DE2607665A1 - METHOD OF SPINNING GLASS FIBER - Google Patents

Description

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Miitto BosekICo. Ltd., Fukushiiaa / Japan

Process for spinning glass fibers

The present invention relates to a method of spinning from fiberglass- In particular, the invention relates to an improved one Yerfahren for spinning vchi using glass fibers a flat nozzle plate with a large number of openings per unit area made from a material which almost no wetting is exhibited by molten glass-

Bisker have been designing various apparatus for the production of glass fibers. A typical example of such apparatus is a spinning furnace with a flat multi-hole nozzle made of platinum-coated metal. This MehrlocäidSse is a flat plate of a platinum-Bhodinm-Legierong of simple constructions, ie it has a few openings of 1.5 to 3 mm diameter. However, this platinum-shodium alloy has

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the disadvantage that the contact angle to the molten Glass is very small, i.e. the wetting with molten glass is very large. A multi-hole nozzle a platinum-gold-rhodium alloy, which was later developed, has a larger contact angle to the molten one Glass as a platinum-rhodium alloy.-Multi-hole nozzle, so that thus the wetting with molten glass is not so great. However, it is when using the platinum-rhodium alloy as well as when using the platinum-gold-rhodium alloy inevitable that - if the distances between each Openings become smaller for molten glass beads at the exit end of the openings are formed and spread to a large extent Spread over the surface of the opening as soon as one of the threads running through an opening is cut, so that other threads, which run through the neighboring openings, also be cut through. This phenomenon would gradually progress until all the threads are cut and the lower surface of the multi-hole nozzle is covered with the molten glass flowing out of the openings. As soon as such Phenomenon occurs, it is very difficult to achieve a separation into single threads, i.e. to restore the state in which molten glass flowing through an opening has an independent stream of thread forms without uniting with other molten glass flowing through another opening. In particular, if the distances between the individual openings are less than 5 rom, it is completely out of the question, even for experts, a separation into individual threads to achieve individual, independent To form streams from each opening of the nozzles according to known methods.

In order to improve the above-mentioned shortcomings, a method

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developed using chip nozzles. Since the area covered with molten glass from a If such a nozzle is limited to the lowest part of a splinter, the molten glass emerging from a nozzle becomes after this process forced to form an independent or single stream without interfering with the molten Connect glass from other nozzles. Because of this, the threading can be easily done by yourself when the nozzles are placed close to each other. It is thus also possible to have a larger number of nozzles per unit area than to be arranged with the flat multi-hole nozzles mentioned above and thereby noticeably increase productivity. On the other hand, this split spinneret has the following disadvantages. The side wall of each split nozzle requires a certain amount Thick and thereby concave parts arise in the splinters or shavings (chips); if then a splinter is very close to the other If the splinter is placed, the molten glass would penetrate into the concave parts and have an adverse influence take on the effect of the split nozzles. Also about productivity To increase it, it is necessary to place cooling devices in places between the two chips. The above The reasons mentioned make it necessary to limit the number of nozzles per unit area. If too many split nozzles are present in the nozzle plate, the shape of the nozzle plate should be enlarged; about 2,000 holes appear at the practical to be the upper limit of the number of nozzles in the plate because of the deformation of the plate. There In addition, the nozzle plate is made of an expensive platinum-rhodium or platinum-gold-rhodium alloy, with The amount of precious metals used can increase with the number of nozzles, which means the investment and Expenditures for the product to be manufactured increased.

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Further methods are, for example, in the publication by K.L. Leowenstein the Manufactural Technology of Continuous Glass Fibers "Elserier Scientific Publication Co., New York 1973, but these methods are in those noted above Insufficient points.

It is an object of the present invention to provide an improved method for constantly spinning glass fibers with excellent To create productivity in which a special nozzle plate with a large number of openings per unit area is used, in which the respective ends of the monofilaments can be easily found, and in which the Disadvantages of known methods are avoided.

The above-mentioned aim is achieved according to the invention in that a method for spinning glass fibers is created, in which single threads are drawn from each opening of a nozzle plate connected to a melting furnace, in which a nozzle plate made of a material having a contact angle of 60 ° or more with the molten glass is used which has a large number of openings per unit area, so that the molten glass flow out of the openings can form coherent pearls that are connected or combined molten glass beads are gradually drawn onto the lower surface of the nozzle plate, so that the molten Glass is separated into filaments from each of the openings and the ends of the filaments are easily found can.

