Dear Sir,

Can I please have inputs for making triple insulated wire? Are there any threads or papers where I can get the information.??

Thanks and regards,
Conins

Hello Conins,

There are many papers at the following Internet locations. You may wish to join some of these associations.

The Association of Edison Illuminating Companies (AEIC) (USA) www.aeic.org/
The Insulated Cable Engineers Association (ICEA) (USA) www.icea.net/
The Electric Power Research Institute, Inc.(EPRI) (USA) my.epri.com/portal/server.pt?
The International Council on Large Electric Systems (CIGRE) (France) www.cigre.org/
Jicable (France) www.jicable.org/

The following are the premier power cable equipment manufacturers for extrusion:

Troester GmbH & Co. KG · www.troester.de/
Maillefer Extrusion www.mailleferextrusion.com/

They should also have a number of technical documents.

Regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

You need to describe the exact product that you are looking to manufacture. 3 co extruders can be designed to apply 3 layers simutaneously but consideration must be made concerning the melt temeperature differential between polymer layers. The other method is the tandem process where each extruder is put in line one after the other allowing sufficient cooling between each application of polymer. Difficulty here is proper centering of conductors within the crosshead to prevent scraping of the polymer inside the tip of the next crosshead. Some systems can incorporate both setups. You are best suited to talk to the various crosshead manufacturers before determining the optimum line configuration.


Erik Macs
VP North American Machinery Sales
Fine International Corporation
148 Oak Street
Natick, MA 01760 USA
508-315-8200 fax: 615-658-1988
This email address is being protected from spambots. You need JavaScript enabled to view it.

A good point Erik but in so far as power cable is concerned and with more than 20 years personal experience in the manufacture of XLPE triple layer power cable from 5kV to more than 230kV, I can tell you that I am not aware of anybody still using 1+1+1 or even 1+2 extruder configurations. The reasons are exactly what you said re mechanical damage to the layers plus of course inter-layer contamination. (dust and dirt)

Mechanical damage to the layers and inter-layer contamination significantly reduces the life of the cable.

With regard to contamination, I once remember watching XLPE power cable be manufactured on a triple extrusion CCV line where the insulation was put, pellet by pellet, through a modified rice scanning machine to remove amber pellets. The only problems were that the ambers were ejected by compressed air and the whole system was out in the open beside the extruders. They were most likely adding more contamination than they believed they were removing. Moreover I am not aware of any technical papers stating that ambers degrade the insulation

Regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

Peter,

He did not tell us what kind of wire he was insulating. You can also put 3 different insulations on magnet wire.

A lot of the blown film used to make things from plastic bags to sheet film can have as many as 6 or 7 layers which are co-extruded. I would assume that it would be possible like you say for one reason, the combined thickness of multiple layer blown film is just a fraction of the thickness of most extruded wire.

Hi Spectre,

Thank you for your input.
With reference to triple or multi-layer insulated wire, I have witnessed the manufacture of only four different product lines:

- Magnet Wire
- Power Cable - Plastic
- Power Cable - Paper
- Military Aerospace

I am certainly aware of co-extruded multi-layer films but this is not part of this thread or forum unless part of a wire and cable application.

Best Regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com