DE20320801U1 - Device for producing optical glass fibers from preforms comprises heating bushings having a matrix-like arrangement for simultaneously receiving several preforms - Google Patents

Abstract

Device for producing optical glass fibers (5) from preforms (11) comprises heating bushings (15) having a matrix-like arrangement for simultaneously receiving several preforms. The glass fibers drawn from the heating bushings are received by a drawing and sizing device (3). Independent claims are also included for the following: (1) Process for the production of glass fibers from performs using the above device; and (2) Heating bushing used in the above device.

Description

The The invention relates to a heating bush for use in a fiber furnace for producing optical glass fibers from preforms, in particular from Multi-component glass fibers. The fiber oven is usually with a tracking device for holding and tracking the preforms in the heating bushes and a drawing and Beschlagungsanlage to continue the glass fibers provided to a confectioning device.

Of the The invention relates to methods for producing glass fibers used from preforms, wherein the preforms with a tracking device be inserted into the Heizbuchsen of the fiber furnace and where the the Heizbuchsen drawn glass fibers on a downstream cooling line chilled and over a drawing system to be continued to a packaging device.

devices and methods of making glass fibers are known in the art known. This preforms are introduced in Heizbuchsen and melted. The glass flows from the preforms continuously and is below the fiber furnace pulled out of the Heizbuchsen.

preforms consist at least of a rod of a specific glass material with a predetermined diameter. Especially for use of multicomponent glass fibers in glass fiber bundles, however, it is necessary that the glass fibers have a certain quality in terms of diameter each fiber or the diameter variance of several have simultaneously produced glass fibers, with an optimal reflectivity for the through the fiber-guided light is necessary. These properties are used in multi-component glass fibers by multilayer preforms achieved, which include a core rod and, for example, a jacket tube. The pulled glass fibers have a core and a core connected coat on. Thereby the high reflection properties become produced by the jacket, which has a certain refractive index. The core rod is made of a material with a higher refractive index than that of the cladding material to the light-conducting and optical To ensure properties.

At the Melting of the preform is accompanied by dripping of the first glass drop the jacket material over The core material is pulled and the two materials unite.

Around the material thicknesses To keep constant and optimal optical properties of different Producing materials in the glass fibers, it is necessary that the diameters of the glass fibers are kept constant. Furthermore are the temperature gradients in the fiber furnace of vital importance for the optical and mechanical Properties of the resulting glass fibers.

For this In the prior art manufacturing methods are distinguished, which essentially on the nature and quality of the glass fibers to be produced or the rate of fiber production and the number depend on the glass fibers to be produced at the same time.

Out US 2003/0079501 A1 is a multiple puller for glass fibers known, which are drawn from single-layer preforms. These preforms are usually made of quartz glass, which at 2000 ° C in a Ziehofen is melted. From the Ziehofen a fiber is withdrawn, whose Diameter in a drawing tower with appropriate means regarding the accuracy checked or measured and then is coated with a polymer material. After that, the fiber becomes wound up on a take-up spool. The fibers thus produced made of quartz glass are used in telecommunications technology respectively for the data transfer used.

she be because of the increased Demands on diameter accuracy and because of it necessary test measures always pulled individually and after the Ziehofen also individually processed. The improvements recognized with US 2003/0079501 A1 exist opposite the known single fiber production therein, several separately working for themselves To switch devices for the production of individual fibers in parallel, to produce a corresponding number of glass fibers simultaneously to be able to.

These Production method is for the production of multicomponent glass fibers unsuitable, since usually a variety of glass fibers are used in glass fiber bundles, which other in terms of diameter accuracy and coating To meet requirements to have. It has been proven that economical production such fiber optic bundle with single-fiber pulling devices, even if they are connected in parallel to several, not possible is.

In particular, it has proved to be a disadvantage of such devices that, despite the parallel connection of a plurality of individual fiber drawing systems, the number of glass fibers remains considerably below what is necessary. For the economic production of glass fiber bundles, a large number of individual fibers should be able to be produced simultaneously. Also, the single-fiber-related post-processing is included in the prior art device associated costs, so that a generation of fiber bundles for optical systems would be uneconomical.

