KR102580923B1 - Bundle of cable and method for packaging the same - Google Patents

Abstract

The present invention relates to bundles of electrical wires and methods for packaging them. Specifically, the present invention facilitates packaging of wires with a lowered surface friction coefficient to improve laying properties when transporting them in the form of a bundle. In particular, the shape of the bundle can be stably maintained even when shaken or impacted, improving transportability and workability. It relates to an improved bundle of wires and a method of packaging the same.

Description

Bundle of cable and method for packaging the same}

The present invention relates to bundles of electrical wires and methods for packaging them. Specifically, the present invention facilitates packaging of wires with a lowered surface friction coefficient to improve laying properties when transporting them in the form of a bundle. In particular, the shape of the bundle can be stably maintained even when shaken or impacted, improving transportability and workability. It relates to an improved bundle of wires and a method of packaging the same.

Electric wires used for general electrical work or electrical equipment wiring, indoor wiring, etc. have excellent heat resistance, flame retardancy, water resistance, chemical resistance, insulation, cold resistance, oil resistance, etc. against fire, flooding, etc. This is required.

In addition, the wires for indoor wiring, such as for lighting and electric heating, are installed in a way that when laid uncovered, they are introduced into the interior of the ceiling at a specific point such as the ceiling, wall, or floor, and then pulled out at a certain distance from the specific point. , Here, the wires introduced into the interior of the ceiling, wall, floor, etc. are transported through a wire pipe made of a material such as PVC, for example, which protects the wire and guides it until it is pulled out.

The wire transported through the conduit may be difficult to transport if it exhibits excessive flexibility or stiffness, and may be difficult to transport due to friction with the inner wall of the conduit or other wires introduced together. In particular, when the electric wire is transported through the conduit in a curved area according to the structure of the ceiling, wall, or floor of a building or facility, transport may be even more difficult.

Therefore, the electric wire has flexibility and rigidity appropriate for transport, and at the same time, the surface of the insulating layer constituting the electric wire is designed to improve the laying efficiency of the electric wire by minimizing friction between the electric wire and the inner wall of the conduit or other electric wires transported together. The coefficient of friction needs to be sufficiently low.

However, when transporting wires with a lower surface friction coefficient to improve laying properties, a bundle of wires is formed by wrapping the wires around a support such as a cylinder and then separating them from the support, and multiple bundles of these wires are placed on a pallet. It is transported by stacking it in multiple layers on the back, but due to the low surface friction coefficient of the wires, the bundle does not maintain its original shape due to shaking or shock during transportation, and as a result, the bundle of wires stacked in multiple layers is tilted or collapsed. There is a problem with extremely low performance.

Therefore, packaging is easy when transporting wires with a lowered surface friction coefficient to improve laying properties in bundle form, and in particular, the shape of the bundle can be stably maintained even when shaken or impacted, making bundles of wires with improved transportability and workability. and its packaging method are urgently needed.

The purpose of the present invention is to provide a bundle of wires with a lower coefficient of surface friction to improve laying properties, and a method for packaging the wires that can be easily packaged and transport efficiency can be improved when transporting the wires in a bundle form.

The present invention provides a bundle of wires with improved transportability and workability, and a method for packaging them, as the wires with a lower coefficient of surface friction to improve laying are able to stably maintain the shape of the bundle even when shaken or impacted when transported in bundle form. The purpose is to

In order to solve the above problems, the present invention,

A bundle of wires containing a conductor and an insulating layer containing an external lubricant to lower the surface friction coefficient while surrounding the conductor. The relationship between height (h) and thickness (w) of the bundle of wires is defined in Equation 1 below: Provides a bundle of wires, characterized in that.

[Equation 1]

h≤1.5w

On the other hand, it is a bundle of wires including a conductor and an insulating layer surrounding the conductor, wherein the insulating layer is made of multiple layers, and the outermost layer of the insulating layer includes an external lubricant to lower the surface friction coefficient, and the wire The bundle of provides a bundle of wires, characterized in that the relationship between height (h) and thickness (w) is defined in Equation 1 below.

[Equation 1]

h≤1.5w

In addition, a bundle of wires including a conductor and an insulating layer containing an external lubricant for lowering the surface friction coefficient while surrounding the conductor, the nominal cross-sectional area (d) of the conductor of the wire, the height (h) and the outer diameter of the bundle of wires. (D) provides a bundle of wires, characterized in that it satisfies the conditions according to Equations 2 and 3 below.

[Equation 2]

h=ad

In Equation 2 above,

a is 20 to 50.

[Equation 3]

D=bh+c

In Equation 3 above,

b is 0.4 to 0.6, and c is 250 to 300.

And, a bundle of wires including a conductor and an insulating layer surrounding the conductor, wherein the insulating layer is made of multiple layers, and the outermost layer of the insulating layer includes an external lubricant for lowering the coefficient of surface friction, and the wire The nominal cross-sectional area of the conductor (d), the height (h), and the outer diameter (D) of the bundle of wires satisfy the conditions according to Equations 2 and 3 below.

[Equation 2]

h=ad

In Equation 2 above,

a is 20 to 50.

[Equation 3]

D=bh+c

In Equation 3 above,

b is 0.4 to 0.6, and c is 250 to 300.

Here, a bundle of wires is provided, characterized in that the elastic modulus of the conductor is 15,000 to 21,000 MPa.

Additionally, a bundle of wires is provided, characterized in that the conductor is a single wire.

In addition, a bundle of wires is provided, wherein the surface friction coefficient of the insulating layer or the outermost layer of the insulating layer made of multiple layers is 0.16 to 0.40.

Furthermore, it provides a bundle of wires, characterized in that the bundle of wires is bound by binding means at 4 to 6 points to maintain its shape.

On the other hand, the bundle of wires has a height (h) of 60 to 70 mm, a thickness (w) of 50 to 60 mm when the nominal cross-sectional area (d) of the conductor of the wire is 1.5 mm2, and the conductor of the wire has a thickness (w) of 50 to 60 mm. Provided is a bundle of wires, characterized in that the height (h) is 75 to 85 mm and the thickness (w) is 55 to 65 mm for a nominal cross-sectional area (d) of 2.5 mm2.

