KR102018921B1

KR102018921B1 - mica tape and fire resistant cable including the same

Info

Publication number: KR102018921B1
Application number: KR1020130007489A
Authority: KR
Inventors: 손순일; 양훈철; 정승
Original assignee: 엘에스전선 주식회사
Priority date: 2013-01-23
Filing date: 2013-01-23
Publication date: 2019-09-05
Also published as: KR20140094883A

Abstract

A mica tape and a fire resistant cable comprising the same are disclosed. According to the mica tape and the fireproof cable including the same, it is possible to prevent the mica layer breakage of the mica tape to maintain the fire resistance performance and the electrical performance of the fireproof cable, and to ensure the reliability of the product, and the glass fiber of the mica tape. By improving the loosening phenomenon, it is possible to secure the structural stability of mycat tape. In addition, the homogeneity of insulator extrusion can be ensured in the fire resistant cable to which mica tape is applied.

Description

Mica tape and fire resistant cable including the same}

The present invention relates to a mica tape and a fireproof cable including the same, to prevent mica breakage and unwinding of glass mica of the mica tape applied to the fireproof cable, and to improve the electrical properties and fire resistance, including a mica tape and the same. It is about fireproof cable.

In recent years, a major issue in the cable manufacturing industry has been to improve cable behavior and performance in extreme temperature conditions, particularly in the event of fire. For safety, it is essential to delay the spread of flames and to maximize the cable's ability to withstand flames.

Increasing the fire-resistance of the cable will allow the cable to continue to operate in the event of a fire, and by delaying the spread of flames, it will provide the time needed to evacuate people or to deploy appropriate fire extinguishing means. Can be.

The level of demand for fire resistance is gradually increasing. In particular, cable products used in land and offshore plants and building infrastructure require higher fire resistance. Fire-fighting cables are needed to maintain the emergency power supply of core facilities, fire alarms, sprinklers, etc. for a minimum amount of time to escape and evacuate personnel in the event of a fire in a plant or building.

This fireproof cable exhibits fireproof performance by applying a fireproof layer inside the cable, and the fireproof layer winds up the mica tape having high heat resistance to maintain the function of the cable for a certain time even at a high temperature of 700 to 800 ° C. To help. At this time, the mica tape is manufactured by adhering the mica powder to glass cloth or PE tape, and in case of fire, even the insulator covers the conductor, thus replacing the role of the insulator.

In particular, in recent years, a mica tape is laminated on a glass fiber base layer, and a mica powder is coated on the base layer, and thus, mica tapes having improved fire resistance to withstand two hours or more at a temperature of about 900 ° C. have been used.

When the mica tape of the above structure is applied to a low pressure fireproof cable, the mica tape is wound on the conductor to ensure fire resistance. At this time, there is no problem in satisfying the fire resistance performance of the international standard for a conductor size product of 16 SQ or more.

However, when the mica tape is applied to a conductor of less than 16 SQ, the radius of curvature of the mica tape is reduced because the conductor diameter is small, and thus the mica layer is broken or the glass fiber to be insulated during taping to form a fireproof layer. While the adhered mica powder is dropped by friction, at the same time, it promotes the unwinding of the glass fiber, which has the disadvantage of lowering fire resistance.

Furthermore, there is a problem that causes a problem in the homogeneity of the insulator extrusion due to the phenomenon that the glass fiber ol is caught on the insulating dice when the insulator is formed due to this loosening.

Therefore, there is a need for a mica tape that can solve the above problems, prevent mica breakage and loosening of glass fibers, and improve electrical properties and fire resistance.

Embodiments of the present invention to prevent the mica layer breakage of the mica tape to maintain the fire resistance and electrical performance of the fire-resistant cable, to ensure the reliability of the product.

In addition, to improve the glass fiber loosening phenomenon of the mica tape to secure the structural stability of the mica tape.

In addition, to ensure homogeneity of insulator extrusion in a fire resistant cable to which mica tape is applied.

