KR20160097951A - Fire resistant cable and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to a fire resistant cable capable of reducing consumption and manufacturing costs of a mica tape while maintaining high fire resistance performance to pass a fire resistant hitting test or a spray test; and a manufacturing method thereof. According to the present invention, the fire resistant cable comprises: a conductive portion; a first mica tape which surrounds the conductive portion in a spiral shape, having an outer side coated with mica; a second mica tape which surrounds the first mica tape, having an inner side coated with mica, and coming in contact with the mica of the first mica tape; and includes an insulation layer formed outside the second mica tape. The manufacturing method comprises: a core wire forming method; a first tape forming step, a second tape forming step, and an insulation layer forming step. According to the configuration of the present invention, the mica tape is formed of only two layers, and is possible to reduce consumption and manufacturing costs of the mica tape while maintaining a high performance of fire resistance to pass the fire resistant hitting test or the spray test; a breaking phenomenon of the mica caused by a valley formed on an outer surface of the conductor is prevented at the time of the fire resistance test; the mica of the first mica tape and the mica of the second mica tape are lumped at high temperature and high pressure; damage of the mica becomes less as opposed to the breaking of the mica in case of fire; is possible to reduce overlap of the mica tape; is possible to reduce consumption of the mica tape; reduces manufacturing costs; and appearance of a cable being satisfactory at the time of forming an insulation layer.

Description

FIRE RESISTANT CABLE AND MANUFACTURING METHOD THEREOF

The present invention relates to a refractory cable and a method of manufacturing the refractory cable. More particularly, the present invention relates to a refractory cable having improved lamination structure and manufacturing method, And a method of manufacturing the same.

Generally, refractory cable is a cable used for fire protection in case of fire. It is able to supply electric current among the combustion of cable caused by fire, and supplies power to sprinkler, emergency generator, etc., and is useful for internal escape machine and fire suppression even in case of fire. The refractory cable is fabricated with a layer of refractory tape (refractory material) between the conductor and the insulator to withstand flames.

1 is a cross-sectional view showing a general refractory cable having a plurality of insulation core wires. The refractory cable 10 includes at least one insulation core 11 and a protective sheath layer 12 formed outside the insulation core 11 to protect the insulation core 11, (12) is filled with a filler (13) around the insulated core (11). The insulation core 11 is formed of at least one conductor portion 11a made of copper wire or the like, a refractory tape layer 11b spirally covering the conductor portion 11a, And an insulator layer 11c.

The refractory tape layer 11b prevents a short circuit between the conductor portions 11a and disconnection of the conductor portion 11a in the event of a fire. As the refractory tape layer 11b, glass tape or mica tape is used. Korean Registered Utility Model No. 20-0326511 and Korean Registered Patent No. 10-0546929 disclose related technologies. Grass tapes are advantageous in terms of cost reduction, but glass tapes are less used than mica tapes in terms of insulation performance and electrical insulation performance. On the other hand, mica tapes have excellent electrical insulation performance at high temperatures, and are excellent in heat insulation and flame shielding effect. Mica tape is a structure in which a mica (mica) is coated on a glass fiber base.

However, refractory cables with conventional mica tapes exhibit high fire resistance enough to pass the fire test or spray test required by international standards such as BS8491: 2008, IEC 60331-1: 2009, and IEC 60331-2: 2009 can not do. Accordingly, in order to pass the fire resistance test or the spray test required by the international standard, a method of winding a mica tape of 2 to 3 layers or more, winding a mica tape of 2 to 3 layers or more, and winding the glass tape further was proposed. However, in this case, there is a problem that the consuming amount of the mica tape is large and the manufacturing cost is increased due to the winding process of the additional glass tape, and the fire resistance performance is not so high as compared with the high cost.

On the other hand, there has been proposed a technique of filling a space between conductors of a conductor with a filler (silicon) in a refractory tape layer or forming a glass fiber braid on a mica tape to compensate for the mechanical disadvantages of a mica which tends to break at high temperatures. There is a problem in that a cost required for carrying out a silicon filling process or a braiding process is large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a mica tape which has a high mica tape consumption and manufacturing cost while maintaining a high fire- And a method for manufacturing the same.

In order to accomplish the above object, a refractory cable according to the present invention includes a conductor portion, a first mica tape which spirally surrounds a conductor portion and has a mica coated on an outer surface thereof, a first mica tape which surrounds the first mica tape, A second mica tape in contact with the mica of the mica tape, and an insulating layer formed outside the second mica tape.