Compared to the for the Data transmission used Glass fibers are less affected by multicomponent glass fibers quality of the individual fibers than on the entire fiber bundle. Play alongside unlike data transmission fibers, for the Use of glass fiber bundles from multicomponent glass fibers economy considerations one much bigger role.

It has been shown that in single guide of the glass fibers, as in the aforementioned prior art, these requirements not guaranteed can be.

task The invention is therefore the disadvantages of the prior art to avoid and a Heizbuchse for a fiber furnace for producing optical To provide glass fibers, with which the above-described quality requirements be fulfilled can, and with a sufficient number of glass fibers, preferably from multilayer preforms, can be produced simultaneously.

A solution The object is provided by the claim 1. Inventive developments and embodiments of the Heizbuchse are characterized by the subclaims Provided.

It is inventively provided that the Heizbuchsen in the fiber furnace a matrix-like arrangement for simultaneous Have record of multiple preforms and that from the Heizbuchsen pulled glass fibers band-shaped adjacent to each other of the drawing and Beschlagungsanlage receivable are.

The Arrangement of the heating bushes ensured doing that the glass fibers with a small offset distance to each other can be pulled out of the fiber oven. It is possible, the Accordingly, deflect glass fibers on a downstream roller.

Of the Offset of the glass fibers is achieved by the main matrix axes are arranged at a predetermined offset angle to each other. For this is provided in an advantageous manner that the Heizbuchsen in the fiber furnace rhomboid are arranged. It is further provided that the distance between the same immediately adjacent Heizbuchsen on each matrix axis is. Furthermore, it is provided that the Heizbuchsen in a Level are arranged.

With the device according to the invention can a variety of preforms are guided synchronously through the heating bushes and the glass fibers produced in the fiber furnace with a predetermined Pulling speed from the preforms located in the heating bushes to be pulled. It is inventively provided that the glass fibers on at least one downstream guide roller, without touching and to be crossed, to be diverted. Thus, the glass fibers in their Entity with the same pulling speed from the heating bushes pulled the fiber oven.

Thereby, that everyone from the tracking device out Preform is assigned a Heizbuchse, becomes a simultaneous Pulling fiberglass out of all preforms allows.

A advantageous embodiment of the device according to the invention thereby made available, that the fiber furnace has a number of at least 110 heating bushes. It is a cheap Arrangement achievable in that the matrix structure 10 Heizbuchsen in the direction of a matrix main axis and 11 heat sockets in the direction the other main matrix axis has. It turned out that that an advantageous utilization of the heating power of all Heizbuchsen with a larger number can be better optimized at Heizbuchsen. This will cause unwanted temperature fluctuations already kept structurally low. In this embodiment are the glass fibers of one half of the fiber furnace on each a deflection roller and each led to a Beschlagungsanlage.

Around the wished and to ensure required temperature profile is provided that the fiber oven has a temperature control and that the Temperature control Individual controls of the inside of the heater includes. Thus, over the Temperature control both the total temperature and the temperatures the individual heating bushes are controlled and regulated. This allows an individual adaptation of the temperature profile to external and internal influencing factors.

In order to determine the temperatures in each case and to change the temperatures of the individual heating bushes individually, it is proposed according to the invention that the individual controls have measuring and compensating means for adjusting the temperatures of the heating bushes relative to the adjacent heating bushes. For this purpose, sensors are provided within the Heizbuchsen, which are connected to the temperature control. By means of the sensor values, the temperatures of the individual heating bushes are regulated. All heating bushes are heated to a setpoint, which lies in the range between about 800 ° C and 1100 ° C. With the individual regulation can Thus be achieved in an advantageous manner that all heating bushes are controlled individually to the desired value. Disturbance variables which cause the heating bushes to have different temperatures from one another and altogether from the setpoint value are compensated by respective offset settings. All heating bushes are regulated to the same setpoint within a temperature band of about 1 ° C. To compensate for temperature differences between the heat sockets with each other, the temperature difference is recorded at regular intervals for each Heizbuchse and deducted the determined value of the offset or attributed to him. Thus, long-term effects, such as aging of the thermocouples and Heizbuchsen or other disturbances from outside the heating bushes, also be compensated by the offset setting. The compensating means comprise heating and cooling elements, for example electronic components, with which the temperatures in the heating bushes can be increased or decreased as needed. Advantageously, it is thus possible to set defined states of the Heizbuchsen and thus the overall system of the fiber furnace.

