced by pulling it through a reduction die. By plasto-hydrodynamic technique, the wire diameter can be reduced by a limited amount without using any conventional reduction die. In this process, the wire is pulled through a tubular orifice of certain Bore which is filled with a viscous fluid (polymer). The smallest Bore size of the orifice is always greater than the diameter of the undeformed wire and hence it is possible to avoid metal-to-metal contact. During the past few years, plasto-hydrodynamic wire drawing has been investigated by different researchers using either stepped parallel or Tapered Bore pressure unit. In this paper, wire drawing and coating using a combined parallel and Tapered Bore hydrodynamic unit has been modelled considering that the polymer is a non-Newtonian fluid and results are obtained for different wire speeds in terms of the changes in viscosity, shear stress, percentage reduction in area, pressure distribution and coating thickness.

  • Hydrodynamic wire coating using a Tapered Bore pressure unit
    Journal of Materials Processing Technology, 2006
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    Abstract In the conventional process of wire coating, the wire is either dipped in the coating material or is coextruded along with the coating material. Apart from dipping or coextrusion methods, there is another innovative method called hydrodynamic coating in which the polymer melt is used as a pressure medium in a pressure unit. The wire size is less than the smallest Bore of the pressure unit. The wire coating thickness and quality depend on the wire speed, polymer viscosity, polymer melt temperature and the gap between the wire and exit end of the die. In this paper, results of experimental investigation are presented by comparing the coating quality on galvanized mild steel wire using molten Nylon 6 is used as the coating material in a Tapered pressure unit at different temperatures and backpressures. The coating thickness and quality are also discussed for different wire speeds of up to 12 m/s.

S. Akter - One of the best experts on this subject based on the ideXlab platform.

  • Plasto–hydrodynamic pressure distribution in an exponentially converging coating unit
    International Journal of Materials & Product Technology, 2014
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    Hydrodynamic coating is a process, whereby a metal continuum is coated by passing it through a hydrodynamic pressure unit filled with polymer melt. The geometry of the pressure unit is always converging. Theoretical analysis have been found in literature to predict the pressure distribution in stepped parallel Bore, Tapered Bore or combined parallel and Tapered Bore units. In this paper a mathematical model has been developed for the pressure distribution within a exponentially converging hydrodynamic coating unit. Theoretical results are obtained for different continuum speeds in terms of the changes in viscosity, shear stress and pressure distributions within the unit.

  • Polymer Flow Analysis in a Tapered Bore Coating Unit: Combination of Shear and Extensional Flow
    Polymer-plastics Technology and Engineering, 2008
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    For the last few years, hydrodynamic wire coating process has been investigated by a number of researchers. In previous works, non-Newtonian analyses for wire coating were carried out using a stepped parallel or Tapered Bore pressure unit. In those analyses, the fluid flow was assumed to be pure shear and the Rabinowitch equation was used to simulate the flow. In this article, analysis for wire coating using a Tapered or conical Bore pressure unit has been developed considering the polymer melt as power law fluid and the fluid flow as a combination of both shear and extensional. Theoretical results are obtained for different wire speeds in terms of the changes in shear and extensional viscosity, shear and extensional stress, and pressure distribution within the pressure unit. Theoretical hydrodynamic pressure and drawing force results have been compared with the experimental results.

  • Wire drawing and coating using a combined geometry hydrodynamic unit: Theory and experiment
    Journal of Materials Processing Technology, 2006
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    Abstract In conventional drawing, the diameter of the wire is reduced by pulling it through a reduction die. By plasto-hydrodynamic technique, the wire diameter can be reduced by a limited amount without using any conventional reduction die. In this process, the wire is pulled through a tubular orifice of certain Bore which is filled with a viscous fluid (polymer). The smallest Bore size of the orifice is always greater than the diameter of the undeformed wire and hence it is possible to avoid metal-to-metal contact. During the past few years, plasto-hydrodynamic wire drawing has been investigated by different researchers using either stepped parallel or Tapered Bore pressure unit. In this paper, wire drawing and coating using a combined parallel and Tapered Bore hydrodynamic unit has been modelled considering that the polymer is a non-Newtonian fluid and results are obtained for different wire speeds in terms of the changes in viscosity, shear stress, percentage reduction in area, pressure distribution and coating thickness.