According to an aspect of the present invention includes a base layer made of glass fibers and a mica layer made of MICA (MICA) laminated on the base layer, the weave density of the glass fiber is characterized in that made of 35% to 50% Mycat tape can be provided.

The mica density of the mica layer may be made of 140 g / m² to 170 g / m².

The mica tape according to the present invention may further include a mica powder coating part provided in the base layer.

According to another aspect of the present invention, it comprises a base layer made of glass fibers, and a mica layer made of mica (MICA) laminated on the base layer, the mica density of the mica layer is 140g / m² to 170g / m² The mica tape may be provided.

According to another aspect of the present invention, a conductor and a fireproof layer for performing the conductor protection and insulation function in case of fire, the fireproof layer is a base layer made of glass fibers of 35% to 50%, A fire resistant cable comprising a mica layer made of mica (MICA) stacked on the base layer may be provided.

Here, the fire resistant cable according to the present invention may further include an insulating layer formed outside the fire resistant layer, and the fire resistant layer may be formed directly on the conductor.

The fire resistant cable according to the present invention includes a first semiconducting layer formed outside the conductor, an insulating layer formed outside the first semiconducting layer, a second semiconducting layer formed outside the insulating layer, and the second The semiconductor device may further include a shielding layer formed outside the semiconductive layer, and the fireproof layer may be formed between the insulating layer and the second semiconducting layer.

In addition, the fire resistant cable according to the present invention may further include a second insulating layer provided between the fire resistant layer and the second semiconducting layer.

Embodiments of the present invention can prevent the mica layer breakage of the mica tape to maintain the fire resistance and electrical performance of the fire-resistant cable, and to ensure the reliability of the product.

In addition, it is possible to secure the structural stability of the mycat tape by improving the glass fiber loosening phenomenon of the mycat tape.

In addition, the homogeneity of insulator extrusion can be ensured in the fire resistant cable to which mica tape is applied.

1 is a cross-sectional view showing the structure of the mica tape according to an embodiment of the present invention
Figure 2 is a planar image and configuration diagram showing a glass fiber woven structure of mica tapes according to an embodiment of the present invention
Figure 3 is a cross-sectional view showing a case where the mica powder coating portion is applied to the glass fiber of mica tape according to an embodiment of the present invention
4 is a cross-sectional view of a single-phase low pressure fireproof cable according to an embodiment of the present invention.
Figure 5 is a cross-sectional view of the three-phase low pressure fireproof cable according to an embodiment of the present invention
6 is a cross-sectional view of a single-phase high-pressure fireproof cable according to an embodiment of the present invention.
7 is a cross-sectional view of the three-phase high-pressure fireproof cable according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed contents can be thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art. Like numbers refer to like elements throughout.

1 is a cross-sectional view showing the structure of the mica tape according to an embodiment of the present invention, Figure 2 is a planar image and configuration diagram showing a glass fiber weave structure of the mica tape according to an embodiment of the present invention, 3 is a cross-sectional view illustrating a case in which the mica powder coating part is applied to the glass fiber of the mica tape according to an embodiment of the present invention.

1 to 3, the mica tape 30 according to an embodiment of the present invention includes a base layer 31 made of glass fiber and a mica (MICA) stacked on the base layer 31. It includes a mica layer 33, the weave density of the glass fiber may be made of 35% to 50%.

Specifically, the mica layer 33 of the mica tape 30 may be made of a soft mica material, and the glass fibers forming the base layer 31 under the mica layer 33 may be formed of a mica using a silicone-based resin. Can be adhered to layer 33.

Here, the silicone-based resin may include additives such as Benzyl Alcohol, Ethane, Hexa Chloro, 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-28-done, etc. have.

The glass fiber plays a role of maintaining mechanical properties at high temperature. Such a glass fiber fabric made of glass fiber has a width of 200 to 500 μm and a length of 100 to 300 μm for the glass yarn 31a having a thickness of 80 to 120 μm. It has a woven form to be formed.