In addition, the bundle of wires has a height (h) of 60 to 70 mm, an outer diameter (D) of 290 to 330 mm when the nominal cross-sectional area (d) of the conductor of the wire is 1.5 mm2, and the conductor of the wire has a Provided is a bundle of wires, characterized in that the height (h) is 75 to 85 mm for a nominal cross-sectional area (d) of 2.5 mm2 and the outer diameter (D) is 300 to 340 mm.

And, in Equations 3 and 4, a is 25 to 45, b is 0.5 to 0.6, and c is 265 to 270.

Meanwhile, stacking the bundle of wires in multiple stages on the top of the pallet; and wrapping the multi-stage bundle of wires with a packaging member at least once.

Here, a method of packaging a bundle of wires is provided, which further includes the step of inserting a friction increasing member between the ends when stacking the bundle of wires in multiple stages.

In addition, a method of packaging a wire bundle is provided, wherein the friction increasing member is paper.

In addition, a method of packaging a wire bundle is provided, wherein the packaging member is a heat shrink film.

Furthermore, it provides a packaging method for a bundle of wires, characterized in that the pallet and the bundle of wires stacked in multiple stages are entirely wrapped.

In addition, a method of packaging a wire bundle is provided, characterized in that wrapping 1 to 6 times with the packaging member.

In addition, a method of packaging a wire bundle is provided, wherein the heat shrinkable film has a thickness of 0.01 to 0.2 mm.

Although the bundle of wires according to the present invention is a bundle of wires with a lowered surface friction coefficient to improve laying, it is easy to package through precise control of the bundle shape and stably maintains the shape of the bundle even when shaken or shocked during transportation. It shows excellent effects with greatly improved transportability and workability.

Figure 1 schematically shows a bundle of wires and packaging of 100 bundles according to the present invention.
Figure 2 is a cross-sectional view schematically showing the cross-sectional structure of an embodiment of an electric wire forming a bundle of electric wires according to the present invention.
Figure 3 is a cross-sectional view schematically showing the cross-sectional structure of another embodiment of an electric wire forming a bundle of electric wires according to the present invention.
Figure 4 is a cross-sectional view schematically showing the cross-sectional structure of another embodiment of an electric wire forming a bundle of electric wires according to the present invention.
Figure 5 schematically shows a virtual laying work environment for measuring the static friction coefficient and dynamic friction coefficient of the wires forming the bundle of wires according to the present invention.
Figure 6 shows the transport route through which 100 bundles of wires according to the present invention were packaged and transportability evaluated as shown in Figure 1b.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached 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 disclosure will be thorough and complete, and so that the spirit of the invention can be sufficiently conveyed to those skilled in the art. Like reference numerals refer to like elements throughout the specification.

Figure 1a schematically shows a bundle of wires according to the present invention, and Figure 1b schematically shows the packaging of 100 bundles of wires shown in Figure 1a.

As shown in FIG. 1, the bundle 100 of wires according to the present invention can be formed by winding the wire 110 around a support such as a cylinder of a certain outer diameter and then separating it from the cylinder, thereby forming an overall shape of the cylinder. It can have a shape. Additionally, the bundle of wires 100 according to the present invention may be bound at 4 to 6 points using a binding means such as tape 120.

When lowering the surface friction coefficient of the wire 110 to improve the laying properties of the wire 110 forming the bundle 100 of the wire according to the present invention, packaging the wire 110 for transporting the wire 110 The process, that is, the task of stacking the wire bundle 100 to a certain height, is extremely difficult, which not only reduces transportation efficiency, but also causes the shape of the wire bundle 100 to be deformed due to shaking or impact during transportation, resulting in completion of transportation. Therefore, when dismantling the packaging, there is a problem that the workability is extremely reduced, such as the column of the wire bundle 100 tilting or collapsing.

Therefore, in order to solve the above problem, the bundle of wires 100 can be controlled so that the relationship between its height (h) and thickness (w) is defined in Equation 1 below.

[Equation 1]

h≤1.5w

In addition, the bundle of wires 100 according to the present invention has the size of the wire bundle 100, that is, the height of the wire bundle 100, according to the standard of the wire 110, that is, the nominal cross-sectional area (d) of the conductor ( h) and outer diameter (D) can satisfy the conditions according to Equations 2 and 3 below.

[Equation 2]

h=ad

In Equation 2 above,

a is 20 to 50, preferably 25 to 45.

[Equation 3]

D=bh+c

In Equation 3 above,

b is 0.4 to 0.6, preferably 0.5 to 0.6,

c is 250 to 300, preferably 265 to 270.

Here, in Equation 1, when the height (h) of the bundle of wires exceeds 1.5 times the thickness (w) or when the conditions of Equations 2 and 3 are not satisfied, as shown in FIG. 1B, The process of packaging more than 100 bundles of wires (100) is extremely difficult, which reduces transportation efficiency, and when transporting the bundles of wires (100) packaged in more than 100 pieces, the bundles (100) of wires are damaged by shaking or impact. ) may not maintain its original shape and be deformed, resulting in a significant decrease in workability, such as tilting or collapsing of the bundled columns of multi-layered wires when dismantling the packaging after completion of transportation.

For example, for a bundle 100 of wires with a nominal cross-sectional area (d) of the conductor of 1.5 mm2 according to standard KS C 3341, the height (h) is 60 to 70 mm, the thickness (w) is 50 to 60 mm, and the outer diameter is (D) may be 290 to 330 mm, and for a bundle 100 of wires with a nominal cross-sectional area (d) of the conductor according to standard KS C 3341 of 2.5 mm2, the height (h) may be 75 to 85 mm and the thickness (w ) may be 55 to 65 mm, the outer diameter (D) may be 300 to 340 mm, the height (h) may be 100 to 110 mm, the thickness (w) for a bundle of wires with a nominal cross-sectional area (d) of the conductor of 4 mm2. may be 60 to 66 mm, and the outer diameter (D) may be 300 to 340 mm.

Meanwhile, the packaging method of the wire bundle 100 according to the present invention includes the steps of stacking the wire bundle 100 in multiple stages on top of a pallet 200, and stacking the wire bundle 100 and the pallet 200 stacked in multiple stages. It may include the step of wrapping together with a packaging member one or more times. Here, the packaging member may be, for example, a heat-shrink film, and the thickness of the heat-shrink film may be about 0.05 mm or more, preferably 0.08 mm or more.

