Capacitors containing PCB's

[ScottI2R]

Hi all,
I have been tasked by a customer of ours to tell them if our machinery contains any components that pose a "green" hazard. I know we use merc relays and lithium batteries, but I do not know if any of our EDM generators contain capacitors containing PCB's. We have been building EDM generators since the mid 60's so the posibility definately exists. Can anyone tell me when PCB use in capacitor mfg. stopped? ( Mallory switched in 1978.) I've tried google and the forum search, and it looks as the late 70's or early 80's. We had some new designs in the 80's and I do not know what to tell the person about these models.

Thanks in advance,
Scott

In a hundred years, it isn't going to matter anyway.

 

[afterhrs]

ScottI2R,
I hope you work for a company that keeps excellent records. I would get the serial number from each machine sold to that customer and check the bill of material in
the original build specifications. The bill of material
might also include the date and companies for all
purchased components that went into each machine. Contact each capacitor manufacturer and ask when they stopped using
PCB's
Do not forget that JIT (just in time) did not exist in the 60's and 70's, so one can only guess at how long an item was "on the shelf" before it was sold.
Your only other option is to go take a sample from
each capacitor(destroy it) and send it out for testing.
If your customer makes a really strong push for the information, the above should calm them right down
A very strong possiblity exist that all your purchasing records were not kept and you will have to simply say " the possiblity exist."

Good luck,
Afterhrs

 

[afterhrs]

One more thought, go to the Chemical or Enviromental engineering forums and ask the same question.

Best regards,
Afterhrs

 

[itsmoked]

Don't forget the "evil" lead that's in everything.

 

[VEBill]

Sounds like a marketing opportunity to me...

 

[ScottI2R]

Thanks All,
Afterhrs, We are lucky to have S/W for the CNC's we have built in the late 80's! RECORDS!!! Actually, in the letter drafted by none other than I, we did state exactly that about the "possibility exists."

Itsmoked: Are you referring to that tasty substance that is all over my hands today after soldering pipes for a DI system?

VE1BLL: WHAT AN EXCELLENT IDEA!!!! We can offer to "STERILIZE" the system and insure that when it finally reaches the bone yard, it wont cause 6-toe'd babies a hundred years from now for the people drinking from the water table 2 miles away from its final resting place! By the way, just what does your handle mean? I think about this EVERY time I read a post of yours.

Scott

In a hundred years, it isn't going to matter anyway.

 

[VEBill]

VE1BLL = ham radio call sign.

 

[RalphChristie]

Scott

Maybe this can help?

http://chppm-

http://www.apgea.army.mil/hmwp/Factsheets/ballasts.html

and

http://www.ec.gc.ca/pcb/pcb23/eng/s4_e.htm

(capacitor manufacturers in Canada and USA)

Also, can you please explain the term "EDM generators"?

Regards
Ralph

 

[itsmoked]

Ralph, EDM => Electrical Discharge Machining.

EDM is used when ever you need to machine things in strange places to 0.0001" tolerances. Essentially an arc erosin process done under a liquid.

EDM machines have a complex power supply to control all this. I would guess they are called "EDM generators".

 

[ScottI2R]

Oh, thanks VE1Bll. I thought it was some kind of acronym.

Thanks for the links Ralph. And "itsmoked" summed it up in a nutshell. EDM process and all.
In general, we refer to the power supply as "the generator." High freq. pulsed DC is the output. Duty cycle, on time / off time are all user selectable as well as current levels. This is pretty standard on ALL edm power supplies. Our "dumb" ones just provide the edm power as decribed above. These require some sort of external servo control over the cutting tool known as the electrode. This electrode can be Tungsten wire, tungsten-carbide, graphite, copper, brass, etc.... Now, more "intelligent" generators exist that have the servo controller built in as well as I/O to control simple machine functions (part loaders) and some axis movement like indexers. More expensive top end units are complete edm CNC maching centers. Raycon (my employer) had originally held a patent in this industry for a process called "adaptive control." The way this worked was a part (say a fuel injector nozzle), is drill and then a fluid is passed through it on an integrated flow test stand. The generator's cpu looks at the results as compared to the target value and 1) makes the necessary power adjustment if needed, and 2) instructs the part handling automation (plc) to accept or reject the said part. Jeez....I am starting to sound like I'm in sales! Oh, the fluid is referred to as the di-electric and in most cases is and deionized water (>10M preferred) or DI oil (kerosene based stinky stuff) usually used on die sinker types.
I was told when I hired in 15 years ago, that the EDM process was originally called "Method X."

Hope this sheds some light on the subject......By the way, when people have troubles with their systems and I am on site, I usually just shrug my shoulders and say "Well, ya know, it's electricity and water."

Scott

In a hundred years, it isn't going to matter anyway.

 

[itsmoked]

I2R Are you saying that they flowed the fuel injectors and then EDM'd into spec automatically?

Doesn't that deionized water get ionized real fast when you start eroding metal in it?

 

[ScottI2R]

Itsmoked,
Yes and no. The injector was tested after drilling on the original systems of the mid to late 80's. Now in this century, we have produced some pc-based systems that would do part to part adaptive as well as hole to hole adaptive. I personally installed three of these systems over in Japan in 2000. Boy, the first one was a disaster! (The PC ate itself which added about a week to the trip!)

Most "after machining" test stands use a fluid similar in viscosity to the actual fuel that the injector will be used for. The systems that do hole to hole use water and require a correlation factor to be applied.

People run their DI water two different ways. 1. Recirc'd through filter and chiller systems or 2. Plant water that has a central DI system in which they just dipose of the water down the drain, or recover it and reuse it.

By the way, the water is chilled to minimize molten metal from re-attaching to the hole being drilled. A problem known as "recast."

Scott

In a hundred years, it isn't going to matter anyway.

 

[itsmoked]

I2R Thanks for that added info!

 

[RalphChristie]

Scott and itsmoked:

Thanks for the clarification. I am in the power electric field, thus more familiar with generator as a rotating electrical machine. This is a worldwide forum, and I am not always used to all the different terms. But, I have to admit, never heard of this process. Indeed very interesting.

Regards
Ralph