KR20000034634A - Steel cord for reinforcing rubber product - Google Patents

Abstract

PURPOSE: A steel cord for reinforcing a rubber product is provided to have a low elongation of low load, to improve the osmosis of rubber and to be easily produced. CONSTITUTION: An one strand among three strands of early filament of steel cord gives a change onto a surface of filament by passing a roller of saw tooth(1) of small changed degree. Another one strand gives the change by passing a roller of saw tooth(2) of large changed degree. The other one strand gives a final twisting by doubling a yarn in a straight state. Thereby a regular interval from 0.1mm to 2.0mm is periodically given into each filament. A changing pitch(P2) of small changed degree passed the saw tooth roller(1) of small changed degree is 0.1-0.5times of filament twisting pitch(P1) and a change pitch(P3) of filament passed the saw tooth roller(2) of large changed degree is 0.2-1.0times of filament twisting pitch(P1). A changed diameter(D2) of filament passed the saw tooth roller(1) of small changed degree is 1.1-3.0times of a filament diameter(D1) and a changed diameter(D3) of filament passed the saw tooth roller(2) of high changed degree is 1.4-5.0times. The changed pitch and the changed diameter of filament are controlled by changing a pitch and a groove of saw tooth roller.

Description

Steel cord for rubber product reinforcement

The present invention relates to a steel cord for reinforcing rubber products, wherein, in a steel cord consisting of 3 to 6 strands of filaments, the strain rate is different for each filament through two or more types of toothed rollers having different strain rates for the filaments only for 2 to 5 strands before twisting. The present invention relates to a steel cord for reinforcing rubber products having low elongation at lowering and improving rubber penetration.

The steel cord is coated with 0.1 to 0.4 μm thick brass on a 0.1 to 0.4 mm diameter wire made of carbon steel with a carbon content of 0.6 to 0.95% by weight. 3, 1 × 4, 2 + 2, 2 + 7, 3 + 6, 3 + 9 + 15, etc.), and has excellent strength, modulus, heat resistance, and fatigue resistance compared to other inorganic and organic fibers. It is used to reinforce rubber products such as conveyor belts.

Since steel cords are used as reinforcement materials for tires, they must have excellent adhesion to rubber, which is a heterogeneous material, and excellent durability is required for the harsh environment that a vehicle forms during driving.

To cope with this, the steel cord industry and the tire industry have conducted a lot of research to improve these properties. In terms of steel cords, studies on plating layers involved in adhesion with rubber, studies on stranded wire structure of steel cords, and studies to improve adhesive strength by changing rubber composition of tires have been conducted. Is a study on

The structure of general steel cord is manufactured by simply twisting 3 ~ 5 strands of filaments with each other and there is little gap between each filament constituting steel cord. And there is a problem that the tire durability is lowered.

U.S. Patent No. 4,258,543 proposes an open steel cord that improves the penetration of rubber by providing a uniformly high strain to the filaments constituting the steel cord, thereby widening the spacing between the filaments. -43866 proposes an open steel cord which improves the penetration of rubber by constructing a wide and non-uniform spacing between each filament.

However, these open steel cords have an elongation (low load elongation) of 0.4% or more at a load of 5 kg during the tensile test, and 2 to 5 kg acting on the steel cord when working in the calendering process, which is the initial operation of embedding the steel cord into the tire. Since the length of steel cord is increased by 0.3 ~ 0.5%, it is buried due to the elastic recovery property of steel cord. After the work, the tension in the compression direction is generated and the bending of rubber and steel cord occurs during cutting for tire processing. It is difficult to automatically connect the post-process, there is a problem that greatly inhibits the tire manufacturing workability.

In addition, Japanese Unexamined Patent Publication Nos. 2-307994, 4-50390, and 5-163687 have preformed steels, which are provided with constant deformation by passing tooth rollers before twisting specific filaments constituting steel cords. The code is shown. However, these preformed steel cords have low elongation at low loads, which improves tire manufacturing workability compared to open cords.However, the gap between each filament is less secured than open steel cords. have.

