Conjugate Heat Transfer in an Optical Fiber Coating Process

2005 ◽  
Author(s):  
Sang-Yeoun Yoo ◽  
Yogesh Jaluria
Keyword(s):  
Heat Transfer ◽  
Optical Fiber ◽  
Conjugate Heat Transfer ◽  
Fiber Surface ◽  
Ultra Violet ◽  
Thermal Conditions ◽  
Coating Process ◽  
Uv Curable ◽  
Fiber Coating

The optical fiber coating process in an axi-symmetric applicator and die system was simulated in this study. Various thermal conditions and process variables are investigated. Ultra-violet (UV) curable acrylates are used for the coating material, whose properties are highly dependent on temperature. Conjugate heat transfer is considered at the moving fiber surface since the fiber constantly exchanges energy with the contacting fluid. The temperature level in the applicator and die is found to increase with fiber speed, the increase being the highest in the die whose wall temperature is kept fixed. This high temperature rise is primarily due to the tremendous viscous dissipation within the fluid, especially in the die. It is important to avoid high temperatures in the fluid because the polymer starts to crosslink and degrade. The fiber temperature at the entrance was also found to be of substantial importance. This work can be used to improve the quality of the coating, particularly its uniformity, and the production rate.

Heat Transfer in Chemical Vapor Deposited Optical Fiber Coatings

2001 ◽  
Author(s):  
Patricia O. Iwanik ◽  
Wilson K. S. Chiu
Keyword(s):  
Heat Transfer ◽  
Optical Fiber ◽  
Gas Flow ◽  
Convection Heat Transfer ◽  
Fiber Surface ◽  
Chemical Vapor ◽  
Temperature Changes ◽  
Flow And Heat Transfer ◽  
Chemical Vapor Deposited ◽  
Fiber Coatings

Abstract A fundamental understanding of how reactor parameters influence the fiber surface temperature is essential to manufacturing high quality optical fiber coatings by chemical vapor deposition (CVD). In an attempt to better understand this process, a finite volume model has been developed to study the gas flow and heat transfer of an optical fiber as it travels through a CVD reactor. This study showed that draw speed significantly affects fiber temperature inside the reactor, with temperature changes up to 45% observed under the conditions studied. Multiple heat transfer modes contribute to this phenomena, with convection heat transfer dominating the process.

scholarly journals Manufacturing of Double Layer Optical Fiber Coating Using Phan-Thien-Tanner Fluid as Coating Material

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 147 ◽  
Author(s):  
Zeeshan Khan ◽  
Haroon Ur Rasheed ◽  
S.O. Alharbi ◽  
Ilyas Khan ◽  
Tariq Abbas ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
Fiber Optics ◽  
Double Layer ◽  
Polymer Melt ◽  
Deborah Number ◽  
Coating Process ◽  
Polymer Flow ◽  
Fiber Coating ◽  
Ptt Fluid

Modern optical fiber required a double-layer resin coating on the glass fiber to provide protection from signal attenuation and mechanical damage. The most important plastics resin used in coating of fiber optics are plasticized polyvinyle (PVC), low/high density polyethylene (LDPE/HDPE), nylon, and polysulfone. Polymer flow during optical fiber coating in a pressure type coating die has been simulated under non-isothermal conditions. The flow dependent on the wire or fiber velocity, geometry of the die, and the viscosity of the polymer. The wet-on-wet coating process is an efficient process for two-layer coating on the fiber optics. In the present study, the constitutive equation of polymer flow satisfies viscoelastic Phan-Thien-Tanner (PTT) fluid, is used to characterize rheology of the polymer melt. Based on the assumption of the fully developed incompressible and laminar flow, the viscoelastic fluid model of two-immiscible resins-layers modeled for simplified-geometry of capillary-annulus where the glass fiber drawing inside the die at high speed. The equation describing the flow of the polymer melt inside the die was solved, analytically and numerically, by the Runge-Kutta method. The effect of physical characteristics in the problem has been discussed in detail through graphs by assigning numerical values for several parameters of interest. It is observed that velocity increases with increasing values of ε D 1 2 , ε D 2 2 , X 1 , and X 2 . The volume flow rate increases with an increasing Deborah number. The thickness of coated fiber optic increases with increasing ε D 1 2 , ε D 2 2 , and δ . Increase in Brinkman number and Deborah number enhances the rate of heat transfer. It is our first attempt to model PTT fluid as a coating material for double-layer optical fiber coating using the wet-on-wet coating process. At the end, the present study is also compared with the published work as a particular case, and good agreement is found.

