- About me
- A university trained Professional Mechanical Engineer, registered in the Province of Ontario, Canada.
A wire and cable manufacturing engineering specialist with over 35 years hands on experience.
- Peter J Stewart-Hay replied to the topic 'graduation about prestressed wire straightness' in the forum.Hello Bram,
If you click on the "WAI Store" heading at the left and go to the second page, you will see two books for sale. These are:
- Ferrous Wire Handbook
- Ferrous Wiredrawing Machinery
Click on each book to see the details inside.
The books aren't cheap but they will provide you with the basic information.
If you are not already a member, I suggest you join the Wire Association International before you purchase the books to reduce the selling price.
- Hello again Mohammad and thank you for the resolution of your rough insulation issue.
It never dawned on me that you would be having such a basic or fundamental problem as precure in the extruder barrel as it was my belief that you had much experience in the manufacture of a saline-grafted, moisture cross-linkable polyethylene system.
It just goes to show just how dangerous an assumption can be.
- From Dan Heidel
"Memory alloys can have their atoms arranged in two different atomic lattice arrangements. All metals have different atomic arrangements they can take on but usually they have stable ranges that are separated by very large temperature variations. With the memory alloys, the amount of energy required to shift lattice arrangements is very low.
When you bend them, the physical force triggers the lattice rearrangement wherever the metal is being compressed or stretched (forget which) which give the metal a tremendous ability to reversibly bend.
Some memory alloys just snap back to the original shape when released. I had a pair of glass frames years back that were like this. You could wrap the arms of the glasses around your finger like a corkscrew and they would snap back to the original shape as soon as you let go.
This particular alloy requires a small temperature shift to go back to the original lattice configuration. Tossing the metal into hot water triggers it and it goes back to the original configuration."
I also understand that because of the above,"memory free" steel wire is very stable over very large temperature variations as per the above definition. Thus it is the converse.to the above definition.
- We assume that you are manufacturing a one-shot, three component, saline-grafted, moisture cross-linkable polyethylene system consisting of a proper (Density Please!) XLPE base compound rated for the appropriate voltage, a catalyst master batch approved for use with the base compound and a color concentrate fully compatible with the two other components..
We are however unclear on your statement "masterbatch extruders" as this tends to conflict with a one-shot.extrusion process.
If you are getting a rough surface after extrusion, make sure of the following points: (This is most appropriate for a "one-shot" XLPE colored insulation.)
]1) That the components have been properly sealed before use and that all the components are completely dry.]
]2) That all components are within their shelf lives,and that all have been stored in accordance with the directions on the packages and on the materials sheets.
]3) That all components are all dried before extrusion n accordance with the directions on the packages and the materials sheets.
]4) Gravimetric mixers must be used at the extruder hopper so that all components become an exact concentration mixture by weight and then are precision mixed. Do this at the extruder hopper so there is no random compound segregation by the hopper loading system. Seal or discard any mixed material that was not used in the run. (Left over)
]5) The die must have a land or bearing appropriate to the density of base XLPE material you are using.
These items should resolve your Vinyl Silane XLPE extrusion problem.
- This was sent by to me by Mr Mohammad Zaree
We started extruding XLPE on LV cables and we have problem with it. It occurs in most of the sizes.
The outside surface of the insulation become rough after coming out of the cooling water in all the colors..
We tried to adjust most things but nothing worked. We changed the temperature zones, exchanging the master batch extruders with the insulation extruders,but no improvement.
The problem still remains. If some one could help us we would be really appreciative.