Precautions for steel core aluminum stranded wire – news

Precautions for steel core aluminum stranded wire – news

1. Greasy dirt on the wire surface

Steel-cored aluminum stranded wires for overhead transmission lines are often questioned by customers or even returned due to surface quality problems. This phenomenon is mainly caused in the drawing process. The main reasons are as follows:

(1). The size of the finished wire drawing die is too large, the compression is relatively small, the working area of ​​the wire drawing die is shorter, and the oil on the surface of the wire is not removed;

(2). the temperature of the lubricating grease is too low, the viscosity is large, and it is not easy to play, causing the drawing oil to adhere to the surface of the aluminum wire;

(3). the thread rubbing felt at the outlet of the finished mold is too dirty;

(4). When twisting the wire, the stranding machine body or the traction wheel is too dirty;

(5). There is too much water under the traction wheel.

For the above reasons, in order to avoid the generation of oil stains on the wire surface, you should choose a suitable wire drawing die and adjust the lubricating grease temperature when drawing; frequently change the wire rubbing felt, and keep the stranding equipment and mold clean and free of oil when stranding the wire.

2. The wire surface is scratched

Because there are metal sharp objects in the wire drawing equipment and the wire drawing die or the wire stranding equipment and the stranding die, it is easy to cause surface scratches when the wire is drawn or the wires are stranded. This kind of defect firstly affects the surface quality of the wire, and secondly, corona occurs due to the unevenness of the conductor when the wire is running. Therefore, once the surface scratches are found, the cause should be investigated from the equipment or mold.

3. Wire scratches

Continuous scratches on wires are a common cause of corona, and corona is one of the important causes of power loss in the power system. In order to avoid the occurrence of wire scratches, the following aspects should be controlled in the production: first consider the conductor itself, the aluminum rod is not damp, and the aluminum rod is damp, causing aluminum chips to stay in the working area of ​​the drawing die hole, and lubricating oil cannot enter the working area. , Resulting in the drawn aluminum wire is not round and not smooth. The drawing oil should be clean and moisture. As the drawing oil enters the working area from the lubrication area during the drawing process, it is at a high temperature. If it contains moisture, the lubricating oil will be diluted and the lubrication effect will be greatly reduced, resulting in wire scratches and aluminum wire breaks.

Secondly, from the perspective of production, the following issues should be paid attention to:

In the drawing process:

(1). Check whether the mold of the wire drawing machine is placed accurately;

(2). Check whether the drawing drum has a groove after friction, and whether there is a crimping phenomenon;

(3). Check whether the surface finish of the lubrication area of ​​the drawing die meets the requirements, and whether there is blockage by aluminum chips.

Stranding process:

(1) Check the spool to rotate sensitively;

(2) Check whether the tension of the spool is uniform;

(3) Check whether the single wire is slightly crimped or the wire is uneven;

(4) Check whether the single wire is in the groove of the guide wheel during twisting.

4. Loose wires and serpentine bends

(1) When the wire is twisted, the tension of the wire reel should be adjusted. The tension depends on the experience accumulated in the usual work. Generally, experienced operators should be able to adjust the tension to the appropriate requirements;

(2) When selecting the parallel wire mode first, the diameter of the parallel wire mode is required to be smaller than the outer diameter of the stranded wire. 3—.5mm;

(3) Adjust the back-twisting device so that the single wire is “S” before twisting, so as to eliminate the internal stress generated by the single wire during the twisting process;

(4) Minimize the number of stops during the stranding process. The same stranded wire is produced at the same fixed speed, and the wire stranding pitch is different due to uneven vehicle speed or parking/driving, which causes the wire to loose;

(5) Pre-check before using the steel core for stranding, there is no loose phenomenon; when the wire is stranded, the steel core should maintain a constant pay-off tension