Of Furthermore, it is proposed according to the invention that each Heizbuchse at least one heating element, preferably several separately controllable heating coils, and that between the heating element and the preform at least one diffuser for scattering the heating radiation is arranged. Advantage of this embodiment is that with Several heating coils on the one hand a precisely calculated temperature profile can be adjusted in the Heizbuchse. For another, steep ones Temperature gradient through smoothed the diffuser. It is provided that the diffuser is preferably a quartz tube and that the preform of the tracking device through the quartz glass feasible is.

Within the Heizbuchse, but especially within the quartz tube, can undesirable flow conditions result, which lead to that the preform is exposed to cold air. To avoid this is proposed according to the invention, that each Heizbuchse fluid for generating a laminar air flow in the Heizbuchse. This makes it possible to set advantageously pre-calculated flow conditions. It is provided that the fluid is preferably in one piece with the diffuser connected in the lower part of the Heizbuchse arranged renewal include, which is free of heating elements. This causes that can form an air buffer under the Heizbuchse, which by the heating radiation is heated. The heated air is in directed the heating bush. Thus the flow velocity of the introduced Air not undesirable increases, is provided according to the invention, that the fluid at least one flow aperture at the top of the heating bushes, which for the air vent ensures an annular gap with a predetermined gap width around the preforms. Through the flow aperture Is it possible, the laminar velocity of the air flow by fixing the annular gap in the upper area of the heating bush. It is also possible to have several flow aperture with different, to be covered each of the annular gaps matched outside diameter to use. It can thus easily in an annular gap different diameters adapted from preforms or to changes the flow conditions in a heating bush during of the drawing process are reacted. It is with an advantageous embodiment provided that the heating bushes throughout the fiber furnace the same Have annular gaps.

According to the invention will continue suggested that the tracking device a support disc with individual suspensions has to accommodate the individual preforms. This allows every preform hung individually become. With a small number of glass fibers to be produced can thereby individual single suspensions also unpopulated stay.

It is also provided in an advantageous manner that the individual suspensions on the support disc a corresponding with the Heizbuchsenanordnung have a matrix-like arrangement. This will make it possible for that the preforms are axially symmetrical to the axes of Heizbuchsen inserted and deviations of the edge distance of the preforms to their respective Heizbuchse be avoided.

In Advantageously, the melting together of the sheath and core material thereby improving that each individual suspension has a vacuum connection for connecting the preform to a central vacuum system. The vacuum draws between the materials Air off, allowing air pockets between the layers can be avoided.

Around a synchronous feed arranged all in the support plate Preforms and therefore a reliable one To achieve production of largely identical fiber diameters is proposed according to the invention, that the support disk for the advance of the preforms by means of threaded spindle and leadership of a geared motor can be driven and braked.

there it is envisaged that the support disc manually and / or automatically can be moved in an operating position, so that the support plate after the drawing process quickly moved back to its operating position is.

It is further provided according to the invention, that the fiber furnace has a flow collar on Having output side end of the Heizbuchsen, by means of a Air buffer for the delayed cooling of the Glass fibers can be generated. It has a beneficial effect proved that with this flow collar targeted cooling profiles for the glass fibers are reachable.

It is provided that the fiber oven a cooling section for cooling the Subordinate glass fibers. It has proved to be advantageous that the cooling section a funnel through which the glass fibers to the drawing and Beschlagungsanlage feasible are. The funnel is downstream of the fiber furnace and below of the flow collar in the cooling section positioned so that when setting up the device, the first molten glass drops of preforms targeted to the furnishing place are feasible on the drawing and Beschlagungsanlage. The glass drops when falling down on the funnel and slip with the following fiber through the funnel to the drawing and coating plant, where they are preferably added manually and in the Beschlagungsanlage can be placed on sizing rollers.

