Power cable production with double twist buncher

Dear all,

Has anyone experienced the use of double twist buncher (i.e. 1600/2000 mm) for strand production (i.e. 7x2,6mm; 7x2,9mm) in aluminum alloys 8030, in particularly if it is necessary annealing the wire after wire drawing before bunching process ?

Thanks a lot for your help

Enrico Conte

Hello Enrico,

What I am familiar with is aluminum Milliken conductor for these very large conductors and they are used with EHV cable.

When extruding EHV cable, the most important thing is to guarantee the roundness of the conductor for obvious reasons.

When manufacturing the Milliken strand, a rigid strander is normally used.

With 1350 aluminum conductor one need not anneal the wires however alloy wires may require annealing. The determining factor is how well the strands close to form the Milliken conductor. As is normal practice, copper wires should be annealed.

I would be surprised if a double twist strander/ buncher could properly make the strands for a large Milliken conductor.

Hi Peter, thanks for your reply.

Regarding the aluminium stranding, we're familiar in use a double twist buncher up to 50sqmm compacted strand (ex. 7x2,9mm) in Al99,5 or Al1350. Now I would upgrade the application with Al8030 but I'm wondering about the material behaviour.
In particular, I'm not sure if the wire after wiredrawing we need an annealing process (in line i think is better) or not, considering the stress during compacting operation

Thanks for your help again

Enrico Conte

We make up to 95mm² in 18 or 19 wire unilay construction. Annealing is always good if you are compacting the conductor. By using gathering die outside then compression rollers and last PCD finishing die inside before capstan you can easily do it with AAAC. Recently i supplied 70mm² hard drawn Cu also in semi compaction, no problem with process but the shape was hexagonal.

Dear Enrico:

Please, check the brochure of SOUTHWIRE about their "TRIPLE E". Here speak about AA8176 but in my opinion is the same to your 8030. For technical requeriments, please consult:

1.-B800: Standard Specification for 8000 Series Aluminum Alloy Wire for Electrical Purposes - Annealed and Intermediate Tempers1
2.-B836 Standard Specification for Compact Round Stranded Aluminum Conductors Using Single Input Wire construction1


www.southwire.com/products/TripleeOEM.htm


Best Regards,





Juan Carlos del Rey Menéndez