In addition, when stacking the wire bundle 100 in multiple stages on the top of the pallet 200, each of the stacked wire bundles is packaged with a separate packaging material, or a friction material such as paper is inserted between the stacked stages to form the wire bundle. By further increasing the friction between the wire bundles, the packaging process can be further facilitated or the wire bundle pillar can be further prevented from tilting or collapsing when the packaging is dismantled after transportation.

Figure 2 is a cross-sectional view schematically showing the cross-sectional structure of an embodiment of an electric wire forming a bundle of electric wires according to the present invention.

The wire shown in FIG. 2 may be a non-halogen-based flame retardant polyolefin cross-linked insulated wire for indoor wiring, and may be composed of a conductor 10 and an insulating layer 20 surrounding it. In addition, as shown in Figure 2b, the wire may additionally include a separate insulating layer 30 on the outside of the insulating layer 20, and therefore, the inner insulating layer 20 is an insulating inner layer and an outer insulating layer. Layer 30 may be an insulating outer layer.

The conductor 10 may be made of a conductive metal such as copper or aluminum, and is preferably made of copper. The conductor 10 may be a single wire as shown in FIGS. 2A and 2B, or may be a stranded wire obtained by twisting a plurality of solid wires, for example, 7 or 19, as shown in FIG. 2C.

The diameter of the conductor 10 is determined according to the rated voltage of the wire. For example, the conductor 10 used in a non-halogen-based flame retardant polyolefin cross-linked insulated wire for indoor wiring with a rated voltage of 450/750 V is a single wire. The nominal cross-sectional area is about 1.5 to 10 ㎟, and in the case of a stranded wire with a number of strands of 7, the diameter of each strand may be about 0.53 to 1.35 mm, and the nominal cross-sectional area may be 1.5 to 300 SQ, especially 1.5 to 4 SQ.

Non-halogen-based flame-retardant polyolefin cross-linked insulated wire for indoor wiring is used for indoor wiring such as for lighting and electric heating. When installed in a non-exposed manner, it is introduced into the interior of the ceiling, etc. from a specific point such as the ceiling, wall, or floor, and then connects to the specific point and a certain amount of time. It is installed in a way that it is pulled outward from spaced points. Here, the wires that are drawn into the interior of the ceiling, wall, floor, etc. are installed through a conduit made of a material such as PVC, for example, that protects it and guides it until it is pulled out. is transported through

The wire transported through the conduit may be difficult to transport if its flexibility is too excessive or its stiffness is too excessive, and may also be caused by friction with the inner wall of the conduit or other wires inserted together. Transport may be difficult. In particular, when the electric wire is transported through the conduit in a curved area according to the structure of the ceiling, wall, or floor of a building or facility, transport may be even more difficult.

Therefore, when the wire is used for indoor wiring, a precisely controlled balance of flexibility and stiffness is required to ensure excellent installation properties, and the flexibility and stiffness of the wire are determined by the elastic force of the wire. It is decided.

Here, the elastic force of the wire is determined by the elastic modulus of the conductor 10 and the insulating layer 20 that make up the electric wire. The elastic modulus of the insulating layer 20 is very small compared to the elastic modulus of the conductor 10. Therefore, it can be seen that the elastic force of the wire is predominantly determined by the elastic modulus of the conductor 10.

Therefore, when the wire is used for indoor wiring, the elastic modulus of the conductor 10 to ensure excellent installation properties may be about 15,000 to 21,000 MPa, preferably 17,000 to 18,000 MPa.

The insulating layer 20 may be formed by extrusion of an insulating composition. The insulating composition may include an electrically insulating polymer resin as a base resin, an antioxidant that inhibits oxidation of the polymer resin, an internal lubricant that improves compatibility between the polymer resin and additives, and a flame retardant to provide flame retardancy to the cable. .

Since the polymer resin is mostly an electrically insulating material, the electrically insulating polymer resin is not particularly limited as long as it satisfies the basic physical properties required for the insulating layer of electric wires used for indoor wiring, etc. The electrically insulating polymer resin may be, for example, a polyolefin resin such as polyethylene or polypropylene, and may preferably be polyethylene.

The polyethylene may be ultra-low-density polyethylene (ULDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), or a combination thereof, and is non-halogen-based flame retardant for indoor wiring. In terms of forming the insulating layer of the polyolefin cross-linked insulated wire, low-density polyethylene (LDPE) may be preferable. Additionally, the polyethylene may be a homopolymer, a random or block copolymer of ethylene and an α-olefin such as propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene, or a combination thereof.

Here, the low-density polyethylene (LDPE) has a lower degree of crystallinity than other polyethylene, so it has excellent loading properties for additives such as flame retardants, and unlike other polyethylene, it is manufactured without using a catalyst, so it has fewer foreign substances and has better electrical properties. Even better.

In addition to polyethylene as the base resin, the insulating composition includes polyolefin elastomers (POE) such as propylene-ethylene rubber (EPR) and propylene-ethylene diene rubber (EPDM), styrene-ethylenebutene-styrene copolymer, and styrene-ethylenepropylene-styrene copolymer. , Styrene-butadiene rubber (SBR) such as styrene-ethylene-ethylene propylene-styrene copolymer, styrene-butylene-styrene copolymer, ethylene vinyl acetate (EVA) (vinyl acetate content of about 15 to 40% by weight), etc. are added. It can be included as .

The polyolefin elastomer, styrene butadiene rubber (SBR), ethylene vinyl acetate (EVA), etc. (hereinafter referred to as 'polyolefin elastomer, etc.') have inferior mechanical properties and low melting point compared to the polyolefin, which reduces the heat resistance of the insulating composition. The low degree of crystallinity improves the loading properties for additives such as flame retardants. As a result, the polyolefin elastomer, etc. can further improve the flexibility, bendability, impact resistance, cold resistance, etc. of the insulating layer 20 formed by the insulating composition.