Coating Nano-TiO2 on Optical Fiber with Al(H2PO4)3 Adhesive

2007 ◽  
Vol 280-283 ◽  
pp. 485-488 ◽  
Author(s):  
Yu Hong Zhao ◽  
Jia Chen Liu ◽  
Shun Li ◽  
Yi Rong Liu
Keyword(s):  
Optical Fiber ◽  
Process Parameters ◽  
Coating Thickness ◽  
Fiber Surface ◽  
Tio2 Coating ◽  
Experimental Results ◽  
Coating Process ◽  
High Quality ◽  
Tio2 Photocatalysis

To meet the need of optical fiber photoreactor designed by mechanism of TiO2 photocatalysis, nanometer TiO2 was coated on the surface of optical fiber by dipping nude fibers into an Al(H2PO4)3-contained TiO2 slurry. Effects of slurry conditions, including content of TiO2 and addition of Al(H2PO4)3 adhesive, on coating thickness and quality were determined. Coating process, especially the effect of coating times, was also concerned. Based on the experimental results, fitting slurry conditions and process parameters were suggested for obtaining high-quality TiO2 coating on optical fiber surface.

Convective Transport in an Optical Fiber Coating Applicator for a Non-Newtonian Fluid

2005 ◽  
Author(s):  
Sang-Yeoun Yoo ◽  
Yogesh Jaluria
Keyword(s):  
Optical Fiber ◽  
Newtonian Fluid ◽  
Convective Transport ◽  
Uniform Grid ◽  
Fluid Viscosity ◽  
Cylindrical Domain ◽  
Uv Curable ◽  
Fiber Coating ◽  
Flow And Heat Transfer ◽  
Newtonian Case

Convective transport in an optical fiber coating applicator and die system has been simulated for a non-Newtonian fluid. Low density Polyethylene (LDPE) is employed for the numerical analysis, though ultraviolet (UV) curable acrylates are commonly used, because of lack of property information for acrylates and similar behavior of these two materials. The equations governing fluid flow and heat transfer are transformed to obtain flow in a cylindrical domain. A SIMPLE-based algorithm is used with a non-uniform grid. In contrast to the isothermal case, streamlines for the non-Newtonian fluid are found to be quite different for various fiber speeds. The temperature level in the applicator is much higher for the Newtonian case, due to the larger fluid viscosity and associated viscous dissipation. The shear near the fiber is found to be lower for the Newtonian fluid. As expected, the effects become larger with increasing fiber speed. A very high temperature rise is observed in the die, regardless of fiber speed. This study focuses on the non-Newtonian effects during the coating process, and several interesting and important features, as compared to the Newtonian case, are observed.

scholarly journals Double-layer optical fiber coating analysis in MHD flow of an elastico-viscous fluid using wet-on-wet coating process

2017 ◽  
Vol 7 ◽  
pp. 107-118 ◽  
Author(s):  
Zeeshan Khan ◽  
Saeed Islam ◽  
Rehan Ali Shah ◽  
Muhammad Altaf Khan ◽  
Ebenezer Bonyah ◽  
...  
Keyword(s):  
Viscous Fluid ◽  
Optical Fiber ◽  
Double Layer ◽  
Mhd Flow ◽  
Coating Process ◽  
Fiber Coating

Research about WO3/Pd Film Preparation for Reflection Type Optical Fiber Hydrogen Sensor

2014 ◽  
Vol 563 ◽  
pp. 127-130
Author(s):  
Xian Ling Deng ◽  
Chuan De Zhou ◽  
Ze Lun Li ◽  
Kang Cheng
Keyword(s):  
Surface Morphology ◽  
Optical Fiber ◽  
Sol Gel ◽  
Hydrogen Sensor ◽  
Coating Process ◽  
Temperature Shock ◽  
Good Surface ◽  
Sensitive Film ◽  
Film Preparation

Hydrogen sensitive film is the most important problem of the optical fiber hydrogen sensor, which directly affects the quality of the sensor sensitivity. In this paper, the process of sol-gel WO3/Pd coating was studied for the reflection type optical fiber hydrogen sensor. First, the materials for WO3/Pd sol, the devices and the detail steps of the sol preparation were introduced. Then the coating process of WO3/Pd sol was introduced, and the surface morphology of the film was analyzed. At last, experiments indicate the WO3/Pd film has good hydrogen sensitivity and show still good surface morphology after the temperature shock.

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