The weight density of the glass yarn (31a) may be made of 20 ~ 26g / m² level. The mica powder coating part 31b is applied to the empty space of the glass yarn fabric to reinforce the electrical properties, wherein the mica powder used for the mica powder coating part 31b is made of soft mica, hard mica, or soft / hard mica. It may consist of a mixture.

On the other hand, the weaving density of the glass yarn fabric applied to the mica tape 30 according to the present invention is preferably made of 35% to 50%. Here, the weave density (ρ) of the glass yarn fabric refers to the area ratio occupied by the glass yarn 31a in the entire tape area, and can be expressed by the following formula.

ρ (%) = 100 × {A × B-(A-D) × (B-D)} / (A × B)

Here, A corresponds to the horizontal spacing of the unit area constituting the glass yarn fabric, as shown in Figure 2 (b), B corresponds to the vertical spacing of the unit area constituting the glass yarn fabric, D is the Corresponds to the thickness.

Therefore, by appropriately changing the values of A, B, and D, the weaving density of the glass yarn fabric can be adjusted to fall within the range of 35% to 50%.

If the weaving density of the glass yarn fabric is less than 35%, the mica layer 33 and the base layer 31 made of glass fiber have a small adhesion area, so that the mica falls when taping on a conductor having a small outer diameter of less than 16 SQ. Then, the glass yarns 31a at the edges of the tape may come off from the mica layer 33 and may loosen.

Meanwhile, in order to reinforce the electrical properties, the mica powder coating part 31b is formed by additionally coating the mica powder in the empty space not occupied by the glass yarn 31a toward the glass yarn fabric, and the woven density is 50% or more. If too high, the area of the area other than the glass yarn 31a is narrowed so that the area to which the mica powder is coated is reduced, so that the reinforcing effect of the electrical properties is lowered and the fire resistance of the cable is lowered. have.

Therefore, the above-described problem can be solved by manufacturing the mica tape 30 according to the exemplary embodiment of the present invention, which has a glass yarn woven density of 35% to 50% of the base layer 31 made of glass fibers.

Looking at the specific effects of the present invention through the experimental results are as follows.

TABLE 1

Table 1 shows the results of evaluating the fabrication and fire resistance performance of fire resistant cable products with glass fabrics of different weave density. In case 1 and 2 of less than 35% of the weaving density, there was a problem that the mica layer 33 partially fell off the glass yarn fabric and the glass yarn 31a fell out during the taping operation of the mica tape 30. The test also failed to pass all specifications.

In case 5, where weaving density is higher than 50%, there was no problem of falling mica and missing glass yarn, but it was found that fire resistance performance was lower than Case 3 or Case 4 because only part of the fire resistance test passed.

On the other hand, the selection of the mica density of the mica layer 33 that influences the electrical insulation properties as well as the weave density of the glass yarn fabric to maintain the mechanical properties at high temperature is also an important factor in ensuring the fire resistance performance of the cable.

The thicker the mica layer 33, that is, the higher the mica density, the better the insulation performance at high temperature. When the amount of mica per unit area increases beyond 170 g / m², the mica layer 33 becomes too thick to tape the conductor. It tends to crack and break easily, which can lead to a problem of poor fire performance.

On the other hand, if the mica density of the mica layer 33 is too low, less than 140 g / m², the electrical insulation performance at high temperature is lowered, so the 750 ° C general fireproof standard IEC 60331-21 standard is passed, but 830 ° C and 950 ° C The test of high fire resistance standards fails.

Therefore, the mica density of the mica layer 33 is preferably made of 140 g / m² to 170 g / m², and the results are as follows.

TABLE 2

Table 2 shows the results of evaluating the fire resistance performance of the prototype of the fire resistant cable in which the mica density of the mica layer 33, that is, the mica tapes 30 having different mica weights per unit area is applied.

