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Re: [PPLetterpress] Re: Cleaning the washout unit

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  • Jonathan Jarvis
    Agreed-best wishes
    Message 1 of 24 , Dec 2, 2012
    • 0 Attachment
      Agreed-best wishes


      From: Gerald Lange <Bieler@...>;
      To: <PPLetterpress@yahoogroups.com>;
      Subject: [PPLetterpress] Re: Cleaning the washout unit
      Sent: Thu, Nov 29, 2012 6:10:59 AM

       

      Jonathan

      There is a definite color shift between exposed and unexposed material for both the BASF and Toyobo plates. I think it is a great aid in processing as it is more visually revealing of possible problems. It also aids in alignment on the base during the prepress stage. Plus, it just looks more sophisticated than that all bland yellow of the cheaper brands.

      Gerald
      http://BielerPress.blogspot.com

      --- In PPLetterpress@yahoogroups.com, "jonathanjeclipse" <jonathanjeclipse@...> wrote:
      >
      > That is actually interesting, thanks for information, much appreciated
      > I use the Miraclon but also we have had a go at the Tyobo-recently been playing around with a couple of Flint Corp/BASF plates, and even just unwrapped we can smell their essence? in the air and after washing-must check out their data sheet to see if there are more volatile/hazardous? components in case we use them a lot more--I really like that Tyobo change colour according to what stage in the making they have reached, I don't think I am imagining that !-has anyone else experience of Flint plates, they certainly seem to swell up easily and quickly go to the base, cf with Miraclon which seems to be a more gradual process:this when we use the Miraclon d73s for polymer intaglio (as well as letterpress), so found that BASF could not hold the sensitive tones in the surface when making plates for intaglio, yes of course polymer plates are not really designed/ formulated for this but somehow it works, AKA "solar" platemaking(personally I feel that name is not appropiate, better to state the objective ie making a photopolymer intaglio plate)....
      > --- In PPLetterpress@yahoogroups.com, Peter Bruce <pcpete100@> wrote:
      > >
      > > Hi guys,
      > >
      > >
      > > been following this thread with interest but not had time to reply. We've had a little experience with this in the UK which might be useful to somebody - regulations are tight here about waste and chemicals.
      > >
      > > Firstly, some plates we've found can have their effluence flushed into mains sewage in the UK, at least that's the claim. I believe the Miraclon plate is supposed to be one such. The Toyobo plates should not be discharged into main sewage (certainly not in the UK at least - not sure about you fella's over the pond), the issue is the build up of sediment which causes major problems with public sewage services. You can understand this, we all have problems with the stuff sticking to machines and digging out the acetone for a clean up...
      > >
      > > The solution we use is filtration and we've developed a simple homemade process that's cheap but extremely effective. Photopolymer is unstable outside of neutral PH values (4.5-7), whether 8 and above to alkaline or 3 and below to acidic. We empty the bath into a 30 litre tank then add a small amount of caustic solution (sodium hydroxide - available from the hardware store - dissolved into water, the maximum strength is 47% or it turns solid, 20% is used for oven cleaner solutions etc but 10% is fine and relatively safe, though wear gloves obviously) I'm afraid we just use the glug method adding the solution to the waste tank but around 200ml.
      > >
      > > We leave the waste overnight and the next morning all the 'mud' has aggregated to the bottom leaving a completely clear liquid above which we syphon to sewage. The overall PH at this point is probably around that of a household washing machine discharge. The mud we strain through a couple of layers of cotton then squeeze out and again the water is clear just leaving the mud in the cloth which empties easily into a refuse sack.
      > >
      > > For us here this complies with all regulations, the only time used is actually straining the mud which takes around five minutes and occasionally  making another can of caustic solution. I believe acid will work too, you could use something safe like citric or descaler but we've not tried this as the caustic route works fine.
      > >
      > > Sorry, bit of a yarn but somebody may find it useful - apologies to everybody else for a monotonous science lesson.
      > >
      > >
      > > PC.
      > >
      >

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