TECHNET Archives

April 2004

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Brian Ellis <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Sun, 25 Apr 2004 10:00:12 +0300
Content-Type:
text/plain
Parts/Attachments:
text/plain (56 lines)
New? In a former life when I was making PCBs (the late 1960s), I used a
press which had two Dowtherm tanks, one heated, one at room temp and the
platens had serpentines built in. It was very good, as the
heating/cooling profile was regulated by proportional controllers which
adjusted the flow rates of the Dowtherm. The negative point was that the
hot Dowtherm had a relatively short working life, as it was working at
its upper temp limit - maybe there are other fluids more suitable today.
In reality, this didn't bother us too much: it was a small press (about
40 x 30 cm platens from memory) and was not used much, perhaps 20
days/year, as the demand for m/l PCBs was low in those days (and the
prices high!). Again from a failing memory, we replaced 50 l of Dowtherm
about twice per year. However, there is one important point to note:
make sure that the heating system for the fluid has a very large surface
area; Dowtherm does not like ordinary immersion heaters, as the
convection is poor and it can be locally overheated and carbonise.

Brian

Yehuda Weisz - Netvision wrote:
> Hello Everyone,
> I have come across a new Lamination press "technology" and would like to know a bit more about it.
> Several press manufacturers now promote a heating/cooling technology that utilizes a "Thermal fluid" that does all the heat transfer to the heating platens for heating or cooling. This comes instead of the hot oil/electric heating and water cooling and they praise it's efficiency and uniformity.
>
> What I would like to know is whether anyone out there has looked more closely into this technology and has some insight regarding its pros and cons.
> Any input will be greatly appreciated.
>
> Best regards,
> Yehuda
>
>
> Yehuda Weisz
> Tel: (972)-3-6342045
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 1.8e
> To unsubscribe, send a message to [log in to unmask] with following text in
> the BODY (NOT the subject field): SIGNOFF Technet
> To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
> To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
> Search the archives of previous posts at: http://listserv.ipc.org/archives
> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
> -----------------------------------------------------
> Cel: (972)-53-556897
>
>

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2