Since in the method according to the invention a special nozzle plate with a large number of openings per unit area is used is the productivity of the nozzle plate

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per unit area about 1ο to 8o times as high as one Plate in a known process, and constant or uniform glass fibers can be continuously produced - in contrast to known procedures.

In the method according to the invention, glass is made in a known manner Melting furnace, such as a port furnace (bushing), a tank furnace or the like, melted down. On the ground A special flat spinning iron plate is placed in the port furnace. The. Spinneret must be made of a material which has a contact angle of 60 ° or more, preferably 90 ° or more, to the molten glass.

The contact angle of the material with the molten glass is measured as follows. A small glass bead (0.1 to 0.2 g) is made placed on a flat plate made of the material to be tested; after that the plates and the glass bead placed in an oven - with the plate placed horizontally - and there for 1 hour at constant temperature, i. held at 1100 to 1200 ° C. Then they are taken out and frightened with air and on the cold stone. They are then photographed from an exactly lateral direction. then becomes the contact angle using a known method measured. It is known that the contact angle measured by this quenching method is the contact angle at high Temperatures almost the same.

In the present invention, when the contact angle with the molten glass is 90 ° or more, the material is defined as having a non-wetting property; When ¹ the contact angle is 6o or more and less than 9o °, the material has poor wetting property.

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The materials having a contact angle of 90 ° or more with the molten glass are particularly preferred materials for making nozzle plates for the present invention. Examples of such materials are graphite (15ο ^0,! Measured at 11oo ° C), boron nitride (13o °, measured at 11oo ° C), and the like. The materials which have a contact angle of 60 ° or greater and less than 90 ° with the molten glass can be used to make satisfactory spinneret plates when process conditions are changed. Examples of such materials are a platinum-rhodium-gold alloy, a gold-palladium alloy, and the like.

The flat spinneret plate made from such materials as described above has a large size Number of openings per unit area, so that the outflow of molten glass from the openings is contiguous or combined molten glass beads can form. The distances between the individual openings in such a plate are 5 mm or less, preferably from 0.5 to 2.5 mm. Since the diameter of an opening is generally from 0.3 to 2, ο mm, the number of openings per area

2 is preferably 25 to 200 per cm in the spinneret plate.

Since the number of openings per unit area in a known, flat spinneret plate made from a platinum-rhodium

2 alloy was made, is about 2.4 per cm, but

the value of 25 to 2oo openings per cm means 10 to 8o times the known value. But that means that the The yield of glass fibers per unit area of the spinneret plate can be increased up to 10 to 80 times according to the invention Method compared with a known method.

The inventive method using such

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special spinneret plate is described in more detail below.

The combination of two or more streams from out openings The molten glass flowing out of the spinneret is generally due to the wetting property between the molten glass and the spinneret plate, i.e. each molten glass flowing out of an opening in the plate Glass stream spreads outward from the periphery of the opening to connect with other streams. To now to avoid the combination of one or more streams of molten glass at the lower surface of the spinneret plate, it was previously necessary to keep a noticeable distance between two or more openings so that none the molten glass beads, which are formed when the molten glass flows naturally from an opening, be combined. But even if the above conditions were met satisfactorily, so far it has been Impossible even for a person skilled in the art to separate the combined, molten glass beads into independent streams of To separate individual threads from the individual openings and to find the end of the individual threads, provided known spinning processes were used, in which single threads were drawn from individual openings of the spinneret.

In contrast, according to the invention, the combined molten glass beads are easily separated into individual threads and äs the end of the individual threads can be easily found in each case, as the material of the spinning nozzle plate is made of a material with non-wetting or hardly wetting property, and since the combined molten glass beads are gradually drawn from the lower surface of the spinneret plate

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will.

