- 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.
- Hi Frank,
It looks like nobody is going to quickly respond to this thread but since you have a lot of resources at your disposal, here are my suggestions:
- Graph the ultimate tensile strength (UTS) of the 32 AWG wire or metric equivalent up to failure and the elongation.
- Determine the elastic strength of the wire and with your experience with other metals and determine the maximum elastic force you can impart to each wire.
- Knowing the number of wires on each carrier, calculate the maximum and minimum wire-set forces on each carrier. (Remember that the tension goes up as the diameter of the wire set reduces. - Constant torque.)
- For lubrication, I would recommend the use a very light oil that doesn't promote environmental stress cracking. Talk to your lubricant supplier or manufacturer. Do not over lubricate.
- For a start, the braiding closing die should be very similar to a copper braiding closing die. Some experimentation may be necessary.
- Verify your results by experimentation.
- Peter J Stewart-Hay replied to the topic 'Copper Gets Tarnished after PVC Insulating Part 2' in the forum.Copper(I) Oxide, Cuprous Oxide, Cuprite or Red Copper Oxide (CuO2)
Cuprous Oxide can easily coat the conductor and it is a brownish-red solid. The chemical formula is CuO2 meaning two oxygen atoms combine with one copper atom. (Cu + O2 = CuO2). On copper wire, you can see the cuprous oxide layer in full color as various shades of reds, oranges, pinks, and purples if the copper has been heated too high (Above about 200 degrees Celsius (392 Fahrenheit) and exposed to oxygen. Moreover keep in mind that when copper is hot, it quickly oxidizes (corrodes or rusts) and this is nothing more than a simple chemical reaction with oxygen.
Copper(II) Oxide, Cupric Oxide (CuO)
Cupric Oxide can as well easily coat the conductor and it is a black solid. Large amounts are produced by roasting mixed copper in a furnace at a temperature below 1,030 °C (1,900 °F).
- Peter J Stewart-Hay created a new topic ' Copper Gets Tarnished after PVC Insulating Part 2' in the forum.The original thread was closed almost four years ago and today we received another question from the company. It was sent to my company instead of to the Forums. We have posted that question here as a new thread. The original thread can be viewed below
The new question is:
In PVC compound, which component easily reacts with copper wire and makes the surface tarnished/blackish on our insulated cable . Please share the particular component details for further investigation in this case.
- Peter J Stewart-Hay replied to the topic 'graduation about prestressed wire straightness' in the forum.Hello Mike,
If you click on the "WAI Store" heading at the left and go to Item you will see this booklet:
"We Do it Straight - Wire Straightening"
This book, published by WITELS Apparate-Maschinen Albert GmbH & Co. KG, is a compilation of findings regarding wire straightening systems—and the results achieved with such systems over the years.
$ 20.00 - We Do it Straight (Member Price)
$ 25.00 - We Do it Straight (List Price)
Unfortunately this item is on back order right now.
- Dear Dr Popela,
Since you are dealing with a very hard alloy of platinum , which suggests that the platinum has been alloyed with gold or silver, there is certainly the opportunity for segregation in the casting, sometimes called coring, if not properly done. This is due to the large difference in the melting points of these alloys.
The picture of your wire break does not seem to exhibit the typical cup-cone failure associated with a ductile alloy. Instead it appears that there is evidence of segregation because of the cracking and the different degree of elongation at different points in the wire.
I would therefore conclude that the alloy is non-uniform and therefore was cast improperly.
This approximates my total understanding of platinum and platinum alloy wire drawing technology so I cannot help you more. Perhaps others will but it may take a long time, if ever, to obtain an appropriate response. You therefore may wish to investigate this with the metallurgy department or metallurgical engineering department at a good and nearby university..
- Hello Mr. Martin Gerardp Escobar Angel,
Your issues are the insulation faults at the primary insulation line or between the primary insulation process and the multi-passes under the electron beam head. Moreover, I would be quite surprised if the wire storage temperature of 40C (104F) was creating faults although I am unaware of the polyolefin you are actually using.
The increase in faults during irradiation is normal and due to the insulation failures and the energy imparted by the electron beam head.
I always have concerns about a spinning spooling take up at 900 meters/ minute (About 2950 F.P.M.) and flying off at 850 meters per minute (About 2800 F.P.M.). I would look very carefully at the equipment at the take up with focus on the guides and pulleys where damage could occur. Likewise the same careful inspection must occur at the cone packs including the tension control device which prevents kinking and the inside surface of the cones.
If the extrusion faults are proven to occur at the insulation line, you must review your extrusion practices including extrusion temperatures, the time between shut down and clean out, plus the effectiveness of the clean out. Likewise you should know when and where these faults occur. Perhaps it is near the end of the run before the extrusion line clean out is due or just after the extrusion line had been poorly cleaned out. Finally, there had better no damage to the screw, cross head throat or tooling.