The total amount of heat absorption required when melting the base resin is about 30 to It may be 80 J/g. Here, when the total heat absorption required when melting the base resin is less than about 30 J/g, the heat resistance of the insulating composition may be poor, while about 80 If it exceeds J/g, the flexibility and elongation of the insulating composition may be insufficient.

The mixing ratio of the polyolefin resin and the polyolefin elastomer included as the base resin of the insulating composition can be appropriately selected within a range that satisfies the physical properties such as laying properties described later of the insulating composition and is not particularly limited, for example. , Based on 100 parts by weight of the base resin, the content of the polyolefin resin may be 25 to 70 parts by weight.

If the content of the polyolefin resin is less than 25 parts by weight, the mechanical properties and heat resistance of the insulating layer may be reduced, while if it is more than 70 parts by weight, the compatibility between the insulating composition and the flame retardant may be greatly reduced.

The insulating composition forming the insulating layers 20 and 30 is, for example, a metal hydroxide flame retardant such as magnesium hydroxide (Mg(OH) ₂ ) or aluminum hydroxide (Al(OH) ₃ ), or a melamine resin or melamine cyanurate. It may contain non-halogen-based flame retardants such as nitrogen-based flame retardants, and preferably includes magnesium hydroxide (Mg(OH) ₂ ).

Magnesium hydroxide (Mg(OH) ₂ ) among metal hydroxide flame retardants as the flame retardant has excellent heat resistance compared to other metal hydroxide flame retardants, suppresses the generation of bubbles even when heat is generated during high-speed extrusion of the insulating layers (20, 30), and maintains insulation resistance. This decline can be suppressed. In addition, magnesium hydroxide (Mg(OH) ₂ ) as a flame retardant can stably form char when the insulating layers 20 and 30 are burned during a fire, thereby maintaining the insulating function in place of the burned insulating layer. .

In general, as the flame retardant, inorganic particles such as magnesium hydroxide are hydrophilic with high surface energy, while base resins such as polyolefin are hydrophobic with low surface energy, so the inorganic particles have poor dispersibility in the base resin. Otherwise, it may have a negative effect on electrical characteristics. Therefore, in order to solve this problem, inorganic particles such as magnesium oxide can be surface treated with vinyl silane, stearic acid, oleic acid, aminopolysiloxane, titanate-based coupling agent, etc., preferably with vinyl silane. .

When the inorganic particles are surface-treated with vinyl silane, etc., an alkoxy group such as vinyl silane is attached to the surface of the inorganic particles, such as magnesium hydroxide, by chemical or physical bonding through hydrolysis and condensation reactions, and the surface-treated inorganic particles The particles react with the base resin to ensure excellent dispersibility.

In particular, vinyl silane, as a surface treatment agent for the inorganic particles, has an excellent effect of improving the dispersibility of the inorganic particles compared to other surface treatment agents, and at the same time, it does not deteriorate the crosslinking reaction during water crosslinking of the insulating composition and improves the insulating layer (20 ,30) is desirable in terms of implementing stable insulation resistance. The advantage of vinyl silane as a surface treatment agent for the inorganic particles, especially the advantage of realizing stable insulation resistance of the insulation layers (20, 30), is that the insulation resistance of the insulation layers (20, 30) is reduced by the polar group of the external lubricant, which will be described later. Its importance may become more pronounced in terms of offsetting this potentially deteriorating problem.

The content of the flame retardant may be an amount capable of securing sufficient flame retardancy of the insulating composition, for example, flame retardancy satisfying the standard KS C 60332-1, for example, about 100 parts by weight based on 100 parts by weight of the base resin. It may be from 180 parts by weight. If the content of the flame retardant is less than about 100 parts by weight, the flame retardancy of the insulating composition may be insufficient, whereas if the content of the flame retardant is more than about 180 parts by weight, the molding processability such as flexibility, extensibility, and extrudability of the insulating composition may be reduced. .

On the other hand, when the insulating composition forming the insulating layer 20 contains inorganic particles such as magnesium hydroxide or aluminum hydroxide as a flame retardant, temperature control is very important during extrusion to form the insulating layer 20. The temperature is preferably maintained below about 150°C. If the extrusion temperature is excessively high, the surface smoothness and physical properties of the insulating layer 20 may deteriorate due to the dehydration process.

The insulating composition forming the insulating layer 20 includes a cross-linking agent, so that the insulating layer 20 may be made of cross-linked polyolefin (XLPO). The crosslinking method of the crosslinked polyolefin (XLPO) forming the insulating layer 20 is not particularly limited. For example, the polyolefin is continuously extruded in a high temperature and high pressure steam pipe in a short period of time at the same time as the extrusion molding of the insulating layer 20. There is a chemical crosslinking method for crosslinking, a water crosslinking method for crosslinking polyolefin at low temperature and normal pressure over a long period of time after extrusion molding of the insulating layer, and an irradiation crosslinking method for crosslinking polyolefin by separate electron irradiation after extrusion molding.

However, as a crosslinking method for the crosslinked polyolefin (XLPO), the chemical crosslinking method has the problem of requiring additional equipment and costs because the crosslinking is performed in a high-temperature and high-pressure steam pipe, and the irradiation crosslinking method has problems such as flame retardancy of the insulating layer, insulation resistance, etc. Since there is a problem that may cause deterioration, the water cross-linking method is preferable.

Here, the crosslinking agent is an organic silane such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltrimethoxyethoxysilane in the case of water crosslinking according to the crosslinking method of the polyolefin, and preferably has high reactivity to increase crosslinking efficiency. Especially excellent vinyltrimethoxysilane, or in the case of chemical crosslinking, dicumyl peroxide, benzoyl peroxide, lauryl peroxide, t-butyl cumyl peroxide, di(t-butyl peroxy isopropyl) benzene, 2,5- An organic peroxide-based crosslinking agent such as dimethyl-2,5-di(t-butyl peroxy)hexane and di-t-butyl peroxide may be used, preferably dicumyl peroxide, which is inexpensive and has particularly excellent crosslinking efficiency.

In particular, when the cross-linking agent is an organic silane such as vinyltrimethoxysilane, the base resin is grafted with vinyl silane through reaction with the cross-linking agent and cross-linked by contact with or exposure to moisture in the presence of a condensation catalyst. It can be. Therefore, the insulating composition may further include an appropriate condensation catalyst for water crosslinking of the base resin.