When spinning glass fibers using a spinneret plate from a material with a contact angle of 9o ■ or more to the molten glass, i.e. from a material with no wetting property and provided that the distances between each opening are 5 mm or less, the following procedure can be used. Since the number of openings per unit area is very large, and there is molten Glass slightly wets itself, every molten glass bead that flows out of the openings spreads, on the lower surface of the spinneret plate and merges with the others, so that the whole area of the Surface is covered. Since the spinneret plate has a non-wetting property compared to molten glass, the molten glass, which has spread over the whole surface of the spinneret plate, becomes every periphery of the opening retracted and thus easily divided into filaments when the molten glass covering the lower surface the plate covered, with increasing viscosity at a rate greater than the rate of outflow of the molten material Glass is pulled down from the furnace. The greater the viscosity of the molten glass, the lower the The surface of the spinneret plate is covered, the easier the separation into individual threads can take place because of the rise the amount of molten glass that is pulled down, and because of the influence - the pulling force. on this way the end of each thread can be easily found.

When glass fibers using a spinneret plate made of a material with a contact angle of 60 to 9o ° to the molten

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Glass, ie material with low wetting properties, are spun, and if the distances between each opening are 5 mm or less, the separation of the combined, molten glass beads into individual threads can easily be carried out in the same manner as described above, ie when the molten glass which has flowed out of the orifices and which covers the lower surface of the high viscosity spinneret plate is gradually pulled down so that it comes off the surface. If the separation into individual threads is insufficient, a ^Λ . A stream of air is blown onto the combined molten glass beads covering the lower surface of the spinneret plate to cool them down and increase the viscosity of the molten glass. In this way, the end of each thread can be easily found. When the separation into individual threads has been achieved and the threads can be constantly wound up, the blowing in of air is stopped. If the tensile force effectively influences the periphery of the openings, the influence of the surface tension for cutting off the threads and for producing the glass beads decreases; and the stability of the miniscus formed under the openings can be kept in good condition.

A spinneret plate made of graphite or boron nitride is and can be far superior to known plates in terms of wettability can be easily used for spinning glass fibers to make excellent products. One Spinneret plate made of a platinum-rhodium-gold alloy with a contact angle of 60 ° or more to the molten glass exhibits excellent properties in terms of strength, durability, oxidation resistance and the like, and can be used for constant spinning of fiberglass over a long period

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Can be used over a period of time. On the other hand is a spinneret plate made of graphite or boron nitride a plate made of the above alloy a little in terms of durability inferior, but since the former has non-wetting properties, it has many advantages such as ease of operation, low manufacturing cost, and the like.

The following examples further illustrate the present invention.

example 1

A nozzle plate made of graphite with 87 openings of 1.0 mm diameter - The number of openings was 29 per cm arranged at the bottom of a well-known port furnace (bushing). As a glass, Ε glass was used for spinning. From every opening molten glass flowed at a rate of 0.3 g / min. Every molten one that flows naturally from every opening Glass bead was combined with the others and then covered the lower surface of the nozzle plate while maintaining the viscosity of the glass rose. Then the molten glass covering the surface became faster than the flow rate of the molten glass pulled down from the furnace. The combined, melted glass beads were thus cut into individual threads; In addition, the respective end of the individual threads could easily be found in this way being found. The threads were wound up at a speed of 1,000 m / ml. Glass threads with a diameter of 13yU were obtained. The spinning temperature was 112o ° C. The contact angle between the molten glass and the graphite was 150 ° at 110 ° C.

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If a spinneret plate made of graphite with 400 orifices of 1, o mm diameter was used, whereby the number of open-

openings was 36 per cm, and if the same procedure as as described above was applied, glass filaments at a winding speed of 500 m / min were made of the same Preserved delicacy.

Example 2

When using a spinneret plate made of boron nitride instead of graphite and when the procedure described in Example 1 is repeated Procedure, the same results as in Example 1 were obtained. The contact angle between the molten Glass and the boron nitride was 130 ° at 111o ° C.

Example 3

There were spinneret plates made of a platinum-rhodium-gold alloy (Composition: Pt 85.5% by weight, Rh 9.5% by weight and Au 5% by weight) with openings 1.3 mm thick in diameter used, the number of openings exhibiting the values given in Table 1. Each spinneret plate was on the bottom of a known port furnace and the spinning of the glass fibers was carried out as in the method according to Example 1, where Ε-glass was used. Melt poured out of each opening Glass at a rate of about 0.6 g / min. Every molten glass bead that flows naturally from every opening was bonded together so that the combined beads covered the lower surface of the spinneret plate. then the molten glass covering the surface became at a faster rate than the flow rate of the molten glass pulled down from the openings. The combined, melted glass beads were broken into individual Threads unraveled, and the end of each thread could be

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easily found. The threads were wound up at speeds of 1,000 to 3,000 m / min, the precise values being given in Table 1. That way were
Glass threads with diameters from 6 to 1o, u get as it
shown in Table 1.