It has proved to be advantageous in that the glass fibers each Oven half over each a sizing roll feasible are. Thus it is achieved that a large number of glass fibers produced simultaneously and can be further processed. The glass fibers are each case led to the appropriate sizing roll, arranged band-shaped side by side and evenly with Sizing provided. It is envisaged that the glass fibers do not touch.

A further advantageous embodiment of the device is characterized achieved that the sizing rolls at a predetermined angle are arranged to the main matrix axes. Thus, the device becomes facilitated the device at the start of drawing and continues to achieve that the glass fibers have sufficient distance from each other while they are be coated.

Of the described fiber furnace, which includes the Heizbuchse invention, allows that the glass fibers with a predetermined constant diameter pulled the heating sockets and over the cooling section cooled in a predetermined manner and that by means of arranging the heating bushes a contact and crossing-free pulling of the glass fibers is ensured. The glass fibers are doing this with constant pulling speed from the Heizbuchsen drawn. The optical requirements for the glass material of the glass fibers and the physical properties of the fiber bundles produced therewith This sufficiently ensures that fluctuations The pulling speed of the individual glass fibers are avoided. In doing so, according to the mass flow law The relationship the mass of the molten glass material and the mass of the as Glass fiber withdrawn glass material kept constant.

This is achieved by having each preform with a controlled temperature profile in the associated Heizbuchse and / or feed the support plate is pulled. Furthermore, it is proposed that the from the Heizbuchsen drawn glass fibers are cooled over a predetermined temperature profile.

there ensures according to the invention the special geometric Arrangement of the heating bushes for that the glass fibers without touching each other or crossed with each other to be pulled out of the fiber furnace and passed over the cooling section can. Furthermore, it is thus possible after the cooling section that the glass fibers strip-like on the downstream finishing rollers of a Beschlagungsanlage evenly with Sizing agents are wetted.

The Pulling the glass fibers is done by making the glass fibers be pulled by a puller roller with the same pulling speed. The glass fibers are as already on the sizing rolls also contact and without crossing on the peel-off roller. After that, the Glass fibers bundled and be assembled, so that fiber bundle or fiber cable with a big one Number of glass fibers can be produced simultaneously.

It It is suggested that the pulling speed of the peel-off roller and the feed of the support plate by means of an electronic data processing system be managed. Furthermore is provided that the temperatures in the Heizbuchsen means the electronic data processing system are regulated. Finally is provided that the glass fibers assembled without feedback become. Preferably, the glass fibers by means of a minor role guided around the peel roll, one as possible size To obtain Abziehhreibung on the roll surface. From the supporting role are the glass fibers to the non-reactive Assembly device guided, which prevents the assembly of forces several or individual glass fibers are exercised, which the constancy of Pulling speed and thus the diameter accuracy in question put.

Finally, to achieve the object of the invention Heizbuchsen with the above-described features for Verwen proposed in fiber furnaces.

The Invention will be explained below with reference to the drawing. It demonstrate

1 a sketch of the device according to the invention;

2 the fiber furnace in a plan view from above with the inventive arrangement of the heating bushes;

3 a Heizbuchse in cross-section through the longitudinal axis;

4 a Heizbuchse after 3 while pulling a preform.

In 1 is the device according to the invention 1 with the fiber oven 2 and a drawing and Beschlagungsanlage 3 shown. The drawing and coating plant 3 is a packaging device 4 downstream, which reaction-free, the glass fibers produced 5 as a fiber bundle 6 on take-up reels 7 assembled.

Between the fiber oven 2 and the paint shop 3 is the cooling section 8th interposed, with the glass fibers 5 through a funnel 9 be passed. The cooling section 8th has a fiber oven 2 immediately downstream flow collar 10 on, which serves that the glass fibers 5 be cooled with a predetermined temperature profile.

The glass fibers 5 become of preforms 11 deducted, the preforms by means of a tracking device 12 in the fiber oven 2 be introduced. These are the individual preforms 11 on a support disc 13 the tracking device 12 attached. The support disk 13 is in a leadership 14 by means of a in the 1 not shown gear spindle, preferably by means of a ball screw, guided and is driven by a geared motor. This is the support disk 13 during normal tracking of the preforms 11 driven by the feed provided for pulling. Will the pulling of the glass fibers 5 finished, the support disc can 13 manually or, for example, at the end of the preforms 11 , are also automatically moved back to an operating position, in which removed the Preformreste and new preforms 11 on the support disc 13 can be attached.

