JPS61148707A - Flame resisting cable - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Polyethylene or polyvinyl chloride, which are thermoplastic resins, are commonly used as exterior coating materials for current-carrying conductors or optical fibers for electric power or communications.

Therefore, by adding a flame retardant, the combustion of these resins can be suppressed to some extent, but smoke and toxic gases are more likely to be generated. For this reason, calcium carbonate and the like are mixed in, but only to the extent that they can slightly suppress the combustion rate.

It is easier to suppress the chain reaction of combustion with this boiling thermosetting resin by mixing a flame retardant and a nonflammable light suppressant, or by carbonizing it.

Therefore, the present invention forms a flame-retardant thermosetting resin layer on the exterior by interposing a fiber layer with poor thermal conductivity on the conventional thermoplastic resin coating, as shown in FIG. As shown in FIG. This is a flame-retardant cable in which the surface layer is impregnated with a flame-retardant thermosetting resin and cured directly to form a flame-retardant coating layer 5.

However, by leaving the fibrous layer 3 as it is without impregnating it with the thermosetting resin in the vicinity of the fibrous layer 3 that is in close contact with the inner coating layer 2, a heat-insulating effect can be achieved.

In addition, if the amount of added flame retardant, non-combustible light suppressant, etc. is increased in order to increase the degree of flame retardancy of the flame retardant coating layer 5, the rigidity of this layer will inevitably increase and the flexibility required for the cable will be increased. descend.

Therefore, as shown in the drawings from FIG. By impregnating the cable with a curable resin and directly hardening it to form a flame retardant coating layer 5 with a corrugated longitudinal section, the apparent rigidity due to the shape can be reduced, thereby preventing loss of flexibility of the cable. Goru.

In addition, by leaving the vicinity of the fiber layer 3 that is in close contact with the inner coating layer 2 as a fiber layer, it has a heat insulation effect, and
Since flexibility is imparted to the bond between the flame-retardant coating layer 5 and the inner coating layer 2, increase in rigidity of the cable due to the flame-retardant coating layer 5 can be prevented.

In order to form the grooves 4 in the fiber layer 3, the inner coating layer 2 of thermoplastic resin is heated at a plasticizing temperature as shown in FIG.
While supplying the fiber layer 3, the fiber layer 3 is pressed with a first stage uneven roll 6 or the like to bring the fiber layer 3 into close contact with the inner coating N2, and at the same time, grooves 4 are formed therein, and a flame-retardant thermosetting resin is applied to this surface layer. After being impregnated, the wave-shaped flame-retardant coating layer 5 can be formed by heating and molding using a second stage uneven roll 8 or the like. In this case groove 4
In order to increase the depth of the inner coating layer 2, it is desirable to provide grooves in advance over the entire length of the inner coating layer 2. This method can be performed by using a pre-loaded uneven roll having substantially the same shape as the O-crotch uneven roll 6, or the like.

It is also possible to form this groove using an extrusion die with a rotating base.

In addition, the material for the fiber layer 3 is a synthetic resin nonwoven fabric.

Nonwoven fabrics such as natural fiber nonwoven fabrics and glass fiber mats, and woven fabrics made of the same materials as above can be used. These fibers are compressed by the first stage uneven roll 6, and the inner coating layer 2 under the plasticizing temperature
It can be fused by sinking into the surface.

Also, due to the nature of the material, adhesive is applied to the surface of the fiber layer 3 in advance.
It is also possible to make the adhesive layer of blood or thermoplastic resin adhesion resistant so that the adhesive layer can be adhered at the plasticizing temperature.

After the fiber layer 3 is brought into close contact with the inner coating layer 2 to form the grooves 4, the surface layer is impregnated with a flame-retardant thermosetting resin by dropping or by forced extrusion using an extruder. Thereafter, it is pressed with a heated second stage uneven roll 8 to form a corrugated flame retardant coating layer 5. The AP6 diagram and the off diagram show the case where four belt-shaped fiber layers 3 are supplied in the longitudinal direction of the cable. At this time, the ends of each belt overlap and are pulled in, but this overlapping part is covered with thermosetting resin,
Since it is cured and integrated, there is an advantage that a seamless flame retardant coating layer 5 can be obtained.