  • Hydrodynamic wire coating using a Tapered Bore pressure unit
    Journal of Materials Processing Technology, 2006
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    Abstract In the conventional process of wire coating, the wire is either dipped in the coating material or is coextruded along with the coating material. Apart from dipping or coextrusion methods, there is another innovative method called hydrodynamic coating in which the polymer melt is used as a pressure medium in a pressure unit. The wire size is less than the smallest Bore of the pressure unit. The wire coating thickness and quality depend on the wire speed, polymer viscosity, polymer melt temperature and the gap between the wire and exit end of the die. In this paper, results of experimental investigation are presented by comparing the coating quality on galvanized mild steel wire using molten Nylon 6 is used as the coating material in a Tapered pressure unit at different temperatures and backpressures. The coating thickness and quality are also discussed for different wire speeds of up to 12 m/s.

  • Experimental results of high speed wire coating using a combined hydrodynamic unit
    Journal of Materials Processing Technology, 1999
    Co-Authors: S. Akter, M.s.j. Hashmi
    Abstract:

    Abstract In the conventional process of wire coating, the wire is either dipped in the coating material or is coextruded along with the coating material. Apart from dipping or coextrusion methods there is another innovative method called hydrodynamic coating. Different experimental works on this new process have been found in literature. In all of these works, the wire speed in the process was rather low. Coating at this speed does not promise much for industrial scale production. In this paper the results of experimental investigation using a combined parallel and Tapered Bore unit have been presented comparing the coating quality on galvanized mild steel wire when molten Nylon 6 was used as the coating material at different temperatures and back pressures. The coating thickness and quality and drawing force due to the pulling action of the wire through the pressure media have also been discussed for different wire speeds of up to 12 m s−1.

J N Kapur - One of the best experts on this subject based on the ideXlab platform.

J. Grigonienė - One of the best experts on this subject based on the ideXlab platform.

  • MODELING AND DIAGNOSTICS OF THE GEAR POWER TRANSMISSIONS
    Mechanika, 2011
    Co-Authors: V. Barzdaitis, J. Grigonienė, P. Mažeika, R. Didžiokas, V. Kartašovas
    Abstract:

    This article presents experimental and theoretical research data based on mechanical vibrations of low speed rotor system (up to 40 rpm) with a gear transmission and double row spherical roller bearings with Tapered Bore. The rotor system experimental and theoretical modeling research analysis results confirm effective technical condi-tions monitoring and failures diagnostics method of low speed rotor system with antifriction bearings. The model-ing and simulation acquired results generate determina-tions of residual operation time and service of gear trans-missions and roller bearings. Authors presented a method of low rotation speed rotor vibration severity evaluation with validation data acquired by the experimental data of continuous long term running machine in situ. http://dx.doi.org/10.5755/j01.mech.17.1.206

  • Modeling and Simulation of the Gear Power Transmissions in the Diagnostics Medium
    2011
    Co-Authors: V. Barzdaitis, J. Grigonienė
    Abstract:

    This article presents experimental and theoretical research on mechanical vibrations of low speed rotor (up to 40 rpm) with a gear transmission and double row spherical roller bearings with Tapered Bore. The research results confirm effective technical conditions monitoring and failures diagnostics method of low speed rotor with antifriction bearings. The acquired results generate determinations of residual operation time and service rotor system. Authors presented a method of low rotation speed rotor vibration severity evaluation with validation by the experimental data.

Zhou Xiang-yang - One of the best experts on this subject based on the ideXlab platform.