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  1. #61
    hrst's Avatar
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    The success of the experiment is easy to check quickly by sprinkling water on the sheet. As you say, it runs off on raw polyester, but if the treatment is successful, then it will spread nicely, as I show here: http://www.youtube.com/watch?v=StgbV766dqQ .

  2. #62
    Mustafa Umut Sarac's Avatar
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    Jason,

    Put film in to chemical bath not chemical on to film. May be this would be a solution.

    Umut

  3. #63
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    hrst,

    Thanks for bumping your youtube here. It is just about the best geek-cool thing on the internet. The time stamp on it this morning gave me double-take whiplash, though. Has it really been a year and a half ago since you did that experiment? I'll be really happy when you get time to get back to the emulsion lab!

    ***************
    Umet,

    There really isn't a reason to go with PET over acetate except for how flat ester films still are after they are subbed. Acetate subs easily and cheaply and relatively safely, at least compared to some to the ideas floated here to sub polyester. The problem with it is that the subbing chemistry/process causes it to wrinkle. You almost have to flatten subbed acetate with heat before coating. Coating thickness is only ~ 7-15 mils and so by default the surface topography tolerance of the film is very, very narrow.

    Any chemical that can etch polyester film is likely to cause an uneven surface. Same, of course, for heat. This pretty much defeats the reason for using polyester film. Corona discharge treatment doesn't last long, and can fog emulsion, so (as I understand it from my conversations with Dupont) you want to sub the PET with something hydrophilic immediately after the discharge treatment. Then, that subbing lasts a long time and is emulsion-friendly.

    Anyway, what I'm getting at the long way round, is that if the goal is a diy subbed film, readily at hand for an intended project, think subbed acetate. Do you have a project in mind that requires PET?

    d
    www.thelightfarm.com
    Dedicated to Handmade Silver Gelatin Paper, Film, and Dry Plates.

  4. #64
    kb3lms's Avatar
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    Umut,

    Yes, I agree. Later last night I found some notes on an industrial application of the etching process and that was what was done. I have some PET from a vegetable container soaking in a small container of alkali now.

    -- Jason
    All this has happened before, and all this will happen again.

  5. #65
    rmazzullo's Avatar
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    When I spoke to these folks some years ago, they told me they could supply a clear acetate film leader with a subbing layer or a clear polyester leader as described on their web site (link below). If I remenber correctly, different options available (subbed, different widths, additional layers, etc) were also discussed, but I was primarily asking about the acetate, not the polyester.

    Their web page is at: http://www.filmotec.de/?cat=27&lang=en&lang=en
    The pdf for the material I was looking at back then: http://www.filmotec.de/wp-content/up...-TI-LF3S-e.pdf

    Since the leader is normally supplied in 35 and 16 mm widths, both perforated and non-perforated, you will have to open a dialog with the sales agent at Filmotec to find out what options are available. Back in 2008, the sales manager's e-mail was Frank Böhme, and his e-mail address was "bohme@filmotec.de" (no quotes).

    Bob M.
    Last edited by rmazzullo; 06-10-2012 at 01:13 AM. Click to view previous post history.

  6. #66
    kb3lms's Avatar
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    The success of the experiment is easy to check quickly by sprinkling water on the sheet. As you say, it runs off on raw polyester, but if the treatment is successful, then it will spread nicely...
    So here's some early results. This is using pieces of PET cut out of discarded food containers. For both tests, half the piece of PET was treated and half not.

    1) Sheet wiped with NaOH solution. No noticeable difference in water runoff test. A slightly sticky feel when running your finger across the treated area but the effect doesn't last. Does not look like a viable route.

    2) Overnight soak in NaOH. Water spreads over the treated area and does not run off. Still runs off as expected in untreated area. Treated part of the PET has a cloudy appearance. You can still easily see through it, but it's not as clear as the untreated part.

    Next step I think will be to make a test strip with progressively longer "soaks" in the NaOH and water test. See if I can identify a lower limit on the soak time required.

    -- Jason
    All this has happened before, and all this will happen again.

  7. #67
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    Umut,

    Apologies for misspelling your name earlier. If it's any excuse, half the time I type 'densie' for my own and only about half those times manage to catch it.

    d
    www.thelightfarm.com
    Dedicated to Handmade Silver Gelatin Paper, Film, and Dry Plates.

  8. #68
    Mustafa Umut Sarac's Avatar
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    Denise ,

    you cant believe how many mistakes I was writing to bill of ladings at shipping company I never been able to learn typing with 10 fingers. I was using a letters deleted keyboard until last month and I was going insane

    Umut

  9. #69
    Mustafa Umut Sarac's Avatar
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    Jason,

    Great and quickly made experiment that we dont see frequently at APUG.

    Good luck ,

    Umut

  10. #70
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    Quote Originally Posted by Mustafa Umut Sarac View Post
    Great and quickly made experiment that we dont see frequently at APUG.
    Ditto.

    The result sounds pretty interesting, and just a little bit encouraging... no?
    If you are the big tree, we are the small axe



 

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