Analytic Study of Non-Newtonian Double Layer Coating Liquid Flows in Optical Fiber Manufacturing

2012 ◽  
Vol 224 ◽  
pp. 260-263 ◽  
Author(s):  
Kyoung Jin Kim ◽  
Ho Sang Kwak
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
Double Layer ◽  
Optical Fibers ◽  
Newtonian Fluid ◽  
Liquid Flow ◽  
Analytic Study ◽  
Fiber Drawing ◽  
Drawing Speed ◽  
Layer Coating

In mass manufacturing of optical fibers, the wet-on-wet polymer resin coating is an efficient process for applying double layer coatings on the glass fiber. This paper presents an analytic study on the behavior of non-Newtonian polymer resins in the double layer coating liquid flow inside a secondary coating die of the optical fiber coating applicator. Based the approximations of fully developed laminar flow and the power law model of non-Newtonian fluid, the coating liquid flow of two immiscible resin layers is modeled for the simplified geometry of capillary annulus, where the surface of glass fiber moves at high fiber drawing speed. The effects of important parameters such as non-Newtonian fluid properties, the coating die size, and fiber drawing speed are investigated on the resin velocity profiles and secondary coating layer thickness.

Helium-Injection Cooling of Hot Silica Glass Fiber in Optical Fiber Manufacturing System

2012 ◽  
Vol 157-158 ◽  
pp. 1301-1304
Author(s):  
Dong Joo Kim ◽  
Il Seok Oh ◽  
Ho Sang Kwak ◽  
Kyoung Jin Kim
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
Glass Fibers ◽  
Air Entrainment ◽  
Injection Rate ◽  
Fiber Drawing ◽  
Cooling Effectiveness ◽  
Drawing Speed ◽  
Cooling Unit ◽  
Fiber Manufacturing

In an optical fiber manufacturing process, glass fibers drawn from the heated silica preform in the furnace should be sufficiently cooled down close to ambient temperature. As the fiber drawing speed continues to increase for better manufacturing productivity, the glass fiber cooling becomes more difficult and the use of helium injection into the glass fiber cooling unit is required to greatly enhance the fiber cooling effectiveness. The present study numerically simulates the flowfield and heat transfer phenomena on the glass fiber cooling in order to investigate the effects of helium injection and fiber drawing speed on the fiber cooling effectiveness of glass cooling unit. The results found that the amount of air entrainment at the unit inlet is the significant factor that decides the cooling effectiveness by significantly lowering the helium purity in cooling gas. Also, at a given fiber drawing speed, there exists a critical helium injection rate and the fiber cooling does not improve any more, even if the helium injection rate increases above this critical value.

Steady flow and heat transfer analysis of MHD flow of Phan-Thien-Tanner fluid in double-layer optical fiber coating analysis with slip conditions

2017 ◽  
Vol 37 (7) ◽  
pp. 729-740
Author(s):  
Zeeshan Khan ◽  
Saeed Islam ◽  
Rehan Ali Shah
Keyword(s):  
Heat Transfer ◽  
Optical Fiber ◽  
Double Layer ◽  
Optical Fibers ◽  
Fluid Model ◽  
Experimental Results ◽  
Slip Conditions ◽  
Fiber Coating ◽  
Layer Coating ◽  
Ptt Fluid

Abstract Modern optical fibers require a double-layer coating on the glass fiber in order to provide protection from signal attenuation and mechanical damage. The most important plastic resins used in wires and optical fibers are plastic polyvinyl chloride, low- and high-density polyethylene, nylon, and polysulfone. One of the most important things that affect the final product after processing is the design of the coating die. In the present study, double-layer optical fiber coating is performed using melt polymer satisfying the Phan-Thien-Tanner (PTT) fluid model in a pressure-type die. The fluid is electrically conducted in the presence of applied magnetic field. Wet-on-wet coating process is applied for double-layer optical fiber coating. The assumption of fully developed flow of PTT fluid model, two-layer liquid flows of an immiscible fluid, is modeled in an annular die of length L, where the fiber is dragged at a higher speed. The equations characterizing the flow ad heat transfer phenomena are solved exactly and the effects of emerging parameters are shown with the help of graphs. It is interesting to remark that an increase in the non-Newtonian parameters increases the velocity in the absence or presence of slip parameters, which coincides with the results reported earlier. Also, the effect of important parameters such as Deborah numbers, slip parameters, magnetic parameter, characteristic velocity, radii ratio, and Brinkman numbers on the axial velocity, flow rate, thickness of coated fiber optics, and temperature distribution are investigated. Furthermore, the results were compared with the experimental results already published. To the best of our knowledge, no such analysis of the double-layer coating flows of PTT fluid using slip conditions is available in the literature. At the end, the result of the present work is also compared with the experimental results already published by taking λ → 0 (non-Newtonian parameter).

