Manufacturing method of preform loose body

Abstract

The present application discloses a method for manufacturing a prefabricated rod loose body, which includes the following steps: 1) clamping the two ends of the mandrel on two chucks respectively; 2) moving the blowtorch under the mandrel back and forth to obtain the loose body; 3) When the outer diameter of the loose body exceeds the preset critical value, inject gas symmetrically to the loose body on both sides of the lower part of the loose body. The injection direction of the gas is aligned with the mandrel axis, and the closer to the middle of the loose body, the gas The faster the injection speed is; 4) After the outer diameter of the loose body reaches the set value, the blowtorch stops working; 5) After cooling the loose body, stop spraying gas to the loose body. In the manufacturing method of the present application, the gas is injected symmetrically to the loose body on both sides of the lower part of the loose body, and the injection direction of the gas is aligned with the mandrel axis, so that both sides can generate an oblique upward force on the loose body, and the symmetrical arrangement makes the final The resultant force is basically vertically upward. This method can make the overall force effect of the loose body good, and no bending and hanging phenomenon will occur in the middle.

Description

technical field [0001] The invention relates to the field of optical fiber preform rods, in particular to a method for manufacturing loose preform rods. Background technique [0002] In the OVD method, the blowtorch mixes silicon tetrachloride or octamethylcyclotetrasiloxane vaporized gas with oxygen, and sprays it together with hydrogen (or methane) and oxygen flames to the rotating mandrel. Under the action of heat, the raw materials A hydrolysis reaction occurs to generate silica, and the dust particles generated by the pyrolysis of silica particles are adsorbed layer by layer on the rotating mandrel passing through the flame to obtain a loose body, which is then vitrified to obtain a preform. [0003] Such as figure 1 As shown, when the loose body is manufactured by the existing OVD method, the mandrel bears the greatest force in the middle region of the loose body, and is easy to bend and hang, which will eventually affect the quality of the preform. Contents of the ...

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Problems solved by technology

[0003] like figure 1 As shown, when the loose body is manufactured by the existing OVD method, the mandrel bears the greatest force in the middle area of ​​the loose body, and is easy to bend and hang, which will eventually affect the quality of the preform

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