The condensation catalyst includes metal carboxylates such as dibutyltin dilaurate, tin octoate, tin acetate, lead naphthenate, and zinc octoate, titanium esters and chelates, organometallic compounds such as tetrabutyl titanate, and ethylamine. , organic bases such as hexylamine and piperidine, or acids such as inorganic acids and fatty acids, and the content of the condensation catalyst may be 0.01 to 0.2 parts by weight based on 100 parts by weight of the base resin.

Additionally, the content of the crosslinking agent may be selected so that the gel fraction of the insulating composition after crosslinking is 50 to 90%. If the gel fraction after crosslinking of the insulating composition is less than 50%, the degree of crosslinking may be insufficient and the heat resistance, hotset, etc. of the insulating composition may be insufficient. On the other hand, if it is more than 90%, the degree of crosslinking is excessive and may be insufficient when extruding the insulating composition. Scorch may occur due to premature crosslinking. The content of the cross-linking agent may be, for example, 0.5 to 5 parts by weight based on 100 parts by weight of the base resin.

The insulating composition forming the insulating layer 20 may further include other additives such as antioxidants, internal lubricants, moisture absorbents, processing stabilizers, heavy metal deactivators, foaming agents, and multifunctional monomers.

The antioxidant functions to inhibit oxidation of the polymer resin contained in the insulating composition, and is, for example, a phenol-based, amine-based, or quinone-based antioxidant, preferably a phenol-based antioxidant or amine-based antioxidant. May contain preventive agents. Here, as the antioxidant, the phenol-based antioxidant is more effective in suppressing discoloration of the internal lubricant in the insulating composition, and the amine-based antioxidant can further improve the insulation resistance of the insulating layer formed by the insulating composition. You can.

Depending on the temperature of the insulating composition, the solubility of the antioxidant in the polymer resin may vary greatly. Specifically, as the temperature of the insulating composition decreases, the solubility of the antioxidant decreases, and therefore, the insulating composition After extrusion molding, when crosslinking at a relatively lower temperature than the extrusion temperature, the solubility of the antioxidant is greatly reduced, and the antioxidant is eluted to the surface of the insulating layer (20, 30) or the internal lubricant is also eluted during the elution, resulting in blooming. (blooming) phenomenon may be caused.

In addition, the blooming phenomenon is a particular problem when the insulating composition contains an external lubricant, which will be described later, because the external lubricant is an antioxidant in the process of moving to the surface of the insulating layer 20, 30 due to its polar group. , it is presumed that this is because it moves together with internal lubrication agents.

Meanwhile, when the melting point of the antioxidant is below the crosslinking temperature +5°C of the insulating layer, preferably below the crosslinking temperature, the blooming phenomenon on the surface of the insulating layer 20 and 30 may be significantly reduced. Here, the crosslinking temperature of the insulating layer may vary depending on the crosslinking method of the insulating layer, and in the case of water crosslinking, the crosslinking temperature may be about 70 to 100°C.

Predictably, if the melting point of the antioxidant is below the crosslinking temperature of the insulating layer +5°C, for example, if the insulating layer is formed by water crosslinking and the melting point of the antioxidant is below 90°C, the insulating layer ( 20,30) When the insulation composition is extruded and then crosslinked to form the antioxidant, the phase of the antioxidant changes from a solid phase to a liquid phase and adheres to the polymer resin, suppressing elution, so the blooming phenomenon appears to be suppressed. .

Accordingly, the insulating composition forming the insulating layers 20 and 30 may include an antioxidant whose melting point is lower than the crosslinking temperature of the insulating layers 20 and 30. Based on 100 parts by weight of the base resin, the content of the antioxidant may be 0.05 to 5 parts by weight. Here, if the content of the antioxidant is less than 0.05 parts by weight, the anti-oxidation performance of the insulating layer is insufficient, whereas if it is more than 5 parts by weight, the anti-oxidation performance does not converge and is not further improved, and the insulation resistance may decrease.

In addition, the internal lubricant may include a hydrocarbon-based wax, for example, a paraffin-based wax or an olefin-based wax, or a fatty acid-based, fatty acid amide-based, ester-based, or silicone-based internal lubricant, and is preferably used as the base resin. It may contain paraffin wax or olefin wax, which has particularly excellent compatibility with olefin resins, and functions to improve compatibility between the polymer resin and other additives included in the insulating composition.

The content of the internal lubricant may be about 0.3 to 7 parts by weight based on 100 parts by weight of the base resin. If the content of the internal lubricant is less than about 0.3 parts by weight, the compatibility of the polymer resin with other additives may be greatly reduced. On the other hand, if it exceeds 7 parts by weight, the mechanical properties and heat resistance of the insulating layer formed by the insulating composition may be greatly reduced.

In addition, the moisture absorbent may be calcium oxide, calcium chloride, silica gel, activated alumina, etc., and functions to suppress the deterioration of physical properties due to the generation of bubbles during extrusion of the insulation composition by absorbing moisture in the insulation composition. The content of the desiccant may be about 0.1 to 3 parts by weight based on 100 parts by weight of the base resin. If the content of the desiccant is less than 0.1 part by weight, the effect of adding the desiccant may be minimal, whereas if it exceeds 3 parts by weight, the effect of adding the desiccant may be minimal. The electrical properties of the insulating composition may deteriorate.

The insulating composition forming the insulating layer 20 or the insulating outer layer 30 may further include an external lubricant and a pigment. The external lubricant has a polar group in its molecular structure and moves to the surface of the insulating layer (20, 30) formed by the insulating composition, thereby lowering the coefficient of friction of the surface and improving the laying properties of the insulated wire. , the pigment serves to impart color to the surface of the insulated wire.

Specifically, as shown in FIG. 2A, when the wire includes only the insulating layer 20 and does not include a separate insulating outer layer 30, the insulating layer 20 has a certain thickness from its surface, e.g. For example, the external lubricant and/or pigment may be included 50 to 500 ㎛ radially inward.

Meanwhile, as shown in FIG. 2b, when the wire includes an insulating layer 20 and one or more insulating outer layers outside the insulating layer 20, the outer lubricant is applied to the insulating outer layer 30 as the outermost insulating layer. and/or pigments may be included.