The overlapping rate at which the first mica tape and the second mica tape are wound helically is 1/10 to 1/2 of the tape width. The first mica tape and the second mica tape are coated with mica on one side of the substrate, the substrate is glass fiber, and the mica includes phlogopite or Muscovite.

A method of manufacturing a refractory cable according to the present invention includes a first tape forming step of spirally wrapping a first mica tape on an outer surface of a conductor portion so that a conductor portion formed by a core wire is conveyed in a lengthwise direction, A second tape forming step of spirally wrapping a second mica tape on an outer surface of the first mica tape so that the mica coating surface is inward in the longitudinal direction in which the conductor part wrapped around the first mica tape is conveyed; And an insulating layer forming step of forming an insulating layer.

The overlapping rate at which the first mica tape or the second mica tape is helically wound in the first tape forming step and the second tape forming step is 1/10 to 1/2 of the tape width. In the second tape forming step, the second mica tape is wound so as to intersect with the first mica tape in a helical manner.

According to the refractory cable and the method of manufacturing the same according to the present invention, it is possible to reduce the consumption amount and manufacturing cost of the mica tape while maintaining the high fire resistance performance of passing through the fire resistance test or the spray test with only two layers of the mica tape.

According to the present invention, the mica of the first mica tape and the mica of the second mica tape are combined at high temperature and high pressure while the mica is prevented from being broken by the crest formed on the outer surface of the conductor at the time of the fire resistance test, Contrary to the breakage of the mica, the damage to the mica is less.

Further, according to the present invention, since the overlapping ratio of the mica tape can be reduced, the amount of the mica tape can be reduced, and the manufacturing cost is reduced, and the appearance of the cable is improved at the time of forming the insulating layer.

1 is a cross-sectional view showing a general refractory cable having a plurality of insulation core wires.
2 is a cross-sectional view showing a refractory cable according to an embodiment of the present invention.
3 is a detailed sectional view showing a part of FIG. 2 in detail.
Fig. 4 is a view showing a state in which the first mica tape and the second mica tape of Fig. 2 are wrapped around the conductor. Fig.
5 is a flowchart showing a method of manufacturing a refractory cable according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that, in the drawings, the same components are denoted by the same reference symbols as possible. Further, the detailed description of known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some of the components in the drawings are exaggerated, omitted, or schematically illustrated.

Fig. 2 is a cross-sectional view showing a refractory cable according to an embodiment of the present invention, Fig. 3 is a detailed sectional view showing a part of Fig. 2 in detail, Fig. 4 is a sectional view showing the first and second mica tapes of Fig. And Fig. The refractory cable 100 according to the embodiment of the present invention includes a conductor portion 110, a first mica tape 120, a second mica tape 130, and an insulating layer 140 .

The conductor portion 110 is composed of one or more conductors. The conductor is an electrically conductive metal and is made of copper, tin (Sn), silver (Ag), gold (Au), aluminum (Al), nickel (Ni), zinc (Zn), tungsten (Fe) and the like, or an alloy of two or more metals. The conductor may be formed by plating a metal having excellent electrical conductivity with another metal having excellent corrosion resistance and abrasion resistance. For example, the conductor may be composed of a copper wire plated with tin (Sn).

The first mica tape 120 includes a mica layer 122 spirally wrapping the conductor 110 and coated on the outer surface of the base 121 and a second mica tape 130 A mica layer 132 is formed on the inner surface of the substrate 131 to cover the mica tape 120 and the mica layer 132 is in contact with the mica layer 122 of the first mica tape 120. Since the mica layer 122 of the first mica tape 120 is in contact with the mica layer 132 of the second mica tape 130 in the present invention, The mica of the second mica tape 130 and the mica of the second mica tape 130 are gathered at a high temperature and a high pressure. On the other hand, in the conventional refractory cable, since the mica-coated surface is in contact with the conductor portion, the mica is crushed into the corrugation formed on the outer surface of the conductor portion during the fire resistance test.

