stranded wire
I. Characteristics of stranded wire
1. Good softness; It can reduce the damage caused by bending, vibration and swing, which is conducive to installation.
2. Good reliability: the defects of the single wire that makes up the stranded wire cannot be concentrated in the same place, so the influence of the single wire defect on the performance of the stranded wire is much weaker than that on the performance of a single conductor.
3. High strength: when using the same rod material to draw the wire, the deformation degree of the drawn thin wire is greater than that of the thick wire, so the thin wire has high strength. The strength of the stranded wire is higher than that of a single conductor with the same cross section.
II. Twisting method
There are two twisting methods for conductive wire core: without back-twisting and back-twisting.
The wire core twisted by back-twisting method has no torsion internal stress, so it is mostly used for non-tight stranded wire to avoid scattering when single wire breaks due to internal stress. The winch without back-twisting is mostly used for pressing the wire core, because the residual stress generated by self-twisting is elastic deformation, and the pressing type is plastic deformation, so the internal stress can disappear after pressing tightly.
III. Twisting direction
The twisting direction of stranded wire whether concentric stranded or complex wringing, its outermost layer is regulated as right direction (Z-shape); The outermost layer of stranded insulated wire is left direction (S-shape). Whether right or left, its two adjacent twisted directions must be opposite. This is for product unification, easy connection, and prevent single line from loose.
IV. Parallel Mode
The parallel mode is the important control point of the stranded wire: the uniformity of the diameter of the stranded wire, whether there is snake shape, lack of root, jumping phenomenon are all shown here. The parallel mode is generally composed of two semicircles. The inner hole of the steel mould is chrome plated, and it can also be made of hardwood. Practice has proved that the wood mould is more practical. The practice has proved that the wood mold is more practical, the steel mold is not only high cost, but also is to scrape the line, which is easy to make the wire core burr. The function of the parallel mode is to make the stranded wire core fixed diameter molding. Experience shows that it is appropriate that the aperture of parallel mode is slightly smaller than the calculated OD by 0.1~0.3mm.
Post time: May-08-2020