In particular, the insulating composition forming the insulating layer 20 or the insulating outer layer 30 is an environmentally friendly non-halogen-based base resin that replaces the polyvinyl chloride (PVC) resin that forms the insulating layer of conventional insulated wires for indoor wiring. Since a polyolefin resin, for example, a mixed resin of low density polyethylene (LDPE) and polyolefin elastomer (POE) is applied, the flame retardancy of the non-halogen-based polyolefin resin, which is inferior to the polyvinyl chloride (PVC) resin, is improved. Therefore, a large amount of flame retardant must be added, and a problem arises in which the surface smoothness of the insulating layer 20 or the insulating outer layer 30 formed as a result is deteriorated. To solve this problem, an external lubricant can be added to the insulating composition. However, if the content of this external lubricant exceeds a certain level, the surface of the insulating layer 20 or the insulating outer layer 30 becomes excessively slippery, causing localized areas during the extrusion process of the insulating layer 20 or the insulating outer layer 30. Since the outer diameter may be uneven, which may result in the outer diameter being thick or thin, the content of the external lubricant must be precisely controlled.

That is, the external lubricant reduces the surface friction coefficient of the insulating layer 20 or the insulating outer layer 30, thereby improving the laying properties of the insulated wire and at the same time, the insulating layer 20 or the insulating outer layer 30. It can be added in an amount that does not cause external diameter unevenness during the extrusion process.

Specifically, the external lubricant is the surface friction coefficient of the insulating layer 20 or the insulating outer layer 30 containing the external lubricant, and that of another insulating layer of the same prescription except that the external lubricant is not included. Based on the surface friction coefficient, it can be added in an amount that can quantifiablely reduce it by more than 15%.

For example, based on 100 parts by weight of the base resin of the insulating composition forming the insulating layer 20 or the insulating outer layer 30, the content of the external lubricant is 0.3 to 10 parts by weight, preferably 1 to 5 parts by weight. parts, and the content of the pigment may be 0.5 to 5 parts by weight.

If the content of the external lubricant is less than 0.3 parts by weight, the surface friction coefficient of the insulating layer 20 or the insulating outer layer 30 cannot be sufficiently lowered, and if it exceeds 10 parts by weight, not only the unit cost of the wire is improved, but also the friction force is reduced. Excessive reduction may result in uneven outer diameter, where the outer diameter of the wire becomes thicker or thinner locally during the extrusion process.

Furthermore, as shown in Figure 2b, when the non-halogen-based flame retardant polyolefin cross-linked insulated wire according to the present invention includes an insulating layer 20 and a separate insulating outer layer 30 disposed on the outside thereof, the insulating outer layer ( The total content ratio of the internal lubricant and the external lubricant contained in the insulating outer layer 30 to the content of the base resin contained in 30) is the ratio of the total content of the base resin contained in the insulating layer 20 to the content of the base resin contained in the insulating layer 20. It may be greater than the total content ratio of the internal lubricant and the external lubricant included in .

External lubricants that lower the friction coefficient of the insulating layer 20 or the insulating outer layer 30 formed from the insulating composition to improve the laying properties of electric wires containing them, pigments that give them a desired color, other additives, etc. Silver can usually be added in powder or liquid form, and to further improve compatibility with the base resin, a resin that is the same or different from the base resin is used as the main raw material of the vehicle, and external lubricants, pigments, additives, etc. are added to it. It can be added in the form of a masterbatch, which is a raw material in the form of pellets that are concentrated and dispersed at a high concentration.

Here, the vehicle can be defined as containing all ingredients except the main ingredient in the masterbatch. For example, in an external lubricant masterbatch, the vehicle can be defined as including all resins and other additives except the external lubricant, and in a pigment masterbatch, the vehicle can be defined as including all resins and other additives except the pigment.

Additionally, the vehicle included in the masterbatch may be included in an amount that allows the insulated wire according to the present invention to satisfy the flame retardancy of the KS C IEC 60332-1 standard. If the content of the vehicle included in the masterbatch is excessive, the content of the portion of the insulating composition excluding the flame retardant increases relatively, so flame retardancy may be reduced.

The external lubricant is a compound having a polar group such as hydroxyl group (-OH) and carboxyl group (-COOH) in its molecular structure, and may include, for example, fatty acid, fatty acid salt, fatty acid amide, silicone-based lubricant, special grade wax, etc., In addition to the function of lowering the surface friction coefficient of the insulating layer 20 or the insulating outer layer 30, the elongation is further improved to cause damage to the insulating layer 20 or the insulating outer layer 30 in the bending area when the wire is bent. avoids or minimizes, and furthermore, the external lubricant additionally performs the function of suppressing insulation destruction caused by water permeability when the electric wire is submerged.

The external lubricant may be added in the form of a masterbatch or directly to the insulating composition forming the insulating layer 20 or the insulating outer layer 30. When the external lubricant is added in the form of a masterbatch, it may be included in the masterbatch in an amount of 40 to 60% by weight based on the total weight of the masterbatch. In addition, the pigment master batch (CMB) may be in the shape of a pellet, plate, flake, etc., and the concentration of the pigment is 20 based on the total weight of the pigment master batch. It may be from 70% by weight.

The content of the pigment may be 0.5 to 5 parts by weight, preferably 2 to 3 parts by weight, based on 100 parts by weight of the base resin of the insulating composition forming the insulating layer 20 or the insulating outer layer 30.

Here, if the pigment content is less than 0.5 parts by weight, it may be difficult to realize the desired color of the insulating layer 20 or the insulating outer layer 30, while if it exceeds 5 parts by weight, the flame retardancy and UV stability of the wire deteriorate. and the unit cost of the insulated wire may increase unnecessarily.

When the wire has only a single insulating layer 20, it is located in an area of a certain thickness from the surface of the insulating layer 20, and when it has both the insulating layer 20 and the insulating outer layer 30, the insulating outer layer 30. Since the external lubricant and the pigment are included, it exhibits a heterogeneous and unpredictable effect of significantly lowering the surface friction coefficient of the insulating layer 20 or the insulating outer layer 30, resulting in the non-halogen-based flame retardancy. It performs the function of greatly improving the laying properties of polyolefin cross-linked insulated wires, and by minimizing the content of pigments to achieve the desired color of the wires, the decrease in flame retardancy due to the addition of pigments can be minimized.

