Enamel consumption

Dear Sir

It is an impregnation resin (dobecan-2015-90LEK) from Altana Germany in which sample of 36 wires bunch needs to be dipped for 5 minutes. Then it needs to be put into the oven for 180 minutes at a temperature rising from ambient to 200 degree. After completing this process each and every wire needs bending in S shape on 16 mm rod and there should be no cracks on wire at the bent portion. Wire diameter is 2.24 mm/grade-2/class 200/dual coat.

Who is or are "we"? These are fairly basic questions, however it sometimes takes years to learn.

Magnet Wire 101

i) Please tell me how to calculate consumption of enamel.

One way to calculate enamel or varnish consumption is to place a known amount into you supply tank. Make a mark on the container or measure the depth so that you will know the starting point. Once you have been running for a period of time – either an hour or until you have a full spool (if you have a footage indicator then it does not matter when you do it, other than at least 100 feet for larger sections, a couple of hundred feet for smaller sections.) Replace the enamel consumed by using a measuring container so you will know exactly how much enamel it takes to raise the level to the original level. Now you have some known variables plus others to play with: the amount of enamel used and the number of feet of wire coated, the % solids of the enamel, weight of a known quantity of enamel, and you should be able to determine the weight of the wire processed as well as the weight of the same size bare wire. From here it is just math and some intuition to come to the consumption per pound, kilo or whatever unit you want to use.

With regards to your expertise I want to know some other things also from you.

1) Why blisters takes place on enameled copper strips or wire?
Blisters are the result of solvent that gets trapped in the drying enamel.

2) Why people call excess enamel application which causes roughness on conductor as high point?
For the same reason if you did not have enough enamel they would call it low point. Note you can have high point and not have rough wire. By the way have you looked at the rough wire to see why it is rough?

3) What is the effect of high point on performance of enameled conductor?
Like anything that is produced to a spec, sometime high point wire would be out of spec or not meet the customers standards. Sometimes it may meet a different customers spec. Enameled conductor can have a variety of wall thicknesses such as 90% of single build, single build heavy build, triple, or quad build. In addition to those there is every configuration that a customer may want. The performance of high point wire depends upon the manufacturing process and when compared to similar dimension wire may be perfectly fine. There are too many issues to be definitive.

4) What can be the effect of water hardness, conductivity, pH value on enameled copper conductors performance?
Short term none. Hard water, when it evaporates, leaves residue and this residue can get on the wire, in the pre-annealer tubes, cooling tank, etc. I think this has been discussed previously in this forum.

5) What can be the effect of hardness of copper on enameled copper conductor?
Supposedly the bare wire is not soft when it is supplied to the enameling machine. That is why the system has a pre-annealer and makes numerous passes in the oven to complete or anneal the wire.

6) What is the benefit of using primer?
I have never heard of anyone using a primer on the wire prior to applying the insulating varnish.

Warm Regards

Dear Sir.

What can be the reason for coming high point or low point on enameled copper strip or wire ?
How can I eliminate those ?

Please help.
Regards
Prashant

Hi Prashant;

I suggest you read this Forums thread:

- Viscosity help
www.wirenet.org/forum/viewmessages.cfm?Forum=14&Topic=601

and then for more information, read the following threads:

- Felt Dies
www.wirenet.org/forum/viewmessages.cfm?F...c=447&srow=1&erow=10

- Magnet Wire Failing In PinHole Test
www.wirenet.org/forum/viewmessages.cfm?F...c=792&srow=1&erow=10

- Enameled Copper Wires
www.wirenet.org/forum/viewmessages.cfm?Forum=8&Topic=683

Moreover keep in mind that a clean and smooth conductor with essentially no copper fines on it is a fundamental requirement for manufacturing magnet wire.

Regards
Peter J. Stewart-Hay (WAI Forums Moderator)
Principal
Stewart-Hay Associates
www.Stewart-Hay.com
519 641- 3212

Hi point - low point.

Assuming that the dimension desired is between the hi point and low point, then when you are at the hi or low point you are out of spec. There are a lot of reasons why you might be on one or the other. To narrow down the number of variables you need to know; Was it ever on point or has it always been either hi or low? There are a lot of issues: original set up, enamel conditions, room conditions, bare wire diameters, accurately measuring the wire and on and on.