Specifically, in case 1 where the mica layer 33 has a mica density of 130 g / m², the fire resistance performance of the fire resistant cable is low, and thus the fire resistance test of IEC 60331-21 (750 ° C., general fire resistance 90 minutes) passes, but the temperature The fire resistance test of IEC 60331-1,2, BS 6387, BS 8491, etc., with high standards of 830 ° C and 950 ° C, as well as fire and spray conditions, was not passed.

In addition, in case 3 where the mica density of the mica layer 33 is high as 180g / m², the amount of mica is too large, and thus the adhesion between the mica powder is relatively low, and cracking or fracture occurs when taping on the conductor, and finally, mica tape ( 30) did not serve to maintain electrical insulation at high temperatures and did not pass most fire test specifications.

As shown in the experimental results of Table 1 and Table 2, when the mica density of the mica layer 33 is maintained at 140 to 170 g / m² and the weaving density of the glass yarn is maintained at a level of 35 to 50%, There is no other problem, and it can be seen that it is possible to manufacture fireproof cable products satisfying the fire resistance performance of various international standards.

In conclusion, when manufacturing a fireproof cable using the mica tape 30 according to an embodiment of the present invention, such as the loosening of the glass yarn 31a or the crushing of the mica layer 33, which has been a problem in the existing products. No problem occurs, and the required fire resistance and electrical properties can be maintained.

In addition, in the case of the fireproof cable product of the invention using the mica tape 30, IEC 60331-1,2, BS 6387 Cat. It can meet the fire resistance test of various international standards such as C / W / Z, BS EN 50200, BS 8481.

Hereinafter, the structure of the fire resistant cable to which the mycat tape 30 according to the present invention is applied will be described in detail.

4 is a cross-sectional view of a single-phase low pressure fireproof cable according to an embodiment of the present invention, Figure 5 is a cross-sectional view of a three-phase low pressure fireproof cable according to an embodiment of the present invention.

1 to 5, a fireproof cable 100 according to an embodiment of the present invention includes a conductor 111 and a fireproof layer 114 for protecting and insulating the conductor 111 in a fire. The fire resistant layer 114 is a mica layer 33 composed of a base layer 31 having a woven density of glass fiber of 35% to 50%, and a mica (MICA) stacked on the base layer 31. It may be made, including.

The conductor 111 may be a Class 2 or Class 5 conductor that satisfies the IEC 60228 standard.

Meanwhile, an insulating layer 113 made of an insulator may be provided to insulate the conductor 111.

The insulating layer 113 is made of a material having insulating and impact resistance characteristics, and serves to cover and protect the conductor 111 and to insulate the conductor and the outside from inside to prevent current from flowing out of the cable. Here, the insulating layer 113 is made of silicon rubber, cross-linked polyethylene (XLPE), cross-linked polyollefin (XLPO), ethylene-propylene rubber (EPR), high strength ethylene It may be made of polymers such as high ethylene-propylene rubber (HEPR), polyvinyl chloride (PVC), and mixtures thereof.

The fireproof layer 114 includes a base layer 31 composed of 35% to 50% woven density of glass fibers, and a mica layer 33 made of mica (MICA) stacked on the base layer 31. The mica tape 30 can be made by winding one or two or more layers.

And as described above, the mica density of the mica layer 33 is preferably made of 140g / m² to 170g / m².

The fireproof layer 114 may be formed directly on the conductor 111. The fire resistant cable 100 shown in FIG. 4 is used for a low voltage of 3 kV or less, satisfies electrical characteristics by only one layer of insulation on the conductor 111, and places the fire resistant layer 114 directly on the conductor 111. Even if formed, the fire resistance performance and electrical characteristics of the cable can be exhibited without the problem of partial discharge or dielectric breakdown.

Here, the conductor 111, the fireproof layer 114, and the insulating layer 113 constitute a cable core 110.

An inner sheath layer 120 may be formed outside the cable core 110. The inner sheath layer 120 may include polyvinyl chloride (PVC) and polychloroprene rubber having high impact resistance; CR), chlorosulfonated polyethylene (CSPE), chlorinated polyethylene (CPE), ethylene vinyl acetate (ethylene vinyl acetate; EVA), or a mixture of these may be applied in the form of an extruded layer.