When the wire is made of a double structure of the insulating layer 20 and the insulating outer layer 30, the total thickness of the insulating layer 20 and the insulating outer layer 30 is that of the non-halogen-based flame retardant polyolefin cross-linked insulated wire. It may vary depending on the conductor standard, for example, may be about 0.7 to 1.0 mm, where the thickness of the insulating outer layer 30 may be about 50 to 500 ㎛.

In the present invention, when the thickness at which the external lubricant and the pigment are substantially included in the insulating layer 20 or the thickness of the insulating outer layer 30 is less than about 50 ㎛, the insulating layer 20 is transparent and the desired In order to realize the color of the insulating layer, an excessive amount of the pigment must be added, and if the pigment is added in the form of a pigment masterbatch, the flame retardancy of the wire may be reduced.

On the other hand, when the thickness at which the external lubricant and the pigment are substantially included in the insulating layer 20 or the thickness of the insulating outer layer 30 exceeds about 500 ㎛, it is also possible to implement the desired color and physical properties of the insulating layer. For this, a large amount of external lubricant and pigment must be added, which may deteriorate the physical properties of the wire.

The insulating composition forming the insulating outer layer 30 disposed on the outside of the insulating layer 20 is used to secure close adhesion between the insulating layer 20 and the insulating outer layer 30 and to simplify the manufacturing process. It is preferable that the insulating composition forming the layer 20 contains the same base resin, flame retardant, crosslinking agent, and other additives, and is crosslinked in the same manner.

Figure 3 is a cross-sectional view schematically showing the cross-sectional structure of another embodiment of an electric wire forming a bundle of electric wires according to the present invention. As shown in FIG. 3, the insulating layer 20 or the insulating outer layer 30 of the wire may have one or more protrusions 31. The protrusion 31 can further improve the laying properties of the electric wire by changing the surface contact between the insulating layer 20 or the insulating outer layer 30 and the inner wall of the PVC conduit during laying to line contact.

The number of protrusions 31 may be 4 as shown in FIG. 3A, 5 as shown in FIG. 3B, and 9 as shown in FIG. 3C. The number of protrusions 31 and their The arrangement can be appropriately selected by a person skilled in the art according to the specifications of the wire and working conditions during installation.

Figure 4 is a cross-sectional view schematically showing the cross-sectional structure of another embodiment of an electric wire forming a bundle of electric wires according to the present invention. As shown in FIG. 4, the wire may be formed by extruding a plurality of conductors, for example, two or three conductors simultaneously, so that their insulating layers are formed integrally. In this case, when a plurality of wires are installed together, not only can the problem of deterioration of installation performance due to friction between adjacent wires be solved, but also one or more protrusions 31 may be formed on the insulating layer 20 or the insulating outer layer 30 formed integrally. ) is placed so that the surface contact between the wire and the inner wall of the PVC conduit can be changed to line contact, thereby further improving the laying properties of the wire.

Figure 5 schematically shows a virtual laying work environment used when measuring the static friction coefficient and dynamic friction coefficient to evaluate the laying properties of wires forming a bundle of wires according to the present invention.

As shown in Figure 5, the two strands of the wire specimen are spaced apart from each other by a certain distance, for example, 30 to 40 mm, placed on a cart made of aluminum alloy (Al5051) with a surface roughness (R _a ) of 0.2 ㎛ or less, and the specimen With a load of 2.4 kg applied on the two strands, one end of each of the two specimen strands is fixed to a force measurement sensor, and the cart is pulled at a speed of 1.0 mm/s to the opposite side of the force measurement sensor. By measuring the force applied to the force measurement sensor due to friction between the two strands of the specimen and the cart, the static friction coefficient and dynamic friction coefficient of the specimen with respect to the material of the cart can be measured to indirectly evaluate the laying properties of the wire. .

For reference, surface roughness (R _a ), which is a surface roughness parameter indicating surface roughness based on standard KS B 0601, is the average value of the absolute length from the center line to the surface cross-section curve in the roughness cross-section curve, and the static friction coefficient and the above The friction coefficient is measured 5 times per second (5 times/s), and the highest friction coefficient after the cart starts moving is taken as the static friction coefficient. The static friction coefficient is measured for 3 seconds 3 seconds after it is measured. The average of the friction coefficients was taken as the dynamic friction coefficient.

However, measurement results corresponding to measurement errors, that is, measurement data in which there is no peak representing the static friction coefficient, the dynamic friction coefficient appears to be greater than the static friction coefficient, or the dynamic friction coefficient does not converge and gradually increases or decreases. Measurement data, measurement data in which one or more additional peaks exist before the largest peak representing the static friction coefficient, and the wire specimen being measured is excessively large due to damage to the surface during transportation or contamination of foreign substances such as oil. or measurement data showing a small friction coefficient are excluded from the measurement results.

As a result of measuring the static friction coefficient and dynamic friction coefficient of the electric wire under a virtual laying environment hundreds of times, the present inventors found that the static friction coefficient and dynamic friction coefficient of the electric wire measured by the laying environment were very accurate for the actual laying of the electric wire. Since it was confirmed that this was reflected, the static friction coefficient and dynamic friction coefficient of the wire measured by the above evaluation method show very high reliability.

Under the virtual laying work environment as shown in Figure 5, the static friction coefficient according to the method for evaluating the laying properties of the electric wire may be 0.40 or less, preferably 0.19 to 0.35, and the dynamic friction coefficient may be 0.28 or less, preferably It may be 0.16 to 0.25. Here, if the static friction coefficient is greater than 0.40 or the dynamic friction coefficient is greater than 0.28, the laying performance of the electric wire may be insufficient and the laying work of the electric wire may be inefficient. On the other hand, if the static friction coefficient is less than 0.19 or the dynamic friction coefficient is If is less than 0.16, the packaging process of the wire bundle 100 may be extremely difficult and transportability and workability may be extremely reduced.

