Why are there different film supports?

Discussion in 'B&W: Film, Paper, Chemistry' started by laser, Jun 12, 2013.

  1. laser

    laser Advertiser

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    Entire books have been written on the characteristics of various film supports. I review the pros and cons of CTA (aka acetate) and Estar (aka Mylar or polyester) in "Making Kodak Film".

    Briefly:

    Estar has superior dimensional stability and physical strength. It has a memory so it can severely curl in roll film applications and also it light pipes causing fogging. Estar does not out-gas so it can be used in the vacuum of outer space.


    CTA has little memory so works well in roll film applications.
     
  2. AgX

    AgX Member

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    It is a bit more complicated than that.
    These are the main features that had been considered in the past when designing new base materials:

    -) strenght
    -) optical features
    -) coatability
    -) flamability
    -) area/dimension stability
    -) producibility/costs
    -) archival stability


    That plasticity issue might be subsumized under strenght, though should get aposition of ist own, but interestingly I have not found it discussed in literature, though on other occasions.
     
  3. Hexavalent

    Hexavalent Subscriber

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    I've just seen the "Kodak ceases CTA production" announcement morph into fear-mongering things like "ceases movie films production", "ESTAR producation stopped","ceases all film production" etc., etc., (thanks facebook- NOT)

    Bob, could you clarify the situation?

    As I understand it, EK is just not casting their own CTA base, but will outsource it. ESTAR is still in production. Please correct me if I'm wrong.