An outer layer 130 is formed outside the inner sheath layer 120. The outer layer 130 is made of a metal material such as copper, aluminum, iron, a copper alloy, an aluminum alloy, metal braided metal tape, metal, and the like. It may be made in the form of a wire.

In addition, an outer sheath layer 140 is formed outside the outer layer 130, and the outer sheath layer 140, like the inner sheath layer 120, has a high impact resistance polyvinyl chloride (PVC). , Polychloroprene rubber (CR), chlorosulfonated polyethylene (CSPE), chlorinated polyethylene (CPE), ethylene vinyl acetate (EVA) or mixtures thereof It is in the form of an extruded layer and serves to protect the cable from external impact or corrosion.

The structure of the inner sheath layer 120, the outer layer 130, and the outer sheath layer 140 may vary depending on the purpose of the cable.

Meanwhile, the low voltage fireproof cable 100 may be formed of a single core product consisting of one cable core 110 as shown in FIG. 4 or a multicore product consisting of two or more cores as shown in FIG. 5. .

In the case of a multi-core product, several cable cores 110 are collected and fed together at a predetermined pitch, and then the filler 150 is applied to the voids, and then the inner sheath layer 120, the outer layer 130, and the outer sheath layer are described above. 140 may be formed to complete the product. The low-pressure fireproof cable 100 shown in FIG. 5 is a three-phase cable and shows a case in which three cable cores 110 are formed.

6 is a cross-sectional view of a single-phase high-pressure fireproof cable according to an embodiment of the present invention, Figure 7 is a cross-sectional view of a three-phase high-pressure fireproof cable according to an embodiment of the present invention.

1 to 3, 6, and 7, a fire resistant cable according to an embodiment of the present invention includes a conductor 111 and a first semiconducting layer 112 formed outside the conductor 111. And an insulating layer 113 formed outside the first semiconducting layer 112, a second semiconducting layer 115 formed outside the insulating layer 113, and an outer side of the second semiconducting layer 115. And a fireproof layer 114 provided between the shielding layer 116 and the insulating layer 113 and the second semiconducting layer 115.

The fireproof cable proposed in this embodiment corresponds to a fireproof cable for medium pressure or high pressure.

The conductor 111 may be a Class 2 or Class 5 conductor that satisfies the IEC 60228 standard. The first semiconducting layer 112 formed on the outer side of the conductor 111 may be formed by winding a semiconducting compound by extrusion or semiconducting tape, and applying them simultaneously to form a composite layer.

The first semiconducting layer 112 is an internal semiconducting, which uniforms the distribution of charges on the surface of the conductor to alleviate the electric field concentration inside the cable, and fills the gap between the conductor and the insulator to minimize insulation deterioration due to ionization. Can play a role.

The insulating layer 113 is made of a material having insulating and impact resistance characteristics, and serves to cover and protect the conductor 111 and to insulate the conductor and the outside from inside to prevent current from flowing out of the cable. Here, the insulating layer 113 is made of silicon rubber, cross-linked polyethylene (XLPE), cross-linked polyollefin (XLPO), ethylene-propylene rubber (EPR), high density ethylene It may be made of polymers such as high ethylene-propylene rubber (EPR), polyvinyl chloride (PVC), and mixtures thereof.

The second semiconducting layer 115 formed outside the insulating layer 113 is an external semiconducting, similarly to the internal semiconducting, a semiconducting compound is formed by winding an extruded or semiconductive tape and simultaneously applying them to form a composite layer. It is also possible.

The second semiconducting layer 115 serves to equalize electrical stress in the insulator and minimize external corona.

The shielding layer 116 is applied to a material such as copper, aluminum and copper alloys, aluminum alloys and may be in the form of metal tape or metal braided. The shielding layer 116 should be in contact with the second semiconducting layer 115, which is because if the shielding layer 116 and the second semiconducting layer 115 are not in contact with each other, the grounding should be performed separately. Because.