Another method for forming grooves 4 in the fiber layer 3 is the eighth method.
As shown in the figure, the inner coating layer 2 made of thermoplastic resin is kept in a plasticized state, and the fiber layer 3, in which a large number of string-like core materials 9 are superimposed on the inner surface in a striped manner, is wound around the inner coating layer 2. At the same time, grooves 4 are formed in the two by pressing with a first-stage uneven roll 6 or the like, and after impregnating the surface layer with a flame-retardant thermosetting resin, a second-stage uneven roll 8 or the like is used to form a groove 4. The corrugated flame-retardant coating layer 5 can be formed by heat molding.

However, in the present invention, since the flame-retardant coating layer 5 is formed seamlessly, even if the internal coating layer 2 becomes heated and melts, it will not flow out to the outside and will not catch fire. It has the characteristic that combustion is unlikely to occur.

[Brief explanation of the drawing]

The figures show an example of the implementation of the present invention, in which Fig. 1 is a surface survey view with a partial longitudinal section of a flame-retardant cable when the outer peripheral surface is flat, and Fig. FIG. 9 is a partial vertical cross-sectional view of the case where grooves 4 are provided. FIG. Fig. 4 is a partial longitudinal cross-sectional view of the case in which grooves 4 are provided on the fiber layer 3 by using a string-like core material 9. Fig. 9 is a partial longitudinal cross-sectional view of the case in which the flame-retardant coating layer 5 is formed thereon. Surface diagram. Figure 6 is a longitudinal cross-sectional view of the explanatory drawing showing the manufacturing method of the flame-retardant cable in Figure 3, the off view is a cross-sectional view taken along line X-X in Figure 6, and Figure 8 is a cross-sectional view of the flame-retardant cable in Figure 5. FIG. 3 is a longitudinal cross-sectional view of an explanatory diagram showing a manufacturing method. 1... Current-carrying conductor or optical fiber 0 bundle 2 Internal coating layer 3 Wc fiber layer 4- Groove 5 Flame-retardant coating layer 6 - First stage uneven roll 7 Thermosetting resin supply device 8 Second stage uneven roll 9- Set core material patent applicant: Tai 1) Ryozo, k, +, -. Sea - slag 2 fig. grass 3 fig. grass -! l-fattening daen

Claims (4)

[Claims] (1) An inner coating layer 2 of thermoplastic resin is applied on the periphery of a bundle 1 of current-carrying conductors or optical fibers for power or communication, and a fiber layer 3 made of non-woven fabric or woven fabric is adhered to the outer periphery of the inner coating layer 2. A flame-retardant cable whose surface layer is impregnated with a flame-retardant thermosetting resin and cured directly to form a flame-retardant coating layer 5. (2) A groove 4 in the circumferential direction or coiling direction is formed over the entire length of the fiber layer 3 made of non-woven fabric or woven fabric, a flame-retardant thermosetting resin is impregnated from the surface layer of this fiber layer 3, and it is cured as it is. The flame-retardant cable according to claim 1, wherein the flame-retardant coating layer 5 has a corrugated longitudinal section. (3) At the same time, the inner coating layer 2 of thermoplastic resin is pressed with the first stage uneven roll 6 etc. while supplying the fiber layer 3 under the plasticizing temperature, so that the fiber layer 3 is brought into close contact with the inner coating layer 2. After forming grooves 4 in this and impregnating the surface layer with a flame-retardant thermosetting resin, the wave-shaped flame-retardant coating layer 5 is formed by heating and molding with a second stage uneven roll 8 or the like. A flame-retardant cable according to claim 2. (4) The inner coating layer 2 made of thermoplastic resin is kept in a plasticized state, and the fiber layer 3 in which a large number of string-like core materials 9 are superimposed on the inner surface in a striped manner is wound around the inner coating layer 2, and the first stage Uneven roll 6
At the same time, a groove 4 is formed in this to make them stick together by pressing with a second stage uneven roll 8 etc. After impregnating the surface layer with a flame-retardant thermosetting resin, it is heated and formed with a second stage uneven roll 8 etc. to form a corrugated shape. A flame-retardant cable according to claim 2, wherein a flame-retardant coating layer 5 is formed.