> Dick,
>
>I've also had something similar in mind, looking at various water
>soluble synthetic polymers such as poly vinyl alcohol, and the modified
>celluloses in order to see how they compared with gum arabic. another
>thing that I had in mind was to look at the effect of using pyridium
>dichromate, and various light sensitising dyes on the printing speed of
>gum systems, as mentioned in Kosar's book 'Light Sensitive Systems'.
Pyridium dichromate. I can't find that in my handbook. My Mercke is at work. Know anything about this magic stuff. Sounds interesting.
>It seems to me that you will have to define the parameters pretty
>rigidly. Starting off with a standard formulation, on a standard
>substrate with a standard light source. Preferably using the same film
>thickness for each test, though how one measures this on paper I'm not
>sure. Perhaps one could use a well sized paper and coat with a meyer bar
>or a spinner, then measure the film weight. Then vary one parameter at a
>time!
No you're not teaching me to suck eggs, I appreciate your input. The problem as you note, is to be able to duplicate each coating and not to enter too many personal variables.
There was a nice thread a year ago on pigments and particle sizes and how to measure them. Very illuminating.
Welcome to the team. I'm going to be a little slow on the startup as the Ziatype article has us running in circles right now.
Dick
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