The fireproof layer 114 includes a base layer 31 composed of 35% to 50% woven density of glass fibers, and a mica layer 33 made of mica (MICA) stacked on the base layer 31. The mica tape 30 can be made by winding one or two or more layers. And as described above, the mica density of the mica layer 33 is preferably made of 140g / m² to 170g / m².

In this case, the number of windings may vary depending on the required fire resistance performance, cable structure, and use. That is, the fireproof layer 114 may be formed by winding once or by winding two or more times to form the fireproof layer 114.

Meanwhile, in the medium or high pressure fireproof cable according to an embodiment of the present invention, the fireproof layer 114 is provided between the insulating layer 113 and the second semiconducting layer 115, but is not limited thereto. It is also possible to form the fireproof layer 114 in another part as needed.

As such, the medium or high pressure fireproof cable 100 according to an embodiment of the present invention may include a conductor 111, a first semiconducting layer 112, an insulating layer 113, a fireproof layer 114, and a second peninsula. The cable core 110 is configured based on the front layer 115 and the shielding layer 116, and the fireproof cable 100 for medium pressure or high pressure may be completed by performing sheathing and sheathing on the outside of the cable core 110. have.

Specifically, the inner sheath layer 120 may be formed outside the cable core 110. The inner sheath layer 120 may have high impact resistance, polyvinyl chloride (PVC), polychloroprene rubber ( polychloroprene rubber (CR), chlorosulfonated polyethylene (CSPE), chlorinated polyethylene (CPE), ethylene vinyl acetate (EVA) or mixtures thereof. Can be.

On the other hand, the medium or high pressure fire-resistant cable 100 is a single core product consisting of one cable core 110 as shown in Figure 6 or a multi-core product consisting of two or more cores as shown in Figure 7 Can be done.

In the case of a multi-core product, several cable cores 110 are collected and fed together at a predetermined pitch, and then the filler 150 is applied to the voids, and then the inner sheath layer 120, the outer layer 130, and the outer sheath layer are described above. 140 may be formed to complete the product. The medium voltage or high pressure fireproof cable 100 shown in FIG. 7 is a three-phase cable and shows an example in which three cable cores 110 are formed.

As described so far, according to the mica tape and the fire resistant cable including the same, the mica layer of the mica tape can be prevented from being damaged to maintain the fire resistance performance and the electrical performance of the fire resistant cable, and the reliability of the product can be ensured. In addition, it is possible to secure the structural stability of the mycat tape by improving the glass fiber loosening phenomenon of the mycat tape.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to various modifications and changes to the present invention without departing from the spirit and scope of the invention described in the claims described below You can do it. Therefore, it should be seen that all modifications included in the technical scope of the present invention are basically included in the scope of the claims of the present invention.

30: mica tape 31: base layer
33: mica floor

Claims

Conductor; And
It includes a fireproof layer that performs the conductor protection and insulation function in case of fire,
The fire resistant layer is formed from mica tape,
The mica tape is a base layer made of glass fiber woven glass fiber; A mica layer made of mica stacked on the base layer; And a mica powder coating portion formed in the empty space of the glass yarn fabric,
Weave density of the glass fiber is made of 35% to 50%,
The mica density of the mica layer is 140g / m² to 170g / m²,
Fire-resistant cable characterized by passing the fire resistance test according to the standard IEC 60331-1,2, BS6387 and BS8491.

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The method of claim 1,
And an insulation layer formed outside the fireproof layer, wherein the fireproof layer is formed directly on the conductor.

The method of claim 1,
A first semiconducting layer formed outside the conductor,
An insulating layer formed outside the first semiconducting layer,
A second semiconducting layer formed outside the insulating layer,
Further comprising a shielding layer formed on the outside of the second semiconducting layer,
And the fireproof layer is formed between the insulating layer and the second semiconducting layer.

The method of claim 7, wherein
And a second insulating layer provided between the fireproof layer and the second semiconducting layer.

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