What is Fiber Optic Coloring? Types of Fiber Optic Coloring Method

What is fiber optic coloring? Coloring means applying a layer of color coating on the outside of a coated fiber. Its composition contains photoinitiators, which can absorb a certain amount of ultraviolet light to produce a chemical reaction. The coating changes from liquid to solid. So that it is tightly and firmly attached to the optical fiber, which is convenient for optical fiber identification and splicing.

Why do We need to Fiber Optic Coloring?

The number of optical fibers in the optical cable structure has developed from one optical fiber per unit to 2, 4, 8, 12, 24, 48, 144, 288 and other optical fibers. Due to this structural change, it has brought many inconveniences to the splicing, maintenance and inspection of optical fibers. In order to facilitate the marking and identification of optical fibers. Some identification method must be adopted for optical fibers. So that people can distinguish them.

Methods of Fiber Optic Coloring

1. Ultraviolet Curing Furnace (UV curing device)

The ultraviolet curing furnace is mainly composed of a reflector, a furnace shell, a UV lamp tube and a quartz glass tube. In order to improve the UV curing degree, a nitrogen flushing system is also designed. Its purpose is to use inert gas to flush the quartz glass tube of the UV curing furnace. Prevent oxygen from penetrating into the UV curing area. Oxygen contact with fiber color ink will weaken the chemical cross-linking reaction. This will increase the curing time and reduce the maximum curing speed.

2. UV curing

Add photoinitiator (or photosensitizer) to the specially formulated uv coloring resin, and absorb the high-intensity ultraviolet light in the ultraviolet (UV) led light curing equipment to initiate polymerization, cross-linking and grafting reactions. The resin (UV coating, ink, adhesive, etc.) is converted from liquid to solid within a few seconds. This process is called UV curing.

(1) UV lamp for fiber coloring

The maximum life of the UV lamp is generally 800-1000 hours, and it should be replaced after reaching this time. Because the intensity of the ultraviolet light emitted by the UV lamp during this period becomes weaker. Which will affect the curing effect. It is also recommended that during the service life. According to the production environment (dust content in the air), clean the reflector on the surface of the lamp with anhydrous ethanol at an appropriate time. And then turn the UV lamp 90 degrees. This is conducive to the effective radiation of all UV rays to the UV ink or lamp oil, ensuring a certain degree of penetration.

(2) Emission hood

Generally, a focusing type of reflector hood is used. The structural feature of this reflector is that the reflected UV light energy is concentrated. The light curing efficiency is high. Which is conducive to the curing of the colored ink. The reflection power of the reflector is more than 80%.

(3) Using quartz glass tubes for optical fiber coloring

In the actual production process, when the coated optical fiber passes through the UV curing furnace. In order to protect it from air pollution and vibration, it is usually passed through a quartz glass tube with a diameter of about 2cm. The projection rate of the central tube is particularly important in the actual production. The central tube should be checked and replaced regularly.