A Computational Investigation of Thermal Effects on Resin Coating Flows in an Optical Fiber Drawing System

2011 ◽  
Vol 110-116 ◽  
pp. 1080-1086
Author(s):  
Kyoung Jin Kim ◽  
Ho Sang Kwak ◽  
Jin Su Choi
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Thermal Effects ◽  
Resin Flow ◽  
Fiber Drawing ◽  
Coating Flows ◽  
Drawing Speed ◽  
Drawing System ◽  
Optical Fiber Drawing ◽  
Fiber Manufacturing

In manufacturing optical fibers, there has been intense research efforts of continually increasing fiber drawing speed to improve productivity. However, higher speed fiber drawing poses new challenge in many areas of optical fiber manufacturing. In this paper, thermal effects on coating resin flow in an unpressurized coating applicator are studied numerically. Present simulation results found that higher fiber drawing speed leads to severe viscous heating in coating resin flow and significant increase of resin temperature, which in turn leads to substantial viscosity decrease. These thermal effects profoundly alter the resin flow patterns and velocity profiles in the coating die and they should be considered in controlling the final coating thickness.

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.

High-Speed Glass Fiber Drawing from Heated and Softened Silica Preform in an Optical Fiber Draw Furnace

2012 ◽  
Vol 8 (1) ◽  
pp. 439-444
Author(s):  
Ho Sang Kwak ◽  
Dongjoo Kim ◽  
Kyoungjin Kim
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
High Speed ◽  
Fiber Drawing

Numerical Simulation of Transport in Optical Fiber Drawing With Core-Cladding Structure

2004 ◽  
Author(s):  
Chunming Chen ◽  
Yogesh Jaluria
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Numerical Results ◽  
Fiber Drawing ◽  
Zonal Method ◽  
The Core ◽  
Optical Fiber Drawing ◽  
Cylindrical Furnace ◽  
Purge Gas ◽  
Energy Equations

Optical fibers are typically heated and drawn from silica preforms, which usually consist of two concentric cylinders called the core and the cladding, in a high-temperature furnace. For optical communication purpose, the core always has a higher refractive index than the cladding. In order to investigate the effect of core-cladding structure on the optical fiber drawing, a numerical model has been developed in this work. Axisymmetric flows of a double-layer glass and aiding purge gas in a concentric cylindrical furnace are considered. The thermal and momentum transport in both glass layers and gas are coupled at the interface boundaries. The neck-down profile is generated using an iterative scheme. The zonal method is applied to model the radiation transfer in the glass preform and the gas. Coordinate transformations are used to convert complex domains into cylinders. Stream function, vorticity and energy equations for the core, the cladding and the purge gas are solved by finite different methods using a false transient method coupled with an alternating direction implicit (ADI) method. A second order differencing scheme is used for discretization. The numerical results are validated by comparing with experimental and numerical results available in the literature.

scholarly journals Twisted Silica Microstructured Optical Fiber with Equiangular Spiral Six-Ray Geometry

Fibers ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 27
Author(s):  
Anton V. Bourdine ◽  
Alexey Yu. Barashkin ◽  
Vladimir A. Burdin ◽  
Michael V. Dashkov ◽  
Vladimir V. Demidov ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Near Field ◽  
Outer Diameter ◽  
Microstructured Optical Fibers ◽  
Transmission Parameters ◽  
Microstructured Optical Fiber ◽  
Drawing Speed ◽  
Ray Geometry ◽  
Equiangular Spiral

This work presents fabricated silica microstructured optical fiber with special equiangular spiral six-ray geometry, an outer diameter of 125 µm (that corresponds to conventional commercially available telecommunication optical fibers of ratified ITU-T recommendations), and induced chirality with twisting of 200 revolutions per minute (or e.g., under a drawing speed of 3 m per minute, 66 revolutions per 1 m). We discuss the fabrication of twisted microstructured optical fibers. Some results of tests, performed with pilot samples of designed and manufactured stellar chiral silica microstructured optical fiber, including basic transmission parameters, as well as measurements of near-field laser beam profile and spectral and pulse responses, are represented.

Effects of Air Entrainment on Glass Fiber Cooling with Helium Injection in Optical Fiber Drawing

2013 ◽  
Vol 19 (8) ◽  
pp. 2215-2219 ◽  
Author(s):  
Dongjoo Kim ◽  
Il-Seok Oh ◽  
Ho Sang Kwak ◽  
Kyoungjin Kim
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
Air Entrainment ◽  
Fiber Drawing ◽  
Optical Fiber Drawing
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