Steel cord has many excellent mechanical properties. Compared with nylon cord, its strength is 4:1, the fatigue resistance of 420:10, and impact resistance energy of 330:20. Steel cord is widely used as the reinforcing material of automobile tires in various countries in the world, and it is widely used in transportation belt, toothed belt, high pressure hose, escalator handrail and other rubber products.

As the reinforcing material of tire and other rubber products, steel cord has obvious advantages over cotton fiber, polyester fiber, nylon silk, viscose silk and other fabrics, including:

1. Steel cord is 4 times stronger than nylon cord and 6 times stronger than rayon cord. Meanwhile, the steel wire tensile strength of the thermal stability is excellent. When tires are up to the normal operating temperature of the tire (about 120℃), steel wire can maintain the original strength of about 95%, but nylon and rayon is 85% and 70% respectively. Moreover, steel cord is the only skeleton material with a definite fatigue limit.

2. Steel cord has much better thermal conductivity than other fabrics. Because of its good thermal conductivity, it is used as a skeleton material in high speed operation of the tire or tape produced by the heat, through the conduction of steel cord, easy to send out.

3. Steel cord has much higher dynamic elasticity than other fabrics and better impact resistance. Moreover, the tensile creep is smaller and the size is stable.
4. The steel cord is soft and comfortable to ride on as a reinforced tire, and the conveyor belt as a reinforced material can run on rollers of very small diameters.

So the selection of steel cord as the framework material should be in line with the tire high speed, high load, durability of high quality lightweight requirements.

The structural development trend of steel cord is shown in the following aspects:

1. The diameter of monofilament is thicker and the structure is simplified.

2. Improving the strength of steel cord and developing high strength cord

3. Developing open cord

4. Applying compact cord

5. Developing high elongation cord

Introduction of production equipment of steel cord

1）Coarse and middle drawing for the straight - forward type wire drawing machine, using AC frequency conversion speed regulation, drum and mold using water cooling, rough drawing machine drawing speed up to 15m/s, middle drawing machine drawing speed up to 18m/s, high production efficiency, stable steel wire performance.

2）The heat treatment of medium wire adopts isothermal lead quenching, and the heating of maffer furnace and lead cylinder adopts gas. This production line has high thermal efficiency.

3）The steel wire electroplating adopts thermal diffusion electroplating, the heat treatment of steel wire is combined with thermal diffusion electroplating of brass, muff furnace, lead cylinder and thermal diffusion boiling furnace are all heated by gas.Electroplating production line, the first adopts the pyrophosphate copper plating, and then USES sulfate copper plating, and then in sulfate zinc, final reoccupy fluidized bed particle heating method for metallographic thermal diffusion, let the zinc atom diffusion of copper atoms, form the alpha brass, each wire single flow control, steel wire machinery and the coating quality of uniform, stable and reliable.

4）The single wire drawing adopts the sliding water tank wire-drawing machine, adopts the ac motor frequency conversion speed regulation, the drawing time is 25, the maximum drawing speed is 25m/s, the winding tension, the production efficiency is high.
5）The twister is a double twister, which adopts ac motor frequency control and chain friction to control the tension of steel wire and strand.

Bonding properties of steel cord and rubber

One of the most important properties of steel cord is its adhesion to rubber.

The adhesive property has two representations: one is expressed by adhesive force, which refers to the force needed to pull the cord from the rubber ingredients, also known as extraction force, expressed by Newton (N);The other one is expressed by adhesive level, that is, cord surface adhesive degree after cord extracted from the rubber ingredients.

Steel wire and rubber are two completely different materials with almost no adhesive force between them. Only the steel wire surface coated with copper, zinc, bronze (copper-tin alloy), brass (copper-zinc alloy), can rubber have different degrees of adhesion, in which brass coating and rubber adhesion is the best.