make up natural cara make up make up tutorial make up korea make up minimalis make up artis make up mata belajar make up make up wardah alat make up makeup forever indonesia makeup artist jakarta tips make up barbie make up natural make up make up wajah make up pesta make up syahrini makeup mata makeup minimalis peralatan make up make up cantik make up mac make up kit jual make up make up sederhana perlengkapan make up gambar make up vidio make up cara makeup minimalis wardah make up make up pac make up glamour cara memakai makeup make up panggung harga make up make up modern make up alami make up dasar pixy make up make up muslimah make up oriflame make up jepang makeover cosmetic make up ultima make up sariayu grosir make up makeup fantasi makeup pesta tas makeup langkah make up make up pria make up malam alat makeup tahapan make up produk make up shading make up mak up make up kebaya make up jilbab make up inez make up simpel contoh make up cara ber makeup makeup wajah tanpa make up make up terbaru toko make up mac makeup indonesia make up soft urutan make up trik make up makeover makeup brand gusnaldi make up paket make up panduan make up jual makeup brush make up bagus alat2 make up make up gusnaldi aplikasi make up alat alat makeup dasar make up inez make up peralatan makeup make up wanita make up berjilbab make up tebal sejarah make up make up maybeline make up branded make up siang tata cara makeup reseller make up make up muslim make up maybelin warna make up tips make up artist rias make up make up mata make up artis belajar make up make up artist kursus make up kuas make up make up forever indonesia jual make up mac indonesia make up make up artist indonesia harga make up forever jual make up online make up pac make up forever jakarta make up oriflame jual make up forever make up online shop indonesia harga make up sekolah make up grosir make up harga make up maybelline jual make up murah make up terbaru mak up mac make up indonesia sofia make up make up kit murah mac makeup indonesia produk make up jual make up kit make up store indonesia make up forever academy jakarta toko make up online jual make up set jual make up mac make up beauty jual make up branded produk make up mac make up forever harga make up mac indonesia produk make up artis jual make up palette produk make up forever make up palette murah before after make up pengantin before after make up sendiri before n after hasil makeup contoh make up karakter contoh riasan pengantin before n after harga make up wisuda harga make up artist harga make up forever make up wisuda rias wisuda di jogja Daftar harga make up forever daftar harga make up mac daftar harga kosmetik make up forever makeup wisuda harga makeup wisuda kursus make up di yogyakarta kursus make up di jogja kursus make up jogja kursus make up yogyakarta kursus kecantikan di yogyakarta kursus kecantikan di jogja kursus make up artist di jogja kursus rias pengantin di jogja kursus rias di yogyakarta kursus tata rias di yogyakarta rias pengantin muslim jogja jasa kreasi jilbab wisuda yogyakarta jasa rias make up wisuda murah bagus bisa dpanggil tempat make uf di jigja yang bagus rias wisuda murah dan berkualitas yogyakarta pakar kreasi jilbab di jogja make uper natural yogya make up wisuda hijab area jogja make up dan kreasi jilbab yang bagus di jogja jasa make up natural untuk wisuda jogja makeup jogja make up jogja makeup yogyakarta make up yogyakarta makeup wisuda jogja make up wisuda jogja make up wisuda yogyakarta makeup wisuda yogyakarta
Search - Content
Search - People/Events
Search - Forums
Search - Newsfeeds



jobcenterbanner

FacebookLinkedinPinterestYoutube
Welcome, Guest
Username: Password: Remember me
If you have a question regarding coaxial, telephone, and building wire, power cable, insulation, extrusion, bunching, stranding, braiding, etc. post it here.
  • Page:
  • 1
  • 2

TOPIC: Heat Shock & Peel test Enamel Copper Wire

Re: Heat Shock & Peel test Enamel Copper Wire 2 years 6 months ago #667

Hello amirkhi,

We note that you are a process or perhaps chemical engineering consultant to the actual magnet wire manufacturer.

It is impossible for us to understand exactly how you are running your tests in the plant and your latest eleven word answer is surely not helping.

You did not confirm Spectre's comment:

"I assume by not getting the proper results you mean that the wire coil when you remove it from the test oven is cracked."

Spectre also asked:

"How are your cut through values, DF values, etc. If they are very good (high) that would support the thought that you may be slightly overcuring the wire."

You did not answer that!

