Subject: Making plastic from milk?

The science fair project my daughter choose last year was Lets make Plastic
from a 7th grade Science book .  It was suppose to mix  whole milk,and 
vinegar,
and heat it. She changed it to investigate the effect of different kind of
milks (skim, soy formula, and whole milk) to make the plastic.  She was
eliminated because the jury said: "Thats not plastic, that is cheese!"  My
question is: Is possible make some kind of plastic from milk? Is there some
kind of a primitive plastic or something?  (I am an English as a Second
Language speaker, please sorry about my English)  Thank for your help.

Nayda E. (a worry mother)

Re: Making plastic from milk?