scholarly journals Computational Thermo-Fluid Analysis for the Effects of Helium Injection Methods on Glass Fiber Cooling Process in an Optical Fiber Manufacturing System

2014 ◽  
Vol 13 (2) ◽  
pp. 124-130 ◽  
Author(s):  
Shin Park ◽  
Kyoungjin Kim ◽  
Dongjoo Kim ◽  
Junyoung Park ◽  
Ho Sang Kwak
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
Manufacturing System ◽  
Cooling Process ◽  
Fluid Analysis ◽  
Injection Methods ◽  
Fiber Manufacturing

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.

Silica Preform Neck-Down Shape and Glass Fiber Drawing in Optical Fiber Manufacturing Process

2012 ◽  
Vol 488-489 ◽  
pp. 748-752
Author(s):  
Kyoung Jin Kim
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
Cooling Rate ◽  
Momentum Balance ◽  
Maximum Temperature ◽  
Cylindrical Shape ◽  
Fiber Drawing ◽  
Thin Glass ◽  
High Fiber ◽  
Fiber Manufacturing

The glass fiber drawing from the silica preform in a draw furnace is one of the important processes in a mass manufacturing system of optical fiber. When a preform of cylindrical shape is fed and heated in draw furnace and very thin glass fiber is pulled from the softened preform by applying a proper amount of draw tension, the preform experiences a drastic diameter change or neck-down shape. In this paper, neck-down shape formation and glass fiber drawing in heated preform is numerically modeled into one-dimensional formulation of momentum balance in order to examine the effects of the silica preform temperature such as the maximum temperature of preform and the cooling rate of glass fiber at high fiber drawing speed. The results show the typical shape of preform neck-down and the draw tension which is comparable to the industry value of approximately 100 g. Also, it is found that the axial location of glass fiber re-solidification sensitively depends on the cooling rate, while the draw tension is insensitive to the cooling rate of glass fiber.

scholarly journals Simultaneous Measurement of Temperature and Refractive Index Using High Temperature Resistant Pure Quartz Grating Based on Femtosecond Laser and HF Etching

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1028
Author(s):  
Na Zhao ◽  
Qijing Lin ◽  
Kun Yao ◽  
Fuzheng Zhang ◽  
Bian Tian ◽  
...  
Keyword(s):  
Refractive Index ◽  
High Temperature ◽  
Femtosecond Laser ◽  
Optical Fiber ◽  
Temperature Response ◽  
High Sensitivity ◽  
Xrd Analysis ◽  
Refractive Index Sensor ◽  
Compact Structure ◽  
Fluid Analysis

The optical fiber temperature and refractive index sensor combined with the hollow needle structure for medical treatment can promote the standardization of traditional acupuncture techniques and improve the accuracy of body fluid analysis. A double-parameter sensor based on fiber Bragg grating (FBG) is developed in this paper. The sensor materials are selected through X-ray diffraction (XRD) analysis, and the sensor sensing principle is theoretically analyzed and simulated. Through femtosecond laser writing pure silica fiber, a high temperature resistant wavelength type FBG temperature sensor is obtained, and the FBG is corroded by hydrofluoric acid (HF) to realize a high-sensitivity intensity-type refractive index sensor. Because the light has dual characteristics of energy and wavelength, the sensor can realize simultaneous dual-parameter sensing. The light from the lead-in optical fiber is transmitted to the sensor and affected by temperature and refractive-index; then, the reflection peak is reflected back to the lead-out fiber by the FBG. The high temperature response and the refractive index response of the sensor were measured in the laboratory, and the high temperature characteristics of the sensor were verified in the accredited institute. It is demonstrated that the proposed sensor can achieve temperature sensing up to 1150 °C with the sensitivity of 0.0134 nm/°C, and refractive sensing over a refractive range of 1.333 to 1.4027 with the sensitivity of −49.044 dBm/RIU. The sensor features the advantages of two-parameter measurement, compact structure, and wide temperature range, and it exhibits great potential in acupuncture treatment.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document