The first mica tape 120 and the second mica tape 130 may be those conventionally used in the art. The first mica tape 120 and the second mica tape 130 may be prepared by crushing the mica raw mica, An aggregate mica tape manufactured by coating a substrate 121 (131) with a silicone adhesive or the like and drying it is used. The first mica tape 120 and the second mica tape 130 are formed to have a weight ratio of 60 to 70% by weight of mica, 15 to 25% by weight of a base material and 10 to 16% by weight of an adhesive such as epoxy or silicone %. At this time, it is preferable that the mica tape is fired at 750 DEG C or higher to improve the fire resistance performance or the insulation performance of the mica, and the foreign substances contained in the raw light or the organic substances such as the adhesive are burned and removed.

The substrate 121 (131) may be selected from a fiber substrate, a polymer film, and the like. Preferably, glass fiber is used as the fiber substrate. The glass fiber may be S- (E-Glass), and the like. However, it is also possible to use tapes such as glass cloth tape and woven glass fabric having a lower grade than the tape type. As a material of the polymer film, a polymer film such as polyethylene, polyamide, and aromatic polyamide film can be used.

The mica constituting the mica layers 122 and 132 is composed of phlogopite (KMg ₃ AlSi ₃ O ₁₀ (OH, H) ₂ ) and muscovite (KAl ₂ (AlSi) ₄ O ₁₀ (OH, H) _2, etc. It is preferable that the mica uses a soft mica mainly composed of phlogopite. The soft mica is preferably used in terms of performance as an electric insulator, Although it is inferior to a hard mica having a main ingredient of Muscovite, it has a high heat resistance property and has a merit to maintain its molecular structure even at 900 DEG C, so that it can be usefully used as a material for high fire resistance required in the present invention.

4, the first mica tape 120 and the second mica tape 130 are wound to overlap each other by a predetermined amount when wound helically. The overlap amount P is 1/10 of the tape width W To 1/2, but it is preferably set to 1/5 to 1/4 (20% to 25%) of the tape width (W). In order to increase the fire resistance, the overlapping ratio of the conventional fireproof cable is 1/3 to 1/2 of the tape width. However, according to the present invention, since the overlapping ratio can be reduced and the fire resistance performance can be improved, the amount of mica tape can be reduced, And the appearance of the cable becomes good when the insulating layer is formed. On the other hand, the first mica tape 120 and the second mica tape 130 are wound so as to cross each other in a spiral manner.

The insulating layer 140 is formed by extrusion so that an insulating material such as a synthetic resin or rubber surrounds the outside of the second mica tape 130. The outer side of the insulating layer 140 may be covered with a coating material through extrusion.

5 is a flowchart showing a method of manufacturing a refractory cable according to an embodiment of the present invention. In this embodiment, a manufacturing method will be described taking a structure in which a covering layer is formed outside the insulating layer 140 of the refractory cable 100 shown in FIG. 2 as an example. The apparatus used in the manufacturing method of the present invention may use an apparatus similar to the apparatus disclosed in Korean Patent No. 10-0546929.

As shown in the drawing, a method of manufacturing a refractory cable includes a core wire forming step S110, a first tape forming step S120, a second tape forming step S130, an insulating layer forming step S140, (S150), and a cable winding step (S160).

The core forming step S110 is a step of forming a conductor 110 having a predetermined diameter and having a predetermined size and forming a conductor 110 having a single core by stranding a plurality of drawn conductors.

In the first tape forming step S120, the first mica tape 120 is wound around the conductor portion 110 so that the mica coating surface (mica layer) 122 is outside in the longitudinal direction in which the conductor portion 110, And the second tape forming step is a step of wrapping the second mica tape 130 (130) so that the mica coated surface (mica layer) 132 is inward in the longitudinal direction in which the conductor portion wrapped with the first mica tape 120 is fed Is spirally wrapped around the outer surface of the first mica tape 120.

As shown in FIG. 4, in the first tape forming step (S120) and the second tape forming step (S130), the overlap amount P (P) in which the first mica tape 120 or the second mica tape 130 is helically wound May be 1/10 to 1/2 of the tape width W, but is preferably 1/5 to 1/4 (20% to 25%) of the tape width W. [ In the second tape forming step S130, the second mica tape 130 is wound so as to intersect with the first mica tape 120 in a helical manner.

The insulating layer forming step S140 is a step of forming the insulating layer 140 in a state that the second mica tape 130 is wrapped around and the insulating layer 140 is formed on the outer side of the second mica tape 130 by the insulating resin material melted and supplied. The insulating layer 140 is extruded by a diameter.