The present invention is to overcome the above-mentioned problems in the prior art, and to provide a steel cord for reinforcing rubber products, which has a low elongation while lowering the rubber penetration force and is easy to manufacture.

1 is a schematic diagram of an apparatus for manufacturing a steel cord of the present invention,

2 (A) is an enlarged view of the portion (a) of the filament in FIG.

(B) is an enlarged view of (b) partial filament in FIG.

(C) is an enlarged view of the portion (c) filament in Figure 1,

Figure 3 (A) is a cross-sectional view of a conventional 1 × 3 steel cord,

(B) is a sectional view of a conventional 1 × 3 open steel cord,

Figure 4 (A) is a cross-sectional view of the steel cord 1 × 3 structure of the present invention,

(B) is a cross-sectional view of the steel cord of 1 × 4 structure of the present invention,

(C) is sectional drawing of the 1 * 5 structure steel cord of this invention.

Explanation of Main Codes in Drawings

1: Low Strain Tooth Roller 2: High Strain Tooth Roller

That is, according to the present invention, in the steel cord composed of 3 to 6 filaments, the 2 to 5 filaments are passed through two or more types of tooth rollers having different sizes before twisting, so that the filament surface has different strain rates, and the remaining filaments Regarding the steel cord for reinforcing rubber products, characterized in that the total twist is given after weaving without imparting deformation.

Hereinafter, the present invention will be described in more detail.

Figure 1 is a schematic diagram of a manufacturing apparatus used to manufacture the steel cord of the present invention is provided with two different toothed rollers, wherein the present invention steel cord manufactured using three filaments, the initial filament three strands One strand passes through the tooth roller 1 of low strain to impart a strain as shown in FIG. 2 (c) to the filament surface, and another strand passes through the tooth roller 2 of large strain to To give the deformation as shown in (b), the remaining one strand can be prepared by giving a final twist to the straight state as shown in Fig. 2 (a) again to give the final twist, thereby narrowing the width between each filament to 0.1mm wide It can be given a regular interval up to 2.0mm.

At this time, the strain pitch P2 of the filament passing through the small strain toothed roller 1 is 0.1 to 0.5 times the filament twist pitch P1, and the strain pitch P3 of the filament passed through the tooth strainer 2 having a large strain rate. ) Is 0.2 to 1.0 times the filament twist pitch (P1).

In addition, with respect to the diameter (D1) of the filament, the deformation height (D2) of the filament passing through the low strainer roller (1) is 1.1 to 3.0 times, and the deformation height of the filament passing through the tooth strainer (2) of high strain rate ( D3) is 1.4-5.0 times. Here, the strain pitch and strain wave height of the filament can be adjusted by changing the pitch of the feed roller and the depth of the groove.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are only for the purpose of explanation, and the present invention is not limited by the following Examples.

Examples 1-2

As shown in Table 1 below, while changing the strain pitch and strain height, twisted three filaments to produce a 1 × 3 structural steel cord having a pitch of 14 mm and a filament diameter of 0.30 mm, and then evaluated the physical properties. It is shown in Table 1 together.

Example 3

Deformation pitch and strain height were applied to two strands of filament, and one strain of filament was applied, and one strain of low filament was applied. The twisted pitch was 16mm and the filament diameter 0.30mm. It is shown together in Table 1 below.

Example 4

Deformation pitch and strain height were applied to the two filament strands and the low strain to the two filament strands, and twisted to produce a steel cord with a pitch of 18 mm and a filament diameter of 0.30 mm. The results are shown in Table 1 together.

Comparative Example 1

After twisting the conventional 1 × 3 structure to produce a steel cord having a pitch of 14 mm and a filament diameter of 0.30 mm, the physical properties were evaluated, and the results are shown in Table 1 together.

Comparative Example 2

After twisting a conventional 1 × 3 structure to produce an open steel cord having a pitch of 14 mm and a filament diameter of 0.30 mm, the physical properties thereof were evaluated and the results are shown in Table 1 below.

Comparative Example 3

The preform is given to one strand of a conventional filament, twisted 1 × 3 structure to produce a preformed steel cord having a pitch of 14 mm and a filament diameter of 0.30 mm, and then evaluated for physical properties. The results are shown in Table 1 together.