[Example]

1. Manufacturing example

After forming a bundle of wires with the specifications shown in Table 1 below in a cylindrical shape as shown in Figure 1a with a 300 m wire specimen having a conductor and an insulating layer containing an external lubricant to surround the conductor and lower the surface friction coefficient, , 100 of the wire bundles were stacked in multiple stages on the top of the pallet as shown in Figure 1b, and the wire bundle and the pallet were wrapped together four times with heat shrink tube (thickness 0.08 mm) and packaged.

Conductor diameter (㎟) Bundle height (mm) Bundle outer diameter (mm) Bundle thickness (mm) Example 1 1.5 64 310 55 Example 2 2.5 81 320 60 Comparative Example 1 1.5 101 280 40 Comparative Example 2 2.5 102 300 50

2. Transportability evaluation

After transporting the packaged wire bundles according to each of the examples and comparative examples along the transport route as shown in Figure 6, the wrapped heat shrink tube was dismantled to check whether the pillars of the wire bundle were tilted or collapsed. . Specifically, the total transportation distance during transportation was about 5.7 km, the average moving speed was 60 to 70 km, and the moving speed in sharp curves was about 30 km. The evaluation results are shown in Table 2 below.

Evaluation results Example 1 No tilt Example 2 No tilt Comparative Example 1 tilted Comparative Example 2 tilted

As shown in Table 2, when packaging and transporting 100 wire bundles of Examples 1 and 2, in which the specifications of the wire bundle were precisely controlled, the shape of the wire bundle was maintained without being deformed by shaking or impact, resulting in It was confirmed that the columns of the multi-layered wire bundles did not tilt or collapse when the packaging was dismantled after transport, showing excellent transportability and workability.

On the other hand, when 100 wire bundles of Comparative Examples 1 and 2 are packaged and transported, the wire bundles are deformed due to shaking or impact, and as a result, the pillars of the multi-layered wire bundles are tilted when the packaging is dismantled after transport. It was confirmed that transportability and workability were poor.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims described below. You can do it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be considered to be included in the technical scope of the present invention.

100: bundle of wires 200: pallet

Claims (18)

A bundle of wires comprising a conductor and an insulating layer containing an external lubricant for lowering the surface friction coefficient while surrounding the conductor and a pigment for imparting color,
The external lubricant and the pigment are included in a range of 50 to 500 ㎛ radially inside the insulating layer,
The surface friction coefficient of the insulating layer is 0.16 to 0.40,
The relationship between the height (h) and thickness (w) of the bundle of wires is defined in Equation 1 below,
[Equation 1]
h≤1.5w
A bundle of wires, characterized in that the nominal cross-sectional area (d) of the conductor of the wire, the height (h) and the outer diameter (D) of the bundle of wires satisfy the conditions according to Equations 2 and 3 below.
[Equation 2]
h=ad
In Equation 2 above,
a is 20 to 50.
[Equation 3]
D=bh+c
In Equation 3 above,
b is 0.4 to 0.6, and c is 250 to 300. A bundle of wires comprising a conductor and an insulating layer surrounding the conductor,
The insulating layer is composed of multiple layers, and the outermost layer of the insulating layer includes an external lubricant to lower the surface friction coefficient and a pigment to impart color,
The thickness of the outermost layer of the insulating layer is 50 to 500 ㎛,
The surface friction coefficient of the outermost layer of the insulating layer is 0.16 to 0.40,
The relationship between the height (h) and thickness (w) of the bundle of wires is defined in Equation 1 below,
[Equation 1]
h≤1.5w
A bundle of wires, characterized in that the nominal cross-sectional area (d) of the conductor of the wire, the height (h) and the outer diameter (D) of the bundle of wires satisfy the conditions according to Equations 2 and 3 below.
[Equation 2]
h=ad
In Equation 2 above,
a is 20 to 50.
[Equation 3]
D=bh+c
In Equation 3 above,
b is 0.4 to 0.6, and c is 250 to 300. delete delete According to claim 1 or 2,
A bundle of wires, characterized in that the elastic modulus of the conductor is 15,000 to 21,000 MPa. According to claim 1 or 2,
A bundle of wires, characterized in that the conductor is a single wire. delete According to claim 1 or 2,
A bundle of wires, characterized in that the bundle of wires is bound by binding means at 4 to 6 points to maintain its shape. According to claim 1 or 2,
The bundle of wires has a height (h) of 60 to 70 mm and a thickness (w) of 50 to 60 mm when the nominal cross-sectional area (d) of the conductors of the wires is 1.5 mm2, and the nominal cross-sectional area of the conductors of the wires is A bundle of wires, characterized in that the height (h) is 75 to 85 mm and the thickness (w) is 55 to 65 mm when (d) is 2.5 mm2. According to claim 1 or 2,
The bundle of wires has a height (h) of 60 to 70 mm, an outer diameter (D) of 290 to 330 mm when the nominal cross-sectional area (d) of the conductors of the wires is 1.5 mm2, and a nominal cross-sectional area of the conductors of the wires A bundle of wires, characterized in that the height (h) is 75 to 85 mm and the outer diameter (D) is 300 to 340 mm when (d) is 2.5 mm2. According to claim 1 or 2,
A bundle of wires, characterized in that a is 25 to 45, b is 0.5 to 0.6, and c is 265 to 270 in Equations 3 and 4. Step of stacking the bundle of wires of paragraph 1 or 2 in multiple stages on the top of the pallet; and
A packaging method for a bundle of wires, comprising the step of wrapping the bundle of wires stacked in multiple stages with a packaging member at least once. According to clause 12,
A method of packaging a bundle of wires, characterized in that it further comprises the step of inserting a friction increasing member between the ends when stacking the bundle of wires in multiple stages. According to clause 13,
A method of packaging a wire bundle, wherein the friction increasing member is paper. According to clause 12,
A method of packaging a wire bundle, wherein the packaging member is a heat shrink film. According to clause 12,
A packaging method for a bundle of wires, characterized in that the pallet and the bundle of wires stacked in multiple stages are entirely wrapped. According to clause 12,
A packaging method for a wire bundle, characterized in that wrapping 1 to 6 times with the packaging member. According to clause 15,
A method of packaging a wire bundle, characterized in that the thickness of the heat shrinkable film is 0.01 to 0.2 mm.

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