Likewise you did not tell us anything about your recent experiments other than the fact that the insulation failed again somehow. We received no specific data from you at all in regards to what experimentation you did at the plant and we cannot read your mind! We don't even know if your insulation thickness is uniform! You have also not told us anything else such as the type of enamel, type of machine(s), if the problem is universal to a number of ovens or only one (Was that checked?), etc. etc.

How are we supposed to help you when you don't tell us anything except that you have a problem? We don't even know what standard you are referring to.

Because you have given us only the broadest general information, we can, in return, only give you very generalized technical advice:

(1) What you are going to have to do is set up a series of proper and tightly controlled experiments to prove or disprove the possibility that overcuring of the insulation is indeed occurring. We assume by this statement that you have good experience and training in the design of experiments.

(2) Once (1) is complete and if the problem is still not resolved, talk over the problem (with full and specific details) with the enamel manufacturer just in case you have a bad or very old lot of material.

Good luck with your experiments.

Kindest regards,
Peter J. Stewart-Hay (WAI Forums Moderator)
Principal
Stewart-Hay Associates
www.Stewart-Hay.com
The administrator has disabled public write access.

Re: Heat Shock & Peel test Enamel Copper Wire 2 years 6 months ago #668

Cracking of the insulation from a mandrel wrap on copper wires can be caused by under cured or over cured coatings.Some or most polymers react differently in these circumstances. Sometimes, (and this may be you're case) that the coating is fine and the copper may be the problem. Some alloys tend to get surface cracks when bent in tight radius's causing the coating to appear to be cracking. The best way to verify coating cure is by Dissipation factor vs temperature. The Dansk system www.dse.dk is a popular piece of equipment for measuring this.
The administrator has disabled public write access.

Re: Heat Shock & Peel test Enamel Copper Wire 2 years 6 months ago #669

Hello Tech1; haven't heard from you in a long time.

You are of course right about cracking from over cure/under cure. Typically unless the wire is dramatically under cured, the heat shock test procedure will further cure the wire plus wire that cracks from under cure looks different than wire that cracks from over cure. Sometimes under cured wire will crack when winding the coil - the solids in the enamel are not (cannot think of the correct word) unified. If the enamel is colored it may be either darker or in some cases the color will be faded.

DF is a good test and the enamel manufactures will provide you a range in which good wire will fall within. To utilize DF you need to profile and develop curves for each oven because even identical ovens operating with the same temperature and wire speed may not have the same DF.

Also the wire may be within the recommended DF range and it could still fail the heat shock test.

A pull mandrel test is also a good test of the quality of the insulation. Wire that passes pull mandrel test, should pass heat shock.

Tech1 has worked with a variety of alloys, but for copper wire, the situation he mentions should not matter--unless the copper is not very good. You can wrap the bare wire around a mandrel it's the same diameter of the wire and then look at it under a 5-10X scope of loop to see if there is cracking.

Peter thanks for asking for more info.
The administrator has disabled public write access.

Re: Heat Shock & Peel test Enamel Copper Wire 2 years 6 months ago #670

just wondering if situation has improved or if there are any answers to Peter's questions.
The administrator has disabled public write access.

Re: Heat Shock & Peel test Enamel Copper Wire 2 years 6 months ago #671

Hi Amirkhi

I've experienece with this before when produce a sample to a famous motor producer. The wire sample failed few times in heat shock test and ultimately I found that the varnish / enamel is the main factor to give excellent heat shock properties. Believe or not, you can request your enamel supplier give you some "imide" modify enamel sample to try (excellent resistance to heat shock).
Regarding the undercure or overcured, I agreed that this is one of the factors. However I have done testing previously with various speed in order to produce some samples of overcure or undercure wires but the result is all fail with NEMA Heat Shock test. On contrary, I use another type of enamel with excellent resistance to heat shock (thermal), I produce few samples with undercure and overbake, they all PASS. BTW, I have to agree that in the first scenario that the overbake insulation crack "more" if compare with "under bake" wires.

Hope help

Have a nice day everybody

JIT
The administrator has disabled public write access.

Re: Heat Shock & Peel test Enamel Copper Wire 2 years 6 months ago #672

there are several different types of insulating varnish or enamel. they are also some that are used as overcoats or in between coats. Depending upon the varnish used, the thermal rating of the wire will vary. Without knowing what material you are using, it is somewhat difficult to know what standard you are testing to.
The administrator has disabled public write access.
  • Page:
  • 1
  • 2
Time to create page: 0.307 seconds