Physical property measurement method used in the present invention is as follows.

1) Elongation at low

A general tensile tester was used and the length of steel cord extension was evaluated as a percentage in the tensile load range of 0.2kg to 5.0kg.

2) rubber adhesion

ASTM D-2229 was applied, and the applied compound used Korean A tire rubber.

3) rubber permeability (CC / min)

After the steel cord was vulcanized with rubber, a rubber block sample (length 14 mm) was prepared, and the compressed air was blown to one end of the steel cord to evaluate the amount of air coming out from the opposite side.

In addition, in Table 1

P1: twisted pitch of core cord, D1: cord diameter of core cord,

P2: Side cord twisting pitch, D2: Steel cord diameter

When the long and short diameters of the core cord and steel cord are present, both the long and short diameters are marked.

Steel cord structure Strain Lowered elongation rate Rubber adhesion Rubber penetration Comparative Example 1 General steel cord 1 × 3 × 0.30 mm P1 = 14mm D1 = 0.3mm 0.1% 25 35 Comparative Example 2 Open Steel Cord 1 × 3 × 0.30 mm P1 = 14mm D1 = 0.3mm 0.5% 35 0 Comparative Example 3 Preformed Steel Cord 1 × 3 × 0.30mm1 Strand Preformed P1 = 14mm P2 = 0.25P1D1 = 0.3mm 0.1% 28 26 Example 1 1 × 3 × 0.30 mm P1 = 14mm P2: 0.25 P1P3: 0.50 P1D1 = 0.3mm D2: 1.8 D1 D3: 3.6 D1 0.2% 34 One Example 2 1 × 3 × 0.30 mm P1 = 14mm P2 = 0.30 P1P3: 0.60 P2D1 = 0.3mm D2: 2.0 D1 D3: 4.0 D2 0.3% 37 0 Example 3 The present invention 1 × 4 × 0.30 mm 2 strands less strain 1 strand larger strain imparting P1 = 16mm P2 = 0.30 P1P3: 0.60 P2D1 = 0.3mm D2: 2.0 D1 D3: 4.0 D2 0.2% 49 2 Example 4 1 x 5 x 0.30 mm P1 = 18mm P2 = 0.30 P1P3: 0.60 P2D1 = 0.3mm D2: 2.0 D1 D3: 4.0 D2 0.3% 60 0

As described above, the filament is passed through two or more types of tooth rollers of different sizes to have a constant strain rate, and the filament that is deformed to the filament surface and the filament that is not deformed are twisted to give a predetermined interval between the filaments. It is possible to facilitate the penetration of tire rubber between the gaps, so that the fritting does not occur due to the friction between the filaments during use after the tire is manufactured, and the fatigue life is excellent, and the service life of the tire is extended. Has

In addition, the filament that does not pass through the toothed roller of the filament has a small elongation, thereby reducing the elongation during deterioration, thereby improving the tire manufacturing workability compared to the open steel cord.

Therefore, the steel cord of the present invention has a wide range of use for reinforcing rubber products such as high pressure hoses, conveyor belts as well as tire applications.

Claims (3)

In steel cords consisting of 3 to 6 strands of filaments, 2 to 5 strands of filaments are passed through two or more kinds of toothed rollers of different sizes before twisting, and have different strains on the surface of the filaments, and the remaining filaments do not impart deformation. Steel cord for reinforcing rubber products, characterized in that the final twist is given after weaving. The strain pitch P2 of the filament which gave the small strain to the filament before twisting among the different strains is 0.1 to 0.5 times the filament twist pitch P1, and the strain wave height D2 of the filament is the filament diameter D1. Steel cord for reinforcing rubber products, characterized in that 1.1 to 3.0 times larger than). The method of claim 1, wherein the strain pitch (P3) of the filament giving a large strain to the filament before twisting of the different strain rate is 0.2 to 1.0 times the filament twist pitch (P1), the filament strain peak (D3) is the diameter of the filament (D1 Steel cord for reinforcing rubber products, characterized in that 1.4 to 5.0 times larger than).