In the coating layer forming step S150, the outer covering material is extruded outside the single refractory cable 100 formed with the insulating layer 140, or a plurality of refractory cables 100 having the insulating layer 140 are bundled and bundled And extruding the outer covering material. The space between the refractory cables 100 may be filled with a filler to extrude the outer covering material.

The cable winding step (S160) is a step of winding the coated finished cable to the bobbin.

Table 1 shows an example in which the refractory cable manufactured according to the embodiment of the present invention is compared with a conventional refractory cable.

The test example of the present invention is such that the substrate of the first mica tape 120 is in contact with the conductor portion 110 and the mica layer of the first mica tape 120 and the mica layer of the second mica tape 130 are in contact with each other Is an example of a refractory impact test for a refractory cable. A comparative test was conducted in the same manner as in Example 1 except that the mica layer of the first mica tape 120 was in contact with the conductor portion 110 and the base of the first mica tape 120 was in contact with the mica layer of the second mica tape 130, The test results are shown in Fig.

The fire resistance impact test was carried out in accordance with the international standards of IEC 60331-1 and IEC 60331-2, followed by flame application for 120 minutes and impact for 5 minutes at intervals of 5 minutes.

Test Example
(Implementation and comparison) Cable length and voltage Bending radius of cable Mica tape width
(Overlap Rate) Test result Remarks Example 1 2000 mm,
250V 168mm 1 layer 6mm (not measurable),
2nd floor 6mm (32.3%) No breakage or disconnection of conductors pass Example 2 2000 mm,
1000V 126mm 1 layer 7mm (measurement impossible),
2nd floor 7mm (41.7%) No breakage or disconnection of conductors pass Comparative Example 1 1200 mm,
1000V 84.48mm 1 layer 7mm (0%),
2nd floor 9mm (0%) After 10 minutes of test, conductor breakage and disconnection / crosstalk fail Comparative Example 2 1200 mm,
1000V 66.72 mm The first floor is 7mm (12.4%),
Second floor 8mm (13.3%) 19 minutes after the test, breakage of conductor and breakage / crosstalk fail Comparative Example 3 1200 mm,
1000V 66.72 mm The first floor is 7mm (30.7%),
The second floor 8mm (32.1%) After 10 minutes of test, conductor breakage and disconnection / crosstalk fail Comparative Example 4 1200 mm,
1000V 85.68mm The first floor is 10mm (31%),
Second floor 10mm (32.6%) After 8 minutes of test, conductor breakage and disconnection / crosstalk fail

As shown in Table 1, in the test examples of the present invention, the conductors were not damaged at all during the test period, and they failed the crossing between adjacent conductors or conductors. Thus, in the comparative example, Min and breakage of the conductor portion and disconnection or crosstalk between conductors occurs. The bending radius of the cable is the radius at which it bends during testing according to the diameter and number of conductors of the insulation core.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of the present invention in order to facilitate the understanding of the present invention and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: Refractory cable 110: Conductor part
120: first mica tape 121, 131: substrate
122, 132: mica layer 130: second mica tape
140: insulating layer

Claims (6)

A conductor portion,
A first mica tape spirally covering the conductor portion and coated with a mica on an outer surface thereof,
A second mica tape surrounding the first mica tape and coated on the inner surface of the first mica tape and contacting the mica of the first mica tape;
And an insulating layer formed on an outer side of the second mica tape. The method according to claim 1,
Wherein the overlapping amount of the first mica tape and the second mica tape wound in a spiral form is 1/10 to 1/2 of the tape width. The method according to claim 1,
And the second mica tape is wound so as to intersect with the first mica tape in a spiral manner mutually. The method according to any one of claims 1 to 3,
The first mica tape and the second mica tape are coated with a mica on one side of the substrate and the substrate is glass fiber and the mica includes phlogopite or muscovite Fireproof cable. A first tape forming step of spirally surrounding the first mica tape on the outer surface of the conductor portion so that the mica coated surface is outside in the longitudinal direction in which the conductor portion formed by the core wire is fed,
A second tape forming step of spirally wrapping a second mica tape on the outer surface of the first mica tape so that the mica coating surface is inward in the longitudinal direction in which the conductor part wrapped with the first mica tape is conveyed;
And forming an insulating layer in a state in which the second mica tape is wrapped around the insulating layer. The method of claim 5,
Wherein the overlapping amount of the first mica tape or the second mica tape wound in a spiral shape in the first tape forming step and the second tape forming step is 1/10 to 1/2 of the tape width. A method of manufacturing a cable.

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