The fiber furnace 2 has a variety of heating sockets 15 on which in 3 and 4 be explained in more detail. The preforms 11 be from the tracking device 12 in a way in the Heizbuchsen 15 introduced that the glass fibers 5 continuously over the Beschlagungsanlage 16 from the drawing plant 17 for confectioning device 4 can be performed. The drawing system 17 has a peel roller for this purpose 18 on, with the glass fibers 5 from a supporting role 19 Non-contact next to each other around the peel-off roller 18 be guided so that the glass fibers 5 from the peel roller 18 be pulled at the same pulling speed. So can the stiction of the glass fibers 5 at the puller roller 13 be held optimally and it will be all glass fibers 5 with largely identical pulling speed from the heating bushes 15 of the fiber furnace 2 drawn.

An electronic data processing system controls the drawing process accordingly depending on the feed of the tracking device 12 and the pulling speed. The packaging device 4 automatically adjusts itself to that of the peel-off roller 15 predetermined speed at which the fiber bundle 6 wound up who can.

The glass fibers 5 be in front of the puller 18 through the Beschlagungsanlage 16 drawn. Here are the glass fibers 5 band-like juxtaposed by two sizing rollers 20.1 . 20.2 added. It is envisaged that the glass fibers 5 one half each of the fiber furnace 2 over one of the sizing rollers 20.1 . 20.2 be guided. The sizing rolls 20.1 . 20.2 are partial, ie up to 45% in a storage container 21 immersed. The glass fibers 5 be over the surface of sizing rollers 20.1 . 20.2 evenly wetted with sizing agent. Subsequently, the glass fibers 5 , further arranged band-like juxtaposed, from the peel-off roller 13 added.

In 2 is the fiber furnace 2 with the inventively provided arrangement of the heating bushes 15 shown. The heating bushes 15 are in a plane in the form of a matrix 22 arranged. The matrix 22 has angularly arranged matrix axes 23 . 24 on, at their crossing points the Heizbuchsen 15 are arranged. In every direction of the matrix axes 23 . 24 are the adjacent heating sockets 15 arranged at the same distance from each other. The matrix axes 23 . 24 are arranged at a predetermined angle α to each other. The angle α is chosen according to the invention smaller than 90 °.

In an advantageous embodiment, the fiber furnace 2 a matrix structure of 10X 11 with a total of 110 heating sockets 15 on. In each case, half of the preforms 11 drawn glass fibers 5 about one in the 2 not shown sizing roll 20.1 . 20.2 guided. The sizing rolls 20.1 . 20.2 are arranged at a predetermined angle to the corresponding matrix main axis to an optimum distance of Glasfa fibers 5 on the sizing roll 20.1 . 20.2 to ensure.

In 3 is a heating bush 15 shown in cross section to the longitudinal axis A. The heating bush 15 points at the top 25 an inner and outer bezel 26.1 . 26.2 on, with those inside the heating bush 15 a laminar air flow during the melting process can be produced. The heating bush 15 also has heating elements 27 on which are operated electrically. The heating elements 27 are as heating coils around the bushing 28 arranged by which the in the 3 not shown preform 11 is feasible. By means of a diffuser designed as a quartz tube 29 becomes the heating coil 27 opposite the preform 11 covered. At the bottom 30 the heating bush 15 is an extension 31 arranged, which acts as a flow collar. With the extension 31 it is possible a predetermined temperature profile for the cooling process of the glass fibers 5 to reach after melting. The extension 31 can be made in one piece with the quartz glass. As appropriate, it has a separate copper bushing as an extension 31 proved.

In 4 is the heating bush 15 with an imported preform 11 shown. The preform 11 has a jacket tube 32 and a core bar 33 on. The preform 11 will be at the top 25 in the heating bush 15 introduced.

