JPS58502200A - Equipment for glass fiber drawing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Equipment for glass fiber drawing machine Technical field The present invention relates to an apparatus for an optical fiber drawing machine.

Background technology The optical fiber was heated to a molten, semi-liquid state in a double crucible. Manufactured by continuously drawing optical fiber base material. as soon as possible after drawing , the fibers are coated to increase their strength and reeled. Can be removed without risk of rupture when wound up and subsequently built up into cables. be made manageable.

This coating typically consists of drawn glass fibers, usually thermoset silicone. To pass the coating material, which is cone rubber, through the solution bath as quickly as possible. It is carried out by This coating method is suitable for fine fiber dimensions. It works well against.

Demonstration of invention However, major fiber dimensions such as 200-600μ For silicone rubber, the insertion into the silicone rubber solution bath is done very close to the drawing position. The coating was found to be non-uniform when mixed. When entering the solution tank The fiber has a high enough heat to instantly cure the silicone rubber. It turns out. Therefore, the solution bath should be moved further away from the line drawing position and Avoid the risk of fine rack formation on the fibers and contamination of their surfaces. This inevitably led to an increased risk of contamination due to garbage and moisture. Said As the distance increases, the fiber diameter decreases due to the weight of major fibers. Because of this, the drawing speed of major fibers decreases. adjacent to the delineation position It is difficult to arrange a forced cooling device for the fiber. Because it causes rupture. This is because the lateral force that causes this is easily generated on the fiber.

According to the invention, cooling is significantly improved and at the same time the fibers are cooled by the cooling medium. Line drawing position and coating so that it can be drawn out without hindrance It became possible to keep the distance between the solution tank and the solution tank short.

The fiberglass drawing machine tail device according to the invention is located after the drawing position. The features including the cooling device are clear from the appended claims.

Brief description of the drawing The invention will be explained in more detail with reference to the accompanying drawings. The drawing is an optical fiber Figure 1 schematically shows the drawing and coating equipment for the .

Mode for carrying out the invention In the drawing, the number 10 indicates a glass melting crucible. The one shown is Ericsson Review magazine (Er1csson Review) Ai, 1980. Pages 12 and 16 The paper described in [Optical Fibers J ("0ptical Fibers")] shows a so-called double crucible of the type described in . This thing is mainly intended to produce optical fibers with a so-called step-shaped refractive index profile However, it can also be used to produce optical fibers with a squared refractive index profile.

This double crucible has a refractive index that forms the core of the glass fiber. An inner crucible 11 containing high-temperature melting glass 13 and a glass fiber cracker. A molten glass 14 with a low refractive index is inserted to form a casing portion. and an outer crucible 12. The melting glass 13 coming out of the inner crucible is the inner crucible. slowly outward through the nozzle 15 of 11 and the outer crucible and the outer nozzle 16. passed through and drawn out. When the molten glass 13 passes through the latter nozzle, the core The chamber is surrounded by an outer crucible glass. The melting glass is the outer nozzle 1 6, a meniscus 17 is formed. And from here the glass is Fine fibers 18 are drawn using a Pustan device 26 . The delineated frame The fiber consists of 307 parts made of molten glass 13 and a crack made of molten glass 14. It will have a do part.

The outer diameter of the drawn fiber depends on the drawing speed of the capstan device and each nozzle 1. 5.16, and the outflow rate is determined by the outflow rate when each dissolution Determined by glass temperature and viscosity. The outer diameter is measured by a wire diameter measuring device 19. . The wire diameter measuring device uses a suitable well-known control device to adjust the drawing speed of the capstan device. control.

After drawing, the fiber is highly susceptible to scratches and contamination; The protective coating must therefore be applied as quickly as possible. protection code The coating is coated with a suitable liquid coating, e.g. thermoset silicone rubber. The treatment is carried out in a container 20 containing . The liquid coating is applied to the fiber. After the fiber is deposited and when the fiber is withdrawn from the container 20, a suitable Cured in a heating device. A cooling chamber 21 through which the drawn fiber passes is , is arranged between the withdrawal nozzle 16 and the container.

The cooling chamber 21 includes a tube 22 made of a porous material with very small through holes. include. The material may be, for example, a copper alloy made by sintering or other methods. It may also be a suitable porous metal such as. In addition, the material has, for example, fine pores. May be of other types like ceramics or plastics .

A container 23 is placed over the outside of the tube and is preferably filled with dry nitrogen gas. A supply pipe 70 communicating with a source of compressed gas is in communication with the interior of the container. Ru.

The gas passes through the porous tube 22 and enters the gap 25 around the fiber. . A large number of small holes provided in the tube 22 allow the flow of gas into the gaps 2, 5. is distributed very evenly around the fiber, whereupon the fiber The bar will be subjected to no transverse forces. gas flow upwards so that the fibers do not flow towards the Prevents premature cooling before the wire is fully drawn For this purpose, the upper opening of the tube 22 is provided with a canopy, such as an iris-shaped opening. It is provided. The fiber passes into the tube 22. Only the smallest possible holes are drilled. Due to this cooling effect, the The distance between the outlet nozzle 16 and the container can be reduced considerably. Preferably When cooling is performed using a dry gas, which is nitrogen gas, the fibers are The risk of absorbing is further reduced. The absorption of water causes a slight crack in the fiber. By advancing the rack in the upright direction, the strength of the fiber is significantly reduced.

This rapid cooling of the fiber reduces the compressive stress in the fiber. is confined within the outer layer, thereby allowing the fiber to Tensile strength increases.

When the fiber then passes through the solution bath, the fiber is no longer heated there. The coating is cooled to such an extent that no curing occurs; It will be evenly distributed around the ment.

Claims (1)

[Claims] 1 Equipment for glass fiber drawing machine that cools glass fiber after drawing it a cooling device surrounding said fibers (18) and comprising a tubular container; The inner wall (22) of the cooling chamber is made of a porous material having small through holes. The cooling chamber is in communication with a source of compressed gas (24), and the cooling chamber is in communication with a compressed gas source (24). The compressed gas penetrates the inner wall (22) and then passes through the fibers. (18) is ejected as a uniformly distributed flow. Equipment for glass fiber drawing machine. 2. The porous material according to claim 1, wherein the porous material includes sintered metal. Device. (b) The compressed gas includes dry nitrogen gas, as set forth in claim 1. equipment.