Table 1

Approach number of number of Aufwickel- Spinntem- fineness

Openings per speed (micron)

No.

openings

speed (m / min) (C)

1 I00 29 3,000 11 60 1o 2 4oo 36 3ooo 11 60 1o 3 800 45 2ooo 115o 8th 4th 2ooo 45 I000 114o 6th

The contact angle between the molten glass and the
The platinum-rhodium-gold alloy was 76 ° at 1200 ° C. When an air flow at a rate of 1o to 5o l / min
The combined molten glass beads covering the surface of the spinneret plate were blown in to cool while the ends of the individual threads were being found, the separation of the molten glass into individual threads emerging from the respective openings could be carried out more easily than when no air was blown in. The airflow
was blown in in the direction of the openings, so that in this way the minisks of the molten glass emerging from the openings could be effectively cooled. The air injection was stopped after a constant
The thread had started winding.

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Example 4

When using a spinneret plate made of a gold-palladium alloy (Composition: Au 80 wt% and Pd 2o wt%) were made glass fibers in the same manner as in Example 3, batch no. 1,2 and 3 described were spun. Almost the same results were obtained as in Example 3, batch No. 1, 2 and 3 received. However, since the heat resistance of the gold-palladium alloy is that of the platinum-rhodium-gold alloy, as used in Example 3, the former has a disadvantage in use. The contact angle between the molten glass and the gold-palladium

o _o
Alloy was 82 at 1200 C.

Comparative example

A platinum-rhodium alloy, as used on a large scale Used in the manufacture of spinneret plates, it has a contact angle to the molten glass of 32 ° at 12oo ° C. Under Using a spinneret plate made from the platinum-rhodium alloy was spinning glass fibers in the same way and Manner as described in Example 3, run no. 2 was tried. Because the platinum-rhodium alloy has wetting properties for the molten glass, it was very difficult to separate into filaments and to spin the Optical fibers could not be reached.

As can be clearly seen from the above examples, according to the invention it is not only possible to use glass fibers at constant Way to spin, but it is also possible to easily make very fine glass fibers,

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since finding the ends of the individual threads according to the The method of the present invention is simple. It is also possible, the production of the glass fibers around the Ιο- up It can be increased 80-fold compared to known processes if a spinneret plate of the same Äusmasse as it is in known processes Method is used, is applied. In addition, it is possible according to the invention, in a direct way, strands that consist of a remarkably increased number of single filaments are assembled without having to use the known method the chain tree (warp beaming), doubling and the like are necessary. According to the invention, glass fibers can be used in large Manufactured to a large extent and under economic conditions.

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Claims (7)

Claims 1. Method of spinning glass fibers by drawing of individual threads from each individual opening of a spinneret plate, which is attached to a melting furnace, characterized in that one has a spinneret plate made of a material having a contact angle of 60 or more with the molten glass, and the one has a large number of openings per unit area, so that the molten glass flowing out of the nozzles combined Beads can form, gradually pulling the combined, molten glass beads from the lower surface of the nozzle plate to form the molten glass in filaments emerge from each individual opening, separate and find the end of the individual threads. 2. The method according to claim 1, characterized in that the pulling speed for the combined, molten glass beads is greater than the outflow velocity of the molten glass from the furnace. 3 ο method according to claim 1, characterized in that a spinneret plate is used, made of a material having a contact angle of 90 ° or more with the molten glass. 4. The method according to claim 3, characterized in that a spinneret plate is used, made of graphite or boron nitride. 5. The method according to claim 1, characterized in that the spinneret plate 25 to 200 openings per cm. 7 0 9 8 3 5/0298 - _on , _{Q | NAL} INSPECTED 6. The method according to claim 1, characterized in that a spinneret plate is used, made of a material with a contact angle of 6o to 9o ° to the molten glass, and that there is a stream of air blows into the combined molten glass beads covering the lower surface of the spinneret plate, until the combined, molten glass beads are separated into individual threads, and the constant pulling of each one Threads is achieved. 709835/0298