Through the flow panels 26.1 . 26.2 , which in the upper opening of the Heizbuchse 15 around the preform 11 are inserted, is between the inner flow aperture 26.1 and the preform 11 an annular gap 34 educated. Otherwise, the opening is through the flow panels 26.1 . 26.2 covered. The through the heating coils 27 heated air thus flows along the preform 11 in the direction of arrow B, C upwards from the heating bush 15 out. Through the flow panels 26.1 . 26.2 is achieved that the air flow remains laminar, which means that the air flow no undesirable cooling effects occur or turbulence within the Heizbuchse 15 be generated. However, the temperature profile can be inside the heating bushing 15 to be changed. Where the between the outer flow aperture 26.2 and the preform 11 resulting annular gap 34 is changeable, for example by the inner flow diaphragm 26.1 Will get removed. This ensures that the annular gap is larger. This causes more air at the preform 11 passed and thus a larger amount of heat from the Heizbuchse 15 is removed, which is then no longer available to the melting process.

It is for setting a temperature profile inside the heating bush 15 provided to use additional cooling elements, by means of which heat the heating coils 27 controlled is discharged. The cooling elements may be made of metal, preferably of copper in the heating coils 27 be embedded in supporting material. The cooling elements are otherwise in the 4 not shown.

From the heating bush 15 The glass is in the form of a fiber cladding and a fiber core having fiberglass 5 pulled and by the extension 31 led where the fiberglass 5 already cooled in a predetermined manner. By means of the length of the extension 31 can be set a targeted temperature profile for the cooling process. It is also possible by special measures for the ventilation of the extension 31 or by an arrangement or geometry of the extension 31 a predetermined temperature profile for the cooling process of the glass fiber 5 adjust. It is achieved in an advantageous manner that by the extension 31 a certain air flow on the glass fiber 5 is produced.

1

contraption

2

fiber furnace

3

drawing and coating plant

4

configurator

5

glass fiber

6

fiber bundles

7

up reel

8th

cooling section

9

funnel

10

flow collar

11

preform

12

tracking device

13

carrying disc

14

guide

15

Welding tool

16

Beschlichtungsanlage

17

drawing plant

13

pulling wheel

19

supporting role

20.1

simple roll

20.2

simple roll

21

reservoir

22

matrix

23

array axis

24

array axis

25

upper The End

26.1

flow screen

26.2

flow screen

27

heating element

23

execution

29

diffuser

30

lower The End

31

renewal

32

casing pipe

33

core rod

34

annular gap

α

angle

Claims (7)

Heating bush ( 15 ) for use in a fiber furnace ( 2 ) for producing optical glass fibers ( 5 ) from preforms ( 11 ), in particular of multicomponent glass fibers, characterized in that the fiber furnace ( 2 ) has a temperature control and that the temperature control comprises individual controls of the Heizbuchseninnentemperatur. Heating bush ( 15 ) according to claim 1, characterized in that the individual regulations measuring and compensating means for tuning the temperatures of the heating bushes ( 15 ) relative to adjacent Heizbuchsen ( 15 ) exhibit. Heating bush ( 15 ) according to one of claims 1 or 2, characterized in that the Heizbuchse ( 15 ) at least one heating element ( 27 ), preferably a plurality of separately controllable heating coils, and that between the heating element ( 27 ) and the preform ( 11 ) at least one diffuser ( 29 ) is arranged to scatter the heating radiation. Heating bush ( 15 ) according to one or more of claims 1 to 3, characterized in that the diffuser ( 29 ) preferably comprises a quartz tube and that the preform ( 11 ) of a tracking device ( 12 ) Is feasible through the quartz tube. Heating bush ( 15 ) according to one or more of claims 1 to 4, characterized in that each Heizbuchse ( 15 ) Fluid ( 26 ) for generating a laminar flow of air in the Heizbuchse ( 15 ) having. Heating bush ( 15 ) according to claim 5, characterized in that the fluid ( 26 ) one preferably integral with the diffuser ( 29 ) connected in the lower part of the Heizbuchse ( 15 ) extension ( 31 ), which are free of heating elements ( 27 ). Heating bush ( 15 ) according to one or more of claims 5 or 6, characterized in that the fluid ( 26 ) at least one flow aperture ( 26.1 . 26.2 ) at the upper end of the heating bushes ( 15 ), which for the air outlet an annular gap ( 34 ) with predetermined gap width around the preforms ( 11 ) guaranteed.